Search results for: Surface%20roughness%20%28SR%29
1116 Risk of Occupational Exposure to Cytotoxic Drugs: The Role of Handling Procedures of Hospital Workers
Authors: J. Silva, P. Arezes, R. Schierl, N. Costa
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In order to study environmental contamination by cytostatic drugs in Portugal hospitals, sampling campaigns were conducted in three hospitals in 2015 (112 samples). Platinum containing drugs and fluorouracil were chosen because both were administered in high amounts. The detection limit was 0.01 pg/cm² for platinum and 0.1 pg/cm² for fluorouracil. The results show that spills occur mainly on the patient`s chair, while the most referenced occurrence is due to an inadequately closed wrapper. Day hospitals facilities were detected as having the largest number of contaminated samples and with higher levels of contamination.
Keywords: Antineoplastic, drugs, exposure, surface.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10361115 The Study of Super Hydrophobic Surfaces Using High Speed Shadowgraphy
Authors: D. Jasikova, M. Kotek, V. Kopecky
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The aim of this article is the measurement of the basic characteristic of superhydrophobic surfaces using high speed shadowgraphy. Here we describe the novel patented system for the industrial production of superhydrophobic surfaces. These surfaces were investigated with two optically based measurement methods: impinging drop and inclined wall. The results of the visualization and analysis help to state the suitable sample with superhydrophobic properties for mathematic simulation.
Keywords: Antipearl effect, contact angle, hydrophobic, impinging drop, inclined wall, measurement, plasma, shadowgraphy, superhydrophobic surface.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24391114 Determination of Optical Constants of Semiconductor Thin Films by Ellipsometry
Authors: Aïssa Manallah, Mohamed Bouafia
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Ellipsometry is an optical method based on the study of the behavior of polarized light. The light reflected on a surface induces a change in the polarization state which depends on the characteristics of the material (complex refractive index and thickness of the different layers constituting the device). The purpose of this work is to determine the optical properties of semiconductor thin films by ellipsometry. This paper describes the experimental aspects concerning the semiconductor samples, the SE400 ellipsometer principle, and the results obtained by direct measurements of ellipsometric parameters and modelling using appropriate software.Keywords: Ellipsometry, optical constants, semiconductors, thin films.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13261113 Processing Design of Miniature Casting Incorporating Stereolithography Technologies
Authors: Pei-Hsing Huang, Wei-Ju Huang
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Investment casting is commonly used in the production of metallic components with complex shapes, due to its high dimensional precision, good surface finish, and low cost. However, the process is cumbersome, and the period between trial casting and final production can be very long, thereby limiting business opportunities and competitiveness. In this study, we replaced conventional wax injection with stereolithography (SLA) 3D printing to speed up the trial process and reduce costs. We also used silicone molds to further reduce costs to avoid the high costs imposed by photosensitive resin.
Keywords: Investment casting, stereolithography, wax molding, 3D printing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14721112 Steady State Rolling and Dynamic Response of a Tire at Low Frequency
Authors: Md Monir Hossain, Anne Staples, Kuya Takami, Tomonari Furukawa
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Tire noise has a significant impact on ride quality and vehicle interior comfort, even at low frequency. Reduction of tire noise is especially important due to strict state and federal environmental regulations. The primary sources of tire noise are the low frequency structure-borne noise and the noise that originates from the release of trapped air between the tire tread and road surface during each revolution of the tire. The frequency response of the tire changes at low and high frequency. At low frequency, the tension and bending moment become dominant, while the internal structure and local deformation become dominant at higher frequencies. Here, we analyze tire response in terms of deformation and rolling velocity at low revolution frequency. An Abaqus FEA finite element model is used to calculate the static and dynamic response of a rolling tire under different rolling conditions. The natural frequencies and mode shapes of a deformed tire are calculated with the FEA package where the subspace-based steady state dynamic analysis calculates dynamic response of tire subjected to harmonic excitation. The analysis was conducted on the dynamic response at the road (contact point of tire and road surface) and side nodes of a static and rolling tire when the tire was excited with 200 N vertical load for a frequency ranging from 20 to 200 Hz. The results show that frequency has little effect on tire deformation up to 80 Hz. But between 80 and 200 Hz, the radial and lateral components of displacement of the road and side nodes exhibited significant oscillation. For the static analysis, the fluctuation was sharp and frequent and decreased with frequency. In contrast, the fluctuation was periodic in nature for the dynamic response of the rolling tire. In addition to the dynamic analysis, a steady state rolling analysis was also performed on the tire traveling at ground velocity with a constant angular motion. The purpose of the computation was to demonstrate the effect of rotating motion on deformation and rolling velocity with respect to a fixed Newtonian reference point. The analysis showed a significant variation in deformation and rolling velocity due to centrifugal and Coriolis acceleration with respect to a fixed Newtonian point on ground.Keywords: Natural frequency, rotational motion, steady state rolling, subspace-based steady state dynamic analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13061111 Investigation of Undular Hydraulic Jump over Smooth Beds
Authors: F. Rostami, M. Shahrokhi, M. A. Md Said, S.R. Sabbagh-Yazdi
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Undular hydraulic jumps are illustrated by a smooth rise of the free surface followed by a train of stationary waves. They are sometimes experienced in natural waterways and rivers. The characteristics of undular hydraulic jumps are studied here. The height, amplitude and the main characteristics of undular jump is depended on the upstream Froude number and aspect ratio. The experiments were done on the smooth bed flume. These results compared with other researches and the main characteristics of the undular hydraulic jump were studied in this article.Keywords: Undular Hydraulic Jump, low Froude Number, wave characteristics
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19571110 Properties of Adipose Tissue Derived Mesenchymal Stem Cells with Long-Term Cryopreservation
Authors: Jienny Lee, In-Soo Cho, Sang-Ho Cha
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Adult mesenchymal stem cells (MSCs) have been investigated using preclinical approaches for tissue regeneration. Porcine MSCs (pMSCs) are capable of growing and attaching to plastic with a fibroblast-like morphology and then differentiating into bone, adipose, and cartilage tissues in vitro. This study was conducted to investigate the proliferating abilities, differentiation potentials, and multipotency of miniature pig adipose tissue-derived MSCs (mpAD-MSCs) with or without long-term cryopreservation, considering that cryostorage has the potential for use in clinical applications. After confirming the characteristics of the mpAD-MSCs, we examined the effect of long-term cryopreservation (> 2 years) on expression of cell surface markers (CD34, CD90 and CD105), proliferating abilities (cumulative population doubling level, doubling time, colony-forming unit, and MTT assay) and differentiation potentials into mesodermal cell lineages. As a result, the expression of cell surface markers is similar between thawed and fresh mpAD-MSCs. However, long-term cryopreservation significantly lowered the differentiation potentials (adipogenic, chondrogenic, and osteogenic) of mpAD-MSCs. When compared with fresh mpAD-MSCs, thawed mpAD-MSCs exhibited lower expression of mesodermal cell lineage-related genes such as peroxisome proliferator-activated receptor-g2, lipoprotein lipase, collagen Type II alpha 1, osteonectin, and osteocalcin. Interestingly, long-term cryostoraged mpAD-MSCs exhibited significantly higher cell viability than the fresh mpAD-MSCs. Long-term cryopreservation induced a 30% increase in the cell viability of mpAD-MSCs when compared with the fresh mpAD-MSCs at 5 days after thawing. However, long-term cryopreservation significantly lowered expression of stemness markers such as Oct3/4, Sox2, and Nanog. Furthermore, long-term cryopreservation negatively affected expression of senescence-associated genes such as telomerase reverse transcriptase and heat shock protein 90 of mpAD-MSCs when compared with the fresh mpAD-MSCs. The results from this study might be important for the successful application of MSCs in clinical trials after long-term cryopreservation.Keywords: Mesenchymal stem cells, Cryopreservation, Stemness, Senescence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20851109 Flow and Heat Transfer of a Nanofluid over a Shrinking Sheet
Authors: N. Bachok, N. L. Aleng, N. M. Arifin, A. Ishak, N. Senu
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The problem of laminar fluid flow which results from the shrinking of a permeable surface in a nanofluid has been investigated numerically. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. A similarity solution is presented which depends on the mass suction parameter S, Prandtl number Pr, Lewis number Le, Brownian motion number Nb and thermophoresis number Nt. It was found that the reduced Nusselt number is decreasing function of each dimensionless number.
Keywords: Boundary layer, Nanofluid, Shrinking sheet, Brownian motion, Thermophoresis, Similarity solution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27871108 Experimental Study of Adsorption Properties of Acid and Thermal Treated Bentonite from Tehran (Iran)
Authors: H. R. Moghadamzadeh, M. Naimi, H. Rahimzadeh, M. Ardjmand, V. M. Nansa, A. M. Ghanadi
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The Iranian bentonite was first characterized by Scanning Electron Microscopy (SEM), Inductively Coupled Plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF), X-ray Diffraction (XRD) and BET. The bentonite was then treated thermally between 150°C-250°C at 15min, 45min and 90min and also was activated chemically with different concentration of sulphuric acid (3N, 5N and 10N). Although the results of thermal activated-bentonite didn-t show any considerable changes in specific surface area and Cation Exchange Capacity (CEC), but the results of chemical treated bentonite demonstrated that such properties have been improved by acid activation process.Keywords: Acid activation, Bentonite, CEC, Thermal activation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28311107 Sliding Mode Control with Fuzzy Boundary Layer to Air-Air Interception Problem
Authors: Mustafa Resa Becan
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The performance of a type of fuzzy sliding mode control is researched by considering the nonlinear characteristic of a missile-target interception problem to obtain a robust interception process. The variable boundary layer by using fuzzy logic is proposed to reduce the chattering around the switching surface then is applied to the interception model which was derived. The performances of the sliding mode control with constant and fuzzy boundary layer are compared at the end of the study and the results are evaluated.
Keywords: Sliding mode control, fuzzy, boundary layer, interception problem.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19951106 Sliding Mode Control of a Bus Suspension System
Authors: Mujde Turkkan, Nurkan Yagiz
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The vibrations, caused by the irregularities of the road surface, are to be suppressed via suspension systems. In this paper, sliding mode control for a half bus model with air suspension system is presented. The bus is modelled as five degrees of freedom (DoF) system. The mathematical model of the half bus is developed using Lagrange Equations. For time domain analysis, the bus model is assumed to travel at certain speed over the bump road. The numerical results of the analysis indicate that the sliding mode controllers can be effectively used to suppress the vibrations and to improve the ride comfort of the busses.
Keywords: Sliding mode control, bus model, air suspension.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17561105 Adaptive Sliding Mode Observer for a Class of Systems
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In this paper, the performance of two adaptive observers applied to interconnected systems is studied. The nonlinearity of systems can be written in a fractional form. The first adaptive observer is an adaptive sliding mode observer for a Lipchitz nonlinear system and the second one is an adaptive sliding mode observer having a filtered error as a sliding surface. After comparing their performances throughout the inverted pendulum mounted on a car system, it was shown that the second one is more robust to estimate the state.Keywords: Adaptive observer, Lipchitz system, Interconnected fractional nonlinear system, sliding mode.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16481104 The Catalytic Activity of Cu2O Microparticles
Authors: Kanda Wongwailikhit
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Copper (I) oxide microparticles with the morphology of cubic and hollow sphere were synthesized with the assistance of surfactant as the shape controller. Both particles were then subjected to study the catalytic activity and observed the results of shape effects of catalysts on rate of catalytic reaction. The decolorizing reaction of crystal violet and sodium hydroxide was chosen and measured the decreasing of reactant with respect to times using spectrophotometer. The result revealed that morphology of crystal had no effect on the catalytic activity for crystal violet reaction but contributed to total surface area predominantly.Keywords: Copper (I) oxide, Catalytic activity, Crystal violet.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20421103 Approximate Method of Calculation of Inviscid Hypersonic Flow
Authors: F. Sokhanvar, A. B. Khoshnevis
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In the present work steady inviscid hypersonic flows are calculated by approximate Method. Maslens' inverse method is the chosen approximate method. For the inverse problem, parabolic shock shape is chosen for the two-dimensional flow, and the body shape and flow field are calculated using Maslen's method. For the axisymmetric inverse problem paraboloidal shock is chosen and the surface distribution of pressure is obtained.Keywords: Hypersonic flow, Inverse problem method
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30521102 Biomimetic Preparation of Nano Hydroxyapatite in Gelatin-Starch Matrix
Authors: M.Meskinfam, M. S. Sadjadi, H.Jazdarreh
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In this study, we report the synthesis and characterization of nanohydroxyapatite (nHAp) in gelatin-starch matrix via biomimetic method. Characterization of the samples was performed using X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FT-IR). The Size and morphology of the nHAp samples were determined using scanning and transmission electron microscopy (SEM and TEM). The results reveal that the shape and morphology of nHAp is influenced by presence of biopolymers as template. Carbonyl and amino groups from gelatin and hydroxyl from starch play crucial roles in HAp formation on the surface of gelatin-starch.Keywords: Biocomposite, Biomimetic , Nano Hydroxyapatite , Template.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25851101 Modeling the Effect of Spacer Orientation on Heat Transfer in Membrane Distillation
Authors: M. Shakaib, M. Ehtesham-ul Haq, I. Ahmed, R.M. Yunus
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Computational fluid dynamics (CFD) simulations carried out in this paper show that spacer orientation has a major influence on temperature patterns and on the heat transfer rates. The local heat flux values significantly vary from high to very low values at each filament when spacer touches the membrane surface. The heat flux profile is more uniform when spacer filaments are not in contact with the membrane thus making this arrangement more beneficial. The temperature polarization is also found to be less in this case when compared to the empty channel.Keywords: heat transfer, membrane distillation, spacer, temperature polarization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17111100 Analysis of Threats in Interoperability of Medical Devices
Authors: M. Sandhya, R. M. Madhumitha, Sharmila Sankar
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Interoperable medical devices (IMDs) face threats due to the increased attack surface accessible by interoperability and the corresponding infrastructure. Initiating networking and coordination functionalities primarily modify medical systems' security properties. Understanding the threats is a vital first step in ultimately crafting security solutions for such systems. The key to this problem is coming up with some common types of threats or attacks with those of security and privacy, and providing this information as a roadmap. This paper analyses the security issues in interoperability of devices and presents the main types of threats that have to be considered to build a secured system.
Keywords: Interoperability, threats, attacks, medical devices.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15131099 Comparative Finite Element Simulation of Nonlinear Vibrations and Sensor Output Voltage of Smart Piezolaminated Structures
Authors: Ruediger Schmidt, Thang Duy Vu
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Two geometrically nonlinear plate theories, based either on first- or third-order transverse shear deformation theory are used for finite element modeling and simulation of the transient response of smart structures incorporating piezoelectric layers. In particular the time histories of nonlinear vibrations and sensor voltage output of a thin beam with a piezoelectric patch bonded to the surface due to an applied step force are studied.
Keywords: Nonlinear vibrations, piezoelectric patches, sensor voltage output, smart structures.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19811098 Microstructure Changes of Machined Surfaceson Austenitic 304 Stainless Steel
Authors: Lin. Yan, Wenyu. Yang, Hongping. Jin, Zhiguang Wang
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This paper presents a experiment to estimate the influences of cutting conditions in microstructure changes of machining austenitic 304 stainless steel, especially for wear insert. The wear insert were prefabricated with a width of 0.5 mm. And the forces, temperature distribution, RS, and microstructure changes were measured by force dynamometer, infrared thermal camera, X-ray diffraction, XRD, SEM, respectively. The results told that the different combinations of machining condition have a significant influence on machined surface microstructure changes. In addition to that, the ANOVA and AOMwere used to tell the different influences of cutting speed, feed rate, and wear insert.Keywords: Microstructure Changes, Wear width, Stainless steel
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23161097 Effective Photodegradation of Tetracycline by a Heteropoly Acid/Graphene Oxide Nanocomposite Based on Uio-66
Authors: Anasheh Maridiroosi, Ali Reza Mahjoub, Hanieh Fakhri
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Heteropoly acid nanoparticles anchored on graphene oxide based on UiO-66 were synthesized via in-situ growth hydrothermal method and tested for photodegradation of a tetracycline as critical pollutant. Results showed that presence of graphene oxide and UiO-66 with high specific surface area, great electron mobility and various functional groups make an excellent support for heteropoly acid and improve photocatalytic efficiency up to 95% for tetracycline. Furthermore, total organic carbon (TOC) analysis verified 79% mineralization of this pollutant under optimum condition.
Keywords: Heteropoly acid, graphene oxide, MOF, tetracycline.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7401096 Structure-Phase States of Al-Si Alloy after Electron-Beam Treatment and Multicycle Fatigue
Authors: Krestina V. Alsaraeva, Victor E. Gromov, Sergey V. Konovalov, Anna A. Atroshkina
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Processing of Al-19.4Si alloy by high intensive electron beam has been carried out and multiple increases in fatigue life of the material have been revealed. Investigations of structure and surface modified layer destruction of Al-19.4Si alloy subjected to multicycle fatigue tests to fracture have been carried out by methods of scanning electron microscopy. The factors responsible for the increase of fatigue life of Al-19.4Si alloy have been revealed and analyzed.Keywords: Al-19.4Si alloy, high intensive electron beam, multicycle fatigue, structure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20061095 The Effect of Ion Nitriding and Carbonitriding on Fretting Fatigue of Steels
Authors: V. Linhart, M.
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The paper deals with the effect of ion nitriding and carbonitriding on fatigue strength of steel parts under the fretting conditions. Instrumented fatigue tests were carried out on surface treated flat bars from EA1N and EA4T steels with different strength. The chosen surfacing decrease importantly an unfavorable fretting effect. Nitridation suppressed the unfavorable effect of fretting almost entirely, while the influence of carbonitridation was less striking. The results were compared with those ones obtained on bars without surfacing. The causes of favorable influence of surfacing are discussed.Keywords: Carbonitriding, fatigue, fretting, nitriding, steel.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23581094 Discrete Tracking Control of Nonholonomic Mobile Robots: Backstepping Design Approach
Authors: Alexander S. Andreev, Olga A. Peregudova
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In this paper we propose a discrete tracking control of nonholonomic mobile robots with two degrees of freedom. The electromechanical model of a mobile robot moving on a horizontal surface without slipping, with two rear wheels controlled by two independent DC electric, and one front roal wheel is considered. We present backstepping design based on the Euler approximate discretetime model of a continuous-time plant. Theoretical considerations are verified by numerical simulation.
Keywords: Actuator Dynamics, Backstepping, Discrete-Time Controller, Lyapunov Function, Wheeled Mobile Robot.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20381093 Nanoindentation of Thin Films Prepared by Physical Vapor Deposition
Authors: Dhiflaoui Hafedh, Khlifi Kaouthar, Ben Cheikh Larbi Ahmed
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These Monolayer and multilayer coatings of CrN and AlCrN deposited on 100Cr6 (AISI 52100) substrate by PVD magnetron sputtering system. The microstructures of the coatings were characterized using atomic force microscopy (AFM). The AFM analysis revealed the presence of domes and craters that are uniformly distributed over all surfaces of the various layers. Nanoindentation measurement of CrN coating showed maximum hardness (H) and modulus (E) of 14 GPa and 190 GPa, respectively. The measured H and E values of AlCrN coatings were found to be 30 GPa and 382 GPa, respectively. The improved hardness in both the coatings was attributed mainly to a reduction in crystallite size and decrease in surface roughness. The incorporation of Al into the CrN coatings has improved both hardness and Young’s modulus.Keywords: CrN/AlCrN, coatings, hardness, nano-indentation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22121092 Finite Element Modelling of Ground Vibrations Due to Tunnelling Activities
Authors: Muhammad E. Rahman, Trevor Orr
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This paper presents the use of three-dimensional finite elements coupled with infinite elements to investigate the ground vibrations at the surface in terms of the peak particle velocity (PPV) due to construction of the first bore of the Dublin Port Tunnel. This situation is analysed using a commercially available general-purpose finite element package ABAQUS. A series of parametric studies is carried out to examine the sensitivity of the predicted vibrations to variations in the various input parameters required by finite element method, including the stiffness and the damping of ground. The results of this study show that stiffness has a more significant effect on the PPV rather than the damping of the ground.Keywords: Finite Elements, PPV, Tunnelling, Vibration
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32431091 A Numerical Model for Studying Convectional Lifting Processes in the Tropics
Authors: Chantawan Noisri, Robert Harold Buchanan Exell
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A simple model for studying convectional lifting processes in the tropics is described in this paper with some tests of the model in dry air. The model consists of the density equation, the wind equation, the vertical velocity equation, and the temperature equation. The model domain is two-dimensional with length 100 km and height 17.5 km. Plan for experiments to investigate the effects of the heating surface, the deep convection approximation and the treatment of velocities at the boundaries are discussed. Equations for the simplified treatment of moisture in the atmosphere in future numerical experiments are also given.Keywords: Numerical weather prediction, Finite differences, Convection lifting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12821090 Vehicle Aerodynamics: Drag Reduction by Surface Dimples
Authors: C. K. Chear, S. S. Dol
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For a bluff body, dimples behave like roughness elements in stimulating a turbulent boundary layer, leading to delayed flow separation, a smaller wake and lower form drag. This is very different in principle from the application of dimples to streamlined body, where any reduction in drag would be predominantly due to a reduction in skin friction. In the present work, a car model with different dimple geometry is simulated using k-ε turbulence modeling to determine its effect to the aerodynamics performance. Overall, the results show that the application of dimples manages to reduce the drag coefficient of the car model.
Keywords: Aerodynamics, Boundary Layer, Dimple, Drag, Kinetic Energy, Turbulence.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 63041089 Effect of Catalyst Preparation on the Performance of CaO-ZnO Catalysts for Transesterification
Authors: Pathravut Klinklom, Apanee Luengnaruemitchai, Samai Jai-In
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In this research, CaO-ZnO catalysts (with various Ca:Zn atomic ratios of 1:5, 1:3, 1:1, and 3:1) prepared by incipientwetness impregnation (IWI) and co-precipitation (CP) methods were used as a catalyst in the transesterification of palm oil with methanol for biodiesel production. The catalysts were characterized by several techniques, including BET method, CO2-TPD, and Hemmett Indicator. The effects of precursor concentration, and calcination temperature on the catalytic performance were studied under reaction conditions of a 15:1 methanol to oil molar ratio, 6 wt% catalyst, reaction temperature of 60°C, and reaction time of 8 h. At Ca:Zn atomic ratio of 1:3 gave the highest FAME value owing to a basic properties and surface area of the prepared catalyst.Keywords: CaO, ZnO, Biodiesel, Impregnation, Coprecipitation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26931088 Competitiveness and Pricing Policy Assessment for Resilience Surface Access System at Airports
Authors: Dimitrios J. Dimitriou
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Considering a worldwide tendency, air transports are growing very fast and many changes have taken place in planning, management and decision making process. Given the complexity of airport operation, the best use of existing capacity is the key driver of efficiency and productivity. This paper deals with the evaluation framework for the ground access at airports, by using a set of mode choice indicators providing key messages towards airport’s ground access performance. The application presents results for a sample of 12 European airports, illustrating recommendations to define policy and improve service for the air transport access chain.
Keywords: Air transport chain, airport ground access, airport access performance, airport policy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11161087 Magnetohydrodynamic Mixed Convective Flow in a Cavity
Authors: R.YadollahiFarsani, B. Ghasemi
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A magnetohydrodynamic mixed convective flow in a cavity was studied in this paper. The lower surface of cavity was heated from below whereas other walls of the cavity were thermally isolated. The governing two-dimensional flow equations have been solved by using finite volume code. The effects of magnetic field were studied on flow and temperature field and heat transfer performance at a wide range of parameters, Such as Hartmann (0≤Ha≤100) and Reynolds (1≤Re≤100) numbers. The results showed that as Hartman number increases the Nusselt number, representing heat transfer from the cavity decreases.Keywords: Cavity, Magnetic Field, Mixed Convection, Magnetohydrodynamic
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1570