Search results for: engineering parameters
3292 Thermodynamic Study for Aggregation Behavior of Hydrotropic Solution
Authors: Meghal Desai, Jigisha Parikh
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Aggregation behavior of sodium salicylate and sodium cumene sulfonate was studied in aqueous solution at different temperature. Specific conductivity and relative viscosity were measured at different temperature to find minimum hydrotropic concentration. The thermodynamic parameters (free energy, enthalpy and entropy) were evaluated in the temperature range of 30°C-70°C. The free energy decreased with increase in temperature. The aggregation was found to be exothermic in nature and favored by positive value of entropy.
Keywords: Hydrotropes, Enthalpy, Entropy, Free Energy, Minimum Hydrotropic Concentration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20063291 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 15853290 Thermal Evaluation of Printed Circuit Board Design Options and Voids in Solder Interface by a Simulation Tool
Authors: B. Arzhanov, A. Correia, P. Delgado, J. Meireles
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Quad Flat No-Lead (QFN) packages have become very popular for turners, converters and audio amplifiers, among others applications, needing efficient power dissipation in small footprints. Since semiconductor junction temperature (TJ) is a critical parameter in the product quality. And to ensure that die temperature does not exceed the maximum allowable TJ, a thermal analysis conducted in an earlier development phase is essential to avoid repeated re-designs process with huge losses in cost and time. A simulation tool capable to estimate die temperature of components with QFN package was developed. Allow establish a non-empirical way to define an acceptance criterion for amount of voids in solder interface between its exposed pad and Printed Circuit Board (PCB) to be applied during industrialization process, and evaluate the impact of PCB designs parameters. Targeting PCB layout designer as an end user for the application, a user-friendly interface (GUI) was implemented allowing user to introduce design parameters in a convenient and secure way and hiding all the complexity of finite element simulation process. This cost effective tool turns transparent a simulating process and provides useful outputs after acceptable time, which can be adopted by PCB designers, preventing potential risks during the design stage and make product economically efficient by not oversizing it. This article gathers relevant information related to the design and implementation of the developed tool, presenting a parametric study conducted with it. The simulation tool was experimentally validated using a Thermal-Test-Chip (TTC) in a QFN open-cavity, in order to measure junction temperature (TJ) directly on the die under controlled and knowing conditions. Providing a short overview about standard thermal solutions and impacts in exposed pad packages (i.e. QFN), accurately describe the methods and techniques that the system designer should use to achieve optimum thermal performance, and demonstrate the effect of system-level constraints on the thermal performance of the design.Keywords: Quad Flat No-Lead packages, exposed pads, junction temperature, thermal management and measurements.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19283289 Modeling of Dielectric Heating in Radio- Frequency Applicator Optimized for Uniform Temperature by Means of Genetic Algorithms
Authors: Camelia Petrescu, Lavinia Ferariu
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The paper presents an optimization study based on genetic algorithms (GA-s) for a radio-frequency applicator used in heating dielectric band products. The weakly coupled electro-thermal problem is analyzed using 2D-FEM. The design variables in the optimization process are: the voltage of a supplementary “guard" electrode and six geometric parameters of the applicator. Two objective functions are used: temperature uniformity and total active power absorbed by the dielectric. Both mono-objective and multiobjective formulations are implemented in GA optimization.Keywords: Dielectric heating, genetic algorithms, optimization, RF applicators.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19313288 Geotechnical Design of Bridge Foundations and Approaches in Hilly Granite Formation
Authors: Q. J. Yang
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This paper presents a case study of geotechnical design of bridge foundations and approaches in hilly granite formation in northern New South Wales of Australia. Firstly, the geological formation and existing cut slope conditions which have high risks of rock fall will be described. The bridge has three spans to be constructed using balanced cantilever method with a middle span of 150 m. After concept design option engineering, it was decided to change from pile foundation to pad footing with ground anchor system to optimize the bridge foundation design. The geotechnical design parameters were derived after two staged site investigations. The foundation design was carried out to satisfy both serviceability limit state and ultimate limit state during construction and in operation. It was found that the pad footing design was governed by serviceability limit state design loading cases. The design of bridge foundation also considered presence of weak rock layer intrusion and a layer of “no core” to ensure foundation stability. The precast mass concrete block system was considered for the retaining walls for the bridge approaches to resolve the constructability issue over hilly terrain. The design considered the retaining wall block sliding stability, while the overturning and internal stabilities are satisfied.Keywords: Pad footing, hilly formation, stability, block works.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16153287 Exponentiated Transmuted Weibull Distribution A Generalization of the Weibull Distribution
Authors: Abd El Hady N. Ebraheim
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This paper introduces a new generalization of the two parameter Weibull distribution. To this end, the quadratic rank transmutation map has been used. This new distribution is named exponentiated transmuted Weibull (ETW) distribution. The ETW distribution has the advantage of being capable of modeling various shapes of aging and failure criteria. Furthermore, eleven lifetime distributions such as the Weibull, exponentiated Weibull, Rayleigh and exponential distributions, among others follow as special cases. The properties of the new model are discussed and the maximum likelihood estimation is used to estimate the parameters. Explicit expressions are derived for the quantiles. The moments of the distribution are derived, and the order statistics are examined.
Keywords: Exponentiated, Inversion Method, Maximum Likelihood Estimation, Transmutation Map.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 34713286 Analysis of Palm Perspiration Effect with SVM for Diabetes in People
Authors: Hamdi Melih Saraoğlu, Muhlis Yıldırım, Abdurrahman Özbeyaz, Feyzullah Temurtas
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In this research, the diabetes conditions of people (healthy, prediabete and diabete) were tried to be identified with noninvasive palm perspiration measurements. Data clusters gathered from 200 subjects were used (1.Individual Attributes Cluster and 2. Palm Perspiration Attributes Cluster). To decrase the dimensions of these data clusters, Principal Component Analysis Method was used. Data clusters, prepared in that way, were classified with Support Vector Machines. Classifications with highest success were 82% for Glucose parameters and 84% for HbA1c parametres.
Keywords: Palm perspiration, Diabetes, Support Vector Machine, Classification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19473285 Higher Order Statistics for Identification of Minimum Phase Channels
Authors: Mohammed Zidane, Said Safi, Mohamed Sabri, Ahmed Boumezzough
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This paper describes a blind algorithm, which is compared with two another algorithms proposed in the literature, for estimating of the minimum phase channel parameters. In order to identify blindly the impulse response of these channels, we have used Higher Order Statistics (HOS) to build our algorithm. The simulation results in noisy environment, demonstrate that the proposed method could estimate the phase and magnitude with high accuracy of these channels blindly and without any information about the input, except that the input excitation is identically and independent distribute (i.i.d) and non-Gaussian.
Keywords: System Identification, Higher Order Statistics, Communication Channels.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16723284 Geometrically Non-Linear Free Vibration Analysis of Functionally Graded Rectangular Plates
Authors: Boukhzer Abdenbi, El Bikri Khalid, Benamar Rhali
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In the present study, the problem of geometrically non-linear free vibrations of functionally graded rectangular plates (FGRP) is studied. The theoretical model, previously developed and based on Hamilton’s principle, is adapted here to determine the fundamental non-linear mode shape of these plates. Frequency parameters, displacements and stress are given for various power-law distributions of the volume fractions of the constituents and various aspect ratios. Good agreement with previous published results is obtained in the case of linear and non-linear analyses.
Keywords: Non-linear vibration, functionally graded materials, rectangular plates.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22463283 Developing a New Vibration Analysis Calculative Method for Esfahan Subway Train and Railways Design, Manufacturing, and Construction
Authors: Omid A. Zargar
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The simulated mass and spring method evaluation for subway or railways construction and installation systems have a wide application in rail industries. This kind of design should be optimizing all related parameters to reduce the amount of vibration in cities, homelands, historical zones and other critical locations. Finite element method could help us a lot to analysis such applications with an excellent accuracy but always developing some simple, fast and user friendly evaluation method required in subway industrial applications. In addition, process parameter optimization extremely required in railway industries to achieve some optimal design of railways with maximum safety, reliability and performance. Furthermore, it is important to reduce vibrations and further related maintenance costs as well as possible. In this paper a simple but useful simulated mass and spring evaluation system developed for Esfahan subway construction. Besides, some of related recent patent and innovations in rail world industries like Suspension mass tuned vibration reducer, short sleeper vibration attenuation fastener and Airtight track vibration-noise reducing fastener discussed in details.
Keywords: Subway construction engineering, natural frequency, operation frequency, vibration analysis, polyurethane layer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23593282 Manufacture of Electroless Nickel/YSZ Composite Coatings
Authors: N. Bahiyah Baba, W. Waugh, A.M. Davidson
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The paper discusses optimising work on a method of processing ceramic / metal composite coatings for various applications and is based on preliminary work on processing anodes for solid oxide fuel cells (SOFCs). The composite coating is manufactured by the electroless co-deposition of nickel and yttria stabilised zirconia (YSZ) simultaneously on to a ceramic substrate. The effect on coating characteristics of substrate surface treatments and electroless nickel bath parameters such as pH and agitation methods are also investigated. Characterisation of the resulting deposit by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) is also discussed.
Keywords: Electroless deposition, nickel, YSZ, composite
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25693281 Main Control Factors of Fluid Loss in Drilling and Completion in Shunbei Oilfield by Unmanned Intervention Algorithm
Authors: Peng Zhang, Lihui Zheng, Xiangchun Wang, Xiaopan Kou
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Quantitative research on the main control factors of lost circulation has few considerations and single data source. Using Unmanned Intervention Algorithm to find the main control factors of lost circulation adopts all measurable parameters. The degree of lost circulation is characterized by the loss rate as the objective function. Geological, engineering and fluid data are used as layers, and 27 factors such as wellhead coordinates and Weight on Bit (WOB) used as dimensions. Data classification is implemented to determine function independent variables. The mathematical equation of loss rate and 27 influencing factors is established by multiple regression method, and the undetermined coefficient method is used to solve the undetermined coefficient of the equation. Only three factors in t-test are greater than the test value 40, and the F-test value is 96.557%, indicating that the correlation of the model is good. The funnel viscosity, final shear force and drilling time were selected as the main control factors by elimination method, contribution rate method and functional method. The calculated values of the two wells used for verification differ from the actual values by -3.036 m3/h and -2.374 m3/h, with errors of 7.21% and 6.35%. The influence of engineering factors on the loss rate is greater than that of funnel viscosity and final shear force, and the influence of the three factors is less than that of geological factors. The best combination of funnel viscosity, final shear force and drilling time is obtained through quantitative calculation. The minimum loss rate of lost circulation wells in Shunbei area is 10 m3/h. It can be seen that man-made main control factors can only slow down the leakage, but cannot fundamentally eliminate it. This is more in line with the characteristics of karst caves and fractures in Shunbei fault solution oil and gas reservoir.
Keywords: Drilling fluid, loss rate, main controlling factors, Unmanned Intervention Algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4013280 Fuzzy Controller Design for Ball and Beam System with an Improved Ant Colony Optimization
Authors: Yeong-Hwa Chang, Chia-Wen Chang, Hung-Wei Lin, C.W. Tao
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In this paper, an improved ant colony optimization (ACO) algorithm is proposed to enhance the performance of global optimum search. The strategy of the proposed algorithm has the capability of fuzzy pheromone updating, adaptive parameter tuning, and mechanism resetting. The proposed method is utilized to tune the parameters of the fuzzy controller for a real beam and ball system. Simulation and experimental results indicate that better performance can be achieved compared to the conventional ACO algorithms in the aspect of convergence speed and accuracy.Keywords: Ant colony algorithm, Fuzzy control, ball and beamsystem
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21963279 Detailed Phenomenological Study of 14N Elastically Scattered on 12C in a wide Energy Range
Authors: Sh. Hamada, N. Burtebayev, N. Amangeldi, A. Amar
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An experiment was performed with a 24.5 MeV 14N beam on a 12C target in the cyclotron DC-60 located in Astana, Kazakhstan, to study the elastic scattering of 14N on 12C; the scattering was also analyzed at different energies for tracking the phenomenon of remarkable structure at large angles. Its aims were to extend the measurements to very large angles, and attempt to uniquely identify the elastic scattering potential. Good agreement between the theoretical and experimental data has been obtained with suitable optical potential parameters. Optical model calculations with l -dependent imaginary potentials were also applied to the data and relatively good agreement was found.Keywords: Optical Potential Codes, Elastic Scattering, SPIVALCode.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15633278 Determination of Regimes of the Equivalent Generator Based On Projective Geometry: The Generalized Equivalent Generator
Authors: A. A. Penin
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Requirements that should be met when determining the regimes of circuits with variable elements are formulated. The interpretation of the variations in the regimes, based on projective geometry, enables adequate expressions for determining and comparing the regimes to be derived. It is proposed to use as the parameters of a generalized equivalent generator of an active two-pole with changeable resistor such load current and voltage which provide the current through this resistor equal to zero.
Keywords: Equivalent generator, geometric circuits theory, circuits regimes, load characteristics, variable elements.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13943277 Estimate of Maximum Expected Intensity of One-Half-Wave Lines Dancing
Authors: A. Bekbaev, M. Dzhamanbaev, R. Abitaeva, A. Karbozova, G. Nabyeva
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In this paper, the regression dependence of dancing intensity from wind speed and length of span was established due to the statistic data obtained from multi-year observations on line wires dancing accumulated by power systems of Kazakhstan and the Russian Federation. The lower and upper limitations of the equations parameters were estimated, as well as the adequacy of the regression model. The constructed model will be used in research of dancing phenomena for the development of methods and means of protection against dancing and for zoning plan of the territories of line wire dancing.Keywords: Power lines, line wire dancing, dancing intensity, regression equation, dancing area intensity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12103276 The Effect of Chemical Treatment on TL Glow Curves of CdS/ZnS Thin Films Deposited by Vacuum Deposition Method
Authors: N. Dahbi, D-E. Arafah
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The effect of chemical treatment in CdCl2 and thermal annealing in 400°C, on the defect structures of potentially useful ZnS\CdS solar cell thin films deposited onto quartz substrate and prepared by vacuum deposition method was studied using the Thermoluminesence (TL) techniques. A series of electron and hole traps are found in the various deposited samples studied. After annealing, however, it was observed that the intensity and activation energy of TL signal increases with loss of the low temperature electron traps.Keywords: CdS, chemical treatment, heat treatment, Thermoluminescence, trapping parameters, thin film, vacuumdeposition, ZnS
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15233275 Critical Velocities for Particle Transport from Experiments and CFD Simulations
Authors: Sajith Sajeev, Brenton McLaury, Siamack Shirazi
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In the petroleum industry, solid particles are often present along with the produced fluids. It is imperative to keep particles from accumulating in flow lines. In this study, various experiments are conducted to study sand particle transport, where critical velocity is defined as the average fluid velocity to keep particles continuously moving. Many parameters related to the fluid, particles and pipe affect the transport process. Experimental results are presented varying the particle concentration. Additionally, CFD simulations using a discrete element modeling (DEM) approach are presented to compare with experimental result.Keywords: Particle transport, critical velocity, CFD, DEM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12123274 Performance Comparison of Prim’s and Ant Colony Optimization Algorithm to Select Shortest Path in Case of Link Failure
Authors: Rimmy Yadav, Avtar Singh
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Ant Colony Optimization (ACO) is a promising modern approach to the unused combinatorial optimization. Here ACO is applied to finding the shortest during communication link failure. In this paper, the performances of the prim’s and ACO algorithm are made. By comparing the time complexity and program execution time as set of parameters, we demonstrate the pleasant performance of ACO in finding excellent solution to finding shortest path during communication link failure.Keywords: Ant colony optimization, link failure, prim’s algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21843273 Ray Tracing Modified 3D Image Method Simulation of Picocellular Propagation Channel Environment
Authors: F. Alwafie
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In this paper, we present the simulation of the propagation characteristics of the picocellular propagation channel environment. The first aim has been to find a correct description of the environment for received wave.
The result of the first investigations is that the environment of the indoor wave significantly changes as we change the electric parameters of material constructions. A modified 3D ray tracing image method tool has been utilized for the coverage prediction. A detailed analysis of the dependence of the indoor wave on the wideband characteristics of the channel: root mean square (RMS) delay spread characteristics and Mean excess delay, is also investigated.
Keywords: Propagation, Ray Tracing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19533272 The Effect of X-Ray on Plasma and Erythrocyte Concentration of Zn and Cu in Radiology Staff of Tehran Oil Hospital
Authors: L. Nekoozad, M. Salehi Barough, B. Salmasian
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Introduction: Some parameters should be considered to investigate the chronic effects of radiation absorption in radiation workers. Trace elements are parameters which small changes in them can cause significant effects on live systems. The role of trace element concentration in human health is significant. These elements play an important role in the developing and functioning of the immune system, cellular respiration, and oxidation processes. Considering the importance and necessity of this issue and few studies, measurements of concentration changes of these elements due to the absorbed dose are important. Purpose: This study aimed to determine the biological effects of occupational dose absorption on plasma and erythrocyte concentration of Zn and Cu in the radiology staff of Tehran Oil Hospital. Material and methods: In this analytical-comparative study, 72 people have entered. 36 people (18 males and 18 females) were selected as radiology staff in the diagnostic and therapeutic departments of Tehran Oil Hospital. And 36 people (18 males and 18 females) were selected as general section staff in the same hospital as a control group. Radiology and control groups’ age and sex were matched. 10 ml of venous blood was taken from all people. An atomic absorption spectrometer was used to obtain zinc and copper plasma concentrations. Levine test was used to compare these results validity. Results: The mean concentrations of copper and zinc were measured as 0.951 and 0.754 mg/L in the plasma phase and 3.2 and 0.401 mg/L in the RBC phase for the radiology group. Copper and zinc average concentrations, respectively 0.976 and 0.813 mg/L in the plasma phase and 2.906 and 0.476 mg/L in the RBC phase, were measured for the control group. These elements Concentrations in the plasma phase were significantly different from that of the control group, but the concentrations in the red blood cell phase did not show a significant difference compared to the control group. In comparison, a separate comparison between men and women in the experimental and control groups showed a significant difference in the values of the elements mentioned. With a significant increase in samples, a better justification than the available statistical results can be extracted. Conclusions: Within this study results, chronic occupational probabilistic absorption destructive effects (even within the permitted range) on blood trace element concentration have been confirmed.
Keywords: Chronic absorption, atomic absorption spectrometry, radiology staff, trace element concentration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7143271 A Brief Study about Nonparametric Adherence Tests
Authors: Vinicius R. Domingues, Luan C. S. M. Ozelim
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The statistical study has become indispensable for various fields of knowledge. Not any different, in Geotechnics the study of probabilistic and statistical methods has gained power considering its use in characterizing the uncertainties inherent in soil properties. One of the situations where engineers are constantly faced is the definition of a probability distribution that represents significantly the sampled data. To be able to discard bad distributions, goodness-of-fit tests are necessary. In this paper, three non-parametric goodness-of-fit tests are applied to a data set computationally generated to test the goodness-of-fit of them to a series of known distributions. It is shown that the use of normal distribution does not always provide satisfactory results regarding physical and behavioral representation of the modeled parameters.Keywords: Kolmogorov-Smirnov, Anderson-Darling, Cramer-Von-Mises, Nonparametric adherence tests.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18433270 Measurement of Temperature, Humidity and Strain Variation Using Bragg Sensor
Authors: Amira Zrelli, Tahar Ezzeddine
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Measurement and monitoring of temperature, humidity and strain variation are very requested in great fields and areas such as structural health monitoring (SHM) systems. Currently, the use of fiber Bragg grating sensors (FBGS) is very recommended in SHM systems due to the specifications of these sensors. In this paper, we present the theory of Bragg sensor, therefore we try to measure the efficient variation of strain, temperature and humidity (SV, ST, SH) using Bragg sensor. Thus, we can deduce the fundamental relation between these parameters and the wavelength of Bragg sensor.Keywords: Optical fiber, strain, temperature, humidity, measurement, Bragg sensor, SHM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11403269 Rational Structure of Panel with Curved Plywood Ribs
Authors: Janis Šliseris, Karlis Rocens
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Optimization of rational geometrical and mechanical parameters of panel with curved plywood ribs is considered in this paper. The panel consists of cylindrical plywood ribs manufactured from Finish plywood, upper and bottom plywood flange, stiffness diaphragms. Panel is filled with foam. Minimal ratio of structure self weight and load that could be applied to structure is considered as rationality criteria. Optimization is done, by using classical beam theory without nonlinearities. Optimization of discreet design variables is done by Genetic algorithm.Keywords: Curved plywood ribs, genetic algorithm, rationalparameters of ribbed panel, structure optimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17393268 The Effect of Micro Tools Fabricated Dent on Alumina/Alumina Oxide Interface
Authors: Taposh Roy, Dipankar Choudhury, Belinda Pingguan-Murphy
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The tribological outcomes of micro dent are found to be outstanding in many engineering and natural surfaces. Ceramic (Al2O3) is considered one of the most potential material to bearing surfaces particularly, artificial hip or knee implant. A well-defined micro dent on alumina oxide interface could further decrease friction and wear rate, thus increase their stability and durability. In this study we fabricated circular micro dent surface profiles (Dia: 400µm, Depth 20µm, P: 1.5mm; Dia: 400µm, Depth 20µm, P: 2mm) on pure Al2O3 (99.6%) substrate by using a micro tool machines. A preliminary tribological experiment was carried out to compare friction coefficient of these fabricated dent surfaces with that of non-textured surfaces. The experiment was carried on well know pin-on-disk specimens while other experimental parameters such as hertz pressure, speed, lubrication, and temperature were maintained to standard of simulated hip joints condition. The experiment results revealed that micro dent surface texture reduced 15%, 8% and 4% friction coefficient under 0.132,0.162, 0.187 GPa contact pressure respectively. Since this is a preliminary tribological study, we will pursue further experiments considering higher ranges of dent profiles and longer run experiments. However, the preliminary results confirmed the suitability of fabricating dent profile to ceramic surfaces by using micro tooling, and also their improved tribological performance in simulated hip joints.
Keywords: Micro dent, tribology, ceramic on ceramic hipjoints.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23443267 Induced Acyclic Path Decomposition in Graphs
Authors: Abraham V. M., I. Sahul Hamid
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A decomposition of a graph G is a collection ψ of graphs H1,H2, . . . , Hr of G such that every edge of G belongs to exactly one Hi. If each Hi is either an induced path in G, then ψ is called an induced acyclic path decomposition of G and if each Hi is a (induced) cycle in G then ψ is called a (induced) cycle decomposition of G. The minimum cardinality of an induced acyclic path decomposition of G is called the induced acyclic path decomposition number of G and is denoted by ¤Çia(G). Similarly the cyclic decomposition number ¤Çc(G) is defined. In this paper we begin an investigation of these parameters.Keywords: Cycle decomposition, Induced acyclic path decomposition, Induced acyclic path decomposition number.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15753266 Influence of Various Factors on Stability of CoSPc in LPG Sweetening Process
Authors: Ali Samadi Afshar, Hamed Harrafi, S.M.Javad Gharib Zahedi
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IFP Group Technology “Sulfrex process" was used in Iran-s South Pars Gas Complex Refineries for removing sulfur compounds such as mercaptans, carbonyl sulfide and hydrogen sulfide, which uses sulfonated cobalt phthalocyanine dispersed in alkaline solution as catalyst. In this technology, catalyst and alkaline solution were used circularly. However the stability of catalyst due to effect of some parameters would reduce with the running of the unit and therefore sweetening efficiency would be decreased. Hence, the aim of this research is study the factors effecting on the stability of catalyst.Keywords: sulfonated cobalt phthalocyanine, mercaptans, stability, catalyst, sulfur.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 24883265 Modelling Extreme Temperature in Malaysia Using Generalized Extreme Value Distribution
Authors: Husna Hasan, Norfatin Salam, Mohd Bakri Adam
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Extreme temperature of several stations in Malaysia is modelled by fitting the monthly maximum to the Generalized Extreme Value (GEV) distribution. The Mann-Kendall (MK) test suggests a non-stationary model. Two models are considered for stations with trend and the Likelihood Ratio test is used to determine the best-fitting model. Results show that half of the stations favour a model which is linear for the location parameters. The return level is the level of events (maximum temperature) which is expected to be exceeded once, on average, in a given number of years, is obtained.Keywords: Extreme temperature, extreme value, return level.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28353264 Reliable Face Alignment Using Two-Stage AAM
Authors: Sunho Ki, Daehwan Kim, Seongwon Cho, Sun-Tae Chung, Jaemin Kim, Yun-Kwang Hong, Chang Joon Park, Dongmin Kwon, Minhee Kang, Yusung Kim, Younghan Yoon
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AAM (active appearance model) has been successfully applied to face and facial feature localization. However, its performance is sensitive to initial parameter values. In this paper, we propose a two-stage AAM for robust face alignment, which first fits an inner face-AAM model to the inner facial feature points of the face and then localizes the whole face and facial features by optimizing the whole face-AAM model parameters. Experiments show that the proposed face alignment method using two-stage AAM is more reliable to the background and the head pose than the standard AAM-based face alignment method.Keywords: AAM, Face Alignment, Feature Extraction, PCA
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14773263 The Effects of Tissue Optical Parameters and Interface Reflectivity on Light Diffusion in Biological Tissues
Authors: MA. Ansari
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In cancer progress, the optical properties of tissues like absorption and scattering coefficient change, so by these changes, we can trace the progress of cancer, even it can be applied for pre-detection of cancer. In this paper, we investigate the effects of changes of optical properties on light penetrated into tissues. The diffusion equation is widely used to simulate light propagation into biological tissues. In this study, the boundary integral method (BIM) is used to solve the diffusion equation. We illustrate that the changes of optical properties can modified the reflectance or penetrating light.Keywords: Diffusion equation, boundary element method, refractive index
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2017