Search results for: amplitude shift keying
1221 Bi-Axial Stress Effects on Barkhausen-Noise
Authors: G. Balogh, I. A. Szabó, P.Z. Kovács
Abstract:
Mechanical stress has a strong effect on the magnitude of the Barkhausen-noise in structural steels. Because the measurements are performed at the surface of the material, for a sample sheet, the full effect can be described by a biaxial stress field. The measured Barkhausen-noise is dependent on the orientation of the exciting magnetic field relative to the axis of the stress tensor. The sample inhomogenities including the residual stress also modifies the angular dependence of the measured Barkhausen-noise. We have developed a laboratory device with a cross like specimen for bi-axial bending. The measuring head allowed performing excitations in two orthogonal directions. We could excite the two directions independently or simultaneously with different amplitudes. The simultaneous excitation of the two coils could be performed in phase or with a 90 degree phase shift. In principle this allows to measure the Barkhausen-noise at an arbitrary direction without moving the head, or to measure the Barkhausen-noise induced by a rotating magnetic field if a linear superposition of the two fields can be assumed.Keywords: Barkhausen-noise, bi-axial stress, stress measuring, stress dependency
Procedia PDF Downloads 2961220 Adopting English as a Language of Instruction of STEM in Tunisian Higher Education Institutions: Promises and Challenges
Authors: Mimoun Melliti
Abstract:
This research paper investigates the promises, challenges, and perspectives associated with teaching STEM subjects in English within Tunisian higher education institutions. The study explores the potential benefits of English-medium instruction in Science, Technology, Engineering, and Mathematics (henceforth STEM) education, with a special focus on enhanced global competitiveness, improved English language proficiency, and increased access to international resources and collaborations. Additionally, it examines the various challenges faced by educators and students, such as language shift/barriers, curriculum adaptation, faculty training, and student support. Through a comprehensive analysis of promises and challenges, this paper aims to provide insights and recommendations for effectively implementing English medium instruction (henceforth EMI) of STEM in Tunisian higher education institutions. The paper concludes with a recommended action plan for the proper introduction of EMI of STEM in Tunisia.Keywords: EMI;, STEM education, EFL, language reforms
Procedia PDF Downloads 761219 Detection of Nanotoxic Material Using DNA Based QCM
Authors: Juneseok You, Chanho Park, Kuehwan Jang, Sungsoo Na
Abstract:
Sensing of nanotoxic materials is strongly important, as their engineering applications are growing recently and results in that nanotoxic material can harmfully influence human health and environment. In current study we report the quartz crystal microbalance (QCM)-based, in situ and real-time sensing of nanotoxic-material by frequency shift. We propose the in situ detection of nanotoxic material of zinc oxice by using QCM functionalized with a taget-specific DNA. Since the mass of a target material is comparable to that of an atom, the mass change caused by target binding to DNA on the quartz electrode is so small that it is practically difficult to detect the ions at low concentrations. In our study, we have demonstrated the in-situ and fast detection of zinc oxide using the quartz crystal microbalance (QCM). The detection was derived from the DNA hybridization between the DNA on the quartz electrode. The results suggest that QCM-based detection opens a new avenue for the development of a practical water-testing sensor.Keywords: nanotoxic material, qcm, frequency, in situ sensing
Procedia PDF Downloads 4221218 Algorithmic Obligations: Proactive Liability for AI-Generated Content and Copyright Compliance
Authors: Aleksandra Czubek
Abstract:
As AI systems increasingly shape content creation, existing copyright frameworks face significant challenges in determining liability for AI-generated outputs. Current legal discussions largely focus on who bears responsibility for infringing works, be it developers, users, or entities benefiting from AI outputs. This paper introduces a novel concept of algorithmic obligations, proposing that AI developers be subject to proactive duties that ensure their models prevent copyright infringement before it occurs. Building on principles of obligations law traditionally applied to human actors, the paper suggests a shift from reactive enforcement to proactive legal requirements. AI developers would be legally mandated to incorporate copyright-aware mechanisms within their systems, turning optional safeguards into enforceable standards. These obligations could vary in implementation across international, EU, UK, and U.S. legal frameworks, creating a multi-jurisdictional approach to copyright compliance. This paper explores how the EU’s existing copyright framework, exemplified by the Copyright Directive (2019/790), could evolve to impose a duty of foresight on AI developers, compelling them to embed mechanisms that prevent infringing outputs. By drawing parallels to GDPR’s “data protection by design,” a similar principle could be applied to copyright law, where AI models are designed to minimize copyright risks. In the UK, post-Brexit text and data mining exemptions are seen as pro-innovation but pose risks to copyright protections. This paper proposes a balanced approach, introducing algorithmic obligations to complement these exemptions. AI systems benefiting from text and data mining provisions should integrate safeguards that flag potential copyright violations in real time, ensuring both innovation and protection. In the U.S., where copyright law focuses on human-centric works, this paper suggests an evolution toward algorithmic due diligence. AI developers would have a duty similar to product liability, ensuring that their systems do not produce infringing outputs, even if the outputs themselves cannot be copyrighted. This framework introduces a shift from post-infringement remedies to preventive legal structures, where developers actively mitigate risks. The paper also breaks new ground by addressing obligations surrounding the training data of large language models (LLMs). Currently, training data is often treated under exceptions such as the EU’s text and data mining provisions or U.S. fair use. However, this paper proposes a proactive framework where developers are obligated to verify and document the legal status of their training data, ensuring it is licensed or otherwise cleared for use. In conclusion, this paper advocates for an obligations-centered model that shifts AI-related copyright law from reactive litigation to proactive design. By holding AI developers to a heightened standard of care, this approach aims to prevent infringement at its source, addressing both the outputs of AI systems and the training processes that underlie them.Keywords: ip, technology, copyright, data, infringement, comparative analysis
Procedia PDF Downloads 181217 Comparative Study of Al₂O₃ and HfO₂ as Gate Dielectric on AlGaN/GaN Metal Oxide Semiconductor High-Electron Mobility Transistors
Authors: Kaivan Karami, Sahalu Hassan, Sanna Taking, Afesome Ofiare, Aniket Dhongde, Abdullah Al-Khalidi, Edward Wasige
Abstract:
We have made a comparative study on the influence of Al₂O₃ and HfO₂ grown using atomic layer deposition (ALD) technique as dielectric in the AlGaN/GaN metal oxide semiconductor high electron mobility transistor (MOS-HEMT) structure. Five samples consisting of 20 nm and 10 nm each of Al₂O₃ and HfO₂ respectively and a Schottky gate HEMT, were fabricated and measured. The threshold voltage shifts towards negative by 0.1 V and 1.8 V for 10 nm thick HfO2 and 10 nm thick Al₂O₃ gate dielectric layers respectively. The negative shift for the 20 nm HfO2 and 20 nm Al₂O₃ were 1.2 V and 4.9 V respectively. Higher gm/IDS (transconductance to drain current) ratio was also obtained in HfO₂ than Al₂O₃. With both materials as dielectric, a significant reduction in the gate leakage current in the order of 10^4 was obtained compared to the sample without the dielectric material.Keywords: AlGaN/GaN HEMTs, Al2O3, HfO2, MOSHEMTs.
Procedia PDF Downloads 1041216 Vertical and Lateral Vibration Response for Corrugated Track Curves Supported on High-Density Polyethylene and Hytrel Rail Pads
Authors: B.M. Balekwa, D.V.V. Kallon, D.J. Fourie
Abstract:
Modal analysis is applied to establish the dynamic difference between vibration response of the rails supported on High Density Polyethylene (HDPE) and Hytrel/6358 rail pads. The experiment was conducted to obtain the results in the form of Frequency Response Functions (FRFs) in the vertical and lateral directions. Three antiresonance modes are seen in the vertical direction; one occurs at about 150 Hz when the rail resting on the Hytrel/6358 pad experiences a force mid-span. For the rail resting on this type of rail pad, no antiresonance occurs when the force is applied on the point of the rail that is resting on the pad and directly on top of a sleeper. The two antiresonance modes occur in a frequency range of 250 – 300 Hz in the vertical direction for the rail resting on HDPE pads. At resonance, the rail vibrates with a higher amplitude, but at antiresonance, the rail transmits vibration downwards to the sleepers. When the rail is at antiresonance, the stiffness of the rail pads play a vital role in terms of damping the vertical vibration to protect the sleepers. From the FRFs it is understood that the Hytrel/6358 rail pads perform better than the HDPE in terms of vertical response, given that at a lower frequency range of 0 – 300 Hz only one antiresonance mode was identified for vertical vibration of the rail supported on Hytrel/6358. This means the rail is at antiresonance only once within this frequency range and this is the only time when vibration is transmitted downwards.Keywords: accelerance, FRF, rail corrugation, rail pad
Procedia PDF Downloads 1771215 Humanizing Industrial Architecture: When Form Meets Function and Emotion
Authors: Sahar Majed Asad
Abstract:
Industrial structures have historically focused on functionality and efficiency, often disregarding aesthetics and human experience. However, a new approach is emerging that prioritizes humanizing industrial architecture and creating spaces that promote well-being, sustainability, and social responsibility. This study explores the motivations and design strategies behind this shift towards more human-centered industrial environments, providing practical guidance for architects, designers, and other stakeholders interested in incorporating these principles into their work. Through in-depth interviews with architects, designers, and industry experts, as well as a review of relevant literature, this study uncovers the reasons for this change in industrial design. The findings reveal that this shift is driven by a desire to create environments that prioritize the needs and experiences of the people who use them. The study identifies strategies such as incorporating natural elements, flexible design, and advanced technologies as crucial in achieving human-centric industrial design. It also emphasizes that effective communication and collaboration among stakeholders are crucial for successful human-centered design outcomes. This paper provides a comprehensive analysis of the motivations and design strategies behind the humanization of industrial architecture. It begins by examining the history of industrial architecture and highlights the focus on functionality and efficiency. The paper then explores the emergence of human-centered design principles in industrial architecture, discussing the benefits of this approach, including creating more sustainable and socially responsible environments.The paper explains specific design strategies that prioritize the human experience of industrial spaces. It outlines how incorporating natural elements like greenery and natural lighting can create more visually appealing and comfortable environments for industrial workers. Flexible design solutions, such as movable walls and modular furniture, can make spaces more adaptable to changing needs and promote a sense of ownership and creativity among workers. Advanced technologies, such as sensors and automation, can improve the efficiency and safety of industrial spaces while also enhancing the human experience. To provide practical guidance, the paper offers recommendations for incorporating human-centered design principles into industrial structures. It emphasizes the importance of understanding the needs and experiences of the people who use these spaces and provides specific examples of how natural elements, flexible design, and advanced technologies can be incorporated into industrial structures to promote human well-being. In conclusion, this study demonstrates that the humanization of industrial architecture is a growing trend that offers tremendous potential for creating more sustainable and socially responsible built environments. By prioritizing the human experience of industrial spaces, designers can create environments that promote well-being, sustainability, and social responsibility. This research study provides practical guidance for architects, designers, and other stakeholders interested in incorporating human-centered design principles into their work, demonstrating that a human-centered approach can lead to functional and aesthetically pleasing industrial spaces that promote human well-being and contribute to a better future for all.Keywords: human-centered design, industrial architecture, sustainability, social responsibility
Procedia PDF Downloads 1611214 Schooling Culture in Egyptian Public Schools: Reform in Professional Development for Equity and hope in Education
Authors: Nora El-Bilawia
Abstract:
This paper discovers the challenges and/or opportunities to implementing multiple intelligence (MI) practices in English as foreign language (EFL) classrooms at Egyptian public schools as part of the government’s educational reform plan. It is found that Egyptian EFL teachers value the use of MI’s ways of teaching as means for active and higher order thinking. However, teachers believed they were underprivileged, as the government did not provide appropriate trainings, tools, or means to integrate MI in their daily lessons. They also conferred challenges they face due to some Egyptian schooling cultural practices. At the end of this chapter, a proposed need for a paradigm shift in the schooling culture in Egypt to implement practical changes in schools to promote hope in education such as the use of MI teaching tools. This study promotes cross-cultural understanding of educational opportunities and efforts for equal learning outcomes around the globe.Keywords: professional development, schooling culture, acculturation, equitable education
Procedia PDF Downloads 1011213 Gravitational Frequency Shifts for Photons and Particles
Authors: Jing-Gang Xie
Abstract:
The research, in this case, considers the integration of the Quantum Field Theory and the General Relativity Theory. As two successful models in explaining behaviors of particles, they are incompatible since they work at different masses and scales of energy, with the evidence that regards the description of black holes and universe formation. It is so considering previous efforts in merging the two theories, including the likes of the String Theory, Quantum Gravity models, and others. In a bid to prove an actionable experiment, the paper’s approach starts with the derivations of the existing theories at present. It goes on to test the derivations by applying the same initial assumptions, coupled with several deviations. The resulting equations get similar results to those of classical Newton model, quantum mechanics, and general relativity as long as conditions are normal. However, outcomes are different when conditions are extreme, specifically with no breakdowns even for less than Schwarzschild radius, or at Planck length cases. Even so, it proves the possibilities of integrating the two theories.Keywords: general relativity theory, particles, photons, Quantum Gravity Model, gravitational frequency shift
Procedia PDF Downloads 3591212 Dynamics Characterizations of Dielectric Electro- Active Polymer Pull Actuator for Vibration Control
Authors: Abdul Malek Abdul Wahab, Emiliano Rustighi
Abstract:
The elastomeric dielectric material has become a new alternative for actuator technology recently. The characteristic of dielectric elastomer that induces significant strain by applying voltage attracts the attention of many researchers to study this material in actuator technology. Thus, for a couple of years, Danfoss Ventures A/S has established their dielectric electro-active polymer (DEAP), which called Polypower. The main objective of this work was to investigate the characterization of PolyPower folded actuator as a ‘pull’ actuator for vibration control. A range of experiment was carried out on folded actuator including passive (without electrical stimulate) and active (with electrical stimulate) testing. For both categories static and dynamic testing have been done to determine the behavior of folded DEAP actuator. Voltage-Strain experiment determines that DEAP folded actuator is the non-linear system. The voltage supplied has no effect on the natural frequency which shows by ongoing dynamic testing. Finally, varies AC voltage with different amplitude and frequency has been provided to DEAP folded actuator. This experiment shows the parameter that influences the performance of DEAP folded actuator. As a result, the actuator performance dominated by the frequency dependence of the elastic response and was less influenced by dielectric properties.Keywords: elastomeric dielectric, dielectric electro-active polymer, folded actuator, voltage-strain
Procedia PDF Downloads 3191211 The Utilization of Particle Swarm Optimization Method to Solve Nurse Scheduling Problem
Authors: Norhayati Mohd Rasip, Abd. Samad Hasan Basari , Nuzulha Khilwani Ibrahim, Burairah Hussin
Abstract:
The allocation of working schedule especially for shift environment is hard to fulfill its fairness among them. In the case of nurse scheduling, to set up the working time table for them is time consuming and complicated, which consider many factors including rules, regulation and human factor. The scenario is more complicated since most nurses are women which have personnel constraints and maternity leave factors. The undesirable schedule can affect the nurse productivity, social life and the absenteeism can significantly as well affect patient's life. This paper aimed to enhance the scheduling process by utilizing the particle swarm optimization in order to solve nurse scheduling problem. The result shows that the generated multiple initial schedule is fulfilled the requirements and produces the lowest cost of constraint violation.Keywords: nurse scheduling, particle swarm optimisation, nurse rostering, hard and soft constraint
Procedia PDF Downloads 3721210 Self in Networks: Public Sphere in the Era of Globalisation
Authors: Sanghamitra Sadhu
Abstract:
A paradigm shift from capitalism to information technology is discerned in the era globalisation. The idea of public sphere, which was theorized in terms of its decline in the wake of the rise of commercial mass media has now emerged as a transnational or global sphere with the discourse being dominated by the ‘network society’. In other words, the dynamic of globalisation has brought about ‘a spatial turn’ in the social and political sciences which is also manifested in the public sphere, Especially the global public sphere. The paper revisits the Habermasian concept of the public sphere and focuses on the various social networking sites with their plausibility to create a virtual global public sphere. Situating Habermas’s notion of the bourgeois public sphere in the present context of global public sphere, it considers the changing dimensions of the public sphere across time and examines the concept of the ‘public’ with its shifting transformation from the concrete collective to the fluid ‘imagined’ category. The paper addresses the problematic of multimodal self-portraiture in the social networking sites as well as various online diaries/journals with an attempt to explore the nuances of the networked self.Keywords: globalisation, network society, public sphere, self-fashioning, identity, autonomy
Procedia PDF Downloads 4161209 Assesing Spatio-Temporal Growth of Kochi City Using Remote Sensing Data
Authors: Navya Saira George, Patroba Achola Odera
Abstract:
This study aims to determine spatio-temporal expansion of Kochi City, situated on the west coast of Kerala State in India. Remote sensing and GIS techniques have been used to determine land use/cover and urban expansion of the City. Classification of Landsat images of the years 1973, 1988, 2002 and 2018 have been used to reproduce a visual story of the growth of the City over a period of 45 years. Accuracy range of 0.79 ~ 0.86 is achieved with kappa coefficient range of 0.69 ~ 0.80. Results show that the areas covered by vegetation and water bodies decreased progressively from 53.0 ~ 30.1% and 34.1 ~ 26.2% respectively, while built-up areas increased steadily from 12.5 to 42.2% over the entire study period (1973 ~ 2018). The shift in land use from agriculture to non-agriculture may be attributed to the land reforms since 1980s.Keywords: Geographical Information Systems, Kochi City, Land use/cover, Remote Sensing, Urban Sprawl
Procedia PDF Downloads 1291208 Analysing the Permanent Deformation of Cohesive Subsoil Subject to Long Term Cyclic Train Loading
Authors: Natalie M. Wride, Xueyu Geng
Abstract:
Subgrade soils of railway infrastructure are subjected to a significant number of load applications over their design life. The use of slab track on existing and future proposed rail links requires a reduced maintenance and repair regime for the embankment subgrade, due to restricted access to the subgrade soils for remediation caused by cyclic deformation. It is, therefore, important to study the deformation behaviour of soft cohesive subsoils induced as a result of long term cyclic loading. In this study, a series of oedometer tests and cyclic triaxial tests (10,000 cycles) have been undertaken to investigate the undrained deformation behaviour of soft kaolin. X-ray Computer Tomography (CT) scanning of the samples has been performed to determine the change in porosity and soil structure density from the sample microstructure as a result of the laboratory testing regime undertaken. Combined with the examination of excess pore pressures and strains obtained from the cyclic triaxial tests, the results are compared with an existing analytical solution for long term settlement considering repeated low amplitude loading. Modifications to the analytical solution are presented based on the laboratory analysis that shows good agreement with further test data.Keywords: creep, cyclic loading, deformation, long term settlement, train loading
Procedia PDF Downloads 2991207 Joint Physical Custody: Lessons from the European Union
Authors: Katarzyna Kamińska
Abstract:
When thinking about custodial arrangements after divorce or separation, there has been a shift from sole custody, particularly maternal preference, to joint physical custody. In many Western countries, an increasing of children with separated parents have joint physical custody, which is believed to be in the best interests of the child, as children can maintain personal relations and direct contact with both parents on a regular basis. The aim of the article is to examine joint physical custody, both from the perspective of the binding legal instruments that are relevant to joint physical custody, the Principles of European Family Law drafted by the CEFL, as well as the international research on this matter. The thesis underlying this paper is that joint physical custody is in itself neither good nor bad, and it depends on how the arrangements are managed by the parents. The paper includes a reflection on joint physical custody in the face of the COVID-19 crisis. The results indicate that in normal circumstances, joint physical custody demands broad communication, and now it times of crisis, we need over-communication about children and plans. Only a very tight and coordinated co-parenting plan make the whole family safer.Keywords: joint physical custody, co-parenting, child welfare, COVID-19
Procedia PDF Downloads 2451206 Photoelectrochemical Study of Nanostructured Acropora-Like Lead Sulfide Thin Films
Authors: S. Kaci, A. Keffous, O. Fellahi, I. Bozetine, H. Menari
Abstract:
In this paper, we report the fabrication and characterization of Acropora-like lead sulfide nanostructured thin films using chemical bath deposition. The method has the strong points of low temperature and no surfactant, comparing with the other method. The preferential growth directions of the broad branches were indexed as along (200) directions. The photoelectrochemical property of the as-deposited thin films was also investigated. Photoelectrochemical characterization was performed in the aim to determine the flat band potential (Vfb) and to confirm the n-type character of PbS, elucidated from the J(V) curves both in the dark and under illumination. The apparition of the photocurrent Jph started at a potential VON of −0.41 V/ECS and increased towards the anodic direction, which is typical of n-type behavior. The near infrared absorbance spectrum displayed an absorbance edge at 1959 nm, showing blue shift comparing to bulk PbS (3020 nm). These nanostructured lead sulfide thin films may have potential application as dispersed photoelectrode capable of generating H2 under visible light.Keywords: lead sulfide, nanostructures, photo-conversion, thin films
Procedia PDF Downloads 3621205 X-Ray Dynamical Diffraction Rocking Curves in Case of Third Order Nonlinear Renninger Effect
Authors: Minas Balyan
Abstract:
In the third-order nonlinear Takagi’s equations for monochromatic waves and in the third-order nonlinear time-dependent dynamical diffraction equations for X-ray pulses for forbidden reflections the Fourier-coefficients of the linear and the third order nonlinear susceptibilities are zero. The dynamical diffraction in the nonlinear case is related to the presence in the nonlinear equations the terms proportional to the zero order and the second order nonzero Fourier coefficients of the third order nonlinear susceptibility. Thus in the third order nonlinear Bragg diffraction case a nonlinear analogue of the well known Renninger effect takes place. In this work, the ‘third order nonlinear Renninger effect’ is considered theoretically and numerically. If the reflection exactly is forbidden the diffracted wave’s amplitude is zero both in Laue and Bragg cases since the boundary conditions and dynamical diffraction equations are compatible with zero solution. But in real crystals due to some percent of dislocations and other localized defects, the atoms are displaced with respect to their equilibrium positions. Thus in real crystals susceptibilities of forbidden reflection are by some order small than for usual not forbidden reflections but are not exactly equal to zero. The numerical calculations for susceptibilities two order less than for not forbidden reflection show that in Bragg geometry case the nonlinear reflection curve’s behavior is the same as for not forbidden reflection, but for forbidden reflection the rocking curves’ width, center and boundaries are two order sensitive on the input intensity value. This gives an opportunity to investigate third order nonlinear X-ray dynamical diffraction for not intense beams – 0.001 in the units of critical intensity.Keywords: third order nonlinearity, Bragg diffraction, nonlinear Renninger effect, rocking curves
Procedia PDF Downloads 4061204 Analysis of Flow Dynamics of Heated and Cooled Pylon Upstream to the Cavity past Supersonic Flow with Wall Heating and Cooling
Authors: Vishnu Asokan, Zaid M. Paloba
Abstract:
Flow over cavities is an important area of research due to the significant change in flow physics caused by cavity aspect ratio, free stream Mach number and the nature of upstream boundary layer approaching the cavity leading edge. Cavity flow finds application in aircraft wheel well, weapons bay, combustion chamber of scramjet engines, etc. These flows are highly unsteady, compressible and turbulent and it involves mass entrainment coupled with acoustics phenomenon. Variation of flow dynamics in an angled cavity with a heated and cooled pylon upstream to the cavity with spatial combinations of heat flux addition and removal to the wall studied numerically. The goal of study is to investigate the effect of energy addition, removal to the cavity walls and pylon cavity flow dynamics. Preliminary steady state numerical simulations on inclined cavities with heat addition have shown that wall pressure profiles, as well as the recirculation, are influenced by heat transfer to the compressible fluid medium. Such a hybrid control of cavity flow dynamics in the form of heat transfer and pylon geometry can open out greater opportunities in enhancement of mixing and flame holding requirements of supersonic combustors. Addition of pylon upstream to the cavity reduces the acoustic oscillations emanating from the geometry. A numerical unsteady analysis of supersonic flow past cavities exposed to cavity wall heating and cooling with heated and cooled pylon helps to get a clear idea about the oscillation suppression in the cavity. A Cavity of L/D 4 and aft wall angle 22 degree with an upstream pylon of h/D=1.5 mm with a wall angle 29 degree exposed to supersonic flow of Mach number 2 and heat flux of 40 W/cm² and -40 W/cm² modeled for the above study. In the preliminary study, the domain is modeled and validated numerically with a turbulence model of SST k-ω using an HLLC implicit scheme. Both qualitative and quantitative flow data extracted and analyzed using advanced CFD tools. Flow visualization is done using numerical Schlieren method as the fluid medium gives the density variation. The heat flux addition to the wall increases the secondary vortex size of the cavity and removal of energy leads to the reduction in vortex size. The flow field turbulence seems to be increasing at higher heat flux. The shear layer thickness increases as heat flux increases. The steady state analysis of wall pressure shows that there is variation on wall pressure as heat flux increases. Shift in frequency of unsteady wall pressure analysis is an interesting observation for the above study. The time averaged skin friction seems to be reducing at higher heat flux due to the variation in viscosity of fluid inside the cavity.Keywords: energy addition, frequency shift, Numerical Schlieren, shear layer, vortex evolution
Procedia PDF Downloads 1431203 Investigating the Regulation System of the Synchronous Motor Excitation Mode Serving as a Reactive Power Source
Authors: Baghdasaryan Marinka, Ulikyan Azatuhi
Abstract:
The efficient usage of the compensation abilities of the electrical drive synchronous motors used in production processes can essentially improve the technical and economic indices of the process. Reducing the flows of the reactive electrical energy due to the compensation of reactive power allows to significantly reduce the load losses of power in the electrical networks. As a result of analyzing the scientific works devoted to the issues of regulating the excitation of the synchronous motors, the need for comprehensive investigation and estimation of the excitation mode has been substantiated. By means of the obtained transmission functions, in the Simulink environment of the software package MATLAB, the transition processes of the excitation mode have been studied. As a result of obtaining and estimating the graph of the Nyquist plot and the transient process, the necessity of developing the Proportional-Integral-Derivative (PID) regulator has been justified. The transient processes of the system of the PID regulator have been investigated, and the amplitude–phase characteristics of the system have been estimated. The analysis of the obtained results has shown that the regulation indices of the developed system have been improved. The developed system can be successfully applied for regulating the excitation voltage of different-power synchronous motors, operating with a changing load, ensuring a value of the power coefficient close to 1.Keywords: transition process, synchronous motor, excitation mode, regulator, reactive power
Procedia PDF Downloads 2351202 Electrical Cardiac Remodeling in Elite Athletes: A Comparative Study between Triathletes and Cyclists
Authors: Lingxia Li, Frédéric Schnell, Thibault Lachard, Anne-Charlotte Dupont, Shuzhe Ding, Solène Le Douairon Lahaye
Abstract:
Background: Repetitive participation in triathlon training results in significant myocardial changes. However, whether the cardiac remodeling in triathletes is related to the specificities of the sport (consisting of three sports) raises questions. Methods: Elite triathletes and cyclists registered on the French ministerial lists of high-level athletes were involved. The basic information and routine electrocardiogram records were obtained. Electrocardiograms were evaluated according to clinical criteria. Results: Of the 105 athletes included in the study, 42 were from the short-distance triathlon (40%), and 63 were from the road cycling (60%). The average age was 22.1±4.2 years. The P wave amplitude was significantly lower in triathletes than in cyclists (p=0.005), and no significant statistical difference was found in heart rate, RR interval, PR or PQ interval, QRS complex, QRS axe, QT interval, and QTc (p>0.05). All the measured parameters were within normal ranges. The most common electrical manifestations were early repolarization (60.95%) and incomplete right bundle branch block (43.81%); there was no statistical difference between the groups (p>0.05). Conclusions: Prolonged intensive endurance exercise training induces physiological cardiac remodeling in both triathletes and cyclists. The most common electrocardiogram manifestations were early repolarization and incomplete right bundle branch block.Keywords: cardiac screening, electrocardiogram, triathlon, cycling, elite athletes
Procedia PDF Downloads 41201 Perspectives of Renewable Energy in 21st Century in India: Statistics and Estimation
Authors: Manoj Kumar, Rajesh Kumar
Abstract:
With the favourable geographical conditions at Indian-subcontinent, it is suitable for flourishing renewable energy. Increasing amount of dependence on coal and other conventional sources is driving the world into pollution and depletion of resources. This paper presents the statistics of energy consumption and energy generation in Indian Sub-continent, which notifies us with the increasing energy demands surpassing energy generation. With the aggrandizement in demand for energy, usage of coal has increased, since the major portion of energy production in India is from thermal power plants. The increase in usage of thermal power plants causes pollution and depletion of reserves; hence, a paradigm shift to renewable sources is inevitable. In this work, the capacity and potential of renewable sources in India are analyzed. Based on the analysis of this work, future potential of these sources is estimated.Keywords: depletion of reserves, energy consumption and generation, emmissions, global warming, renewable sources
Procedia PDF Downloads 4321200 Cdk1 Gates Cell Cycle-Dependent tRNA Synthesis by Regulating RNA Polymerase III Activity
Authors: Maricarmen Herrera, Pierre Chymkowitch, Joe Robertson, Jens Eriksson, Jorrit Enserink
Abstract:
tRNA genes are transcribed by RNA polymerase III. During recent years, it has become clear that tDNA transcription fluctuates during the cell cycle. However, the mechanism by which the cell cycle controls the amplitude of tDNA transcription remains unknown. We found that the cyclin Clb5 recruits the cyclin dependent kinase Cdk1 to tRNA genes to sharply increase tRNA synthesis during a brief interval in the cell cycle. We show that Cdk1 promotes the interaction of TFIIIB with TFIIIC, that it stimulates the recruitment of TFIIIC to tRNA genes, that it prevents the formation of an overly stable TFIIIB-tDNA complex and that it augments the dynamics of RNA polymerase III. Furthermore, we identify Bdp1 as a novel Cdk1 substrate, and phosphorylation of Bdp1 is required for the cell cycle-dependent increase in tDNA transcription. In addition, we show that phosphorylation of the Cdk1 substrate Nup60 mediates formation of a Nup60-Nup2 complex at tRNA genes, which is also required for cell cycle-dependent tDNA transcription. Together, our findings indicate that Cdk1 activity gates tRNA synthesis by regulating the dynamics of the TFIIIB-TFIIIC-RNAPIII complex, and that it may promote the formation of a nuclear pore microenvironment conducive to efficient tDNA transcription.Keywords: Cdk1, cell cycle, RNAPIII machinery, tRNA
Procedia PDF Downloads 1811199 Exploring the Potential of Blockchain to Improve Higher Education
Authors: Tony Cripps, Larry Kimber
Abstract:
This paper will begin by briefly explaining how blockchain technology works. Then, after highlighting a few of the ways it promises to heavily impact all aspects of the digital landscape, the focus will shift to Blockchain in the field of education, with specific emphasis placed on practical applications in foreign language education. Blockchain is a decentralized Internet-based software application that guarantees truth in transactions. This means whenever two parties engage in a transaction using Blockchain, it is time-stamped, added to a block of other transactions, and then permanently attached to an unalterable ‘chain’ of blocks. The potential for developing applications with Blockchain is therefore immense, since software systems that ensure the impossibility of outside tampering are invaluable. Innovative ideas in every imaginable domain are presently being entertained and Blockchain in education is no exception. For instance, records kept within and between institutions of students’ grade performance, academic achievement and verification of assignment/course completion are just a few examples of how this new technology might potentially be used to revolutionize education. It is hoped that this paper will be of use to all educators interested in the application of technology in the field of education.Keywords: blockchain, disruption, potential, technology
Procedia PDF Downloads 1381198 A Detection Method of Faults in Railway Pantographs Based on Dynamic Phase Plots
Authors: G. Santamato, M. Solazzi, A. Frisoli
Abstract:
Systems for detection of damages in railway pantographs effectively reduce the cost of maintenance and improve time scheduling. In this paper, we present an approach to design a monitoring tool fitting strong customer requirements such as portability and ease of use. Pantograph has been modeled to estimate its dynamical properties, since no data are available. With the aim to focus on suspensions health, a two Degrees of Freedom (DOF) scheme has been adopted. Parameters have been calculated by means of analytical dynamics. A Finite Element Method (FEM) modal analysis verified the former model with an acceptable error. The detection strategy seeks phase-plots topology alteration, induced by defects. In order to test the suitability of the method, leakage in the dashpot was simulated on the lumped model. Results are interesting because changes in phase plots are more appreciable than frequency-shift. Further calculations as well as experimental tests will support future developments of this smart strategy.Keywords: pantograph models, phase plots, structural health monitoring, damage detection
Procedia PDF Downloads 3621197 Magnetic Survey for the Delineation of Concrete Pillars in Geotechnical Investigation for Site Characterization
Authors: Nuraddeen Usman, Khiruddin Abdullah, Mohd Nawawi, Amin Khalil Ismail
Abstract:
A magnetic survey is carried out in order to locate the remains of construction items, specifically concrete pillars. The conventional Euler deconvolution technique can perform the task but it requires the use of fixed structural index (SI) and the construction items are made of materials with different shapes which require different SI (unknown). A Euler deconvolution technique that estimate background, horizontal coordinate (xo and yo), depth and structural index (SI) simultaneously is prepared and used for this task. The synthetic model study carried indicated the new methodology can give a good estimate of location and does not depend on magnetic latitude. For field data, both the total magnetic field and gradiometer reading had been collected simultaneously. The computed vertical derivatives and gradiometer readings are compared and they have shown good correlation signifying the effectiveness of the method. The filtering is carried out using automated procedure, analytic signal and other traditional techniques. The clustered depth solutions coincided with the high amplitude/values of analytic signal and these are the possible target positions of the concrete pillars being sought. The targets under investigation are interpreted to be located at the depth between 2.8 to 9.4 meters. More follow up survey is recommended as this mark the preliminary stage of the work.Keywords: concrete pillar, magnetic survey, geotechnical investigation, Euler Deconvolution
Procedia PDF Downloads 2581196 Rurality in Flux: A Perspective on Changing Face of Rural Tourism Enterprise
Authors: Gunjan Saxena
Abstract:
This paper presents case insights from India and Mexico to illustrate how tourism can work as a tool for bringing about peace and prosperity in disadvantaged communities living in peripheral rural localities. A reordering of rural space, given the slow but definite shift from production-oriented activities towards more complex and contested blends of production, consumption and protection indicates clearly that rurality is in flux. Whilst on one hand, there is a predominance of urban interests in the countryside, on the other rurality is boxed and presented for consumption in urban localities. Qualitative data, collected using semi-structured interviews and participant observation, is used in illustrating how creative enterprise is bringing about innovative use of rural ethos and space in response to consumer demands. Overall, this work seeks to contribute to debates on how rurality no longer represents a fixed space of tradition, but is packaged and promoted in a multi-faceted manner to creatively perform for and access tourism markets.Keywords: rural tourism, creative enterprise, India, Mexico
Procedia PDF Downloads 3141195 Model Based Improvement of Ultrasound Assisted Transport of Cohesive Dry Powders
Authors: Paul Dunst, Ing. Tobias Hemsel, Ing. Habil. Walter Sextro
Abstract:
The use of fine powders with high cohesive and adhesive properties leads to challenges during transport, mixing and dosing in industrial processes, which have not been satisfactorily solved so far. Due to the increased contact forces at the transporting parts (e. g. pipe-wall and transport screws), conventional transport systems and also vibratory conveyors reach their limits. Often, flowability increasing additives that need to be removed again in later process steps are the only option to achieve wanted transport results. A rather new ultrasound-assisted powder transport system showed to overcome some of the issues by manipulating the effective friction between powder and transport pipe. Within this contribution, the transport mechanism will be introduced shortly, together with preliminary transport results. As the tangential force of the transport pipe and the powder is the main influencing factor within the transport process, a test stand for measuring tangential forces of a powder-wall contact in the presence of an ultrasonic vibration orthogonal to the contact plane was built. Measurements for a sample powder show that the effective tangential force can already be significantly reduced at very low ultrasonic amplitude. As a result of the measurements, an empirical model for the relationship of tangential force, contact parameters and ultrasonic excitation is presented. This model was used to adjust the driving parameters of the powder transport system, resulting in better performance.Keywords: powder transport, ultrasound, friction, friction manipulation, vibratory conveyor
Procedia PDF Downloads 1521194 A Micro-Scale of Electromechanical System Micro-Sensor Resonator Based on UNO-Microcontroller for Low Magnetic Field Detection
Authors: Waddah Abdelbagi Talha, Mohammed Abdullah Elmaleeh, John Ojur Dennis
Abstract:
This paper focuses on the simulation and implementation of a resonator micro-sensor for low magnetic field sensing based on a U-shaped cantilever and piezoresistive configuration, which works based on Lorentz force physical phenomena. The resonance frequency is an important parameter that depends upon the highest response and sensitivity through the frequency domain (frequency response) of any vibrated micro-scale of an electromechanical system (MEMS) device. And it is important to determine the direction of the detected magnetic field. The deflection of the cantilever is considered for vibrated mode with different frequencies in the range of (0 Hz to 7000 Hz); for the purpose of observing the frequency response. A simple electronic circuit-based polysilicon piezoresistors in Wheatstone's bridge configuration are used to transduce the response of the cantilever to electrical measurements at various voltages. Microcontroller-based Arduino program and PROTEUS electronic software are used to analyze the output signals from the sensor. The highest output voltage amplitude of about 4.7 mV is spotted at about 3 kHz of the frequency domain, indicating the highest sensitivity, which can be called resonant sensitivity. Based on the resonant frequency value, the mode of vibration is determined (up-down vibration), and based on that, the vector of the magnetic field is also determined.Keywords: resonant frequency, sensitivity, Wheatstone bridge, UNO-microcontroller
Procedia PDF Downloads 1271193 New Media and Its Role in Shaping the 'Bersih Movement' in Malaysia
Authors: Rosyidah Muhamad
Abstract:
New media is facilitating collective action in ways never thought possible. Although the broader political climate may have a powerful influence on the success or failure of emerging social movement organizations, the Internet is enabling groups previously incapable of political action to find their voices Whether this shift is offering greater relative benefit to previously underrepresented or incumbent political fixtures is subject to debate, but it is clear that like-minded people are now able to better locate and converse with each other via many Internet. The recent social movement in Malaysia – the BERSIH Movement had attracted demonstrators from countries all over the world. The movement with an unforeseen mixture of nationalities became world news. Interestingly, the new media seemed to play a crucial role in the organization of the protests around the world. This article maps this movement via an analysis of their websites. It examines the contribution of these websites based on the collective identity, actual mobilization and a network of organizations. This research indicates signs of an integration of different organizations that contributed to an important role of the new media.Keywords: Bersih Movement, Malaysian politics, new media, social movement
Procedia PDF Downloads 2781192 Heat Transfer Process Parameter Optimization in SI/Ge Using TAGUCHI Method
Authors: Evln Ranga Charyulu, S. P. Venu Madhavarao, S. Udaya kumar, S. V. S. S. N. V. G. Krishna Murthy
Abstract:
With the advent of new nanometer process technologies, it is possible to integrate billion transistors on a single substrate. When more and more functionality included there is the possibility of multi-million transistors switching simultaneously consuming more power and dissipating more power along with more leakage of current into the substrate of porous silicon or germanium material. These results in substrate heating and thermal noise generation coupled to signals of interest. The heating process is represented by coupled nonlinear partial differential equations in porous silicon and germanium. By identifying heat sources and heat fluxes may results in designing of ultra-low power circuits. The PDEs are solved by finite difference scheme assuming that boundary layer equations in porous silicon and germanium. Local heat fluxes along the vertical isothermal surface immersed in porous SI/Ge are considered. The parameters considered for optimization are thermal diffusivity, thermal expansion coefficient, thermal diffusion ratio, permeability, specific heat at constant temperatures, Rayleigh number, amplitude of wavy surface, mass expansion coefficient. The diffusion of heat was caused by the concentration gradient. Thermal physical properties are homogeneous and isotropic. By using L8, TAGUCHI method the parameters are optimized.Keywords: heat transfer, pde, taguchi optimization, SI/Ge
Procedia PDF Downloads 337