Search results for: Linear/nonlinear plants
1326 Calculation of the Thermal Stresses in an Elastoplastic Plate Heated by Local Heat Source
Authors: M. Khaing, A. V. Tkacheva
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The work is devoted to solving the problem of temperature stresses, caused by the heating point of the round plate. The plate is made of elastoplastic material, so the Prandtl-Reis model is used. A piecewise-linear condition of the Ishlinsky-Ivlev flow is taken as the loading surface, in which the yield stress depends on the temperature. Piecewise-linear conditions (Treska or Ishlinsky-Ivlev), in contrast to the Mises condition, make it possible to obtain solutions of the equilibrium equation in an analytical form. In the problem under consideration, using the conditions of Tresca, it is impossible to obtain a solution. This is due to the fact that the equation of equilibrium ceases to be satisfied when the two Tresca conditions are fulfilled at once. Using the conditions of plastic flow Ishlinsky-Ivlev allows one to solve the problem. At the same time, there are also no solutions on the edge of the Ishlinsky-Ivlev hexagon in the plane-stressed state. Therefore, the authors of the article propose to jump from the edge to the edge of the mine edge, which gives an opportunity to obtain an analytical solution. At the same time, there is also no solution on the edge of the Ishlinsky-Ivlev hexagon in a plane stressed state; therefore, in this paper, the authors of the article propose to jump from the side to the side of the mine edge, which gives an opportunity to receive an analytical solution. The paper compares solutions of the problem of plate thermal deformation. One of the solutions was obtained under the condition that the elastic moduli (Young's modulus, Poisson's ratio) which depend on temperature. The yield point is assumed to be parabolically temperature dependent. The main results of the comparisons are that the region of irreversible deformation is larger in the calculations obtained for solving the problem with constant elastic moduli. There is no repeated plastic flow in the solution of the problem with elastic moduli depending on temperature. The absolute value of the irreversible deformations is higher for the solution of the problem in which the elastic moduli are constant; there are also insignificant differences in the distribution of the residual stresses.Keywords: Temperature stresses, elasticity, plasticity, Ishlinsky-Ivlev condition, plate, annular heating, elastic moduli.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7281325 Energy Analysis of Pressurized Solid Oxide Fuel Cell Combined Power Turbine
Authors: M. Ayazi, R. Karami, B. Kamkari
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Solid oxide fuel cells have been considered in the last years as one of the most promising technologies for very highefficiency electric energy generation from hydrogen or other hydrocarbons, both with simple fuel cell plants and with integrated gas turbine-fuel cell systems. In the present study, a detailed thermodynamic analysis has been carried out. Mass and exergy balances are performed not only for the whole plant but also for each component in order to evaluate the thermal efficiency of combined cycle. Moreover, different sources of irreversibilities within the SOFC stack have been discussed and a parametric study conducted to evaluate the effect of temperature as well as pressure on SOFC irreversibilities and its performance. In this investigation methane and hydrogen have been used for fueling the SOFC stack and combustion chamber.
Keywords: SOFC, Energy, Power turbine, Irreversibility.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18121324 Fatigue Analysis of Spread Mooring Line
Authors: Chanhoe Kang, Changhyun Lee, Seock-Hee Jun, Yeong-Tae Oh
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Offshore floating structure under the various environmental conditions maintains a fixed position by mooring system. Environmental conditions, vessel motions and mooring loads are applied to mooring lines as the dynamic tension. Because global responses of mooring system in deep water are specified as wave frequency and low frequency response, they should be calculated from the time-domain analysis due to non-linear dynamic characteristics. To take into account all mooring loads, environmental conditions, added mass and damping terms at each time step, a lot of computation time and capacities are required. Thus, under the premise that reliable fatigue damage could be derived through reasonable analysis method, it is necessary to reduce the analysis cases through the sensitivity studies and appropriate assumptions. In this paper, effects in fatigue are studied for spread mooring system connected with oil FPSO which is positioned in deep water of West Africa offshore. The target FPSO with two Mbbls storage has 16 spread mooring lines (4 bundles x 4 lines). The various sensitivity studies are performed for environmental loads, type of responses, vessel offsets, mooring position, loading conditions and riser behavior. Each parameter applied to the sensitivity studies is investigated from the effects of fatigue damage through fatigue analysis. Based on the sensitivity studies, the following results are presented: Wave loads are more dominant in terms of fatigue than other environment conditions. Wave frequency response causes the higher fatigue damage than low frequency response. The larger vessel offset increases the mean tension and so it results in the increased fatigue damage. The external line of each bundle shows the highest fatigue damage by the governed vessel pitch motion due to swell wave conditions. Among three kinds of loading conditions, ballast condition has the highest fatigue damage due to higher tension. The riser damping occurred by riser behavior tends to reduce the fatigue damage. The various analysis results obtained from these sensitivity studies can be used for a simplified fatigue analysis of spread mooring line as the reference.
Keywords: Mooring system, fatigue analysis, time domain, non-linear dynamic characteristics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25601323 Sway Reduction on Gantry Crane System using Delayed Feedback Signal and PD-type Fuzzy Logic Controller: A Comparative Assessment
Authors: M.A. Ahmad
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This paper presents the use of anti-sway angle control approaches for a two-dimensional gantry crane with disturbances effect in the dynamic system. Delayed feedback signal (DFS) and proportional-derivative (PD)-type fuzzy logic controller are the techniques used in this investigation to actively control the sway angle of the rope of gantry crane system. A nonlinear overhead gantry crane system is considered and the dynamic model of the system is derived using the Euler-Lagrange formulation. A complete analysis of simulation results for each technique is presented in time domain and frequency domain respectively. Performances of both controllers are examined in terms of sway angle suppression and disturbances cancellation. Finally, a comparative assessment of the impact of each controller on the system performance is presented and discussed.Keywords: Gantry crane, anti-sway control, DFS controller, PD-type Fuzzy Logic Controller.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21511322 Humic Acid and Azadirachtin Derivatives for the Management of Crop Pests
Authors: R. S. Giraddi, C. M. Poleshi
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Organic cultivation of crops is gaining importance consumer awareness towards pesticide residue free foodstuffs is increasing globally. This is also because of high costs of synthetic fertilizers and pesticides, making the conventional farming non-remunerative. In India, organic manures (such as vermicompost) are an important input in organic agriculture. Though vermicompost obtained through earthworm and microbe-mediated processes is known to comprise most of the crop nutrients, but they are in small amounts thus necessitating enrichment of nutrients so that crop nourishment is complete. Another characteristic of organic manures is that the pest infestations are kept under check due to induced resistance put up by the crop plants. In the present investigation, deoiled neem cake containing azadirachtin, copper ore tailings (COT), a source of micro-nutrients and microbial consortia were added for enrichment of vermicompost. Neem cake is a by-product obtained during the process of oil extraction from neem plant seeds. Three enriched vermicompost blends were prepared using vermicompost (at 70, 65 and 60%), deoiled neem cake (25, 30 and 35%), microbial consortia and COTwastes (5%). Enriched vermicompost was thoroughly mixed, moistened (25+5%), packed and incubated for 15 days at room temperature. In the crop response studies, the field trials on chili (Capsicum annum var. longum) and soybean, (Glycine max cv JS 335) were conducted during Kharif 2015 at the Main Agricultural Research Station, UAS, Dharwad-Karnataka, India. The vermicompost blend enriched with neem cake (known to possess higher amounts of nutrients) and vermicompost were applied to the crops and at two dosages and at two intervals of crop cycle (at sowing and 30 days after sowing) as per the treatment plan along with 50% recommended dose of fertilizer (RDF). 10 plants selected randomly in each plot were studied for pest density and plant damage. At maturity, crops were harvested, and the yields were recorded as per the treatments, and the data were analyzed using appropriate statistical tools and procedures. In the crops, chili and soybean, crop nourishment with neem enriched vermicompost reduced insect density and plant damage significantly compared to other treatments. These treatments registered as much yield (16.7 to 19.9 q/ha) as that realized in conventional chemical control (18.2 q/ha) in soybean, while 72 to 77 q/ha of green chili was harvested in the same treatments, being comparable to the chemical control (74 q/ha). The yield superiority of the treatments was of the order neem enriched vermicompost>conventional chemical control>neem cake>vermicompost>untreated control. The significant features of the result are that it reduces use of inorganic manures by 50% and synthetic chemical insecticides by 100%.
Keywords: Humic acid, azadirachtin, vermicompost, insect-pest.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8051321 Gain Tuning Fuzzy Controller for an Optical Disk Drive
Authors: Shiuh-Jer Huang, Ming-Tien Su
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Since the driving speed and control accuracy of commercial optical disk are increasing significantly, it needs an efficient controller to monitor the track seeking and following operations of the servo system for achieving the desired data extracting response. The nonlinear behaviors of the actuator and servo system of the optical disk drive will influence the laser spot positioning. Here, the model-free fuzzy control scheme is employed to design the track seeking servo controller for a d.c. motor driving optical disk drive system. In addition, the sliding model control strategy is introduced into the fuzzy control structure to construct a 1-D adaptive fuzzy rule intelligent controller for simplifying the implementation problem and improving the control performance. The experimental results show that the steady state error of the track seeking by using this fuzzy controller can maintain within the track width (1.6 μm ). It can be used in the track seeking and track following servo control operations.Keywords: Fuzzy control, gain tuning and optical disk drive.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15871320 Marangoni Convection in a Fluid Layer with Internal Heat Generation
Authors: Norfifah Bachok, Norihan Md. Arifin
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In this paper we use classical linear stability theory to investigate the effects of uniform internal heat generation on the onset of Marangoni convection in a horizontal layer of fluid heated from below. We use a analytical technique to obtain the close form analytical expression for the onset of Marangoni convection when the lower boundary is conducting with free-slip condition. We show that the effect of increasing the internal heat generation is always to destabilize the layer.Keywords: Marangoni convection, heat generation, free-slip
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17851319 Modeling the Moment of Resistance Generated by an Ore-Grinding Mill
Authors: Marinka Baghdasaryan, Tigran Mnoyan
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The pertinence of modeling the moment of resistance generated by the ore-grinding mill is substantiated. Based on the ranking of technological indices obtained in the result of the survey among the specialists of several beneficiating plants, the factors determining the level of the moment of resistance generated by the mill are revealed. A priori diagram of the ranks is obtained in which the factors are arranged in the descending order of the impact degree on the level of the moment. The obtained model of the moment of resistance shows the technological character of the operation modes of the ore-grinding mill and can be used for improving the operation modes of the system motor-mill and preventing the abnormal mode of the drive synchronous motor.Keywords: Model, abnormal mode, mill, correlation, moment of resistance, rotational speed.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9741318 Evaluation of Chlorophyll Content and Chlorophyll Fluorescence Parameters and Relationships between Chlorophyll a, b and Chlorophyll Content Index under Water Stress in Olea europaea cv. Dezful
Authors: E. Khaleghi, K. Arzani, N. Moallemi, M. Barzegar
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This study was conducted to determine effect of water stress on chlorophyll content and chlorophyll fluorescence parameter in young `Dezful- olive trees. Three irrigation regimes (40% ETcrop, 65% ETcrop and 100% ETcrop) were used. After irrigation treatments were applied, some of biochemical parameters including chlorophyll a, b, total chlorophyll, chlorophyll fluorescence and also chlorophyll content index (C.C.I) were measured. Results of Analysis of variance showed that irrigation treatments had significant effect on chlorophylla, total chlorophyll (chl a+b), C.C.I and Fv/Fm ratio. The amount of decreased chlorophyll a and total chlorophyll in plants were received 40% ETcrop were 51.55% and 46.86%, respectively, compared with 100% ETcrop.
Keywords: Evatarnspiration (ETcrop), Chlorophyll Content, Chlorophyll Fluorescence, Water stress, Olive
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 57641317 Numerical Investigation of Natural Convection of Pine, Olive, and Orange Leaves
Authors: Ali Reza Tahavvor, Saeed Hosseini, Nazli Jowkar, Behnam Amiri
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Heat transfer of leaves is a crucial factor in optimal operation of metabolic functions in plants. In order to quantify this phenomenon in different leaves and investigate the influence of leaf shape on heat transfer, natural convection for pine, orange and olive leaves was simulated as representatives of different groups of leaf shapes. CFD techniques were used in this simulation with the purpose to calculate heat transfer of leaves in similar environmental conditions. The problem was simulated for steady state and threedimensional conditions. From obtained results, it was concluded that heat fluxes of all three different leaves are almost identical, however, total rate of heat transfer have highest and lowest values for orange leaves, and pine leaves, respectively.Keywords: Computational fluid dynamic, heat flux, heat transfer, natural convection.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16601316 Environmental Issues Related to Nuclear Desalination
Authors: V. Anastasov, I.Khamis
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The paper presents an overview of environmental issues that may be expected with nuclear desalination. The analysis of coupling nuclear power with desalination plants indicates that adverse marine impacts can be mitigated with alternative intake designs or cooling systems. The atmospheric impact of desalination may be greatly reduced through the coupling with nuclear power, while maximizing the socio-economic benefit for both processes. The potential for tritium contamination of the desalinated water was reviewed. Experience with the systems and practices related to the radiological quality of the product water, shows no examples of cross-contamination. Furthermore, the indicators for the public acceptance of nuclear desalination, as one of the most important sustainability aspects of any such large project, show a positive trend. From the data collected, a conclusion is made that nuclear desalination should be supported by decision-makers.Keywords: Environmental impacts, nuclear desalination, publicacceptance, tritium.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26301315 Probabilistic Characteristics of older PR Frames in the Mid-America Earthquake Region
Authors: Do-Hwan Kim, Roberto Leon
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Probabilistic characteristics of seismic responses of the Partially Restrained connection rotation (PRCR) and panel zone deformation (PZD) installed in older steel moment frames were investigated in accordance with statistical inference in decision-making process. The 4, 6 and 8 story older steel moment frames with clip angle and T-stub connections were designed and analyzed using 2%/50yrs ground motions in four cities of the Mid-America earthquake region. The probability density function and cumulative distribution function of PRCR and PZD were determined by the goodness-of-fit tests based on probabilistic parameters measured from the results of the nonlinear time-history analyses. The obtained probabilistic parameters and distributions can be used to find out what performance level mainly PR connections and panel zones satisfy and how many PR connections and panel zones experience a serious damage under the Mid-America ground motions.Keywords: Mid-America earthquake, Panel zone, PR connection, Probabilistic characteristics, seismic performance
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14121314 The Factors Significant to Software Development Productivity
Authors: Zhizhong Jiang, Craig Comstock
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The past decade has seen enormous growth in the amount of software produced. However, given the ever increasing complexity of the software being developed and the concomitant rise in the typical project size, managers are becoming increasingly aware of the importance of issues that influence the productivity levels of the project teams involved. By analyzing the latest release of ISBSG data repository, we report on the factors found to significantly influence the productivity among which average team size and language type are the two most essential ones. Building on this we present an original model for evaluating the potential productivity during the project planning stage.Keywords: ISBSG, Linear Model, Productivity, SoftwareEngineering.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20801313 Design of Coal Quality Disturbance Free System for Coordinated Control System Based on Gain Scheduling
Authors: Liu Ji-Wei, Pei Yu-Liang, Liu Qian, Han Xiang, Zeng De-Liang
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The economic and stable operation was affected seriously by coal quality disturbance for power plants. Based on model analysis, influence of the disturbance can be considered as gain change of control system. Power capability coefficient of coal was constructed to inhibit it. Accuracy of the coefficient was verified by operating data. Then coal quality disturbance free system based on gain scheduling was designed for coordinated control system. Simulation showed that, the strategy improved control quality obviously, and inhibited the coal quality disturbance.Keywords: coordinate control system, coal quality disturbance, energy coefficient of coal quality, gain scheduling
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 14201312 Characterization of Catalagzi Fly Ash for Heavy Metal Adsorption
Authors: Nurcan Tugrul, Nil Baran Acarali, Seyma Kolemen, Emek Moroydor Derun, Sabriye Piskin
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Fly ash is a significant waste that is released of thermal power plants and defined as very fine particles that are drifted upward with up taken by the flue gases due to the burning of used coal [1]. The fly-ash is capable of removing organic contaminants in consequence of high carbon content, a large surface area per unit volume and contained heavy metals. Therefore, fly ash is used as an effective coagulant and adsorbent by pelletization [2, 3]. In this study, the possibility of use of fly ash taken from Turkey like low-cost adsorbent for adsorption of zinc ions found in waste water was investigated. The fly ash taken from Turkey was pelletized with bentonite and molass to evaluate the adsorption capaticity. For this purpose; analyses such as sieve analysis, XRD, XRF, FTIR and SEM were performed. As a result, it was seen that pellets prepared from fly ash, bentonite and molass would be used for zinc adsorption.Keywords: Fly ash, heavy metal, sieve, adsorbent.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25931311 Optimal Generation Expansion Planning Strategy with Carbon Trading
Authors: Tung-Sheng Zhan, Chih-Cheng Kao, Chin-Der Yang, Jong-Ian Tsai
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Fossil fuel-firing power plants dominate electric power generation in Taiwan, which are also the major contributor to Green House gases (GHG). CO2 is the most important greenhouse gas that cause global warming. This paper penetrates the relationship between carbon trading for GHG reduction and power generation expansion planning (GEP) problem for the electrical utility. The Particle Swarm Optimization (PSO) Algorithm is presented to deal with the generation expansion planning strategy of the utility with independent power providers (IPPs). The utility has to take both the IPPs- participation and environment impact into account when a new generation unit is considering expanded from view of supply side.Keywords: Carbon Trading, CO2 Emission, GenerationExpansion Planning (GEP), Green House gases (GHG), ParticleSwarm Optimization (PSO).
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16761310 Energy Efficient Recycling of in-Plant Fines
Authors: H. Ahmed, A. Persson, L. Sundqvist, B. Biorkman
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Numerous amounts of metallurgical dusts and sludge containing iron as well as some other valuable elements such as Zn, Pb and C are annually produced in the steelmaking industry. These alternative iron ore resources (fines) with unsatisfying physical and metallurgical properties are difficult to recycle. However, agglomerating these fines to be further used as a feed stock for existing iron and steelmaking processes is practiced successfully at several plants but for limited extent.
In the present study, briquettes of integrated steelmaking industry waste materials (namely, BF-dust and sludge, BOF-dust and sludge) were used as feed stock to produce direct reduced iron (DRI). Physical and metallurgical properties of produced briquettes were investigated by means of TGA/DTA/QMS in combination with XRD. Swelling, softening and melting behavior were also studied using heating microscope.
Keywords: Iron and Steel Wastes, Recycling, Self-Reducing Briquettes, Thermogravimetry.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23971309 A New Sufficient Conditions of Stability for Discrete Time Non-autonomous Delayed Hopfield Neural Networks
Authors: Adnene Arbi, Chaouki Aouiti, Abderrahmane Touati
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In this paper, we consider the uniform asymptotic stability, global asymptotic stability and global exponential stability of the equilibrium point of discrete Hopfield neural networks with delays. Some new stability criteria for system are derived by using the Lyapunov functional method and the linear matrix inequality approach, for estimating the upper bound of Lyapunov functional derivative.
Keywords: Hopfield neural networks, uniform asymptotic stability, global asymptotic stability, exponential stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19701308 A Lagrangian Hamiltonian Computational Method for Hyper-Elastic Structural Dynamics
Authors: Hosein Falahaty, Hitoshi Gotoh, Abbas Khayyer
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Performance of a Hamiltonian based particle method in simulation of nonlinear structural dynamics is subjected to investigation in terms of stability and accuracy. The governing equation of motion is derived based on Hamilton's principle of least action, while the deformation gradient is obtained according to Weighted Least Square method. The hyper-elasticity models of Saint Venant-Kirchhoff and a compressible version similar to Mooney- Rivlin are engaged for the calculation of second Piola-Kirchhoff stress tensor, respectively. Stability along with accuracy of numerical model is verified by reproducing critical stress fields in static and dynamic responses. As the results, although performance of Hamiltonian based model is evaluated as being acceptable in dealing with intense extensional stress fields, however kinds of instabilities reveal in the case of violent collision which can be most likely attributed to zero energy singular modes.
Keywords: Hamilton's principle of least action, particle based method, hyper-elasticity, analysis of stability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16701307 Numerical Analysis of Roughness Effect on Mini and Microchannels: Hydrodynamics and Heat Transfer
Authors: El-Ghalia Filali, Cherif Gadouche, Mohamed Tahar
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A three-dimensional numerical simulation of flow through mini and microchannels with designed roughness is conducted here. The effect of the roughness height (surface roughness), geometry, Reynolds number on the friction factor, and Nusselt number is investigated. The study is carried out by employing CFD software, CFX. Our work focuses on a water flow inside a circular mini-channel of 1 mm and microchannels of 500 and 100 m in diameter. The speed entry varies from 0.1 m/s to 20 m/s. The general trend can be observed that bigger sizes of roughness element lead to higher flow resistance. It is found that the friction factor increases in a nonlinear fashion with the increase in obstruction height. Particularly, the effect of roughness can no longer be ignored at relative roughness height higher than 3%. A significant increase in Poiseuille number is detected for all configurations considered. The same observation can be done for Nusselt number. The transition zone between laminar and turbulent flow depends on the channel diameter.Keywords: Heat transfer, hydrodynamics, micro-channel, roughness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17681306 Heavy Metal Contamination of the Landscape at the ─¢ubietová Deposit (Slovakia)
Authors: Peter Andráš, Adam Lichý, Jana Rusková, Lenka Matúšková
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The heavy metal contamination of the technogenous sediments and soils at the investigated dump-field show irregular planar distribution. Also the heavy metal content in the surface water, drainage water and in the groundwater was studied both in the dry as well as during the rainy periods. The cementation process causes substitution of iron by copper. Natural installation and development of plant species was observed at the old mine waste dumps, specific to the local chemical conditions such as low content of essential nutrients and high content of heavy metals. The individual parts of the plant tissues (roots, branches/stems, leaves/needles, flowers/ fruits) are contaminated by heavy metals and tissues are damaged differently, respectively.Keywords: Contamination, dump-field, heavy metals, plants, sediment, water.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 30821305 Computational Approaches for Ballistic Impact Response of Stainless Steel 304
Authors: A. Mostafa
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This paper presents a numerical study on determination of ballistic limit velocity (V50) of stainless steel 304 (SS 304) used in manufacturing security screens. The simulated ballistic impact tests were conducted on clamped sheets with different thicknesses using ABAQUS/Explicit nonlinear finite element (FE) package. The ballistic limit velocity was determined using three approaches, namely: numerical tests based on material properties, FE calculated residual velocities and FE calculated residual energies. Johnson-Cook plasticity and failure criterion were utilized to simulate the dynamic behaviour of the SS 304 under various strain rates, while the well-known Lambert-Jonas equation was used for the data regression for the residual velocity and energy model. Good agreement between the investigated numerical methods was achieved. Additionally, the dependence of the ballistic limit velocity on the sheet thickness was observed. The proposed approaches present viable and cost-effective assessment methods of the ballistic performance of SS 304, which will support the development of robust security screen systems.
Keywords: Ballistic velocity, stainless steel, numerical approaches, security screen.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6631304 Selection of Intensity Measure in Probabilistic Seismic Risk Assessment of a Turkish Railway Bridge
Authors: M. F. Yilmaz, B. Ö. Çağlayan
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Fragility curve is an effective common used tool to determine the earthquake performance of structural and nonstructural components. Also, it is used to determine the nonlinear behavior of bridges. There are many historical bridges in the Turkish railway network; the earthquake performances of these bridges are needed to be investigated. To derive fragility curve Intensity measures (IMs) and Engineering demand parameters (EDP) are needed to be determined. And the relation between IMs and EDP are needed to be derived. In this study, a typical simply supported steel girder riveted railway bridge is studied. Fragility curves of this bridge are derived by two parameters lognormal distribution. Time history analyses are done for selected 60 real earthquake data to determine the relation between IMs and EDP. Moreover, efficiency, practicality, and sufficiency of three different IMs are discussed. PGA, Sa(0.2s) and Sa(1s), the most common used IMs parameters for fragility curve in the literature, are taken into consideration in terms of efficiency, practicality and sufficiency.
Keywords: Railway bridges, earthquake performance, fragility analyses, selection of intensity measures.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9031303 Detection of Diabetic Symptoms in Retina Images Using Analog Algorithms
Authors: Daniela Matei, Radu Matei
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In this paper a class of analog algorithms based on the concept of Cellular Neural Network (CNN) is applied in some processing operations of some important medical images, namely retina images, for detecting various symptoms connected with diabetic retinopathy. Some specific processing tasks like morphological operations, linear filtering and thresholding are proposed, the corresponding template values are given and simulations on real retina images are provided.Keywords: Diabetic retinopathy, pathology detection, cellular neural networks, analog algorithms.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20791302 Effect of Synthetic Queen Mandibular Pheromone on Pollination of Cotton by Honey Bees, Apis mellifera
Authors: M. Keshlaf, R. Mensah, O. Nicetic, R. Spooner-Hart
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The effectiveness of a commercial bee attractant, synthetic honey bee queen mandibular pheromone (Fruit Boost®) for enhancing pollination of Gossypium hirsutum was evaluated in a transgenic (Bt) cotton crop. The study assessed the number of bee visitations to blossoms of plants treated with Fruit Boost® as well, as effects on fruit set, yield, and lint quality. Bee activity on plots sprayed with pheromone concentrations of 50 and 500 queen equivalents (QEQ) /ha did not differ significantly from water-only control, on the day of application or the subsequent day. Application of the pheromone did not increase fruit set, yield, or lint quality. Two consecutive pheromone applications, applied two days apart, were not significantly different from a single application for any parameter.
Keywords: Apis mellifera, cotton, pollination, QMP pheromone
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22611301 Seismic Fragility Curves for Shallow Circular Tunnels under Different Soil Conditions
Authors: Siti Khadijah Che Osmi, Syed Mohd Ahmad
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This paper presents a methodology to develop fragility curves for shallow tunnels so as to describe a relationship between seismic hazard and tunnel vulnerability. Emphasis is given to the influence of surrounding soil material properties because the dynamic behaviour of the tunnel mostly depends on it. Four ground properties of soils ranging from stiff to soft soils are selected. A 3D nonlinear time history analysis is used to evaluate the seismic response of the tunnel when subjected to five real earthquake ground intensities. The derived curves show the future probabilistic performance of the tunnels based on the predicted level of damage states corresponding to the peak ground acceleration. A comparison of the obtained results with the previous literature is provided to validate the reliability of the proposed fragility curves. Results show the significant role of soil properties and input motions in evaluating the seismic performance and response of shallow tunnels.
Keywords: Fragility analysis, seismic performance, tunnel lining, vulnerability.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13901300 The Determination of Heavy Metal in Herb Used in Dusit Community to Develop a Sustainable Quality of Life
Authors: Chinnawat Satsananan
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This research aimed to find amount of heavy metal in herb used in Dusit community and compare of heavy metal in each part by quantity in herb and standard determination in Thai herb books to develop a sustainable quality of life, the result of study in 14 herbs do not find sample of heavy metal., by quantity of heavy contamination of 4 kinds: Cd, Co, Fe and Pb have lower than standard of 2 organizations: Thai herb standard, and World Health Organization, from the test 14 herbs have Fe in every part of herbs and all 14 kinds has Fe that is necessary for our health.
Keywords: Herbs Plants, Heavy Metal, Dusit District
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18371299 H-Infinity and RST Position Controllers of Rotary Traveling Wave Ultrasonic Motor
Authors: M. Brahim, I. Bahri, Y. Bernard
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Traveling Wave Ultrasonic Motor (TWUM) is a compact, precise, and silent actuator generating high torque at low speed without gears. Moreover, the TWUM has a high holding torque without supply, which makes this motor as an attractive solution for holding position of robotic arms. However, their nonlinear dynamics, and the presence of load-dependent dead zones often limit their use. Those issues can be overcome in closed loop with effective and precise controllers. In this paper, robust H-infinity (H∞) and discrete time RST position controllers are presented. The H∞ controller is designed in continuous time with additional weighting filters to ensure the robustness in the case of uncertain motor model and external disturbances. Robust RST controller based on the pole placement method is also designed and compared to the H∞. Simulink model of TWUM is used to validate the stability and the robustness of the two proposed controllers.
Keywords: Piezoelectric motors, position control, H∞, RST, stability criteria, robustness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9641298 Investigation into Behavior of Suspen-Domes in Comparison with Single-Layer Domes
Authors: Behnam Shirkhanghah, Ali Darabadi-Zare, Houshyar Eimani-Kalesar, Babak Pahlevan
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Prestressing in structure increases ratio of load-bearing capacity to weight. Suspendomes are single-layer braced domes reinforced with cable and strut. Prestressing of cables alter value and distribution of stress in structure. In this study two configuration, diamatic and lamella domes is selected. Investigated domes have span of 100m with rise-to-span ratios of 0.1, 0.2, and 0.3. Single layer domes loaded under service load combinations according to ISO code. After geometric nonlinear analysis, models are designed with tubular and I-shaped sections then reinforced with cable and strut and converted to suspendomes. Displacements and stresses of some groups of nodes and elements in all of single-layer domes and suspendomes for three load combinations, symmetric snow, asymmetric snow and wind are compared. Variation due to suspending system is investigated. Suspendomes are redesigned and minimum possible weight after addition of cable and strut is obtained.
Keywords: Braced dome, Prestressing, Single-layer, Suspendome.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28731297 Role of Biorefining and Biomass Utilization in Environmental Control
Authors: Subir Kundu, Sukhendra Singh, Sumedha Ojha, Kanika Kundu
Abstract:
The continuous decline of petroleum and natural gas reserves and non linear rise of oil price has brought about a realisation of the need for a change in our perpetual dependence on the fossil fuel. A day to day increased consumption of crude and petroleum products has made a considerable impact on our foreign exchange reserves. Hence, an alternate resource for the conversion of energy (both liquid and gas) is essential for the substitution of conventional fuels. Biomass is the alternate solution for the present scenario. Biomass can be converted into both liquid as well as gaseous fuels and other feedstocks for the industries.
Keywords: Bioenergy, Biomass conversion, Biorefining, Efficient utilisation of night soil.
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