Search results for: Range Controllers
1499 Equilibrium Modeling of Carbon Dioxide Adsorption on Zeolites
Authors: Alireza Behvandi, Somayeh Tourani
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High pressure adsorption of carbon dioxide on zeolite 13X was investigated in the pressure range (0 to 4) Mpa and temperatures 298, 308 and 323K. The data fitting is accomplished with the Toth, UNILAN, Dubinin-Astakhov and virial adsorption models which are generally used for micro porous adsorbents such as zeolites. Comparison with experimental data from the literature indicated that the virial model would best determine results. These results may be partly attributed to the flexibility of the virial model which can accommodate as many constants as the data warrants.Keywords: adsorption models, zeolite, carbon dioxide
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28841498 Collaborative Tracking Control of UAV-UGV
Authors: Jae-Young Choi, Sung-Gaun Kim
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This paper suggests a fast and stable Target Tracking system in collaborative control of UAV and UGV. Wi-Fi communication range is limited in collaborative control of UAV and UGV. Thus, to secure a stable communications, UAV and UGV have to be kept within a certain distance from each other. But existing method which uses UAV Vertical Camera to follow the motion of UGV is likely to lose a target with a sudden movement change. Eventually, UGV has disadvantages that it could only move at a low speed and not make any sudden change of direction in order to keep track of the target. Therefore, we suggest utilizing AR Drone UAV front camera to track fast-moving and Omnidirectional Mecanum Wheel UGV.Keywords: Collaborative control, UAV, UGV, Target Tracking.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 29431497 Design Development of Floating Performance Structure for Coastal Areas in the Maltese Islands
Authors: Rebecca E. Dalli Gonzi, Joseph Falzon
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Background: Islands in the Mediterranean region offer opportunities for various industries to take advantage of the facilitation and use of versatile floating structures in coastal areas. In the context of dense land use, marine structures can contribute to ensure both terrestrial and marine resource sustainability. Objective: The aim of this paper is to present and critically discuss an array of issues that characterize the design process of a floating structure for coastal areas and to present the challenges and opportunities of providing such multifunctional and versatile structures around the Maltese coastline. Research Design: A three-tier research design commenced with a systematic literature review. Semi-structured interviews with stakeholders including a naval architect, a marine engineer and civil designers were conducted. A second stage preceded a focus group with stakeholders in design and construction of marine lightweight structures. The three tier research design ensured triangulation of issues. All phases of the study were governed by research ethics. Findings: Findings were grouped into three main themes: excellence, impact and implementation. These included design considerations, applications and potential impacts on local industry. Literature for the design and construction of marine structures in the Maltese Islands presented multiple gaps in the application of marine structures for local industries. Weather conditions, depth of sea bed and wave actions presented limitations on the design capabilities of the structure. Conclusion: Water structures offer great potential and conclusions demonstrate the applicability of such designs for Maltese waters. There is still no such provision within Maltese coastal areas for multi-purpose use. The introduction of such facilities presents a range of benefits for visiting tourists and locals thereby offering wide range of services to tourism and marine industry. Costs for construction and adverse weather conditions were amongst the main limitations that shaped design capacities of the water structures.Keywords: Coastal areas, lightweight, marine structure, multipurpose, versatile, floating device.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 9411496 Flow and Heat Transfer over a Shrinking Sheet: A Stability Analysis
Authors: Anuar Ishak
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The characteristics of fluid flow and heat transfer over a permeable shrinking sheet is studied. The governing partial differential equations are transformed into a set of ordinary differential equations, which are then solved numerically using MATLAB routine boundary value problem solver bvp4c. Numerical results show that dual solutions are possible for a certain range of the suction parameter. A stability analysis is performed to determine which solution is linearly stable and physically realizable.
Keywords: Dual solutions, heat transfer, shrinking sheet, stability analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 20171495 The Semantic Web: a New Approach for Future World Wide Web
Authors: Sahar Nasrolahi, Mahdi Nikdast, Mehrdad Mahdavi Boroujerdi
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The purpose of semantic web research is to transform the Web from a linked document repository into a distributed knowledge base and application platform, thus allowing the vast range of available information and services to be more efficiently exploited. As a first step in this transformation, languages such as OWL have been developed. Although fully realizing the Semantic Web still seems some way off, OWL has already been very successful and has rapidly become a defacto standard for ontology development in fields as diverse as geography, geology, astronomy, agriculture, defence and the life sciences. The aim of this paper is to classify key concepts of Semantic Web as well as introducing a new practical approach which uses these concepts to outperform Word Wide Web.Keywords: Semantic Web, Ontology, OWL, Microformat, Word Wide Web.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16001494 Design of Digital Differentiator to Optimize Relative Error
Authors: Vinita V. Sondur, Vilas B. Sondur, Narasimha H. Ayachit
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It is observed that the Weighted least-square (WLS) technique, including the modifications, results in equiripple error curve. The resultant error as a percent of the ideal value is highly non-uniformly distributed over the range of frequencies for which the differentiator is designed. The present paper proposes a modification to the technique so that the optimization procedure results in lower maximum relative error compared to the ideal values. Simulation results for first order as well as higher order differentiators are given to illustrate the excellent performance of the proposed method.Keywords: Differentiator, equiripple, error distribution, relative error.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12271493 Response Spectrum Transformation for Seismic Qualification Testing
Authors: Nouredine Bourahla, Farid Bouriche, Yacine Benghalia
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Seismic qualification testing for equipments to be mounted on upper storeys of buildings is very demanding in terms of floor spectra. The latter is characterized by high accelerations amplitudes within a narrow frequency band. This article presents a method which permits to cover specified required response spectra beyond the shaking table capability by amplifying the acceleration amplitudes at an appropriate frequency range using a physical intermediate mounted on the platform of the shaker.Keywords: floor spectra, response spectrum, seismicqualification testing, shaking table
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18391492 Smart Security Concept in the East Mediterranean: Anti-Asymmetrical Area Denial (A3D)
Authors: Serkan Tezgel, Osman Gül, İskender Cahit Şafak
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This paper proposes the application of the Smart Security Concept in the East Mediterranean. Smart Security aims to secure critical infrastructure, such as hydrocarbon platforms, against asymmetrical threats. The concept is based on Anti Asymmetrical Area Denial (A3D) which necessitates limiting freedom of action of maritime terrorists and piracy by founding safe and secure maritime areas through sea lines of communication using short range capabilities.Keywords: Partnership, A3D, Maritime Security, Centers.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 18771491 Study of Water on the Surface of Nano-Silica Material: An NMR Study
Authors: J. Hassan
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Water 2H NMR signal on the surface of nano-silica material, MCM-41, consists of two overlapping resonances. The 2H water spectrum shows a superposition of a Lorentzian line shape and the familiar NMR powder pattern line shape, indicating the existence of two spin components. Chemical exchange occurs between these two groups. Decomposition of the two signals is a crucial starting point for study the exchange process. In this article we have determined these spin component populations along with other important parameters for the 2H water NMR signal over a temperature range between 223 K and 343 K.
Keywords: Nano-Silica, surface water, NMR
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15211490 Analysis of Bit Error Rate Improvement in MFSK Communication Link
Authors: O. P. Sharma, V. Janyani, S. Sancheti
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Data rate, tolerable bit error rate or frame error rate and range & coverage are the key performance requirement of a communication link. In this paper performance of MFSK link is analyzed in terms of bit error rate, number of errors and total number of data processed. In the communication link model proposed, which is implemented using MATLAB block set, an improvement in BER is observed. Different parameters which effects and enables to keep BER low in M-ary communication system are also identified.Keywords: Additive White Gaussian Noise (AWGN), Bit Error Rate (BER), Frequency Shift Keying (FSK), Orthogonal Signaling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28891489 Toxicity of Copper and Cadmium to Freshwater Fishes
Authors: M. Shuhaimi-Othman, Y. Nadzifah, A.K. Ahmad
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Two freshwater fishes, Rasbora sumatrana (Cyprinidae) and Poecilia reticulata (guppy) (Poeciliidae) were exposed for a four-day period in the laboratory condition to a range of copper (Cu) and cadmium (Cd) concentrations. Mortality was assessed and median lethal concentrations (LC50) were calculated. LC50 increased with decrease in mean exposure times for both metals. For R. sumatrana, LC50s for 24, 48, 72 and 96 hours for Cu were 54.2, 30.3, 18.9 and 5.6 μg/L and for Cd 1440.2, 459.3, 392.3 and 101.6 μg/L respectively. For P. reticulata, LC50s for 24, 48, 72 and 96 hours for Cu were 348.9, 145.4, 61.3 and 37.9 μg/L and for Cd 8205.6, 2827.1, 405.8 and 168.1 μg/L, respectively. Results indicated that the Cu was more toxic than Cd to both fishes (Cu>Cd) and R. sumatrana was more sensitive than P. reticulata to the metals.Keywords: Acute, heavy metals, LT50, toxicity
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 37311488 Evaluation of Hydrocarbons in Tissues of Bivalve Mollusks from the Red Sea Coast
Authors: A. Aljohani, M. Orif
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The concentration of polycyclic aromatic hydrocarbons (PAH) in clams (A. glabrata) was examined in samples collected from Alseef Beach, 30 km south of Jeddah city. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the 14 PAHs. The concentration of total PAHs was found to range from 11.521 to 40.149 ng/gdw with a mean concentration of 21.857 ng/gdw, which is lower compared to similar studies. The lower molecular weight PAHs with three rings comprised 18.14% of the total PAH concentrations in the clams, while the high molecular weight PAHs with four rings, five rings, and six rings account for 81.86%. Diagnostic ratios for PAH source distinction suggested pyrogenic or anthropogenic sources.
Keywords: Bivalves, biomonitoring, hydrocarbons, PAHs.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1741487 Coexistence of Two Different Types of Intermittency near the Boundary of Phase Synchronization in the Presence of Noise
Authors: Olga I. Moskalenko, Maksim O. Zhuravlev, Alexey A. Koronovskii, Alexander E. Hramov
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Intermittent behavior near the boundary of phase synchronization in the presence of noise is studied. In certain range of the coupling parameter and noise intensity the intermittency of eyelet and ring intermittencies is shown to take place. Main results are illustrated using the example of two unidirectional coupled Rössler systems. Similar behavior is shown to take place in two hydrodynamical models of Pierce diode coupled unidirectional.Keywords: Chaotic oscillators, phase synchronization, noise, intermittency of intermittencies, control.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19521486 0.13-µm Complementary Metal-Oxide Semiconductor Vector Modulator for Beamforming System
Authors: J. S. Kim
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This paper presents a 0.13-µm Complementary Metal-Oxide Semiconductor (CMOS) vector modulator for beamforming system. The vector modulator features a 360° phase and gain range of -10 dB to 10 dB with a root mean square phase and amplitude error of only 2.2° and 0.45 dB, respectively. These features make it a suitable for wireless backhaul system in the 5 GHz industrial, scientific, and medical (ISM) bands. It draws a current of 20.4 mA from a 1.2 V supply. The total chip size is 1.87x1.34 mm².
Keywords: CMOS, vector modulator, beamforming, wireless backhaul, ISM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10561485 Study of Proton-9,11Li Elastic Scattering at 60~75 MeV/Nucleon
Authors: Arafa A. Alholaisi, Jamal H. Madani, M. A. Alvi
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The radial form of nuclear matter distribution, charge and the shape of nuclei are essential properties of nuclei, and hence, are of great attention for several areas of research in nuclear physics. More than last three decades have witnessed a range of experimental means employing leptonic probes (such as muons, electrons etc.) for exploring nuclear charge distributions, whereas the hadronic probes (for example alpha particles, protons, etc.) have been used to investigate the nuclear matter distributions. In this paper, p-9,11Li elastic scattering differential cross sections in the energy range to MeV have been studied by means of Coulomb modified Glauber scattering formalism. By applying the semi-phenomenological Bhagwat-Gambhir-Patil [BGP] nuclear density for loosely bound neutron rich 11Li nucleus, the estimated matter radius is found to be 3.446 fm which is quite large as compared to so known experimental value 3.12 fm. The results of microscopic optical model based calculation by applying Bethe-Brueckner–Hartree–Fock formalism (BHF) have also been compared. It should be noted that in most of phenomenological density model used to reproduce the p-11Li differential elastic scattering cross sections data, the calculated matter radius lies between 2.964 and 3.55 fm. The calculated results with phenomenological BGP model density and with nucleon density calculated in the relativistic mean-field (RMF) reproduces p-9Li and p-11Li experimental data quite nicely as compared to Gaussian- Gaussian or Gaussian-Oscillator densities at all energies under consideration. In the approach described here, no free/adjustable parameter has been employed to reproduce the elastic scattering data as against the well-known optical model based studies that involve at least four to six adjustable parameters to match the experimental data. Calculated reaction cross sections σR for p-11Li at these energies are quite large as compared to estimated values reported by earlier works though so far no experimental studies have been performed to measure it.
Keywords: Bhagwat-Gambhir-Patil density, coulomb modified Glauber model, halo nucleus, optical limit approximation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7251484 Phase Diagram Including a Negative Pressure Region for a Thermotropic Liquid Crystal in a Metal Berthelot Tube
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Thermodynamic properties of liquids under negative pressures are interesting and important in fields of scienceand technology. Here, phase transitions of a thermotropic liquid crystal are investigatedin a range from positive to negative pressures with a metal Berthelot tube using a commercial pressure transducer.Two co-existinglines, namely crystal (Kr) –nematic (N), and isotropic liquid (I) - nematic (N) lines, weredrawn in a pressure - temperature plane. The I-N line was drawn to ca. -5 (MPa).
Keywords: Berthelot method, liquid crystal, negative pressure.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16971483 Non-Isolated Direct AC-DC Converter Design with BCM-PFC Circuit
Authors: Y. Kobori, L. Xing, H. Gao, N.Onozawa, S. Wu, S. N. Mohyar, Z. Nosker, H. Kobayashi, N. Takai, K. Niitsu
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This paper proposes two types of non-isolated direct AC-DC converters. First, it shows a buck-boost converter with an H-bridge, which requires few components (three switches, two diodes, one inductor and one capacitor) to convert AC input to DC output directly. This circuit can handle a wide range of output voltage. Second, a direct AC-DC buck converter is proposed for lower output voltage applications. This circuit is analyzed with output voltage of 12V. We describe circuit topologies, operation principles and simulation results for both circuits.Keywords: AC-DC converter, Buck-boost converter, Buck converter, PFC, BCM PFC circuit.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 47911482 Mobility Management Enhancement for Transferring AAA Context in Mobile Grid
Authors: Hee Suk Seo, Tae Kyung Kim
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Adapting wireless devices to communicate within grid networks empowers us by providing range of possibilities.. These devices create a mechanism for consumers and publishers to create modern networks with or without peer device utilization. Emerging mobile networks creates new challenges in the areas of reliability, security, and adaptability. In this paper, we propose a system encompassing mobility management using AAA context transfer for mobile grid networks. This system ultimately results in seamless task processing and reduced packet loss, communication delays, bandwidth, and errors.Keywords: Mobile Grid, AAA, Mobility Management.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15671481 Genetic Mining: Using Genetic Algorithm for Topic based on Concept Distribution
Authors: S. M. Khalessizadeh, R. Zaefarian, S.H. Nasseri, E. Ardil
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Today, Genetic Algorithm has been used to solve wide range of optimization problems. Some researches conduct on applying Genetic Algorithm to text classification, summarization and information retrieval system in text mining process. This researches show a better performance due to the nature of Genetic Algorithm. In this paper a new algorithm for using Genetic Algorithm in concept weighting and topic identification, based on concept standard deviation will be explored.Keywords: Genetic Algorithm, Text Mining, Term Weighting, Concept Extraction, Concept Distribution.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 37141480 Inhibition Kinetic Determination of Trace Amounts of Ruthenium(III) by the Spectrophotometric method with Rhodamine B in Micellar Medium
Authors: Mohsen Keyvanfard
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A new, simple and highly sensitive kinetic spectrophotometric method was developed for the determination of trace amounts of Ru(III) in the range of 0.06-20 ng/ml .The method is based on the inhibitory effect of ruthenium(III) on the oxidation of Rhodamine B by bromate in acidic and micellar medium. The reaction was monitored spectrophotometrically by measuring the decreasing in absorbance of Rhodamine B at 554 nm with a fixedtime method..The limit of detection is 0.04 ng/ml Ru(III).The relative standard deviation of 5 and 10 ng/ml Ru(III) was 2.3 and 2.7 %, respectively. The method was applied to the determination of ruthenium in real water samplesKeywords: Ruthenium ;Inhibitory; Rhodamine B; bromate
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17071479 The Link between Financial and Overall Corporate Strategies
Authors: Jaroslav Pavlíček
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Company strategy expresses a basic idea of how to reach company objectives. A whole range of models of strategic management are used in practice. The concept of strategic management should fulfill some basic requirements to make it applicable for both the typical, but also more specific company environment. The financial strategy plays an important role in corporate strategy. The paper develops a methodology of strategic model implementing into the category of micro, small and medium-sized enterprises (SMEs). Furthermore, the methodology recommends procedures while solving an up-to-date worldwide task of the definition of the company strategy and its financial strategy.
Keywords: corporate strategy, financial strategy, corporate planning
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19511478 Design of a Novel CPW Fed Fractal Antenna for UWB
Authors: A. El Hamdouni, J. Zbitou, A. Tajmouati, L. El Abdellaoui, A. Errkik, A. Tribak, M. Latrach
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This paper presents a novel fractal antenna structure proposed for UWB (Ultra – Wideband) applications. The frequency band 3.1-10.6GHz released by FCC (Federal Communication Commission) as the commercial operation of UWB has been chosen as frequency range for this antenna based on coplanar waveguide (CPW) feed and circular shapes fulfilled according to fractal geometry. The proposed antenna is validated and designed by using an FR4 substrate with overall area of 34x43 mm2. The simulated results performed by CST-Microwave Studio and compared by ADS (Advanced Design System) show good matching input impedance with return loss less than -10dB between 2.9 GHz and 11 GHz.
Keywords: Fractal antenna, Fractal Geometry, CPW Feed, UWB, FCC.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22421477 Heat Transfer from Two Cam Shaped Cylinders in Side-by-Side Arrangement
Authors: Arash Mir Abdolah Lavasani, Hamidreza Bayat
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Heat transfer from two cam shape cylinder in side-byside arrangement had been studied numerically. The transverse gap between the centers of cylinders (T) is allowed to vary to change the pitch ratio (T/Deq). The equivalent diameter of the cylinder (Deq) is 27.6 mm and pitch ratio varies in range of 1≤T/Deq≤3. The Reynolds numbers based on equivalent circular cylinder are within 50≤ Reeq≤150. Results show that Nusselt number of cylinders increases about 1 to 36 percent when pitch ratio increases from 1 to 3.Keywords: Cam shaped, side-by-side cylinders, numerical, heat Transfer.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15071476 A TISM Model for Structuring the Productivity Elements of Flexible Manufacturing System
Authors: Sandhya Dixit, Tilak Raj
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Flexible Manufacturing System (FMS) is seen as an option for industries which want to boost productivity as well as respond quickly to an increasingly changing marketplace. FMS produces in mid variety, mid volume range and can meet the changing market demands very quickly. But still the impact of adoption of FMS on the productivity of any industry is not very clear. In this paper an attempt has been made to model the various factors affecting the productivity of FMS installation using Total Interpretive Structural Modelling (TISM) Technique.Keywords: Flexible manufacturing system, productivity, total interpretive structural modelling.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11441475 Coherent and Incoherent Scattering Cross Sections for Elements with 13
Authors: Panakkada Latha, K. K. Abdullah, M. P. Unnikrishnan, K. M. Varier, B. R. S. Babu
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Coherent and incoherent scattering cross section measurements have been carried out using a HPGe detector on elements in the range of Z = 13 - 50 using 241Am gamma rays. The cross sections have been derived by comparing the net count rate obtained from the Compton peak of aluminium with the corresponding peak of the target. The measured cross sections for the coherent and incoherent processes are compared with theoretical values and earlier reported values. Our results are in agreement with the theoretical values.
Keywords: Cross section, coherent scattering, incoherent scattering, 241Am.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23851474 Optically Active Material Based on Bi2O3@Yb3+, Nd3+ with High Intensity of Upconversion Luminescence in the Red and Green Region
Authors: D. Artamonov, A. Tsibulnikova, I. Samusev, V. Bryukhanov, A. Kozhevnikov
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The synthesis and luminescent properties of Yb2O3,Nd2O3@Bi2O3 complex with upconversion generation are discussed in this work. The obtained samples were measured in the visible region of the spectrum under excitation with a wavelength of 980 nm. The studies showed that the obtained complexes have a high degree of stability and intense luminescence in the wavelength range of 400-750 nm. Consideration of the time dependence of the intensity of the upconversion luminescence allowed us to conclude that the enhancement of the intensity occurs in the time interval from 5 to 30 min, followed by the appearance of a stationary mode.
Keywords: Lasers, luminescence, upconversion photonics, rare earth metals.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1731473 Steady State Thermal Analysis and Design of a Cooling System in an AFPM Motor
Authors: K. Sarrafan, A. Darabi
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In this paper, the steady-state temperature of a sample 500 KW two rotor one stator Non-slotted axial flux permanent magnet motor is calculated using the finite element simulator software package. Due to the high temperature in various parts of the machine, especially at stator winding, a cooling system is designed for the motor and the temperature is recalculated. The results show that the temperature obtained for the parts is within the permissible range.Keywords: Axial Flux, Cooling System, Permanent Magnet, Thermal Analysis.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 27371472 Effect of L/D Ratio on the Performance of a Four-Lobe Pressure Dam Bearing
Authors: G. Bhushan, S. S. Rattan, N. P. Mehta
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A four-lobe pressure dam bearing which is produced by cutting two pressure dams on the upper two lobes and two relief-tracks on the lower two lobes of an ordinary four-lobe bearing is found to be more stable than a conventional four-lobe bearing. In this paper a four-lobe pressure dam bearing supporting rigid and flexible rotors is analytically investigated to determine its performance when L/D ratio is varied in the range 0.75 to 1.5. The static and dynamic characteristics are studied at various L/D ratios. The results show that the stability of a four-lobe pressure dam bearing increases with decrease in L/D ratios both for rigid as well as flexible rotors.Keywords: Four-lobe pressure dam bearing, finite-elementmethod, L/D ratio.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 26421471 Foil Bearing Stiffness Estimation with Pseudospectral Scheme
Authors: Balaji Sankar, Sadanand Kulkarni
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Compliant foil gas lubricated bearings are used for the support of light loads in the order of few kilograms at high speeds, in the order of 50,000 RPM. The stiffness of the foil bearings depends both on the stiffness of the compliant foil and on the lubricating gas film. The stiffness of the bearings plays a crucial role in the stable operation of the supported rotor over a range of speeds. This paper describes a numerical approach to estimate the stiffness of the bearings using pseudo spectral scheme. Methodology to obtain the stiffness of the foil bearing as a function of weight of the shaft is given and the results are presented.Keywords: Foil bearing, simulation, numerical, stiffness estimation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12421470 Modeling of CO2 Removal from Gas Mixtureby 2-amino-2-methyl-1-propanol (AMP) Using the Modified Kent Eisenberg Model
Authors: H. Pahlavanzadeh, A.R.Jahangiri, I. Noshadi
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In this paper, the solubility of CO2 in AMP solution have been measured at temperature range of ( 293, 303 ,313,323) K.The amine concentration ranges studied are (2.0, 2.8, and 3.4) M. A solubility apparatus was used to measure the solubility of CO2 in AMP solution on samples of flue gases from Thermal and Central Power Plants of Esfahan Steel Company. The modified Kent Eisenberg model was used to correlate and predict the vapor-liquid equilibria of the (CO2 + AMP + H2O) system. The model predicted results are in good agreement with the experimental vapor-liquid equilibrium measurements.Keywords: AMP, Carbon dioxide; loading, Flue gases, Modified Kent Eisenberg model
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2479