Search results for: vertical electrical sounding

Authors: Yu Zhao, Shinsuke Kato, Jianing Zhao

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Particles exhausted from cars have an adverse impacts on human health. The study developed a three-dimensional particle dispersion numerical model including particle coagulation to simulate the particle concentration distribution under idling conditions in a residential underground garage. The simulation results demonstrate that particle disperses much faster in the vertical direction than that in horizontal direction. The enhancement of particle dispersion in the vertical direction due to the increase of cars with engine running is much stronger than that in the car exhaust direction. Particle dispersion from each pair of adjacent cars has little influence on each other in the study. Average particle concentration after 120 seconds exhaust is 1.8-4.5 times higher than the initial total particles at ambient environment. Particle pollution in the residential underground garage is severe.

Keywords: dispersion, idling conditions, particle concentration, residential underground garage

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Authors: Y. Laib Dit Leksir, S. Bouhouche

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Analysis and processing of data bases resulting from infrared thermal measurements made on the electrical installation requires the development of new tools in order to obtain correct and additional information to the visual inspections. Consequently, the methods based on the capture of infrared digital images show a great potential and are employed increasingly in various fields. Although, there is an enormous need for the development of effective techniques to analyse these data base in order to extract relevant information relating to the state of the equipments. Our goal consists in introducing recent techniques of modeling based on new methods, image and signal processing to develop mathematical models in this field. The aim of this work is to capture the anomalies existing in electrical equipments during an inspection of some machines using A40 Flir camera. After, we use binarisation techniques in order to select the region of interest and we make comparison between these methods of thermal images obtained to choose the best one.

Keywords: infrared thermography, defect detection, troubleshooting, electrical equipment

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Authors: Sung-Won Seo, Jang-Young Choi

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The rare earth magnets used in synchronous generators offer many advantages, including high efficiency, greatly reduced the size, and weight. The permanent magnet linear synchronous generator (PMLSG) allows for direct drive without the need for a mechanical device. Therefore, the PMLSG is well suited to translational applications, such as wave energy converters and free piston energy converters. This manuscript compares the effects of different magnetization patterns on the characteristics of double-sided PMLSGs in slotless stator structures. The Halbach array has a higher flux density in air-gap than the Vertical array, and the advantages of its performance and efficiency are widely known. To verify the advantage of Halbach array, we apply a finite element method (FEM) and analytical method. In general, a FEM and an analytical method are used in the electromagnetic analysis for determining model characteristics, and the FEM is preferable to magnetic field analysis. However, the FEM is often slow and inflexible. On the other hand, the analytical method requires little time and produces accurate analysis of the magnetic field. Therefore, the flux density in air-gap and the Back-EMF can be obtained by FEM. In addition, the results from the analytical method correspond well with the FEM results. The model of the Halbach array reveals less copper loss than the model of the Vertical array, because of the Halbach array’s high output power density. The model of the Vertical array is lower core loss than the model of Halbach array, because of the lower flux density in air-gap. Therefore, the current density in the Vertical model is higher for identical power output. The completed manuscript will include the magnetic field characteristics and structural features of both models, comparing various results, and specific comparative analysis will be presented for the determination of the best model for application in a wave energy converting system.

Keywords: wave energy converter, permanent magnet linear synchronous generator, finite element method, analytical method

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Authors: Nasir Khalid, S. Thirumalaichelvam

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In most buildings, according to US Department of Energy Data Book, the electrical consumption attributable to centralized heating and ventilation of air- condition (HVAC) component can be as high as 40-60% of the total electricity consumption for an entire building. To provide efficient energy management for the market today, researchers are finding new ways to develop a system that can save electrical consumption of buildings even more. In this concept paper, a system known as Intelligent Chiller Energy Efficiency (iCEE) System is being developed that is capable of saving up to 25% from the chiller’s existing electrical energy consumption. In variable frequency drives (VFDs), research has found significant savings up to 30% of electrical energy consumption. Together with the VFDs at specific Air Handling Unit (AHU) of HVAC component, this system will save even more electrical energy consumption. The iCEE System is compatible with any make, model or age of centrifugal, rotary or reciprocating chiller air-conditioning systems which are electrically driven. The iCEE system uses engineering principles of efficiency analysis, enthalpy analysis, heat transfer, mathematical prediction, modified genetic algorithm, psychometrics analysis, and optimization formulation to achieve true and tangible energy savings for consumers.

Keywords: variable frequency drives, adjustable speed drives, ac drives, chiller energy system

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Authors: Oke Oktavianty, Tadayuki Kyoutani, Shigeyuki Haruyama, Junji Kaneko, Ken Kaminishi

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Modelica has many advantages and it is very useful in modeling and simulation especially for the multi-domain with a complex technical system. However, the big obstacle for a beginner is to understand the basic concept and to build a new system model for a real system. In order to understand how to solve the simple circuit model by hand translation and to get a better understanding of how modelica works, we provide a detailed explanation about solver ordering system in horizontal and vertical sorting and make some proposals for improvement. In this study, some difficulties in using modelica software with the original concept and the comparison with Finite Element Method (FEM) approach is discussed. We also present our textual modeling approach using FEM concept for acausal and causal model construction. Furthermore, simulation results are provided that demonstrate the comparison between using textual modeling with original coding in modelica and FEM concept.

Keywords: FEM, a causal model, modelica, horizontal and vertical sorting

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Authors: Chi-Yan Chu, Kai-Chi Chuang, Huang-Chung Cheng

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In this study, the RRAM devices with the TiN/Ti/HfO_x/TiN structure were fabricated, then the electrical characteristics of the devices without annealing and after 400 °C and 500 °C of the furnace annealing (FA) temperature processes were compared. The RRAM devices after the FA’s 400 °C showed the lower forming, set and reset voltages than the other devices without annealing. However, the RRAM devices after the FA’s 500 °C did not show any electrical characteristics because the TiN/Ti/HfO_x/TiN device was oxidized, as shown in the XPS analysis. From these results, the RRAM devices after the FA’s 400 °C showed the best electrical characteristics.

Keywords: RRAM, furnace annealing (FA), forming, set and reset voltages, XPS

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Authors: Ehsan Javanmardemamgheisi, Javad Mehr, Jason Ali-Lavroff, Damien Holloway, Michael Davis

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During the last decades, a growing interest in faster and more efficient waterborne transportation has led to the development of high-speed vessels for both commercial and military applications. To satisfy this global demand, a wide variety of arrangements of high-speed crafts have been proposed by designers. Among them, high-speed catamarans have proven themselves to be a suitable Roll-on/Roll-off configuration for carrying passengers and cargo due to widely spaced demi hulls, a wide deck zone, and a high ratio of deadweight to displacement. To improve passenger comfort and crew workability and enhance the operability and performance of high-speed catamarans, mitigating the severity of motions and structural loads using Ride Control Systems (RCS) is essential.In this paper, a set of towing tank tests was conducted on a 2.5 m scaled model of a 112 m Incat Tasmania high-speed catamaran in irregular head seas to investigate the effect of different ride control algorithms including linear and nonlinear versions of the heave control, pitch control, and local control on motion responses and passenger comfort of the full-scale ship. The RCS included a centre bow-fitted T-Foil and two transom-mounted stern tabs. All the experiments were conducted at the Australian Maritime College (AMC) towing tank at a model speed of 2.89 m/s (37 knots full scale), a modal period of 1.5 sec (10 sec full scale) and two significant wave heights of 60 mm and 90 mm, representing full-scale wave heights of 2.7 m and 4 m, respectively. Spectral analyses were performed using Welch’s power spectral density method on the vertical motion time records of the catamaran model to calculate heave and pitch Response Amplitude Operators (RAOs). Then, noting that passenger discomfort arises from vertical accelerations and that the vertical accelerations vary at different longitudinal locations within the passenger cabin due to the variations in amplitude and relative phase of the pitch and heave motions, the vertical accelerations were calculated at three longitudinal locations (LCG, T-Foil, and stern tabs). Finally, frequency-weighted Root Mean Square (RMS) vertical accelerations were calculated to estimate Motion Sickness Dose Value (MSDV) of the ship based on ISO 2631-recommendations. It was demonstrated that in small seas, implementing a nonlinear pitch control algorithm reduces the peak pitch motions by 41%, the vertical accelerations at the forward location by 46%, and motion sickness at the forward position by around 20% which provides great potential for further improvement in passenger comfort, crew workability, and operability of high-speed catamarans.

Keywords: high-speed catamarans, ride control system, response amplitude operators, vertical accelerations, motion sickness, irregular waves, towing tank tests.

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Authors: M. Simchi, M. Amiri, E. Rezvani, I. Mirzaei, M. Berahman, A. Simchi, M. Fardmanesh

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Graphene is a single-atomic two-dimensional crystal of carbon atoms that has considerable properties due to its unique structure and physics with applications in different fields. Graphene has sensitive electrical properties due to its atomic-thin structure. Along with the substrate materials and their influence on the transport properties in graphene, design and fabrication of graphene-based devices for biomedical and biosensor applications are challenging. In this work, large-area high-quality graphene nanosheets were prepared by low pressure chemical vapor deposition using methane gas as carbon source on copper foil and transferred on the biocompatible substrates. Through deposition of titanium and gold contacts, current-voltage response of the transferred graphene on four biocompatible substrates, including PDMS, SU-8, Nitrocellulose, and Kapton (Fig. 2) were experimentally determined. The considerable effect of the substrate type on the electrical properties of graphene is shown. The sheet resistance of graphene is changed from 0.34 to 14.5 kΩ/sq, depending on the substrate.

Keywords: biocompatible substrates, electrical properties, graphene, sheet resistance

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Authors: Abdelhammid Chibane

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This study summarizes state-of-the-art knowledge in the seismic response of vertically irregular building frames. Criteria defining vertical irregularity as per the current building codes have been discussed. A review of studies on the seismic behaviour of vertically irregular structures along with their findings has been presented. It is observed that building codes provide criteria to classify the vertically irregular structures and suggest dynamic analysis to arrive at design lateral forces. Most of the studies agree on the increase in drift demand in the tower portion of set-back structures and on the increase in seismic demand for buildings with discontinuous distributions in mass, stiffness, and strength. The largest seismic demand is found for the combined-stiffness-and-strength irregularity.

Keywords: mass irregularity, set-back structure, stiffness irregularity, strength irregularity, vertical irregularity

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Authors: Anthony Coogan

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Born’s probability interpretation of wave functions would have led to nearly identical results had he chosen a frequency interpretation instead. Logically, Born may have assumed that only one electron was under consideration, making it nonsensical to propose a frequency wave. Author’s suggestion: the actual experimental results were not of a single electron; rather, they were groups of reflected x-ray photons. The vertical waveform used by Scrhödinger in his Particle in the Box Theory makes sense if it was intended to represent a quantum leap. The author extended the single vertical panel to form a bar chart: separate panels would represent different energy levels. The proposed bar chart would be populated by reflected photons. Expansion of basic ideas: Part of Scrhödinger’s ‘Particle in the Box’ theory may be valid despite negative criticism. The waveform used in the diagram is vertical, which may seem absurd because real waves decay at a measurable rate, rather than instantaneously. However, there may be one notable exception. Supposedly, following from the theory, the Uncertainty Principle was derived – may a Quantum Leap not be represented as an instantaneous waveform? The great Scrhödinger must have had some reason to suggest a vertical waveform if the prevalent belief was that they did not exist. Complex wave forms representing a particle are usually assumed to be continuous. The actual observations made were x-ray photons, some of which had struck an electron, been reflected, and then moved toward a detector. From Born’s perspective, doing similar work the years in question 1926-7, he would also have considered a single electron – leading him to choose a probability distribution. Probability Distributions appear very similar to Frequency Distributions, but the former are considered to represent the likelihood of future events. Born’s interpretation of the results of quantum experiments led (or perhaps misled) many researchers into claiming that humans can influence events just by looking at them, e.g. collapsing complex wave functions by 'looking at the electron to see which slit it emerged from', while in reality light reflected from the electron moved in the observer’s direction after the electron had moved away. Astronomers may say that they 'look out into the universe' but are actually using logic opposed to the views of Newton and Hooke and many observers such as Romer, in that light carries information from a source or reflector to an observer, rather the reverse. Conclusion: Due to the controversial nature of these ideas, especially its implications about the nature of complex numbers used in applications in science and engineering, some time may pass before any consensus is reached.

Keywords: complex wave functions not necessary, frequency distributions instead of wave functions, information carried by light, sketch graph of uncertainty principle

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Authors: Koichi Yonemoto, Hiroshi Yamasaki, Masatomo Ichige, Yusuke Ura, Guna S. Gossamsetti, Takumi Ohki, Kento Shirakata, Ahsan R. Choudhuri, Shinji Ishimoto, Takashi Mugitani, Hiroya Asakawa, Hideaki Nanri

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This paper presents the strategic development plan of winged rockets WIRES (WInged REusable Sounding rocket) aiming at unmanned suborbital winged rocket for demonstrating future fully reusable space transportation technologies, such as aerodynamics, Navigation, Guidance and Control (NGC), composite structure, propulsion system, and cryogenic tanks etc., by universities in collaboration with government and industries, as well as the past and current flight test results.

Keywords: autonomous guidance and control, reusable rocket, space transportation system, suborbital vehicle, winged rocket

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Authors: Aynur Aker, Hasan Kaya

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In recent years, the use of the aluminum based alloys in the industry and technology are increasing. Alloying elements in aluminum have further been improving the strength and stiffness properties that provide superior compared to other metals. In this study, investigation of physical properties (microstructure, microhardness, tensile strength, electrical conductivity and thermal properties) in the Al-12.6wt.%Si-%2wt.Ni ternary alloy were investigated. Al-Si-Ni alloy was prepared in a graphite crucible under vacuum atmosphere. The samples were directionally solidified upwards with different growth rate (V) at constant temperature gradient G (7.73 K/mm). The microstructures (flake spacings, λ), microhardness (HV), ultimate tensile strength, electrical resistivity and thermal properties enthalpy of fusion and specific heat and melting temperature) of the samples were measured. Influence of the growth rate and flake spacings on microhardness, ultimate tensile strength and electrical resistivity were investigated and relationships between them were experimentally obtained by using regression analysis. According to results, λ values decrease with increasing V, but microhardness, ultimate tensile strength, electrical resistivity values increase with increasing V. Variations of electrical resistivity for cast samples with the temperature in the range of 300-1200 K were also measured by using a standard dc four-point probe technique. The enthalpy of fusion and specific heat for the same alloy was also determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from liquid to solid. The results obtained in this work were compared with the previous similar experimental results obtained for binary and ternary alloys.

Keywords: electrical resistivity, enthalpy, microhardness, solidification, tensile stress

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Authors: Zdzislaw Kaminski, Zbigniew Czyz

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The paper discusses the results of the research into a wind turbine with a vertical axis of rotation which was performed with the open return wind tunnel, Gunt HM 170, at the laboratory of the Department of Thermodynamics, Fluid Mechanics and Propulsion Aviation Systems of Lublin University of Technology. Wind tunnel experiments are a necessary step to construct any new type of wind turbine, to validate design assumptions and numerical results. This research focused on the rotor with the blades capable of modifying their working surfaces, i.e. absorbing wind kinetic energy. The operation of this rotor is based on adjusting angular aperture α of the top and bottom parts of the blades mounted on an axis. If this angle α increases, the working surface which absorbs wind kinetic energy also increases. The study was performed on scaled and geometrically similar models with the criteria of similarity relevant for the type of research preserved. The rotors with varied angular apertures of their blades were printed for the research with a powder 3D printer, ZPrinter® 450. This paper presents the research results for the selected flow speed of 6.5 m/s for the three angular apertures of the rotor blades, i.e. 30°, 60°, 90° at varied speeds. The test stand enables the turbine rotor to be braked to achieve the required speed and airflow speed and torque to be recorded. Accordingly, the torque and power as a function of airflow were plotted. The rotor with its adjustable blades enables turbine power to be adjusted within a wide range of wind speeds. A variable angular aperture of blade working surfaces α in a wind turbine enables us to control the speed of the turbine and consequently its output power. Reducing the angular aperture of working surfaces results in reduced speed, and if a special current generator applied, electrical output power is reduced, too. Speed adjusted by changing angle α enables the maximum load acting on rotor blades to be controlled. The solution under study is a kind of safety against a damage of a turbine due to possible high wind speed.

Keywords: drive torque, renewable energy, power, wind turbine, wind tunnel

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Authors: Sana Hamdi, Emna Bouazizi, Sami Faiz

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In recent years, real-time spatial applications, like location-aware services and traffic monitoring, have become more and more important. Such applications result dynamic environments where data as well as queries are continuously moving. As a result, there is a tremendous amount of real-time spatial data generated every day. The growth of the data volume seems to outspeed the advance of our computing infrastructure. For instance, in real-time spatial Big Data, users expect to receive the results of each query within a short time period without holding in account the load of the system. But with a huge amount of real-time spatial data generated, the system performance degrades rapidly especially in overload situations. To solve this problem, we propose the use of data partitioning as an optimization technique. Traditional horizontal and vertical partitioning can increase the performance of the system and simplify data management. But they remain insufficient for real-time spatial Big data; they can’t deal with real-time and stream queries efficiently. Thus, in this paper, we propose a novel data partitioning approach for real-time spatial Big data named VPA-RTSBD (Vertical Partitioning Approach for Real-Time Spatial Big data). This contribution is an implementation of the Matching algorithm for traditional vertical partitioning. We find, firstly, the optimal attribute sequence by the use of Matching algorithm. Then, we propose a new cost model used for database partitioning, for keeping the data amount of each partition more balanced limit and for providing a parallel execution guarantees for the most frequent queries. VPA-RTSBD aims to obtain a real-time partitioning scheme and deals with stream data. It improves the performance of query execution by maximizing the degree of parallel execution. This affects QoS (Quality Of Service) improvement in real-time spatial Big Data especially with a huge volume of stream data. The performance of our contribution is evaluated via simulation experiments. The results show that the proposed algorithm is both efficient and scalable, and that it outperforms comparable algorithms.

Keywords: real-time spatial big data, quality of service, vertical partitioning, horizontal partitioning, matching algorithm, hamming distance, stream query

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Authors: Jiri Primas, Michal Malik, Darina Jasikova, Michal Kotek, Vaclav Kopecky

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Authors of this paper discuss the measuring of volume ratio of two immiscible liquids in the homogenous mixture using the industrial Electrical Impedance Tomography (EIT) system ITS p2+. In the first part of the paper, the principle of EIT and the basic theory of conductivity of mixture of two components are stated. In the next part, the experiment with water and olive oil mixed with Rushton turbine is described, and the measured results are used to verify the theory. In the conclusion, the results are discussed in detail, and the accuracy of the measuring method and its advantages are also mentioned.

Keywords: conductivity, electrical impedance tomography, homogenous mixture, mixing process

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Authors: Khalid H. Abass

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Al-Ni-Cr alloy contains different ratios of Ni and Cr was prepared by mixing Al, Ni and Cr at 800oC under an argon atmosphere. The prepared alloys were heated for 1300 hr to 560oC, and then cooled rapidly by water at the ambient temperature. Surface morphology for alloys is studied by scanning electron microscope (SEM). The resultant homogeneous surface is a result of heat treatment. The X-ray diffraction patterns showed (111), (200), and (220) diffraction lines from cubic Al crystal structure, and suggested that the intensity of peak (111) orientation is predominant. Three binary phases were observed and grown in alloys: Al3Ni (Orthorhombic, a = 6.598Ǻ, b = 7.352 Ǻ, c = 4.802 Ǻ), Cr9Al17 (Rhombohedra, a = 12.910 Ǻ, c = 15.677), and Ni2Cr3 (Tetragonal, a = 8.82 Ǻ, c = 4.58 Ǻ). The average crystallite sizes of the prepared samples were found to be from 3000 to 3094 nm by SEM, which is much smaller than that estimated from XRD data. Corrosion resistance increases with increasing Ni-Cr content in Al alloys. The electrical volume resistivity decreased with increasing Ni-Cr content at low frequency. This behavior can be seen generally at 50Hz, where the electrical volume resistivity reached the value of 3.98×10-8Ω.cm for the ratio Al-1.8 at.%Ni-0.18at.%Cr.

Keywords: Al-Ni-Cr alloy, corrosion current, electrical volume resistivity, binary phase, homogeneous surface

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Authors: Seok Min Choi, Minho Bang, Seuong Yun Kim, Hyungmin Lee, Won-Gu Joo, Hyung Hee Cho

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The matrix cooling channel was used for gas turbine blade cooling passage. The matrix cooling structure is useful for the structure stability however the cooling performance of internal cooling channel was not enough for cooling. Therefore, we designed the rib configurations in the matrix cooling channel to enhance the cooling performance. The numerical simulation was conducted to analyze cooling performance of rib configured matrix cooling channel. Three different rib configurations were used which are vertical rib, angled rib and c-type rib. Three configurations were adopted in two positions of matrix cooling channel which is one fourth and three fourth of channel. The result shows that downstream rib has much higher cooling performance than upstream rib. Furthermore, the angled rib in the channel has much higher cooling performance than vertical rib. This is because; the angled rib improves the swirl effect of matrix cooling channel more effectively. The friction factor was increased with the installation of rib. However, the thermal performance was increased with the installation of rib in the matrix cooling channel.

Keywords: matrix cooling, rib, heat transfer, gas turbine

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Authors: Twin Aji Kusumagiani, Eleonora Agustine, Dini Fitriani

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The value changes of soil physical properties in the agricultural area are giving impacts on soil fertility. This can be caused by excessive usage of inorganic fertilizers and imbalances on organic fertilization. Soil physical parameters that can be measured include soil electrical conductivity, water content volume, soil porosity, dielectric permittivity, etc. This study used the electrical conductivity and volume water content as the measured physical parameters. The study was conducted on volcanic soil obtained from agricultural land conditioned with NPK fertilizer and salt in a certain amount. The dimension of the conditioned soil being used is 1 x 1 x 0.5 meters. By using this method, we can delineate the soil electrical conductivity value of land due to changes in the provision of inorganic NPK fertilizer and the salinity in the soil. Zone with the additional 1 kg of salt has the dimension of 60 cm in width, 20 cm in depth and 1 cm in thickness while zone with the additional of 10 kg NPK fertilizer has the dimensions of 70 cm in width, 20 cm in depth and 3 cm in thickness. This salt addition resulted in EC values changes from the original condition. Changes of the EC value tend to occur at a depth of 20 to 40 cm on the line 1B at 9:45 dS/cm and line 1C of 9.35 dS/cm and tend to have the direction to the Northeast.

Keywords: EC, electrical conductivity, VWC, volume water content, NPK fertilizer, salt, volcanic soil

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Authors: Ruxandra Aursulesei, David O’Callaghan, Cian Ryan, Diarmaid O’Cualain, Viktor Varkarakis, Alina Sultana, Joseph Lemley

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Human errors caused by drowsiness are among the leading causes of road accidents. Neurobiological research gives information about the electrical signals emitted by neurons firing within the brain. Electrical signal frequencies can be determined by attaching bio-sensors to the head surface. By observing the electrical impulses and the rhythmic interaction of neurons with each other, we can predict the mental state of a person. In this paper, we aim to better understand intersubject and intrasubject variability in terms of electrophysiological patterns that occur at the onset of drowsiness and their evolution with the decreasing of vigilance. The purpose is to lay the foundations for an algorithm that detects the onset of drowsiness before the physical signs become apparent.

Keywords: electroencephalography, drowsiness, ADAS, annotations, clinician

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Authors: M. R. Akbari, P. Soleimani, R. Khalili, Sara Akbari

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Analyzing and modeling the vibrational behavior of arched bridges during the earthquake in order to decrease the exerted damages to the structure is a very hard task to do. This item has been done analytically in the present paper for the first time. Due to the importance of building arched bridges as a great structure in the human being civilization and its specifications such as transferring vertical loads to its arcs and the lack of bending moments and shearing forces, this case study is devoted to this special issue. Here, the nonlinear vibration of arched bridges has been modeled and simulated by an arched beam with harmonic vertical loads and its behavior has been investigated by analyzing a nonlinear partial differential equation governing the system. It is notable that the procedure has been done analytically by AGM (Akbari, Ganji Method). Furthermore, comparisons have been made between the obtained results by numerical Method (rkf-45) and AGM in order to assess the scientific validity.

Keywords: new method (AGM), arched beam bridges, angular frequency, harmonic loads

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Authors: Jana Stepanovska, Roman Matejka, Jozef Rosina, Marta Vandrovcova, Lucie Bacakova

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The aim of this study was to develop a system for mechanical and also electrical stimulation controlling in vitro osteogenesis under conditions more similar to the in vivo bone microenvironment than traditional static cultivation, which would achieve good adhesion, growth and other specific behaviors of osteogenic cells in cultures. An engineered culture system for mechanical stimulation of the mesenchymal stem cells on the charged surface was designed. The bioreactor allows efficient mechanical loading inducing an electrical response and perfusion of the culture chamber with seeded cells. The mesenchymal stem cells were seeded to specific charged materials, like polarized hydroxyapatite (Hap) or other materials with piezoelectric and ferroelectric features, to create electrical potentials for stimulating of the cells. The material of the matrix was TiNb alloy designed for these purposes, and it was covered by BaTiO3 film, like a kind of piezoelectric material. The process of mechanical stimulation inducing electrical response is controlled by measuring electrical potential in the chamber. It was performed a series of experiments, where the cells were seeded, perfused and stimulated up to 48 hours under different conditions, especially pressure and perfusion. The analysis of the proteins expression was done, which demonstrated the effective mechanical and electrical stimulation. The experiments demonstrated effective stimulation of the cells in comparison with the static culture. This work was supported by the Ministry of Health, grant No. 15-29153A and the Grant Agency of the Czech Republic grant No. GA15-01558S.

Keywords: charged surface, dynamic cultivation, electrical stimulation, ferroelectric layers, mechanical stimulation, piezoelectric layers

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Authors: Nacera Yassa, Abdelmalek Saidoune, Ghania Ouadfel, Hamza Houassine

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The rapid advancement in electrical technologies has underscored the increasing importance of multiphase machines across various industrial sectors. These machines offer significant advantages in terms of efficiency, compactness, and reliability compared to their single-phase counterparts. However, early detection and diagnosis of electrical faults remain critical challenges to ensure the durability and safety of these complex systems. This paper presents an advanced analytical model for multiphase machines, with a particular focus on dual stator asynchronous machines. The primary objective is to develop a robust diagnostic tool capable of effectively detecting and locating electrical faults in these machines, including short circuits, winding faults, and voltage imbalances. The proposed methodology relies on an analytical approach combining electrical machine theory, modeling of magnetic and electrical circuits, and advanced signal analysis techniques. By employing detailed analytical equations, the developed model accurately simulates the behavior of multiphase machines in the presence of electrical faults. The effectiveness of the proposed model is demonstrated through a series of case studies and numerical simulations. In particular, special attention is given to analyzing the dynamic behavior of machines under different types of faults, as well as optimizing diagnostic and recovery strategies. The obtained results pave the way for new advancements in the field of multiphase machine diagnostics, with potential applications in various sectors such as automotive, aerospace, and renewable energies. By providing precise and reliable tools for early fault detection, this research contributes to improving the reliability and durability of complex electrical systems while reducing maintenance and operation costs.

Keywords: faults, diagnosis, modelling, multiphase machine

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Authors: N. Nandan A. M. Nagaraj, L. Sanjeev Kumar

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In the rapidly growing population, the requirement of electrical power is increasing day by day. In order to meet the needs, we need to generate the power using alternate method. In this paper, a presentable approach is developed by analysis and can be implemented by utilizing heat energy, which is generated in numerous ways in some of the rural areas in India. The thermoelectric generator unit will be developed by combing with control circuits and converts, which is used to light the LED lamps. The temperature difference which is available in the kitchens, especially the exhaust pipes/chimneys of wooden fire stoves, where more heat is dissipated into the atmosphere, can be utilized for electrical power generation. Hence, the temperature rise of surroundings atmosphere can be reduced.

Keywords: thermo electric generator, LED, converts, temperature

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Authors: Himanshu Payal, Sachin Maheshwari, Pushpendra S. Bharti

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Electrical discharge machining (EDM), a non-conventional machining process, finds wide applications for shaping difficult-to-cut alloys. Process modeling of EDM is required to exploit the process to the fullest. Process modeling of EDM is a challenging task owing to involvement of so many electrical and non-electrical parameters. This work is an attempt to model the EDM process using artificial neural network (ANN). Experiments were carried out on die-sinking EDM taking Inconel 825 as work material. ANN modeling has been performed using experimental data. The prediction ability of trained network has been verified experimentally. Results indicate that ANN can predict the values of performance measures of EDM satisfactorily.

Keywords: artificial neural network, EDM, metal removal rate, modeling, surface roughness

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Authors: M. Haghnegahdar, G. Naderi, M. H. R. Ghoreishy

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Polypropylene(PP)/Ethylene Propylene Diene Monomer (EPDM) samples (80/20) containing 0, 0.5, 1, 1.5, 2, 2.5, and 3 (expressed in mass fraction) graphene were prepared using melt compounding method to investigate microstructure, mechanical properties, and thermal stability as well as electrical resistance of samples. X-Ray diffraction data confirmed that graphene platelets are well dispersed in PP/EPDM. Mechanical properties such as tensile strength, impact strength and hardness demonstrated increasing trend by graphene loading which exemplifies substantial reinforcing nature of this kind of nano filler and it's good interaction with polymer chains. At the same time it is found that thermo-oxidative degradation of PP/EPDM nanocomposites is noticeably retarded with the increasing of graphene content. Electrical surface resistivity of the nanocomposite was dramatically changed by forming electrical percolation threshold and leads to change electrical behavior from insulator to semiconductor. Furthermore, these results were confirmed by scanning electron microscopy(SEM), dynamic mechanical thermal analysis (DMTA), and transmission electron microscopy (TEM).

Keywords: nanocomposite, graphene, microstructure, mechanical properties

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Authors: Tabti Lahouaria, Kahlouche Salem, Benadda Belkacem, Beldjilali Bilal

Abstract:

The European Geostationary Navigation Overlay Service (EGNOS) provides an augmentation signal to GPS (Global Positioning System) single point positioning. Presently EGNOS provides data correction and integrity information using the GPS L1 (1575.42 MHz) frequency band. The main objective of this system is to provide a better real-time positioning precision than using GPS only. They are expected to be used with single-frequency code observations. EGNOS offers navigation performance for an open service (OS), in terms of precision and availability this performance gradually degrades as moving away from the service area. For accurate system performance, the service will become less and less available as the user moves away from the EGNOS service. The improvement in position solution is investigated using the two collocated dual frequency GPS, where no EGNOS Ranging and Integrity Monitoring Station (RIMS) exists. One of the pseudo-range was kept as GPS stand-alone and the other was corrected by EGNOS to estimate the planimetric and altimetric precision for different dates. It is found that precision in position improved significantly in the second due to EGNOS correction. The performance of EGNOS system in the north of Algeria is also investigated in terms of integrity. The results show that the horizontal protection level (HPL) value is below 18.25 meters (95%) and the vertical protection level (VPL) is below 42.22 meters (95 %). These results represent good integrity information transmitted by EGNOS for APV I service. This service is thus compliant with the aviation requirements for Approaches with Vertical Guidance (APV-I), which is characterised by 40 m HAL (horizontal alarm limit) and 50 m VAL (vertical alarm limit).

Keywords: EGNOS, GPS, positioning, integrity, protection level

Procedia PDF Downloads 225

Authors: Mohamed Achehboune, Mohammed Khenfouch, Issam Boukhoubza, Bakang Mothudi, Izeddine Zorkani, Anouar Jorio

Abstract:

Zinc Oxide (ZnO) nanostructures have been attracting growing interest in recent years; their optical and electrical properties make them useful as attractive and promising materials for optoelectronic applications. In this study, pure and Hafnium doped ZnO nanostructures were synthesized using a green processing method. The structural, optical and electrical properties of samples were investigated structural and optical spectroscopies and electrical measurements. The synthesis and chemical composition of pure and Hafnium doped ZnO were confirmed by SEM observation. The XRD studies of Hafnium doped ZnO demonstrate the formation of wurtzite structure with preferred c-axis orientation. Moreover, the optical and electrical properties of doped material have improved after the doping process. The experimental results obtained for our material show that Hf doped ZnO nanostructures could be a promising material in optoelectronic applications such as photovoltaic cell and light emitting diode devices.

Keywords: green synthesis, hafnium-doped-zinc oxide, nanostructures, optoelectronic

Procedia PDF Downloads 271

Authors: Alouaoui Redha, Ferhat Samira, Bouaziz Mohamed Najib

Abstract:

In this work, we examine the thermal radiation effect on heat and mass transfer in steady laminar boundary layer flow of an incompressible viscous micropolar fluid over a vertical plate, with the presence of a magnetic field. Rosseland approximation is applied to describe the radiative heat flux in the energy equation. The resulting similarity equations are solved numerically. Many results are obtained and representative set is displayed graphically to illustrate the influence of the various parameters on different profiles. The conclusion is drawn that the flow field, temperature, concentration and microrotation as well as the skin friction coefficient and the both local Nusselt and local Sherwood numbers are significantly influenced by Magnetic parameter, material parameter and thermal radiation parameter.

Keywords: MHD, micropolar fluid, thermal radiation, heat and mass transfer, boundary layer

Procedia PDF Downloads 453

Authors: Kayode A. Olaniyi, Tola. M. Osifeko, Adeola A. Ogunleye

Abstract:

Text line segmentation is an important step in document image processing. It represents a labeling process that assigns the same label using distance metric probability to spatially aligned units. Text line detection techniques have successfully been implemented mainly in printed documents. However, processing of the handwritten texts especially unconstrained documents has remained a key problem. This is because the unconstrained hand-written text lines are often not uniformly skewed. The spaces between text lines may not be obvious, complicated by the nature of handwriting and, overlapping ascenders and/or descenders of some characters. Hence, text lines detection and segmentation represents a leading challenge in handwritten document image processing. Text line detection methods that rely on the traditional global projection profile of the text document cannot efficiently confront with the problem of variable skew angles between different text lines. Hence, the formulation of a horizontal line as a separator is often not efficient. This paper presents a technique to segment a handwritten document into distinct lines of text. The proposed algorithm starts, by partitioning the initial text image into columns, across its width into chunks of about 5% each. At each vertical strip of 5%, the histogram of horizontal runs is projected. We have worked with the assumption that text appearing in a single strip is almost parallel to each other. The algorithm developed provides a sliding window through the first vertical strip on the left side of the page. It runs through to identify the new minimum corresponding to a valley in the projection profile. Each valley would represent the starting point of the orientation line and the ending point is the minimum point on the projection profile of the next vertical strip. The derived text-lines traverse around any obstructing handwritten vertical strips of connected component by associating it to either the line above or below. A decision of associating such connected component is made by the probability obtained from a distance metric decision. The technique outperforms the global projection profile for text line segmentation and it is robust to handle skewed documents and those with lines running into each other.

Keywords: connected-component, projection-profile, segmentation, text-line

Procedia PDF Downloads 124

Authors: U. Chattaraj, D. Meena

Abstract:

Growth of traffic brings various negative effects, such as road accidents. To avoid such problems, a model is developed for the purpose of highway safety. In such areas, fuzzy logic is the most well-known simulation in the larger field. A model is accomplished for hilly and steep terrain based on Fuzzy Inference System (FIS), for which output is super elevation and input data is horizontal radius, vertical gradient, accident rate (AR). This result shows that the system can be efficaciously applied as for highway safety tool distinguishing hazards components correlated to the characteristics of the highway and has a great influence to the making of decision for accident precaution in transportation models. From this model, a positive relationship between geometric elements, accident rate, and super elevation is also identified.

Keywords: accident rate, fuzzy inference system, fuzzy logic, gradient, radius, super elevation

Procedia PDF Downloads 218