Search results for: Ceramic material
492 Urban and Rural Children’s Knowledge on Biodiversity in Bizkaia: Tree Identification Skills and Animal and Plant Listing
Authors: Joserra Díez, Ainhoa Meñika, Iñaki Sanz-Azkue, Arritokieta Ortuzar
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Biodiversity provides humans with a great range of ecosystemic services; it is therefore an indispensable resource and a legacy to coming generations. However, in the last decades, the increasing exploitation of the Planet has caused a great loss of biodiversity and its acquaintance has decreased remarkably; especially in urbanized areas, due to the decreasing attachment of humans to nature. Yet, the Primary Education curriculum primes the identification of flora and fauna to guarantee the knowledge of children on their surroundings, so that they care for the environment as well as for themselves. In order to produce effective didactic material that meets the needs of both teachers and pupils, it is fundamental to diagnose the current situation. In the present work, the knowledge on biodiversity of 3rd cycle Primary Education students in Biscay (n=98) and its relation to the size of the town/city of their school is discussed. Two tests have been used with such aim: one for tree identification and the other one so that the students enumerated the species of trees and animals they knew. Results reveal that knowledge of students on tree identification is scarce regardless the size of the city/town and of their school. On the other hand, animal species are better known than tree species.Keywords: Biodiversity, population, tree identification, animal identification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1163491 Thermal Analysis of Circular Pin-fin with Rectangular Slot at the Center by Forced Convection
Authors: Kavita H. Dhanawade, Hanamant S. Dhanawade, Ajay Kashikar, Shweta Matey, Mahesh Bhadane, Sunny Sarraf
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Extended surfaces are commonly used in practice to enhance heat transfer. Most of the engineering problems require high performance heat transfer components with light weight, volumes, accommodating shapes, costs and reliability depending on industrial applications. This paper reports an experimental analysis to investigate heat transfer enhancement by forced convection using different sizes of pin-fin with rectangular slots at the center. The cross sectional area of the oblong duct was 200 mm x 80 mm. The info utilized in performance analysis was obtained experimentally for material, aluminum at 200 Watts heat input varying velocity 1 m/s to 5 m/s. Using the Taguchi experimental design method, optimum design parameters and their levels were analysed. Nusselt number and friction factor were considered as a performance characteristic parameter. An An L9 (33) orthogonal array was designated as an experimental proposal. Optimum results were found by experimenting. It is observed that pin-fins with different slots sizes have a better impact on Nusselt Number.Keywords: Heat transfer coefficient, Nusselt Number, pin-fin, forced convection.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 776490 A 3 Dimensional Simulation of the Repeated Load Triaxial Test
Authors: Bao Thach Nguyen, Abbas Mohajerani
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A typical flexible pavement structure consists of the surface, base, sub-base and subgrade soil. The loading traffic is transferred from the top layer with higher stiffness to the layer below with less stiffness. Under normal traffic loading, the behaviour of flexible pavement is very complex and can be predicted by using the repeated load triaxial test equipment in the laboratory. However, the nature of the repeated load triaxial testing procedure is considered time-consuming, complicated and expensive, and it is a challenge to carry out as a routine test in the laboratory. Therefore, the current paper proposes a numerical approach to simulate the repeated load triaxial test by employing the discrete element method. A sample with particle size ranging from 2.36mm to 19.0mm was constructed. Material properties, which included normal stiffness, shear stiffness, coefficient of friction, maximum dry density and particle density, were used as the input for the simulation. The sample was then subjected to a combination of deviator and confining stress and it was found that the discrete element method is able to simulate the repeated load triaxial test in the laboratory.
Keywords: Discrete element method, repeated load triaxial, pavement materials.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3139489 Control of Building Ventilation with CO2 Gas Sensors Based on Doped Magnesium Ferrite Nanoparticles for the Development of Construction and Infrastructure Industry
Authors: Maryam Kiani, Abdul Basit Kiani
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To develop construction and infrastructure industry, sensors are highly desired to control building ventilation. Zinc doped magnesium ferrite nanoparticles (Z@MFO) (Zn = 0.0, 0.2, 0.3, 0.4) were prepared in this paper. Structural analyses confirmed the formation of spinel cubic nanostructures. X-Ray diffraction (XRD) data represent high reactive surface area due to small average particle size about 15 nm, which efficiently influences the gas sensing mechanism. The gas sensing property of Z@MFO for several gases was obtained by measuring the resistance as a function of different factors, such as composition and response time in air and in presence of gas. The sensitivity of spinel ferrite to CO2 at room temperature has been compared. The Z@MFO nano-structure exhibited high sensitivity represented good response time of (~1 min) to CO2, demonstrated that the material can be used in the field of gas sensors with high sensitivity and good selectivity at room temperature to control building ventilation. CO2 gas sensors play a vital role in ensuring the safety, comfort, and sustainability of modern building environments.
Keywords: MgFe2O4 nanoparticles, synthesis, gas sensing properties, X ray differentiation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 168488 Application of Flexi-Wall in Noise Barriers Renewal
Authors: B. Daee, H. M. El Naggar
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This paper presents an experimental study on structural performance of an innovative noise barrier consisting of poly-block, light polyurethane foam (LPF) and polyurea. This wall system (flexi-wall) is intended to be employed as a vertical extension to existing sound barriers in an accelerated construction method. To aid in the wall design, several mechanical tests were conducted on LPF specimens and two full-scale walls were then fabricated employing the same LPF material. The full-scale walls were subjected to lateral loading in order to establish their lateral resistance. A cyclic fatigue test was also performed on a full-scale flexi-wall in order to evaluate the performance of the wall under a repetitive loading condition. The result of the experiments indicated the suitability of flexi-wall in accelerated construction and confirmed that the structural performance of the wall system under lateral loading is satisfactory for the sound barrier application. The experimental results were discussed and a preliminary design procedure for application of flexi-wall in sound barrier applications was also developed.Keywords: Noise barrier, Polyurethane Foam, Accelerated construction, Full-scale experiment.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1929487 Gas Condensing Unit with Inner Heat Exchanger
Authors: Dagnija Blumberga, Toms Prodanuks, Ivars Veidenbergs, Andra Blumberga
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Gas condensing units with inner tubes heat exchangers represent third generation technology and differ from second generation heat and mass transfer units, which are fulfilled by passive filling material layer. The first one improves heat and mass transfer by increasing cooled contact surface of gas and condensate drops and film formed in inner tubes heat exchanger. This paper presents a selection of significant factors which influence the heat and mass transfer. Experimental planning is based on the research and analysis of main three independent variables; velocity of water and gas as well as density of spraying. Empirical mathematical models show that the coefficient of heat transfer is used as dependent parameter which depends on two independent variables; water and gas velocity. Empirical model is proved by the use of experimental data of two independent gas condensing units in Lithuania and Russia. Experimental data are processed by the use of heat transfer criteria-Kirpichov number. Results allow drawing the graphical nomogram for the calculation of heat and mass transfer conditions in the innovative and energy efficient gas cooling unit.
Keywords: Gas condensing unit, filling, inner heat exchanger, package, spraying, tunes.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1443486 Dependence of Equilibrium, Kinetics and Thermodynamics of Zn (II) Ions Sorption from Water on Particle Size of Natural Hydroxyapatite Extracted from Bone Ash
Authors: Reza Bazargan-Lari, Mohammad Ebrahim Bahrololoom, Afshin Nemati
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Heavy metals have bad effects on environment and soils and it can uptake by natural HAP .natural Hap is an inexpensive material that uptake large amounts of various heavy metals like Zn (II) .Natural HAP (N-HAP), extracted from bovine cortical bone ash, is a good choice for substitution of commercial HAP. Several experiments were done to investigate the sorption capacity of Zn (II) to N-HAP in various particles sizes, temperatures, initial concentrations, pH and reaction times. In this study, the sorption of Zinc ions from a Zn solution onto HAP particles with sizes of 1537.6 nm and 47.6 nm at three initial pH values of 4.50, 6.00 and 7.50 was studied. The results showed that better performance was obtained through a 47.6 nm particle size and higher pH values. The experimental data were analyzed using Langmuir, Freundlich, and Arrhenius equations for equilibrium, kinetic and thermodynamic studies. The analysis showed a maximum adsorption capacity of NHAP as being 1.562 mmol/g at a pH of 7.5 and small particle size. Kinetically, the prepared N-HAP is a feasible sorbent that retains Zn (II) ions through a favorable and spontaneous sorption process.Keywords: Natural Hydroxyapatite, Heavy metal ions, Adsorption, Zn removal, kinetic model, bone ash
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2138485 Stress and Strain Analysis of Notched Bodies Subject to Non-Proportional Loadings
Authors: A. Ince
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In this paper, an analytical simplified method for calculating elasto-plastic stresses strains of notched bodies subject to non-proportional loading paths is discussed. The method was based on the Neuber notch correction, which relates the incremental elastic and elastic-plastic strain energy densities at the notch root and the material constitutive relationship. The validity of the method was presented by comparing computed results of the proposed model against finite element numerical data of notched shaft. The comparison showed that the model estimated notch-root elasto-plastic stresses strains with good accuracy using linear-elastic stresses. The prosed model provides more efficient and simple analysis method preferable to expensive experimental component tests and more complex and time consuming incremental non-linear FE analysis. The model is particularly suitable to perform fatigue life and fatigue damage estimates of notched components subjected to nonproportional loading paths.Keywords: Elasto-plastic, stress-strain, notch analysis, nonprortional loadings, cyclic plasticity, fatigue.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2541484 Optimization of Process Parameters Affecting on Spring-Back in V-Bending Process for High Strength Low Alloy Steel HSLA 420 Using FEA (HyperForm) and Taguchi Technique
Authors: Navajyoti Panda, R. S. Pawar
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In this study, process parameters like punch angle, die opening, grain direction, and pre-bend condition of the strip for deep draw of high strength low alloy steel HSLA 420 are investigated. The finite element method (FEM) in association with the Taguchi and the analysis of variance (ANOVA) techniques are carried out to investigate the degree of importance of process parameters in V-bending process for HSLA 420&ST12 grade material. From results, it is observed that punch angle had a major influence on the spring-back. Die opening also showed very significant role on spring back. On the other hand, it is revealed that grain direction had the least impact on spring back; however, if strip from flat sheet is taken, then it is less prone to spring back as compared to the strip from sheet metal coil. HyperForm software is used for FEM simulation and experiments are designed using Taguchi method. Percentage contribution of the parameters is obtained through the ANOVA techniques.
Keywords: Bending, V-bending, FEM, spring-back, Taguchi, HyperForm, profile projector, HSLA 420 & St12 materials.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1423483 Stabilization of Fly Ash Slope Using Plastic Recycled Polymer and Finite Element Analysis Using Plaxis 3D
Authors: Tushar Vasant Salunkhe, Sariput M. Nawghare, Maheboobsab B. Nadaf, Sushovan Dutta, J. N. Mandal
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The model tests were conducted in the laboratory without and with Plastic recycled polymer in fly ash steep slopes overlaying soft foundation soils like fly ash and powai soil in order to check the stability of steep slope. In this experiment, fly ash is used as a filling material and Plastic Recycled Polymers of diameter = 3mm and length = 4mm were made from waste plastic product (lower grade plastic product). The properties of fly ash and Plastic recycled polymers are determined. From the experiments, load and settlement have measured. From these data, load –settlement curves have reported. It has been observed from test results that load carrying capacity of mixture fly ash with Plastic Recycled Polymers slope is more than that of fly ash slope. The deformation of Plastic Recycled Polymers slope is slightly more than that of fly ash slope. A Finite Element Method (F.E.M.) was also evaluated using PLAXIS 3D version. The failure pattern, deformations and factor of safety are reported based on analytical programme. The results from experimental data and analytical programme are compared and reported.Keywords: Fly ash, Plastic recycled polymer, Factor of safety, Finite element method (FEM), Bishop’s simplified method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2525482 Model the Off-Shore Ocean-Sea Waves to Generate Electric Power by Design of a Converting Device
Authors: Muthana A. M. Jameel Al-Jaboori
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In this paper, we will present a mathematical model to design a system able to generate electricity from ocean-sea waves. We will use the basic principles of the transfer of the energy potential of waves in a chamber to force the air inside a vertical or inclined cylindrical column, which is topped by a wind turbine to rotate the electric generator. The present mathematical model included a high number of variables such as the wave, height, width, length, velocity, and frequency, as well as others for the energy cylindrical column, like varying diameters and heights, and the wave chamber shape diameter and height. While for the wells wind turbine the variables included the number of blades, length, width, and clearance, as well as the rotor and tip radius. Additionally, the turbine rotor and blades must be made from the light and strong material for a smooth blade surface. The variables were too vast and high in number. Then the program was run successfully within the MATLAB and presented very good modeling results.Keywords: Water wave, model, wells turbine, MATLAB program, results.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1163481 InAlGaN Quaternary Multi-Quantum Wells UVLaser Diode Performance and Characterization
Authors: S. M. Thahab, H. Abu Hassan, Z. Hassan
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The InAlGaN alloy has only recently began receiving serious attention into its growth and application. High quality InGaN films have led to the development of light emitting diodes (LEDs) and blue laser diodes (LDs). The quaternary InAlGaN however, represents a more versatile material since the bandgap and lattice constant can be independently varied. We report an ultraviolet (UV) quaternary InAlGaN multi-quantum wells (MQWs) LD study by using the simulation program of Integrated System Engineering (ISE TCAD). Advanced physical models of semiconductor properties were used in order to obtain an optimized structure. The device performance which is affected by piezoelectric and thermal effects was studied via drift-diffusion model for carrier transport, optical gain and loss. The optical performance of the UV LD with different numbers of quantum wells was numerically investigated. The main peak of the emission wavelength for double quantum wells (DQWs) was shifted from 358 to 355.8 nm when the forward current was increased. Preliminary simulated results indicated that better output performance and lower threshold current could be obtained when the quantum number is four, with output power of 130 mW and threshold current of 140 mA.Keywords: Nitride semiconductors, InAlGaN quaternary, UVLD, numerical simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1927480 Investigation of Optimal Parameter Settings in Super Duplex Welding
Authors: R. M. Chandima Ratnayake, Daniel Dyakov
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Super steel materials play a vital role in the construction and fabrication of structural, piping and pipeline components. In assuring the integrity of onshore and offshore operating systems, they enable life cycle costs to be minimized. In this context, Duplex stainless steel (DSS) material related welding on constructions and fabrications plays a significant role in maintaining and assuring integrity at an optimal expenditure over the life cycle of production and process systems as well as associated structures. In DSS welding, factors such as gap geometry, shielding gas supply rate, welding current, and type of the welding process are vital to the final joint performance. Hence, an experimental investigation has been performed using an engineering robust design approach (ERDA) to investigate the optimal settings that generate optimal super DSS (i.e. UNS S32750) joint performance. This manuscript illustrates the mathematical approach and experimental design, optimal parameter settings and results of the verification experiment.Keywords: Duplex stainless steel welding, engineering robust design, mathematical framework, optimal parameter settings.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1787479 Investigations on the Seismic Performance of Hot-Finished Hollow Steel Sections
Authors: Paola Pannuzzo, Tak-Ming Chan
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In seismic applications, hollow steel sections show, beyond undeniable esthetical appeal, promising structural advantages since, unlike open section counterparts, they are not susceptible to weak-axis and lateral-torsional buckling. In particular, hot-finished hollow steel sections have homogeneous material properties and favorable ductility but have been underutilized for cyclic bending. The main reason is that the parameters affecting their hysteretic behaviors are not yet well understood and, consequently, are not well exploited in existing codes of practice. Therefore, experimental investigations have been conducted on a wide range of hot-finished rectangular hollow section beams with the aim to providing basic knowledge for evaluating their seismic performance. The section geometry (width-to-thickness and depth-to-thickness ratios) and the type of loading (monotonic and cyclic) have been chosen as the key parameters to investigate the cyclic effect on the rotational capacity and to highlight the differences between monotonic and cyclic load conditions. The test results provide information on the parameters that affect the cyclic performance of hot-finished hollow steel beams and can be used to assess the design provisions stipulated in the current seismic codes of practice.
Keywords: Hot-finished steel, hollow sections, cyclic tests, bending.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 556478 Hydrogen Embrittlement in a Coupled Mass Diffusion with Stress near a Blunting Crack Tip for AISI 4135 Pressure Vessel
Authors: H. Dehghan, E. Mahdavi, M. M. Heyhat
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In pressure vessels contain hydrogen, the role of hydrogen will be important because of hydrogen cracking problem. It is difficult to predict what is happened in metallurgical field spite of a lot of studies have been searched. The main role in controlling the mass diffusion as driving force is related to stress. In this study, finite element analysis is implemented to estimate material-s behavior associated with hydrogen embrittlement. For this purpose, one model of a pressure vessel is introduced that it has definite boundary and initial conditions. In fact, finite element is employed to solve the sequentially coupled mass diffusion with stress near a crack front in a pressure vessel. Modeling simulation intergrarnular fracture of AISI 4135 steel due to hydrogen is investigated. So, distribution of hydrogen and stress are obtained and they indicate that their maximum amounts occur near the crack front. This phenomenon is happened exactly the region between elastic and plastic field. Therefore, hydrogen is highly mobile and can diffuse through crystal lattice so that this zone is potential to trap high volume of hydrogen. Consequently, crack growth and fast fracture will be happened.Keywords: Stress Intensity Factor, Mass Diffusion, FEM, Pressure Vessel
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3064477 Effect of Uneven Surface on Magnetic Properties of Fe-Based Amorphous Transformer
Authors: Yeong-Hwa Chang, Chang-Hung Hsu, Huei-Lung Chu, Chia-Wen Chang, Wei-Shou Chan, Chun-Yao Lee; Chia-Shiang Yao, Yan-Lou He
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This study reports the preparation of soft magnetic ribbons of Fe-based amorphous alloys using the single-roller melt-spinning technique. Ribbon width varied from 142 mm to 213 mm and, with a thickness of approximately 22 μm 2 μm. The microstructure and magnetic properties of the ribbons were characterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and electrical resistivity measurements (ERM). The amorphous material properties dependence of the cooling rate and nozzle pressure have uneven surface in ribbon thicknesses are investigated. Magnetic measurement results indicate that some region of the ribbon exhibits good magnetic properties, higher saturation induction and lower coercivity. However, due to the uneven surface of 213 mm wide ribbon, the magnetic responses are not uniformly distributed. To understand the transformer magnetic performances, this study analyzes the measurements of a three-phase 2 MVA amorphous-cored transformer. Experimental results confirm that the transformer with a ribbon width of 142 mm has better magnetic properties in terms of lower core loss, exciting power, and audible noise.
Keywords: Amorphous ribbon, uneven surface, magnetic properties, and rapid solidification
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2168476 Improving Gas Separation Performance of Poly(Vinylidene Fluoride) Based Membranes Containing Ionic Liquid
Authors: S. Al-Enezi, J. Samuel, A. Al-Banna
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Polymer based membranes are one of the low-cost technologies available for the gas separation. Three major elements required for a commercial gas separating membrane are high permeability, high selectivity, and good mechanical strength. Poly(vinylidene fluoride) (PVDF) is a commercially available fluoropolymer and a widely used membrane material in gas separation devices since it possesses remarkable thermal, chemical stability, and excellent mechanical strength. The PVDF membrane was chemically modified by soaking in different ionic liquids and dried. The thermal behavior of modified membranes was investigated by differential scanning calorimetry (DSC), and thermogravimetry (TGA), and the results clearly show the best affinity between the ionic liquid and the polymer support. The porous structure of the PVDF membranes was clearly seen in the scanning electron microscopy (SEM) images. The CO₂ permeability of blended membranes was explored in comparison with the unmodified matrix. The ionic liquid immobilized in the hydrophobic PVDF support exhibited good performance for separations of CO₂/N₂. The improved permeability of modified membrane (PVDF-IL) is attributed to the high concentration of nitrogen rich imidazolium moieties.
Keywords: PVDF, gas permeability, polymer membrane, ionic liquid.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1024475 Effects of Different Sowing Dates on Oil Yield of Castor (Ricinus communis L.)
Authors: Ö. Öztürk, G. P. Gerem, A. Yenici, B. Haspolat
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Castor (Ricinus communis L.) is one of the important non-edible oilseed crops having immense industrial and medicinal value. Oil yield per unit area is the ultimate target in growing oilseed plants and sowing date is one of the important factors which have a clear role on production of active substances particularly in oilseeds. This study was conducted to evaluate the effect of sowing date on the seed and oil yield of castor in Central Anatolia of Turkey in 2011. The field experiment was set up in a completely randomized block design with three replications. Black Diamond-2 castor cultivar was used as plant material. The treatment was four sowing dates of May 10, May 25, June 10, June 25. In this research; seed yield, oil content and oil yield were investigated. Results showed that the effect of different sowing dates were significant on all of characteristics. In general; delayed sowing dates, resulted in decreased seed yield, oil content and oil yield. The highest value of seed yield, oil content and oil yield (respectively, 2523.7 kg ha-1, 51.18% and 1292.2 kg ha-1) were obtained from the first sowing date (May 10) while the lowest seed yield, oil content and oil yield (respectively, 1550 kg ha-1, 43.67%, 677.3 kg ha-1) were recorded from the latest sowing date (June 25). Therefore, it can be concluded that early May could be recommended as an appropriate sowing date in the studied location and similar climates for achieved high oil yield of castor.
Keywords: Castor bean, Ricinus communis L., sowing date, seed yield, oil content.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3208474 Research on the Impact on Building Temperature and Ventilation by Outdoor Shading Devices in Hot-Humid Area: Through Measurement and Simulation on an Office Building in Guangzhou
Authors: Hankun Lin, Yiqiang Xiao, Qiaosheng Zhan
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Shading devices (SDs) are widely used in buildings in the hot-humid climate areas for reducing cooling energy consumption for interior temperature, as the result of reducing the solar radiation directly. Contrasting the surface temperature of materials of SDs to the glass on the building façade could give more analysis for the shading effect. On the other side, SDs are much more used as the independence system on building façade in hot-humid area. This typical construction could have some impacts on building ventilation as well. This paper discusses the outdoor SDs’ effects on the building thermal environment and ventilation, through a set of measurements on a 2-floors office building in Guangzhou, China, which install a dynamic aluminum SD-system around the façade on 2nd-floor. The measurements recorded the in/outdoor temperature, relative humidity, velocity, and the surface temperature of the aluminum panel and the glaze. After that, a CFD simulation was conducted for deeper discussion of ventilation. In conclusion, this paper reveals the temperature differences on the different material of the façade, and finds that the velocity of indoor environment could be reduced by the outdoor SDs.
Keywords: Outdoor shading devices, hot-humid area, temperature, ventilation, measurement, CFD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1001473 Effect of U-Turn in Reinforced Concrete Dog-Legged Stair Slabs
Authors: Abdul Baqi, Zaid Mohammad
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Reinforced concrete stair slabs with mid landings i.e. Dog-legged shaped are conventionally designed as per specifications of standard codes of practices which guide about the effective span according to the varying support conditions. Presently, the behavior of such slabs has been investigated using Finite Element method. A single flight stair slab with landings on both sides and supported at ends on wall, and a multi flight stair slab with landings and six different support arrangements have been analyzed. The results obtained for stresses, strains and deflections are used to describe the behavior of such stair slabs, including locations of critical moments and deflections. Values of critical moments obtained by F.E. analysis have also have been compared with that obtained from conventional analysis. Analytical results show that the moments are also critical near the kinks i.e. junction of mid-landing and inclined waist slab. This change in the behavior of dog-legged stair slab may be due to continuity of the material in transverse direction in two landings adjoining the waist slab, hence additional stiffness achieved. This change in the behavior is generally not taken care of in conventional method of design.Keywords: Dog-legged, Stair slab, F.E. Analysis, Landing, Reinforced concrete.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4541472 Micro-Controller Based Oxy-Fuel Profile Cutting System
Authors: A. P. Kulkarni, P. Randive, A. R. Mache
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In today-s era of plasma and laser cutting, machines using oxy-acetylene flame are also meritorious due to their simplicity and cost effectiveness. The objective to devise a Computer controlled Oxy-Fuel profile cutting machine arose from the increasing demand for metal cutting with respect to edge quality, circularity and lesser formation of redeposit material. The System has an 8 bit micro controller based embedded system, which assures stipulated time response. A new window based Application software was devised which takes a standard CAD file .DXF as input and converts it into numerical data required for the controller. It uses VB6 as a front end whereas MS-ACCESS and AutoCAD as back end. The system is designed around AT89C51RD2, powerful 8 bit, ISP micro controller from Atmel and is optimized to achieve cost effectiveness and also maintains the required accuracy and reliability for complex shapes. The backbone of the system is a cleverly designed mechanical assembly along with the embedded system resulting in an accuracy of about 10 microns while maintaining perfect linearity in the cut. This results in substantial increase in productivity. The observed results also indicate reduced inter laminar spacing of pearlite with an increase in the hardness of the edge region.
Keywords: Computer-Control, Profile, Oxy-Fuel.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2570471 An Investigation on Thermo Chemical Conversions of Solid Waste for Energy Recovery
Authors: Sharmina Begum, M. G. Rasul, Delwar Akbar
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Solid waste can be considered as an urban burden or as a valuable resource depending on how it is managed. To meet the rising demand for energy and to address environmental concerns, a conversion from conventional energy systems to renewable resources is essential. For the sustainability of human civilization, an environmentally sound and techno-economically feasible waste treatment method is very important to treat recyclable waste. Several technologies are available for realizing the potential of solid waste as an energy source, ranging from very simple systems for disposing of dry waste to more complex technologies capable of dealing with large amounts of industrial waste. There are three main pathways for conversion of waste material to energy: thermo chemical, biochemical and physicochemical. This paper investigates the thermo chemical conversion of solid waste for energy recovery. The processes, advantages and dis-advantages of various thermo chemical conversion processes are discussed and compared. Special attention is given to Gasification process as it provides better solutions regarding public acceptance, feedstock flexibility, near-zero emissions, efficiency and security. Finally this paper presents comparative statements of thermo chemical processes and introduces an integrated waste management system.Keywords: Gasification, Incineration, Pyrolysis, Thermo chemical conversion.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3272470 Effect of Uneven Surface on Magnetic Properties of Fe-based Amorphous Power Transformer
Authors: Chang-Hung Hsu, Yeong-Hwa Chang, Chun-Yao Lee, Chia-Shiang Yao, Yan-Lou He, Huei-Lung Chu, Chia-Wen Chang, Wei-Shou Chan
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This study reports the preparation of soft magnetic ribbons of Fe-based amorphous alloys using the single-roller melt-spinning technique. Ribbon width varied from 142 mm to 213 mm and, with a thickness of approximately 22 μm ± 2 μm. The microstructure and magnetic properties of the ribbons were characterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and electrical resistivity measurements (ERM). The amorphous material properties dependence of the cooling rate and nozzle pressure have uneven surface in ribbon thicknesses are investigated. Magnetic measurement results indicate that some region of the ribbon exhibits good magnetic properties, higher saturation induction and lower coercivity. However, due to the uneven surface of 213 mm wide ribbon, the magnetic responses are not uniformly distributed. To understand the transformer magnetic performances, this study analyzes the measurements of a three-phase 2 MVA amorphous-cored transformer. Experimental results confirm that the transformer with a ribbon width of 142 mm has better magnetic properties in terms of lower core loss, exciting power, and audible noise.Keywords: Amorphous ribbon, uneven surface, magnetic properties, and rapid solidification
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1996469 Derivation of Empirical Formulae to Predict Pressure and Impulsive Asymptotes for P-I Diagrams of One-way RC Panels
Authors: Azrul A. Mutalib, Masoud Abedini, Shahrizan Baharom, Hong Hao
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There are only limited studies that directly correlate the increase in reinforced concrete (RC) panel structural capacities in resisting the blast loads with different RC panel structural properties in terms of blast loading characteristics, RC panel dimensions, steel reinforcement ratio and concrete material strength. In this paper, numerical analyses of dynamic response and damage of the one-way RC panel to blast loads are carried out using the commercial software LS-DYNA. A series of simulations are performed to predict the blast response and damage of columns with different level and magnitude of blast loads. The numerical results are used to develop pressureimpulse (P-I) diagrams of one-way RC panels. Based on the numerical results, the empirical formulae are derived to calculate the pressure and impulse asymptotes of the P-I diagrams of RC panels. The results presented in this paper can be used to construct P-I diagrams of RC panels with different concrete and reinforcement properties. The P-I diagrams are very useful to assess panel capacities in resisting different blast loads.
Keywords: One-way reinforced concrete (RC) panels, Explosive loads, LS-DYNA Software, Pressure-Impulse (P-I) diagram, Numerical.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2748468 MIMCA: A Modelling and Simulation Approach in Support of the Design and Construction of Manufacturing Control Systems Using Modular Petri net
Authors: S. Ariffin, K. Hasnan, R.H. Weston
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A new generation of manufacturing machines so-called MIMCA (modular and integrated machine control architecture) capable of handling much increased complexity in manufacturing control-systems is presented. Requirement for more flexible and effective control systems for manufacturing machine systems is investigated and dimensioned-which highlights a need for improved means of coordinating and monitoring production machinery and equipment used to- transport material. The MIMCA supports simulation based on machine modeling, was conceived by the authors to address the issues. Essentially MIMCA comprises an organized unification of selected architectural frameworks and modeling methods, which include: NISTRCS, UMC and Colored Timed Petri nets (CTPN). The unification has been achieved; to support the design and construction of hierarchical and distributed machine control which realized the concurrent operation of reusable and distributed machine control components; ability to handle growing complexity; and support requirements for real- time control systems. Thus MIMCA enables mapping between 'what a machine should do' and 'how the machine does it' in a well-defined but flexible way designed to facilitate reconfiguration of machine systems.Keywords: Machine control, architectures, Petri nets, modularity, modeling, simulation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1578467 Construct the Fur Input Mixed Model with Activity-Based Benefit Assessment Approach of Leather Industry
Authors: M. F. Wu, F. T. Cheng
Abstract:
Leather industry is the most important traditional industry to provide the leather products in the world for thousand years. The fierce global competitive environment and common awareness of global carbon reduction make livestock supply quantities falling, salt and wet blue leather material reduces and the price skyrockets significantly. Exchange rate fluctuation led sales revenue decreasing which due to the differences of export exchanges and compresses the overall profitability of leather industry. This paper applies activity-based benefit assessment approach to build up fitness fur input mixed model, fur is Wet Blue, which concerned with four key factors: the output rate of wet blue, unit cost of wet blue, yield rate and grade level of Wet Blue to achieve the low cost strategy under given unit price of leather product condition of the company. The research findings indicate that applying this model may improve the input cost structure, decrease numbers of leather product inventories and to raise the competitive advantages of the enterprise in the future.
Keywords: Activity-Based Benefit Assessment Approach, Input mixed, Output Rate, Wet Blue.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1651466 The Emission Spectra Due to Exciton-Exciton Collisions in GaAs/AlGaAs Quantum Well System
Authors: Surendra K Pandey
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Optical emission based on excitonic scattering processes becomes important in dense exciton systems in which the average distance between excitons is of the order of a few Bohr radii but still below the exciton screening threshold. The phenomena due to interactions among excited states play significant role in the emission near band edge of the material. The theory of two-exciton collisions for GaAs/AlGaAs quantum well systems is a mild attempt to understand the physics associated with the optical spectra due to excitonic scattering processes in these novel systems. The four typical processes considered give different spectral shape, peak position and temperature dependence of the emission spectra. We have used the theory of scattering together with the second order perturbation theory to derive the radiative power spontaneously emitted at an energy ħω by these processes. The results arrived at are purely qualitative in nature. The intensity of emitted light in quantum well systems varies inversely to the square of temperature, whereas in case of bulk materials it simply decreases with the temperature.
Keywords: Exciton-Exciton Collisions, Excitonic Scattering Processes, Interacting Excitonic States, Quantum Wells.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1426465 Comparison between the Efficiency of Heterojunction Thin Film InGaP\GaAs\Ge and InGaP\GaAs Solar Cell
Authors: F. Djaafar, B. Hadri, G. Bachir
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This paper presents the design parameters for a thin film 3J InGaP/GaAs/Ge solar cell with a simulated maximum efficiency of 32.11% using Tcad Silvaco. Design parameters include the doping concentration, molar fraction, layers’ thickness and tunnel junction characteristics. An initial dual junction InGaP/GaAs model of a previous published heterojunction cell was simulated in Tcad Silvaco to accurately predict solar cell performance. To improve the solar cell’s performance, we have fixed meshing, material properties, models and numerical methods. However, thickness and layer doping concentration were taken as variables. We, first simulate the InGaP\GaAs dual junction cell by changing the doping concentrations and thicknesses which showed an increase in efficiency. Next, a triple junction InGaP/GaAs/Ge cell was modeled by adding a Ge layer to the previous dual junction InGaP/GaAs model with an InGaP /GaAs tunnel junction.
Keywords: Heterojunction, modeling, simulation, thin film, Tcad Silvaco.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1229464 Deformation and Crystallization in a 7075-T651 Friction Stir Weld
Authors: C. S. Paglia
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The deformation and the crystallization in a 7075-T651 friction stir weld, in particular for regions directly in contact with the mechanical action of the rotating probe, have been investigated by means of optical microscopy. The investigation enabled to identify regions of the weld differently affected by the deformation caused by the welding process. The highly deformed grains in the horizontal direction close to the plate margin were indicative of shear movements along the horizontal plane, while highly deformed grains along the plate margin in the vertical direction were indicative of vertical shear movements of opposite directions, which superimposed the shear movement along the horizontal plane. The vertical shear movements were not homogeneous through the plate thickness. The microstructure indicated that after the probe passes, the grain growth may take place under static conditions. The small grains microstructure of the nugget region, formed after the main dynamic recrystallization process, develops to an equiaxed microstructure. A material transport influenced by the rotating shoulder was also observed from the trailing to the advancing side of the weld.
Keywords: AA7075-T651, friction stir welding, deformation, crystallization.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 676463 Nonlinear Static Analysis of Laminated Composite Hollow Beams with Super-Elliptic Cross-Sections
Authors: G. Akgun, I. Algul, H. Kurtaran
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In this paper geometrically nonlinear static behavior of laminated composite hollow super-elliptic beams is investigated using generalized differential quadrature method. Super-elliptic beam can have both oval and elliptic cross-sections by adjusting parameters in super-ellipse formulation (also known as Lamé curves). Equilibrium equations of super-elliptic beam are obtained using the virtual work principle. Geometric nonlinearity is taken into account using von-Kármán nonlinear strain-displacement relations. Spatial derivatives in strains are expressed with the generalized differential quadrature method. Transverse shear effect is considered through the first-order shear deformation theory. Static equilibrium equations are solved using Newton-Raphson method. Several composite super-elliptic beam problems are solved with the proposed method. Effects of layer orientations of composite material, boundary conditions, ovality and ellipticity on bending behavior are investigated.
Keywords: Generalized differential quadrature, geometric nonlinearity, laminated composite, super-elliptic cross-section.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1374