Search results for: Field effect transistor.
5954 The Smoke Suppression Effect of Copper Oxideon the Epoxy Resin/Intumescent Flame Retardant/Titanate Couple Agent System
Authors: Zhiping Wu, Meiqin Chen, Haikuan Yang, Yunchu Hu
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Fire disaster is the major factor to endanger the public and environmental safety. People lost their life during fire disaster mainly be attributed to the dense smoke and toxic gas under combustion, which hinder the escape of people and the rescue of firefighters under fire disaster. The smoke suppression effect of several transitional metals oxide on the epoxy resin treated with intumescent flame retardant and titanate couple agent (EP/IFR/Titanate) system have been investigated. The results showed manganese dioxide has great effect on reducing the smoke density rate (SDR) of EP/IFR/Titanate system; however it has little effect to reduce the maximum smoke density (MSD) of EP/IFR/Titanate system. Copper oxide can decrease the maximum smoke density (MSD) and smoke density rate of EP/IFR/Titanate system substantially. The MSD and SDR of EP/IFR/Titanate system can reduce 20.3% and 39.1% respectively when 2% of copper oxide is introduced.Keywords: copper oxide, epoxy resin, intumescent flameretardant, smoke suppression.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26955953 Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops: Statistical Evaluation of the Potential Herbicide Savings
Authors: Morten Stigaard Laursen, Rasmus Nyholm Jørgensen, Henrik Skov Midtiby, Anders Krogh Mortensen, Sanmohan Baby
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This work contributes a statistical model and simulation framework yielding the best estimate possible for the potential herbicide reduction when using the MoDiCoVi algorithm all the while requiring a efficacy comparable to conventional spraying. In June 2013 a maize field located in Denmark were seeded. The field was divided into parcels which was assigned to one of two main groups: 1) Control, consisting of subgroups of no spray and full dose spraty; 2) MoDiCoVi algorithm subdivided into five different leaf cover thresholds for spray activation. In addition approximately 25% of the parcels were seeded with additional weeds perpendicular to the maize rows. In total 299 parcels were randomly assigned with the 28 different treatment combinations. In the statistical analysis, bootstrapping was used for balancing the number of replicates. The achieved potential herbicide savings was found to be 70% to 95% depending on the initial weed coverage. However additional field trials covering more seasons and locations are needed to verify the generalisation of these results. There is a potential for further herbicide savings as the time interval between the first and second spraying session was not long enough for the weeds to turn yellow, instead they only stagnated in growth.Keywords: Weed crop discrimination, macrosprayer, herbicide reduction, site-specific, sprayer-boom.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10495952 Improving Cache Memory Utilization
Authors: Sami I. Serhan, Hamed M. Abdel-Haq
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In this paper, an efficient technique is proposed to manage the cache memory. The proposed technique introduces some modifications on the well-known set associative mapping technique. This modification requires a little alteration in the structure of the cache memory and on the way by which it can be referenced. The proposed alteration leads to increase the set size virtually and consequently to improve the performance and the utilization of the cache memory. The current mapping techniques have accomplished good results. In fact, there are still different cases in which cache memory lines are left empty and not used, whereas two or more processes overwrite the lines of each other, instead of using those empty lines. The proposed algorithm aims at finding an efficient way to deal with such problem.
Keywords: Modified Set Associative Mapping, Locality of Reference, Miss Ratio, Hit Ratio, Cache Memory, Clustered Behavior, Index Address, Tag Field, Status Field, and Complement of Index Address.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19275951 Effect of Oxygen and Micro-Cracking on the Flotation of Low Grade Nickel Sulphide Ore
Authors: Edison Muzenda, Ayo S Afolabi
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This study investigated the effect of oxygen and micro-cracking on the flotation of low grade nickel sulphide ore. The ore treated contained serpentine minerals which have a history of being difficult to process efficiently. The use of oxygen as a bubbling gas has been noted to be effective because it increases the pulp potential. The desired effect of micro cracking the ore is that the nickel sulphide minerals will become activated and this activation will render these minerals more susceptible to react with potassium amyl xanthate collectors, resulting in a higher recovery of nickel and hinder the recovery of other undesired minerals contained in the ore. Higher nickel recoveries were obtained when pure oxygen was used as a bubbling gas rather than the conventional air. Microwave cracking favored the recovery of nickel.Keywords: Flotation, Conventional air, Oven micro-cracking, Recovery.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21985950 The Effect of Computer-Mediated vs. Face-to-Face Instruction on L2 Pragmatics: A Meta-Analysis
Authors: Marziyeh Yousefi, Hossein Nassaji
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This paper reports the results of a meta-analysis of studies on the effects of instruction mode on learning second language pragmatics during the last decade (from 2006 to 2016). After establishing related inclusion/ exclusion criteria, 39 published studies were retrieved and included in the present meta-analysis. Studies were later coded for face-to-face and computer-assisted mode of instruction. Statistical procedures were applied to obtain effect sizes. It was found that Computer-Assisted-Language-Learning studies generated larger effects than Face-to-Face instruction.Keywords: Meta-analysis, effect size, pragmatics, computer-assisted language learnin, face-to-face instruction, comprehensive meta-analysis software.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7825949 Application of Natural Clay to Formulate Nontraditional Completion Fluid that Triples Oil Productivity
Authors: Munawar Khalil, Badrul Mohamed Jan, Abdul Aziz Abdul Raman
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In the last decades, the problem of perforation damage has been considered as the major factor for the reduction of oil productivity. Underbalance perforation is considered as one of the best means to minimize or overcome this problem. By maintaining wellbore pressure lower than formation pressure, perforation damage could be minimize or eliminated. This can be achieved by the use of nontraditional lightweight completion fluid. This paper presents the effect of natural clay in formulating nontraditional completion fluid to ensure successful perforation job and increase of production rate. Natural clay is used as homogenizing agent to create a stable and non-damaging low-density completion fluid. Results indicate that the addition of natural clay dramatically increase the stability of the final fluids. In addition, field test has shown that the application of nontraditional completion fluid increases oil production by three folds.Keywords: Completion fluid, underbalance, clay, oil production.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13935948 Effect of Inclusions on the Shape and Size of Crack Tip Plastic Zones by Element Free Galerkin Method
Authors: A. Jameel, G. A. Harmain, Y. Anand, J. H. Masoodi, F. A. Najar
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The present study investigates the effect of inclusions on the shape and size of crack tip plastic zones in engineering materials subjected to static loads by employing the element free Galerkin method (EFGM). The modeling of the discontinuities produced by cracks and inclusions becomes independent of the grid chosen for analysis. The standard displacement approximation is modified by adding additional enrichment functions, which introduce the effects of different discontinuities into the formulation. The level set method has been used to represent different discontinuities present in the domain. The effect of inclusions on the extent of crack tip plastic zones is investigated by solving some numerical problems by the EFGM.
Keywords: EFGM, stress intensity factors, crack tip plastic zones, inclusions.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8865947 Effect of Derating Factors on Photovoltaics under Climatic Conditions of Istanbul
Authors: Bihter Yerli, Mustafa K. Kaymak, Ercan İzgi, Ahmet Öztopal, Ahmet D. Şahin
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As known that efficiency of photovoltaic cells is not high as desired level. Efficiency of PVs could be improved by selecting convenient locations that have high solar irradiation, sunshine duration, mild temperature, low level air pollution and dust concentration. Additionally, some environmental parameters called derating factors effect to decrease PV efficiencies such as cloud, high temperature, aerosol optical depth, high dust concentration, shadow, snow, humidity etc. In this paper, all parameters that effect PV efficiency are considered in detail under climatic conditions of Istanbul. A 750 Wp PV system with measurement devices is constructed in Maslak campus of Istanbul Technical University.Keywords: Efficiency, Derating Factor, Istanbul, Photovoltaic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 44385946 Standalone Docking Station with Combined Charging Methods for Agricultural Mobile Robots
Authors: Leonor Varandas, Pedro D. Gaspar, Martim L. Aguiar
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One of the biggest concerns in the field of agriculture is around the energy efficiency of robots that will perform agriculture’s activity and their charging methods. In this paper, two different charging methods for agricultural standalone docking stations are shown that will take into account various variants as field size and its irregularities, work’s nature to which the robot will perform, deadlines that have to be respected, among others. Its features also are dependent on the orchard, season, battery type and its technical specifications and cost. First charging base method focuses on wireless charging, presenting more benefits for small field. The second charging base method relies on battery replacement being more suitable for large fields, thus avoiding the robot stop for recharge. Existing many methods to charge a battery, the CC CV was considered the most appropriate for either simplicity or effectiveness. The choice of the battery for agricultural purposes is if most importance. While the most common battery used is Li-ion battery, this study also discusses the use of graphene-based new type of batteries with 45% over capacity to the Li-ion one. A Battery Management Systems (BMS) is applied for battery balancing. All these approaches combined showed to be a promising method to improve a lot of technical agricultural work, not just in terms of plantation and harvesting but also about every technique to prevent harmful events like plagues and weeds or even to reduce crop time and cost.
Keywords: Agricultural mobile robot, charging base methods, battery replacement method, wireless charging method.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 8305945 Study of the Particle Size Effect on Bubble Rise Velocities in a Three-Phase Bubble Column
Authors: Weiling Li, Wenqi Zhong, Baosheng Jin, Rui Xiao, Yong Lu, Tingting He
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Experiments were performed in a three-phase bubble column to study variations of bubble rise velocities. The dynamic gas disengagement (DGD) technique and the fast response pressure transducers were utilized to investigate the bubble rise in the column. The superficial gas velocity of large bubbles and small bubbles, the rise velocities of larger and small bubble fractions were studied considering the effect of particle sizes. The results show that the superficial gas velocity associated with large bubbles linearly increase as superficial gas velocity increasing. Particle size has little effect on the both large and small bubble superficial gas velocities. The rise velocities of larger bubble fractions are larger than that of small bubble fractions, and it had different tendency at low and high superficial gas velocities when changing the particle sizes. The rise velocities of small bubble fractions increased and then had a decrease tendency when the particle size became greater.
Keywords: Bubble rise velocity, gas–liquid–solid, particle size effect, three–phase bubble column.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 34035944 Effect of Concrete Strength and Aspect Ratio on Strength and Ductility of Concrete Columns
Authors: Mohamed A. Shanan, Ashraf H. El-Zanaty, Kamal G. Metwally
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This paper presents the effect of concrete compressive strength and rectangularity ratio on strength and ductility of normal and high strength reinforced concrete columns confined with transverse steel under axial compressive loading. Nineteen normal strength concrete rectangular columns with different variables tested in this research were used to study the effect of concrete compressive strength and rectangularity ratio on strength and ductility of columns. The paper also presents a nonlinear finite element analysis for these specimens and another twenty high strength concrete square columns tested by other researchers using ANSYS 15 finite element software. The results indicate that the axial force – axial strain relationship obtained from the analytical model using ANSYS are in good agreement with the experimental data. The comparison shows that the ANSYS is capable of modeling and predicting the actual nonlinear behavior of confined normal and high-strength concrete columns under concentric loading. The maximum applied load and the maximum strain have also been confirmed to be satisfactory. Depending on this agreement between the experimental and analytical results, a parametric numerical study was conducted by ANSYS 15 to clarify and evaluate the effect of each variable on strength and ductility of the columns.
Keywords: ANSYS, concrete compressive strength effect, ductility, rectangularity ratio, strength.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18945943 Effect of Influent COD on Biological Ammonia Removal Efficiency
Authors: S. H. Mirhossaini, H. Godini, A. Jafari
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Biological Ammonia removal (nitrification), the oxidation of ammonia to nitrate catalyzed by bacteria, is a key part of global nitrogen cycling. In the first step of nitrification, chemolithoautotrophic ammonia oxidizer transform ammonia to nitrite, this subsequently oxidized to nitrate by nitrite oxidizing bacteria. This process can be affected by several factors. In this study the effect of influent COD on biological ammonia removal in a bench-scale biological reactor was investigated. Experiments were carried out using synthetic wastewater. The initial ammonium concentration was 25mgNH4 +-N L-1. The effect of COD between 247.55±1.8 and 601.08±3.24mgL-1 on biological ammonia removal was investigated by varying the COD loading supplied to reactor. From the results obtained in this study it could be concluded in the range of 247.55±1.8 to 351.35±2.05mgL-1, there is a direct relationship between amount of COD and ammonia removal. However more than 351.35±2.05 up to 601.08±3.24mgL-1 were found an indirect relationship between them.Keywords: Ammonia biological removal, Nitrification, InfluentCOD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 38815942 Effects of Irrigation Scheduling and Soil Management on Maize (Zea mays L.) Yield in Guinea Savannah Zone of Nigeria
Authors: I. Alhassan, A. M. Saddiq, A. G. Gashua, K. K. Gwio-Kura
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The main objective of any irrigation program is the development of an efficient water management system to sustain crop growth and development and avoid physiological water stress in the growing plants. Field experiment to evaluate the effects of some soil moisture conservation practices on yield and water use efficiency (WUE) of maize was carried out in three locations (i.e. Mubi and Yola in the northern Guinea Savannah and Ganye in the southern Guinea Savannah of Adamawa State, Nigeria) during the dry seasons of 2013 and 2014. The experiment consisted of three different irrigation levels (7, 10 and 12 day irrigation intervals), two levels of mulch (mulch and un-mulched) and two tillage practices (no tillage and minimum tillage) arranged in a randomized complete block design with split-split plot arrangement and replicated three times. The Blaney-Criddle method was used for measuring crop evapotranspiration. The results indicated that seven-day irrigation intervals and mulched treatment were found to have significant effect (P>0.05) on grain yield and water use efficiency in all the locations. The main effect of tillage was non-significant (P<0.05) on grain yield and WUE. The interaction effects of irrigation and mulch were significant (P>0.05) on grain yield and WUE at Mubi and Yola. Generally, higher grain yield and WUE were recorded on mulched and seven-day irrigation intervals, whereas lower values were recorded on un-mulched with 12-day irrigation intervals. Tillage exerts little influence on the yield and WUE. Results from Ganye were found to be generally higher than those recorded in Mubi and Yola; it also showed that an irrigation interval of 10 days with mulching could be adopted for the Ganye area, while seven days interval is more appropriate for Mubi and Yola.
Keywords: Irrigation, maize, mulching, tillage, guinea savannah.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10925941 Numerical Studies on Flow Field Characteristics of Cavity Based Scramjet Combustors
Authors: Rakesh Arasu, Sasitharan Ambicapathy, Sivaraj Ponnusamy, Mohanraj Murugesan, V. R. Sanal Kumar
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The flow field within the combustor of scramjet engine is very complex and poses a considerable challenge in the design and development of a supersonic combustor with an optimized geometry. In this paper comprehensive numerical studies on flow field characteristics of different cavity based scramjet combustors with transverse injection of hydrogen have been carried out for both non-reacting and reacting flows. The numerical studies have been carried out using a validated 2D unsteady, density based 1st-order implicit k-omega turbulence model with multi-component finite rate reacting species. The results show a wide variety of flow features resulting from the interactions between the injector flows, shock waves, boundary layers, and cavity flows. We conjectured that an optimized cavity is a good choice to stabilize the flame in the hypersonic flow, and it generates a recirculation zone in the scramjet combustor. We comprehended that the cavity based scramjet combustors having a bearing on the source of disturbance for the transverse jet oscillation, fuel/air mixing enhancement, and flameholding improvement. We concluded that cavity shape with backward facing step and 45o forward ramp is a good choice to get higher temperatures at the exit compared to other four models of scramjet combustors considered in this study.
Keywords: Flame holding, Hypersonic flow, Scramjet combustor, Supersonic combustor.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32245940 Applying Bowen’s Theory to Intern Supervision
Authors: Jeff A. Tysinger, Dawn P. Tysinger
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The aim of this paper is to theoretically apply Bowen’s understanding of triangulation and triads to school psychology intern supervision so that it can assist in the conceptualization of the dynamics of intern supervision and provide some key methods to address common issues. The school psychology internship is the capstone experience for the school psychologist in training. It involves three key participants whose relationships will determine the success of the internship. To understand the potential effect, Bowen’s family systems theory can be applied to the supervision relationship. He describes a way to resolve stress between two people by triangulating or binging in a third person. He applies this to a nuclear family, but school psychology intern supervision requires the marriage of an intern, field supervisor, and university supervisor; thus, setting all up for possible triangulation. The consequences of triangulation can apply to standards and requirements, direct supervision, and intern evaluation. Strategies from family systems theory to decrease the negative impact of supervision triangulation.Keywords: Family systems theory, intern supervision, triangulation, school psychology.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10135939 Liquid Temperature Effect on Sound Propagation in Polymeric Solution with Gas Bubbles
Authors: S. Levitsky
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Acoustic properties of polymeric liquids are high sensitive to free gas traces in the form of fine bubbles. Their presence is typical for such liquids because of chemical reactions, small wettability of solid boundaries, trapping of air in technological operations, etc. Liquid temperature influences essentially its rheological properties, which may have an impact on the bubble pulsations and sound propagation in the system. The target of the paper is modeling of the liquid temperature effect on single bubble dynamics and sound dispersion and attenuation in polymeric solution with spherical gas bubbles. The basic sources of attenuation (heat exchange between gas in microbubbles and surrounding liquid, rheological and acoustic losses) are taken into account. It is supposed that in the studied temperature range the interface mass transfer has a minor effect on bubble dynamics. The results of the study indicate that temperature raise yields enhancement of bubble pulsations and increase in sound attenuation in the near-resonance range and may have a strong impact on sound dispersion in the liquid-bubble mixture at frequencies close to the resonance frequency of bubbles.Keywords: Sound propagation, gas bubbles, temperature effect, polymeric liquid.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22755938 Design and Fabrication of an Array Microejector Driven by a Shear-Mode Piezoelectric Actuator
Authors: Chiang-Ho Cheng, Hong-Yih Cheng, An-Shik Yang, Tung-Hsun Hsu
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This paper reports a novel actuating design that uses the shear deformation of a piezoelectric actuator to deflect a bulge-diaphragm for driving an array microdroplet ejector. In essence, we employed a circular-shaped actuator poled radial direction with remnant polarization normal to the actuating electric field for inducing the piezoelectric shear effect. The array microdroplet ejector consists of a shear type piezoelectric actuator, a vibration plate, two chamber plates, two channel plates and a nozzle plate. The vibration, chamber and nozzle plate components are fabricated using nickel electroforming technology, whereas the channel plate is fabricated by etching of stainless steel. The diaphragm displacement was measured by the laser two-dimensional scanning vibrometer. The ejected droplets of the microejector were also observed via an optic visualization system.Keywords: Actuator, nozzle, microejector, piezoelectric.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20955937 Influence of Cavity Length on Forward-facing Cavity and Opposing Jet Combined Thermal Protection System Cooling Efficiency
Authors: Hai-bo Lu, Wei-qiang Liu
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A numerical study on the influence of forward-facing cavity length upon forward-facing cavity and opposing jet combined thermal protection system (TPS) cooling efficiency under hypersonic flow is conducted, by means of which the flow field parameters, heat flux distribution along the outer body surface are obtained. The numerical simulation results are validated by experiments and the cooling effect of the combined TPS with different cavity length is analyzed. The numerical results show that the combined configuration dose well in cooling the nose of the hypersonic vehicle. The deeper the cavity is, the weaker the heat flux is. The recirculation region plays a key role for the reduction of the aerodynamic heating.Keywords: Thermal protection, hypersonic vehicle, aerodynamic heating, forward-facing cavity, opposing jet
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17315936 Effect of Spray Stand-off on Elasticity Modulus of Thermally Sprayed Coatings
Authors: M.Jalali Azizpour, S.Norouzi, H.mohammadi Majd, M.M.Rabieh, D.Sajedipour, A. Jaderi
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The mechanical and tribological properties in WC-Co coatings are strongly affected by hardness and elasticity specifications. The results revealed the effect of spraying distance on microhardness and elasticity modulus of coatings. The metallurgical studies have been made on coated samples using optical microscopy, scanning electron microscopy (SEM).Keywords: Elasticity modulus, HVOF, Micro-indentation, Thermal spray, WC-Co
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16955935 International Service Learning 3.0: Using Technology to Improve Outcomes and Sustainability
Authors: Anthony Vandarakis
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Today’s International Service Learning practices require an update: modern technologies, fresh educational frameworks, and a new operating system to accountably prosper. This paper describes a model of International Service Learning (ISL), which combines current technological hardware, electronic platforms, and asynchronous communications that are grounded in inclusive pedagogy. This model builds on the work around collaborative field trip learning, extending the reach to international partnerships across continents. Mobile technology, 21st century skills and summit-basecamp modeling intersect to support novel forms of learning that tread lightly on fragile natural ecosystems, affirm local reciprocal partnership in projects, and protect traveling participants from common yet avoidable cultural pitfalls.Keywords: International Service Learning, ISL, field experiences, mobile technology, ‘out there in here’, summit basecamp pedagogy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5625934 Value from Environmental and Cultural Perspectives or Two Sides of the Same Coin
Authors: Vilém Pařil, Dominika Tóthová
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This paper discusses the value theory in cultural heritage and the value theory in environmental economics. Two economic views of the value theory are compared, within the field of cultural heritage maintenance and within the field of the environment. The main aims are to find common features in these two differently structured theories under the layer of differently defined terms as well as really differing features of these two approaches; to clear the confusion which stems from different terminology as in fact these terms capture the same aspects of reality; and to show possible inspiration these two perspectives can offer one another. Another aim is to present these two value systems in one value framework. First, important moments of the value theory from the economic perspective are presented, leading to the marginal revolution of (not only) the Austrian School. Then the theory of value within cultural heritage and environmental economics are explored. Finally, individual approaches are compared and their potential mutual inspiration searched for.
Keywords: Cultural heritage, environmental economics, existence value, value theory.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18935933 Personnel Marketing as Perceived by HR Managers in Czech Republic: Results of a Qualitative Research Study
Authors: Lukáš Mazánek, Zdeňka Konečná
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The article is devoted to the area of personnel marketing. A comprehensive review of scientific literature and articles published predominantly in personnel-oriented journals was carried out, followed by a qualitative exploratory research with the aim to explore and explain the perception of personnel marketing. Due to the lack of research in this field in Czech Republic, we have focused on Czech HR managers, more specifically, on how they understand the tasks of personnel marketing, which tools they use and whether the companies they work for try to be a preferred employer. The answers from our respondents were used to help us determine what is important within this field. All of the respondents strive to be a preferred employer and try to achieve it by using an extensive range of marketing tools. The most frequently used tools are advertising, job fairs presentations, employee care and employer brand promotion.
Keywords: Czech Republic, personnel marketing, preferred employer, qualitative research study.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12225932 Modeling and Simulations of Surface Plasmon Waveguide Structures
Authors: Moussa Hamdan, Abdulati Abdullah
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This paper presents an investigation of the fabrication of the optical devices in terms of their characteristics based on the use of the electromagnetic waves. Planar waveguides are used to examine the field modes (bound modes) and the parameters required for this structure. The modifications are conducted on surface plasmons based waveguides. Simple symmetric dielectric slab structure is used and analyzed in terms of transverse electric mode (TE-Mode) and transverse magnetic mode (TM-Mode. The paper presents mathematical and numerical solutions for solving simple symmetric plasmons and provides simulations of surface plasmons for field confinement. Asymmetric TM-mode calculations for dielectric surface plasmons are also provided.Keywords: Surface plasmons, optical waveguides, semiconductor lasers, refractive index, slab dialectical.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16605931 Shell Closures in Exotic Nuclei
Authors: G. Saxena, D. Singh, M. Kaushik,
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Inspired by the recent experiments [1]-[3] indicating unusual doubly magic nucleus 24O which lies just at the neutron drip-line and encouraged by the success of our relativistic mean-field (RMF) plus state dependent BCS approach for the description of the ground state properties of the drip-line nuclei [23]-[27], we have further employed this approach, across the entire periodic table, to explore the unusual shell closures in exotic nuclei. In our RMF+BCS approach the single particle continuum corresponding to the RMF is replaced by a set of discrete positive energy states for the calculations of pairing energy. Detailed analysis of the single particle spectrum, pairing energies and densities of the nuclei predict the unusual proton shell closures at Z = 6, 14, 16, 34, and unusual neutron shell closures at N = 6, 14, 16, 34, 40, 70, 112.Keywords: Relativistic Mean Field theory, Magic Nucleus, Si isotopes, Shell Closure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15035930 The Effect of Entrepreneurship on Foreign Direct Investment
Authors: Wissam B. Fahed
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Entrepreneurship has become an important and extensively researched concept in business studies. Research on foreign direct investment (FDI) has become widespread due to the growth of FDI and its importance in globalization. Most entrepreneurship studies examined the importance and influence of entrepreneurial orientation in a micro-level context. On the other hand, studies and research concerning FDI used statistical techniques to analyze the effect, determinants, and motives of FDI on a macroeconomic level, ignoring empirical studies on other noneconomic determinants. In order to bridge the gap between the theory and empirical evidence on FDI and the theory and research on entrepreneurship, this study examines the impact of entrepreneurship on inward foreign direct investment. The relationship between entrepreneurship and foreign direct investment is investigated through regression analysis of pooled time-series and cross-sectional data. The results suggest that entrepreneurship has a significant effect on FDI.Keywords: Entrepreneurship, foreign direct investment, globalization, economic freedom.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 38875929 Optimal Distribution of Lift Gas in Gas Lifted Oil Field Using MPC and Unscented Kalman Filter
Authors: Roshan Sharma, Bjørn Glemmestad
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In gas lifted oil fields, the lift gas should be distributed optimally among the wells which share gas from a common source to maximize total oil production. One of the objectives of the paper is to show that a linear MPC consisting of a control objective and an economic objective can be used both as an optimizer and a controller for gas lifted systems. The MPC is based on linearized model of the oil field developed from first principles modeling. Simulation results show that the total oil production is increased by 3.4%. Difficulties in accurately measuring the bottom hole pressure using sensors in harsh operating conditions can be resolved by using an Unscented Kalman Filter (UKF) for estimation. In oil fields where input disturbance (total supply of gas) is not measured, UKF can also be used for disturbance estimation. Increased total oil production due to optimization leads to increased profit.
Keywords: gas lift, MPC, oil production, optimization, Unscented Kalman filter.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26555928 Effect of Drought Stress and Selenium Spraying on Superoxide Dismotase Activity of Winter Rapeseed (Brassica napus L.) Cultivars
Authors: A.R. Pazoki, A. H. Shirani Rad, D. Habibi, F. Paknejad, S. Kobraee, N. Hadayat
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In the other to Study of drought stress and Selenium spraying effect on superoxide dismotase (SOD) activity of rapeseed (Brassica napus L.) cultivars in Shahr-e-Rey region, an experiment carried out in Split factorial design in the basis of randomized complete blocks with 4 replications in 2006. Irrigation in two levels: Normal irrigation and irrigation with drought stress when the soil electrical conductivity reached to 60 as main factor and rapeseed cultivars in 3 levels Zarfam, Okapi, Opera and selenium spraying at the beginning of flowering stage in 3 levels: 0, 16 and 21 g/ha as sub factor. The results showed that the simple and interaction effect of irrigation, selenium and cultivars on SOD activity had significant difference. In this case Zarfam cultivar with 2010 u.mg-1 protein and Opera with 1454 u.mg-1 protein produced maximum and minimum amounts of SOD activitiy. Interaction effect of irrigation and variety showed that, normal irrigation in Opera with 1115 u.mg-1 protein and drought stress in Zarfam with 2784 u.mg-1 protein conducted to and minimum and maximum amounts of SOD activity. Interaction effect of irrigation, cultivar and selenium on SOD indicated that drought stress condition and 21 gr/ha selenium spraying in Zarfam variety with 3146 u.mg-1 protein gained to highest activities of SOD.Keywords: Drought stress, Rapeseed, Selenium, Superoxide dismutase.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19675927 Electromagnetic Imaging of Inhomogeneous Dielectric Cylinders Buried in a Slab Mediumby TE Wave Illumination
Authors: Chung-Hsin Huang, Chien-Ching Chiu, Chun Jen Lin
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The electromagnetic imaging of inhomogeneous dielectric cylinders buried in a slab medium by transverse electric (TE) wave illumination is investigated. Dielectric cylinders of unknown permittivities are buried in second space and scattered a group of unrelated waves incident from first space where the scattered field is recorded. By proper arrangement of the various unrelated incident fields, the difficulties of ill-posedness and nonlinearity are circumvented, and the permittivity distribution can be reconstructed through simple matrix operations. The algorithm is based on the moment method and the unrelated illumination method. Numerical results are given to demonstrate the capability of the inverse algorithm. Good reconstruction is obtained even in the presence of additive Gaussian random noise in measured data. In addition, the effect of noise on the reconstruction result is also investigated.Keywords: Slab Medium, Unrelated Illumination Method, TEWave Illumination, Inhomogeneous Cylinders.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12045926 Free Vibration Analysis of Functionally Graded Pretwisted Plate in Thermal Environment Using Finite Element Method
Authors: S. Parida, S. C. Mohanty
Abstract:
The free vibration behavior of thick pretwisted cantilevered functionally graded material (FGM) plate subjected to the thermal environment is investigated numerically in the present paper. A mathematical model is developed in the framework of higher order shear deformation theory (HOST) with C0 finite element formulation i.e. independent displacement and rotations. The material properties are assumed to be temperature dependent and vary continuously through the thickness based on the volume fraction exponent in simple power rule. The finite element model has been discretized into eight node quadratic serendipity elements with node wise seven degrees of freedom. The effect of plate geometry, temperature field, material composition, and the modal analysis on the vibrational characteristics is examined. Finally, the results are verified by comparing with those available in literature.
Keywords: FGM, pretwisted plate, thermal environment, HOST, simple power law.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7885925 A Lossless Watermarking Based Authentication System For Medical Images
Authors: Samia Boucherkha, Mohamed Benmohamed
Abstract:
In this paper we investigate the watermarking authentication when applied to medical imagery field. We first give an overview of watermarking technology by paying attention to fragile watermarking since it is the usual scheme for authentication.We then analyze the requirements for image authentication and integrity in medical imagery, and we show finally that invertible schemes are the best suited for this particular field. A well known authentication method is studied. This technique is then adapted here for interleaving patient information and message authentication code with medical images in a reversible manner, that is using lossless compression. The resulting scheme enables on a side the exact recovery of the original image that can be unambiguously authenticated, and on the other side, the patient information to be saved or transmitted in a confidential way. To ensure greater security the patient information is encrypted before being embedded into images.Keywords: Medical Imaging, Invertible Watermarking, Authentication, Integrity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2666