Search results for: Surface temperature
1653 Extension of a Smart Piezoelectric Ceramic Rod
Authors: Ali Reza Pouladkhan, Jalil Emadi, Hamed Habibolahiyan
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This paper presents an exact solution and a finite element method (FEM) for a Piezoceramic Rod under static load. The cylindrical rod is made from polarized ceramics (piezoceramics) with axial poling. The lateral surface of the rod is traction-free and is unelectroded. The two end faces are under a uniform normal traction. Electrically, the two end faces are electroded with a circuit between the electrodes, which can be switched on or off. Two cases of open and shorted electrodes (short circuit and open circuit) will be considered. Finally, a finite element model will be used to compare the results with an exact solution. The study uses ABAQUS (v.6.7) software to derive the finite element model of the ceramic rod.
Keywords: Finite element method, Ceramic rod; Axial poling, Normal traction, Short circuit, Open circuit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19481652 Effect of Temperature on the Performance of Multi-Stage Distillation
Authors: A. Diaf, H. Aburideh, Z.Tigrine, D. Tassalit, F.Alaoui
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The tray/multi-tray distillation process is a topic that has been investigated to great detail over the last decade by many teams such as Jubran et al. [1], Adhikari et al. [2], Mowla et al. [3], Shatat et al. [4] and Fath [5] to name a few. A significant amount of work and effort was spent focusing on modeling and/simulation of specific distillation hardware designs. In this work, we have focused our efforts on investigating and gathering experimental data on several engineering and design variables to quantify their influence on the yield of the multi-tray distillation process. Our goals are to generate experimental performance data to bridge some existing gaps in the design, engineering, optimization and theoretical modeling aspects of the multi-tray distillation process.Keywords: Distillation, Desalination, Multi-Stage still, Solar Energy
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18111651 The Design of PIP Controller for a Thermal System with Large Time Delay
Authors: Seiyed Hamid Zareh, Atabak Sarrafan, Kambiz Ghaemi Osgouie
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This paper will first describe predictor controllers when the proportional-integral-derivative (PID) controllers are inactive for procedures that have large delay time (LDT) in transfer stage. Therefore in those states, the predictor controllers are better than the PID controllers, then compares three types of predictor controllers. The value of these controller-s parameters are obtained by trial and error method, so here an effort has been made to obtain these parameters by Ziegler-Nichols method. Eventually in this paper Ziegler-Nichols method has been described and finally, a PIP controller has been designed for a thermal system, which circulates hot air to keep the temperature of a chamber constant.Keywords: Proportional-integral-predictive controller, Transferfunction, Delay time, Transport-lag.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17941650 Flood Scenarios for Hydrological and Hydrodynamic Modelling
Authors: Md. Sharif Imam Ibne Amir, Mohammad Masud Kamal khan, Mohammad Golam Rasul, Raj H Sharma, Fatema Akram
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Future flood can be predicted using the probable maximum flood (PMF). PMF is calculated using the historical discharge or rainfall data considering the other climatic parameters remaining stationary. However climate is changing globally and the key climatic variables are temperature, evaporation, rainfall and sea level rise are likely to change. To develop scenarios to a basin or catchment scale these important climatic variables should be considered. Nowadays scenario based on climatic variables is more suitable than PMF. Six scenarios were developed for a large Fitzroy basin and presented in this paper.
Keywords: Climate change, rainfall, potential evaporation, scenario, sea level rise (SLR), sub-catchment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 33771649 Electrolytic Dissolutions of UO2 and SIMFUEL in Carbonate Solutions at Several pHs
Authors: Kwang-Wook Kim, Geun-Il Park, Eil-Hee Lee, Kune-Woo Lee, Kee-Chan Song
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Electrolytic dissolution characteristics of UO2 and SIMFUEL electrodes were studied at several potentials in carbonate solutions of a high concentration at several pHs. The electrolytic uranium dissolution was much affected by a corrosion product of UO2CO3 generated at the electrode during the dissolution in carbonate solution. The corrosion product distorted the voltammogram at UO2 and SIMFUEL electrodes in the potential region of oxygen evolution and increased the overpotential of oxygen evolution at the electrode. The effective dissolution in a carbonate solution could be obtained at an applied potential such as +4 V (vs SSE) or more which had an overpotential of oxygen evolution high enough to rupture the corrosion product on the electrode surface.Keywords: Anodic, Electrolytic, Dissolution, SIMFUEL, Uranium dioxide, Carbonate
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15261648 Detection, Tracking and Classification of Vehicles and Aircraft based on Magnetic Sensing Technology
Authors: K. Dimitropoulos, N. Grammalidis, I. Gragopoulos, H. Gao, Th. Heuer, M. Weinmann, S. Voit, C. Stockhammer, U. Hartmann, N. Pavlidou
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Existing ground movement surveillance technologies at airports are subjected to limitations due to shadowing effects or multiple reflections. Therefore, there is a strong demand for a new sensing technology, which will be cost effective and will provide detection of non-cooperative targets under any weather conditions. This paper aims to present a new intelligent system, developed within the framework of the EC-funded ISMAEL project, which is based on a new magnetic sensing technology and provides detection, tracking and automatic classification of targets moving on the airport surface. The system is currently being installed at two European airports. Initial experimental results under real airport traffic demonstrate the great potential of the proposed system.Keywords: Air traffic management, magnetic sensors, multitracking, A-SMGCS.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19331647 Optimization of Artificial Ageing Time and Temperature on Evaluation of Hardness and Resistivity of Al-Si-Mg (Cu or/& Ni) Alloys
Authors: A. Hossain, A. S. W. Kurny
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The factors necessary to obtain an optimal heat treatment that influence the hardness and resistivity of Al-6Si-0.5Mg casting alloys with Cu or/and Ni additions were investigated. The alloys were homogenised (24hr at 500oC), solutionized (2hr at 540oC) and artificially ageing at various times and temperatures. The alloys were aged isochronally for 60 minutes at temperatures up to 400oC and isothermally at 150, 175, 200, 225, 250 & 300oC for different periods in the range 15 to 360 minutes. The hardness and electrical resistivity of the alloys were measured for various artificial ageing times and temperatures. From the isochronal ageing treatment, hardness found maximum ageing at 225oC. And from the isothermal ageing treatment, hardness found maximum for 60 minutes at 225oC. So the optimal heat treatment consists of 60 minutes ageing at 225oC.
Keywords: Ageing, Al-Si-Mg alloy, hardness, resistivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30661646 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 13941645 Comparing the Durability of Saudi Silica Sands for Use in Foundry Processing
Authors: Mahdi Alsagour, Sam Ramrattan
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This paper was developed to investigate two types of sands from the Kingdom of Saudi Arabia (KSA) for potential use in the global metal casting industry. Four types of sands were selected for study, two of the sand systems investigated are natural sands from the KSA. The third sand sample is a heat processed synthetic sand and the last sample is commercially available US silica sand that is used as a control in the study. The purpose of this study is to define the durability of the four sand systems selected for foundry usage. Additionally, chemical analysis of the sand systems is presented before and after elevated temperature exposure. Results show that Saudi silica sands are durable and can be used in foundry processing.
Keywords: Alternative molding media, foundry sand, reclamation, silica sand, specialty sand.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7331644 Finite Element Analysis of Crack Welding Process
Authors: Thomas Jin-Chee Liu
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The numerical simulation of the crack welding process is reported in this paper. The thermo-electro-structural coupled-field finite element analysis is adopted to investigate the welding process of crack surfaces. In the simulation, the pressure-dependent and temperature-dependent electrical contact conditions are considered. From the results, the crack surfaces can melt and weld together under the compressive load and electric current. The contact pressure effect must be considered in the finite element analysis to obtain more practical results.
Keywords: Crack welding, contact pressure, Joule heating, finite element, coupled-field.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23621643 Optimization of Real Time Measured Data Transmission, Given the Amount of Data Transmitted
Authors: Michal Kopcek, Tomas Skulavik, Michal Kebisek, Gabriela Krizanova
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The operation of nuclear power plants involves continuous monitoring of the environment in their area. This monitoring is performed using a complex data acquisition system, which collects status information about the system itself and values of many important physical variables e.g. temperature, humidity, dose rate etc. This paper describes a proposal and optimization of communication that takes place in teledosimetric system between the central control server responsible for the data processing and storing and the decentralized measuring stations, which are measuring the physical variables. Analyzes of ongoing communication were performed and consequently the optimization of the system architecture and communication was done.
Keywords: Communication protocol, transmission optimization, data acquisition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18211642 Manufacturing Process and Cost Estimation through Process Detection by Applying Image Processing Technique
Authors: Chalakorn Chitsaart, Suchada Rianmora, Noppawat Vongpiyasatit
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In order to reduce the transportation time and cost for direct interface between customer and manufacturer, the image processing technique has been introduced in this research where designing part and defining manufacturing process can be performed quickly. A3D virtual model is directly generated from a series of multi-view images of an object, and it can be modified, analyzed, and improved the structure, or function for the further implementations, such as computer-aided manufacturing (CAM). To estimate and quote the production cost, the user-friendly platform has been developed in this research where the appropriate manufacturing parameters and process detections have been identified and planned by CAM simulation.
Keywords: Image processing technique, Feature detections, Surface registrations, Capturing multi-view images, Production costs, and Manufacturing processes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19761641 Experimental Investigation of Hydrogen Addition in the Intake Air of Compressed Engines Running on Biodiesel Blend
Authors: Hendrick Maxil Zárate Rocha, Ricardo da Silva Pereira, Manoel Fernandes Martins Nogueira, Carlos R. Pereira Belchior, Maria Emilia de Lima Tostes
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This study investigates experimentally the effects of hydrogen addition in the intake manifold of a diesel generator operating with a 7% biodiesel-diesel oil blend (B7). An experimental apparatus setup was used to conduct performance and emissions tests in a single cylinder, air cooled diesel engine. This setup consisted of a generator set connected to a wirewound resistor load bank that was used to vary engine load. In addition, a flowmeter was used to determine hydrogen volumetric flowrate and a digital anemometer coupled with an air box to measure air flowrate. Furthermore, a digital precision electronic scale was used to measure engine fuel consumption and a gas analyzer was used to determine exhaust gas composition and exhaust gas temperature. A thermopar was installed near the exhaust collection to measure cylinder temperature. In-cylinder pressure was measured using an AVL Indumicro data acquisition system with a piezoelectric pressure sensor. An AVL optical encoder was installed in the crankshaft and synchronized with in-cylinder pressure in real time. The experimental procedure consisted of injecting hydrogen into the engine intake manifold at different mass concentrations of 2,6,8 and 10% of total fuel mass (B7 + hydrogen), which represented energy fractions of 5,15, 20 and 24% of total fuel energy respectively. Due to hydrogen addition, the total amount of fuel energy introduced increased and the generators fuel injection governor prevented any increases of engine speed. Several conclusions can be stated from the test results. A reduction in specific fuel consumption as a function of hydrogen concentration increase was noted. Likewise, carbon dioxide emissions (CO2), carbon monoxide (CO) and unburned hydrocarbons (HC) decreased as hydrogen concentration increased. On the other hand, nitrogen oxides emissions (NOx) increased due to average temperatures inside the cylinder being higher. There was also an increase in peak cylinder pressure and heat release rate inside the cylinder, since the fuel ignition delay was smaller due to hydrogen content increase. All this indicates that hydrogen promotes faster combustion and higher heat release rates and can be an important additive to all kind of fuels used in diesel generators.Keywords: Diesel engine, hydrogen, dual fuel, combustion analysis, performance, emissions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13151640 Photocatalytic Degradation of Produced Water Hydrocarbon of an Oil Field by Using Ag-Doped TiO2 Nanoparticles
Authors: Hamed Bazrafshan, Saeideh Dabirnia, Zahra Alipour Tesieh, Samaneh Alavi, Bahram Dabir
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In this study, the removal of pollutants of a real produced water sample from an oil reservoir (a light oil reservoir), using a photocatalytic degradation process in a cylindrical glass reactor, was investigated. Using TiO2 and Ag-TiO2 in slurry form, the photocatalytic degradation was studied by measuring the Chemical Oxygen Demand (COD) parameter, qualitative analysis, and GC-MS. At first, optimization of the parameters on photocatalytic degradation of hydrocarbon pollutants in real produced water, using TiO2 nanoparticles as photocatalysts under UV light, was carried out applying response surface methodology. The results of the design of the experiment showed that the optimum conditions were at a catalyst concentration of 1.14 g/lit and pH of 2.67, and the percentage of COD removal was 72.65%.
Keywords: Photocatalyst, Ag-doped, TiO2, produced water, nanoparticles.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5171639 Study of Methylene Blue Dye Adsorption on to Activated Carbons from Olive Stones
Authors: L. Temdrara, A. Khelifi, A. Addoun
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Activated carbons were produced from olive stones by a chemical process. The activated carbon (AC) were modified by nitric acid and used as adsorbents for the removal of methylene blue dye from aqueous solution. The activated carbons were characterized by nitrogen adsorption and enthalpy of immersion. Batch adsorption experiments were carried out to study the effect of initial different concentrations solution on dye adsorption properties. Isotherms were fitted to Langmuir model, and corresponding parameters were determined. The results showed that the increase of ration of ZnCl2 leads to increase in apparent surface areas and produces activated carbons with pore structure more developed. However, the maximum MB uptakes for all carbons were determined and correlated with activated carbons characteristics.
Keywords: Adsorption, activated carbon, chemical activation, enthalpy of immersion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22811638 A Comparison of Conventional and Biodegradable Chelating Agent in Different Type of Surfactant Solutions for Soap Scum Removal
Authors: Prariyada Theptat, Sumaeth Chavadej, John F. Scamehorn
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One of the most challenges for hard surface cleaning product is to get rid of soap scum, a filmy sticky layer in the bathroom. The deposits of soap scum can be removed by using a proper surfactant solution with chelating agent. Unfortunately, the conventional chelating agent, ethylenediamine tetraacetic acid (EDTA), has low biodegradability, which can be tolerance in water resources and harmful to aquatic animal and microorganism. In this study, two biodegradable chelating agents, ethylenediamine disuccinic acid (EDDS) and glutamic acid diacetic acid (GLDA) were introduced as a replacement of EDTA. The result shows that using GLDA with amphoteric surfactant gave the highest equilibrium solubility of soap scum.
Keywords: Biodegradable chelating agent, EDDS, GLDA, Soap scum.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 50431637 Three-Dimensional Generalized Thermoelasticity with Variable Thermal Conductivity
Authors: Hamdy M. Youssef, Mowffaq Oreijah, Hunaydi S. Alsharif
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In this paper, a three-dimensional model of the generalized thermoelasticity with one relaxation time and variable thermal conductivity has been constructed. The resulting non-dimensional governing equations together with the Laplace and double Fourier transforms techniques have been applied to a three-dimensional half-space subjected to thermal loading with rectangular pulse and traction free in the directions of the principle co-ordinates. The inverses of double Fourier transforms, and Laplace transforms have been obtained numerically. Numerical results for the temperature increment, the invariant stress, the invariant strain, and the displacement are represented graphically. The variability of the thermal conductivity has significant effects on the thermal and the mechanical waves.
Keywords: Thermoelasticity, three-dimensional, Laplace transforms, Fourier transforms, thermal conductivity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7491636 Mixed Convective Heat Transfer in Water-Based Al2O3 Nanofluid in Horizontal Rectangular Duct
Authors: Nur Irmawati, H.A. Mohammed
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In the present study, mixed convection in a horizontal rectangular duct using Al2O3 is numerically investigated. The effects of different Rayleigh number, Reynolds number and radiation on flow and heat transfer characteristics are studied in detail. This study covers Rayleigh number in the range of 2 × 10^6 ≤ Ra ≤ 2 × 10^7 and Reynolds number in the range of 100 ≤ Re ≤ 1100. Results reveal that the Nusselt number increases as Reynolds and Rayleigh numbers increase. It is also found that the dimensionless temperature distribution increases as Rayleigh number increases.
Keywords: Numerical simulation, Mixed convection, Horizontal rectangular duct, Nanofluids.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23591635 Kinetics Study of Ammonia Removal from Synthetic Waste Water
Authors: Edison Muzenda, John Kabuba, Freeman Ntuli, Mansoor Mollagee
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The aim of this study was to investigate ammonium exchange capacity of natural and activated clinoptilolite from Kwazulu-Natal Province, South Africa. X – ray fluorescence (XRF) analysis showed that the clinoptilolite contained exchangeable ions of sodium, potassium, calcium and magnesium. This analysis also confirmed that the zeolite sample had a high silicon composition compared to aluminium. Batch equilibrium studies were performed in an orbital shaker and the data fitted the Langmuir isotherm very well. The ammonium exchange capacity was found to increase with pH and temperature. Clinoptilolite functionalization with hydrochloric acid increased its ammonia uptake ability.Keywords: Activated clinoptilolite, Ammonium exchange, Equilibrium, Functionalization, Langmuir isotherm
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22521634 The Catalytic Effects of Potassium Dichromate on the Pyrolysis of Polymeric Mixtures Part I: Hazelnut Shell and Polyethylene Oxide and their Blend Cases
Authors: A. Caglar, B. Aydinli
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The pyrolysis of hazelnut shell, polyethylene oxide and their blends were carried out catalytically at 500 and 650 ºC. Potassium dichromate was chosen according to its oxidative characteristics and decomposition temperature (500 ºC) where decomposition products are CrO3 and K2CrO4. As a main effect, a remarkable increase in gasification was observed using this catalyst for pure components and blends especially at 500 ºC rather than 650 ºC contrary to the main observation in the pyrolysis process. The increase in gas product quantity was compensated mainly with decrease in solid product and additionally in some cases liquid products.
Keywords: Hazelnut shell, Polyethylene oxide, Potassium dichromate, Pyrolysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18371633 Characterization of Catalagzi Fly Ash for Heavy Metal Adsorption
Authors: Nurcan Tugrul, Nil Baran Acarali, Seyma Kolemen, Emek Moroydor Derun, Sabriye Piskin
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Fly ash is a significant waste that is released of thermal power plants and defined as very fine particles that are drifted upward with up taken by the flue gases due to the burning of used coal [1]. The fly-ash is capable of removing organic contaminants in consequence of high carbon content, a large surface area per unit volume and contained heavy metals. Therefore, fly ash is used as an effective coagulant and adsorbent by pelletization [2, 3]. In this study, the possibility of use of fly ash taken from Turkey like low-cost adsorbent for adsorption of zinc ions found in waste water was investigated. The fly ash taken from Turkey was pelletized with bentonite and molass to evaluate the adsorption capaticity. For this purpose; analyses such as sieve analysis, XRD, XRF, FTIR and SEM were performed. As a result, it was seen that pellets prepared from fly ash, bentonite and molass would be used for zinc adsorption.Keywords: Fly ash, heavy metal, sieve, adsorbent.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25931632 Investigation of Ceramic-Metal Composites Produced by Electroless Ni Plating of AlN- Astaloy Cr-M
Authors: A. Yönetken, A. Erol, A. Yakar, G. Peşmen
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The microstructure, mechanical properties and metalgraphic characteristics of Ni plated AlN-Astaloy Cr-M powders were investigated using specimens produced by tube furnace sintering at 1000-1400 °C temperature. A uniform nickel layer on AlN powders was deposited prior to sintering using electroless plating technique. A composite consisting of ternary additions, metallic phase, Ni and ceramic phase AlN within a matrix of Astaloy Cr-M had been prepared under Ar shroud and then tube furnace sintered. The experimental results carried out by using XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) for composition (10% AlN-Astaloy Cr-M) 10% Ni at 1400 °C suggest that the best properties as 132.45HB and permittivity were obtained at 1400 °C.
Keywords: Composite, Electroless, Nickel plating, Powder metallurgy, Sintering.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15951631 A Numerical Simulation of Arterial Mass Transport in Presence of Magnetic Field-Links to Atherosclerosis
Authors: H. Aminfar, M. Mohammadpourfard, K. Khajeh
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This paper has focused on the most important parameters in the LSC uptake; inlet Re number and Sc number in the presence of non-uniform magnetic field. The magnetic field is arising from the thin wire with electric current placed vertically to the arterial blood vessel. According to the results of this study, applying magnetic field can be a treatment for atherosclerosis by reducing LSC along the vessel wall. Homogeneous porous layer as a arterial wall has been regarded. Blood flow has been considered laminar and incompressible containing Ferro fluid (blood and 4 % vol. Fe3O4) under steady state conditions. Numerical solution of governing equations was obtained by using the single-phase model and control volume technique for flow field.
Keywords: LDL Surface Concentration (LSC), Magnetic field, Computational fluid dynamics, Porous wall.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15741630 Gate Voltage Controlled Humidity Sensing Using MOSFET of VO2 Particles
Authors: A. A. Akande, B. P. Dhonge, B. W. Mwakikunga, A. G. J. Machatine
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This article presents gate-voltage controlled humidity sensing performance of vanadium dioxide nanoparticles prepared from NH4VO3 precursor using microwave irradiation technique. The X-ray diffraction, transmission electron diffraction, and Raman analyses reveal the formation of VO2 (B) with V2O5 and an amorphous phase. The BET surface area is found to be 67.67 m2/g. The humidity sensing measurements using the patented lateral-gate MOSFET configuration was carried out. The results show the optimum response at 5 V up to 8 V of gate voltages for 10 to 80% of relative humidity. The dose-response equation reveals the enhanced resilience of the gated VO2 sensor which may saturate above 272% humidity. The response and recovery times are remarkably much faster (about 60 s) than in non-gated VO2 sensors which normally show response and recovery times of the order of 5 minutes (300 s).
Keywords: VO2, VO2 (B), V2O5, MOSFET, gate voltage, humidity sensor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11391629 Using Lagrange Equations to Study the Relative Motion of a Mechanism
Authors: R. A. Petre, S. E. Nichifor, A. Craifaleanu, I. Stroe
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The relative motion of a robotic arm formed by homogeneous bars of different lengths and masses, hinged to each other is investigated. The first bar of the mechanism is articulated on a platform, considered initially fixed on the surface of the Earth, while for the second case the platform is considered to be in rotation with respect to the Earth. For both analyzed cases the motion equations are determined using the Lagrangian formalism, applied in its traditional form, valid with respect to an inertial reference system, conventionally considered as fixed. However, in the second case, a generalized form of the formalism valid with respect to a non-inertial reference frame will also be applied. The numerical calculations were performed using a MATLAB program.
Keywords: Lagrange equations, relative motion, inertial or non-inertial reference frame.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5801628 Influence of Some Technological Parameters on the Content of Voids in Composite during On-Line Consolidation with Filament Winding Technology
Authors: M. Stefanovska, B. Samakoski, S. Risteska, G. Maneski
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In this study was performed in situ consolidation of polypropylene matrix/glass reinforced roving by combining heating systems and roll pressing. The commingled roving during hoop winding was winded on a cylindrical mandrel. The work also presents the advances made in the processing of these materials into composites by conventional technique filament winding. Experimental studies were performed with changing parameters – temperature, pressure and speed. Finally, it describes the investigation of the optimal processing conditions that maximize the mechanical properties of the composites. These properties are good enough for composites to be used as engineering materials in many structural applications.
Keywords: Commingled fiber, consolidation heat, filament winding, voids.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23711627 Diagnostics of Fatigue Damage of Gas Turbine Engine Blades by Acoustic Emission Method
Authors: A.Urbach, M. Banov, V. Turko, Y.Feshchuk
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the work contains the results of complex investigation related to the evaluation of condition of working blades of gas turbine engines during fatigue tests by applying the acoustic emission method. It demonstrates the possibility of estimating the fatigue damage of blades in the process of factory tests. The acoustic emission criteria for detecting and testing the kinetics of fatigue crack distribution were detected. It also shows the high effectiveness of the method for non-destructive testing of condition of solid and cooled working blades for high-temperature gas turbine engines.Keywords: acoustic emission, blades for gas turbine engines, fatigue damage, diagnostics
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23581626 Study on Liquid Nitrogen Gravity Circulation Loop for Cryopumps in Large Space Simulator
Authors: Weiwei Shan, Wenjing Ding, Juan Ning, Chao He, Zijuan Wang
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Gravity circulation loop for the cryopumps of the space simulator is introduced, and two phase mathematic model of flow heat transfer is analyzed as well. Based on this model, the liquid nitrogen (LN2) gravity circulation loop including its equipment and layout is designed and has served as LN2 feeding system for cryopumps in one large space simulator. With the help of control software and human machine interface, this system can be operated flexibly, simply, and automatically under four conditions. When running this system, the results show that the cryopumps can be cooled down and maintained under the required temperature, 120 K.
Keywords: Cryopumps, gravity circulation loop, liquid nitrogen, two-phase.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8401625 Risk Assessment of Acrylamide Intake from Roasted Potatoes in Latvia
Authors: Irisa Murniece, Daina Karklina, Ruta Galoburda
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From food consumption surveys has been found that potato consumption comparing to other European countries is one of the highest. Hence acrylamide (AA) intake coming from fried potatoes in population might be high as well. The aim of the research was to determine acrylamide content and estimate intake of acrylamide from roasted potatoes bred and cultivated in Latvia. Five common Latvian potato varieties were selected: Lenora, Brasla, Imanta, Zile, and Madara. A two-year research was conducted during two periods: just after harvesting and after six months of storage. Time and temperature (210 ± 5°C) was recorded during frying. AA was extracted from potatoes by solid phase extraction and AA content was determined by LC-MS/MS. estimated intake of acrylamide ranges from 0.012 to 0.496μgkg-1 BW per day.
Keywords: potato, roasting, variety, acrylamide, Latvia, risk assessment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20621624 Catalytic Activity of Aluminum Impregnated Catalysts for the Degradation of Waste Polystyrene
Authors: J. Shah, M. Rasul Jan, Adnan
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The aluminum impregnated catalysts of Al-alumina (Al-Al2O3), Al-montmorillonite (Al-Mmn) and Al-activated charcoal (Al-AC) of various percent loadings were prepared by wet impregnation method and characterized by SEM, XRD and N2 adsorption/desorption (BET). The catalytic properties were investigated in the degradation of waste polystyrene (WPS). The results of catalytic degradation of Al metal, 20% Al-Al2O3, 5% Al-Mmn and 20% Al-AC were compared with each other for optimum conditions. Among the catalyst used 20% Al-Al2O3 was found the most effective catalyst. The BET surface area of 20% Al-Al2O3 determined was 70.2 m2/g. The SEM data revealed the catalyst with porous structure throughout the frame work with small nanosized crystallites. The yield of liquid products with 20% Al-Al2O3 (91.53 ± 2.27 wt%) was the same as compared to Al metal (91.20 ± 0.35 wt%) but the selectivity of hydrocarbons and yield of styrene monomer (56.32 wt%) was higher with 20% Al-Al2O3 catalyst.
Keywords: Impregnation, catalytic degradation, waste polystyrene, styrene.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2036