Search results for: Hannah E. Power
4435 Acoustic Energy Harvesting Using Polyvinylidene Fluoride (PVDF) and PVDF-ZnO Piezoelectric Polymer
Authors: S. M. Giripunje, Mohit Kumar
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Acoustic energy that exists in our everyday life and environment have been overlooked as a green energy that can be extracted, generated, and consumed without any significant negative impact to the environment. The harvested energy can be used to enable new technology like wireless sensor networks. Technological developments in the realization of truly autonomous MEMS devices and energy storage systems have made acoustic energy harvesting (AEH) an increasingly viable technology. AEH is the process of converting high and continuous acoustic waves from the environment into electrical energy by using an acoustic transducer or resonator. AEH is not popular as other types of energy harvesting methods since sound waves have lower energy density and such energy can only be harvested in very noisy environment. However, the energy requirements for certain applications are also correspondingly low and also there is a necessity to observe the noise to reduce noise pollution. So the ability to reclaim acoustic energy and store it in a usable electrical form enables a novel means of supplying power to relatively low power devices. A quarter-wavelength straight-tube acoustic resonator as an acoustic energy harvester is introduced with polyvinylidene fluoride (PVDF) and PVDF doped with ZnO nanoparticles, piezoelectric cantilever beams placed inside the resonator. When the resonator is excited by an incident acoustic wave at its first acoustic eigen frequency, an amplified acoustic resonant standing wave is developed inside the resonator. The acoustic pressure gradient of the amplified standing wave then drives the vibration motion of the PVDF piezoelectric beams, generating electricity due to the direct piezoelectric effect. In order to maximize the amount of the harvested energy, each PVDF and PVDF-ZnO piezoelectric beam has been designed to have the same structural eigen frequency as the acoustic eigen frequency of the resonator. With a single PVDF beam placed inside the resonator, the harvested voltage and power become the maximum near the resonator tube open inlet where the largest acoustic pressure gradient vibrates the PVDF beam. As the beam is moved to the resonator tube closed end, the voltage and power gradually decrease due to the decreased acoustic pressure gradient. Multiple piezoelectric beams PVDF and PVDF-ZnO have been placed inside the resonator with two different configurations: the aligned and zigzag configurations. With the zigzag configuration which has the more open path for acoustic air particle motions, the significant increases in the harvested voltage and power have been observed. Due to the interruption of acoustic air particle motion caused by the beams, it is found that placing PVDF beams near the closed tube end is not beneficial. The total output voltage of the piezoelectric beams increases linearly as the incident sound pressure increases. This study therefore reveals that the proposed technique used to harvest sound wave energy has great potential of converting free energy into useful energy.Keywords: acoustic energy, acoustic resonator, energy harvester, eigenfrequency, polyvinylidene fluoride (PVDF)
Procedia PDF Downloads 3854434 Social Freedom and Real Utopias: Making ‘Eroding Capitalism’ a Theme in Axel Honneth’s Theory of Socialism
Authors: Yotaro Natani
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In his recent works, Frankfurt School theorist Axel Honneth elucidates an intersubjective notion of social freedom and outlines a vision of socialism as the realization of social freedom in the family, market economy, and public sphere. These arguments are part of his broader project of defending the tradition of immanent critique and normative reconstruction. In contrast, American Marxist sociologist Erik Olin Wright spells out a vision of socialism in terms of building real utopias -democratic, egalitarian, alternative institutions- through the exercise of civil society’s social power over the economy and state. Wright identifies ‘eroding capitalism’ as the framework for thinking about the strategic logics of gradually diminishing the dominance of capitalism. Both thinkers envision the transition toward socialism in terms of democratic experimentation; Honneth is more attentive to the immanent norms of social life, whereas Wright is better aware of the power of antagonistic structures. This paper attempts to synthesize the ideas of Honneth and Wright. It will show that Honneth’s critique of capitalism suffers from certain ambiguities because he attributes normative legitimacy to existing institutions, resulting in arguments that do not problematize aspects of capitalist structures. This paper will argue that incorporating the notion of power and thematizing the erosion of capitalism as a long-term goal for socialist change will allow Honneth to think more precisely about the conditions for realizing social freedom, in a manner that is still consistent with the immanent critique tradition. Such reformulation will result in a concept of social freedom that is less static and rooted in functional teleology and more oriented toward creative agency and experimental democracy.Keywords: Axel Honneth, immanent critique, real utopias, social freedom, socialism
Procedia PDF Downloads 1454433 Digital Signal Processor Implementation of a Novel Sinusoidal Pulse Width Modulation Algorithm Algorithm for a Reduced Delta Inverter
Authors: Asma Ben Rhouma, Mahmoud Hamouda
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The delta inverter is considered as the reduced three-phase dc/ac converter topology. It contains only three two-quadrant power switches compared to six in the conventional one. This reduced power conversion topology is widely considered in many industrial applications, such as electric traction and large photovoltaic systems. This paper is focused on a new sinusoidal pulse width modulation algorithm (SPWM) developed for the delta inverter. As an unconventional inverter’s structure, irregular modulating functions waveforms of the SPWM switching technique are generated. The performances of the proposed SPWM technique was proven through computer simulations carried out on a delta inverter feeding a three-phase RL load. Digital Signal Processor (DSP) implementation of the novel SPWM algorithm have been realized on a laboratory prototype of the delta inverter feeding an RL load and a squirrel cage induction motor. Experimental results have highlighted its high performances under the proposed SPWM method.Keywords: delta inverter, SPWM, simulation, DSP implementation
Procedia PDF Downloads 1644432 Hydrodynamic Analysis on the Body of a Solar Autonomous Underwater Vehicle by Numerical Method
Authors: Mohammad Moonesun, Ehsan Asadi Asrami, Julia Bodnarchuk
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In the case of Solar Autonomous Underwater Vehicle, which uses photovoltaic panels to provide its required power, due to limitation of energy, accurate estimation of resistance and energy has major sensitivity. In this work, hydrodynamic calculations by numerical method for a solar autonomous underwater vehicle equipped by two 50 W photovoltaic panels has been studied. To evaluate the required power and energy, hull hydrodynamic resistance in several velocities should be taken into account. To do this assessment, the ANSYS FLUENT 18 applied as Computational Fluid Dynamics (CFD) tool that solves Reynolds Average Navier Stokes (RANS) equations around AUV hull, and K-ω SST is used as turbulence model. To validate of solution method and modeling approach, the model of Myring submarine that it’s experimental data was available, is simulated. There is good agreement between numerical and experimental results. Also, these results showed that the K-ω SST Turbulence model is an ideal method to simulate the AUV motion in low velocities.Keywords: underwater vehicle, hydrodynamic resistance, numerical modelling, CFD, RANS
Procedia PDF Downloads 2054431 Visualization Tool for EEG Signal Segmentation
Authors: Sweeti, Anoop Kant Godiyal, Neha Singh, Sneh Anand, B. K. Panigrahi, Jayasree Santhosh
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This work is about developing a tool for visualization and segmentation of Electroencephalograph (EEG) signals based on frequency domain features. Change in the frequency domain characteristics are correlated with change in mental state of the subject under study. Proposed algorithm provides a way to represent the change in the mental states using the different frequency band powers in form of segmented EEG signal. Many segmentation algorithms have been suggested in literature having application in brain computer interface, epilepsy and cognition studies that have been used for data classification. But the proposed method focusses mainly on the better presentation of signal and that’s why it could be a good utilization tool for clinician. Algorithm performs the basic filtering using band pass and notch filters in the range of 0.1-45 Hz. Advanced filtering is then performed by principal component analysis and wavelet transform based de-noising method. Frequency domain features are used for segmentation; considering the fact that the spectrum power of different frequency bands describes the mental state of the subject. Two sliding windows are further used for segmentation; one provides the time scale and other assigns the segmentation rule. The segmented data is displayed second by second successively with different color codes. Segment’s length can be selected as per need of the objective. Proposed algorithm has been tested on the EEG data set obtained from University of California in San Diego’s online data repository. Proposed tool gives a better visualization of the signal in form of segmented epochs of desired length representing the power spectrum variation in data. The algorithm is designed in such a way that it takes the data points with respect to the sampling frequency for each time frame and so it can be improved to use in real time visualization with desired epoch length.Keywords: de-noising, multi-channel data, PCA, power spectra, segmentation
Procedia PDF Downloads 3974430 Impact of Social Media on the Functioning of the Indian Government: A Critical Analysis
Authors: Priya Sepaha
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Social media has loomed as the most effective tool in recent times to flag the causes, contents, opinions and direction of any social movement and has demonstrated that it will have a far-reaching effect on government as well. This study focuses on India which has emerged as the fastest growing community on social media. Social movement activists, in particular, have extensively utilized the power of digital social media to streamline the effectiveness of social protest on a particular issue through extensive successful mass mobilizations. This research analyses the role and impact of social media as a power to catalyze the social movements in India and further seeks to describe how certain social movements are resisted, subverted, co-opted and/or deployed by social media. The impact assessment study has been made with the help of cases, policies and some social movement which India has witnessed the assertion of numerous social issues perturbing the public which eventually paved the way for remarkable judicial decisions. The paper concludes with the observations that despite its pros and cons, the impacts of social media on the functioning of the Indian Government have demonstrated that it has already become an indispensable tool in the hands of social media-suave Indians who are committed to bring about a desired change.Keywords: social media, social movements, impact, law, government
Procedia PDF Downloads 1614429 Switching of Series-Parallel Connected Modules in an Array for Partially Shaded Conditions in a Pollution Intensive Area Using High Powered MOSFETs
Authors: Osamede Asowata, Christo Pienaar, Johan Bekker
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Photovoltaic (PV) modules may become a trend for future PV systems because of their greater flexibility in distributed system expansion, easier installation due to their nature, and higher system-level energy harnessing capabilities under shaded or PV manufacturing mismatch conditions. This is as compared to the single or multi-string inverters. Novel residential scale PV arrays are commonly connected to the grid by a single DC–AC inverter connected to a series, parallel or series-parallel string of PV panels, or many small DC–AC inverters which connect one or two panels directly to the AC grid. With an increasing worldwide interest in sustainable energy production and use, there is renewed focus on the power electronic converter interface for DC energy sources. Three specific examples of such DC energy sources that will have a role in distributed generation and sustainable energy systems are the photovoltaic (PV) panel, the fuel cell stack, and batteries of various chemistries. A high-efficiency inverter using Metal Oxide Semiconductor Field-Effect Transistors (MOSFETs) for all active switches is presented for a non-isolated photovoltaic and AC-module applications. The proposed configuration features a high efficiency over a wide load range, low ground leakage current and low-output AC-current distortion with no need for split capacitors. The detailed power stage operating principles, pulse width modulation scheme, multilevel bootstrap power supply, and integrated gate drivers for the proposed inverter is described. Experimental results of a hardware prototype, show that not only are MOSFET efficient in the system, it also shows that the ground leakage current issues are alleviated in the proposed inverter and also a 98 % maximum associated driver circuit is achieved. This, in turn, provides the need for a possible photovoltaic panel switching technique. This will help to reduce the effect of cloud movements as well as improve the overall efficiency of the system.Keywords: grid connected photovoltaic (PV), Matlab efficiency simulation, maximum power point tracking (MPPT), module integrated converters (MICs), multilevel converter, series connected converter
Procedia PDF Downloads 1274428 Obtaining the Analytic Dependence for Estimating the Ore Mill Operation Modes
Authors: Baghdasaryan Marinka
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The particular significance of comprehensive estimation of the increase in the operation efficiency of the mill motor electromechanical system, providing the main technological process for obtaining a metallic concentrate, as well as the technical state of the system are substantiated. The works carried out in the sphere of investigating, creating, and improving the operation modes of electric drive motors and ore-grinding mills have been studied. Analytic dependences for estimating the operation modes of the ore-grinding mills aimed at improving the ore-crashing process maintenance and technical service efficiencies have been obtained. The obtained analytic dependencies establish a link between the technological and power parameters of the electromechanical system, and allow to estimate the state of the system and reveal the controlled parameters required for the efficient management in case of changing the technological parameters. It has been substantiated that the changes in the technological factors affecting the consumption power of the drive motor do not cause an instability in the electromechanical system.Keywords: electromechanical system, estimation, operation mode, productivity, technological process, the mill filling degree
Procedia PDF Downloads 2704427 Dynamics of Follicle Vascular Perfusion, Dimensions, Antrum Growth, Circulating Angiogenic Mediators from Deviation to Ovulation
Authors: Elshymaa A. Abdelnaby, Amal M. Abo El-Maaty
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This study aimed to investigate dynamics of dominant and subordinate follicles change in dimensions, vascularity and angiogenic hormones after completing deviation till ovulation. Five cyclic mares were subjected to daily blood sampling and rectal Doppler ultrasonographic examination along two estrous cycles. Using electronic calipers, three diameters were recorded for each follicle to estimate area and volume. Leptin, Insulin-like growth factor-I (IGF-1), nitric oxide (NO) and estradiol (E2) were measured. Area of color- and power- Doppler modes with area and circumference of the first (preovulatory) and subordinate follicles were measured in pixels. Follicles were classified into F1O (preovulatory), F2O (subordinate), F3O (third ovulatory) on the dominant ovary and F1C (first contra) and F2C (second contra) on the contralateral ovary. Days before ovulation significantly (P < 0.0001) affected diameter, circumference, area, volume, area/pixel and antrum area of the preovulatory follicle. With the increase of diameter, area, volume area/pixel, antrum area/pixel and circumference of F1O, those of all subordinates were decreasing. The blue blood flow area, power and power minus red blood flow area of F1O increased from day -6 till day of ovulation (day 0), but red blood flow area significantly decreased. F1O had the lowest percent of colored pixels and percent of the colored pixels without antrum. Estradiol and leptin increased from day -6 till day 0 but IGF-1 decreased till day -1 but NO achieved a peak on day -3 then decreased till day 0. In conclusion, antrum growth, blood flow and angiogenic hormones play a role in maturation and ovulation of the dominant follicle in mares.Keywords: angiogenic hormones, blood flow, mare, preovulatory follicle
Procedia PDF Downloads 3134426 A 'German Europe' Emerged from the Euro Crisis: A Study through the Portuguese Quality Press
Authors: Ana Luísa Mouro
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When the financial crisis exploded in 2008 in the United States, unleashed by the collapse of Lehman Brothers, and contaminated the economies of the European periphery, Germany appeared as the anchor of the stability of all European institutions and countries in difficulty. The solutions provided by the German government have triggered a deep political debate about the key position Germany has conquered at the heart of Europe - a new “German question” has been created. Some say Germany has achieved by peaceful means what was not able to get through military conquest - the domination of Europe – and many fear Germany’s economic power. This debate about the new role of Germany in Europe has received special attention in the European media and Portugal has not been the exception. The present study has been based on the survey, selection and critical analysis of news reporting, opinion articles, interviews and editorials, published in the weekly Expresso and in the daily Público, between 2008 and 2015 (year of the 25th anniversary of Germany’s unification). The findings of this study will show the paradox of German power and its relevance for Europe’s future.Keywords: Euro crises, German Europe, intercultural hermeneutics, Portuguese quality press
Procedia PDF Downloads 2384425 Creating Database and Building 3D Geological Models: A Case Study on Bac Ai Pumped Storage Hydropower Project
Authors: Nguyen Chi Quang, Nguyen Duong Tri Nguyen
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This article is the first step to research and outline the structure of the geotechnical database in the geological survey of a power project; in the context of this report creating the database that has been carried out for the Bac Ai pumped storage hydropower project. For the purpose of providing a method of organizing and storing geological and topographic survey data and experimental results in a spatial database, the RockWorks software is used to bring optimal efficiency in the process of exploiting, using, and analyzing data in service of the design work in the power engineering consulting. Three-dimensional (3D) geotechnical models are created from the survey data: such as stratigraphy, lithology, porosity, etc. The results of the 3D geotechnical model in the case of Bac Ai pumped storage hydropower project include six closely stacked stratigraphic formations by Horizons method, whereas modeling of engineering geological parameters is performed by geostatistical methods. The accuracy and reliability assessments are tested through error statistics, empirical evaluation, and expert methods. The three-dimensional model analysis allows better visualization of volumetric calculations, excavation and backfilling of the lake area, tunneling of power pipelines, and calculation of on-site construction material reserves. In general, the application of engineering geological modeling makes the design work more intuitive and comprehensive, helping construction designers better identify and offer the most optimal design solutions for the project. The database always ensures the update and synchronization, as well as enables 3D modeling of geological and topographic data to integrate with the designed data according to the building information modeling. This is also the base platform for BIM & GIS integration.Keywords: database, engineering geology, 3D Model, RockWorks, Bac Ai pumped storage hydropower project
Procedia PDF Downloads 1684424 Changing the Biopower Hierarchy between Women’s Bodily Knowledge and the Medical Knowledge about the Body: The Case of Female Ejaculation and #Notpee
Authors: Lior B. Navon
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The objective of this study is to investigate how technology, such as social media, can influence the biopower hierarchy between the medical knowledge about the body and women’s bodily knowledge through the case study of the hashtag 'notpee'. In January 2015, the hashtag #notpee, relating to a feminine physiological phenomenon called female ejaculation (FE) or squirting (SQ) started circulating on twitter. This hashtag, born as a reaction to a medical study claiming that SQ is essentially involuntary emission of urine during sexual activity, sparked an unusual public discourse about FE, a phenomenon that is usually not discussed or referred to in socio-legitimate public spheres. This unusual backlash got the attention of women’s magazines and blogs, as well as more mainstream large and respected outlets such as The Guardian and CNN. Both the tweets on twitter, as well as the media coverage of them, were mainly aimed at rejecting the research’s findings. While not offering an alternative and choosing to define the phenomenon by negation, women argued that the fluid extracted was not pee based on their personal experiences. Based on a critical discourse analysis of 742 tweets with the hashtag 'notpee' between January 2015 and January 2016, and of 15 articles covering the backlash, this study suggests that the #notpee backlash challenged the power balance between the medical knowledge about the feminine body and the feminine bodily knowledge through two different, yet related, forms of resistance to biopower. The first resistance is to the authority over knowledge production — who has the power to produce 'true' statements when it comes to the body? Is it the women who experience the phenomenon, or is it the medical institution? The second resistance to biopower has to do with what we regard as facts or veracity. A critical discourse analysis reveals that while both the scientific field, as well as the women arguing against its findings, use empirical information, they, nevertheless, rely on two dichotomic databases- while the scientific research relies on samples from the 'dead like body', these woman are relying on their lived subjective senses as a source for fact making. Nevertheless, while #notpee is asking to change the power relations between the feminine subjective bodily knowledge and the seemingly objective masculine medical knowledge about the body, it by no means dismisses it. These women are essentially asking the medical institution to take into consideration the subjective body as well as the objective one while acknowledging and accepting the power of the latter over knowledge production.Keywords: biopower, female ejaculation, new media, bodily knowledge
Procedia PDF Downloads 1574423 Investigation of Dynamic Characteristic of Planetary Gear Set Based On Three-Axes Torque Measurement
Authors: Masao Nakagawa, Toshiki Hirogaki, Eiichi Aoyama, Mohamed Ali Ben Abbes
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A planetary gear set is widely used in hybrid vehicles as the power distribution system or in electric vehicles as the high reduction system, but due to its complexity with planet gears, its dynamic characteristic is not fully understood. There are many reports on two-axes driving or displacement of the planet gears under these conditions, but only few reports deal with three-axes driving. A three-axes driving condition is tested using three-axes torque measurement and focuses on the dynamic characteristic around the planet gears in this report. From experimental result, it was confirmed that the transition forces around the planet gears were balanced and the torques were also balanced around the instantaneous rotation center. The meshing frequency under these conditions was revealed to be the harmonics of two meshing frequencies; meshing frequency of the ring gear and that of the planet gears. The input power of the ring gear is distributed to the carrier and the sun gear in the dynamic sequential change of three fixed conditions; planet, star and solar modes.Keywords: dynamic characteristic, gear, planetary gear set, torque measuring
Procedia PDF Downloads 3814422 Energy Consumption Forecast Procedure for an Industrial Facility
Authors: Tatyana Aleksandrovna Barbasova, Lev Sergeevich Kazarinov, Olga Valerevna Kolesnikova, Aleksandra Aleksandrovna Filimonova
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We regard forecasting of energy consumption by private production areas of a large industrial facility as well as by the facility itself. As for production areas the forecast is made based on empirical dependencies of the specific energy consumption and the production output. As for the facility itself implementation of the task to minimize the energy consumption forecasting error is based on adjustment of the facility’s actual energy consumption values evaluated with the metering device and the total design energy consumption of separate production areas of the facility. The suggested procedure of optimal energy consumption was tested based on the actual data of core product output and energy consumption by a group of workshops and power plants of the large iron and steel facility. Test results show that implementation of this procedure gives the mean accuracy of energy consumption forecasting for winter 2014 of 0.11% for the group of workshops and 0.137% for the power plants.Keywords: energy consumption, energy consumption forecasting error, energy efficiency, forecasting accuracy, forecasting
Procedia PDF Downloads 4464421 A Damage Level Assessment Model for Extra High Voltage Transmission Towers
Authors: Huan-Chieh Chiu, Hung-Shuo Wu, Chien-Hao Wang, Yu-Cheng Yang, Ching-Ya Tseng, Joe-Air Jiang
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Power failure resulting from tower collapse due to violent seismic events might bring enormous and inestimable losses. The Chi-Chi earthquake, for example, strongly struck Taiwan and caused huge damage to the power system on September 21, 1999. Nearly 10% of extra high voltage (EHV) transmission towers were damaged in the earthquake. Therefore, seismic hazards of EHV transmission towers should be monitored and evaluated. The ultimate goal of this study is to establish a damage level assessment model for EHV transmission towers. The data of earthquakes provided by Taiwan Central Weather Bureau serve as a reference and then lay the foundation for earthquake simulations and analyses afterward. Some parameters related to the damage level of each point of an EHV tower are simulated and analyzed by the data from monitoring stations once an earthquake occurs. Through the Fourier transform, the seismic wave is then analyzed and transformed into different wave frequencies, and the data would be shown through a response spectrum. With this method, the seismic frequency which damages EHV towers the most is clearly identified. An estimation model is built to determine the damage level caused by a future seismic event. Finally, instead of relying on visual observation done by inspectors, the proposed model can provide a power company with the damage information of a transmission tower. Using the model, manpower required by visual observation can be reduced, and the accuracy of the damage level estimation can be substantially improved. Such a model is greatly useful for health and construction monitoring because of the advantages of long-term evaluation of structural characteristics and long-term damage detection.Keywords: damage level monitoring, drift ratio, fragility curve, smart grid, transmission tower
Procedia PDF Downloads 2994420 FEM Simulations to Study the Effects of Laser Power and Scan Speed on Molten Pool Size in Additive Manufacturing
Authors: Yee-Ting Lee, Jyun-Rong Zhuang, Wen-Hsin Hsieh, An-Shik Yang
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Additive manufacturing (AM) is increasingly crucial in biomedical and aerospace industries. As a recently developed AM technique, selective laser melting (SLM) has become a commercial method for various manufacturing processes. However, the molten pool configuration during SLM of metal powders is a decisive issue for the product quality. It is very important to investigate the heat transfer characteristics during the laser heating process. In this work, the finite element method (FEM) software ANSYS® (work bench module 16.0) was used to predict the unsteady temperature distribution for resolving molten pool dimensions with consideration of temperature-dependent thermal physical properties of TiAl6V4 at different laser powers and scanning speeds. The simulated results of the temperature distributions illustrated that the ratio of laser power to scanning speed can greatly influence the size of molten pool of titanium alloy powder for SLM development.Keywords: additive manufacturing, finite element method, molten pool dimensions, selective laser melting
Procedia PDF Downloads 2864419 The Analysis of Loss-of-Excitation Algorithm for Synchronous Generators
Authors: Pavle Dakić, Dimitrije Kotur, Zoran Stojanović
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This paper presents the results of the study in which the excitation system fault of synchronous generator is simulated. In a case of excitation system fault (loss of field), distance relay is used to prevent further damage. Loss-of-field relay calculates complex impedance using measured voltage and current at the generator terminals. In order to obtain phasors from sampled measured values, discrete Fourier transform is used. All simulations are conducted using Matlab and Simulink software package. The analysis is conducted on the two machine system which supplies equivalent load. While simulating loss of excitation on one generator in different conditions (at idle operation, weakly loaded, and fully loaded), diagrams of active power, reactive power, and measured impedance are analyzed and monitored. Moreover, in the simulations, the effect of generator load on relay tripping time is investigated. In conclusion, the performed tests confirm that the fault in the excitation system can be detected by measuring the impedance.Keywords: loss-of-excitation, synchronous generator, distance protection, Fourier transformation
Procedia PDF Downloads 3314418 Hybrid PWM Techniques for the Reduction of Switching Losses and Voltage Harmonics in Cascaded Multilevel Inverters
Authors: Venkata Reddy Kota
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These days, the industrial trend is moving away from heavy and bulky passive components to power converter systems that use more and more semiconductor elements. Also, it is difficult to connect the traditional converters to the high and medium voltage. For these reasons, a new family of multilevel inverters has appeared as a solution for working with higher voltage levels. Different modulation topologies like Sinusoidal Pulse Width Modulation (SPWM), Selective Harmonic Elimination Pulse Width Modulation (SHE-PWM) are available for multilevel inverters. In this work, different hybrid modulation techniques which are combination of fundamental frequency modulation and multilevel sinusoidal-modulation are compared. The main characteristic of these modulations are reduction of switching losses with good harmonic performance and balanced power loss dissipation among the device. The proposed hybrid modulation schemes are developed and simulated in Matlab/Simulink for cascaded H-bridge inverter. The results validate the applicability of the proposed schemes for cascaded multilevel inverter.Keywords: hybrid PWM techniques, cascaded multilevel inverters, switching loss minimization
Procedia PDF Downloads 6164417 Nigeria Energy Security: The Role of Solar Batteries
Authors: Ihugba Okezie A., Oguzie Emeka E.
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Nigeria's renewable energy market is expanding due to increased environmental awareness, supportive government policies, and the need for energy diversification. This paper examines the role of solar batteries in enhancing Nigeria's energy security. With growing energy demands and frequent power outages, integrating solar batteries presents a viable solution to stabilize the energy supply. The study investigates the current state of solar battery technology in Nigeria, its economic and environmental benefits, and the challenges to implementation. Through a literature review, case studies, and stakeholder interviews, the paper provides a comprehensive analysis of solar batteries' contribution to a resilient energy future. Key players include Engie SA, TotalEnergies SE, Starsight Energy, Enel SpA, and North-South Power Co. Ltd. Challenges include high upfront costs, inadequate policies, weak infrastructure, and security risks. The paper recommends that the government should strengthen policies and incentives to encourage investments through tax breaks, subsidies, and financial incentives.Keywords: renewable energy, solar batteries, energy security, Nigeria’s electricity generation, job creation
Procedia PDF Downloads 404416 Estimation of Solar Radiation Power Using Reference Evaluation of Solar Transmittance, 2 Bands Model: Case Study of Semarang, Central Java, Indonesia
Authors: Benedictus Asriparusa
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Solar radiation is a green renewable energy which has the potential to answer the needs of energy problems on the period. Knowing how to estimate the strength of the solar radiation force may be one solution of sustainable energy development in an integrated manner. Unfortunately, a fairly extensive area of Indonesia is still very low availability of solar radiation data. Therefore, we need a method to estimate the exact strength of solar radiation. In this study, author used a model Reference Evaluation of Solar Transmittance, 2 Bands (REST 2). Validation of REST 2 model has been performed in Spain, India, Colorado, Saudi Arabia, and several other areas. But it is not widely used in Indonesia. Indonesian region study area is represented by the area of Semarang, Central Java. Solar radiation values estimated using REST 2 model was then verified by field data and gives average RMSE value of 6.53%. Based on the value, it can be concluded that the model REST 2 can be used to estimate the value of solar radiation in clear sky conditions in parts of Indonesia.Keywords: estimation, solar radiation power, REST 2, solar transmittance
Procedia PDF Downloads 4274415 Effect of Exercise and Mindfulness on Cognitive and Psycho-Emotional Functioning in Children with ADHD
Authors: Hannah Bigelow, Marcus D. Gottlieb, Michelle Ogrodnik, Jeffrey, D. Graham, Barbara Fenesi
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Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurodevelopmental disorders affecting approximately 6% of children worldwide. ADHD is characterized by a combination of persistent deficits including impaired inhibitory control, working memory and task-switching. Many children with ADHD also have comorbid mental health issues such as anxiety and depression. There are several treatment options to manage ADHD impairments, including drug and behavioural management therapy, but they all have drawbacks, such as worsening mood disturbances or being inaccessible to certain demographics. Both physical exercise and mindfulness meditation serve as alternative options to potentially help mitigate ADHD symptoms. Although there is extensive support for the benefits of long-term physical exercise or mindfulness meditation programs, there is insufficient research investigating how acute bouts (i.e., single, short bouts) can help children with ADHD. Thus, the current study aimed to understand how single, short bouts of exercise and mindfulness meditation impacts executive functioning and psycho-emotional well-being in children with ADHD, as well as to directly compare the efficacy of these two interventions. The study used a a pre- post-test, within-subjects design to assess the effects of a 10-minute bout of moderate intensity exercise versus a 10-minute bout of mindfulness meditation (versus 10 minutes of a reading control) on the executive functioning and psycho-emotional well-being of 16 children and youth with ADHD aged 10-14 (male=11; White=80%). Participants completed all three interventions: 10 minutes of exercise, 10 minutes of mindfulness meditation, and 10 minutes of reading (control). Executive functioning (inhibitory control, working memory, task-switching) and psycho-emotional well-being (mood, self-efficacy) were assessed before and after each intervention. Mindfulness meditation promoted executive functioning, while exercise enhanced positive mood and self-efficacy. Critically, this work demonstrates that a single, short bout of mindfulness meditation session can promote inhibitory control among children with ADHD. This is especially important for children with ADHD as inhibitory control deficits are among the most pervasive challenges that they face. Furthermore, the current study provides preliminary evidence for the benefit of acute exercise for promoting positive mood and general self-efficacy for children and youth with ADHD. These results may increase the accessibility of acute exercise for children with ADHD, providing guardians and teachers a feasible option to incorporate just 10 minutes of exercise to assist children emotionally. In summary, this research supports the use of acute exercise and mindfulness meditation on varying aspects of executive functioning and psycho-emotional well-being in children and youth with ADHD. This work offers important insight into how behavioural interventions could be personalized according to a child’s needs.Keywords: attention-deficit hyperactivity disorder (ADHD), acute exercise, mindfulness meditation, executive functioning, psycho-emotional well-being
Procedia PDF Downloads 1324414 Embracing Complex Femininity: A Comparative Analysis of the Representation of Female Sexuality in John Webster and William Faulkner
Authors: Elisabeth Pedersen
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Representations and interpretations of womanhood and female sexualities bring forth various questions regarding gender norms, and the implications of these norms, which are permeating and repetitive within various societies. Literature is one form of media which provides the space to represent and interpret women, their bodies, and sexualities, and also reveals the power of language as an affective and affected force. As literature allows an opportunity to explore history and the representations of gender, power dynamics, and sexuality through historical contexts, this paper uses engaged theory through a comparative analysis of two work of literature, The Duchess of Malfi by John Wester, and The Sound and the Fury by William Faulkner. These novels span across space and time, which lends to the theory that repetitive tropes of womanhood and female sexuality in literature are influenced by and have an influence on the hegemonic social order throughout history. It analyzes how the representation of the dichotomy of male chivalry and honor, and female purity are disputed and questioned when a woman is portrayed as sexually emancipated, and explores the historical context in which these works were written to examine how socioeconomic events challenged the hegemonic social order. The analysis looks at how stereotypical ideals of womanhood and manhood have damaging implications on women, as the structure of society provides more privilege and power to men than to women, thus creating a double standard for men and women in regards to sexuality, sexual expression, and rights to sexual desire. This comparative analysis reveals how strict gender norms are permeating and have negative consequences. However, re-reading stories through a critical lens can provide an opportunity to challenge the repetitive tropes of female sexuality, and thus lead to the embrace of the complexity of female sexuality and expression.Keywords: femininity, literature, representation, sexuality
Procedia PDF Downloads 3594413 Design, Modification and Structural Analysis of Bicycle Sprocket Using ANSYS
Authors: Roman Kalvin, Saba Arif, Anam Nadeem, Burhan Ali Ghumman, Juntakan Taweekun
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Bicycles are important parts of the transportation industry. In the current world, use of sprocket is very high on bicycles these days. Sprocket and chains are important parts of the transmission of power in the bicycle. However, transmission of power is highly dependent on sprocket design. In conventional bicycles, sprockets are made up of mild steel which undergoes wear and tears with the passage of time due to high pressures applied on it. In the current research, a new sprocket is designed by changing its structure and material to carbon fiber from mild steel. The existing sprocket of a bicycle is compared with the new and modified sprocket design. However, new design has structural and material changes as well. According to the results, in carbon fiber, sprocket deformation is 0.091 mm while sprocket stress value is 371.13N/mm². Also, comparison based analysis is done by physical testing and software analysis. There is 8.1% variation in software and experimental results of steel. Additionally, the difference between both methods comes 8 to 9%. This improved design can be used in future for more durability and long run timings for bicycles.Keywords: sprocket, mild steel, drafting, stress, deformation
Procedia PDF Downloads 2544412 Impact of Foreign Direct Investment on Woman's Lifestyle: A Female Banking Professionals Case Study
Authors: Ruqiya Anwar
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The present study is aimed to find out the Impact of Foreign direct Investment on lifestyle of working women in Rawalpindi and Islamabad (Pakistan). It was hypothesized that easy access to consumer loans uplifts the lifestyle of women. First part of the research study was aimed at developing a tool to measure the Impact of FDI on living pattern of women in Rawalpindi and Islamabad. Purposive sampling technique was used to collect the more reliable and valid data.81 females working in different banks of Rawalpindi and Islamabad (Pakistan) were included in the sample. The value of Alpha Reliability coefficient is .774 for the tool of study. Which was found satisfactory and indicated that tool is reliable to measure the study objectives. Finding of the study showed that foreign direct investment has significant and positive impact on lifestyle of women in Rawalpindi and Islamabad (Pakistan). Study also revealed that there is moderate and high level of consumption power women have through foreign direct investment, which supports the hypothesis.Keywords: foreign direct investment, lifestyle of women, consumption power, consumer loans
Procedia PDF Downloads 3504411 Reduction of Energy Consumption Using Smart Home Techniques in the Household Sector
Authors: Ahmed Al-Adaileh, Souheil Khaddaj
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Outcomes of exhaustion of natural resources started influencing each spirit on this planet. Energy is an essential factor in this aspect. To restore the circumstance to the appropriate track, all attempts must focus on two fundamental branches: producing electricity from clean and renewable reserves and decreasing the overall unnecessary consumption of energy. The focal point of this paper will be on lessening the power consumption in the household's segment. This paper is an attempt to give a clear understanding of a framework called Reduction of Energy Consumption in Household Sector (RECHS) and how it should help householders to reduce their power consumption by substituting their household appliances, turning-off the appliances when stand-by modus is detected, and scheduling their appliances operation periods. Technically, the framework depends on utilizing Z-Wave compatible plug-ins which will be connected to the usual house devices to gauge and control them remotely and semi-automatically. The suggested framework underpins numerous quality characteristics, for example, integrability, scalability, security and adaptability.Keywords: smart energy management systems, internet of things, wireless mesh networks, microservices, cloud computing, big data
Procedia PDF Downloads 1964410 The Incesant Subversion of Judiciary by African Political Leaders
Authors: Joy Olayemi Gbala, Fatai Olatokunbo, Philip Cloud
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Catastrophic dictatorship has been discovered to be the major leadership challenge that orchestrates stagnated and contrasted economy with dysfunctional democracy in Africa through willful misappropriation of resources and egregious subversion of the rule of law. Almost invariably, most African leaders inexplicably often become power drunk and addicted which usually leads to abuse of state power, abdication of constitutional duties, unjustly withdrawal of business license of operation, human right violation, election malpractices, financial corruption, disruptions of policies of democratic government transition, annulment of free and fair election, and disruptions of legal electoral procedures and unachievable dividends of democracy and many more. Owing to this, most African nations have gone and still go through political unrest and insurgencies leading to loss of lives and property, violent protests, detention of detractors and political activists and massive human displacement. This research work is concerned with, and investigates the causes, menace, consequences and impacts of subverting the rule of law in Africa on the economy and the development of the continent with a suggested practical solution to the plights.Keywords: corruption, law, leadership, violation
Procedia PDF Downloads 1554409 Performance Analysis of Bluetooth Low Energy Mesh Routing Algorithm in Case of Disaster Prediction
Authors: Asmir Gogic, Aljo Mujcic, Sandra Ibric, Nermin Suljanovic
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Ubiquity of natural disasters during last few decades have risen serious questions towards the prediction of such events and human safety. Every disaster regardless its proportion has a precursor which is manifested as a disruption of some environmental parameter such as temperature, humidity, pressure, vibrations and etc. In order to anticipate and monitor those changes, in this paper we propose an overall system for disaster prediction and monitoring, based on wireless sensor network (WSN). Furthermore, we introduce a modified and simplified WSN routing protocol built on the top of the trickle routing algorithm. Routing algorithm was deployed using the bluetooth low energy protocol in order to achieve low power consumption. Performance of the WSN network was analyzed using a real life system implementation. Estimates of the WSN parameters such as battery life time, network size and packet delay are determined. Based on the performance of the WSN network, proposed system can be utilized for disaster monitoring and prediction due to its low power profile and mesh routing feature.Keywords: bluetooth low energy, disaster prediction, mesh routing protocols, wireless sensor networks
Procedia PDF Downloads 3854408 Computational Fluid Dynamics Simulation of a Boiler Outlet Header Constructed of Inconel Alloy 740H
Authors: Sherman Ho, Ahmed Cherif Megri
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Headers play a critical role in conveying steam to regulate heating system temperatures. While various materials like steel grades 91 and 92 have been traditionally used for pipes, this research proposes the use of a robust and innovative material, INCONEL Alloy 740H. Boilers in power plant configurations are exposed to cycling conditions due to factors such as daily, seasonal, and yearly variations in weather. These cycling conditions can lead to the deterioration of headers, which are vital components with intricate geometries. Header failures result in substantial financial losses from repair costs and power plant shutdowns, along with significant public inconveniences such as the loss of heating and hot water. To address this issue and seek solutions, a mechanical analysis, as well as a structural analysis, are recommended. Transient analysis to predict heat transfer conditions is of paramount importance, as the direction of heat transfer within the header walls and the passing steam can vary based on the location of interest, load, and operating conditions. The geometry and material of the header are also crucial design factors, and the choice of pipe material depends on its usage. In this context, the heat transfer coefficient plays a vital role in header design and analysis. This research employs ANSYS Fluent, a numerical simulation program, to understand header behavior, predict heat transfer, and analyze mechanical phenomena within the header. Transient simulations are conducted to investigate parameters like heat transfer coefficient, pressure loss coefficients, and heat flux, with the results used to optimize header design.Keywords: CFD, header, power plant, heat transfer coefficient, simulation using experimental data
Procedia PDF Downloads 664407 Design and Development of Real-Time Optimal Energy Management System for Hybrid Electric Vehicles
Authors: Masood Roohi, Amir Taghavipour
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This paper describes a strategy to develop an energy management system (EMS) for a charge-sustaining power-split hybrid electric vehicle. This kind of hybrid electric vehicles (HEVs) benefit from the advantages of both parallel and series architecture. However, it gets relatively more complicated to manage power flow between the battery and the engine optimally. The applied strategy in this paper is based on nonlinear model predictive control approach. First of all, an appropriate control-oriented model which was accurate enough and simple was derived. Towards utilization of this controller in real-time, the problem was solved off-line for a vast area of reference signals and initial conditions and stored the computed manipulated variables inside look-up tables. Look-up tables take a little amount of memory. Also, the computational load dramatically decreased, because to find required manipulated variables the controller just needed a simple interpolation between tables.Keywords: hybrid electric vehicles, energy management system, nonlinear model predictive control, real-time
Procedia PDF Downloads 3524406 Transformational Leadership and Its Effect on Teacher Job Satisfaction
Authors: Shujie Liu
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This study aimed to investigate the relationship between teachers’ perceived transformational leadership behaviors and their job satisfaction in China after controlling for teacher self-efficacy. Hierarchical regression analysis (HRA) technique was employed to examine factors’ contributions to teacher job satisfaction with a sample of Chinese high school teachers. The finding of this study provided evidence that teachers’ perceived transformational leadership behaviors accounted for a large percentage (44.9%) of the variance in Chinese teachers’ job satisfaction. Uniquely, school principals’ sense of power was a negative significant predictor of teacher job satisfaction, meaning that the more teachers perceived their principals’ sense of power, the lower of their job satisfaction. Furthermore, this study provided evidence that teacher self-efficacy significantly contributes to teacher job satisfaction. Specifically, teachers’ self-efficacy on student engagement was found to be a significant predictor of teacher job satisfaction. The conclusions were discussed in terms of Chinese cultures. The authors pointed out that how to make teachers involved in school policy making is a challenge for China and that more shared leadership is needed in Chinese schools.Keywords: Chinese teachers, teacher job satisfaction, teacher self-efficacy, transformational leadership
Procedia PDF Downloads 496