Search results for: Machining stability.
581 A Servo Control System Using the Loop Shaping Design Procedure
Authors: Naohiro Ban, Hiromitsu Ogawa, Manato Ono, Yoshihisa Ishida
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This paper describes an expanded system for a servo system design by using the Loop Shaping Design Procedure (LSDP). LSDP is one of the H∞ design procedure. By conducting Loop Shaping with a compensator and robust stabilization to satisfy the index function, we get the feedback controller that makes the control system stable. In this paper, we propose an expanded system for a servo system design and apply to the DC motor. The proposed method performs well in the DC motor positioning control. It has no steady-state error in the disturbance response and it has robust stability.Keywords: Loop Shaping Design Procedure (LSDP), servosystem, DC motor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2410580 Bifurcation Method for Solving Positive Solutions to a Class of Semilinear Elliptic Equations and Stability Analysis of Solutions
Authors: Hailong Zhu, Zhaoxiang Li
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Semilinear elliptic equations are ubiquitous in natural sciences. They give rise to a variety of important phenomena in quantum mechanics, nonlinear optics, astrophysics, etc because they have rich multiple solutions. But the nontrivial solutions of semilinear equations are hard to be solved for the lack of stabilities, such as Lane-Emden equation, Henon equation and Chandrasekhar equation. In this paper, bifurcation method is applied to solving semilinear elliptic equations which are with homogeneous Dirichlet boundary conditions in 2D. Using this method, nontrivial numerical solutions will be computed and visualized in many different domains (such as square, disk, annulus, dumbbell, etc).
Keywords: Semilinear elliptic equations, positive solutions, bifurcation method, isotropy subgroups.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1648579 Choice of Exchange Rate Regimes: Case of Ex-Yugoslavia Countries
Authors: Ivan Lovrinović, Gordana Kordić, Martina Nakić
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There are little subjects in macroeconomics that are so widely discussed, but at the same time controversial and without a clear solution such as the choice of exchange rate regime. National authorities need to take into consideration numerous fundamentals, trying to fulfil goals of economic growth, low and stable inflation and international stability. This paper focuses on the countries of ex- Yugoslavia and their exchange rate history as independent states. We follow the development of the regimes in 6 countries during the transition through the financial crisis of the second part of the 2000s to the prospects of their final goal: full membership in the European Union. Main question is to what extent has the exchange regime contributed to their economic success, considering other objective factors.Keywords: European Union, exchange rate regime, ex- Yugoslavia countries
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1954578 Considerations for Effectively Using Probability of Failure as a Means of Slope Design Appraisal for Homogeneous and Heterogeneous Rock Masses
Authors: Neil Bar, Andrew Heweston
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Probability of failure (PF) often appears alongside factor of safety (FS) in design acceptance criteria for rock slope, underground excavation and open pit mine designs. However, the design acceptance criteria generally provide no guidance relating to how PF should be calculated for homogeneous and heterogeneous rock masses, or what qualifies a ‘reasonable’ PF assessment for a given slope design. Observational and kinematic methods were widely used in the 1990s until advances in computing permitted the routine use of numerical modelling. In the 2000s and early 2010s, PF in numerical models was generally calculated using the point estimate method. More recently, some limit equilibrium analysis software offer statistical parameter inputs along with Monte-Carlo or Latin-Hypercube sampling methods to automatically calculate PF. Factors including rock type and density, weathering and alteration, intact rock strength, rock mass quality and shear strength, the location and orientation of geologic structure, shear strength of geologic structure and groundwater pore pressure influence the stability of rock slopes. Significant engineering and geological judgment, interpretation and data interpolation is usually applied in determining these factors and amalgamating them into a geotechnical model which can then be analysed. Most factors are estimated ‘approximately’ or with allowances for some variability rather than ‘exactly’. When it comes to numerical modelling, some of these factors are then treated deterministically (i.e. as exact values), while others have probabilistic inputs based on the user’s discretion and understanding of the problem being analysed. This paper discusses the importance of understanding the key aspects of slope design for homogeneous and heterogeneous rock masses and how they can be translated into reasonable PF assessments where the data permits. A case study from a large open pit gold mine in a complex geological setting in Western Australia is presented to illustrate how PF can be calculated using different methods and obtain markedly different results. Ultimately sound engineering judgement and logic is often required to decipher the true meaning and significance (if any) of some PF results.
Keywords: Probability of failure, point estimate method, Monte-Carlo simulations, sensitivity analysis, slope stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1198577 Energy-Efficient Sensing Concept for a Micromachined Yaw Rate Sensor
Authors: D. Oshinubi, M. Rocznik, K. Dostert
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The need for micromechanical inertial sensors is increasing in future electronic stability control (ESC) and other positioning, navigation and guidance systems. Due to the rising density of sensors in automotive and consumer devices the goal is not only to get high performance, robustness and smaller package sizes, but also to optimize the energy management of the overall sensor system. This paper presents an evaluation concept for a surface micromachined yaw rate sensor. Within this evaluation concept an energy-efficient operation of the drive mode of the yaw rate sensor is enabled. The presented system concept can be realized within a power management subsystem.Keywords: inertial sensors, micromachined gyros, gyro sensing concepts, power management, FPGA
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1506576 Boundary Effect on the Onset of Marangoni Convection with Internal Heat Generation
Authors: Norihan Md Arifin, Norfifah Bachok
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The onset of Marangoni convection in a horizontal fluid layer with internal heat generation overlying a solid layer heated from below is studied. The upper free surface of a fluid is nondeformable and the bottom boundary are rigid and no-slip. The resulting eigenvalue problem is solved exactly. The critical values of the Marangoni numbers for the onset of Marangoni convection are calculated and the latter is found to be critically dependent on the internal heating, depth ratio and conductivity ratio. The effects of the thermal conductivity and the thickness of the solid plate on the onset of convective instability with internal heating are studied in detail.Keywords: Linear stability, Marangoni convection, Internal Heatgeneration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1475575 Project and Module Based Teaching and Learning
Authors: Jingyu Hou
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This paper proposes a new teaching and learning approach-project and module based teaching and learning (PMBTL). The PMBTL approach incorporates the merits of project/problem based and module based learning methods, and overcomes the limitations of these methods. The correlation between teaching, learning, practice and assessment is emphasized in this approach, and new methods have been proposed accordingly. The distinct features of these new methods differentiate the PMBTL approach from conventional teaching approaches. Evaluation of this approach on practical teaching and learning activities demonstrates the effectiveness and stability of the approach in improving the performance and quality of teaching and learning. The approach proposed in this paper is also intuitive to the design of other teaching units.
Keywords: Computer science education, project and module based, software engineering.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3452574 An Optical Sensing Film for Fe(III) Determination Based on 1,1′- diethyl 2,2′- cyanine Iodide Immobilized in Nafion Film
Authors: K. Kajsanthia, J. Wittayakun, S. Prayoonpokarach
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An optical chemical sensing film based on immobilizing of 1,1′- diethyl 2,2′-cyanine (pseudocyanine iodide) in nafion film was developed for the determination of Fe(III). The sensing film was homogeneous, transparent, and mechanically stable. Decrease of the absorbance measured at 518 nm was observed when the sensing film was immersed in a solution of Fe(III). The optimum response of the sensing film to Fe(III) was obtained in a solution with pH 4.0. Linear calibration curve over an Fe(III) concentration range of 1-30 ppm with a limit of detection of 0.71 ppm was obtained. Cd(II) is the major interference. The sensing film exhibited good stability for 2 months and high reproducibility. The proposed method was applied for the determination of Fe(III) in water samples with satisfactory results.Keywords: iron(III), _nafion, optical sensing film, pseudocyanine iodide
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1476573 Low-Cost and Highly Accurate Motion Models for Three-Dimensional Local Landmark-based Autonomous Navigation
Authors: Gheorghe Galben, Daniel N. Aloi
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Recently, the Spherical Motion Models (SMM-s) have been introduced [1]. These new models have been developed for 3D local landmark-base Autonomous Navigation (AN). This paper is revealing new arguments and experimental results to support the SMM-s characteristics. The accuracy and the robustness in performing a specific task are the main concerns of the new investigations. To analyze their performances of the SMM-s, the most powerful tools of estimation theory, the extended Kalman filter (EKF) and unscented Kalman filter (UKF), which give the best estimations in noisy environments, have been employed. The Monte Carlo validation implementations used to test the stability and robustness of the models have been employed as well.
Keywords: Autonomous navigation, extended kalman filter, unscented kalman filter, localization algorithms.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1311572 MP-SMC-I Method for Slip Suppression of Electric Vehicles under Braking
Authors: Tohru Kawabe
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In this paper, a new SMC (Sliding Mode Control) method with MP (Model Predictive Control) integral action for the slip suppression of EV (Electric Vehicle) under braking is proposed. The proposed method introduce the integral term with standard SMC gain , where the integral gain is optimized for each control period by the MPC algorithms. The aim of this method is to improve the safety and the stability of EVs under braking by controlling the wheel slip ratio. There also include numerical simulation results to demonstrate the effectiveness of the method.Keywords: Sliding Mode Control, Model Predictive Control, Integral Action, Electric Vehicle, Slip suppression.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2257571 Robust Adaptive Observer Design for Lipschitz Class of Nonlinear Systems
Authors: M. Pourgholi, V.J.Majd
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This paper addresses parameter and state estimation problem in the presence of the perturbation of observer gain bounded input disturbances for the Lipschitz systems that are linear in unknown parameters and nonlinear in states. A new nonlinear adaptive resilient observer is designed, and its stability conditions based on Lyapunov technique are derived. The gain for this observer is derived systematically using linear matrix inequality approach. A numerical example is provided in which the nonlinear terms depend on unmeasured states. The simulation results are presented to show the effectiveness of the proposed method.
Keywords: Adaptive observer, linear matrix inequality, nonlinear systems, nonlinear observer, resilient observer, robust estimation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2613570 Modelling of a Stress-Strain State of Screws of Transpedicular Spine Fixation System
Authors: Oleksandr Poliakov, Genadiy Olinichenko, Yevgen Pashkov, Vadym Kramar, Mykhaylo Kalinin
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For maintenance of a spine stability during the postoperative period a transpedicular fixing of its elements is often used. Usually the transpedicular systems are formed of rods which as a result form a design of the frame type, fastening by screws to vertebras. Such design should be rigid and perceive loadings operating from the spine without essential deformations. From the perfection point of view of known designs their stress whole, and each of elements, in particular is of interest. In this study the modeling of the transpedicular screw is performed and estimation of its deformations taking into account interaction with a vertebra body having variable structure is made.Keywords: Spine, screw, stress-strain state, transpedicular fixation system, vertebra
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1524569 Gas Permeation Behavior of Single and Mixed Gas Components Using an Asymmetric Ceramic Membrane
Authors: Ngozi Nwogu, Edward Gobina
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A dip-coating process has been used to form an asymmetric silica membrane with improved membrane performance and reproducibility. First, we deposited repeatedly silica on top of a commercial alumina membrane support to improve its structural make up. The membrane is further processed under clean room conditions to avoid dust impurity and subsequent drying in an oven for high thermal, chemical and physical stability. The resulting asymmetric membrane exhibits a gradual change in the membrane layer thickness. Compared to the support, the dual-layer process improves the gas flow rates. For the scientific applications for natural gas purification, CO2, CH4 and H2 gas flow rates were. In addition, the membrane selectively separated hydrogen.Keywords: Gas permeation, Silica membrane, separation factor, membrane layer thickness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2387568 Discontinuous Feedback Linearization of an Electrically Driven Fast Robot Manipulator
Authors: A. Izadbakhsh, M. M. Fateh, M. A. Sadrnia
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A multivariable discontinuous feedback linearization approach is proposed to position control of an electrically driven fast robot manipulator. A desired performance is achieved by selecting a useful controller and suitable sampling rate and considering saturation for actuators. There is a high flexibility to apply the proposed control approach on different electrically driven manipulators. The control approach can guarantee the stability and satisfactory tracking performance. A PUMA 560 robot driven by geared permanent magnet dc motors is simulated. The simulation results show a desired performance for control system under technical specifications.
Keywords: Fast robot, feedback linearization, multivariabledigital control, PUMA560.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1958567 Information Fusion as a Means of Forecasting Expenditures for Regenerating Complex Investment Goods
Authors: Steffen C. Eickemeyer, Tim Borcherding, Peter Nyhuis, Hannover
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Planning capacities when regenerating complex investment goods involves particular challenges in that the planning is subject to a large degree of uncertainty regarding load information. Using information fusion – by applying Bayesian Networks – a method is being developed for forecasting the anticipated expenditures (human labor, tool and machinery utilization, time etc.) for regenerating a good. The generated forecasts then later serve as a tool for planning capacities and ensure a greater stability in the planning processes.
Keywords: Bayesian networks, capacity planning, complex investment goods, damages library, forecasting, information fusion, regeneration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1631566 Symbolic Analysis of Large Circuits Using Discrete Wavelet Transform
Authors: Ali Al-Ataby , Fawzi Al-Naima
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Symbolic Circuit Analysis (SCA) is a technique used to generate the symbolic expression of a network. It has become a well-established technique in circuit analysis and design. The symbolic expression of networks offers excellent way to perform frequency response analysis, sensitivity computation, stability measurements, performance optimization, and fault diagnosis. Many approaches have been proposed in the area of SCA offering different features and capabilities. Numerical Interpolation methods are very common in this context, especially by using the Fast Fourier Transform (FFT). The aim of this paper is to present a method for SCA that depends on the use of Wavelet Transform (WT) as a mathematical tool to generate the symbolic expression for large circuits with minimizing the analysis time by reducing the number of computations.Keywords: Numerical Interpolation, Sparse Matrices, SymbolicAnalysis, Wavelet Transform.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1551565 All-Optical Function Based on Self-Similar Spectral Broadening for 2R Regeneration in High-Bit-Rate Optical Transmission Systems
Authors: Leila Graini
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In this paper, we demonstrate basic all-optical functions for 2R regeneration (Re-amplification and Re-shaping) based on self-similar spectral broadening in low normal dispersion and highly nonlinear fiber (ND-HNLF) to regenerate the signal through optical filtering including the transfer function characteristics, and output extinction ratio. Our approach of all-optical 2R regeneration is based on those of Mamyshev. The numerical study reveals the self-similar spectral broadening very effective for 2R all-optical regeneration; the proposed design presents high stability compared to a conventional regenerator using SPM broadening with reduction of the intensity fluctuations and improvement of the extinction ratio.
Keywords: All-optical function, 2R optical regeneration, self-similar broadening, Mamyshev regenerator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 819564 Fuzzy PID based PSS Design Using Genetic Algorithm
Authors: Ermanu A. Hakim, Adi Soeprijanto, Mauridhi H.P
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This paper presents PSS (Power system stabilizer) design based on optimal fuzzy PID (OFPID). OFPID based PSS design is considered for single-machine power systems. The main motivation for this design is to stabilize or to control low-frequency oscillation on power systems. Firstly, describing the linear PID control then to combine this PID control with fuzzy logic control mechanism. Finally, Fuzzy PID parameters (Kp. Kd, KI, Kupd, Kui) are tuned by Genetic Algorthm (GA) to reach optimal global stability. The effectiveness of the proposed PSS in increasing the damping of system electromechanical oscillation is demonstrated in a one-machine-infinite-bus system
Keywords: Fuzzy PID, Genetic Algorithm, power system stabilizer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1748563 Dissipation of Higher Mode using Numerical Integration Algorithm in Dynamic Analysis
Authors: Jin Sup Kim, Woo Young Jung, Minho Kwon
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In general dynamic analyses, lower mode response is of interest, however the higher modes of spatially discretized equations generally do not represent the real behavior and not affects to global response much. Some implicit algorithms, therefore, are introduced to filter out the high-frequency modes using intended numerical error. The objective of this study is to introduce the P-method and PC α-method to compare that with dissipation method and Newmark method through the stability analysis and numerical example. PC α-method gives more accuracy than other methods because it based on the α-method inherits the superior properties of the implicit α-method. In finite element analysis, the PC α-method is more useful than other methods because it is the explicit scheme and it achieves the second order accuracy and numerical damping simultaneously.Keywords: Dynamic, α-Method, P-Method, PC α-Method, Newmark method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3076562 Self-evolving Neural Networks Based On PSO and JPSO Algorithms
Authors: Abdussamad Ismail, Dong-Sheng Jeng
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A self-evolution algorithm for optimizing neural networks using a combination of PSO and JPSO is proposed. The algorithm optimizes both the network topology and parameters simultaneously with the aim of achieving desired accuracy with less complicated networks. The performance of the proposed approach is compared with conventional back-propagation networks using several synthetic functions, with better results in the case of the former. The proposed algorithm is also implemented on slope stability problem to estimate the critical factor of safety. Based on the results obtained, the proposed self evolving network produced a better estimate of critical safety factor in comparison to conventional BPN network.
Keywords: Neural networks, Topology evolution, Particle swarm optimization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1807561 Numerical Treatment of Block Method for the Solution of Ordinary Differential Equations
Authors: A. M. Sagir
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Discrete linear multistep block method of uniform order for the solution of first order initial value problems (IVPs) in ordinary differential equations (ODEs) is presented in this paper. The approach of interpolation and collocation approximation are adopted in the derivation of the method which is then applied to first order ordinary differential equations with associated initial conditions. The continuous hybrid formulations enable us to differentiate and evaluate at some grids and off – grid points to obtain four discrete schemes, which were used in block form for parallel or sequential solutions of the problems. Furthermore, a stability analysis and efficiency of the block method are tested on ordinary differential equations, and the results obtained compared favorably with the exact solution.
Keywords: Block Method, First Order Ordinary Differential Equations, Hybrid, Self starting.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2794560 Robust Control of a High-Speed Manipulator in State Space
Authors: M. M. Fateh, A. Izadbakhsh
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A robust control approach is proposed for a high speed manipulator using a hybrid computed torque control approach in the state space. The high-speed manipulator is driven by permanent magnet dc motors to track a trajectory in the joint space in the presence of disturbances. Tracking problem is analyzed in the state space where the completed models are considered for actuators. The proposed control approach can guarantee the stability and a satisfactory tracking performance. A two-link elbow manipulator driven by electrical actuators is simulated and results are shown to satisfy conditions under technical specifications.
Keywords: Computed torque, manipulator, robust control, state space.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2339559 Comparative Study of Ad Hoc Routing Protocols in Vehicular Ad-Hoc Networks for Smart City
Authors: Khadija Raissi, Bechir Ben Gouissem
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In this paper, we perform the investigation of some routing protocols in Vehicular Ad-Hoc Network (VANET) context. Indeed, we study the efficiency of protocols like Dynamic Source Routing (DSR), Ad hoc On-demand Distance Vector Routing (AODV), Destination Sequenced Distance Vector (DSDV), Optimized Link State Routing convention (OLSR) and Vehicular Multi-hop algorithm for Stable Clustering (VMASC) in terms of packet delivery ratio (PDR) and throughput. The performance evaluation and comparison between the studied protocols shows that the VMASC is the best protocols regarding fast data transmission and link stability in VANETs. The validation of all results is done by the NS3 simulator.
Keywords: VANET, smart city, AODV, OLSR, DSR, OLSR, VMASC, routing protocols, NS3.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1027558 Impact Analysis Based on Change Requirement Traceability in Object Oriented Software Systems
Authors: Sunil Tumkur Dakshinamurthy, Mamootil Zachariah Kurian
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Change requirement traceability in object oriented software systems is one of the challenging areas in research. We know that the traces between links of different artifacts are to be automated or semi-automated in the software development life cycle (SDLC). The aim of this paper is discussing and implementing aspects of dynamically linking the artifacts such as requirements, high level design, code and test cases through the Extensible Markup Language (XML) or by dynamically generating Object Oriented (OO) metrics. Also, non-functional requirements (NFR) aspects such as stability, completeness, clarity, validity, feasibility and precision are discussed. We discuss this as a Fifth Taxonomy, which is a system vulnerability concern.
Keywords: Artifacts, NFRs, OO metrics, SDLC, XML.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1156557 Bactericidal Properties of Carbohydrate-Stabilized Platinum Oxide Nanoparticles
Authors: Saeed Rezaei-Zarchi
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Platinum oxide nanoparticles were prepared by a simple hydrothermal route and chemical reduction using carbohydrates (Fructose and sucrose) as the reducing and stabilizing agents. The crystallite size of these nanoparticles was evaluated from X-ray diffraction (XRD), atomic force microscopy (AFM) and transmission electron microscopy (TEM) and was found to be 10 nm as shown in figure 1, which is the demonstration of EM bright field and transmission electron microscopy. The effect of carbohydrates on the morphology of the nanoparticles was studied using TEM (Figure 1). The nanoparticles (100 μg/ml) were administered to the Pseudomonas Stutzeri and Lactobacillus cultures and the incubation was done at 35 oC for 24 hours. The nanocomposites exhibited interesting inhibitory as well as bactericidal activity against P. Stutzeri and and Lactobacillus species. Incorporation of nanoparticles also increased the thermal stability of the carbohydrates.Keywords: Platinum oxide, P. Stutzeri, Lactobacillus, bactericidal effect.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2114556 Stability of Square Plate with Concentric Cutout
Authors: B. S. Jayashankarbabu, Karisiddappa
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The finite element method is used to obtain the elastic buckling load factor for square isotropic plate containing circular, square and rectangular cutouts. ANSYS commercial finite element software had been used in the study. The applied inplane loads considered are uniaxial and biaxial compressions. In all the cases the load is distributed uniformly along the plate outer edges. The effects of the size and shape of concentric cutouts with different plate thickness ratios and the influence of plate edge conditions, such as SSSS, CCCC and mixed boundary condition SCSC on the plate buckling strength have been considered in the analysis.
Keywords: Concentric cutout, Elastic buckling, Finite element method, Inplane loads, Thickness ratio.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3226555 The Effect of Lime Stabilization on E. coli Destruction and Heavy Metal Bioavailability in Sewage Sludge for Agricultural Utilization
Authors: G. Petruzzelli, F. Pedron, M. Grifoni, A. Pera, I. Rosellini, B. Pezzarossa
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The addition of lime as Ca(OH)2 to sewage sludge to destroy pathogens (Escherichia coli), was evaluated also in relation to heavy metal bioavailability. The obtained results show that the use of calcium hydroxide at the dose of 3% effectively destroyed pathogens ensuring the stability at high pH values over long period and the duration of the sewage sludge stabilization. In general, lime addition decreased the total extractability of heavy metals indicating a reduced bioavailability of these elements. This is particularly important for a safe utilization in agricultural soils to reduce the possible transfer of heavy metals to the food chain.Keywords: Biological sludge, Ca(OH)2, copper, pathogens, sanitation, zinc.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2654554 Effect of Groove Location on the Dynamic Characteristics of Multiple Axial Groove Water Lubricated Journal Bearing
Authors: M. Vijaya Kini, R. S. Pai, D. Srikanth Rao, Satish Shenoy B, R. Pai
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The stability characteristics of water lubricated journal bearings having three axial grooves are obtained theoretically. In this lubricant (water) is fed under pressure from one end of the bearing, through the 3-axial grooves (groove angles may vary). These bearings can use the process fluid as the lubricant, as in the case of feed water pumps. The Reynolds equation is solved numerically by the finite difference method satisfying the boundary conditions. The stiffness and damping coefficient for various bearing number and eccentricity ratios, assuming linear pressure drop along the groove, shows that smaller groove angles better results.
Keywords: 3-axial groove, dynamic characteristics, groovelocation, water lubricated bearings.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2131553 Appraisal on Link Lifetime Prediction Using Geographical Information
Authors: C. Nallusamy, A. Sabari, K. Suganya
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Geographical routing protocol requires node physical location information to make forwarding decision. Geographical routing uses location service or position service to obtain the position of a node. The geographical information is a geographic coordinates or can be obtained through reference points on some fixed coordinate system. Link can be formed between two nodes. Link lifetime plays a crucial role in MANET. Link lifetime represent how long the link is stable without any failure between the nodes. Link failure may occur due to mobility and because of link failure energy of nodes can be drained. Thus this paper proposes survey about link lifetime prediction using geographical information.Keywords: MANET, Geographical routing, Link lifetime, Link stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1726552 A Numerical Method for Diffusion and Cahn-Hilliard Equations on Evolving Spherical Surfaces
Authors: Jyh-Yang Wu, Sheng-Gwo Chen
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In this paper, we present a simple effective numerical geometric method to estimate the divergence of a vector field over a curved surface. The conservation law is an important principle in physics and mathematics. However, many well-known numerical methods for solving diffusion equations do not obey conservation laws. Our presented method in this paper combines the divergence theorem with a generalized finite difference method and obeys the conservation law on discrete closed surfaces. We use the similar method to solve the Cahn-Hilliard equations on evolving spherical surfaces and observe stability results in our numerical simulations.Keywords: Conservation laws, diffusion equations, Cahn-Hilliard Equations, evolving surfaces.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1504