Search results for: compact antennas

Authors: Zhihong Luo, Guangbin Zhu, Lulu Guo, Zhujun Lyu, Kun Luo

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Cycling life has become the threshold for the prospective application of Li-O₂ batteries, and the protection of Li anode has recently regarded as the key factor to the performance. Herein, a simple low rate pre-activation (20 cycles at 0.5 Ag⁻¹ and a capacity of 200 mAh g⁻¹) was employed to effectively improve the performance and cyclability of Li-O₂ batteries. The charge/discharge cycles at 1 A g⁻¹ with a capacity of 1000 mAh g⁻¹ were maintained for up to 290 times versus 55 times for the cell without pre-activation. The ultimate battery capacity and high rate discharge property were also largely enhanced. Morphology, XRD and XPS analyses reveal that the performance improvement is in close association with the formation of the smooth and compact surface layer formed on the Li anode after low rate pre-activation, which apparently alleviated the corrosion of Li anode and the passivation of cathode during battery cycling, and the corresponding mechanism was also discussed.

Keywords: lithium oxygen battery, pre-activation, cyclability, capacity

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Authors: Can Mungan, Gokhan Kilic

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Structural engineers and tunnel owners have good reason to attach importance to the assessment and inspection of tunnels. Regular inspection is necessary to maintain and monitor the health of the structure not only at the present time but throughout its life cycle. Detection of flaws within the structure, such as corrosion and the formation of cracks within the internal elements of the structure, can go a long way to ensuring that the structure maintains its integrity over the course of its life. Other issues that may be detected earlier through regular assessment include tunnel surface delamination and the corrosion of the rebar. One advantage of new technology such as the ground penetrating radar (GPR) is the early detection of imperfections. This study will aim to discuss and present the effectiveness of GPR as a tool for assessing the structural integrity of the heavily used tunnel. GPR is used with various antennae in frequency and application method (2 GHz and 500 MHz GPR antennae). The paper will attempt to produce a greater understanding of structural defects and identify the correct tool for such purposes. Conquest View with 3D scanning capabilities was involved throughout the analysis, reporting, and interpretation of the results. This study will illustrate GPR mapping and its effectiveness in providing information of value when it comes to rebar position (lower and upper reinforcement). It will also show how such techniques can detect structural features that would otherwise remain unseen, as well as moisture ingress.

Keywords: tunnel, GPR, health monitoring, moisture ingress, rebar position

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Authors: Phanumas Khumsat, Chalermchai Janmane

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Low-voltage instrumentation amplifier has been proposed for 3-lead electrocardiogram measurement system. The circuit’s interference rejection technique is based upon common-mode feed-forwarding where common-mode currents have cancelled each other at the output nodes. The common-mode current for cancellation is generated by means of common-mode sensing and emitter or source followers with resistors employing only one transistor. Simultaneously this particular transistor also provides common-mode feedback to the patient’s right/left leg to further reduce interference entering the amplifier. The proposed designs have been verified with simulations in 0.18-µm CMOS process operating under 1.0-V supply with CMRR greater than 80dB. Moreover ECG signals have experimentally recorded with the proposed instrumentation amplifiers implemented from discrete BJT (BC547, BC558) and MOSFET (ALD1106, ALD1107) transistors working with 1.5-V supply.

Keywords: electrocardiogram, common-mode feedback, common-mode feedforward, communication engineering

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Authors: Abdalla Mohamed Eblabla

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Due to the high increase and demand for a wide assortment of applications that require low-cost, high-efficiency, and compact systems, RF power amplifiers are considered the most critical design blocks and power consuming components in wireless communication, TV transmission, radar, and RF heating. Therefore, much research has been carried out in order to improve the performance of power amplifiers. Classes-A, B, C, D, E, and F are the main techniques for realizing power amplifiers. An implementation of high efficiency class-F power amplifier with Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) was realized in this paper. The simulation and optimization of the class-F power amplifier circuit model was undertaken using Agilent’s Advanced Design system (ADS). The circuit was designed using lumped elements.

Keywords: Power Amplifier (PA), gallium nitride (GaN), Agilent’s Advanced Design System (ADS), lumped elements

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Authors: Caio Fialho

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The automobile incentive policy in Brazil since the 1950s creates several problems in its cities, more visible in large centers such as São Paulo or Rio de Janeiro, but also strongly present in smaller cities, resulting in an increase in social and spatial inequality, together with a drop in the quality of life. The analyzed city, Campo Mourão, reflects these policies, a city that initially planned to be compact and walkable took other directions and currently suffers from urban mobility and social inequality in this urban environment, despite being a medium-sized city in Brazil. The research aims to understand and diagnose how these policies shaped the city and what are the results in Brazilian's inland cities. Based on historical, bibliographical, and field research in the city, the result is a diagnosis of the problem faced and how it can be reversed in search of social equality and better quality of life.

Keywords: urban mobility, quality of life, social equality, substantiable

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Authors: Yasin Akgul, Fazil Husem, Memis Isik

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In this study, effect of content of chromium (III) oxide on production of Al/Cr203 alloys were investigated. Experimental procedure was started with mixturing of powders in the presence of absolute ethanol, vacuum distillation technique was used for evaporation, by ultrasonic bath and mechanic stirrer. Pressing procedure was achieved by hydrolic press that has 100 tons forcing for production of 25 mm diameter compact green billets. Green bodies were sintered at 600 °C in argon atmosphere. Scanning electron microscope (SEM) analysis for characterization of microstructure, compression test for determination of strength and Vickers test for measuring of hardness of sintered billets were done. End of the study is concluded that, enhancement of physical and mechanical properties is observed by increasing content of chromium (III) oxide.

Keywords: aluminium, chromium (III) oxide, powder metallurgy, sintering

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Authors: Aziz Ibrahim Abdulla, Omar Mohanad Mahdi

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The objective of this paper is to explore the effect of incorporating Nano-Silica with Silica-fume in ferrocement mortar to enhancing mechanical properties of it. One type of Nano silica with average diameter size 23nm and silica fume have been used with two percentage (1%, 2% Nano silica and 5%, 10% silica fume per weight of cement) and w/c with / without superplasticizer was been calculated by flow test method. Also three sand: cement ratios have been used (1.5, 2.0 and 2.5) with max. Aggregate size 0.6mm in this study for reference and other mixtures. Results reveal adding Nano silica with silica fume to ferrocement mortar enhances its physical and mechanical properties such as compressive strength and flexural strength. The SEM pictures and density with absorption ratio demonstrate that Nano silica with silica fume contributes to enhancement of mortar through yielding denser, more compact and uniform mixtures.

Keywords: nano silica, ferrocement mortar, compresion strength, flexural strength

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Authors: Neeraj G. Nahata, K. S. Bhagat

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Microstrip patch antenna widely used in communication area because it offers low profile, narrow bandwidth, high gain, and compact in size. It has big disadvantage of narrow bandwidth. To improve the bandwidth a W-slot technique is used, it is efficient to enhance the bandwidth of antenna. The feeding point of antenna is very important for efficient operation, so coaxial feeding technique is applied to microstrip patch antenna for impedance matching. A broadband W-slot microstrip patch antenna is designed successfully which attains a bandwidth of 22.74% at 10dB return loss with centre frequency of 4.5GHz and also it attains maximum directivity 8.78dBi. It is designed by cutting a W-slot into the patch of antenna, because of this resonant slot, the antenna gives broad bandwidth. This antenna is best suitable for C-band frequency spectrum. The proposed antenna is designed and simulated using IE3D software.

Keywords: broadband, microstrip antenna, VSWR, W-slotted patch

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Authors: A. Attaf A., I. Bouhaf Kharkhachi

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Spray ultrasonic deposition technique of tin disulfide (SnS2) thin films know wide application due to their adequate physicochemical properties for microelectronic applications and especially for solar cells. SnS2 film was deposited by spray ultrasonic technique, on pretreated glass substrates at well-determined conditions.The effect of SnS2 concentration on different optical properties of SnS2 Thin films, such us MEB, XRD, and UV spectroscopy visible spectrum was investigated. MEB characterization technique shows that the morphology of this films is uniform, compact and granular. x-ray diffraction study detects the best growth crystallinity in hexagonal structure with preferential plan (001). The results of UV spectroscopy visible spectrum show that films deposited at 0.1 mol/l is large transmittance greater than 25% in the visible region.The band gap energy is 2.54 Ev for molarity 0.1 mol/l.

Keywords: MEB, thin disulfide, thin films, ultrasonic spray, X-Ray diffraction, UV spectroscopy visible

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Authors: Mohamed Othmani, Yassine Khlifi

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This paper presents a technique for compact three dimensional (3D) object model reconstruction using wavelet networks. It consists to transform an input surface vertices into signals,and uses wavelet network parameters for signal approximations. To prove this, we use a wavelet network architecture founded on several mother wavelet families. POLYnomials WindOwed with Gaussians (POLYWOG) wavelet families are used to maximize the probability to select the best wavelets which ensure the good generalization of the network. To achieve a better reconstruction, the network is trained several iterations to optimize the wavelet network parameters until the error criterion is small enough. Experimental results will shown that our proposed technique can effectively reconstruct an irregular 3D object models when using the optimized wavelet network parameters. We will prove that an accurateness reconstruction depends on the best choice of the mother wavelets.

Keywords: 3d object, optimization, parametrization, polywog wavelets, reconstruction, wavelet networks

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Authors: Amira Dhokar, Lobna Hlaoua, Lotfi Ben Romdhane

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Tweet contextualization (TC) is a new issue that aims to answer questions of the form 'What is this tweet about?' The idea of this task was imagined as an extension of a previous area called multi-document summarization (MDS), which consists in generating a summary from many sources. In both TC and MDS, the summary should ideally contain the most relevant information of the topic that is being discussed in the source texts (for MDS) and related to the query (for TC). Furthermore of being informative, a summary should be coherent, i.e. well written to be readable and grammatically compact. Hence, coherence is an essential characteristic in order to produce comprehensible texts. In this paper, we propose a new approach to improve readability and coherence for tweet contextualization based on bipartite graphs. The main idea of our proposed method is to reorder sentences in a given paragraph by combining most expressive words detection and HITS (Hyperlink-Induced Topic Search) algorithm to make up a coherent context.

Keywords: bipartite graphs, readability, summarization, tweet contextualization

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Authors: D. R. Ambika, K. R. Radhika, D. Seshachalam

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Unconstrained authentication is an important component for personal automated systems and human-computer interfaces. Existing solutions mostly use face as the primary object of analysis. The performance of face-based systems is largely determined by the extent of deformation caused in the facial region and amount of useful information available in occluded face images. Periocular region is a useful portion of face with discriminative ability coupled with resistance to deformation. A reliable portion of periocular area is available for occluded images. The present work demonstrates that joint representation of periocular texture and periocular structure provides an effective expression and poses invariant representation. The proposed methodology provides an effective and compact description of periocular texture and shape. The method is tested over four benchmark datasets exhibiting varied acquisition conditions.

Keywords: periocular authentication, Zernike moments, LBP variance, shape and texture fusion

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Authors: Christer Frennfelt

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Solar heating is the most environmentally friendly way to heat water. Brazed Plate Heat Exchangers (BPHEs) are a key component in many solar heating applications for harvesting solar energy into accumulator tanks, producing hot tap water, and heating pools. The combination of high capacity in a compact format, efficient heat transfer, and fast response makes the BPHE the ideal heat exchanger for solar thermal systems. Solar heating is common as a standalone heat source, and as an add-on heat source for boilers, heat pumps, or district heating systems. An accumulator provides the possibility to store heat, which enables combination of different heat sources to a larger extent. In turn this works as protection to reduced access to energy or increased energy prices. For example heat from solar panels is preferably stored during the day for use at night.

Keywords: district heating and cooling, thermal storage, brazed plate heat exchanger, solar domestic hot water and combisystems

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Authors: Gennady M. Kulikov, Svetlana V. Plotnikova

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This paper focuses on implementation of the sampling surfaces (SaS) method for the three-dimensional (3D) stress analysis of functionally graded (FG) laminated elastic and piezoelectric shells. The SaS formulation is based on choosing inside the nth layer In not equally spaced SaS parallel to the middle surface of the shell in order to introduce the electric potentials and displacements of these surfaces as basic shell variables. Such choice of unknowns permits the presentation of the proposed FG piezoelectric shell formulation in a very compact form. The SaS are located inside each layer at Chebyshev polynomial nodes that improves the convergence of the SaS method significantly. As a result, the SaS formulation can be applied efficiently to 3D solutions for FG piezoelectric laminated shells, which asymptotically approach the exact solutions of piezoelectricity as the number of SaS In goes to infinity.

Keywords: electroelasticity, functionally graded material, laminated piezoelectric shell, sampling surfaces method

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Authors: Chuanzhi Chen, Wenjing Yu

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Parabolic cylindrical deployable antenna has the characteristics of wide cutting width, strong directivity, high gain, and easy automatic beam scanning. While, due to its large size, high flexibility, and strong coupling, the deployment process of parabolic cylindrical deployable antenna presents such problems as unsynchronized deployment speed, large local deformation and discontinuous switching of deployment state. A large deployable parabolic cylindrical antenna is taken as the research object, and the problem of unfolding process instability of cylindrical antenna is studied in the paper, which is caused by multiple factors such as multiple closed loops, elastic deformation, motion friction, and gap collision. Firstly, the multi-flexible system dynamics model of large-scale parabolic cylindrical antenna is established to study the influence of friction and elastic deformation on the stability of large multi-closed loop antenna. Secondly, the evaluation method of antenna expansion stability is studied, and the quantitative index of antenna configuration design is proposed to provide a theoretical basis for improving the overall performance of the antenna. Finally, through simulation analysis and experiment, the development dynamics and stability of large-scale parabolic cylindrical antennas are verified by in-depth analysis, and the principles for improving the stability of antenna deployment are summarized.

Keywords: multibody dynamics, expandable parabolic cylindrical antenna, stability, flexible deformation

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Authors: Keita Iwai, Isao Tomita

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To expand the optical spectrum for use in broadband optical communications, we study the properties of a semiconductor waveguide device with a tapered structure including its third-order optical nonlinearity. Spectral-broadened output by the tapered structure has the potential to create a compact, built-in device for optical communications. Here we deal with a compound semiconductor waveguide, the material of which is the same as that of laser diodes used in the communication systems, i.e., InₓGa₁₋ₓAsᵧP₁₋ᵧ, which has large optical nonlinearity. We confirm that our structure widens the output spectrum sufficiently by controlling its taper form factor while utilizing the large nonlinear refraction of InₓGa₁₋ₓAsᵧP₁₋ᵧ. We also examine the taper effect for nonlinear optical loss.

Keywords: InₓGa₁₋ₓAsᵧP₁₋ᵧ, waveguide, nonlinear refraction, spectral spreading, taper device

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Authors: M. Debieche, F. Kaoua

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This paper deals with the use two locals materials abundant in our country, with the view to use a mixture in the waterproofing the landfills. Our interest comes from the necessity to the environment protection, which has recently considerably grown. The site's waterproofing technique, in the landfills sites, is nowadays a very necessary condition to protect the environment, which requires the use of appropriate materials. To this end, an optimal mixture ensuring good performance in terms of hydraulic conductivity, durability and shear strength, mixtures based of sand at different concentrations of sodium bentonite, at compact state are prepared and studied. This study showed that a low permeability of mixture (sand / bentonite) can be achieved 6% of sodium bentonite. This mixture confers also good mechanical behavior, expressed by the recorded, reduction of friction (φ) and the increase of the cohesion (C). Thus, the selected formulation represents an optimal mixture for waterproofing systems. It guarantees an economical and ecological advantages.

Keywords: hydraulic conductivity, sand, sodium bentonite, sustainability

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Authors: S. Nouri

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In this study, the Si-aluminide coating was prepared on gamma-TiAl [Ti-45Al-2Nb-2Mn-1B (at. %)] via liquid-phase slurry procedure. The high temperature oxidation resistance of this diffusion coating was evaluated at 1100 °C for 400 hours. The results of the isothermal oxidation showed that the formation of Si-aluminide coating can remarkably improve the high temperature oxidation of bare gamma-TiAl alloy. The identification of oxide scale microstructure showed that the formation of protective Al₂O₃+SiO₂ mixed oxide scale along with a continuous, compact and uniform layer of Ti₅Si₃ beneath the surface oxide scale can act as an oxygen diffusion barrier during the high temperature oxidation. The other possible mechanisms related to the formation of Si-aluminide coating and oxide scales were also discussed.

Keywords: Gamma-TiAl alloy, high temperature oxidation, Si-aluminide coating, slurry procedure

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Authors: M. Naimur Rahman, Mohammad Tariqul Islam, Mandeep Singh Jit Singh, Norbahiah Misran

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This paper presents the architecture and exploration of a compact, circulated double Psi-shaped microstrip patch antenna for Ku-band satellite applications. The antenna is composed of the double Psi-shaped patch in opposite focus which is circulated with a ring. The antenna size is 24 mm × 18 mm and the prototype is imprinted on Rogers RT/duroid 5880 materials with the depth of 1.57 mm. The substrate has a relative permittivity of 2.2 and the dielectric constant of 0.0009. The excitation is supplied through a 50Ω microstrip line. The performance of the presented antenna has been simulated and verified with the High-Frequency Structural Simulator (HFSS). The results depict that the antenna covers the frequency spectrum 14.6 - 17.4 GHz (Ku-band) with 10 dB return loss. The antenna has a 4.40 dBi maximum gain with stable radiation patterns throughout the operating band which makes the proposed antenna compatible for the satellite application in Ku-band.

Keywords: Ku-band antenna, microstrip antenna, psi-shaped antenna, satellite applications

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Authors: Dimitrios J. Dimitriou

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It is widely recognised that the assets portfolio development is helping to enhance economic growth, productivity and competitiveness. While numerous studies and reports certify the positive effect of investments in large infrastructure investments on the local economy, still, the methodology to estimate the contribution in economic development is a challenging issue for researchers and economists. The key question is how to estimate those economic impacts in each economic system. This paper provides a compact and applicable methodological framework providing quantitative results in terms of the overall jobs and income generated into the project life cycle. According to a deterministic mathematical approach, the key variables and the modelling framework are presented. The numerical case study highlights key results for a new motorway project in Greece, which is experienced economic stress for many years, providing the opportunity for comparisons with similar cases.

Keywords: quantitative modelling, economic impact, large transport infrastructure, economic assessment

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Authors: M. Y. Ismail, Arslan Kiyani

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Narrow bandwidth and high loss performance limits the use of reflectarray antennas in some applications. This article reports on the feasibility of employing strategic reflectarray resonant elements to characterize the reflectivity performance of reflectarrays in X-band frequency range. Strategic reflectarray resonant elements incorporating variable substrate thicknesses ranging from 0.016λ to 0.052λ have been analyzed in terms of reflection loss and reflection phase performance. The effect of substrate thickness has been validated by using waveguide scattering parameter technique. It has been demonstrated that as the substrate thickness is increased from 0.508mm to 1.57mm the measured reflection loss of dipole element decreased from 5.66dB to 3.70dB with increment in 10% bandwidth of 39MHz to 64MHz. Similarly the measured reflection loss of triangular loop element is decreased from 20.25dB to 7.02dB with an increment in 10% bandwidth of 12MHz to 23MHz. The results also show a significant decrease in the slope of reflection phase curve as well. A Figure of Merit (FoM) has also been defined for the comparison of static phase range of resonant elements under consideration. Moreover, a novel numerical model based on analytical equations has been established incorporating the material properties of dielectric substrate and electrical properties of different reflectarray resonant elements to obtain the progressive phase distribution for each individual reflectarray resonant element.

Keywords: numerical model, reflectarray resonant elements, scattering parameter measurements, variable substrate thickness

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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

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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

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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

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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

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Authors: Yih-Chien Chen, Yue-Xuan Du, Min-Zhe Weng

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Carbon monoxide is a substance produced by the incomplete combustion. It is toxic even at concentrations of less than 100ppm. Since it is colorless and odorless, it is difficult to detect. CO sensors have been developed using a variety of physical mechanisms, including semiconductor oxides, solid electrolytes, and organic semiconductors. Many works have focused on using semiconducting sensors composed of sensitive layers such as ZnO, TiO₂, and NiO with high sensitivity for gases. However, these sensors working at high temperatures increased their power consumption. On the other hand, the dielectric resonator (DR) is attractive for gas detection due to its large surface area and sensitivity for external environments. Materials that are to be employed in sensing devices must have a high-quality factor. Numerous researches into the fergusonite-type structure and related ceramic systems have explored. Extensive research into RENbO₄ ceramics has explored their potential application in resonators, filters, and antennas in modern communication systems, which are operated at microwave frequencies. Nd(Ti₀.₅W₀.₅)O₄ ceramics were synthesized herein using the conventional mixed-oxide method. The Nd(Ti₀.₅W₀.₅)O₄ ceramics were prepared using the conventional solid-state method. Dielectric constants (εᵣ) of 15.4-19.4 and quality factor (Q×f) of 3,600-11,100 GHz were obtained at sintering temperatures in the range 1425-1525°C for 4 h. The dielectric properties of the Nd(Ti₀.₅W₀.₅)O₄ ceramics at microwave frequencies were found to vary with the sintering temperature. For a further understanding of these microwave dielectric properties, they were analyzed by densification, X-ray diffraction (XRD), and by making microstructural observations.

Keywords: dielectric constant, dielectric resonators, sensors, quality factor

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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

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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

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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

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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

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