Search results for: power intensity levels colors
13688 Influence of Laser Excitation on SERS of Silicon Nanocrystals
Authors: Khamael M. Abualnaja, Lidija Šiller, Ben R. Horrocks
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Surface enhanced Raman spectroscopy (SERS) of Silicon nano crystals (SiNCs) were obtained using two different laser excitations: 488 nm and 514.5 nm. Silver nano particles were used as plasmonics metal nano particles due to a robust SERS effect that observed when they mixed with SiNCs. SiNCs have been characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the SiNCs are crystalline with an average diameter of 65 nm and FCC lattice. Silver nano particles (AgNPs) of two different sizes were synthesized using photo chemical reduction of AgNO3 with sodium dodecyl sulfate (SDS). The synthesized AgNPs have a polycrystalline structure with an average particle diameter of 100 nm and 30 nm, respectively. A significant enhancement in the SERS intensity was observed for AgNPs100/SiNCs and AgNPs30/SiNCs mixtures increasing up to 9 and 3 times respectively using 488 nm intensity; whereas the intensity of the SERS signal increased up to 7 and 2 times respectively, using 514.5 nm excitation source. The enhancement in SERS intensities occurs as a result of the coupling between the excitation laser light and the plasmon bands of AgNPs; thus this intense field at AgNPs surface couples strongly to SiNCs. The results provide good consensus between the wavelength of the laser excitation source and surface plasmon resonance absorption band of silver nano particles consider to be an important requirement in SERS experiments.Keywords: silicon nanocrystals (SiNCs), silver nanoparticles (AgNPs), surface enhanced raman spectroscopy (SERS)
Procedia PDF Downloads 32513687 Evaluating and Examining Pictures of Children of Five Years Old
Authors: Emine Yılmaz Bolat
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Early childhood is a very important period in terms of identifying and developing early skills and abilities. It is likely that the child's development will be in the same direction in the future. This study was conducted with 26 children for the purpose of examining pictures of children of five years old. In the survey, children were asked to draw a picture with pastel dyes. The drawings were collected and evaluated by the researcher. At the end of the research, it was found that the children used the yellow color (N = 17, 16,34%) and the least gray color (N = 1, 0,96%). When the features of children's pictures are examined, the children's paintings have been found to have hierarchy, transparency, completion, the use of vivid colors, and the presence of vertical and horizontal painting lines.Keywords: early childhood, kindergarten, pictures of children, features of pictures
Procedia PDF Downloads 29713686 Active Power Control of PEM Fuel Cell System Power Generation Using Adaptive Neuro-Fuzzy Controller
Authors: Khaled Mammar
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This paper presents an application of adaptive neuro-fuzzy controller for PEM fuel cell system. The model proposed for control include a fuel cell stack model, reformer model and DC/AC inverter model. Furthermore, a Fuzzy Logic (FLC) and adaptive neuro-fuzzy controllers are used to control the active power of PEM fuel cell system. The controllers modify the hydrogen flow feedback from the terminal load. The validity of the controller is verified when the fuel cell system model is used in conjunction with the ANFIS controller to predict the response of the active power. Simulation results confirmed the high-performance capability of the neuo-fuzzy to control power generation.Keywords: fuel cell, PEMFC, modeling, simulation, Fuzzy Logic Controller, FLC, adaptive neuro-fuzzy controller, ANFIS
Procedia PDF Downloads 45013685 Effect of High Intensity Interval Training and Moderate Interval Continuous Training on Cardiovascular Endurance In young Healthy Female
Authors: Sidra Majeed, Irum Ali, Aroosa Ishfaq, Munazzah Parveen
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Objectives: The objective is to compare the effects of high-intensity interval training VS moderate moderate-intensity continuous training on cardiovascular endurance in young healthy females. Method: 30 young, healthy females were collected and randomly assigned into two training groups, HIIT and MICT, each group having a sample size of (n=15). There will be three parameters to be tested, including (VO2max, Resting heart rate, and Rate perceived exertion). Each group will be tested at three different times, e.g. (at Baseline measurement, after two weeks and after four weeks). For the first two weeks, the HIIT group has to perform at 70%HRR and for the third and fourth weeks, at 75%HRR for two minutes, followed by an active resting interval at 30%HRR for two minutes (1:1) with warm-up and cool-down period (2 minutes each period ) on the treadmill. For the first two weeks, the MICT group has to perform at 40%HRR and for the third and fourth weeks at 50% HRR for fifteen minutes continuously on the treadmill, including warm up and cool down period (2 minutes each period). Result: The final assessment of HIIT and MICT groups had shown p values for VO2max (p=.000), RHR (p=.323) and for RPE (p=.085). These values indicating significant improvement in these three parameters in both groups. Conclusion: This study showed that there were significant improvements in both groups but there were more improvements in VO2max in HIIT group so, it is proved that HIIT is more beneficial than MICT in improving cardiovascular endurance.Keywords: HIIT, MICT, RPE, RHR
Procedia PDF Downloads 3613684 Transmit Power Optimization for Cooperative Beamforming in Reverse-Link MIMO Ad-Hoc Networks
Authors: Younghyun Jeon, Seungjoo Maeng
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In the Ad-hoc network, the great interests regarding MIMO scheme leads to their combination, which is also utilized into its applicable network. We manage the field of the problem into Reverse-link MIMO Ad-hoc Network (RMAN) and propose the methodology to maximize the data rate with its power consumption using Node-Cooperative beamforming technique. Based on the result of mathematical optimization formulation, we design the algorithm to construct optimal orthogonal weight vector according to channel feedback and control its transmission power according to QoS-pricing value level. In simulation results, we show the validity of the proposed mathematical optimization result and algorithm which mean that the sum-rate of each link is converged into some point.Keywords: ad-hoc network, MIMO, cooperative beamforming, transmit power
Procedia PDF Downloads 38913683 Health Assessment of Power Transformer Using Fuzzy Logic
Authors: Yog Raj Sood, Rajnish Shrivastava, Anchal Wadhwa
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Power transformer is one of the electrical equipment that has a central and critical role in the power system. In order to avoid power transformer failure, information system that provides the transformer condition is needed. This paper presents an information system to know the exact situations prevailing within the transformer by declaring its health index. Health index of a transformer is decided by considering several diagnostic tools. The current work deals with UV-Vis, IFT, FP, BDV and Water Content. UV/VIS results have been pre-accessed using separate FL controller for concluding with the Furan contents. It is broadly accepted that the life of a power transformer is the life of the oil/ paper insulating system. The method relies on the use of furan analysis (insulation paper), and other oil analysis results as a means to declare health index. Fuzzy logic system is used to develop the information system. The testing is done on 5 samples of oil of transformers of rating 132/66 KV to obtain the results and results are analyzed using fuzzy logic model.Keywords: interfacial tension analyzer (ift), flash point (fp), furfuraldehyde (fal), health index
Procedia PDF Downloads 62213682 Application of Data Driven Based Models as Early Warning Tools of High Stream Flow Events and Floods
Authors: Mohammed Seyam, Faridah Othman, Ahmed El-Shafie
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The early warning of high stream flow events (HSF) and floods is an important aspect in the management of surface water and rivers systems. This process can be performed using either process-based models or data driven-based models such as artificial intelligence (AI) techniques. The main goal of this study is to develop efficient AI-based model for predicting the real-time hourly stream flow (Q) and apply it as early warning tool of HSF and floods in the downstream area of the Selangor River basin, taken here as a paradigm of humid tropical rivers in Southeast Asia. The performance of AI-based models has been improved through the integration of the lag time (Lt) estimation in the modelling process. A total of 8753 patterns of Q, water level, and rainfall hourly records representing one-year period (2011) were utilized in the modelling process. Six hydrological scenarios have been arranged through hypothetical cases of input variables to investigate how the changes in RF intensity in upstream stations can lead formation of floods. The initial SF was changed for each scenario in order to include wide range of hydrological situations in this study. The performance evaluation of the developed AI-based model shows that high correlation coefficient (R) between the observed and predicted Q is achieved. The AI-based model has been successfully employed in early warning throughout the advance detection of the hydrological conditions that could lead to formations of floods and HSF, where represented by three levels of severity (i.e., alert, warning, and danger). Based on the results of the scenarios, reaching the danger level in the downstream area required high RF intensity in at least two upstream areas. According to results of applications, it can be concluded that AI-based models are beneficial tools to the local authorities for flood control and awareness.Keywords: floods, stream flow, hydrological modelling, hydrology, artificial intelligence
Procedia PDF Downloads 24013681 Investigating the Performance of Power Industry in a Developing Nation for Industrialization and Environmental Security
Authors: Abel Edeowede Abhulimen
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Due to supply irregularity and frequent outages, the need for reliability in power supply has grown unsatisfactorily over time in developing nations, impeding industrialization and fueling insecurity. This article attempts to break down the Nigerian power issue into its numerous sub-sectors in order to pinpoint the industry's ailment and suggest a viable fix. Monthly average performance data were obtained for the various sub-sectors across the industry for eight consecutive quarters. Whereas the amount of energy generated was found to be insufficient to engender industrialization in a nation like Nigeria, the transmission infrastructure was inadequate for the amount of power needed to be wheeled. Additionally, the distribution sub-sector was plagued with problems such as revenue collection inefficiency, severe enough to impede the growth of the entire industry. The country's goal of attaining energy sufficiency and industrialization would significantly be closer to reality with a conscious effort to increase the base of power generation through aggressive investment in Combined Cycle Gas Turbines (CCGT), decentralization of the transmission infrastructure, and strict monitoring of the distribution sub-sector for improved accountability and system reliability.Keywords: performance, power industry, industrialization, security, energy
Procedia PDF Downloads 5713680 Effect of Gamma Irradiation on Structural and Optical Properties of ZnO/Mesoporous Silica Nanocomposite
Authors: K. Sowri Babu, P. Srinath, N. Rajeswara Rao, K. Venugopal Reddy
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The effect of gamma ray irradiation on morphology and optical properties of ZnO/Mesoporous silica (MPS) nanocomposite was studied. The ZnO/MPS nanocomposite was irradiated with gamma rays of doses 30, 60, and 90 kGy and dose-rate of irradiation was 0.15 kGy/hour. Irradiated samples are characterized with FE-SEM, FT-IR, UV-vis, and Photoluminescence (PL) spectrometers. SEM pictures showed that morphology changed from spherical to flake like morphology. UV-vis analysis showed that the band gap increased with increase of gamma ray irradiation dose. This enhancement of the band gap is assigned to the depletion of oxygen vacancies with irradiation. The intensity of PL peak decreased gradually with increase of gamma ray irradiation dose. The decrease in PL intensity is attributed to the decrease of oxygen vacancies at the interface due to poor interface and improper passivation between ZnO/MPS.Keywords: ZnO nanoparticles, nanocomposites, mesoporous silica, photoluminescence
Procedia PDF Downloads 22513679 Coils and Antennas Fabricated with Sewing Litz Wire for Wireless Power Transfer
Authors: Hikari Ryu, Yuki Fukuda, Kento Oishi, Chiharu Igarashi, Shogo Kiryu
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Recently, wireless power transfer has been developed in various fields. Magnetic coupling is popular for feeding power at a relatively short distance and at a lower frequency. Electro-magnetic wave coupling at a high frequency is used for long-distance power transfer. The wireless power transfer has attracted attention in e-textile fields. Rigid batteries are required for many body-worn electric systems at the present time. The technology enables such batteries to be removed from the systems. Flexible coils have been studied for such applications. Coils with a high Q factor are required in the magnetic-coupling power transfer. Antennas with low return loss are needed for the electro-magnetic coupling. Litz wire is so flexible to fabricate coils and antennas sewn on fabric and has low resistivity. In this study, the electric characteristics of some coils and antennas fabricated with the Litz wire by using two sewing techniques are investigated. As examples, a coil and an antenna are described. Both were fabricated with 330/0.04 mm Litz wire. The coil was a planar coil with a square shape. The outer side was 150 mm, the number of turns was 15, and the pitch interval between each turn was 5 mm. The Litz wire of the coil was overstitched with a sewing machine. The coil was fabricated as a receiver coil for a magnetic coupled wireless power transfer. The Q factor was 200 at a frequency of 800 kHz. A wireless power system was constructed by using the coil. A power oscillator was used in the system. The resonant frequency of the circuit was set to 123 kHz, where the switching loss of power FETs was small. The power efficiencies were 0.44 – 0.99, depending on the distance between the transmitter and receiver coils. As an example of an antenna with a sewing technique, a fractal pattern antenna was stitched on a 500 mm x 500 mm fabric by using a needle punch method. The pattern was the 2nd-oder Vicsec fractal. The return loss of the antenna was -28 dB at a frequency of 144 MHz.Keywords: e-textile, flexible coils and antennas, Litz wire, wireless power transfer
Procedia PDF Downloads 12213678 Parallel Version of Reinhard’s Color Transfer Algorithm
Authors: Abhishek Bhardwaj, Manish Kumar Bajpai
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An image with its content and schema of colors presents an effective mode of information sharing and processing. By changing its color schema different visions and prospect are discovered by the users. This phenomenon of color transfer is being used by Social media and other channel of entertainment. Reinhard et al’s algorithm was the first one to solve this problem of color transfer. In this paper, we make this algorithm efficient by introducing domain parallelism among different processors. We also comment on the factors that affect the speedup of this problem. In the end by analyzing the experimental data we claim to propose a novel and efficient parallel Reinhard’s algorithm.Keywords: Reinhard et al’s algorithm, color transferring, parallelism, speedup
Procedia PDF Downloads 60313677 Maximum Power Point Tracking Using FLC Tuned with GA
Authors: Mohamed Amine Haraoubia, Abdelaziz Hamzaoui, Najib Essounbouli
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The pursuit of the MPPT has led to the development of many kinds of controllers, one of which is the Fuzzy Logic Controller, which has proven its worth. To further tune this controller this paper will discuss and analyze the use of Genetic Algorithms to tune the Fuzzy Logic Controller. It will provide an introduction to both systems, and test their compatibility and performance.Keywords: fuzzy logic controller, fuzzy logic, genetic algorithm, maximum power point, maximum power point tracking
Procedia PDF Downloads 36513676 The Chromatic Identity of the Ancestral Architecture of the Ksour of Bechar, Algeria
Authors: Racha Ghariri, Khaldia Belkheir, Assil Ghariri
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In this paper, the researchers present a part of their research on the colors of the city of Bechar (Algeria). It is about a chromatic study of the ancient architecture of the Ksour. Being a subject of intervention, regarding their degradable state, the Ksour are the case of their study, especially that the subject of color does not occupy, virtually, the involved on these heritage sites. This research aims to put the basics for methods which allow to know what to preserve as a color and how to do so, especially during a restoration, and to understand the evolution of the chromatic state of the city.Keywords: architecture/colours, chromatic identity, geography of colour, regional palette, chromatic architectural analysis
Procedia PDF Downloads 29613675 Generation of Photo-Mosaic Images through Block Matching and Color Adjustment
Authors: Hae-Yeoun Lee
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Mosaic refers to a technique that makes image by gathering lots of small materials in various colours. This paper presents an automatic algorithm that makes the photomosaic image using photos. The algorithm is composed of four steps: Partition and feature extraction, block matching, redundancy removal and colour adjustment. The input image is partitioned in the small block to extract feature. Each block is matched to find similar photo in database by comparing similarity with Euclidean difference between blocks. The intensity of the block is adjusted to enhance the similarity of image by replacing the value of light and darkness with that of relevant block. Further, the quality of image is improved by minimizing the redundancy of tiles in the adjacent blocks. Experimental results support that the proposed algorithm is excellent in quantitative analysis and qualitative analysis.Keywords: photomosaic, Euclidean distance, block matching, intensity adjustment
Procedia PDF Downloads 27313674 Numerical Simulation of Multiple Arrays Arrangement of Micro Hydro Power Turbines
Authors: M. A. At-Tasneem, N. T. Rao, T. M. Y. S. Tuan Ya, M. S. Idris, M. Ammar
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River flow over micro hydro power (MHP) turbines of multiple arrays arrangement is simulated with computational fluid dynamics (CFD) software to obtain the flow characteristics. In this paper, CFD software is used to simulate the water flow over MHP turbines as they are placed in a river. Multiple arrays arrangement of MHP turbines lead to generate large amount of power. In this study, a river model is created and simulated in CFD software to obtain the water flow characteristic. The process then continued by simulating different types of arrays arrangement in the river model. A MHP turbine model consists of a turbine outer body and static propeller blade in it. Five types of arrangements are used which are parallel, series, triangular, square and rhombus with different spacing sizes. The velocity profiles on each MHP turbines are identified at the mouth of each turbine bodies. This study is required to obtain the arrangement with increasing spacing sizes that can produce highest power density through the water flow variation.Keywords: micro hydro power, CFD, arrays arrangement, spacing sizes, velocity profile, power
Procedia PDF Downloads 35313673 Dy³+/Eu³+ Co-Activated Gadolinium Aluminate Borate Phosphor: Enhanced Luminescence and Color Output Tuning
Authors: Osama Madkhali
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GdAl₃(BO₃)₄ phosphors, incorporating Dy³+ and Dy³+/Eu³+ activators, were successfully synthesized via the gel combustion method. Powder X-ray diffraction (XRD) was utilized to ascertain phase purity and assess the impact of dopant concentration on the crystallographic structure. Photoluminescence (PL) measurements revealed that luminescence properties' intensity and lifetime varied with Dy³+ and Eu³+ ion concentrations. The relationship between luminescence intensity and doping concentration was explored in the context of the energy transfer process between Eu³+ and Dy³+ ions. An increase in Eu³+ co-doping concentrations resulted in a decrease in luminescence lifetime. Energy transfer efficiency was significantly enhanced from 26% to 84% with Eu³+ co-doping, as evidenced by decay curve analysis. These findings position GdAl₃(BO₃)4: Dy³+, Eu³+ phosphors as promising candidates for LED applications in solid-state lighting and displays.Keywords: GdAl₃(BO₃)₄ phosphors, Dy³+/Eu³+ co-doping, photoluminescence (PL) measurements, luminescence properties, LED applications, solid-state lighting
Procedia PDF Downloads 4813672 High-Tech Based Simulation and Analysis of Maximum Power Point in Energy System: A Case Study Using IT Based Software Involving Regression Analysis
Authors: Enemeri George Uweiyohowo
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Improved achievement with respect to output control of photovoltaic (PV) systems is one of the major focus of PV in recent times. This is evident to its low carbon emission and efficiency. Power failure or outage from commercial providers, in general, does not promote development to public and private sector, these basically limit the development of industries. The need for a well-structured PV system is of importance for an efficient and cost-effective monitoring system. The purpose of this paper is to validate the maximum power point of an off-grid PV system taking into consideration the most effective tilt and orientation angles for PV's in the southern hemisphere. This paper is based on analyzing the system using a solar charger with MPPT from a pulse width modulation (PWM) perspective. The power conditioning device chosen is a solar charger with MPPT. The practical setup consists of a PV panel that is set to an orientation angle of 0∘N, with a corresponding tilt angle of 36∘, 26∘ and 16∘. Preliminary results include regression analysis (normal probability plot) showing the maximum power point in the system as well the best tilt angle for maximum power point tracking.Keywords: poly-crystalline PV panels, information technology (IT), maximum power point tracking (MPPT), pulse width modulation (PWM)
Procedia PDF Downloads 20413671 The Foucaultian Relationship between Power and Knowledge: Genealogy as a Method for Epistemic Resistance
Authors: Jana Soler Libran
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The primary aim of this paper is to analyze the relationship between power and knowledge suggested in Michel Foucault's theory. Taking into consideration the role of power in knowledge production, the goal is to evaluate to what extent genealogy can be presented as a practical method for epistemic resistance. To do so, the methodology used consists of a revision of Foucault’s literature concerning the topic discussed. In this sense, conceptual analysis is applied in order to understand the effect of the double dimension of power on knowledge production. In its negative dimension, power is conceived as an organ of repression, vetoing certain instances of knowledge considered deceitful. In opposition, in its positive dimension, power works as an organ of the production of truth by means of institutionalized discourses. This double declination of power leads to the first main findings of the present analysis: no truth or knowledge can lie outside power’s action, and power is constituted through accepted forms of knowledge. To second these statements, Foucaultian discourse formations are evaluated, presenting external exclusion procedures as paradigmatic practices to demonstrate how power creates and shapes the validity of certain epistemes. Thus, taking into consideration power’s mechanisms to produce and reproduce institutionalized truths, this paper accounts for the Foucaultian praxis of genealogy as a method to reveal power’s intention, instruments, and effects in the production of knowledge. In this sense, it is suggested to consider genealogy as a practice which, firstly, reveals what instances of knowledge are subjugated to power and, secondly, promotes aforementioned peripherical discourses as a form of epistemic resistance. In order to counterbalance these main theses, objections to Foucault’s work from Nancy Fraser, Linda Nicholson, Charles Taylor, Richard Rorty, Alvin Goldman, or Karen Barad are discussed. In essence, the understanding of the Foucaultian relationship between power and knowledge is essential to analyze how contemporary discourses are produced by both traditional institutions and new forms of institutionalized power, such as mass media or social networks. Therefore, Michel Foucault's practice of genealogy is relevant, not only for its philosophical contribution as a method to uncover the effects of power in knowledge production but also because it constitutes a valuable theoretical framework for political theory and sociological studies concerning the formation of societies and individuals in the contemporary world.Keywords: epistemic resistance, Foucault’s genealogy, knowledge, power, truth
Procedia PDF Downloads 11213670 A SiGe Low Power RF Front-End Receiver for 5.8GHz Wireless Biomedical Application
Authors: Hyunwon Moon
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It is necessary to realize new biomedical wireless communication systems which send the signals collected from various bio sensors located at human body in order to monitor our health. Also, it should seamlessly connect to the existing wireless communication systems. A 5.8 GHz ISM band low power RF front-end receiver for a biomedical wireless communication system is implemented using a 0.5 µm SiGe BiCMOS process. To achieve low power RF front-end, the current optimization technique for selecting device size is utilized. The implemented low noise amplifier (LNA) shows a power gain of 9.8 dB, a noise figure (NF) of below 1.75 dB, and an IIP3 of higher than 7.5 dBm while current consumption is only 6 mA at supply voltage of 2.5 V. Also, the performance of a down-conversion mixer is measured as a conversion gain of 11 dB and SSB NF of 10 dB.Keywords: biomedical, LNA, mixer, receiver, RF front-end, SiGe
Procedia PDF Downloads 31013669 Optimal Planning of Dispatchable Distributed Generators for Power Loss Reduction in Unbalanced Distribution Networks
Authors: Mahmoud M. Othman, Y. G. Hegazy, A. Y. Abdelaziz
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This paper proposes a novel heuristic algorithm that aims to determine the best size and location of distributed generators in unbalanced distribution networks. The proposed heuristic algorithm can deal with the planning cases where power loss is to be optimized without violating the system practical constraints. The distributed generation units in the proposed algorithm is modeled as voltage controlled node with the flexibility to be converted to constant power factor node in case of reactive power limit violation. The proposed algorithm is implemented in MATLAB and tested on the IEEE 37 -node feeder. The results obtained show the effectiveness of the proposed algorithm.Keywords: distributed generation, heuristic approach, optimization, planning
Procedia PDF Downloads 50913668 Media, Politics and Power in the Representation of the Refugee and Migration Crisis in Europe
Authors: Evangelia-Matroni Tomara
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This thesis answers the question whether the media representations and reporting in 2015-2016 - especially, after the image of the drowned three-year-old Syrian boy in the Mediterranean Sea which made global headlines in the beginning of September 2015 -, the European Commission regulatory sources material and related reporting, have the power to challenge the conceptualization of humanitarianism or even redefine it. The theoretical foundations of the thesis are based on humanitarianism and its core definitions, the power of media representations and the relative portrayal of migrants, refugees and/or asylum seekers, as well as the dominant migration discourse and EU migration governance. Using content analysis for the media portrayal of migrants (436 newspaper articles) and qualitative content analysis for the European Commission Communication documents from May 2015 until June 2016 that required various depths of interpretation, this thesis allowed us to revise the concept of humanitarianism, realizing that the current crisis may seem to be a turning point for Europe but is not enough to overcome the past hostile media discourses and suppress the historical perspective of security and control-oriented EU migration policies. In particular, the crisis helped to shift the intensity of hostility and the persistence in the state-centric, border-oriented securitization in Europe into a narration of victimization rather than threat where mercy and charity dynamics are dominated and into operational mechanisms, noting the emergency of immediate management of the massive migrations flows, respectively. Although, the understanding of a rights-based response to the ongoing migration crisis, is being followed discursively in both political and media stage, the nexus described, points out that the binary between ‘us’ and ‘them’ still exists, with only difference that the ‘invaders’ are now ‘pathetic’ but still ‘invaders’. In this context, the migration crisis challenges the concept of humanitarianism because rights dignify migrants as individuals only in a discursive or secondary level while the humanitarian work is mostly related with the geopolitical and economic interests of the ‘savior’ states.Keywords: European Union politics, humanitarianism, immigration, media representation, policy-making, refugees, security studies
Procedia PDF Downloads 28713667 Worst-Case Load Shedding in Electric Power Networks
Authors: Fu Lin
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We consider the worst-case load-shedding problem in electric power networks where a number of transmission lines are to be taken out of service. The objective is to identify a prespecified number of line outages that lead to the maximum interruption of power generation and load at the transmission level, subject to the active power-flow model, the load and generation capacity of the buses, and the phase-angle limit across the transmission lines. For this nonlinear model with binary constraints, we show that all decision variables are separable except for the nonlinear power-flow equations. We develop an iterative decomposition algorithm, which converts the worst-case load shedding problem into a sequence of small subproblems. We show that the subproblems are either convex problems that can be solved efficiently or nonconvex problems that have closed-form solutions. Consequently, our approach is scalable for large networks. Furthermore, we prove the convergence of our algorithm to a critical point, and the objective value is guaranteed to decrease throughout the iterations. Numerical experiments with IEEE test cases demonstrate the effectiveness of the developed approach.Keywords: load shedding, power system, proximal alternating linearization method, vulnerability analysis
Procedia PDF Downloads 13413666 Determination of Organizational Cynicism Levels of Health Care Workers
Authors: Murat İskender Aktaş, Selma Söyük
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The aim of this work is to specify the levels of organizational cynicism health workers. Organizational cynicism concept is evaluated in three sub-branches and these are cognitive, affective, and behavioral. The main objective of the work is to answer the questions about the relationship of demographic characteristics like sub-branches of cynicism and age, marital status, education level, total working hours, occupational groups and income levels. As works in our country are analyzed, there have been studies about cynicism in health and other sectors. However, there were no master’s thesis or organizational cynicism research found about the public health professionals. This is why the aim was chosen as to specify the levels of organizational cynicism of public health professionals. The average of the answers of the health workers to the questions about cynicism levels are 2.86. As organizational cynicism is evaluated according to the sub-branches, cognitive subscale average score is 3.21 affective subscale average score is 2.68 and behavioral subscale average score is counted as 2.67. As the results are analyzed, it is seen that the behavioral subscale has the highest average. This shows that the workers are often criticizing the internal complaints and organizational information with their friends out of the organization.Keywords: cynicism, organizational cynicism, health care workers
Procedia PDF Downloads 32613665 Transfer Function Model-Based Predictive Control for Nuclear Core Power Control in PUSPATI TRIGA Reactor
Authors: Mohd Sabri Minhat, Nurul Adilla Mohd Subha
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The 1MWth PUSPATI TRIGA Reactor (RTP) in Malaysia Nuclear Agency has been operating more than 35 years. The existing core power control is using conventional controller known as Feedback Control Algorithm (FCA). It is technically challenging to keep the core power output always stable and operating within acceptable error bands for the safety demand of the RTP. Currently, the system could be considered unsatisfactory with power tracking performance, yet there is still significant room for improvement. Hence, a new design core power control is very important to improve the current performance in tracking and regulating reactor power by controlling the movement of control rods that suit the demand of highly sensitive of nuclear reactor power control. In this paper, the proposed Model Predictive Control (MPC) law was applied to control the core power. The model for core power control was based on mathematical models of the reactor core, MPC, and control rods selection algorithm. The mathematical models of the reactor core were based on point kinetics model, thermal hydraulic models, and reactivity models. The proposed MPC was presented in a transfer function model of the reactor core according to perturbations theory. The transfer function model-based predictive control (TFMPC) was developed to design the core power control with predictions based on a T-filter towards the real-time implementation of MPC on hardware. This paper introduces the sensitivity functions for TFMPC feedback loop to reduce the impact on the input actuation signal and demonstrates the behaviour of TFMPC in term of disturbance and noise rejections. The comparisons of both tracking and regulating performance between the conventional controller and TFMPC were made using MATLAB and analysed. In conclusion, the proposed TFMPC has satisfactory performance in tracking and regulating core power for controlling nuclear reactor with high reliability and safety.Keywords: core power control, model predictive control, PUSPATI TRIGA reactor, TFMPC
Procedia PDF Downloads 23113664 Effects of the Amount of Static Stretching on the Knee Isokinetic Muscle Strength
Authors: Chungyu Chen, Hui-Ju Chang, Pei-Shan Guo, Huei-Ling Jhan, Yi-Ping Lin
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The purpose of this study was to investigate the effect of the amount of acutely static stretching on muscular strength and power. There were 15 males, and 7 females recruited voluntarily as the participants in the study. The mean age, body height, and weight of participants were 23.4 ± 2.8 years old, 171.0 ± 7.2 cm, and 65.7 ± 8.7 kg, respectively. Participants were repeated to stretch hamstring muscles 2 or 6 30-s bouts randomly on a separate day spaced 5-7 days apart in a passive, static, sit-and-reach stretching exercise. Before and after acutely static stretching, the Biodex System 4 Pro was used to acquire the peak torque, power, total work, and range of motion for right knee under the loading of 180 deg/s. The 2 (test-retest) × 2 (number of stretches) repeated measures two-way analysis of variance were used to compare the parameters of muscular strength/power (α = .05). The results showed that the peak torque, power, and total work increased significantly after acutely passive static stretching (ps < .05) in flexor and extensor of knee. But there were no significant differences found between the 2 and 6 30-s bouts hamstring muscles stretching (ps > .05). It indicated that the performance of muscular strength and power in knee flexion and extension do not inhibit following the increase of amount of stretching.Keywords: knee, power, flexibility, strength
Procedia PDF Downloads 26913663 Unbalanced Distribution Optimal Power Flow to Minimize Losses with Distributed Photovoltaic Plants
Authors: Malinwo Estone Ayikpa
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Electric power systems are likely to operate with minimum losses and voltage meeting international standards. This is made possible generally by control actions provide by automatic voltage regulators, capacitors and transformers with on-load tap changer (OLTC). With the development of photovoltaic (PV) systems technology, their integration on distribution networks has increased over the last years to the extent of replacing the above mentioned techniques. The conventional analysis and simulation tools used for electrical networks are no longer able to take into account control actions necessary for studying distributed PV generation impact. This paper presents an unbalanced optimal power flow (OPF) model that minimizes losses with association of active power generation and reactive power control of single-phase and three-phase PV systems. Reactive power can be generated or absorbed using the available capacity and the adjustable power factor of the inverter. The unbalance OPF is formulated by current balance equations and solved by primal-dual interior point method. Several simulation cases have been carried out varying the size and location of PV systems and the results show a detailed view of the impact of PV distributed generation on distribution systems.Keywords: distribution system, loss, photovoltaic generation, primal-dual interior point method
Procedia PDF Downloads 32613662 Solar Panel Design Aspects and Challenges for a Lunar Mission
Authors: Mannika Garg, N. Srinivas Murthy, Sunish Nair
Abstract:
TeamIndus is only Indian team participated in the Google Lunar X Prize (GLXP). GLXP is an incentive prize space competition which is organized by the XPrize Foundation and sponsored by Google. The main objective of the mission is to soft land a rover on the moon surface, travel minimum displacement of 500 meters and transmit HD and NRT videos and images to the Earth. Team Indus is designing a Lunar Lander which carries Rover with it and deliver onto the surface of the moon with a soft landing. For lander to survive throughout the mission, energy is required to operate all attitude control sensors, actuators, heaters and other necessary components. Photovoltaic solar array systems are the most common and primary source of power generation for any spacecraft. The scope of this paper is to provide a system-level approach for designing the solar array systems of the lander to generate required power to accomplish the mission. For this mission, the direction of design effort is to higher efficiency, high reliability and high specific power. Towards this approach, highly efficient multi-junction cells have been considered. The design is influenced by other constraints also like; mission profile, chosen spacecraft attitude, overall lander configuration, cost effectiveness and sizing requirements. This paper also addresses the various solar array design challenges such as operating temperature, shadowing, radiation environment and mission life and strategy of supporting required power levels (peak and average). The challenge to generate sufficient power at the time of surface touchdown, due to low sun elevation (El) and azimuth (Az) angle which depends on Lunar landing site, has also been showcased in this paper. To achieve this goal, energy balance analysis has been carried out to study the impact of the above-mentioned factors and to meet the requirements and has been discussed in this paper.Keywords: energy balance analysis, multi junction solar cells, photovoltaic, reliability, spacecraft attitude
Procedia PDF Downloads 22313661 Microgrid: An Alternative of Electricity Supply to an Island in Thailand
Authors: Pawitchaya Srijaiwong, Surin Khomfoi
Abstract:
There are several solutions to supply electricity to an island in Thailand such as diesel generation, submarine power cable, and renewable energy power generation. However, each alternative has its own limitation like fuel and pollution of diesel generation, submarine power cable length resulting in loss of cable and cost of investment, and potential of renewable energy in the local area. This paper shows microgrid system which is a new alternative for power supply to an island. It integrates local power plant from renewable energy, energy storage system, and microgrid controller. The suitable renewable energy power generation on an island is selected from geographic location and potential evaluation. Thus, photovoltaic system and hydro power plant are taken into account. The capacity of energy storage system is also estimated by transient stability study in order to supply electricity demand sufficiently under normal condition. Microgrid controller plays an important role in conducting, communicating and operating for both sources and loads on an island so that its functions are discussed in this study. The conceptual design of microgrid operation is investigated in order to analyze the reliability and power quality. The result of this study shows that microgrid is able to operate in parallel with the main grid and in case of islanding. It is applicable for electricity supply to an island and a remote area. The advantages of operating microgrid on an island include the technical aspect like improving reliability and quality of power system and social aspects like outage cost saving and CO₂ reduction.Keywords: energy storage, islanding, microgrid, renewable energy
Procedia PDF Downloads 31913660 A ZVT-ZCT-PWM DC-DC Boost Converter with Direct Power Transfer
Authors: Naim Suleyman Ting, Yakup Sahin, Ismail Aksoy
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This paper presents a zero voltage transition-zero current transition (ZVT-ZCT)-PWM DC-DC boost converter with direct power transfer. In this converter, the main switch turns on with ZVT and turns off with ZCT. The auxiliary switch turns on and off with zero current switching (ZCS). The main diode turns on with ZVS and turns off with ZCS. Besides, the additional current or voltage stress does not occur on the main device. The converter has features as simple structure, fast dynamic response and easy control. Also, the proposed converter has direct power transfer feature as well as excellent soft switching techniques. In this study, the operating principle of the converter is presented and its operation is verified for 1 kW and 100 kHz model.Keywords: direct power transfer, boost converter, zero-voltage transition, zero-current transition
Procedia PDF Downloads 80613659 Critical Review of Clean Energy Mix as Means of Boosting Power Generation in Nigeria
Authors: B. Adebayo, A. A. Adebayo
Abstract:
Adequate power generation and supply are enormous challenges confronting Nigeria state today. This is a powerful mechanism that drives industrial development and socio-economy of any nation. The present level of power generation and supply have become national embarrassment to both government and the citizens of Nigeria, where over 60% of the population have no access to electricity. This paper is set to review the abundant clean energy alternative sources available in abundance that are capable of boosting power generation. The clean energy sources waiting to be exploited include: nuclear, solar and wind energy. The environmental benefits of these sources of power generation are identified. Nuclear energy is a powerful clean energy source. However, Africa accounted for 20% of known recoverable reserve and uranium produces heat of 500,000 MJ/kg. Moreover, Nigeria receives average daily solar radiation of over 5.249 kWh/m2/day. Researchers have shown that wind speed and power flux densities varied from 1.5 – 4.1 m/s and 5.7 – 22.5 W/m2 respectively. It is a fact that the cost of doing business in Nigeria is very high, leading to winding up of the multi-national companies and then led to increase unemployment level. More importantly, readily available vast quantity of energy will reduce cost of running industries. Hence, more industries will come on board, goods, services, and more job creation will be achieved. This clean source of power generation is devoid of production of green house gases, elimination of environmental pollution, and reduced waste disposal. Then Nigerians will live in harmony with the environment.Keywords: power, generation, energy, mix, clean, industrial
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