Search results for: Thermal Stability.
1042 Multivariable Predictive PID Control for Quadruple Tank
Authors: Qamar Saeed, Vali Uddin, Reza Katebi
Abstract:
In this paper multivariable predictive PID controller has been implemented on a multi-inputs multi-outputs control problem i.e., quadruple tank system, in comparison with a simple multiloop PI controller. One of the salient feature of this system is an adjustable transmission zero which can be adjust to operate in both minimum and non-minimum phase configuration, through the flow distribution to upper and lower tanks in quadruple tank system. Stability and performance analysis has also been carried out for this highly interactive two input two output system, both in minimum and non-minimum phases. Simulations of control system revealed that better performance are obtained in predictive PID design.Keywords: Proportional-integral-derivative Control, GeneralizedPredictive Control, Predictive PID Control, Multivariable Systems
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32761041 On the Modeling and State Estimation for Dynamic Power System
Authors: A. Thabet, M. Boutayeb, M. N. Abdelkrim
Abstract:
This paper investigates a method for the state estimation of nonlinear systems described by a class of differential-algebraic equation (DAE) models using the extended Kalman filter. The method involves the use of a transformation from a DAE to ordinary differential equation (ODE). A relevant dynamic power system model using decoupled techniques will be proposed. The estimation technique consists of a state estimator based on the EKF technique as well as the local stability analysis. High performances are illustrated through a simulation study applied on IEEE 13 buses test system.
Keywords: Power system, Dynamic decoupled model, Extended Kalman Filter, Convergence analysis, Time computing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27371040 Numerical Analysis for the Performance of a Thermoelectric Generator According to Engine Exhaust Gas Thermal Conditions
Authors: Jinkyu Park, Yungjin Kim, Byungdeok In, Sangki Park, Kihyung Lee
Abstract:
Internal combustion engines rejects 30-40% of the energy supplied by fuel to the environment through exhaust gas. thus, there is a possibility for further significant improvement of efficiency with the utilization of exhaust gas energy and its conversion to mechanical energy or electrical energy. The Thermo-Electric Generator (TEG) will be located in the exhaust system and will make use of an energy flow between the warmer exhaust gas and the external environment. Predict to th optimum position of temperature distribution and the performance of TEG through numerical analysis. The experimental results obtained show that the power output significantly increases with the temperature difference between cold and hot sides of a thermoelectric generator.Keywords: Thermoelectric generator, Numerical analysis, Seebeck coefficient, Figure of merit
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22691039 Structural Safety Evaluation of Zip-Line Due to Dynamic Impact Load
Authors: Bu Seog Ju, Jae Sang Kim, Woo Young Jung
Abstract:
In recent year, with recent increase of interest towards leisure sports, increased number of Zip-Line or Zip-Wire facilities has built. Many researches have been actively conducted on the emphasis of the cable and the wire at the bridge. However, very limited researches have been conducted on the safety of the Zip-Line structure. In fact, fall accidents from Zip-Line have been reported frequently. Therefore, in this study, the structural safety of Zip-Line under dynamic impact loading condition were evaluated on the previously installed steel cable for leisure (Zip-Line), using 3-dimensional nonlinear Finite Element (FE) model. The result from current study would assist assurance of systematic stability of Zip-Line.
Keywords: Zip-Line, Wire, Cable, 3D FE Model, Safety.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 41041038 The Exploitation of Balancing an Inverted Pendulum System Using Sliding Mode Control
Authors: Sheren H. Salah, Ahmed Y. Ben Sasi
Abstract:
The inverted pendulum system is a classic control problem that is used in universities around the world. It is a suitable process to test prototype controllers due to its high non-linearities and lack of stability. The inverted pendulum represents a challenging control problem, which continually moves toward an uncontrolled state. This paper presents the possibility of balancing an inverted pendulum system using sliding mode control (SMC). The goal is to determine which control strategy delivers better performance with respect to pendulum’s angle and cart's position. Therefore, proportional-integral-derivative (PID) is used for comparison. Results have proven SMC control produced better response compared to PID control in both normal and noisy systems.Keywords: Inverted pendulum (IP) proportional-integralderivative (PID), sliding mode control (SMC).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20601037 Study of Effect Different of Ozone Doses on Sugars Content in Tomatoes at Different Stages of Ripening
Authors: Milad. A. Shalluf
Abstract:
The determination of sugars in foods is very significant. Their relation in fact, can affect the chemical and sensorial quality of the matrix (e.g., sweetness, pH, total acidity, microbial stability, global acceptability) and can provide information on food to optimize several selected technological processes. Three stages of ripeness (green, yellow and red) of tomatoes (Lycopersicon Esculentum cv. Elegance) at different harvest dates were evaluated. Fruit from all harvests were exposed to different of ozone doses (0.25, 0.50 and 1 mg O3/g tomatoes) and clean air for 5 day at 15 °C±2 and 90-95 % relative humidity. Then, fruits were submitted for extraction and analysis after a day from the finish of exposure of each stage. The concentrations of the glucose and fructose increased in the tomatoes which were subjected to ozone treatments.Keywords: Post-harvest Treatment, Controlled Atmosphere Storage, Ozone, Tomatoes, Glucose, Fructose
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19301036 Conceptual Design of Aeroelastic Demonstrator for Whirl Flutter Simulation
Authors: J. Cecrdle, J. Malecek
Abstract:
This paper deals with the conceptual design of the new aeroelastic demonstrator for the whirl flutter simulation. The paper gives a theoretical background of the whirl flutter phenomenon and describes the events of the whirl flutter occurrence in the aerospace practice. The second part is focused on the experimental research of the whirl flutter on aeroelastic similar models. Finally the concept of the new aeroelastic demonstrator is described. The demonstrator represents the wing and engine of the twin turboprop commuter aircraft including a driven propeller. It allows the changes of the main structural parameters influencing the whirl flutter stability characteristics. It is intended for the experimental investigation of the whirl flutter in the wind tunnel. The results will be utilized for validation of analytical methods and software tools.Keywords: aeroelasticity, flutter, whirl flutter, W-WING demonstrator
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30951035 Atoms in Molecules, An Other Method For Analyzing Dibenzoylmethane
Authors: S. Heydarian
Abstract:
Proton transfer and hydrogen bonding are two aspects of the chemistry of hydrogen that respectively govern the behaviour and structure of many molecules, both simple and complex. All the theoretical enol and keto conformations of 1,3-diphenyl-1,3- propandion known as dibenzoylmethane (DBM), have been investigated by means of atoms in molecules (AIM) theory. It was found that the most stable conformers are those stabilized by hydrogen bridges.The aim of the present paper is a thorough conformational analysis of DBM (with special attention on chelated cis-enol conformers) in order to obtain detailed information on the geometrical parameters, relative stabilities and rotational motion of the phenyl groups. It is also important to estimate the barrier height for ptoton transfer and hydrogen bond strength, which are the main factors governing conformational stability.Keywords: Acetylacetone, Atoms in molecules, Dibenzoylmethane, Intramolecular hydrogen bond, Resonanceconjugation
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17611034 Sliding Mode Control Based on Backstepping Approach for an UAV Type-Quadrotor
Authors: H. Bouadi, M. Bouchoucha, M. Tadjine
Abstract:
In this paper; we are interested principally in dynamic modelling of quadrotor while taking into account the high-order nonholonomic constraints in order to develop a new control scheme as well as the various physical phenomena, which can influence the dynamics of a flying structure. These permit us to introduce a new state-space representation. After, the use of Backstepping approach for the synthesis of tracking errors and Lyapunov functions, a sliding mode controller is developed in order to ensure Lyapunov stability, the handling of all system nonlinearities and desired tracking trajectories. Finally simulation results are also provided in order to illustrate the performances of the proposed controller.
Keywords: Dynamic modeling, nonholonomic constraints, Backstepping, sliding mode.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 58801033 Design of Saddle Support for Horizontal Pressure Vessel
Authors: Vinod Kumar, Navin Kumar, Surjit Angra, Prince Sharma
Abstract:
This paper presents the design analysis of saddle support of a horizontal pressure vessel. Since saddle have the vital role to support the pressure vessel and to maintain its stability, it should be designed in such a way that it can afford the vessel load and internal pressure of the vessel due to liquid contained in the vessel. A model of horizontal pressure vessel and saddle support is created in ANSYS. Stresses are calculated using mathematical approach and ANSYS software. The analysis reveals the zone of high localized stress at the junction part of the pressure vessel and saddle support due to operating conditions. The results obtained by both the methods are compared with allowable stress value for safe designing.
Keywords: ANSYS, Pressure Vessel, Saddle, Support.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 261441032 A Comparative Study on Air Permeability Properties of Multilayered Nonwoven Structures
Authors: M. Kucukali Ozturk, B. Nergis, C. Candan
Abstract:
Air permeability plays an important role for applications such as filtration, thermal and acoustic insulation. The study discussed in this paper was conducted in an attempt to investigate air permeability property of various combinations of nonwovens. The PROWHITE air permeability tester was used for the measurement of the air permeability of the samples in accordance with the relevant standards and a comparative study of the results were made. It was found that the fabric mass per unit area was closely related to the air-permeability. The air permeability decreased with the increase in mass per unit area. Additionally, the air permeability of nonwoven fabrics decreased with the increase in thickness. Moreover, air permeability of multilayered SMS nonwoven structures was lower than those of single layered ones.
Keywords: Air permeability, mass per unit area, nonwoven structure, polypropylene nonwoven, thickness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16601031 Changes in the Properties of Composites Caused by Chemical Treatment of Hemp Hurds
Authors: N. Stevulova, I. Schwarzova
Abstract:
The possibility of using industrial hemp as a source of natural fibers for purpose of construction, mainly for the preparation of lightweight composites based on hemp hurds is described. In this article, an overview of measurement results of important technical parameters (compressive strength, density, thermal conductivity) of composites based on organic filler - chemically modified hemp hurds in three solutions (EDTA, NaOH and Ca(OH)2) and inorganic binder MgO-cement after 7, 28, 60, 90 and 180 days of hardening is given. The results of long-term water storage of 28 days hardened composites at room temperature were investigated. Changes in the properties of composites caused by chemical treatment of hemp material are discussed.
Keywords: Hemp hurds, chemical modification, lightweight composites, testing material properties.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22671030 Entropy Generation for Natural Convection in a Darcy – Brinkman Porous Cavity
Authors: Ali Mchirgui, Nejib Hidouri, Mourad Magherbi, Ammar Ben Brahim
Abstract:
The paper provides a numerical investigation of the entropy generation analysis due to natural convection in an inclined square porous cavity. The coupled equations of mass, momentum, energy and species conservation are solved using the Control Volume Finite-Element Method. Effect of medium permeability and inclination angle on entropy generation is analysed. It was found that according to the Darcy number and the porous thermal Raleigh number values, the entropy generation could be mainly due to heat transfer or to fluid friction irreversibility and that entropy generation reaches extremum values for specific inclination angles.Keywords: Porous media, entropy generation, convection, numerical method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26071029 Bioclimatic Principles and Urban Open Spaces: The Case of Xanthi
Authors: Maria Giannopoulou
Abstract:
Open urban public spaces comprise an important element for the development of social, cultural and economic activities of the population in the modern cities. These spaces are also considered regulators of the region-s climate conditions, providing better thermal, visual and auditory conditions which can be optimized by the application of appropriate strategies of bioclimatic design. The paper focuses on the analysis and evaluation of the recent unification of the open spaces in the centre of Xanthi, a medium – size city in northern Greece, from a bioclimatic perspective, as well as in the creation of suitable methodology. It is based both on qualitative observation of the interventions by fieldwork research and assessment and on quantitative analysis and modeling of the research area.Keywords: Bioclimatic principles, Quantitative analysis, Sustainability, TownScope III, Urban open spaces
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27911028 Synthesis of Temperature Sensitive Nano/Microgels by Soap-Free Emulsion Polymerization and Their Application in Hydrate Sediments Drilling Operations
Authors: Xuan Li, Weian Huang, Jinsheng Sun, Fuhao Zhao, Zhiyuan Wang, Jintang Wang
Abstract:
Natural gas hydrates (NGHs) as promising alternative energy sources have gained increasing attention. Hydrate-bearing formation in marine areas is highly unconsolidated formation and is fragile, which is composed of weakly cemented sand-clay and silty sediments. During the drilling process, the invasion of drilling fluid can easily lead to excessive water content in the formation. It will change the soil liquid plastic limit index, which significantly affects the formation quality, leading to wellbore instability due to the metastable character of hydrate-bearing sediments. Therefore, controlling the filtrate loss into the formation in the drilling process has to be highly regarded for protecting the stability of the wellbore. In this study, the temperature-sensitive nanogel of P(NIPAM-co-AMPS-co-tBA) was prepared by soap-free emulsion polymerization, and the temperature-sensitive behavior was employed to achieve self-adaptive plugging in hydrate sediments. First, the effects of additional amounts of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS), tert-butyl acrylate (tBA), and methylene-bis-acrylamide (MBA) on the microgel synthesis process and temperature-sensitive behaviors were investigated. Results showed that, as a reactive emulsifier, AMPS can not only participate in the polymerization reaction but also act as an emulsifier to stabilize micelles and enhance the stability of nanoparticles. The volume phase transition temperature (VPTT) of nanogels gradually decreased with the increase of the contents of hydrophobic monomer tBA. An increase in the content of the cross-linking agent MBA can lead to a rise in the coagulum content and instability of the emulsion. The plugging performance of nanogel was evaluated in a core sample with a pore size distribution range of 100-1000 nm. The temperature-sensitive nanogel can effectively improve the microfiltration performance of drilling fluid. Since a combination of a series of nanogels could have a wide particle size distribution at any temperature, around 200 nm to 800 nm, the self-adaptive plugging capacity of nanogels for the hydrate sediments was revealed. Thermosensitive nanogel is a potential intelligent plugging material for drilling operations in NGH-bearing sediments.
Keywords: Temperature-sensitive nanogel, NIPAM, self-adaptive plugging performance, drilling operations, hydrate-bearing sediments.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1311027 The Effect of the Crystal Field Interaction on the Critical Temperatures and the Sublattice Magnetizations of a Mixed Spin-3/2 and Spin-5/2 Ferrimagnetic System
Authors: Fathi Abubrig, Mohamed Delfag, Suad M. Abuzariba
Abstract:
The influence of the crystal field interactions on the mixed spin-3/2 and spin-5/2 ferrimagnetic Ising system is considered by using the mean field theory based on Bogoliubov inequality for the Gibbs free energy. The ground-state phase diagram is constructed, the phase diagrams of the second-order critical temperatures are obtained, and the thermal variation of the sublattice magnetizations is investigated in detail. We find some interesting phenomena for the sublattice magnetizations at particular values of the crystal field interactions.
Keywords: Crystal field, Ising system, Ferrimagnetic, magnetization, phase diagrams.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21401026 Design and Implementation of an Intelligent System for Detection of Hazardous Gases using PbPc Sensor Array
Authors: Mahmoud Z. Iskandarani, Nidal F. Shilbayeh
Abstract:
The voltage/current characteristics and the effect of NO2 gas on the electrical conductivity of a PbPc gas sensor array is investigated. The gas sensor is manufactured using vacuum deposition of gold electrodes on sapphire substrate with the leadphathalocyanine vacuum sublimed on the top of the gold electrodes. Two versions of the PbPc gas sensor array are investigated. The tested types differ in the gap sizes between the deposited gold electrodes. The sensors are tested at different temperatures to account for conductivity changes as the molecular adsorption/desorption rate is affected by heat. The obtained results found to be encouraging as the sensors shoed stability and sensitivity towards low concentration of applied NO2 gas.Keywords: Intelligent System, PbPc, Gas Sensor, Hardware, Software, Neural.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15751025 Investigation of Stability of Functionally Graded Material when Encountering Periodic Loading
Authors: M. Amiri
Abstract:
In this work, functionally graded materials (FGMs), subjected to loading, which varies with time has been studied. The material properties of FGM are changing through the thickness of material as power law distribution. The conical shells have been chosen for this study so in the first step capability equations for FGM have been obtained. With Galerkin method, these equations have been replaced with time dependant differential equations with variable coefficient. These equations have solved for different initial conditions with variation methods. Important parameters in loading conditions are semi-vertex angle, external pressure and material properties. Results validation has been done by comparison between with those in previous studies of other researchers.
Keywords: Impulsive semi-vertex angle, loading, functionally graded materials, composite material.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12031024 Assessing the Effect of Thermodynamic, Hydrodynamic and Geometric of an Air Cooled Condenser on COP of Vapor Compression Cycle
Authors: Hosein Shokohmand, Mahmood Hosein Zare, Abdorreza Qolibeik
Abstract:
In this paper, the effects of thermodynamic, hydrodynamic and geometric of an air cooled condenser on COP of vapor compression cycle are investigated for a fixed condenser facing surface area. The system is utilized with a scroll compressor, modeled based on thermodynamic and heat transfer equations employing Matlab software. The working refrigerant is R134a whose thermodynamic properties are called from Engineering Equation Software. This simulation shows that vapor compression cycle can be designed by different configurations and COPs, economical and optimum working condition can be obtained via considering these parameters.Keywords: Vapor compression cycle, air cooled condenser, COP, heat exchanger, thermal modeling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19641023 Feasibility of Leukemia Cancer Treatment (K562) by Atmospheric Pressure Plasma Jet
Authors: Mashayekh Amir Shahriar, Akhlaghi Morteza, Rajaee Hajar, Khani Mohammad Reza, Shokri Babak
Abstract:
A new and novel approach in medicine is the use of cold plasma for various applications such as sterilization blood coagulation and cancer cell treatment. In this paper a pin-to-hole plasma jet suitable for biological applications is investigated and characterized and the possibility and feasibility of cancer cell treatment is evaluated. The characterization includes power consumption via Lissajous method, thermal behavior of plasma using Infra-red camera as a novel method, Optical Emission Spectroscopy (OES) to determine the species that are generated. Treatment of leukemia cancer cells is also implemented and MTT assay is used to evaluate viability.
Keywords: Atmospheric Pressure Plasma Jet (APPJ), Plasma Medicine, Cancer cell treatment, leukemia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22351022 A Servo Control System Using the Loop Shaping Design Procedure
Authors: Naohiro Ban, Hiromitsu Ogawa, Manato Ono, Yoshihisa Ishida
Abstract:
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 24111021 Bifurcation Method for Solving Positive Solutions to a Class of Semilinear Elliptic Equations and Stability Analysis of Solutions
Authors: Hailong Zhu, Zhaoxiang Li
Abstract:
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 16481020 Choice of Exchange Rate Regimes: Case of Ex-Yugoslavia Countries
Authors: Ivan Lovrinović, Gordana Kordić, Martina Nakić
Abstract:
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 19541019 A Tubular Electrode for Radiofrequency Ablation Therapy
Authors: Carlos L. Antunes, Tony R. Almeida, Nélia Raposeiro, Belarmino Gonçalves, Paulo Almeida, André Antunes
Abstract:
In the last two decades radiofrequency ablation (RFA) has been considered a promising medical procedure for the treatment of primary and secondary malignancies. However, the needle-based electrodes so far developed for this kind of treatment are not suitable for the thermal ablation of tumors located in hollow organs like esophagus, colon or bile duct. In this work a tubular electrode solution is presented. Numerical and experimental analyses were performed to characterize the volume of the lesion induced. Results show that this kind of electrode is a feasible solution and numerical simulation might provide a tool for planning RFA procedure with some accuracy.Keywords: 3D modeling, cancer, medical therapy, radiofrequency ablation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18741018 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
Abstract:
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 11981017 CFD Simulations to Study the Cooling Effects of Different Greening Modifications
Authors: An-Shik Yang, Chih-Yung Wen, Chiang-Ho Cheng, Yu-Hsuan Juan
Abstract:
The objective of this study is to conduct computational fluid dynamic (CFD) simulations for evaluating the cooling efficacy from vegetation implanted in a public park in the Taipei, Taiwan. To probe the impacts of park renewal by means of adding three pavilions and supplementary green areas on urban microclimates, the simulated results have revealed that the park having a higher percentage of green coverage ratio (GCR) tended to experience a better cooling effect. These findings can be used to explore the effects of different greening modifications on urban environments for achieving an effective thermal comfort in urban public spaces.Keywords: CFD simulations, green coverage ratio, urban heat island, urban public park.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28311016 Sustainable Production of Oyster Mushroom (Pleurotus ostreatus) in Chiapas, Mexico
Authors: Sandoval Villa Héctor, Estrada Velazco Evaristo, Chavarría Alamilla Luis
Abstract:
Pleurotus ostreatus is a common edible mushroom with a number of properties that can help to solve the nutritional and economical problems of people in Chiapas, Mexico. The objective of this project was to produce the mushroom under a sustainable management in which only regional products were allowed as a way to promote the cultivation and consumption of Pleurotus ostreatus; 5 different substrates were tested as well as 2 sanitation methods. The obtained results showed that the highest yields were obtained using corn husk and a thermal sanitation method. Pests and diseases were not a problem during the project but they appeared more in the substrates sanitized with calcium hydroxide.
Keywords: Pleurotus ostreatus, substrates, sanitation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32391015 Energy-Efficient Sensing Concept for a Micromachined Yaw Rate Sensor
Authors: D. Oshinubi, M. Rocznik, K. Dostert
Abstract:
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 15061014 Project and Module Based Teaching and Learning
Authors: Jingyu Hou
Abstract:
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 34531013 Immobilization of Simulated High Level Nuclear Wastes with Li2O-CeO2-Fe2O3-P2O5 Glasses
Authors: Toshinori Okura, Naoya Yoshida
Abstract:
The leaching behavior and structure of Li2O-CeO2- Fe2O3-P2O5 glasses incorporated with simulated high level nuclear wastes (HLW) were studied. The leach rates of gross and each constituent element were determined from the total weight loss of the specimen and the leachate analyses by inductively coupled argon plasma spectroscopy (ICP). The gross leach rate of the 4.5Li2O- 9.7CeO2-34.7Fe2O3-51.5P2O5 glass waste form containing 45 mass% simulated HLW is of the order of 10
Keywords: FT-IR spectra, Leach rates, Li2O-CeO2-Fe2O3-P2O5 glasses, Nuclear waste immobilization, Thermal properties
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2084