Search results for: film cooling effectiveness
1462 A Reproduction of Boundary Conditions in Three-Dimensional Continuous Casting Problem
Authors: Iwona Nowak, Jacek Smolka, Andrzej J. Nowak
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The paper discusses a 3D numerical solution of the inverse boundary problem for a continuous casting process of alloy. The main goal of the analysis presented within the paper was to estimate heat fluxes along the external surface of the ingot. The verified information on these fluxes was crucial for a good design of a mould, effective cooling system and generally the whole caster. In the study an enthalpy-porosity technique implemented in Fluent package was used for modeling the solidification process. In this method, the phase change interface was determined on the basis of the liquid fraction approach. In inverse procedure the sensitivity analysis was applied for retrieving boundary conditions. A comparison of the measured and retrieved values showed a high accuracy of the computations. Additionally, the influence of the accuracy of measurements on the estimated heat fluxes was also investigated.
Keywords: Boundary inverse problem, sensitivity analysis, continuous casting, numerical simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15291461 Air flow and Heat Transfer Modeling of an Axial Flux Permanent Magnet Generator
Authors: Airoldi G., Bumby J. R., Dominy C., G.L. Ingram, Lim C. H., Mahkamov K., N. L. Brown, A. Mebarki, M. Shanel
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Axial Flux Permanent Magnet (AFPM) Machines require effective cooling due to their high power density. The detrimental effects of overheating such as degradation of the insulation materials, magnets demagnetization, and increase of Joule losses are well known. This paper describes the CFD simulations performed on a test rig model of an air cooled Axial Flux Permanent Magnet (AFPM) generator built at Durham University to identify the temperatures and heat transfer coefficient on the stator. The Reynolds Averaged Navier-Stokes and the Energy equations are solved and the flow pattern and heat transfer developing inside the machine are described. The Nusselt number on the stator surfaces has been found. The dependency of the heat transfer on the flow field is described temperature field obtained. Tests on an experimental are undergoing in order to validate the CFD results.
Keywords: Axial flux permanent magnet machines, thermal modeling, CFD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23141460 Hydrogen Sensor Based on Surface Activated WO3 Films by Pd Nanoclusters
Authors: S.Fardindoost, A. Iraji Zad, S.M.Mahdavi
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Tungsten trioxide has been prepared by using P-PTA as a precursor on alumina substrates by spin coating method. Palladium introduced on WO3 film via electrolysis deposition by using palladium chloride as catalytic precursor. The catalytic precursor was introduced on the series of films with different morphologies. X-ray diffractometry (XRD), Scanning electron microscopy (SEM) and XPS were applied to analyze structure and morphology of the fabricated thin films. Then we measured variation of samples- electrical conductivity of pure and Pd added films in air and diluted hydrogen. Addition of Pd resulted in a remarkable improvement of the hydrogen sensing properties of WO3 by detection of Hydrogen below 1% at room temperature. Also variation of the electrical conductivity in the presence of diluted hydrogen revealed that response of samples depends rather strongly on the palladium configuration on the surface.Keywords: Electrolysis, Hydrogen sensing, Palladium, WO3
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21921459 The Effect of Molybdate on Corrosion Behaviour of AISI 316Ti Stainless Steel in Chloride Environment
Authors: Viera Zatkalíková, Lenka Markovičová, Aneta Tor-Swiatek
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The effect of molybdate addition to chloride environment on resistance of AISI 316Ti stainless steel to pitting corrosion was studied. Potentiodynamic polarisation tests were performed in 1 M and 0.1 M chloride acidified solutions with various additions of sodium molybdate at room temperature. The presented results compare the effect of molybdate anions on quality of passive film (expressed by the pitting potential) in both chloride solutions. The pitting potential increases with the increase inhibitor concentration. The inhibitive effect of molybdate ions is stronger in chloride solution of lower aggressiveness (0.1M).
Keywords: AISI 316Ti steel, molybdate inhibitor, pitting corrosion, pitting potential, potentiodynamic polarization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21891458 Investigation of Solvent Effect on Viscosity of Lubricant in Disposable Medical Devices
Authors: Hamed Bagheri, Seyd Javid Shariati
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The effects of type and amount of solvent on lubricant which is used in disposable medical devices are investigated in this article. Two kinds of common solvent, n-Hexane and n-Heptane, are used. The mechanical behavior of syringe has shown that n-Heptane has better mixing ratio and also more effective spray process in the barrel of syringe than n-Hexane because of similar solubility parameter to silicon oil. The results revealed that movement of plunger in the barrel increases when pure silicone is used because non-uniform film is created on the surface of barrel, and also, it seems that the form of silicon is converted from oil to gel due to sterilization process. The results showed that the convenient mixing ratio of solvent/lubricant oil is 80/20.
Keywords: Disposable medical devices, lubricant oil, solvent effect, solubility parameter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13941457 Obfuscation Studio Executive
Authors: Siarhei Petryk, Vyacheslav Yarmolik
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New software protection product called “Obfuscation Studio" is presented in the paper. Several obfuscating modules that are already implemented are described. Some theoretical data is presented, that shows the potency and effectiveness of described obfuscation methods. “Obfuscation Studio" is being implemented for protecting programs written for .NET platform, but the described methods can also be interesting for other applications.Keywords: Coupling, obfuscation, predicates, renaming.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11821456 Solving the Nonlinear Heat Conduction in a Spherical Coordinate with Electrical Simulation
Authors: A. M. Gheitaghy, H. Saffari, G. Q. Zhang
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Numerical approach based on the electrical simulation method is proposed to solve a nonlinear transient heat conduction problem with nonlinear boundary for a spherical body. This problem represents a strong nonlinearity in both the governing equation for temperature dependent thermal property and the boundary condition for combined convective and radiative cooling. By analysing the equivalent electrical model using the electrical circuit simulation program HSPICE, transient temperature and heat flux distributions at sphere can be obtained easily and fast. The solutions clearly illustrate the effect of the radiation-conduction parameter Nrc, the Biot number and the linear coefficient of temperature dependent conductivity and heat capacity. On comparing the results with corresponding numerical solutions, the accuracy and efficiency of this computational method is found to be good.Keywords: Convective boundary, radiative boundary, electrical simulation method, nonlinear heat conduction, spherical coordinate.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13921455 The Effects of Logistical Centers Realization on Society and Economy
Authors: Anna Dolinayova, Juraj Camaj, Martin Loch
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Presently, it is necessary to ensure the sustainable development of passenger and freight transport. Increasing performance of road freight has had a negative impact to environment and society. It is therefore necessary to increase the competitiveness of intermodal transport, which is more environmentally friendly. The study describes the effectiveness of logistical centers realization for companies and society and research how the partial internalization of external costs reflected in the efficient use of these centers and increase the competitiveness of intermodal transport to road freight. In our research, we use the method of comparative analysis and market research to describe the advantages of logistic centers for their users as well as for society as a whole. Method normal costing is used for calculation infrastructure and total costs, method of conversion costing for determine the external costs. We modelled total society costs for road freight transport and inter modal transport chain (we assumed that most of the traffic is carried by rail) with different loading schemes for condition in the Slovak Republic. Our research has shown that higher utilization of inter modal transport chain do good not only for society, but for companies providing freight services too. Increase in use of inter modal transport chain can bring many benefits to society that do not bring direct immediate financial return. They often bring the multiplier effects, such as greater use of environmentally friendly transport mode and reduce the total society costs.
Keywords: Delivery time, economy effectiveness, logistical centers, ecological efficiency, optimization, society.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20441454 Ear Protectors and Their Action in Protecting Hearing System of Workers against Occupational Noise
Authors: F. Forouharmajd, S. Pourabdian, N. Ziayi Ghahnavieh
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For many years, the ear protectors have been used to preventing the audio and non-audio effects of received noise from occupation environments. Despite performing hearing protection programs, there are many people which still suffer from noise-induced hearing loss. This study was conducted with the aim of determination of human hearing system response to received noise and the effectiveness of ear protectors on preventing of noise-induced hearing loss. Sound pressure microphones were placed in a simulated ear canal. The severity of noise measured inside and outside of ear canal. The noise reduction values due to installing ear protectors were calculated in the octave band frequencies and LabVIEW programmer. The results of noise measurement inside and outside of ear canal showed a different in received sound levels by ear canal. The effectiveness of ear protectors has been considerably reduced for the low frequency limits. A change in resonance frequency also was observed after using ear protectors. The study indicated the ear canal structure may affect the received noise and it may lead a difference between the received sound from the measured sound by a sound level meter, and hearing system. It means the human hearing system may probably respond different from a sound level meter. Hearing protectors’ efficiency declines by increasing the noise levels, and thus, they are not suitable to protect workers against industrial noise particularly low frequency noise. Hearing protectors may be solely a reason to damaging of hearing system in a special frequency via changing of human hearing system acoustical structure. We need developing the subjective method of hearing protectors testing, because their evaluation is not designed based on industrial noise or in the field.
Keywords: Ear protector, hearing system, occupational noise, workers.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7631453 Genetic Algorithm Optimization of a Small Scale Natural Gas Liquefaction Process
Authors: M. I. Abdelhamid, A. O. Ghallab, R. S. Ettouney, M. A. El-Rifai
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An optimization scheme based on COM server is suggested for communication between Genetic Algorithm (GA) toolbox of MATLAB and Aspen HYSYS. The structure and details of the proposed framework are discussed. The power of the developed scheme is illustrated by its application to the optimization of a recently developed natural gas liquefaction process in which Aspen HYSYS was used for minimization of the power consumption by optimizing the values of five operating variables. In this work, optimization by coupling between the GA in MATLAB and Aspen HYSYS model of the same process using the same five decision variables enabled improvements in power consumption by 3.3%, when 77% of the natural gas feed is liquefied. Also on inclusion of the flow rates of both nitrogen and carbon dioxide refrigerants as two additional decision variables, the power consumption decreased by 6.5% for a 78% liquefaction of the natural gas feed.
Keywords: Stranded gas liquefaction, genetic algorithm, COM server, single nitrogen expansion, carbon dioxide pre-cooling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15251452 Evaluating the Performance of Offensive Lineman in the NFL
Authors: Nikhil Byanna, Abdolghani Ebrahimi, Diego Klabjan
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In this paper we objectively measure the performance of an individual offensive lineman in the NFL. The existing literature proposes various measures that rely on subjective assessments of game film, but has yet to develop an objective methodology to evaluate performance. Using a variety of statistics related to an offensive lineman’s performance, we develop a framework to objectively analyze the overall performance of an individual offensive lineman and determine specific linemen who are overvalued or undervalued relative to their salary. We identify eight players across the 2013-2014 and 2014-2015 NFL seasons that are considered to be overvalued or undervalued and corroborate the results with existing metrics that are based on subjective evaluation. To the best of our knowledge, the techniques set forth in this work have not been utilized in previous works to evaluate the performance of NFL players at any position, including offensive linemen.
Keywords: offensive lineman, player performance, NFL, machine learning
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5381451 The Energy Impacts of Using Top-Light Daylighting Systems for Academic Buildings in Tropical Climate
Authors: M. S. Alrubaih, M. F. M. Zain, N. L. N. Ibrahim, M.A. Alghoul, K. I. Ben Sauod
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Careful design and selection of daylighting systems can greatly help in reducing not only artificial lighting use, but also decrease cooling energy consumption and, therefore, potential for downsizing air-conditioning systems. This paper aims to evaluate the energy performance of two types of top-light daylighting systems due to the integration of daylight together with artificial lighting in an existing examinaton hall in University Kebangsaan Malaysia, based on a hot and humid climate. Computer simulation models have been created for building case study (base case) and the two types of toplight daylighting designs for building energy performance evaluation using the VisualDOE 4.0 building energy simulation program. The finding revealed that daylighting through top-light systems is a very beneficial design strategy in reducing annual lighting energy consumption and the overall total annual energy consumption.
Keywords: Academic buildings, Daylighting, Top-lighting, Energy savings, Tropical Climate
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19491450 Effect of Elevation and Wind Direction on Silicon Solar Panel Efficiency
Authors: Abdulrahman M. Homadi
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As a great source of renewable energy, solar energy is considered to be one of the most important in the world, since it will be one of solutions cover the energy shortage in the future. Photovoltaic (PV) is the most popular and widely used among solar energy technologies. However, PV efficiency is fairly low and remains somewhat expensive. High temperature has a negative effect on PV efficiency and cooling system for these panels is vital, especially in warm weather conditions. This paper presents the results of a simulation study carried out on silicon solar cells to assess the effects of elevation on enhancing the efficiency of solar panels. The study included four different terrains. The study also took into account the direction of the wind hitting the solar panels. To ensure the simulation mimics reality, six silicon solar panels are designed in two columns and three rows, facing to the south at an angle of 30 o. The elevations are assumed to change from 10 meters to 200 meters. The results show that maximum increase in efficiency occurs when the wind comes from the north, hitting the back of the panels.Keywords: Solar panels, elevation, wind direction, efficiency.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23711449 Effects of Photovoltaic System Introduction in Detached Houses with All-Electrified Residential Equipment in Japan
Authors: Qingrong Liu, Tetsuo Hayashi, Yuji Ryu
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In this paper, in order to investigate the effects of photovoltaic system introduction to detached houses in Japan, two kinds of works were done. Firstly, the hourly generation amount of a 4.2kW photovoltaic system were simulated in 46 cities to investigate the potential of the system in different regions in Japan using a simulation model of photovoltaic system. Secondly, based on the simulated electricity generation amount, the energy saving, the environmental and the economic effect of the photovoltaic system were examined from hourly to annual timescales, based upon calculations of typical electricity, heating, cooling and hot water supply load profiles for Japanese dwellings. The above analysis was carried out using a standard year-s hourly weather data for the different city provided by the Expanded AMeDAS Weather Data issued by AIJ (Architectural Institute of Japan).Keywords: Photovoltaic system, Energy saving, Environmental effect, Japanese dwelling, Detached house.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13701448 Effective Stacking of Deep Neural Models for Automated Object Recognition in Retail Stores
Authors: Ankit Sinha, Soham Banerjee, Pratik Chattopadhyay
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Automated product recognition in retail stores is an important real-world application in the domain of Computer Vision and Pattern Recognition. In this paper, we consider the problem of automatically identifying the classes of the products placed on racks in retail stores from an image of the rack and information about the query/product images. We improve upon the existing approaches in terms of effectiveness and memory requirement by developing a two-stage object detection and recognition pipeline comprising of a Faster-RCNN-based object localizer that detects the object regions in the rack image and a ResNet-18-based image encoder that classifies the detected regions into the appropriate classes. Each of the models is fine-tuned using appropriate data sets for better prediction and data augmentation is performed on each query image to prepare an extensive gallery set for fine-tuning the ResNet-18-based product recognition model. This encoder is trained using a triplet loss function following the strategy of online-hard-negative-mining for improved prediction. The proposed models are lightweight and can be connected in an end-to-end manner during deployment to automatically identify each product object placed in a rack image. Extensive experiments using Grozi-32k and GP-180 data sets verify the effectiveness of the proposed model.
Keywords: Retail stores, Faster-RCNN, object localization, ResNet-18, triplet loss, data augmentation, product recognition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5871447 Designing of the Heating Process for Fiber- Reinforced Thermoplastics with Middle-Wave Infrared Radiators
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Manufacturing components of fiber-reinforced thermoplastics requires three steps: heating the matrix, forming and consolidation of the composite and terminal cooling the matrix. For the heating process a pre-determined temperature distribution through the layers and the thickness of the pre-consolidated sheets is recommended to enable forming mechanism. Thus, a design for the heating process for forming composites with thermoplastic matrices is necessary. To obtain a constant temperature through thickness and width of the sheet, the heating process was analyzed by the help of the finite element method. The simulation models were validated by experiments with resistance thermometers as well as with an infrared camera. Based on the finite element simulation, heating methods for infrared radiators have been developed. Using the numeric simulation many iteration loops are required to determine the process parameters. Hence, the initiation of a model for calculating relevant process parameters started applying regression functions.Keywords: Fiber-reinforced thermoplastics, heating strategies, middle-wave infrared radiator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17421446 Immunity of Integrated Drive System, Effects of Radiated and Conducted Emission
Authors: M. Ektesabi
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In this paper the problems associated with immunity of embedded systems used in Motor-Drive systems are investigated and appropriate solutions are presented. Integration of VSD motor systems (Integral Motor) while partially reducing some of these effects, adds to immunity problem of their embedded systems. Fail safe operation of an Integral Motor in arduous industrial environments is considered. In this paper an integral motor with a unique design is proposed to overcome critical issues such as heat, vibration and electromagnetic interference which are damaging to sensitive electronics without requirement of any additional cooling system. Advantages of the proposed Integral motor are compactness of combo motor and drive system with no external cabling/wiring. This motor provides a perfect shielding for least amount of radiated emission. It has an inbuilt filter for EMC compliance and has been designed to provide lower EMC noise for immunity of the internal electronics as well as the other neighbouring systems.Keywords: Electromagnetic Interference, Immunity, IntegralMotor, Radiated & Conducted Emission, Sensitive Electronics, Variable Speed Drive
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19031445 The Study of Magnetic and Transport Properties in Normal State Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ
Authors: Risdiana, D. Suhendar, S. Pratiwi, W. A. Somantri, T. Saragi
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The effect of partially substitution of magnetic impurity Fe for Cu to the magnetic and transport properties in electron-doped superconducting cuprates of Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ (ECCFO) with y = 0, 0.010, 0.020, and 0.050 has been studied, in order to investigate the mechanism of magnetic and transport properties of ECCFO in normal-state. Magnetic properties are investigated by DC magnetic-susceptibility measurements that carried out at low temperatures down to 2 K using a standard SQUID magnetometer in a magnetic field of 5 Oe on field cooling. Transport properties addressed to electron mobility, are extracted from radius of electron localization calculated from temperature dependence of resistivity. For y = 0, temperature dependence of dc magnetic-susceptibility (χ) indicated the change of magnetic behavior from paramagnetic to diamagnetic below 15 K. Above 15 K, all samples show paramagnetic behavior with the values of magnetic moment in every volume unit increased with increasing y. Electron mobility decreased with increasing y.Keywords: DC magnetic-susceptibility, electron mobility, Eu1.85+yCe0.15-yCu1-yFeyO4+α-δ, normal state.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 39501444 Electrophysical and Thermoelectric Properties of Nano-scaled In2O3:Sn, Zn, Ga-Based Thin Films: Achievements and Limitations for Thermoelectric Applications
Authors: G. Korotcenkov, V. Brinzari, B. K. Cho
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The thermoelectric properties of nano-scaled In2O3:Sn films deposited by spray pyrolysis are considered in the present report. It is shown that multicomponent In2O3:Sn-based films are promising material for the application in thermoelectric devices. It is established that the increase in the efficiency of thermoelectric conversion at CSn~5% occurred due to nano-scaled structure of the films studied and the effect of the grain boundary filtering of the low energy electrons. There are also analyzed the limitations that may appear during such material using in devices developed for the market of thermoelectric generators and refrigerators. Studies showed that the stability of nano-scaled film’s parameters is the main problem which can limit the application of these materials in high temperature thermoelectric converters.Keywords: Energy conversion technologies, thermoelectricity, In2O3-based films, power factor, nanocomposites, stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14211443 Characterization of ZrO2/PEG Composite Film as Immobilization Matrix for Glucose Oxidase
Authors: N. M. Ahmad, J. Abdullah, N. I. Ramli, S. Abd Rahman, N. E. Azmi, Z. Hamzah, A. Saat, N. H. Rahman
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A biosensor based on glucose oxidase (GOx) immobilized onto nanoparticles zirconium oxide with polyethylene nanocomposite for glucose monitoring has been designed. The CTAB/PEG/ZrO2/GOx nanocomposite was deposited onto screen printed carbon paste (SPCE) electrode via spin coating technique. The properties of CTAB/PEG/ZrO2/GOx were study using scanning electron microscopy (SEM). The SPE modified with the CTAB/PEG/ZrO2/GOx showed electrocatalytical response to the oxidation of glucose when ferrocene carboxaldehyde was used as an artificial redox mediator, which was studied by cyclic voltammetry (CV). Several parameters such as working potential, effect of pH and effect of ZrO2/PEG layers that governed the analytical performance of the biosensor, have been studied. The biosensor was applied to detect glucose with a linear range of 0.4 to 2.0 mmol L−1 with good repetability and reproducibility.Keywords: Nanocomposite, Nanoparticles, Modified SPE, Ferrocenecarboxaldehyde.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22671442 Vibration Analysis of the Gas Turbine Considering Dependency of Stiffness and Damping on Frequency
Authors: Hamed Jamshidi, Pooya Djamshidi
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In this paper the complete rotor system including elastic shaft with distributed mass, allowing for the effects of oil film in bearings. Also, flexibility of foundation is modeled. As a whole this article is a relatively complete research in modeling and vibration analysis of rotor considering gyroscopic effect, damping, dependency of stiffness and damping coefficients on frequency and solving the vibration equations including these parameters. On the basis of finite element method and utilizing four element types including element of shaft, disk, bearing and foundation and using MATLAB, a computer program is written. So the responses in several cases and considering different effects are obtained. Then the results are compared with each other, with exact solutions and results of other papers.Keywords: Damping coefficients , Finite element method, Modeling , Rotor vibration
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24921441 Experimental Investigation and Hardness Analysis of Chromoly Steel Multipass Welds Using GMAW
Authors: Ramesh S., Sasiraaju A. S., Sidhaarth K., Sudhan Rajkumar N., Manivel Muralidaran V.
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This work presents the result of investigations aimed at determining the hardness of the welded Chromoly (A 4130) steel plate of 2” thickness. Multi pass welding for the thick sections was carried out and analyzed for the Chromoly alloy steel plates. The study of hardness at the weld metal reveals that there is the presence of different micro structure products which yields diverse properties. The welding carried out using GMAW with ER70s-2 electrode. Single V groove design was selected for the butt joint configuration. The presence of hydrogen has been suppressed by selecting low hydrogen electrode. Preheating of the plate prior to welding reduces the cooling rate which also affects the weld metal microstructure. The shielding gas composition used in this analysis is 80% Ar-20% CO2. The experimental analysis gives the detailed study of the hardness of the material.
Keywords: Chromoly, Gas Metal Arc Weld (GMAW), Hardness, Multi pass weld, Shielding gas composition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30011440 Numerical Simulation of Investment Casting of Gold Jewelry: Experiments and Validations
Authors: Marco Actis Grande, Somlak Wannarumon
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This paper proposes the numerical simulation of the investment casting of gold jewelry. It aims to study the behavior of fluid flow during mould filling and solidification and to optimize the process parameters, which lead to predict and control casting defects such as gas porosity and shrinkage porosity. A finite difference method, computer simulation software FLOW-3D was used to simulate the jewelry casting process. The simplified model was designed for both numerical simulation and real casting production. A set of sensor acquisitions were allocated on the different positions of the wax tree of the model to detect filling times, while a set of thermocouples were allocated to detect the temperature during casting and cooling. Those detected data were applied to validate the results of the numerical simulation to the results of the real casting. The resulting comparisons signify that the numerical simulation can be used as an effective tool in investment-casting-process optimization and casting-defect prediction.Keywords: Computer fluid dynamic, Investment casting, Jewelry, Mould filling, Simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27381439 Degradability Studies of Photodegradable Plastic Film
Authors: Nurul, A.M.Y., Rahmah, M., Muhammad, A.
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Polypropylene blended with natural oil and pigment additives has been studied. Different formulations for each compound were made into polybag used for cultivation of oil palm seedlings for strength and mechanical properties studies. One group of sample was exposed under normal sunlight to initiate degradation and another group of sample was placed under shaded area for five months. All samples were tested for tensile strength to determine the degradation effects. The tensile strength of directly exposed sunlight samples and shaded area showed up to 50% and 25% degradation respectively. However, similar reduction of Young’s modulus for all samples was found for both exposures. Structural investigations were done using FTIR to detect deformation. The natural additives that were used in the studies were all natural and environmental friendly
Keywords: Agriculture, mechanical strength, photodegradable polymer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27541438 An Evaluation of the Oxide Layers in Machining Swarfs to Improve Recycling
Authors: J. Uka, B. McKay, T. Minton, O. Adole, R. Lewis, S. J. Glanvill, L. Anguilano
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Effective heat treatment conditions to obtain maximum aluminium swarf recycling are investigated in this work. Aluminium swarf briquettes underwent treatments at different temperatures and cooling times to investigate the improvements obtained in the recovery of aluminium metal. The main issue for the recovery of the metal from swarfs is to overcome the constraints due to the oxide layers present in high concentration in the swarfs since they have a high surface area. Briquettes supplied by Renishaw were heat treated at 650, 700, 750, 800 and 850 ℃ for 1-hour and then cooled at 2.3, 3.5 and 5 ℃/min. The resulting material was analysed using SEM EDX to observe the oxygen diffusion and aluminium coalescence at the boundary between adjacent swarfs. Preliminary results show that, swarf needs to be heat treated at a temperature of 850 ℃ and cooled down slowly at 2.3 ℃/min to have thin and discontinuous alumina layers between the adjacent swarf and consequently allowing aluminium coalescence. This has the potential to save energy and provide maximum financial profit in preparation of swarf briquettes for recycling.
Keywords: Aluminium, swarf, oxide layers, recycle, reuse.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5771437 Experimental Investigation and Optimization of Nanoparticle Mass Concentration and Heat Input of Loop Heat Pipe
Authors: P. Gunnasegaran, M. Z. Abdullah, M. Z. Yusoff, Nur Irmawati
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This study presents experimental and optimization of nanoparticle mass concentration and heat input based on the total thermal resistance (Rth) of loop heat pipe (LHP), employed for PCCPU cooling. In this study, silica nanoparticles (SiO2) in water with particle mass concentration ranged from 0% (pure water) to 1% is considered as the working fluid within the LHP. The experimental design and optimization is accomplished by the design of experimental tool, Response Surface Methodology (RSM). The results show that the nanoparticle mass concentration and the heat input have significant effect on the Rth of LHP. For a given heat input, the Rth is found to decrease with the increase of the nanoparticle mass concentration up to 0.5% and increased thereafter. It is also found that the Rth is decreased when the heat input is increased from 20W to 60W. The results are optimized with the objective of minimizing the Rth, using Design-Expert software, and the optimized nanoparticle mass concentration and heat input are 0.48% and 59.97W, respectively, the minimum thermal resistance being 2.66 (ºC/W).Keywords: Loop heat pipe, nanofluid, optimization, thermal resistance.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18241436 A Program Based on Artistic and Musical Activities to Acquire Educational Concepts for Children with Learning Difficulties
Authors: Ahmed Amin Mousa, Huda Mazeed, Eman Saad
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The study aims to identify the extent of effectiveness of the artistic formation program using some types of pastes to reduce the hyperactivity of the kindergarten children with learning difficulties. The researchers have discussed the aforesaid topic, where the research sample included 120 children of ages between 5 to 6 years, from five schools for special needs, learning disability section, Cairo Governorate. The study used the quasi-empirical method, which depends on designing one group using the pre& post application measurements for the group to validate both, hypothesis and effectiveness of the program. The variables of the study were specified as follows; artistic formation program using Paper Mache as an independent variable, and its effect on the skills of kindergarten child with learning disabilities, as a dependent variable. The researchers utilized the application of an artistic formation program consisting of artistic and musical skills for kindergarten children with learning disabilities. The tools of the study, designed by the researchers, included: observation card used for recording the culling paper using pulp molding skills for kindergarten children with learning difficulties during practicing the artistic formation activity. Additionally, there was a program utilizing Artistic and Musical Activities for kindergarten children with learning disabilities to acquire educational concepts. The study was composed of 20 lessons for fine art activities and 20 lessons for musical activities, with obligation of giving the musical lesson with art lesson in one session to cast on the kindergarten child some educational concepts.
Keywords: musical activities, developing skills, early childhood, educational concepts, learning difficulties
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5491435 A Digital Media e-Learning Training Strategy for Healthcare Employees: Cost effective Distance Learning by Collaborative offline / online Engagement and Assessment
Authors: Lynn. J. MacFarlane. A
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Within the healthcare system, training and continued professional development although essential, can be effected by cost and logistical restraints due to the nature of healthcare provision e.g employee shift patterns, access to expertise, cost factors in releasing staff to attend training etc. The use of multimedia technology for the development of e-learning applications is also a major cost consideration for healthcare management staff, and this type of media whether optical or on line requires careful planning in order to remain inclusive of all staff with potentially varied access to multimedia computing. This paper discusses a project in which the use of DVD authoring technology has been successfully implemented to meet the needs of distance learning and user considerations, and is based on film production techniques and reduced product turnaround deadlines.
Keywords: DVD, healthcare, distance learning, cost.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15311434 Influence of Thermal Annealing on The Structural Properties of Vanadyl Phthalocyanine Thin Films: A Comparative Study
Authors: Fakhra Aziz, K. Sulaiman, M. R. Muhammad, M. Hassan Sayyad, Kh. Karimov
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This paper presents a comparative study on Vanadyl Phthalocyanine (VOPc) thin films deposited by thermal evaporation and spin coating techniques. The samples were prepared on cleaned glass substrates and annealed at various temperatures ranging form 95oC to 155oC. To obtain the morphological and structural properties of VOPc thin films, X-ray diffraction (XRD) technique and atomic force microscopy (AFM) have been implied. The AFM topographic images show a very slight difference in the thermally grown films, before and after annealing, however best results are achieved for the spin-cast film annealed at 125oC. The XRD spectra show no existence of the sharp peaks, suggesting the material to be amorphous. The humps in the XRD patterns indicate the presence of some crystallites.Keywords: Annealing, optical properties, thin films, Vanadylphthalocyanine.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24381433 Thermal Characterization of Smart and Large-Scale Building Envelope System in a Subtropical Climate
Authors: Andrey A. Chernousov, Ben Y. B. Chan
Abstract:
The thermal behavior of a large-scale, phase change material (PCM) enhanced building envelope system was studied in regard to the need for pre-fabricated construction in subtropical regions. The proposed large-scale envelope consists of a reinforced aluminum skin, insulation core, phase change material and reinforced gypsum board. The PCM impact on an energy efficiency of an enveloped room was resolved by validation of the EnergyPlus numerical scheme and optimization of a smart material location in the core. The PCM location was optimized by a minimization method of a cooling energy demand. It has been shown that there is good agreement between the test and simulation results. The optimal location of the PCM layer in Hong Kong summer conditions has been then recomputed for core thicknesses of 40, 60 and 80 mm. A non-dimensional value of the optimal PCM location was obtained to be same for all the studied cases and the considered external and internal conditions.
Keywords: Thermal performance, phase change material, energy efficiency, PCM optimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2229