Search results for: surface erosion
1139 Modelling Forest Fire Risk in the Goaso Forest Area of Ghana: Remote Sensing and Geographic Information Systems Approach
Authors: Bernard Kumi-Boateng, Issaka Yakubu
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Forest fire, which is, an uncontrolled fire occurring in nature has become a major concern for the Forestry Commission of Ghana (FCG). The forest fires in Ghana usually result in massive destruction and take a long time for the firefighting crews to gain control over the situation. In order to assess the effect of forest fire at local scale, it is important to consider the role fire plays in vegetation composition, biodiversity, soil erosion, and the hydrological cycle. The occurrence, frequency and behaviour of forest fires vary over time and space, primarily as a result of the complicated influences of changes in land use, vegetation composition, fire suppression efforts, and other indigenous factors. One of the forest zones in Ghana with a high level of vegetation stress is the Goaso forest area. The area has experienced changes in its traditional land use such as hunting, charcoal production, inefficient logging practices and rural abandonment patterns. These factors which were identified as major causes of forest fire, have recently modified the incidence of fire in the Goaso area. In spite of the incidence of forest fires in the Goaso forest area, most of the forest services do not provide a cartographic representation of the burned areas. This has resulted in significant amount of information being required by the firefighting unit of the FCG to understand fire risk factors and its spatial effects. This study uses Remote Sensing and Geographic Information System techniques to develop a fire risk hazard model using the Goaso Forest Area (GFA) as a case study. From the results of the study, natural forest, agricultural lands and plantation cover types were identified as the major fuel contributing loads. However, water bodies, roads and settlements were identified as minor fuel contributing loads. Based on the major and minor fuel contributing loads, a forest fire risk hazard model with a reasonable accuracy has been developed for the GFA to assist decision making.
Keywords: Forest risk, GIS, remote sensing, Goaso.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19991138 Numerical Investigation of Dynamic Stall over a Wind Turbine Pitching Airfoil by Using OpenFOAM
Authors: Mahbod Seyednia, Shidvash Vakilipour, Mehran Masdari
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Computations for two-dimensional flow past a stationary and harmonically pitching wind turbine airfoil at a moderate value of Reynolds number (400000) are carried out by progressively increasing the angle of attack for stationary airfoil and at fixed pitching frequencies for rotary one. The incompressible Navier-Stokes equations in conjunction with Unsteady Reynolds Average Navier-Stokes (URANS) equations for turbulence modeling are solved by OpenFOAM package to investigate the aerodynamic phenomena occurred at stationary and pitching conditions on a NACA 6-series wind turbine airfoil. The aim of this study is to enhance the accuracy of numerical simulation in predicting the aerodynamic behavior of an oscillating airfoil in OpenFOAM. Hence, for turbulence modelling, k-ω-SST with low-Reynolds correction is employed to capture the unsteady phenomena occurred in stationary and oscillating motion of the airfoil. Using aerodynamic and pressure coefficients along with flow patterns, the unsteady aerodynamics at pre-, near-, and post-static stall regions are analyzed in harmonically pitching airfoil, and the results are validated with the corresponding experimental data possessed by the authors. The results indicate that implementing the mentioned turbulence model leads to accurate prediction of the angle of static stall for stationary airfoil and flow separation, dynamic stall phenomenon, and reattachment of the flow on the surface of airfoil for pitching one. Due to the geometry of the studied 6-series airfoil, the vortex on the upper surface of the airfoil during upstrokes is formed at the trailing edge. Therefore, the pattern flow obtained by our numerical simulations represents the formation and change of the trailing-edge vortex at near- and post-stall regions where this process determines the dynamic stall phenomenon.
Keywords: CFD, Moderate Reynolds number, OpenFOAM, pitching oscillation, unsteady aerodynamics, wind turbine.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15471137 New SUZ-4 Zeolite Membrane from Sol-Gel Technique
Authors: P. Worathanakul, P. Kongkachuichay
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A new SUZ-4 zeolite membrane with tetraethlyammonium hydroxide as the template was fabricated on mullite tube via hydrothermal sol-gel synthesis in a rotating autoclave reactor. The suitable synthesis condition was SiO2:Al2O3 ratio of 21.2 for 4 days at 155 °C crystallization under autogenous pressure. The obtained SUZ-4 possessed a high BET surface area of 396.4 m2/g, total pore volume at 2.611 cm3/g, and narrow pore size distribution with 97 nm mean diameter and 760 nm long of needle crystal shape. The SUZ-4 layer obtained from seeding crystallization was thicker than that of without seeds or in situ crystallization.Keywords: Membrane, seeding, sol-gel, SUZ-4 Zeolite.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19931136 Selective Wet-Etching of Amorphous/Crystallized Sb20se80 Thin Films
Authors: O. Shiman, V. Gerbreders, E. Sledevskis, A. Bulanovs, V.Pashkevich
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The selective wet-etching of amorphous and crystalline region of Sb20Se80 thin films was carried out using organic based solution e.g. amines. We report the development of an in situ real-time method to study the wet chemical etching process of thin films. Characterization of the structure and surface of films studied by X-ray diffraction, SEM and EBSD methods has been done and potential application suggested.Keywords: amorphous and crystalline phases, chalcogenide thinfilm, etching process
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19741135 Comparative Evaluation of Ice Adhesion Behavior
Authors: T. Strobl, D. Raps, M. Hornung
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In this study, the adhesion of ice to solid substrates with different surface properties is compared. Clear ice, similar to atmospheric in-flight icing encounters, is accreted on the different substrates under controlled conditions. The ice adhesion behavior is investigated by means of a dynamic vibration testing technique with an electromagnetic shaker initiating ice de-bonding in the interface between the substrate and the ice. The results of the experiments reveal that the affinity for ice accretion is significantly influenced by the water contact angle of the respective sample.Keywords: Contact angle, dynamic vibration measurement, ice adhesion, interfacial shear stress.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23461134 A Computational Model for Resolving Pronominal Anaphora in Turkish Using Hobbs- Naïve Algorithm
Authors: Pınar Tüfekçi, Yılmaz Kılıçaslan
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In this paper we present a computational model for pronominal anaphora resolution in Turkish. The model is based on Hobbs’ Naїve Algorithm [4, 5, 6], which exploits only the surface syntax of sentences in a given text.
Keywords: Anaphora Resolution, Pronoun Resolution, Syntax based Algorithms, Naїve Algorithm.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32381133 Method for Auto-Calibrate Projector and Color-Depth Systems for Spatial Augmented Reality Applications
Authors: R. Estrada, A. Henriquez, R. Becerra, C. Laguna
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Spatial Augmented Reality is a variation of Augmented Reality where the Head-Mounted Display is not required. This variation of Augmented Reality is useful in cases where the need for a Head-Mounted Display itself is a limitation. To achieve this, Spatial Augmented Reality techniques substitute the technological elements of Augmented Reality; the virtual world is projected onto a physical surface. To create an interactive spatial augmented experience, the application must be aware of the spatial relations that exist between its core elements. In this case, the core elements are referred to as a projection system and an input system, and the process to achieve this spatial awareness is called system calibration. The Spatial Augmented Reality system is considered calibrated if the projected virtual world scale is similar to the real-world scale, meaning that a virtual object will maintain its perceived dimensions when projected to the real world. Also, the input system is calibrated if the application knows the relative position of a point in the projection plane and the RGB-depth sensor origin point. Any kind of projection technology can be used, light-based projectors, close-range projectors, and screens, as long as it complies with the defined constraints; the method was tested on different configurations. The proposed procedure does not rely on a physical marker, minimizing the human intervention on the process. The tests are made using a Kinect V2 as an input sensor and several projection devices. In order to test the method, the constraints defined were applied to a variety of physical configurations; once the method was executed, some variables were obtained to measure the method performance. It was demonstrated that the method obtained can solve different arrangements, giving the user a wide range of setup possibilities.
Keywords: Color depth sensor, human computer interface, interactive surface, spatial augmented reality.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5991132 Wasting Human and Computer Resources
Authors: Mária Csernoch, Piroska Biró
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The legends about “user-friendly” and “easy-to-use” birotical tools (computer-related office tools) have been spreading and misleading end-users. This approach has led us to the extremely high number of incorrect documents, causing serious financial losses in the creating, modifying, and retrieving processes. Our research proved that there are at least two sources of this underachievement: (1) The lack of the definition of the correctly edited, formatted documents. Consequently, end-users do not know whether their methods and results are correct or not. They are not aware of their ignorance. They are so ignorant that their ignorance does not allow them to realize their lack of knowledge. (2) The end-users’ problem solving methods. We have found that in non-traditional programming environments end-users apply, almost exclusively, surface approach metacognitive methods to carry out their computer related activities, which are proved less effective than deep approach methods. Based on these findings we have developed deep approach methods which are based on and adapted from traditional programming languages. In this study, we focus on the most popular type of birotical documents, the text based documents. We have provided the definition of the correctly edited text, and based on this definition, adapted the debugging method known in programming. According to the method, before the realization of text editing, a thorough debugging of already existing texts and the categorization of errors are carried out. With this method in advance to real text editing users learn the requirements of text based documents and also of the correctly formatted text. The method has been proved much more effective than the previously applied surface approach methods. The advantages of the method are that the real text handling requires much less human and computer sources than clicking aimlessly in the GUI (Graphical User Interface), and the data retrieval is much more effective than from error-prone documents.
Keywords: Deep approach metacognitive methods, error-prone birotical documents, financial losses, human and computer resources.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19111131 Bee Parameter Determination via Weighted Centriod Modified Simplex and Constrained Response Surface Optimisation Methods
Authors: P. Luangpaiboon
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Various intelligences and inspirations have been adopted into the iterative searching process called as meta-heuristics. They intelligently perform the exploration and exploitation in the solution domain space aiming to efficiently seek near optimal solutions. In this work, the bee algorithm, inspired by the natural foraging behaviour of honey bees, was adapted to find the near optimal solutions of the transportation management system, dynamic multi-zone dispatching. This problem prepares for an uncertainty and changing customers- demand. In striving to remain competitive, transportation system should therefore be flexible in order to cope with the changes of customers- demand in terms of in-bound and outbound goods and technological innovations. To remain higher service level but lower cost management via the minimal imbalance scenario, the rearrangement penalty of the area, in each zone, including time periods are also included. However, the performance of the algorithm depends on the appropriate parameters- setting and need to be determined and analysed before its implementation. BEE parameters are determined through the linear constrained response surface optimisation or LCRSOM and weighted centroid modified simplex methods or WCMSM. Experimental results were analysed in terms of best solutions found so far, mean and standard deviation on the imbalance values including the convergence of the solutions obtained. It was found that the results obtained from the LCRSOM were better than those using the WCMSM. However, the average execution time of experimental run using the LCRSOM was longer than those using the WCMSM. Finally a recommendation of proper level settings of BEE parameters for some selected problem sizes is given as a guideline for future applications.Keywords: Meta-heuristic, Bee Algorithm, Dynamic Multi-Zone Dispatching, Linear Constrained Response SurfaceOptimisation Method, Weighted Centroid Modified Simplex Method
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13731130 Effect of Soil Tillage System upon the Soil Properties, Weed Control, Quality and Quantity Yield in Some Arable Crops
Authors: T Rusu, P I Moraru, I Bogdan, A I Pop, M L Sopterean
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The paper presents the influence of the conventional ploughing tillage technology in comparison with the minimum tillage, upon the soil properties, weed control and yield in the case of maize (Zea mays L.), soya-bean (Glycine hispida L.) and winter wheat (Triticum aestivum L.) in a three years crop rotation. A research has been conducted at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Romania. The use of minimum soil tillage systems within a three years rotation: maize, soya-bean, wheat favorites the rise of the aggregates hydro stability with 5.6-7.5% on a 0-20 cm depth and 5-11% on 20-30 cm depth. The minimum soil tillage systems – paraplow, chisel or rotary grape – are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. The soil tillage system influences the productivity elements of cultivated species and finally the productions thus obtained. Thus, related to conventional working system, the productions registered in minimum tillage working represented 89- 97% in maize, 103-112% in soya-bean, 93-99% in winter-wheat. The results of investigations showed that the yield is a conclusion soil tillage systems influence on soil properties, plant density assurance and on weed control. Under minimum tillage systems in the case of winter weat as an option for replacing classic ploughing, the best results in terms of quality indices were obtained from version worked with paraplow, followed by rotary harrow and chisel. At variants worked with paraplow were obtained quality indices close to those of the variant worked with plow, and protein and gluten content was even higher. At Ariesan variety, highest protein content, 12.50% and gluten, 28.6% was obtained for the variant paraplow.Keywords: Minimum tillage, soil properties, yields quality.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19191129 Genetic Algorithms in Hot Steel Rolling for Scale Defect Prediction
Authors: Jarno Haapamäki, Juha Röning
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Scale defects are common surface defects in hot steel rolling. The modelling of such defects is problematic and their causes are not straightforward. In this study, we investigated genetic algorithms in search for a mathematical solution to scale formation. For this research, a high-dimensional data set from hot steel rolling process was gathered. The synchronisation of the variables as well as the allocation of the measurements made on the steel strip were solved before the modelling phase.
Keywords: Genetic algorithms, hot strip rolling, knowledge discovery, modeling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 33061128 Influence of Temperature and Precipitation Changes on Desertification
Authors: Kukuri Tavartkiladze, Nana Bolashvili
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The purpose of this paper was separation and study of the part of structure regime, which directly affects the process of desertification. A simple scheme was prepared for the assessment of desertification process; surface air temperature and precipitation for the years of 1936-2009 were analyzed. The map of distribution of the Desertification Contributing Coefficient in the territory of Georgia was compiled. The simple scheme for identification of the intensity of the desertification contributing process has been developed and the illustrative example of its practical application for the territory of Georgia has been conducted.
Keywords: Climate change, aridity, desertification, precipitation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9721127 Field Trial of Resin-Based Composite Materials for the Treatment of Surface Collapses Associated with Former Shallow Coal Mining
Authors: Philip T. Broughton, Mark P. Bettney, Isla L. Smail
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Effective treatment of ground instability is essential when managing the impacts associated with historic mining. A field trial was undertaken by the Coal Authority to investigate the geotechnical performance and potential use of composite materials comprising resin and fill or stone to safely treat surface collapses, such as crown-holes, associated with shallow mining. Test pits were loosely filled with various granular fill materials. The fill material was injected with commercially available silicate and polyurethane resin foam products. In situ and laboratory testing was undertaken to assess the geotechnical properties of the resultant composite materials. The test pits were subsequently excavated to assess resin permeation. Drilling and resin injection was easiest through clean limestone fill materials. Recycled building waste fill material proved difficult to inject with resin; this material is thus considered unsuitable for use in resin composites. Incomplete resin permeation in several of the test pits created irregular ‘blocks’ of composite. Injected resin foams significantly improve the stiffness and resistance (strength) of the un-compacted fill material. The stiffness of the treated fill material appears to be a function of the stone particle size, its associated compaction characteristics (under loose tipping) and the proportion of resin foam matrix. The type of fill material is more critical than the type of resin to the geotechnical properties of the composite materials. Resin composites can effectively support typical design imposed loads. Compared to other traditional treatment options, such as cement grouting, the use of resin composites is potentially less disruptive, particularly for sites with limited access, and thus likely to achieve significant reinstatement cost savings. The use of resin composites is considered a suitable option for the future treatment of shallow mining collapses.
Keywords: Composite material, ground improvement, mining legacy, resin.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15411126 Synthesis and Characterization of Surface Functionalized Nanobiocomposite by Nano Hydroxyapatite
Authors: M. Meskinfam , M. S. Sadjadi , H. Jazdarreh
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In this study, synthesis of biomemitic patterned nano hydroxyapatite-starch biocomposites using different concentration of starch to evaluate effect of polymer alteration on biocomposites structural properties has been reported. Formation of hydroxyapatite nano particles was confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Size and morphology of the samples were characterized using scanning and transmission electron microscopy (SEM and TEM). It seems that by increasing starch content, the more active site of polymer (oxygen atoms) can be provided for interaction with Ca2+ followed by phosphate and hydroxyl group.Keywords: Biocomposite, Biomimetic, Nano hydroxyapatite, Starch
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23861125 Solar Energy Collection using a Double-layer Roof
Authors: S. Kong Wang
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The purpose of this study is to investigate the efficiency of a double-layer roof in collecting solar energy as an application to the areas such as raising high-end temperature of organic Rankine cycle (ORC). The by-product of the solar roof is to reduce building air-conditioning loads. The experimental apparatus are arranged to evaluate the effects of the solar roof in absorbing solar energy. The flow channel is basically formed by an aluminum plate on top of a plywood plate. The geometric configurations in which the effects of absorbing energy is analyzed include: a bare uncovered aluminum plate, a glass-covered aluminum plate, a glass-covered/black-painted aluminum plate, a plate with variable lengths, a flow channel with stuffed material (in an attempt on enhancement of heat conduction), and a flow channel with variable slanted angles. The experimental results show that the efficiency of energy collection varies from 0.6 % to 11 % for the geometric configurations mentioned above. An additional study is carried out using CFD simulation to investigate the effects of fins on the aluminum plate. It shows that due to vastly enhanced heat conduction, the efficiency can reach ~23 % if 50 fins are installed on the aluminum plate. The study shows that a double-layer roof can efficiently absorb solar energy and substantially reduce building air-conditioning loads. On the high end of an organic Rankine cycle, a solar pond is used to replace the warm surface water of the sea as OTEC (ocean thermal energy conversion) is the driving energy for the ORC. The energy collected from the double-layered solar roof can be pumped into the pond and raise the pond temperature as the pond surface area is equivalently increased by nearly one-fourth of the total area of the double-layer solar roof. The effect of raising solar pond temperature is especially prominent if the double-layer solar roofs are installed in a community area.Keywords: solar energy collection, double-layer solar roof, energy conservation, ORC, OTEC
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23341124 Development of a Robot Assisted Centrifugal Casting Machine for Manufacturing Multi-Layer Journal Bearing and High-Tech Machine Components
Authors: Mohammad Syed Ali Molla, Mohammed Azim, Mohammad Esharuzzaman
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Centrifugal-casting machine is used in manufacturing special machine components like multi-layer journal bearing used in all internal combustion engine, steam, gas turbine and air craft turboengine where isotropic properties and high precisions are desired. Moreover, this machine can be used in manufacturing thin wall hightech machine components like cylinder liners and piston rings of IC engine and other machine parts like sleeves, and bushes. Heavy-duty machine component like railway wheel can also be prepared by centrifugal casting. A lot of technological developments are required in casting process for production of good casted machine body and machine parts. Usually defects like blowholes, surface roughness, chilled surface etc. are found in sand casted machine parts. But these can be removed by centrifugal casting machine using rotating metallic die. Moreover, die rotation, its temperature control, and good pouring practice can contribute to the quality of casting because of the fact that the soundness of a casting in large part depends upon how the metal enters into the mold or dies and solidifies. Poor pouring practice leads to variety of casting defects such as temperature loss, low quality casting, excessive turbulence, over pouring etc. Besides these, handling of molten metal is very unsecured and dangerous for the workers. In order to get rid of all these problems, the need of an automatic pouring device arises. In this research work, a robot assisted pouring device and a centrifugal casting machine are designed, developed constructed and tested experimentally which are found to work satisfactorily. The robot assisted pouring device is further modified and developed for using it in actual metal casting process. Lot of settings and tests are required to control the system and ultimately it can be used in automation of centrifugal casting machine to produce high-tech machine parts with desired precision.Keywords: Casting, cylinder liners, journal bearing, robot.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21641123 Synthesis and Study the Effect of HNTs on PVA/Chitosan Composite Material
Authors: Malek Ali
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Composites materials of Poly (vinyl alcohol) (PVA)/Chitosan (CS) have been synthesized and characterized successfully. HNTs have been added to composites to enhance the mechanical and degradation properties by hydrogen bonding interactions, compatibility, and chemical crosslink between HNTs and PVA. PVA/CS/HNTs composites prepared with different concentration ratio. SEM micrographs of composites surface showed that more agglomeration with more chitosan ratio. Mechanical and degradation properties were characterized and the result indicates that Mechanical and degradation of 80%PVA/5%Chitosan/15%HNTs higher than the others PVA/CS/HNTs composites.
Keywords: PVA/Chitosan, Composites, PVA/CS/HNTs, HNTs.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16791122 Oily Sludge Bioremediation Pilot Plant Project, Nigeria
Authors: Ime R. Udotong, Justina I. R. Udotong, Ofonime U. M. John
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Brass terminal, one of the several crude oil and petroleum products storage/handling facilities in the Niger Delta was built in the 1980s. Activities at this site, over the years, released crude oil into this 3 m-deep, 1500 m-long canal lying adjacent to the terminal with oil floating on it and its sediment heavily polluted. To ensure effective clean-up, three major activities were planned: site characterization, bioremediation pilot plant construction and testing and full-scale bioremediation of contaminated sediment / bank soil by land farming. The canal was delineated into 12 lots and each characterized, with reference to the floating oily phase, contaminated sediment and canal bank soil. As a result of site characterization, a pilot plant for on-site bioremediation was designed and a treatment basin constructed for carrying out pilot bioremediation test. Following a designed sampling protocol, samples from this pilot plant were collected for analysis at two laboratories as a quality assurance / quality control check. Results showed that Brass Canal upstream is contaminated with dark, thick and viscous oily film with characteristic hydrocarbon smell while downstream, thin oily film interspersed with water was observed. Sediments were observed to be dark with mixture of brownish sandy soil with TPH ranging from 17,800 mg/kg in Lot 1 to 88,500 mg/kg in Lot 12 samples. Brass Canal bank soil was observed to be sandy from ground surface to 3m, below ground surface (bgs) it was silty-sandy and brownish while subsurface soil (4-10m bgs) was sandy-clayey and whitish/grayish with typical hydrocarbon smell. Preliminary results obtained so far have been very promising but were proprietary. This project is considered, to the best of technical literature knowledge, the first large-scale on-site bioremediation project in the Niger Delta region, Nigeria.Keywords: Bioremediation, Contaminated sediment, Land farming, Oily sludge, Oil Terminal.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20601121 Thermoelectric Generators as Alternative Source for Electric Power
Authors: L. C. Ding, Bradley. G. Orr, K. Rahaoui, S. Truza, A. Date, A. Akbarzadeh
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The research on thermoelectric has been a blooming field of research for the latest decade, owing to large amount of heat source available to be harvested, being eco-friendly and static in operation. This paper provides the performance of thermoelectric generator (TEG) with bulk material of bismuth telluride, Bi2Te3. Later, the performance of the TEGs is evaluated by considering attaching the TEGs on a plastic (polyethylene sheet) in contrast to the common method of attaching the TEGs on the metal surface.
Keywords: Electric power, heat transfer, renewable energy, thermoelectric generator.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17691120 Industrial Development, Environment And Occupational Problems: The Case Of Iran
Authors: Ghaffari, H., Changi Ashtiani, A., Younessi, A.
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There are three distinct stages in the evolution of economic thought, namely: 1. in the first stage, the major concern was to accelerate economic growth with increased availability of material goods, especially in developing economies with very low living standards, because poverty eradication meant faster economic growth. 2. in the second stage, economists made distinction between growth and development. Development was seen as going beyond economic growth, and bringing certain changes in the structure of the economy with more equitable distribution of the benefits of growth, with the growth coming automatic and sustained. 3. the third stage is now reached. Our concern is now with “sustainable development", that is, development not only for the present but also of the future. Thus the focus changed from “sustained growth" to “sustained development". Sustained development brings to the fore the long term relationship between the ecology and economic development. Since the creation of UNEP in 1972 it has worked for development without destruction for environmentally sound and sustained development. It was realised that the environment cannot be viewed in a vaccum, it is not separate from development, nor is it competing. It suggested for the integration of the environment with development whereby ecological factors enter development planning, socio-economic policies, cost-benefit analysis, trade, technology transfer, waste management, educational and other specific areas. Industrialisation has contributed to the growth of economy of several countries. It has improved the standards of living of its people and provided benefits to the society. It has also created in the process great environmental problems like climate change, forest destruction and denudation, soil erosion and desertification etc. On the other hand, industry has provided jobs and improved the prospects of wealth for the industrialists. The working class communities had to simply put up with the high levels of pollution in order to keep up their jobs and also to save their income. There are many roots of the environmental problem. They may be political, economic, cultural and technological conditions of the modern society. The experts concede that industrial growth lies somewhere close to the heart of the matter. Therefore, the objective of this paper is not to document all roots of an environmental crisis but rather to discuss the effects of industrial growth and development. We have come to the conclusion that although public intervention is often unnecessary to ensure that perfectly competitive markets will function in society-s best interests, such intervention is necessary when firms or consumers pollute.Keywords: Development, Environment, Industrial Development, Iran, Occupational problems, Pollution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16561119 Annealing of the Contact between Graphene and Metal: Electrical and Raman Study
Authors: A. Sakavičius, A. Lukša, V. Nargelienė, V. Bukauskas, G. Astromskas, A. Šetkus
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We investigate the influence of annealing on the properties of a contact between graphene and metal (Au and Ni), using circular transmission line model (CTLM) contact geometry. Kelvin probe force microscopy (KPFM) and Raman spectroscopy are applied for characterization of the surface and interface properties. Annealing causes a decrease of the metal-graphene contact resistance for both Ni and Au.Keywords: Graphene, Kelvin force probe microscopy, Raman spectroscopy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13671118 Mesoporous Material Nanofibers by Electrospinning
Authors: Sh. Sohrabnezhad, A. Jafarzadeh
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In this paper, MCM-41 mesoporous material nanofibers were synthesized by an electrospinning technique. The nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), and nitrogen adsorption–desorption measurement. Tetraethyl orthosilicate (TEOS) and polyvinyl alcohol (PVA) were used as a silica source and fiber forming source, respectively. TEM and SEM images showed synthesis of MCM-41 nanofibers with a diameter of 200 nm. The pore diameter and surface area of calcined MCM-41 nanofibers was 2.2 nm and 970 m2/g, respectively. The morphology of the MCM-41 nanofibers depended on spinning voltages.Keywords: Electrospinning, electron microscopy, fiber technology, porous materials, X-ray techniques.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18201117 Determination of Vitamin C (Ascorbic Acid) in Orange Juices Product
Authors: Wanida Wonsawat
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This research describes a voltammetric approach to determine amounts of vitamin C (Ascorbic acid) in orange juice sample, using three screen printed electrode. The anodic currents of vitamin C were proportional to vitamin C concentration in the range of 0 – 10.0 mM with the limit of detection of 1.36 mM. The method was successfully employed with 2 µL of the working solution dropped on the electrode surface. The proposed method was applied for the analysis of vitamin C in packed orange juice without sample purification or complexion of sample preparation step.
Keywords: Ascorbic acid, Vitamin C, Juice, Voltammetry
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 84811116 Catalytic Cracking of Butene to Propylene over Modified HZSM-5 Zeolites
Authors: Jianwen Li, Hongfang Ma, Haitao Zhang, Qiwen Sun, Weiyong Ying
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Catalytic cracking of butene to propylene was carried out in a continuous-flow fixed-bed reactor over HZSM-5 catalysts modified by nickel and phosphorus. The structure and acidity of catalysts were measured by N2 adsorption, NH3-TPD and XPS. The results revealed that surface area and strong acid sites both decreased with increasing phosphorus loadings. The increment of phosphorus loadings reduced the butene conversion but enhanced the propylene selectivity and catalyst stability.
Keywords: Butene, catalytic cracking, HZSM-5, modification.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 31841115 Analysis of Structural and Photocatalytical Properties of Anatase, Rutile and Mixed Phase TiO2 Films Deposited by Pulsed-Direct Current and Radio Frequency Magnetron Co-Sputtering
Authors: S. Varnagiris, M. Urbonavicius, S. Tuckute, M. Lelis, K. Bockute
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Amongst many water purification techniques, TiO2 photocatalysis is recognized as one of the most promising sustainable methods. It is known that for photocatalytical applications anatase is the most suitable TiO2 phase, however heterojunction of anatase/rutile phases could improve the photocatalytical activity of TiO2 even further. Despite the relative simplicity of TiO2 different synthesis methods lead to the highly dispersed crystal phases and photocatalytic activity of the corresponding samples. Accordingly, suggestions and investigations of various innovative methods of TiO2 synthesis are still needed. In this work structural and photocatalytical properties of TiO2 films deposited by the unconventional method of simultaneous co-sputtering from two magnetrons powered by pulsed-Direct Current (pDC) and Radio Frequency (RF) power sources with negative bias voltage have been studied. More specifically, TiO2 film thickness, microstructure, surface roughness, crystal structure, optical transmittance and photocatalytical properties were investigated by profilometer, scanning electron microscope, atomic force microscope, X-ray diffractometer and UV-Vis spectrophotometer respectively. The proposed unconventional two magnetron co-sputtering based TiO2 film formation method showed very promising results for crystalline TiO2 film formation while keeping process temperatures below 100 °C. XRD analysis revealed that by using proper combination of power source type and bias voltage various TiO2 phases (amorphous, anatase, rutile or their mixture) can be synthesized selectively. Moreover, strong dependency between power source type and surface roughness, as well as between the bias voltage and band gap value of TiO2 films was observed. Interestingly, TiO2 films deposited by two magnetron co-sputtering without bias voltage had one of the highest band gap values between the investigated films but its photocatalytic activity was superior compared to all other samples. It is suggested that this is due to the dominating nanocrystalline anatase phase with various exposed surfaces including photocatalytically the most active {001}.
Keywords: Films, magnetron co-sputtering, photocatalysis, TiO2.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6511114 Microwave-Assisted Alginate Extraction from Portuguese Saccorhiza polyschides – Influence of Acid Pretreatment
Authors: Mário Silva, Filipa Gomes, Filipa Oliveira, Simone Morais, Cristina Delerue-Matos
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Brown seaweeds are abundant in Portuguese coastline and represent an almost unexploited marine economic resource. One of the most common species, easily available for harvesting in the northwest coast, is Saccorhiza polyschides grows in the lowest shore and costal rocky reefs. It is almost exclusively used by local farmers as natural fertilizer, but contains a substantial amount of valuable compounds, particularly alginates, natural biopolymers of high interest for many industrial applications. Alginates are natural polysaccharides present in cell walls of brown seaweed, highly biocompatible, with particular properties that make them of high interest for the food, biotechnology, cosmetics and pharmaceutical industries. Conventional extraction processes are based on thermal treatment. They are lengthy and consume high amounts of energy and solvents. In recent years, microwave-assisted extraction (MAE) has shown enormous potential to overcome major drawbacks that outcome from conventional plant material extraction (thermal and/or solvent based) techniques, being also successfully applied to the extraction of agar, fucoidans and alginates. In the present study, acid pretreatment of brown seaweed Saccorhiza polyschides for subsequent microwave-assisted extraction (MAE) of alginate was optimized. Seaweeds were collected in Northwest Portuguese coastal waters of the Atlantic Ocean between May and August, 2014. Experimental design was used to assess the effect of temperature and acid pretreatment time in alginate extraction. Response surface methodology allowed the determination of the optimum MAE conditions: 40 mL of HCl 0.1 M per g of dried seaweed with constant stirring at 20ºC during 14h. Optimal acid pretreatment conditions have enhanced significantly MAE of alginates from Saccorhiza polyschides, thus contributing for the development of a viable, more environmental friendly alternative to conventional processes.
Keywords: Acid pretreatment, Alginate, Brown seaweed, Microwave-assisted extraction, Response surface methodology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 33451113 Numerical Solution of Steady Magnetohydrodynamic Boundary Layer Flow Due to Gyrotactic Microorganism for Williamson Nanofluid over Stretched Surface in the Presence of Exponential Internal Heat Generation
Authors: M. A. Talha, M. Osman Gani, M. Ferdows
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This paper focuses on the study of two dimensional magnetohydrodynamic (MHD) steady incompressible viscous Williamson nanofluid with exponential internal heat generation containing gyrotactic microorganism over a stretching sheet. The governing equations and auxiliary conditions are reduced to a set of non-linear coupled differential equations with the appropriate boundary conditions using similarity transformation. The transformed equations are solved numerically through spectral relaxation method. The influences of various parameters such as Williamson parameter γ, power constant λ, Prandtl number Pr, magnetic field parameter M, Peclet number Pe, Lewis number Le, Bioconvection Lewis number Lb, Brownian motion parameter Nb, thermophoresis parameter Nt, and bioconvection constant σ are studied to obtain the momentum, heat, mass and microorganism distributions. Moment, heat, mass and gyrotactic microorganism profiles are explored through graphs and tables. We computed the heat transfer rate, mass flux rate and the density number of the motile microorganism near the surface. Our numerical results are in better agreement in comparison with existing calculations. The Residual error of our obtained solutions is determined in order to see the convergence rate against iteration. Faster convergence is achieved when internal heat generation is absent. The effect of magnetic parameter M decreases the momentum boundary layer thickness but increases the thermal boundary layer thickness. It is apparent that bioconvection Lewis number and bioconvection parameter has a pronounced effect on microorganism boundary. Increasing brownian motion parameter and Lewis number decreases the thermal boundary layer. Furthermore, magnetic field parameter and thermophoresis parameter has an induced effect on concentration profiles.
Keywords: Convection flow, internal heat generation, similarity, spectral method, numerical analysis, Williamson nanofluid.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9711112 Approximate Solution of Some Mixed Boundary Value Problems of the Generalized Theory of Couple-Stress Thermo-Elasticity
Authors: M. Chumburidze, D. Lekveishvili
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We have considered the harmonic oscillations and general dynamic (pseudo oscillations) systems of theory generalized Green-Lindsay of couple-stress thermo-elasticity for isotropic, homogeneous elastic media. Approximate solution of some mixed boundary value problems for finite domain, bounded by the some closed surface are constructed.
Keywords: The couple-stress thermo-elasticity, boundary value problems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20311111 A Simplified Distribution for Nonlinear Seas
Authors: M. A. Tayfun, M. A. Alkhalidi
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The exact theoretical expression describing the probability distribution of nonlinear sea-surface elevations derived from the second-order narrowband model has a cumbersome form that requires numerical computations, not well-disposed to theoretical or practical applications. Here, the same narrowband model is reexamined to develop a simpler closed-form approximation suitable for theoretical and practical applications. The salient features of the approximate form are explored, and its relative validity is verified with comparisons to other readily available approximations, and oceanic data.
Keywords: Ocean waves, probability distributions, second-order nonlinearities, skewness coefficient, wave steepness.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20961110 Sericin Film: Influence of Concentration on its Physical Properties
Authors: N. Namviriyachote, N. Bang, P. Aramwit
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Silk sericin (SS) is a glue-like protein from silkworm cocoon. With its outstanding moisturization and activation collagen synthesis properties, silk protein is applied for wound healing. Since wound dressing in film preparation can facilitate patients- convenience and reduce risk of wound contraction, SS and polyvinyl alcohol (PVA) films were prepared with various concentrations of SS. Their physical properties such as surface density, light transmission, protein dissolution and tensile modulus were investigated. The results presented that 3% SS with 2% PVA is the best ingredient for SS film forming.Keywords: Sericin, silk protein, film, wound healing.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2130