Search results for: harmonic components

Authors: Ji Young Lee, Jong Woon Kim

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It is essential to secure high availability of railway vehicles to realize high quality and efficiency of railway service. Once the availability decreased, planned railway service could not be provided or more cars need to be reserved. additional cars need to be purchased or the frequency of railway service could be decreased. Such situation would be a big loss in terms of quality and cost related to railway service. Therefore, we make various efforts to get high availability of railway vehicles. Because it is a big loss to operators, we make various efforts to get high availability of railway vehicles. To secure high availability, the idle time of the vehicle needs to be reduced and the following methods are applied to railway vehicles. First, through modularization design, exchange time for line replaceable units is reduced which makes railway vehicles could be put into the service quickly. Second, to reduce periodic preventive maintenance time, preventive maintenance with short period would be proceeded test oriented to minimize the maintenance time, and reliability is secured through overhauls for each main component. With such design changes for railway vehicles, modularized components are exchanged first at the time of vehicle failure or overhaul so that vehicles could be put into the service quickly and exchanged components are repaired or overhauled. Therefore, spare components are required for any future failures or overhauls. And, as components are modularized and costs for components are high, it is considerably important to get reasonable quantities of spare components. Especially, when a number of railway vehicles were put into the service simultaneously, the time of overhauls come almost at the same time. Thus, for some vehicles, components need to be exchanged and overhauled before appointed overhaul period so that these components could be secured as spare parts for the next vehicle’s component overhaul. For this reason, components overhaul time and spare parts quantities should be decided at the same time. This study deals with the time of overhauls for repairable components of railway vehicles and the calculation of spare parts quantities in consideration of future failure/overhauls. However, as railway vehicles are used according to the service schedule, maintenance work cannot be proceeded after the service was closed thus it is quite difficult to resolve this situation mathematically. In this study, Simulation software system is used in this study for analyzing the time of overhauls for repairable components of railway vehicles and the spare parts for the railway systems.

Keywords: overhaul time, rolling stocks, simulation, spare parts

Procedia PDF Downloads 336

Authors: Masoud Safarishaal

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Detecting the location of pole-to-earth faults is essential for the safe operation of the electrical system of the railroad. This paper aims to use a combination of evolutionary algorithms and neural networks to increase the accuracy of single pole-to-earth fault detection and location on the Tehran railroad power supply system. As a result, the Imperialist Competitive Algorithm (ICA) and Particle Swarm Optimization (PSO) are used to train the neural network to improve the accuracy and convergence of the learning process. Due to the system's nonlinearity, fault detection is an ideal application for the proposed method, where the 600 Hz harmonic ripple method is used in this paper for fault detection. The substations were simulated by considering various situations in feeding the circuit, the transformer, and typical Tehran metro parameters that have developed the silicon rectifier. Required data for the network learning process has been gathered from simulation results. The 600Hz component value will change with the change of the location of a single pole to the earth's fault. Therefore, 600Hz components are used as inputs of the neural network when fault location is the output of the network system. The simulation results show that the proposed methods can accurately predict the fault location.

Keywords: single pole-to-pole fault, Tehran railway, ICA, PSO, artificial neural network

Procedia PDF Downloads 122

Authors: Dandan Shen, Hui-zhu Wang, Xi Yu, LiLi Gui, Xiao Wei, Xiao-yan Jiang, Da-wei Wang, Min Hong

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Yu-ping-feng-san (YPFS) is a clinical medicine for asthma and other allergic diseases, but the mechanism of YPFS on relapse of allergy is unclear. Currently, people come to realize the epithelial cells(EC) play a key role in stimulating and regulating local immune response. The study of thymic stromal lymphopoietin（TSLP derived from EC provides an important evidence that the EC can regulate immune response to stimulate allergic response. In this study, we observed the effect of YPFS on TSLP in vivo and in vitro. We established a method by using bronchial epithelial cells (16HBE) for screening potential bioactive components by HPLC-MS in YPFS and then analyzed the components in serum containing YPFS by UPLC-MS. The results showed that YPFS could decrease TSLP protein level in OVA-sensitized mice and 16HBE cells. Five components combing with the 16HBE cells were both detected in the serum.

Keywords: TSLP, bronchial epithelial cells, cell-binding, drug-containing serum

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Authors: Gianni Blasi, Daniele Perrone, Maria Antonietta Aiello

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The seismic vulnerability of non-structural components is nowadays recognized to be a key issue in performance-based earthquake engineering. Recent loss estimation studies, as well as the damage observed during past earthquakes, evidenced how non-structural damage represents the highest rate of economic loss in a building and can be in many cases crucial in a life-safety view during the post-earthquake emergency. The procedures developed to evaluate the seismic demand on non-structural components have been constantly improved and recent studies demonstrated how the existing formulations provided by main Standards generally ignore features which have a sensible influence on the definition of the seismic acceleration/displacements subjecting non-structural components. Since the influence of the infills on the dynamic behaviour of RC structures has already been evidenced by many authors, it is worth to be noted that the evaluation of the seismic demand on non-structural components should consider the presence of the infills as well as their mechanical properties. This study focuses on the evaluation of time-history floor acceleration in RC buildings; which is a useful mean to perform seismic vulnerability analyses of non-structural components through the well-known cascade method. Dynamic analyses are performed on an 8-storey RC frame, taking into account the presence of the infills; the influence of the elastic modulus of the panel on the results is investigated as well as the presence of openings. Floor accelerations obtained from the analyses are used to evaluate the floor response spectra, in order to define the demand on non-structural components depending on the properties of the infills. Finally, the results are compared with formulations provided by main International Standards, in order to assess the accuracy and eventually define the improvements required according to the results of the present research work.

Keywords: floor spectra, infilled RC frames, non-structural components, seismic demand

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Authors: Hendradi Hardhienata, Tony Sumaryada, Sri Setyaningsih

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Current progress in the field of nonlinear optics has enabled precise surface characterization in semiconductor materials. Nonlinear optical techniques are favorable due to their nondestructive measurement and ability to work in nonvacuum and ambient conditions. The advance of the bond hyperpolarizability models opens a wide range of nanoscale surface investigation including the possibility to detect molecular orientation at the surface of silicon and zincblende semiconductors, investigation of electric field induced second harmonic fields at the semiconductor interface, detection of surface impurities, and very recently, study surface defects such as twin boundary in wurtzite semiconductors. In this work, we show using nonlinear optical techniques, e.g. nonlinear bond models how arbitrary polarization of the incoming electric field in Rotational Anisotropy Spectroscopy experiments can provide more information regarding the origin of the nonlinear sources in zincblende and wurtzite semiconductor structure. In addition, using hyperpolarizability consideration, we describe how the nonlinear susceptibility tensor describing SHG can be well modelled using only few parameter because of the symmetry of the bonds. We also show how the third harmonic intensity feature shows considerable changes when the incoming field polarization angle is changed from s-polarized to p-polarized. We also propose a method how to investigate surface reconstruction and defects in wurtzite and zincblende structure at the nanoscale level.

Keywords: surface characterization, bond model, rotational anisotropy spectroscopy, effective hyperpolarizability

Procedia PDF Downloads 157

Authors: Alitajer Saeed, Negintaji Farshad

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This study has been examined the relationship between anatomical components of mosques and place attachment of people to anatomies of mosques with the approach of attending to Islamic wisdom. To this end, this article by reviewing the theoretical and empirical literature of mosques' anatomy and the role of anatomy on the architectural design of Iranian mosques by examining the quantitative and qualitative indicators and in order to understand and identify the anatomy of mosques, components such as: entrance, portico, minarets, domes, bedchamber and pool have been investigated. For this purpose, SPSS software has been used. Research is related to field and is of descriptive, analytical and inferential type and quantitative and qualitative indicators have been examined. Statistical analysis obtained from the questionnaire indicates that there is a significant relationship between the anatomical components of architecture and place attachment of the participants. By understanding and identifying the anatomy of mosques and appropriate planning to use the anatomy in Islamic architecture and considering it as an eminent indicators of designing, it can present great Iranian architecture.

Keywords: Islamic wisdom, Islamic architecture, mosque anatomy place attachment, Islamic art

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Authors: Oguz Ugurkan Akkaya, Alpaslan Sipahi, Ozgur Firat Pamukcu, Murat Yasar, Tolga Guler, Arif Ulu, Ferit Cakir

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With the increase in human population, expansion, and renovation of cities, infrastructure systems today need to be manufactured to be more durable and long-lasting. The most cost-effective and durable manufacturing of components is a general problem of all engineering disciplines. Therefore, it is important to determine the most optimal components. This study mainly focuses on the most optimal component design of the polymer concrete. For this purpose, the lower and upper limits of the three main components of the polymer concrete are determined. The effects of these three principal components on the compressive strength, tensile strength, and unit price of polymer concrete are estimated using the response surface method. Box-Behnken Design is used in designing the experiments. Compressive strength, tensile strength, and unit prices are successfully estimated with variance ratios (R²) of 0.82, 0.92, and 0.90, respectively, and the optimum mixture quantity is determined.

Keywords: Box-Behnken Design, compressive strength, mechanical tests, polymer concrete, tensile strength

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Authors: Alireza Taghdiri, Sara Ghanbarzade Ghomi

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Nowadays, steel structures are used for not only common buildings but also high-rise construction and wide span covering. The advanced methods of construction as well as the advanced structural connections have a great effect on architecture. However a better use of steel structural systems will be achieved with the deep understanding of steel structures specifications and their substantial advantages. On the other hand, the steel structures face to the different environmental factors such as air flow which cause erosion and corrosion. With the time passing, the amount of these steel mass damages and also the imposed stress will be increased. In other words, the position of erosion in steel structures related to existing stresses indicates that effective environmental conditions will gradually decrease the structural resistance of steel components and result in decreasing the durability of steel components. In this paper, the durability of different steel structural components is evaluated and on the basis of these stress, architectural strategies for designing the system and the components of steel structures is recognized in order to achieve an optimum life cycle.

Keywords: durability, bending stress, erosion in steel structure, life cycle

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Authors: Fatemeh Nejati, Farah Habib, Sayeh Goudarzi

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Architecture and structure have always been closely interrelated so that they should be integrated into a unified, coherent and beautiful universe, while in the contemporary era, both structures and architecture proceed separately. The purpose of architecture is the art of creating form and space and order for human service, and the goal of the structural engineer is the transfer of loads to the structure, too. This research seeks to achieve the goal by looking at the relationship between the form of architecture and structure from its inception to the present day to the Global Identification and Management Plan. Finally, by identifying the main components of the design of the structure in interaction with the architectural form, an effective step is conducted in the Professional training direction and solutions to professionals. Therefore, after reviewing the evolution of structural and architectural coordination in various historical periods as well as how to reach the form of the structure in different times and places, components are required to test the components and present the final theory that one hundred to be tested in this regard. Finally, this research indicates the fact that the form of architecture and structure has an aesthetic link, which is influenced by a number of components that could be edited and has a regular order throughout history that could be regular. The research methodology is analytic, and it is comparative using analytical and matrix diagrams and diagrams and tools for conducting library research and interviewing.

Keywords: architecture, structural form, structural and architectural coordination, effective components, aesthetics

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Authors: Lucjan Setlak, Emil Ruda

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The subject of this paper is to review, comparative analysis and simulation of selected components of power electronic systems (PES), consistent with the concept of a more electric aircraft (MEA). Comparative analysis and simulation in software environment MATLAB / Simulink were carried out based on a group of representatives of civil aircraft (B-787, A-380) and military (F-22 Raptor, F-35) in the context of multi-pulse converters used in them (6- and 12-pulse, and 18- and 24-pulse), which are key components of high-tech electronics on-board power systems of autonomous power systems (ASE) of modern aircraft (airplanes of the future).

Keywords: converters, electric machines, MEA (more electric aircraft), PES (power electronics systems)

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Authors: H. Mousavi, M. Sharifi, H. Pourvaziri

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Redundancy Allocation Problem (RAP) is a well-known mathematical problem for modeling series-parallel systems. It is a combinatorial optimization problem which focuses on determining an optimal assignment of components in a system design. In this paper, to be more practical, we have considered the problem of redundancy allocation of series system with interval valued reliability of components. Therefore, during the search process, the reliabilities of the components are considered as a stochastic variable with a lower and upper bounds. In order to optimize the problem, we proposed a simulated annealing based on cloud theory (CBSAA). Also, the Monte Carlo simulation (MCS) is embedded to the CBSAA to handle the random variable components’ reliability. This novel approach has been investigated by numerical examples and the experimental results have shown that the CBSAA combining MCS is an efficient tool to solve the RAP of systems with interval-valued component reliabilities.

Keywords: redundancy allocation problem, simulated annealing, cloud theory, monte carlo simulation

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Authors: Abeer Toheed Quadri, Maria Abubakar, Mehreen Sirshar

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Component Based Software Development (CBSD) is a new trend in software development. Selection of quality components is not enough to ensure software quality in Component Based Software System (CBSS). A software product is considered to be a quality product if it satisfies its customer’s needs and has minimum defects. Authors’ survey different research papers and analyzes various techniques which ensure software quality in component based software development. This paper includes an investigation about how to improve the quality of a component based software system without effecting quality attributes. The reported information is identified from literature survey. The developments of component based systems are rising as they reduce the development time, effort and cost by means of reuse. After analysis, it has been explored that in order to achieve the quality in a CBSS we need to have the components that are certified through software measure because the predictability of software quality attributes of system depend on the quality attributes of the constituent components, integration process and the framework used.

Keywords: CBSD (component based software development), CBSS (component based software system), quality components, SQA (software quality assurance)

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Authors: Fadilah Fadilah, Rochmadi Rochmadi, Siti Syamsiah, Djagal W. Marseno

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Glucomannan can be found in the tuber of porang together with starch and proteinaceous components which were regarded as impurities. An enzymatic process for obtaining higher glucomannan content from Porang flour have been conducted. Papain was used for hydrolysing proteinaceous components in Porang flour which was conducted after a simultaneous extraction of glucomannan and enzymatic starch hydrolysis. Three variables affecting the rate were studied, i.e. temperature, the amount of enzyme and the stirring speed. The ninhydrin method was used to determine degree of protein hydrolysis. Results showed that the rising of degree of hydrolysis were fast in the first ten minutes of the reaction and then proceeded slowly afterward. The optimum temperature for hydrolysis was 60 ^oC. Increasing the amount of enzyme showed a remarkable effect to degree of hydrolysis, but the stirring speed had no significant effect. This indicated that the reaction controlled the rate of hydrolysis.

Keywords: degree of hydrolysis, ninhydrin, papain, porang flour, proteinaceous components

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Authors: I. Gahlouz, A. Chellil

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The paper concerns the estimation of system components faults by using an unknown inputs observer. To reach this goal, we used the Bond Graph approach to physical modelling. We showed that this graphical tool is allowing the representation of system components faults as unknown inputs within the state representation of the considered physical system. The study of the causal and structural features of the system (controllability, observability, finite structure, and infinite structure) based on the Bond Graph approach was hence fulfilled in order to design an unknown inputs observer which is used for the system component fault estimation.

Keywords: estimation, bond graph, controllability, observability

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Authors: A. Ozkose

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This study was conducted to determination of yield and yield components of some fodder beet types (Amarilla Barres, Feldherr, Kyros, Magnum, and Rota) under the Konya region conditions. Fodder beet was obtained from the Selcuk University, Faculty of Agriculture, at 2006-2007 season and the experiment was established in a randomized complete block design with three replicates. Differences among the averages of the fodder beet cultivars are statistically important in terms of all the characteristics investigated. Leaf attitude value was 1.2–2.2 (1=erect; 5= prostrate), root shape scale value was (1=spheroidal – 9=cylindrical), root diameter 11.0–12.2 cm, remaining part of root on the ground was 6.3–13.7 cm, root length was 21.4 – 29.6 cm, leaf yield 1592 – 1917 kg/da, root yield was 10083–12258 kg/da, root dry matter content was %8.2– 18.6 and root dry matter yield was 889–1887 kg/da. As a result of the study, it was determined that fodder beet cultivars are different conditions in terms of yield and yield components. Therefore, determination of appropriate cultivars for each region affect crop yield importantly.

Keywords: fedder beet, root yield, yield components, Konya, agriculture

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Authors: Manel Hammami, Gabriele Grandi

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In recent years, multilevel inverters have become more attractive for single-phase photovoltaic (PV) systems, due to their known advantages over conventional H-bridge pulse width-modulated (PWM) inverters. They offer improved output waveforms, smaller filter size, lower total harmonic distortion (THD), higher output voltages and others. The most common multilevel converter topologies, presented in literature, are the neutral-point-clamped (NPC), flying capacitor (FC) and Cascaded H-Bridge (CHB) converters. In both NPC and FC configurations, the number of components drastically increases with the number of levels what leads to complexity of the control strategy, high volume, and cost. Whereas, increasing the number of levels in case of the cascaded H-bridge configuration is a flexible solution. However, it needs isolated power sources for each stage, and it can be applied to PV systems only in case of PV sub-fields. In order to improve the ratio between the number of output voltage levels and the number of components, several hybrids and asymmetric topologies of multilevel inverters have been proposed in the literature such as the FC asymmetric H-bridge (FCAH) and the NPC asymmetric H-bridge (NPCAH) topologies. Another asymmetric multilevel inverter configuration that could have interesting applications is the cascaded asymmetric H-bridge (CAH), which is based on a modular half-bridge (two switches and one capacitor, also called level doubling network, LDN) cascaded to a full H-bridge in order to double the output voltage level. This solution has the same number of switches as the above mentioned AH configurations (i.e., six), and just one capacitor (as the FCAH). CAH is becoming popular, due to its simple, modular and reliable structure, and it can be considered as a retrofit which can be added in series to an existing H-Bridge configuration in order to double the output voltage levels. In this paper, an original and effective method for the analysis of the DC-link voltage ripple is given for single-phase asymmetric H-bridge multilevel inverters based on level doubling network (LDN). Different possible configurations of the asymmetric H-Bridge multilevel inverters have been considered and the analysis of input voltage and current are analytically determined and numerically verified by Matlab/Simulink for the case of cascaded asymmetric H-bridge multilevel inverters. A comparison between FCAH and the CAH configurations is done on the basis of the analysis of the DC and voltage ripple for the DC source (i.e., the PV system). The peak-to-peak DC and voltage ripple amplitudes are analytically calculated over the fundamental period as a function of the modulation index. On the basis of the maximum peak-to-peak values of low frequency and switching ripple voltage components, the DC capacitors can be designed. Reference is made to unity output power factor, as in case of most of the grid-connected PV generation systems. Simulation results will be presented in the full paper in order to prove the effectiveness of the proposed developments in all the operating conditions.

Keywords: asymmetric inverters, dc-link voltage, level doubling network, single-phase multilevel inverter

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Authors: Saad M. Howladar, Mike Dennett

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At first harvest, results showed that salinity (tap water, 100 and 200 mM NaCl) induced a significant decrease in all growth parameters in both Yecora Rojo and Paragon cultivars. The greatest effect of salinity was a decrease in leaf area. The same tendency was observed with specific leaf area, and total fresh and dry weights and their components. Green leaf and tiller numbers were reduced by the same extent in both cultivars. The corresponding final harvest, all growth parameters also reduced with increased salinity. Yield and yield components were also reduced by salinity with similar effects in both cultivars. Chlorophyll fluorescence, expressed as Fv/Fm, and gas exchange parameters were decreased significantly with increase in salinity in both cultivars. In contrast, seed protein content was increased significantly with increase in salinity. Salicylic acid (SA) application induced no significant improvements in growth parameters and yield components.

Keywords: salinity, salicylic acid, growth, chlorophyll fluorescence, gas exchange, yield

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Authors: Maximilian Winkens, Peter Nyhuis

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Components with sensory properties such as gentelligent components developed at the Collaborative Research Center 653 offer a new angle on the full utilization of the remaining service life in case of a preventive maintenance. The developed methodology of component status driven maintenance analyses the stress data obtained during the component's useful life and on the basis of this knowledge assesses the type of maintenance called for in this case. The procedure is derived from the case-based reasoning method and will be elucidated in detail. The method's functionality is demonstrated with real-life data obtained during test runs of a racing car prototype.

Keywords: gentelligent component, preventive maintenance, case-based reasoning, sensory

Procedia PDF Downloads 362

Authors: Saad Howladar, Mike Dennett

Abstract:

At first harvest, results showed that salinity (tap water, 100 and 200 mM NaCl) induced a significant decrease in all growth parameters in both Yecora Rojo and Paragon cultivars. The greatest effect of salinity was a decrease in leaf area. The same tendency was observed with specific leaf area, and total fresh and dry weights and their components. Green leaf and tiller numbers were reduced by the same extent in both cultivars. The corresponding final harvest, all growth parameters also reduced with increased salinity. Yield and yield components were also reduced by salinity with similar effects in both cultivars. Chlorophyll fluorescence, expressed as Fv/Fm, and gas exchange parameters were decreased significantly with increase in salinity in both cultivars. In contrast, seed protein content was increased significantly with increase in salinity. Salicylic acid (SA) application induced no significant improvements in growth parameters and yield components.

Keywords: salinity, salicylic acid, growth, chlorophyll fluorescence, gas exchange, yield

Procedia PDF Downloads 422

Authors: Radhey Sham Rajoria

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Pressure to increase the competitiveness in the manufacturing sector and for the survival in the market has led to the development of machining centres, which enhance productivity, improve quality, shorten the lead time, and reduce the manufacturing cost. With the innovation of machining centres in the manufacturing sector the production lines have been replaced by these machining centers, having the ability to machine various processes and multiple tooling with automatic tool changer (ATC) for the same part. Also the process plans can be easily generated for complex components. Some means are required to utilize the machining center at its best. The present work is concentrated on the automated part program generation, and in turn automated process plan generation for the turned components on Denford “MIRAC” 8 stations ATC lathe machining centre. A package in C++ on DOS platform is developed which generates the complete CNC part program, process plan and process sequence for the turned components. The input to this system is in the form of a blueprint in graphical format with machining parameters and variables, and the output is the CNC part program which is stored in a .mir file, ready for execution on the machining centre.

Keywords: CNC, MIRAC, ATC, process planning

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Authors: N. Benkhettoua, Y. Barkata

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We present first-principles studies of structural and thermodynamic properties of MnNi According to the calculated total energies, by using an all-electron full-potential linear muffin–tin orbital method (FP-LMTO) within LDA and the quasi-harmonic Debye model implemented in the Gibbs program is used for the temperature effect on structural and calorific properties.

Keywords: magnetic materials, structural properties, thermodynamic properties, metallurgical and materials engineering

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Authors: A. Majidian

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The life prediction of thermal power plant components is necessary to prevent the unexpected outages, optimize maintenance tasks in periodic overhauls and plan inspection tasks with their schedules. One of the main critical components in a power plant is condenser because its failure can affect many other components which are positioned in downstream of condenser. This paper deals with factors affecting life of condenser. Failure rates dependency vs. these factors has been investigated using Artificial Neural Network (ANN) and fuzzy logic algorithms. These algorithms have shown their capabilities as dynamic tools to evaluate life prediction of power plant equipments.

Keywords: life prediction, condenser tube, neural network, fuzzy logic

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Authors: Bharat Kumar, Deepak Kumar, Vijay Chaudhry

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Zirconium alloys are used as core components of nuclear reactors due to their high wear resistance, good corrosion properties, and good mechanical stability at high temperatures. Water flows inside the pressure tube through fuel claddings, which produces vibration of these core components and results in the wear of some components. Some components are subjected to the environment of coolant water containing LiOH which results in the corrosion of these components. The present work simulates some of these conditions to determine the failure mechanisms under these conditions and the effect of various parameters on them. Friction and wear experiments were performed varying the surrounding environment (room temperature, high temperature, and water submerged), duration, frequency, and displacement amplitude. Electrochemical corrosion experiments were performed by varying the concentration of LiOH in water. The worn and corroded surfaces were analyzed using scanning electron microscopy (SEM) to analyze the wear and corrosion mechanism and energy dispersive x-ray spectroscopy (EDS) and Raman spectroscopy to analyze the tribo-oxide layer formed during the wear and oxide layer formed during the corrosion. Wear increases with frequency and amplitude, and corrosion increases with LiOH concentration in water.

Keywords: zirconium alloys, wear, oxide layer, corrosion, EIS, linear polarization

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Authors: Ali Albadri

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Step band in an escalator moves in a cyclic periodic pattern. Similarly, most if not all of the components and sub-assemblies in the escalator operate in the same way. If you mark up one step in the step band of an escalator and stand next to the escalator, on the incline, to watch the marked-up step when it passes by, you ask yourself, does the marked up step behaves exactly the same way during each revolution when it passes you by again and again? We can say that; there is some similarity in this example and the example when an astronomer watches planets in the sky, and he or she asks himself or herself, does each planet intersects the plan of observation in the same position for every pantry rotation? For a fact, we know for the answer to the second example is no, because scientist, astronomers, and mathematicians have proven that planets deviate from their paths to take new paths during their planetary moves, albeit with minimal change. But what about the answer to the question in the first example? considering that there is increase in the wear and tear of components with time in the step, in the step band, in the tracks and in many other places in the escalator. There is also the accumulation of fatigue in the components and sub-assemblies. This research is part of many studies which we are conducting to address the answer for the question in the first example. We have been using the fractal dimension as a quantities tool and the Poincare map as a qualitative tool. This study has shown that the fractal dimension value and the shape and distribution of the orbits in the Poincare map has significant correlation with the quality of the mechanical components and sub-assemblies in the escalator.

Keywords: fractal dimension, Poincare map, rugby ball orbit, worm orbit

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Authors: M. Cangi, T. Dolar, C. Ersoy, Y. E. Aydogdu, A. I. Aydeniz, A. Mugan

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The drum is one of the critical parts in a washing machine in which the clothes are washed and spin by the rotational movement. It is activated by the drum shaft which is attached to an electric motor and subjected to dynamic loading. Being one of the critical components, failures of the drum require costly repairs of dynamic components. In this study, tolerance bands between the drum shaft and its two bearings were examined to develop a relationship between the fatigue life of the shaft and the interaction tolerances. Optimization of tolerance bands was completed in consideration of the fatigue life of the shaft as the cost function. The following methodology is followed: multibody dynamic model of a washing machine was constructed and used to calculate dynamic loading on the components. Then, these forces were used in finite element analyses to calculate the stress field in critical components which was used for fatigue life predictions. The factors affecting the fatigue life were examined to find optimum tolerance grade for a given test condition. Numerical results were verified by experimental observations.

Keywords: fatigue life, finite element analysis, tolerance analysis, optimization

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Authors: Mehranoosh Gholipoor

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The effects of planting date on performance and yield components of maize single cross 704 was carried out in 2003.this experiment was designed in randomized complete block pattern with 3 replications in the field of College campus of Agricultural Sciences and Natural Resources in Gorgan. Treatments consisted of four planting dates (May5, May19, June4 and June19) respectively. The results showed that the planting on June4 were the best time for planting date in the field of seed performance and many other measurement qualities while planting date on June19 had the lowest seed performance in corn, due to a severe reduction in seed numbers had the highest In 1000 seed weight. Between the planting date on May 5 and May19 were observed no significant differences

Keywords: corn, planting date, performance and yield components

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Authors: Raheela Akhtar, Zafar Iqbal Chaudhary, Yongqun Oliver He, Muhammad Younus, Aftab Ahmad Anjum

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Brucella abortus is an intracellular pathogen affecting macrophages. Macrophages release some components such as lysozymes (LZ), reactive oxygen species (ROS) and reactive nitrite intermediates (RNI) which are important tools against intracellular survival of Brucella. The antibrucella activity of bovine and murine macrophages was compared following stimulation with Brucella abortus lipopolysaccharides. Our results revealed that murine macrophages were ten times more potent to produce antibrucella components than bovine macrophages. The differential production of these components explained the differential Brucella killing ability of these species that was measured in terms of intramacrophagic survival of Brucella in murine and bovine macrophages.

Keywords: bovine macrophages, Brucella abortus, cell stimulation, cytokines, Murine macrophages

Procedia PDF Downloads 558

Authors: Maryam Ghasemi

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One of the most significant components that provide comfort and protection is having a shelter called a house. Even if components and regions are changed or restored to meet new functions, the house's identity must be preserved. In the contemporary era, houses are increasingly being built regardless of cultural identity. This misunderstanding caused a sense of unease. This study analyses archaic and modern architecture to find semiotic areas and qualities in the latter, using the former as a reference. This study's technique used an exploratory assessment of architectural components from both periods. The Abbasid residence and the Ekbatan architectural complex were used as case studies. The identity of Iranian architecture does not correlate with current buildings. The other part is privacy, which is a missing link between traditional and modern Iranian architecture because it is directly related to the identities of homes based on the cultures of their residents.

Keywords: housing, traditional, contemporary, privacy, semiotic

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Authors: Cuong D. Dao, Rob J.I. Basten, Andreas Hartmann

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This paper studies the optimal maintenance planning of preventive maintenance and renewal activities for components in a single railway track when the available time for maintenance is limited. The rail-track system consists of several types of components, such as rail, ballast, and switches with different preventive maintenance and renewal intervals. To perform maintenance or renewal on the track, a train free period for maintenance, called a possession, is required. Since a major possession directly affects the regular train schedule, maintenance and renewal activities are clustered as much as possible. In a highly dense and utilized railway network, the possession time on the track is critical since the demand for train operations is very high and a long possession has a severe impact on the regular train schedule. We present an optimization model and investigate the maintenance schedules with and without the possession capacity constraint. In addition, we also integrate the social-economic cost related to the effects of the maintenance time to the variable possession cost into the optimization model. A numerical example is provided to illustrate the model.

Keywords: rail-track components, maintenance, optimal clustering, possession capacity

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Authors: Manikandakumar Shunmugavel, Ashwin Polishetty, Moshe Goldberg, Junior Nomani, Guy Littlefair

Abstract:

Selective laser melting (SLM), a promising additive manufacturing (AM) technology, has a huge potential in the fabrication of Ti-6Al-4V near-net shape components. However, poor surface finish of the components fabricated from this technology requires secondary machining to achieve the desired accuracy and tolerance. Therefore, a systematic understanding of the machinability of SLM fabricated Ti-6Al-4V components is paramount to improve the productivity and product quality. Considering the significance of machining in SLM fabricated Ti-6Al-4V components, this research aim is to study the influence of build orientation on machinability characteristics by performing low speed orthogonal cutting tests. In addition, the machinability of SLM fabricated Ti-6Al-4V is compared with conventionally produced wrought Ti-6Al-4V to understand the influence of SLM technology on machining. This paper is an attempt to provide evidence to the hypothesis associated that build orientation influences cutting forces, chip formation and surface integrity during orthogonal cutting of SLM Ti-6Al-4V samples. Results obtained from the low speed orthogonal cutting tests highlight the practical importance of microstructure and build orientation on machinability of SLM Ti-6Al-4V.

Keywords: additive manufacturing, build orientation, machinability, titanium alloys (Ti-6Al-4V)

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