Search results for: non-linear phase shift
6280 A Study on Approximate Controllability of Impulsive Integrodifferential Systems with Non Local Conditions
Authors: Anandhi Santhosh
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In order to describe various real-world problems in physical and engineering sciences subject to abrupt changes at certain instants during the evolution process, impulsive differential equations has been used to describe the system model. In this article, the problem of approximate controllability for nonlinear impulsive integrodifferential equations with state-dependent delay is investigated. We study the approximate controllability for nonlinear impulsive integrodifferential system under the assumption that the corresponding linear control system is approximately controllable. Using methods of functional analysis and semigroup theory, sufficient conditions are formulated and proved. Finally, an example is provided to illustrate the proposed theory.Keywords: approximate controllability, impulsive differential system, fixed point theorem, state-dependent delay
Procedia PDF Downloads 3836279 A Stochastic Model to Predict Earthquake Ground Motion Duration Recorded in Soft Soils Based on Nonlinear Regression
Authors: Issam Aouari, Abdelmalek Abdelhamid
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For seismologists, the characterization of seismic demand should include the amplitude and duration of strong shaking in the system. The duration of ground shaking is one of the key parameters in earthquake resistant design of structures. This paper proposes a nonlinear statistical model to estimate earthquake ground motion duration in soft soils using multiple seismicity indicators. Three definitions of ground motion duration proposed by literature have been applied. With a comparative study, we select the most significant definition to use for predict the duration. A stochastic model is presented for the McCann and Shah Method using nonlinear regression analysis based on a data set for moment magnitude, source to site distance and site conditions. The data set applied is taken from PEER strong motion databank and contains shallow earthquakes from different regions in the world; America, Turkey, London, China, Italy, Chili, Mexico...etc. Main emphasis is placed on soft site condition. The predictive relationship has been developed based on 600 records and three input indicators. Results have been compared with others published models. It has been found that the proposed model can predict earthquake ground motion duration in soft soils for different regions and sites conditions.Keywords: duration, earthquake, prediction, regression, soft soil
Procedia PDF Downloads 1536278 Numerical Analysis of the Melting of Nano-Enhanced Phase Change Material in a Rectangular Latent Heat Storage Unit
Authors: Radouane Elbahjaoui, Hamid El Qarnia
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Melting of Paraffin Wax (P116) dispersed with Al2O3 nanoparticles in a rectangular latent heat storage unit (LHSU) is numerically investigated. The storage unit consists of a number of vertical and identical plates of nano-enhanced phase change material (NEPCM) separated by rectangular channels in which heat transfer fluid flows (HTF: Water). A two dimensional mathematical model is considered to investigate numerically the heat and flow characteristics of the LHSU. The melting problem was formulated using the enthalpy porosity method. The finite volume approach was used for solving equations. The effects of nanoparticles’ volumetric fraction and the Reynolds number on the thermal performance of the storage unit were investigated.Keywords: nano-enhanced phase change material (NEPCM), phase change material (PCM), nanoparticles, latent heat storage unit (LHSU), melting.
Procedia PDF Downloads 4076277 Investigation of Overstrength of Dual System by Non-Linear Static and Dynamic Analyses
Authors: Nina Øystad-Larsen, Miran Cemalovic, Amir M. Kaynia
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The nonlinear static and dynamic analysis procedures presented in EN 1998-1 for the structural response of a RC wall-frame building are assessed. The structure is designed according to the guidelines for high ductility (DCH) in 1998-1. The finite element packages SeismoStruct and OpenSees are utilized and evaluated. The structural response remains nearly in the elastic range even though the building was designed for high ductility. The overstrength is a result of oversized and heavily reinforced members, with emphasis on the lower storey walls. Nonlinear response history analysis in the software packages give virtually identical results for displacements.Keywords: behaviour factor, dual system, OpenSEES, overstrength, seismostruct
Procedia PDF Downloads 4076276 Structural Magnetic Properties of Multiferroic (BiFeO3)1−x(PbTiO3)x Ceramics
Authors: Mohammad Shariq, Davinder Kaur
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A series of multiferroic (BiFeO3)1−x(PbTiO3)x [x= 0, 0.1, 0.2, 0.3, 0.4 and 0.5] solid solution ceramics were synthesised by conventional solid-state reaction method. Well crystalline phase has been optimized at sintering temperature of 950°C for 2 hours. X rays diffraction studies of these ceramics revealed the existence of a morphotropic phase boundary (MPB) region in this system, which exhibits co-existence of rhombohedral and tetragonal phase with a large tetragonality (c/a ratio) in the tetragonal phase region. The average grain size of samples was found to be between 1-1.5 µm. The M-H curve revealed the BiFeO3 (BFO) as antiferromanetic material whereas, induced weak ferromagnetism was observed for (BiFeO3)1−x(PbTiO3)x composites with x=0.1, 0.2, 0.3, 0.4 and 0.5 at temperature of 5 K. The results evidenced the destruction of a space-modulated spin structure in bulk materials, via substituent effects, releasing a latent magnetization locked within the cycloid. Relative to unmodified BiFeO3, modified BiFeO3-PbTiO3 -based ceramics revealed enhancement in the electric-field-induced polarization.Keywords: BiFeO3)1−x(PbTiO3)x ceramic, multiferroic, SQUID, magnetic properties
Procedia PDF Downloads 3466275 3D Numerical Studies on External Aerodynamics of a Flying Car
Authors: Sasitharan Ambicapathy, J. Vignesh, P. Sivaraj, Godfrey Derek Sams, K. Sabarinath, V. R. Sanal Kumar
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The external flow simulation of a flying car at take off phase is a daunting task owing to the fact that the prediction of the transient unsteady flow features during its deployment phase is very complex. In this paper 3D numerical simulations of external flow of Ferrari F430 proposed flying car with different NACA 9618 rectangular wings have been carried. Additionally, the aerodynamics characteristics have been generated for optimizing its geometry for achieving the minimum take off velocity with better overall performance in both road and air. The three-dimensional standard k-omega turbulence model has been used for capturing the intrinsic flow physics during the take off phase. In the numerical study, a fully implicit finite volume scheme of the compressible, Reynolds-Averaged, Navier-Stokes equations is employed. Through the detailed parametric analytical studies we have conjectured that Ferrari F430 flying car facilitated with high wings having three different deployment histories during the take off phase is the best choice for accomplishing its better performance for the commercial applications.Keywords: aerodynamics of flying car, air taxi, negative lift, roadable airplane
Procedia PDF Downloads 4206274 Determination of Thermal Properties of Crosslinked EVA in Outdoor Exposure by DSC, TSC and DMTA Methods
Authors: Kamel Agroui, George Collins, Rydha Yaiche
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The objective of this study is to better understand the thermal characteristics and molecular behaviour of cured EVA before and after outdoor exposure. Thermal analysis methods as DSC, TSC and DMTA studies were conducted on EVA material. DSC experiments on EVA show a glass transition at about -33.1° C which is characteristic of crystalline phase and an endothermic peak at temperature of 55 °C characteristic of amorphous phase. The magnitude of the integrated temperature DSC peak for EVA is 14.4 J/g. The basic results by TSC technique is that there are two relaxations that are reproducibly observed in cured EVA encapsulant material. At temperature polarization 85°C, a low temperature relaxation occurs at –24.4°C and a high temperature relaxation occurs at +30.4ºC. DMTA results exhibit two tan peaks located at -14.9°C and +66.6°C. After outdoor exposure cured EVA by DSC analysis revealed two endothermic peaks due to post crystallization phenomenon and TSC suggests that prolonged exposure selectively effects the poly(vinyl acetate)-rich phase, with much less impact on the polyethylene-rich phase.Keywords: EVA, encapsulation process, PV module, thermal analysis, quality control
Procedia PDF Downloads 556273 Managing the Cloud Procurement Process: Findings from a Case Study
Authors: Andreas Jede, Frank Teuteberg
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Cloud computing (CC) has already gained overall appreciation in research and practice. Whereas the willingness to integrate cloud services in various IT environments is still unbroken, the previous CC procurement processes run mostly in an unorganized and non-standardized way. In practice, a sufficiently specific, yet applicable business process for the important acquisition phase is often lacking. And research does not appropriately remedy this deficiency yet. Therefore, this paper introduces a field-tested approach for CC procurement. Based on an extensive literature review and augmented by expert interviews, we designed a model that is validated and further refined through an in-depth real-life case study. For the detailed process description, we apply the event-driven process chain notation (EPC). The gained valuable insights into the case study may help CC research to shift to a more socio-technical area. For practice, next to giving useful organizational instructions we will provide extended checklists and lessons learned.Keywords: cloud procurement process, IT-organization, event-driven process chain, in-depth case study
Procedia PDF Downloads 3936272 Total Controllability of the Second Order Nonlinear Differential Equation with Delay and Non-Instantaneous Impulses
Authors: Muslim Malik, Avadhesh Kumar
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A stronger concept of exact controllability which is called Total Controllability is introduced in this manuscript. Sufficient conditions have been established for the total controllability of a control problem, governed by second order nonlinear differential equation with delay and non-instantaneous impulses in a Banach space X. The results are obtained using the strongly continuous cosine family and Banach fixed point theorem. Also, the total controllability of an integrodifferential problem is investigated. At the end, some numerical examples are provided to illustrate the analytical findings.Keywords: Banach fixed point theorem, non-instantaneous impulses, strongly continuous cosine family, total controllability
Procedia PDF Downloads 2986271 A Fault Analysis Cracked-Rotor-to-Stator Rub and Unbalance by Vibration Analysis Technique
Authors: B. X. Tchomeni, A. A. Alugongo, L. M. Masu
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An analytical 4-DOF nonlinear model of a de Laval rotor-stator system based on Energy Principles has been used theoretically and experimentally to investigate fault symptoms in a rotating system. The faults, namely rotor-stator-rub, crack and unbalance are modelled as excitations on the rotor shaft. Mayes steering function is used to simulate the breathing behaviour of the crack. The fault analysis technique is based on waveform signal, orbits and Fast Fourier Transform (FFT) derived from simulated and real measured signals. Simulated and experimental results manifest considerable mutual resemblance of elliptic-shaped orbits and FFT for a same range of test data.Keywords: a breathing crack, fault, FFT, nonlinear, orbit, rotor-stator rub, vibration analysis
Procedia PDF Downloads 3086270 Vacancy-Driven Magnetism of GdMnO₃
Authors: Matúš Mihalik, Martin Vavra, Kornel Csach, Marián Mihalik
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GdMnO₃ belongs to orthorhombically distorted, GdFeO₃-type family of perovskite compounds. These compounds are naturally vacant and the amount of vacancies depend on the sample preparation conditions. Our GdMnO₃ samples were prepared by float zone method and the vacancies were controlled using an air, Ar and O₂ preparation atmosphere. The highest amount of vacancies was found for sample prepared in Ar atmosphere, while the sample prepared in O₂ was observed to be almost vacancy-free. The magnetic measurements indicate that the preparation atmosphere has no impact on Néel temperature (TN ~ 42 K), however, it has strong impact on the incommensurate antiferromagnetic (IC) to canted A-type weak ferromagnetic (AWF) phase transition at T1: T1 = 23.4 K; 18 K and 6.7 K for samples prepared in Ar; air and O₂ atmosphere; respectively. The hysteresis loop measured at 2 K has a butterfly-type shape with the remnant magnetization (Mr) of 0.6 µB/f.u. for Ar and air sample, while Mr = 0.3 µB/f.u. for O₂ sample. The shape of the hysteresis loop depends on the preparation atmosphere in magnetic fields up to 1.5 T, but is independent for higher magnetic fields. The coercive field of less than 0.06 T and the maximum magnetic moment of 6 µB/f.u. at magnetic field µ0H = 7 T do not depend on the preparation atmosphere. All these findings indicate that only AWF phase of GdMnO₃ compound is directly affected by the vacancies in the system, while IC phase and the field induced ferroelectric phase are not affected.Keywords: magnetism, perovskites, sample preparation, magnetic phase transition
Procedia PDF Downloads 1096269 A General Approach to Define Adjoint of Linear and Non-linear Operators
Authors: Mehdi Jafari Matehkolaee
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In this paper, we have obtained the adjoint of an arbitrary operator (linear and nonlinear) in Hilbert space by introducing an n-dimensional Riemannian manifold. This general formalism covers every linear operator (non – differential) in Hilbert space. In fact, our approach shows that instead of using the adjoint definition of an operator directly, it can be obtained directly by relying on a suitable generalized space according to the action of the operator in question. For the case of nonlinear operators, we have to change the definition of the linear operator adjoint. But here, we have obtained an adjoint of these operators with respect to the definition of the derivative of the operator. As a matter of fact, we have shown one of the straight applications of the ''Frechet derivative'' in the algebra of the operators.Keywords: adjoint operator, non-linear operator, differentiable operator, manifold
Procedia PDF Downloads 1196268 A Multiobjective Damping Function for Coordinated Control of Power System Stabilizer and Power Oscillation Damping
Authors: Jose D. Herrera, Mario A. Rios
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This paper deals with the coordinated tuning of the Power System Stabilizer (PSS) controller and Power Oscillation Damping (POD) Controller of Flexible AC Transmission System (FACTS) in a multi-machine power systems. The coordinated tuning is based on the critical eigenvalues of the power system and a model reduction technique where the Hankel Singular Value method is applied. Through the linearized system model and the parameter-constrained nonlinear optimization algorithm, it can compute the parameters of both controllers. Moreover, the parameters are optimized simultaneously obtaining the gains of both controllers. Then, the nonlinear simulation to observe the time response of the controller is performed.Keywords: electromechanical oscillations, power system stabilizers, power oscillation damping, hankel singular values
Procedia PDF Downloads 5926267 One-Dimensional Numerical Simulation of the Nonlinear Instability Behavior of an Electrified Viscoelastic Liquid Jet
Authors: Fang Li, Xie-Yuan Yin, Xie-Zhen Yin
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Instability and breakup of electrified viscoelastic liquid jets are involved in various applications such as inkjet printing, fuel atomization, the pharmaceutical industry, electrospraying, and electrospinning. Studying on the instability of electrified viscoelastic liquid jets is of theoretical and practical significance. We built a one-dimensional electrified viscoelastic model to study the nonlinear instability behavior of a perfecting conducting, slightly viscoelastic liquid jet under a radial electric field. The model is solved numerically by using an implicit finite difference scheme together with a boundary element method. It is found that under a radial electric field a viscoelastic liquid jet still evolves into a beads-on-string structure with a thin filament connecting two adjacent droplets as in the absence of an electric field. A radial electric field exhibits limited influence on the decay of the filament thickness in the nonlinear evolution process of a viscoelastic jet, in contrast to its great enhancing effect on the linear instability of the jet. On the other hand, a radial electric field can induce axial non-uniformity of the first normal stress difference within the filament. Particularly, the magnitude of the first normal stress difference near the midpoint of the filament can be greatly decreased by a radial electric field. Decreasing the extensional stress by a radial electric field may found applications in spraying, spinning, liquid bridges and others. In addition, the effect of a radial electric field on the formation of satellite droplets is investigated on the parametric plane of the dimensionless wave number and the electrical Bond number. It is found that satellite droplets may be formed for a larger axial wave number at a larger radial electric field. The present study helps us gain insight into the nonlinear instability characteristics of electrified viscoelastic liquid jets.Keywords: non linear instability, one-dimensional models, radial electric fields, viscoelastic liquid jets
Procedia PDF Downloads 3916266 CFD Analysis of Multi-Phase Reacting Transport Phenomena in Discharge Process of Non-Aqueous Lithium-Air Battery
Authors: Jinliang Yuan, Jong-Sung Yu, Bengt Sundén
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A computational fluid dynamics (CFD) model is developed for rechargeable non-aqueous electrolyte lithium-air batteries with a partial opening for oxygen supply to the cathode. Multi-phase transport phenomena occurred in the battery are considered, including dissolved lithium ions and oxygen gas in the liquid electrolyte, solid-phase electron transfer in the porous functional materials and liquid-phase charge transport in the electrolyte. These transport processes are coupled with the electrochemical reactions at the active surfaces, and effects of discharge reaction-generated solid Li2O2 on the transport properties and the electrochemical reaction rate are evaluated and implemented in the model. The predicted results are discussed and analyzed in terms of the spatial and transient distribution of various parameters, such as local oxygen concentration, reaction rate, variable solid Li2O2 volume fraction and porosity, as well as the effective diffusion coefficients. It is found that the effect of the solid Li2O2 product deposited at the solid active surfaces is significant on the transport phenomena and the overall battery performance.Keywords: Computational Fluid Dynamics (CFD), modeling, multi-phase, transport phenomena, lithium-air battery
Procedia PDF Downloads 4516265 Analysis of Nonlinear and Non-Stationary Signal to Extract the Features Using Hilbert Huang Transform
Authors: A. N. Paithane, D. S. Bormane, S. D. Shirbahadurkar
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It has been seen that emotion recognition is an important research topic in the field of Human and computer interface. A novel technique for Feature Extraction (FE) has been presented here, further a new method has been used for human emotion recognition which is based on HHT method. This method is feasible for analyzing the nonlinear and non-stationary signals. Each signal has been decomposed into the IMF using the EMD. These functions are used to extract the features using fission and fusion process. The decomposition technique which we adopt is a new technique for adaptively decomposing signals. In this perspective, we have reported here potential usefulness of EMD based techniques.We evaluated the algorithm on Augsburg University Database; the manually annotated database.Keywords: intrinsic mode function (IMF), Hilbert-Huang transform (HHT), empirical mode decomposition (EMD), emotion detection, electrocardiogram (ECG)
Procedia PDF Downloads 5806264 Noise and Thermal Analyses of Memristor-Based Phase Locked Loop Integrated Circuit
Authors: Naheem Olakunle Adesina
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The memristor is considered as one of the promising candidates for mamoelectronic engineering and applications. Owing to its high compatibility with CMOS, nanoscale size, and low power consumption, memristor has been employed in the design of commonly used circuits such as phase-locked loop (PLL). In this paper, we designed a memristor-based loop filter (LF) together with other components of PLL. Following this, we evaluated the noise-rejection feature of loop filter by comparing the noise levels of input and output signals of the filter. Our SPICE simulation results showed that memristor behaves like a linear resistor at high frequencies. The result also showed that loop filter blocks the high-frequency components from phase frequency detector so as to provide a stable control voltage to the voltage controlled oscillator (VCO). In addition, we examined the effects of temperature on the performance of the designed phase locked loop circuit. A critical temperature, where there is frequency drift of VCO as a result of variations in control voltage, is identified. In conclusion, the memristor is a suitable choice for nanoelectronic systems owing to a small area, low power consumption, dense nature, high switching speed, and endurance. The proposed memristor-based loop filter, together with other components of the phase locked loop, can be designed using memristive emulator and EDA tools in current CMOS technology and simulated.Keywords: Fast Fourier Transform, hysteresis curve, loop filter, memristor, noise, phase locked loop, voltage controlled oscillator
Procedia PDF Downloads 1866263 On the Seismic Response of Collided Structures
Authors: George D. Hatzigeorgiou, Nikos G. Pnevmatikos
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This study examines the inelastic behavior of adjacent planar reinforced concrete (R.C.) frames subjected to strong ground motions. The investigation focuses on the effects of vertical ground motion on the seismic pounding. The examined structures are modeled and analyzed by RUAUMOKO dynamic nonlinear analysis program using reliable hysteretic models for both structural members and contact elements. It is found that the vertical ground motion mildly affects the seismic response of adjacent buildings subjected to structural pounding and, for this reason, it can be ignored from the displacement and interstorey drifts assessment. However, the structural damage is moderately affected by the vertical component of earthquakes.Keywords: nonlinear seismic behavior, reinforced concrete structures, structural pounding, vertical ground motions
Procedia PDF Downloads 5926262 Effectiveness of Damping Devices on Coupling Beams of 15-story Building Based on Nonlinear Analysis Procedures
Authors: Galih Permana, Yuskar Lase
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In recent years, damping device has been experimentally studied to replace diagonally reinforced coupling beams, to mitigate rebar congestion problem. This study focuses on evaluating the effectiveness of various damping devices in a high-rise building. The type of damping devices evaluated is Viscoelastic Damper (VCD) and Rotational Friction Damper (RFD), with study case of a 15-story reinforced concrete apartment building with a dual system (column-beam and shear walls). The analysis used is a nonlinear time history analysis with 11 pairs of ground motions matched to the Indonesian response spectrum based on ASCE 41-17 and ASCE 7-16. In this analysis, each damper will be varied with a different position, namely the first model, the damper will be installed on the entire floor and in the second model, the damper will be installed on the 5th floor to the 9th floor, which is the floor with the largest drift. The results show that the model using both dampers increases the level of structural performance both globally and locally in the building, which will reduce the level of damage to the structural elements. But between the two dampers, the coupling beam that uses RFD is more effective than using VCD in improving building performance. The damper on the coupling beam has a good role in dissipating earthquakes and also in terms of ease of installation.Keywords: building, coupling beam, damper, nonlinear time history analysis
Procedia PDF Downloads 1726261 Pigging Operation in Two-Phase Flow Pipeline- Empirical and Simulation
Authors: Behnaz Jamshidi, Seyed Hassan Hashemabadi
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The main objective of this study is to investigate on pigging operation of two phase flow pipeline and compare the empirical and simulation results for 108 km long , 0.7934 mm (32 inches) diameter sea line of "Phase 1 South Pars Gas Complex", located in south of Iran. The pigging time, pig velocity, the amount of slug and slug catcher pressure were calculated and monitored closely as the key parameters. Simulation was done by "OLGA" dynamic simulation software and obtained results were compared and validated with empirical data in real operation. The relative errors between empirical data and simulation of the process were 3 % and 9 % for pigging time and accumulated slug volume respectively. Simulated pig velocity and changes of slug catcher pressure were consistent with real values, too. It was also found the slug catcher and condensate stabilization units have been adequately sized for gas-liquid separation and handle the slug batch during transient conditions such as pigging and start up.Keywords: sea line, pigging, slug catcher, two-phase flow, dynamic simulation
Procedia PDF Downloads 5076260 Indian Business-Papers in Industrial Revolution 4.0: A Paradigm Shift
Authors: Disha Batra
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The Industrial Revolution 4.0 is quite different, and a paradigm shift is underway in the media industry. With the advent of automated journalism and social media platforms, newspaper organizations have changed the way news was gathered and reported. The emergence of the fourth industrial revolution in the early 21st century has made the newspapers to adapt the changing technologies to remain relevant. This paper investigates the content of Indian business-papers in the era of the fourth industrial revolution and how these organizations have emerged in the time of convergence. The study is the content analyses of the top three Indian business dailies as per IRS (Indian Readership Survey) 2017 over a decade. The parametric analysis of the different parameters (source of information, use of illustrations, advertisements, layout, and framing, etc.) have been done in order to come across with the distinct adaptations and modifications by these dailies. The paper significantly dwells upon the thematic analysis of these newspapers in order to explore and find out the coverage given to various sub-themes of EBF (economic, business, and financial) journalism. Further, this study reveals the effect of high-speed algorithm-based trading, the aftermath of the fourth industrial revolution on the creative and investigative aspect of delivering financial stories by these respective newspapers. The study indicates a change heading towards an ongoing paradigm shift in the business newspaper industry with an adequate change in the source of information gathering along with the subtle increase in the coverage of financial news stories over the time.Keywords: business-papers, business news, financial news, industrial revolution 4.0.
Procedia PDF Downloads 1156259 Study on Heat Transfer Capacity Limits of Heat Pipe with Working Fluids Ammonia and Water
Authors: M. Heydari, A. Ghanami
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Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section. In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region, and evaporator. Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.used in the abstract.Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits
Procedia PDF Downloads 3996258 A Mathematical Model of Power System State Estimation for Power Flow Solution
Authors: F. Benhamida, A. Graa, L. Benameur, I. Ziane
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The state estimation of the electrical power system operation state is very important for supervising task. With the nonlinearity of the AC power flow model, the state estimation problem (SEP) is a nonlinear mathematical problem with many local optima. This paper treat the mathematical model for the SEP and the monitoring of the nonlinear systems of great dimensions with an application on power electrical system, the modelling, the analysis and state estimation synthesis in order to supervise the power system behavior. in fact, it is very difficult, to see impossible, (for reasons of accessibility, techniques and/or of cost) to measure the excessive number of the variables of state in a large-sized system. It is thus important to develop software sensors being able to produce a reliable estimate of the variables necessary for the diagnosis and also for the control.Keywords: power system, state estimation, robustness, observability
Procedia PDF Downloads 5236257 Hyperspectral Imaging and Nonlinear Fukunaga-Koontz Transform Based Food Inspection
Authors: Hamidullah Binol, Abdullah Bal
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Nowadays, food safety is a great public concern; therefore, robust and effective techniques are required for detecting the safety situation of goods. Hyperspectral Imaging (HSI) is an attractive material for researchers to inspect food quality and safety estimation such as meat quality assessment, automated poultry carcass inspection, quality evaluation of fish, bruise detection of apples, quality analysis and grading of citrus fruits, bruise detection of strawberry, visualization of sugar distribution of melons, measuring ripening of tomatoes, defect detection of pickling cucumber, and classification of wheat kernels. HSI can be used to concurrently collect large amounts of spatial and spectral data on the objects being observed. This technique yields with exceptional detection skills, which otherwise cannot be achieved with either imaging or spectroscopy alone. This paper presents a nonlinear technique based on kernel Fukunaga-Koontz transform (KFKT) for detection of fat content in ground meat using HSI. The KFKT which is the nonlinear version of FKT is one of the most effective techniques for solving problems involving two-pattern nature. The conventional FKT method has been improved with kernel machines for increasing the nonlinear discrimination ability and capturing higher order of statistics of data. The proposed approach in this paper aims to segment the fat content of the ground meat by regarding the fat as target class which is tried to be separated from the remaining classes (as clutter). We have applied the KFKT on visible and nearinfrared (VNIR) hyperspectral images of ground meat to determine fat percentage. The experimental studies indicate that the proposed technique produces high detection performance for fat ratio in ground meat.Keywords: food (ground meat) inspection, Fukunaga-Koontz transform, hyperspectral imaging, kernel methods
Procedia PDF Downloads 4316256 Modeling SET Effect on Charge Pump Phase Locked Loop
Authors: Varsha Prasad, S. Sandya
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Cosmic Ray effects in microelectronics such as single event effect (SET) and total dose ionization (TID) have been of major concern in space electronics since 1970. Advanced CMOS technologies have demonstrated reduced sensitivity to TID effect. However, charge pump Phase Locked Loop is very much vulnerable to single event transient effect. This paper presents an SET analysis model, where the SET is modeled as a double exponential pulse. The time domain analysis reveals that the settling time of the voltage controlled oscillator (VCO) depends on the SET pulse strength, setting the time constant and the damping factor. The analysis of the proposed SET analysis model is confirmed by the simulation results.Keywords: charge pump, phase locked loop, SET, VCO
Procedia PDF Downloads 4336255 Speciation Analysis by Solid-Phase Microextraction and Application to Atrazine
Authors: K. Benhabib, X. Pierens, V-D Nguyen, G. Mimanne
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The main hypothesis of the dynamics of solid phase microextraction (SPME) is that steady-state mass transfer is respected throughout the SPME extraction process. It considers steady-state diffusion is established in the two phases and fast exchange of the analyte at the solid phase film/water interface. An improved model is proposed in this paper to handle with the situation when the analyte (atrazine) is in contact with colloid suspensions (carboxylate latex in aqueous solution). A mathematical solution is obtained by substituting the diffusion coefficient by the mean of diffusion coefficient between analyte and carboxylate latex, and also thickness layer by the mean thickness in aqueous solution. This solution provides an equation relating the extracted amount of the analyte to the extraction a little more complicated than previous models. It also gives a better description of experimental observations. Moreover, the rate constant of analyte obtained is in satisfactory agreement with that obtained from the initial curve fitting.Keywords: pesticide, solid-phase microextraction (SPME) methods, steady state, analytical model
Procedia PDF Downloads 4876254 Dehydration of Glycerol to Acrolein with Solid Acid Catalysts
Authors: Lin Huang, Bo Wang, Armando Borgna
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Dehydration of glycerol to acrolein was conducted with solid acid catalysts in liquid phase in a batch reactor and in gas phase in a fix-bed reactor, respectively. In the liquid-phase reaction, ZSM-5, H3PO4-modified ZSM-5 and heteropolyacids including H3PW12O40•xH2O (HPW) and Cs2.5H0.5PW12O40 (CsPW) were studied as catalysts. High temperatures and high boiling point solvents such as sulfolane improved the selectivity to acrolein through suppressing the formation of polyglycerols and coke. Catalytic results and temperature-programmed desorption of ammonia showed that the yield of acrolein increased with increasing catalyst acidity within the range of weak acid strength. Weak acid sites favored the selectivity to acrolein whereas strong acid sites promoted the formation of coke. ZSM-5 possessing only acid sites led to a high acrolein yield, while heteropolyacid catalysts with strong acid sites produced a low acrolein yield. In the gas-phase reaction, HPW and CsPW supported on metal oxides such as SiO2, γ-Al2O3, SiO2-Al2O3, ZrO2 and silicate TUD-1 were studied as catalysts. HPW/TUD-1 was most active for the production of acrolein, followed by HPW/SiO2. An acrolein yield of 61 % was obtained over HPW/TUD-1. X-ray diffraction study suggested that HPW and CsPW were stable and more dispersed on SiO2, silicate TUD-1 and SiO2-Al2O3. It was found that the structures of HPW and CsPW were destroyed by interaction with γ-Al2O3 and ZrO2. Compared to CsPW/TUD-1, the higher acrolein yield with HPW/TUD-1 may be attributed to more Brønsted acid sites on HPW/TUD-1, based on preliminary pyridine adsorption IR study.Keywords: dehydration, glycerol, acrolein, solid acid catalysts, gas-phase, liquid-phase
Procedia PDF Downloads 2656253 Modeling and Control of a 4DoF Robotic Assistive Device for Hand Rehabilitation
Authors: Christopher Spiewak, M. R. Islam, Mohammad Arifur Rahaman, Mohammad H. Rahman, Roger Smith, Maarouf Saad
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For those who have lost the ability to move their hand, going through repetitious motions with the assistance of a therapist is the main method of recovery. We have been developed a robotic assistive device to rehabilitate the hand motions in place of the traditional therapy. The developed assistive device (RAD-HR) is comprised of four degrees of freedom enabling basic movements, hand function, and assists in supporting the hand during rehabilitation. We used a nonlinear computed torque control technique to control the RAD-HR. The accuracy of the controller was evaluated in simulations (MATLAB/Simulink environment). To see the robustness of the controller external disturbance as modelling uncertainty (±10% of joint torques) were added in each joints.Keywords: biorobotics, rehabilitation, robotic assistive device, exoskeleton, nonlinear control
Procedia PDF Downloads 4796252 A Two-Phase Flow Interface Tracking Algorithm Using a Fully Coupled Pressure-Based Finite Volume Method
Authors: Shidvash Vakilipour, Scott Ormiston, Masoud Mohammadi, Rouzbeh Riazi, Kimia Amiri, Sahar Barati
Abstract:
Two-phase and multi-phase flows are common flow types in fluid mechanics engineering. Among the basic and applied problems of these flow types, two-phase parallel flow is the one that two immiscible fluids flow in the vicinity of each other. In this type of flow, fluid properties (e.g. density, viscosity, and temperature) are different at the two sides of the interface of the two fluids. The most challenging part of the numerical simulation of two-phase flow is to determine the location of interface accurately. In the present work, a coupled interface tracking algorithm is developed based on Arbitrary Lagrangian-Eulerian (ALE) approach using a cell-centered, pressure-based, coupled solver. To validate this algorithm, an analytical solution for fully developed two-phase flow in presence of gravity is derived, and then, the results of the numerical simulation of this flow are compared with analytical solution at various flow conditions. The results of the simulations show good accuracy of the algorithm despite using a nearly coarse and uniform grid. Temporal variations of interface profile toward the steady-state solution show that a greater difference between fluids properties (especially dynamic viscosity) will result in larger traveling waves. Gravity effect studies also show that favorable gravity will result in a reduction of heavier fluid thickness and adverse gravity leads to increasing it with respect to the zero gravity condition. However, the magnitude of variation in favorable gravity is much more than adverse gravity.Keywords: coupled solver, gravitational force, interface tracking, Reynolds number to Froude number, two-phase flow
Procedia PDF Downloads 3156251 War and the Battle of Lebanese Television over Gender
Authors: Natalie M. Khazaal
Abstract:
The effects of the civil war on Lebanese women have been challenging to conceptualize. For some, war is a liberating and empowering force for women, while for others it is one that subjugates women and disempowers them in new ways. Scholars have explored the impact on the Lebanese civil war (1975-1990) on women in the fields of labor history, political activism and literary production. In all these arenas, women’s role and visibility were contested and negotiated in diverse ways. But probably the most visible arena where this contestation took place was television. Dramatized entertainment series were crucial sites where fictional women battled out the gender question, and which reflected and participated in the negotiations of gender politics. Even more stunningly, actual television stations became part of this battle through the plots and portrayals of women that they created. The state-backed Tele-Liban (TL) peddled patriarchal articulations of gender that directly competed with the edgy vision of liberated, independent women on the pirate Lebanese Broadcasting Corporation (LBC). This presentation explores how LBC used gender to distinguish its brand against the retrograde TL programing. Television series are an important medium for creating, testing and reenacting gender politics. They are even more consequential in another way. They are the sites where a dramatic shift in the relationship between Arab television and Arab publics—from benign neglect of public concerns towards engagement with audiences—took place for the first time. As this shift is at the heart of why Arab media was seen as a participant in the Arab uprisings, it is important to explore the roots of the shift in the dramas and comedy series of the mid-1980s Lebanese television. This presentation argues that television battles over gender were consequential and need serious consideration as sites of unexpected meaning.Keywords: gender, Lebanon, television, war, women
Procedia PDF Downloads 637