Search results for: compact polarimetry

Authors: Naser Ojaroudi Parchin, Atta Ullah, Haleh Jahanbakhsh Basherlou, Raed A. Abd-Alhameed, Peter S. Excell

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A design of beam-steerable antenna array for the future cellular communication (5G) is presented. The proposed design contains eight elements of compact end-fire antennas arranged on the top edge of smartphone printed circuit board (PCB). Configuration of the antenna element consists of the conductive patterns on the top and bottom copper foil layers and a substrate layer with a via-hole. The simulated results including input-impedance and also fundamental radiation properties have been presented and discussed. The impedance bandwidth (S₁₁ ≤ -10 dB) of the antenna spans from 17.5 to 21 GHz (more than 3 GHz bandwidth) with a resonance at 19 GHz. The antenna exhibits end-fire (directional) radiation beams with wide-angle scanning property and could be used for the future 5G beam-forming. Furthermore, the characteristics of the array design in the vicinity of user-hand are studied.

Keywords: beam-steering, end-fire radiation mode, mobile-phone antenna, phased array

Procedia PDF Downloads 122

Authors: Onkar Nath Verma, Nitish Kumar Singh, Raghvendra, Pravin Kumar, Prabhakar Singh

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The perovskite type electrolyte material LaAlO3 was prepared by solution based auto-combustion method using Al (NO3)3.6H2O, La2O3 with dilute nitrate acid (HNO3) as precursors and citric acid (C6H8O7.H2O) as a fuel. The synthesis protocol gave an easy processing of the LaAlO3 nano-particles. The XRD measurement revealed that the material has single phase with space group R-3c (rhombohedral). Thermal behavior was measured by simultaneous differential thermal analysis and thermo gravimetric analysis (DTA-TGA). The compact pellet density was determined. Also, the surface morphology was studied using scanning electron microscopy (SEM). The conductivity of LaAlO3 was measured employing LCR meter and found to increase with increasing temperature. This increase in conductivity may be attributed to increased mobility of oxide ion.

Keywords: perovskite, LaAlO3, XRD, SEM, DTA-TGA, SOFC

Procedia PDF Downloads 475

Authors: Rajaramamohanarao Chennu, S. Sudhakara Reddy, Gurudev T, Maroti

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With the invent of recent available technology and cost optimization, the switchgear assemblies are becoming more compact and designed to operate at critical levels of thermal and dielectric stress. At the same time, the switchgear assemblies shall be designed for protection of persons, met in the event of internal arc for specified installation conditions, according to the latest available national/international standards. These standards are revising regularly for better product design and personal safety. The switchgear assemblies design shall be modified in accordance with the change in requirements in the latest edition of the standards. This paper presents the signifying changes brought in the latest edition of 62271-200:2021 and effect of these changes and the necessitated design improvements for meeting internal arc test requirements is presented by carrying out the internal arc testing experiments on the switchgear assemblies at High Power Laboratory, Central Power Research Institute, Bangalore, India.

Keywords: internal arc, switchgear assembly, high speed videography, IEC 62271-200

Procedia PDF Downloads 161

Authors: Inderpreet Kaur, Sukhjit Kaur, Balwinder Singh Sohi

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The design proposed in this paper mainly focuses on implementation of a single feed compact rectangular microstrip patch antenna (MSA) for single band application. The antenna presented here also works in dual band but its best performance has been obtained when optimised to work in single band mode. In this paper, a new feeding structure is applied in the patch antenna design to overcome undesirable features of the earlier multilayer feeding structures while maintaining their interesting features.To make the proposed antenna more efficient the optimization of the antenna design parameters have been done using HFSS’s optometric. For the proposed antenna one resonant frequency has been obtained at 6.03GHz, with Bandwidth of 167MHz and return loss of -33.82db. The characteristics of the designed structure are investigated by using FEM based electromagnetic solver.

Keywords: bandwidth, retun loss, parasitic lines, microstrip antenna

Procedia PDF Downloads 437

Authors: Sadeep Sasidharan, T. B. Isha

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Modern day electric vehicles require compact high torque/power density motors for electric propulsion. This necessitates proper thermal management of the electric motors. The main focus of this paper is to compare the steady state thermal analysis of a conventional 20 kW 8/6 Switched Reluctance Motor (SRM) with that of an Induction Motor and Inset Permanent Magnet (IPM) motor of the same rating. The goal is to develop a proper thermal model of the three types of models for Finite Element Thermal Analysis. JMAG software is used for the development and simulation of the thermal models. The results show that the induction motor is subjected to more heating when used for electric vehicle application constantly, compared to the SRM and IPM.

Keywords: electric vehicles, induction motor, inset permanent magnet motor, loss models, switched reluctance motor, thermal analysis

Procedia PDF Downloads 192

Authors: Aziza Ben Halima, Julien Bert, Dimitris Visvikis

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In this paper, we propose designing and evaluating a parallel co-manipulated robot dedicated to low-dose-rate prostate brachytherapy. We developed 6 degrees of freedom compact and lightweight robot easy to install in the operating room thanks to its parallel design. This robotic system provides a co-manipulation allowing the surgeon to keep control of the needle’s insertion and consequently to improve the acceptability of the plan for the clinic. The best dimension’s configuration was solved by calculating the geometric model and using an optimization approach. The aim was to ensure the whole coverage of the prostate volume and consider the allowed free space around the patient that includes the ultrasound probe. The final robot dimensions fit in a cube of 300 300 300 mm³. A prototype was 3D printed, and the robot workspace was measured experimentally. The results show that the proposed robotic system satisfies the medical application requirements and permits the needle to reach any point within the prostate.

Keywords: medical robotics, co-manipulation, prostate brachytherapy, optimization

Procedia PDF Downloads 175

Authors: N. Aliyu, G. Atkinson, N. Stannard

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Compacted insulated iron powder is a key material in high volume electric motors manufacturing. It offers high production rates, dimensionally stable components, and low scrap volumes. It is the aim of this paper to develop a three-phase compact single sided concentrated winding axial flux PM motor with soft magnetic composite (SMC) core for reducing core losses and cost. To succeed the motor would need to be designed in such a way as to exploit the isotropic magnetic properties of the material and open slot constructions with surface mounted PM for higher speed up to 6000 rpm, without excessive rotor losses. Higher fill factor up to 70% was achieved by compacting the coils, which offered a significant improvement in performance. A finite-element analysis was performed for accurate parameters calculation and the simulation results are thoroughly presented and agree with the theoretical calculations very well.

Keywords: SMC core, axial gap motor, high efficiency, torque

Procedia PDF Downloads 307

Authors: Bairam Khan, Premlata Vaishnava

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The ability to conceptualize one entity in terms of another allows us to communicate through metaphors. This central feature of human cognition has evolved with the development of language, and the processing of metaphors is without any conscious appraisal and is quite effortless. South Asians, like other speech communities, have been using the kitchenary [culinary] metaphor in a very simple yet interesting way and are known for bringing into new and unique constellations wherever they are. This composite feature of our language is used to communicate in a precise and compact manner and maneuvers the expression. The present study explores the role of kitchenary metaphors in the making and shaping of idioms by applying Cognitive Metaphor Theories. Drawing on examples from a corpus of adverts, print, and electronic media, the study looks at the metaphorical language used by real people in real situations. The overarching theme throughout the course is that kitchenary metaphors are powerful tools of expression in Hindi-Urdu.

Keywords: cognitive metaphor theories, kitchenary metaphors, hindi-urdu print, and electronic media, grammatical structure of kitchenary metaphors of hindi-urdu

Procedia PDF Downloads 74

Authors: Richard Mitchell, Robert Mitchell, Thai Duong, Kyungbin Bae, Daegon Kim, Youngsub Lee, Inho Kim, Inho Park, Hyungseok Lee

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Although X-band radar is commonly used to measure the properties of ocean waves, the use of a higher frequency has several advantages, such as increased backscatter coefficient, better Doppler sensitivity, lower power, and a smaller package. A low-power Ku-band radar system was developed to demonstrate these advantages. It is fully coherent, and it interleaves short and long pulses to achieve a transmit duty ratio of 25%, which makes the best use of solid-state amplifiers. The range scales are 2 km, 4 km, and 8 km. The minimum range is 100 m, 200 m, and 400 m for the three range scales, and the range resolution is 4 m, 8 m, and 16 m for the three range scales. Measurements of the significant wave height, wavelength, wave period, and wave direction have been made using traditional 3D-FFT methods. Radar and ultrasonic sensor results collected over an extended period of time at a coastal site in South Korea are presented.

Keywords: measurement of ocean wave parameters, Ku-band radar, coherent radar, compact radar

Procedia PDF Downloads 140

Authors: Sultan Noman Qasem

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This paper presents an evolutionary algorithm for solving multi-objective optimization problems-based artificial neural network (ANN). The multi-objective evolutionary algorithm used in this study is genetic algorithm while ANN used is radial basis function network (RBFN). The proposed algorithm named memetic elitist Pareto non-dominated sorting genetic algorithm-based RBFNN (MEPGAN). The proposed algorithm is implemented on medical diseases problems. The experimental results indicate that the proposed algorithm is viable, and provides an effective means to design multi-objective RBFNs with good generalization capability and compact network structure. This study shows that MEPGAN generates RBFNs coming with an appropriate balance between accuracy and simplicity, comparing to the other algorithms found in literature.

Keywords: radial basis function network, hybrid learning, multi-objective optimization, genetic algorithm

Procedia PDF Downloads 533

Authors: Bairam Khan, Premlata Vaishnava

Abstract:

The ability to conceptualize one entity in terms of another allows us to communicate through metaphors. This central feature of human cognition has evolved with the development of language, and the processing of metaphors is without any conscious appraisal and is quite effortless. South Asians, like other speech communities, have been using the kitchenary [culinary] metaphor in a very simple yet interesting way and are known for bringing into new and unique constellations wherever they are. This composite feature of our language is used to communicate in a precise and compact manner and maneuvers the expression. The present study explores the role of kitchenary metaphors in the making and shaping of idioms by applying Cognitive Metaphor Theories. Drawing on examples from a corpus of adverts, print, and electronic media, the study looks at the metaphorical language used by real people in real situations. The overarching theme throughout the course is that kitchenary metaphors are powerful tools of expression in Hindi-Urdu.

Keywords: cognitive metaphor theory, source domain, target domain, signifier- signified, kitchenary, ethnocultural elements of south asia and hindi- urdu language

Procedia PDF Downloads 50

Authors: Veronika Přivřelová

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Well-designed composite steel and concrete structures highlight the good material properties and lower the deficiencies of steel and concrete, in particular they make use of high tensile strength of steel and high stiffness of concrete. The most common composite steel and concrete structure is a simply supported beam, which concrete slab transferring the slab load to a beam is connected to the steel cross-section. The aim of this paper is to find the most adequate numerical model of a simply supported composite beam with the cross-sectional and material parameters based on the results of a processed parametric study and numerical analysis. The paper also evaluates the suitability of using compact concrete with the lightweight aggregates for composite steel and concrete beams. The most adequate numerical model will be used in the resent future to compare the results of laboratory tests.

Keywords: composite beams, high-performance concrete, high-strength steel, lightweight concrete slab, modeling

Procedia PDF Downloads 372

Authors: Maryam Kiani

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The aim of this study was to investigate the influence of nanoparticles additive on the properties of fly ash-based geopolymer. The geopolymer samples were prepared using fly ash as the primary source material, along with an alkali activator solution and different concentrations of carbon black additive. The effects of nanoparticles flexural strength, water absorption, and micro-structural properties of the cured samples. The results revealed that the inclusion of nanoparticles additive significantly enhanced the mechanical and electrical properties of the geopolymer binder. Micro-structural analysis using scanning electron microscopy (SEM) revealed a more compact and homogeneous structure in the geopolymer samples with nanoparticles. The dispersion of nanoparticles particles within the geopolymer matrix was observed, suggesting improved inter-particle bonding and increased density. Overall, this study demonstrates the positive impact of nanoparticles additive on the qualities of fly ash-based geopolymer, emphasizing its potential as an effective enhancer for geopolymer binder applications for the development of construction and infrastructure for energy buildings.

Keywords: fly-ash, geopolymer, energy buildings, nanotechnology

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Authors: Ruitao Li, Zhili Dong, Nay Win Khun, Khiam Aik Khor

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In this study, microstructure and sintering mechanism as well as wear resistance properties of Ti/Al-Cr-Fe metal matrix composites (MMCs) fabricated by spark plasma sintering (SPS) with Ti as matrix and Al-Cr-Fe as reinforcement were investigated. Phases and microstructure of the sintered samples were analyzed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). Wear resistance properties were tested by ball-on-disk method. An Al3Ti ring forms around each Al-Cr-Fe particle as the bonding layer between Ti and Al-Cr-Fe particles. The Al content in Al-Cr-Fe particles experiences a decrease from 70 at.% to 60 at.% in the sintering process. And these particles consist of quasicrystalline icosahedral AlCrFe and quasicrystal approximants γ-brass Al8(Cr,Fe)5 and Al9(Cr,Fe)4 in the sintered compact. The addition of Al-Cr-Fe particles into the Ti matrix can improve the microhardness by about 40% and the wear resistance is improved by more than 50% due to the increase in the microhardness and the change of wear mechanism.

Keywords: metal matrix composites, spark plasma sintering, phase transformation, wear

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Authors: S. S. Chong, A. R. Abdul Aziz, S. W. Harun, H. Arof

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A miniaturized non-adiabatic silica microfiber is proposed for biological oxygen demand (BOD) ratio chemical oxygen demand (COD) sensing for the first time. BOD and COD are two main parameters to justify quality of wastewater. A ratio, BOD:COD can usually be established between the two analytical methods once COD and BOD value has been gathered. This ratio plays a vital role to determine appropriate strategy in wastewater treatment. A non-adiabatic microfiber sensor was formed by tapering the SMF to generate evanescent field where sensitive to perturbation of sensing medium. Because difference ratio BOD and COD contain in solution, this may induced changes of effective refractive index between microfiber and sensing medium. Attenuation wavelength shift to right with 0.5 nm and 3.5 nm while BOD:COD equal to 0.09 and 0.18 respectively. Significance difference wavelength shift may relate with the biodegradability of analyte. This proposed sensor is compact, reliable and feasible to determine the BOD:COD. Further research and investigation should be proceeded to enhance sensitivity and precision of the sensor for several of wastewater online monitoring.

Keywords: non-adiabatic fiber sensor, environmental sensing, biodegradability, evanescent field

Procedia PDF Downloads 631

Authors: Shaukat Ali, Kanber Sedef, Mustafa Yilmaz

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This work analyzes a finger mechanism for a prosthetic hand that will help in improving the living standards of people who have lost their hands for a variety of reasons. The finger mechanism is single degree of freedom and hence has advantages such as compact size, reduced mass and less energy consumption. The proposed finger mechanism is a six bar linkage actuated by a single motor. The kinematic, static and dynamic analyses have been done by using the conventional methods of mechanism analysis. The kinematic results present the motion of the proposed finger mechanism and location of the fingertip. The static and dynamic analyses provide the useful information about the gripping force at the fingertip for various configurations and the selection of motor that will move the finger over its range of configuration. This single motor finger mechanism is simple and resembles the human finger’s motion suitable for grasping operation. This study can be used in the optimization of geometrical parameters of the proposed mechanism to obtain the desired configurations with minimum torque and enhanced griping.

Keywords: dynamics, finger mechanism, grasping, kinematics

Procedia PDF Downloads 325

Authors: M. Brahim, I. Bahri, Y. Bernard

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Traveling Wave Ultrasonic Motor (TWUM) is a compact, precise, and silent actuator generating high torque at low speed without gears. Moreover, the TWUM has a high holding torque without supply, which makes this motor as an attractive solution for holding position of robotic arms. However, their nonlinear dynamics, and the presence of load-dependent dead zones often limit their use. Those issues can be overcome in closed loop with effective and precise controllers. In this paper, robust H-infinity (H∞) and discrete time RST position controllers are presented. The H∞ controller is designed in continuous time with additional weighting filters to ensure the robustness in the case of uncertain motor model and external disturbances. Robust RST controller based on the pole placement method is also designed and compared to the H∞. Simulink model of TWUM is used to validate the stability and the robustness of the two proposed controllers.

Keywords: piezoelectric motors, position control, H∞, RST, stability criteria, robustness

Procedia PDF Downloads 221

Authors: Mohammad Kousara, Françoise Dumas, Rama Ibrahim, Joëlle Dubois, Joël Raingeaud

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Suberosanes are a small group of marine natural sesquiterpenes discovered since 1996 by Boyd, Sheu and Qi from three gorgonians. Their skeleton was previously found in quadranes produced by the terrestrial fungus Aspergillus terreus. Up to date, eleven suberosanes are described from which (-)-suberosanone and (-)-suberosenol A are reaching the picomolar cytotoxicity level on human solid tumors cell lines. Due to their impressive cytotoxic properties and their limited availability, we undertook an asymmetric synthesis of the most active members of this family in order to get insight into their absolute configurations and their biological properties. The challenge of their synthesis is the regio- and stereoselective elaboration of the compact bridged tricyclic skeleton with up to five all adjacent asymmetric centers, including a central quaternary carbon one. Our strategy is based on an aza-ene-synthesis key step which is regio-and stereo-controlled by the choice of a chiral amine enantiomer. it approach is concise and flexible, the enantiopur ABC tricyclic intermediate that have been synthesized being the common precursor of suberosanes.

Keywords: suberosanes, asymmetric synthesis, sesquiterpenes, quadranes

Procedia PDF Downloads 50

Authors: Parthiban S. R.

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Spiral heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. An innovative spiral heat exchanger based on polymer materials is designed for waste heat recovery process. Such a design based on polymer film technology provides better corrosion and chemical resistance compared to conventional metal heat exchangers. Due to the smooth surface of polymer film fouling is reduced. A new arrangement for flow of hot flue gas and cold fluid is employed for design, flue gas flows in axial path while the cold fluid flows in a spiral path. Heat load recovery achieved with the presented heat exchanger is in the range of 1.5 kW thermic but potential heat recovery about 3.5 kW might be achievable. To measure the performance of the spiral tube heat exchanger, its model is suitably designed and fabricated so as to perform experimental tests. The paper gives analysis of spiral tube heat exchanger.

Keywords: spiral heat exchanger, polymer based materials, fouling factor, heat load

Procedia PDF Downloads 362

Authors: Qaisar Fraz, H. M. Jafar, Mojeeb Bin Ihsan

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This paper presents simulation and experimen-tal results for wide band U-shaped side slots loaded linearly polarized rectangular microstrip antenna with broad side radiation characteristics suitable for onboard applications. The structure has been evolved in rugged and compact form to make it suitable for on-board applications. In addition to U-shaped central slot, pair of parallel narrow slots has been embedded close to non-radiating edges. The size and shape of these side slots have been optimized to improve the matching at upper frequency of the band. The impedance bandwidth of 34.8% as compared to 2-5% bandwidth of conventional microstrip antenna has been achieved. The frequency ratio of the two well-matched operating sections is found to be f2 / f1=1.33. The experimental results are in good agreement with the numerical results.

Keywords: low profile antennas, u-slot antennas, broad band antennas, broad-side radiation pattern, high gain antennas

Procedia PDF Downloads 347

Authors: M. Zulfiker Mahmud, M. Naimur Rahman, Farhad Bin Ashraf, Norbahiah Misran, Mohammad Tariqul Islam

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This study proposes a diamond-shaped microstrip patch antenna for ultra-wideband applications. The antenna is made up of a diamond shape radiating patch, partial ground plane, and three asterisk-shaped parasitic elements. The parasitic elements are positioned above the ground plane to enhance the bandwidth and gain. The proposed antenna has a compact dimension of 30 x 25 x 1.6 mm3 and achieves an overall bandwidth (S11<-10dB) is 5.8 GHz from 2.7 GHz to 8.5 GHz. The antenna attains more than 4 dBi realized the gain and 80% efficiency over the bandwidth with omnidirectional radiation pattern. The design and simulation of the proposed antenna are performed in Computer Simulation Technology (CST) Microwave Studio. The observation during the analysis of the simulated data reveals that the proposed antenna is suitable for Ultra wide-band (UWB) applications where high gain is required.

Keywords: diamond-shaped antenna, microstrip antenna, parasitic resonator, UWB applications

Procedia PDF Downloads 191

Authors: Philip Rose, Markus Linke, David Busquets

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The distinction between interlaminar and intralaminar fracture toughness has already been investigated by several authors. For loading mode I, the double cantilever beam specimens were often used for the interlaminar fracture toughness and the compact tension specimen for the intralaminar fracture toughness. In order to minimize the influence of the different specimen geometries, a method was developed which allows the determination of both the interlaminar and the intralaminar fracture toughness on an almost identical specimen geometry. However, as this method is not applicable to prepreg semi-finished products, a further modification was developed, which is also suitable for prepreg laminates. After the successful application for the investigation of mode I with this method, the application of the method for loading mode II is presented in this paper. In addition to manufacturing differences, due to an additional fiber ply in which the controlled crack growth takes place, the adapted test procedure is also explained. By comparing the test results of standardized end-notched flexure (ENF) specimens with those of the modified ENF specimen, the difference between the interlaminar and intralaminar fracture toughness of the material Hexply 8552/IM7 is shown.

Keywords: ENF, fracture toughness, interlaminar, mode II

Procedia PDF Downloads 105

Authors: Francky Fouedjio

Abstract:

Multivariate geostatistical data have become omnipresent in the geosciences and pose substantial analysis challenges. One of them is the grouping of data locations into spatially contiguous clusters so that data locations within the same cluster are more similar while clusters are different from each other, in some sense. Spatially contiguous clusters can significantly improve the interpretation that turns the resulting clusters into meaningful geographical subregions. In this paper, we develop an agglomerative hierarchical clustering approach that takes into account the spatial dependency between observations. It relies on a dissimilarity matrix built from a non-parametric kernel estimator of the spatial dependence structure of data. It integrates existing methods to find the optimal cluster number and to evaluate the contribution of variables to the clustering. The capability of the proposed approach to provide spatially compact, connected and meaningful clusters is assessed using bivariate synthetic dataset and multivariate geochemical dataset. The proposed clustering method gives satisfactory results compared to other similar geostatistical clustering methods.

Keywords: clustering, geostatistics, multivariate data, non-parametric

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Authors: S. V. Patil , S. K. Sahoo, K. Y. Chougule, S. S. Patil

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Spherically agglomerated crystals of Pioglitazone hydrochloride (PGH) with improved flowability and compactibility were successfully prepared by emulsion solvent diffusion method. Plane agglomerates and agglomerates with additives: polyethylene glycol 6000 (PEG), polyvinyl pyrrolidone (PVP) and β cyclodextrin (β-CD) were prepared using methanol, chloroform and water as good solvent, bridging liquid and poor solvent respectively. Particle size, flowability, compactibility and packability of plane, PEG and β-CD agglomerates were preferably improved for direct tableting compared with raw crystals and PVP agglomerates of PGH. These improved properties of spherically agglomerated crystals were due to their large and spherical shape and enhanced fragmentation during compaction which was well supported by increased tensile strength and less elastic recovery of its compact. X-ray powder diffraction and differential scanning calorimetry study were indicated polymorphic transition of PGH from form II to I during recrystallization but not associated with chemical transition indicated by fourier transforms infrared spectra.

Keywords: spherical crystallization, pioglitazone hydrochloride, compactibility, packability

Procedia PDF Downloads 323

Authors: Taehyun Kim, Hyunjoo Park, Taehyun Kim

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Since the rapid economic development, Korea has recently entered a period of low growth due to population decline and aging. Due to the urbanization around the metropolitan area and the hollowing of local cities, the ecological capacity of a city is decreasing while ecological footprints are increasing, requiring a compact space plan for maintaining urban functions. The purpose of this study is to analyze the relationship between urban spatial structure and residents' ecological footprints for sustainable spatial planning. To do this, we try to analyze the relationship between intra-urban spatial structure, such as net/gross density and service accessibility, and resident ecological footprints of food, housing, transportation, goods and services through survey and structural equation modeling. The results of the study will be useful in establishing an implementation plan for sustainable development goals (SDGs), especially for sustainable cities and communities (SDG 11) and responsible consumption and production (SDG 12) in the future.

Keywords: ecological footprint, structural equation modeling, survey, sustainability, urban spatial structure

Procedia PDF Downloads 237

Authors: Dmitriy Kuptsov

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Tree data structures, such as binary or in general k-ary trees, are essential in computer science. The applications of these data structures can range from data search and retrieval to sorting and ranking algorithms. Naive implementations of these data structures can consume prohibitively large volumes of random access memory limiting their applicability in certain solutions. Thus, in these cases, more advanced representation of these data structures is essential. In this paper we present the design of the compact version of ternary tree data structure and demonstrate the results for the experimental evaluation using static dictionary problem. We compare these results with the results for binary and regular ternary trees. The conducted evaluation study shows that our design, in the best case, consumes up to 12 times less memory (for the dictionary used in our experimental evaluation) than a regular ternary tree and in certain configuration shows performance comparable to regular ternary trees. We have evaluated the performance of the algorithms using both 32 and 64 bit operating systems.

Keywords: algorithms, data structures, succinct ternary tree, per- formance evaluation

Procedia PDF Downloads 137

Authors: S. Cheragh Dar, M. Saljooghi, A. Babrgir

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In the last couple of decades researchers' attitudes were focused on developing and enhancing heat transfer processes by using new components or cellular solids that divide into stochastic structures and periodic structures. Open-cell metal foams are part of stochastic structures families that they can be considered as an avant-garde technology and they have unique properties, this porous media can have tremendous achievements in thermal processes. This paper argues and surveys postulating possible in industrial thermal issues which include: compact electronic cooling, heat exchanger, aerospace, fines, turbo machinery, automobiles, crygen tanks, biomechanics, high temperature filters and etc. Recently, by surveying exponential rate of publications in thermal open-cell metal foams, all can be demonstrated in a holistic view which can lead researchers to a new level of understanding in different industrial thermal sections.

Keywords: heat transfer, industrial thermal, cellular solids, open cell metal foam

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Authors: Shrinivas P. Mahajan, Aarti C. Kshirsagar

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Wireless communication technology is rapidly changing with recent developments in portable devices and communication protocols. This has generated demand for more advanced and compact antenna structures and therefore, proposed work focuses on Meander Line Antenna (MLA) design. Here, Pentaband MLA is designed on a FR4 substrate (85 mm x 40 mm) with dielectric constant (ϵr) 4.4, loss tangent (tan ) 0.018 and height 1.6 mm with coplanar feed and open stub structure. It can be operated in LTE (0.670 GHz-0.696 GHz) GPS (1.564 GHz-1.579 GHz), WCDMA (1.920 GHz-2.135 GHz), LTE UL frequency band 23 (2-2.020 GHz) and 5G (3.10 GHz-3.550 GHz) application bands. Also, it gives good performance in terms of Return Loss (RL) which is < -10 dB, impedance bandwidth with maximum Bandwidth (BW) up to 0.21 GHz and realized gains with maximum gain up to 3.28 dBi. Antenna is simulated with open stub and without open stub structures to see the effect on impedance BW coverage. In addition to this, it is checked with human hand and head phantoms to assure that it falls within specified Specific Absorption Rate (SAR) limits.

Keywords: coplanar feed, L shaped ground, Meander Line Antenna, MLA, Phantom, Specific Absorption Rate, SAR

Procedia PDF Downloads 113

Authors: Isao Tomita

Abstract:

The detection of environmental gases, 12CO_2, 13CO_2, and CH_4, using near-infrared semiconductor lasers with a short laser path length is studied by means of wavelength-modulation spectroscopy. The developed system is compact and has high sensitivity enough to detect the absorption peaks of isotopic 13CO_2 of a 3-% CO_2 gas at 2 um with a path length of 2.4 m, where its peak size is two orders of magnitude smaller than that of the ordinary 12CO_2 peaks. In addition, the detection of 12CO_2 peaks of a 385-ppm (0.0385-%) CO_2 gas in the air is made at 2 um with a path length of 1.4 m. Furthermore, in pursuing the detection of an ancient environmental CH_4 gas confined to a bubble in ice at the polar regions, measurements of the absorption spectrum for a trace gas of CH_4 in a small area are attempted. For a 100-% CH_4 gas trapped in a 1 mm^3 glass container, the absorption peaks of CH_4 are obtained at 1.65 um with a path length of 3 mm, and also the gas pressure is extrapolated from the measured data.

Keywords: environmental gases, Near-Infrared Laser Detection, Wavelength-Modulation Spectroscopy, gas pressure

Procedia PDF Downloads 392

Authors: G. Voicu, C. D. Ghitulica, A. Cucuruz, C. Busuioc

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In the field of tissue engineering, the compositional and microstructural features of the employed materials play an important role, with implications on the mechanical and biological behaviour of the medical devices. In this context, the development of calcium phosphate-natural biopolymer composites represents a choice of many scientific groups. Thus, tricalcium phosphate powders were synthesized by a wet method, namely co-precipitation, starting from high purity reagents. Moreover, the substitution of calcium with magnesium have been approached, in the 5-10 wt.% range. Afterwards, the phosphate powders were integrated into two types of composites with chitosan, different from morphological point of view. First, 3D porous scaffolds were obtained by a freeze-drying procedure. Second, uniform compact films were achieved by film casting. The influence of chitosan molecular weight (low, medium and high), as well as phosphate powder to polymer ratio (1:1 and 1:2) on the morphological properties, were analysed in detail. In conclusion, the reported biocomposites, prepared by a straightforward route are suitable for bone substitution or repairing applications.

Keywords: bone reconstruction, chitosan, composite scaffolds, tricalcium phosphate

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