Search results for: cooling device

Authors: Pratham Baheti, Rohan Sanghi, Aditya Gupta

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In the largely populated city of New Delhi, India, there are a lot of people that travel by two-wheelers. Majority of the people wear helmets while traveling and know how important it is to wear helmets for their safety. Still, the number of deaths because of road accidents involving two-wheelers is significant. We had conducted a survey by traveling within and in the outskirts of Delhi so as to see the variation in data and in the opinion of people towards helmet being a safety device rather than to escape the traffic police. We conducted a survey at traffic junctions and crossings of all the stakeholders and collected feedback on the Helmet scenario in India. According to the survey, the possible reason for these deaths is that the people, being unaware of helmet safety standards (ISI standards for helmets), buy helmets with fake ISI mark from unauthorized helmet sellers for a cheap price. Also, for the people who do not wear a helmet at all or wear a helmet just because it is a law, the reasons that they do not want to wear a helmet is heavyweight, lack of ventilation, inconvenience due to a strap, and hair problems. To address all these problems, we are designing a helmet with reduced weight and also working on the Helmet’s retention system and ventilation. We plan to provide this product at a cheap cost whilst maintaining the ISI standards so that a larger section of the population would be able to afford the helmet.

Keywords: safety, survey, ISI marks, stakeholders, helmet

Procedia PDF Downloads 279

Authors: Jin Hwa Yang, Hwang Bae, Sung Uk Ryu, Byong Guk Jeon, Sung Jae Yi, Hyun Sik Park

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Experimental studies using a large-scale thermal-hydraulic integral test facility, System–integrated Modular Advanced Reactor Integral Test Loop (SMART-ITL), have been carried out to validate the performance of the prototype, SMART. After Fukushima accident, the passive safety systems have been dealt as important designs for retaining of nuclear safety. One of the concerned scenarios for evaluating the passive safety system is a Complete Loss of Coolant Flow (CLOF). The flowrate of coolant in the primary system is maintained by Reactor Coolant Pump (RCP). When the supply of electric power of RCP is shut off, the flowrate of coolant decreases sharply, and the temperature of the coolant increases rapidly. Therefore, the reactor trip signal is activated to prevent the over-heating of the core. In this situation, Passive Residual Heat Removal System (PRHRS) plays a significant role to assure the soundness of the SMART. The PRHRS using a two-phase natural circulation is a passive safety system in the SMART to eliminate the heat of steam generator in the secondary system with heat exchanger submarined in the Emergency Cooling Tank (ECT). As the RCPs continue to coast down, inherent natural circulation in the primary system transfers heat to the secondary system. The transferred heat is removed by PRHRS in the secondary system. In this paper, the progress of the CLOF accident is described with experimental data of transient condition performed by SMART-ITL. Finally, the capability of passive safety system and inherent natural circulation will be evaluated.

Keywords: CLOF, natural circulation, PRHRS, SMART-ITL

Procedia PDF Downloads 437

Authors: Loïc Warscotte, Jehan Boreux

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The scientific literature of changepoint detection is vast. Today, a lot of methods are available to detect abrupt changes or slight drift in a signal, based on CUSUM or EWMA charts, for example. However, these methods rely on strong assumptions, such as the stationarity of the stochastic underlying process, or even the independence and Gaussian distributed noise at each time. Recently, the breakthrough research on locally stationary processes widens the class of studied stochastic processes with almost no assumptions on the signals and the nature of the changepoint. Despite the accurate description of the mathematical aspects, this methodology quickly suffers from impractical time and space complexity concerning the signals with high-rate data collection, if the characteristics of the process are completely unknown. In this paper, we then addressed the problem of making this theory usable to our purpose, which is monitoring a high-speed weigh-in-motion system (HS-WIM) towards direct enforcement without supervision. To this end, we first compute bounded approximations of the initial detection theory. Secondly, these approximating bounds are empirically validated by generating many independent long-run stochastic processes. The abrupt changes and the drift are both tested. Finally, this relaxed methodology is tested on real signals coming from a HS-WIM device in Belgium, collected over several months.

Keywords: changepoint, weigh-in-motion, process, non-parametric

Procedia PDF Downloads 78

Authors: Jinkoo Kim, Minsung Kim

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This study develops a hybrid seismic energy dissipation device composed of a viscoelastic damper and a steel slit damper connected in parallel. A cyclic loading test is conducted on a test specimen to validate the seismic performance of the hybrid damper. Then a moment-framed model structure is designed without seismic load so that it is retrofitted with the hybrid dampers. The model structure is transformed into an equivalent simplified system to find out optimum story-wise damper distribution pattern using genetic algorithm. The effectiveness of the hybrid damper is investigated by fragility analysis and the life cycle cost evaluation of the structure with and without the dampers. The analysis results show that the model structure has reduced probability of reaching damage states, especially the complete damage state, after seismic retrofit. The expected damage cost and consequently the life cycle cost of the retrofitted structure turn out to be significantly small compared with those of the original structure. Acknowledgement: This research was supported by the Ministry of Trade, Industry and Energy (MOTIE) and Korea Institute for Advancement of Technology (KIAT) through the International Cooperative R & D program (N043100016).

Keywords: seismic retrofit, slit dampers, friction dampers, hybrid dampers

Procedia PDF Downloads 282

Authors: Akinwale S. O., Koya O. A.

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The need to provide ecologically-friendly and effective lawn mowing solution is crucial for the well-being of humans. This study involved the modification of a human-powered lawn mower designed to cut tall grasses in residential areas. This study designed and fabricated a reel-type mower blade system and a pedal-powered test rig for the blade system. It also evaluated the performance of the machine. The machine was tested on some overgrown grass plots at College of Education Staff School Ilesa. Parameters such as theoretical field capacity, field efficiency and effective field capacity were determined from the data gathered. The quality of cut achieved by the unit was also documented. Test results showed that the fabricated cutting system produced a theoretical field capacity of 0.11 ha/h and an effective field capacity of 0.08ha/h. Moreover, the unit’s cutting system showed a substantial improvement over existing reel mower designs in its ability to cut on both the forward and reverse phases of its motion. This study established that the blade system described herein has the capacity to cut tall grasses. Hence, this device can therefore eliminate the need for powered mowers entirely on small residential lawns.

Keywords: effective field capacity, field efficiency, theoretical field capacity, quality of cut

Procedia PDF Downloads 147

Authors: G. Yoga Sairam Teja, K. Harsha Vardhan, A. Vinay Kumar, K. Nithish Kumar, Ch. Shanthi Priyag

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The emergence of the Internet of Things (IoT) has facilitated better device control and monitoring in the modern world. The constant monitoring of a patient would be drastically altered by the usage of IoT in healthcare. As we've seen in the case of the COVID-19 pandemic, it's important to keep oneself untouched while continuously checking on the patient's heart rate and temperature. Additionally, patients with paralysis should be closely watched, especially if they are elderly and in need of special care. Our "IoT BASED PATIENT HEALTH MONITORING SYSTEM" project uses IoT to track patient health conditions in an effort to address these issues. In this project, the main board is an 8051 microcontroller that connects a number of sensors, including a heart rate sensor, a temperature sensor (LM-35), and a saline water measuring circuit. These sensors are connected via an ESP832 (WiFi) module, which enables the sending of recorded data directly to the cloud so that the patient's health status can be regularly monitored. An LCD is used to monitor the data in offline mode, and a buzzer will sound if any variation from the regular readings occurs. The data in the cloud may be viewed as a graph, making it simple for a user to spot any unusual conditions.

Keywords: IoT, ESP8266, 8051 microcontrollers, sensors

Procedia PDF Downloads 87

Authors: Dona Primasari

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This study examines the antecedent variables of Government Financial Acccounting System (SAKD) implementation and its consequence. The antecedent variables are: decentralization of decision making, adaptation, and the manager support. The consequences are satisfaction and performance officer. This research represents the empirical test which used convenience sampling technics in data collection. The data were collected from 167 officers of local government in the Regional Coordinating Agency for Development of Cross County/City Region III Central Java Province. Data analysis used Structural Equation Model (SEM) with the AMOS 18.0 program. The result of hypothesis examination indicates that six raised hypothesis are accepted and two hypothesis are rejected.

Keywords: decentralization of decision making, adaptation officer, manager support, implementation of Government Accounting Financial System (SAKD), satisfaction and performance officer

Procedia PDF Downloads 389

Authors: Arunas Stirke, Neringa Bakute, Gatis Mozolevskis

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A technology of microfluidics is an emerging tool in the field of biology, medicine and chemistry. Microfluidic device is also known as ‘lab-on-a-chip’ technology [1]. In moving from macro- to microscale, there is unprecedented control over spatial and temporal gradients and patterns that cannot be captured in conventional Petri dishes and well plates [2]. However, there is not a single standard microfluidic chip designated for all purposes – every different field of studies needs a specific microchip with certain geometries, inlet/outlet, channel depth and other parameters to precisely regulate the required function. Since our group is studying an effect of pulsed electric field (PEF) to the cells, we have manufactured a microfluidic chip designated for high-throughput electroporation of cells. In our microchip, a cell culture chamber is divided into two parallel channels by a membrane, meanwhile electrodes for electroporation are attached to the wall of the channels. Both microchannels have their own inlet and outlet, enabling injection of transfection material separately. Our perspective is to perform electroporation of mammalian cells in two different ways: (1) plasmid and cells are injected in the same microchannel and (2) injected into separate microchannels. Moreover, oxygen and pH sensors are integrated on order to analyse cell viability parameters after PEF treatment.

Keywords: microfluidics, chip, fabrication, electroporation

Procedia PDF Downloads 83

Authors: Elham Ahmadi

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This study is conducted with the aim of investigating the effect of moderate physical activity (60% of maximal heart rate-MHR) on blood pressure in an elderly female with hypertension. Hypertension is considered a modifiable risk factor for cardiovascular disease through physical activity. The purpose and significance of this study were to investigate the role of exercise as an alternative therapy since some patients exhibit sensitivity/intolerance to some drugs. Initially, 65 hypertensive females (average age = 49.7 years) (systolic blood pressure, SBP >140 mmHg and/or diastolic blood pressure, DBP>85 mmHg) and 25 hypertensive females as a control group (average age = 50.3 years and systolic blood pressure, SBP >140 mmHg and/or diastolic blood pressure, DBP>85 mmHg) were selected. The subjects were divided based on their age, duration of disease, physical activity, and drug consumption. Then, blood pressure and heart rate (HR) were measured in all of the patients using a sphygmomanometer (pre-test). The exercise sessions consisted of warm-up, aerobic activity, and cooling down (total duration of 20 minutes for the first session up to 55 minutes in the last session). At the end of the 12th session (mid-test) and final session (24th session), blood pressure was measured for the last time (post-test). The control group was without any exercise during the study. The results were analyzed using a t-test. Our results indicated that moderate physical activity was effective in lowering blood pressure by 6.4/5.6–mm Hg for SBP and 2.4/4.3mm Hg for DBP in hypertensive patients, irrespective of age, duration of disease, and drug consumption ( P<.005). The control group indicates no changes in BP. Physical activity programs with moderate intensity (approximately at 60% MHR), three days per week, can be used not only as a preventive measure for diastolic hypertension (DBP>90 mmHg high blood pressure) but also as an alternative to drug therapy in the treatment of hypertension, as well.

Keywords: endurance exercise, elderly female, hypertension, physical activity

Procedia PDF Downloads 97

Authors: Osamede Asowata

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Optimized gain in respect to output power of stand-alone photovoltaic (PV) systems is one of the major focus of PV in recent times. This is evident in its low carbon emission and efficiency. Power failure or outage from commercial providers, in general, does not promote development to public and private sector; these basically limit the development of industries. The need for a well-structured PV system is of importance for an efficient and cost effective monitoring system. The purpose of this paper is to validate the maximum power point of an off-grid PV system taking into consideration the most effective tilt and orientation angles for PV's in the southern hemisphere. This paper is based on analyzing the system using a solar charger with maximum power point tracking (MPPT) from a pulse width modulation (PWM) perspective. The power conditioning device chosen is a solar charger with MPPT. The practical setup consists of a PV panel that is set to an orientation angle of 0°N, with a corresponding tilt angle of 36°, 26°, and 16°. Preliminary results include regression analysis (normal probability plot) showing the maximum power point in the system as well the best tilt angle for maximum power point tracking.

Keywords: poly-crystalline PV panels, solar chargers, tilt and orientation angles, maximum power point tracking, MPPT, Pulse Width Modulation (PWM).

Procedia PDF Downloads 176

Authors: Nadezda Kobzeva

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Under the current trend of globalization, economic and technological dynamics information and the means by which it is delivered and renewed becomes out-of-date rapidly. Thus, educational systems as well as higher education are being seriously tested. New strategies’ developing that is supported by Information and Communication Technology is urgently required. The essential educators’ mission is to meet the demands of the future by preparing our young learners with proper knowledge, skills and innovation capabilities necessary to advance our competitiveness globally. In response to the modern society and future demands, the oldest Siberian Tomsk Polytechnic University has wisely proposed several initiatives to promote the integration of Information and Communication Technology (ICT) in education, and increase the competitiveness of graduates by emphasizing inquiry-based learning, higher order thinking and problem solving. This paper gives a brief overview of how Web Quest as ICT device is being used for language teaching and describes its use advantages for teaching English as a Foreign Language (EFL), in particular business writing skills. This study proposes to use Web Quest to promote higher order thinking and ICT integration in the process of engineers training in Tomsk Polytechnic University, Russia.

Keywords: web quest, web quest in pedagogy, resume (CVs) and cover letter writing skills, ICT integration

Procedia PDF Downloads 379

Authors: J. O. Bodunrin, S. J. Moloi

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This study reports on the x-ray crystallography (XRD) structure of cadmium-implanted p-type silicon, the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of unimplanted and cadmium-implanted silicon-based diodes. Cadmium was implanted at the energy of 160 KeV to the fluence of 10¹⁵ ion/cm². The results obtained indicate that the diodes were well fabricated, and the introduction of cadmium results in a change in behavior of the diodes from normal exponential to ohmic I-V behavior. The C-V measurements, on the other hand, show that the measured capacitance increased after cadmium doping due to the injected charge carriers. The doping density of the p-Si material and the device's Schottky barrier height was extracted, and the doping density of the undoped p-Si material increased after cadmium doping while the Schottky barrier height reduced. In general, the results obtained here are similar to those obtained on the diodes fabricated on radiation-hard material, indicating that cadmium is a promising metal dopant to improve the radiation hardness of silicon. Thus, this study would assist in adding possible options to improve the radiation hardness of silicon to be used in high energy physics experiments.

Keywords: cadmium, capacitance-voltage, current-voltage, high energy physics experiment, x-ray crystallography, XRD

Procedia PDF Downloads 132

Authors: Emre Akyürek, Anthony Huynh, Tatiana Kalganova

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The Ambidextrous Robot Hand is a robotic device with the purpose to mimic either the gestures of a right or a left hand. The symmetrical behavior of its fingers allows them to bend in one way or another keeping a compliant and anthropomorphic shape. However, in addition to gestures they can reproduce on both sides, an asymmetrical mechanical design with a three tendons routing has been engineered to reduce the number of actuators. As a consequence, control algorithms must be adapted to drive efficiently the ambidextrous fingers from one position to another and to include grasping features. These movements are controlled by pneumatic muscles, which are nonlinear actuators. As their elasticity constantly varies when they are under actuation, the length of pneumatic muscles and the force they provide may differ for a same value of pressurized air. The control algorithms introduced in this paper take both the fingers asymmetrical design and the pneumatic muscles nonlinearity into account to permit an accurate control of the Ambidextrous Robot Hand. The finger motion is achieved by combining a classic PID controller with a phase plane switching control that turns the gain constants into dynamic values. The grasping ability is made possible because of a sliding mode control that makes the fingers adapt to the shape of an object before strengthening their positions.

Keywords: ambidextrous hand, intelligent algorithms, nonlinear actuators, pneumatic muscles, robotics, sliding control

Procedia PDF Downloads 296

Authors: Ersilio Tushaj

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The efficient solution that satisfies the optimal condition is an important issue in the structural engineering design problem. The new codes of structural design consist in design methodology that looks after the exploitation of the total resources of the construction material. In recent years some non-deterministic or meta-heuristic structural optimization algorithms have been developed widely in the research community. These methods search the optimum condition starting from the simulation of a natural phenomenon, such as survival of the fittest, the immune system, swarm intelligence or the cooling process of molten metal through annealing. Among these techniques the most known are: the genetic algorithms, simulated annealing, evolution strategies, particle swarm optimization, tabu search, ant colony optimization, harmony search and big bang crunch optimization. In this study, five of these algorithms are applied for the optimum weight design of a steel truss structure with variable geometry but fixed topology. The design process selects optimum distances and size sections from a set of commercial steel profiles. In the formulation of the design problem are considered deflection limitations, buckling and allowable stress constraints. The approach is repeated starting from different initial populations. The design problem topology is taken from an existing steel structure. The optimization process helps the engineer to achieve good final solutions, avoiding the repetitive evaluation of alternative designs in a time consuming process. The algorithms used for the application, the results of the optimal solutions, the number of iterations and the minimal weight designs, will be reported in the paper. Based on these results, it would be estimated, the amount of the steel that could be saved by applying structural analysis combined with non-deterministic optimization methods.

Keywords: structural optimization, non-deterministic methods, truss structures, steel truss

Procedia PDF Downloads 230

Authors: Piotr Żabicki, Paweł Skutta

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The project of a glider with an electric motor charged by solar power is an step toward the future of Polish gliding. Due to the popularity of the SZD-50-3 glider and its type of usage, the project was developed based on this model. By placing an auxiliary engine in the glider, the pilot is guaranteed a safe return to the airport. Since it is a training glider, and routes are mainly flown by student pilots and instructors, the guarantee of returning to the airport allows flights in more challenging thermal conditions, which contributes to better pilot training. In case of worsening weather, the pilot has a reliable return option, which prevents time loss due to field landings and saves money by avoiding delays in training. The glider uses the NOVA 15 LW engine, a solar installation, and technical modifications to reduce the glider's weight. This includes the Misztal spar solution, previously used in the PZL 19 aircraft. Additionally, the use of lighter coverings and materials that handle loads from pulling, straining, and sharing improves the aerodynamic performance of the glider, enhancing its overall efficiency. Every component added to the glider's construction (battery, engine, etc.) has been placed to avoid shifting loads along the axis, thus preventing unintended spins and flat spins. Safety concerns were also addressed. In the event of a battery or engine fire, the pilot's cabin is designed as a detachable part of the structure and is made of composites covered with non-flammable resin. The batteries are also enclosed in separate boxes located in the former "luggage" compartment. Access to the installation connecting the engine, panel, and battery is convenient due to the detachable cabin from the structure and the fact that the entire installation runs under the structure. The batteries also have easy access due to the current closed hatch. Cooling for the battery is provided this way.

Keywords: engineering, girder, glider, solar, spar

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Authors: Karthiyayini Nagarajan, P. V. Ramakrishna

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Radar Imaging techniques provides extensive applications in the field of remote sensing, majorly Synthetic Aperture Radar (SAR) that provide high resolution target images. This paper work puts forward the effective and realizable signal generation and processing for SAR images. The major units in the system include camera, signal generation unit, signal processing unit and display screen. The real radio channel is replaced by its mathematical model based on optical image to calculate a reflected signal model in real time. Signal generation realizes the algorithm and forms the radar reflection model. Signal processing unit provides range and azimuth resolution through matched filtering and spectrum analysis procedure to form radar image on the display screen. The restored image has the same quality as that of the optical image. This SAR imaging system has been designed and implemented using MATLAB and Quartus II tools on Stratix III device as a System (Lab Bench) that works in real time to study/investigate on radar imaging rudiments and signal processing scheme for educational and research purposes.

Keywords: synthetic aperture radar, radio reflection model, lab bench, imaging engineering

Procedia PDF Downloads 497

Authors: Mattahias Maj, Fabio Tatzgern, Karl Adam, Damir Kahrimanovic, Markus Varga

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Torpedo ladles are necessary transport carriages in steel production to move the molten crude iron from the blast furnace to the steel refining plant. This requires the ladles to be high temperature resistant and insulate well to preserve the temperature and hold the risk of solidification at bay. Therefore, the involved refractories lining the inside of the torpedo ladles are chosen mostly according to their thermal properties, although wear of the materials by the liquid iron is also of major importance. In this work, we combined investigations of the thermal behaviour with wear studies of the lining over the whole lifetime of a torpedo ladle. Additional numerical simulations enabled a detailed model of the mechanical loads and temperature propagation at the various stations (heating, filling, emptying, cooling). The core of the investigation were detailed 3D measurements of the ladle’s cavity and thereby quantitative information of the wear progress at different time intervals during the lifetime of the ladles. The measurements allowed for a separation of different wear zones according to severity, namely the “splash zone” where the melt directly hits the ladle, the “melt zone” where during transport always liquid melt is present, and the “slag zone”, where the slag floats on the melt causing the most severe wear loss. Numerical simulations of the filling process were taken to calculate stress levels and temperature gradients, which led to the different onset of wear on those zones. Thermal imaging and punctual temperature measurements allowed for a study of the thermal consequences entailed by the wear onset. Additional “classical” damage analysis of the worn refractories complete the investigation. Thereby the wear mechanisms leading to the substantial wear loss were disclosed.

Keywords: high temperature, tribology, liquid-solid interaction, refractories, thermography

Procedia PDF Downloads 226

Authors: Mehmet Savsar

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Complex Life Support Systems (LSS) are used in all large commercial and public aquariums in order to keep the fish alive. Reliabilities of individual equipment, as well as the complete system, are extremely important and critical since the life and safety of important fish depend on these life support systems. Failure of some critical device or equipment, which do not have redundancy, results in negative consequences and affects life support as a whole. In this paper, we have considered a life support system in a large public aquarium in Kuwait Scientific Center and presented a procedure and analysis to show how the reliability of such systems can be estimated by using appropriate tools and collected data. We have also proposed possible improvements for systems reliability. In particular, addition of parallel components and spare parts are considered and the numbers of spare parts needed for each component to achieve a required reliability during specified lead time are calculated. The results show that significant improvements in system reliability can be achieved by operating some LSS components in parallel and having certain numbers of spares available in the spare parts inventories. The procedures and the results presented in this paper are expected to be useful for aquarium engineers and maintenance managers dealing with LSS.

Keywords: life support systems, aquariums, reliability, failures, availability, spare parts

Procedia PDF Downloads 280

Authors: T. Sikram, M. Ichinose, R. Sasaki

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In the tropics, indoor thermal environment is usually provided by a cooling mode to maintain comfort all year. Indoor thermal environment performance is sometimes different from the standard or from the first design process because of operation, maintenance, and utilization. The field study of thermal environment in the green building is still limited in this region, while the green building continues to increase. This study aims to clarify thermal performance and subjective perception in the green building by testing the temperature set-points. A Thai green office was investigated twice in October 2018 and in May 2019. Indoor environment variables (temperature, relative humidity, and wind velocity) were collected continuously. The temperature set-point was normally set as 23 °C, and it was changed into 24 °C and 25 °C. The study found that this gap of temperature set-point produced average room temperature from 22.7 to 24.6 °C and average relative humidity from 55% to 62%. Thermal environments slight shifted out of the ASHRAE comfort zone when the set-point was increased. Based on the thermal sensation vote, the feeling-colder vote decreased by 30% and 18% when changing +1 °C and +2 °C, respectively. Predicted mean vote (PMV) shows that most of the calculated median values were negative. The values went close to the optimal neutral value (0) when the set-point was set at 25 °C. The neutral temperature was slightly decreased when changing warmer temperature set-points. Building-related symptom reports were found in this study that the number of votes reduced continuously when the temperature was warmer. The symptoms that occurred by a cooler condition had the number of votes more than ones that occurred by a warmer condition. In sum, for this green office, there is a possibility to adjust a higher temperature set-point to +1 °C (24 °C) in terms of reducing cold sensitivity, discomfort, and symptoms. All results could support the policy of changing a warmer temperature of this office to become “a better green building”.

Keywords: thermal environment, green office, temperature set-point, comfort

Procedia PDF Downloads 118

Authors: Ashish Soni, Suman Kalyan Pal

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Transition metal dichalcogenides (TMDCs) are an emerging paradigm for the generation of advanced materials which are capable of utilizing in future device applications. In recent years TMDCs have attracted researchers for their unique band structure in monolayers. Large-area monolayers could become the most appropriate candidate for flexible and thin optoelectronic devices. For this purpose, it is crucial to understand the generation and transport of charge carriers in low dimensions. A deep understanding of photo-generated hot charges and trapped charges is essential to improve the performance of optoelectronic devices. Carrier trapping by the defect states that are introduced during the growth process of the monolayer could influence the dynamical behaviour of charge carriers. Herein, we investigated some aspects of the ultrafast evolution of the initially generated hot carriers and trapped charges in large-area monolayer WS₂ by measuring transient absorption at energies above and below the band gap energy. Our excitation density and energy-dependent measurements reveal the trapping of the initially generated charge carrier. Our results could be beneficial for the development of TMDC-based optoelectronic devices.

Keywords: transient absorption, optoelectronics, 2D materials, TMDCs, exciton

Procedia PDF Downloads 68

Authors: Karthiyayini Nagarajan, P. V. RamaKrishna

Abstract:

Radar Imaging techniques provides extensive applications in the field of remote sensing, majorly Synthetic Aperture Radar(SAR) that provide high resolution target images. This paper work puts forward the effective and realizable signal generation and processing for SAR images. The major units in the system include camera, signal generation unit, signal processing unit and display screen. The real radio channel is replaced by its mathematical model based on optical image to calculate a reflected signal model in real time. Signal generation realizes the algorithm and forms the radar reflection model. Signal processing unit provides range and azimuth resolution through matched filtering and spectrum analysis procedure to form radar image on the display screen. The restored image has the same quality as that of the optical image. This SAR imaging system has been designed and implemented using MATLAB and Quartus II tools on Stratix III device as a System(lab bench) that works in real time to study/investigate on radar imaging rudiments and signal processing scheme for educational and research purposes.

Keywords: synthetic aperture radar, radio reflection model, lab bench

Procedia PDF Downloads 468

Authors: Lochan Basyal

Abstract:

Global Automation is an emerging technology of today’s era and is based on Internet of Things (IoT). Global automation deals with the controlling of electrical appliances throughout the world. The fabrication of this system has been carried out with interfacing an electrical control system module to Raspberry Pi. An electrical control system module includes a relay driver mechanism through which appliances are controlled automatically in respective condition. In this research project, one email ID has been assigned to Raspberry Pi, and the users from different location having different email ID can mail to Raspberry Pi on assigned email address “[email protected]” with subject heading “Device Control” with predefined command on compose email line. Also, a notification regarding current working condition of this system has been updated on respective user email ID. This approach is an innovative way of implementing smart automation system through which a user can control their electrical appliances like light, fan, television, refrigerator, etc. in their home with the use of email facility. The development of this project helps to enhance the concept of smart home application as well as industrial automation.

Keywords: control circuit, e-mail, global automation, internet of things, IOT, Raspberry Pi

Procedia PDF Downloads 167

Authors: Aniket Ganvir, Ritarani Sahu, Suchismita Chinara

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The rapid digitization of various aspects of life is leading to the creation of smart IoT ecosystems, where interconnected devices generate significant amounts of valuable data. However, these IoT devices face constraints such as limited computational resources and bandwidth. Cloud computing emerges as a solution by offering ample resources for offloading tasks efficiently despite introducing latency issues, especially for time-sensitive applications like fog computing. Fog computing (FC) addresses latency concerns by bringing computation and storage closer to the network edge, minimizing data travel distance, and enhancing efficiency. Offloading tasks to fog nodes or the cloud can conserve energy and extend IoT device lifespan. The offloading process is intricate, with tasks categorized as full or partial, and its optimization presents an NP-hard problem. Traditional greedy search methods struggle to address the complexity of task offloading efficiently. To overcome this, the efficient crow search algorithm (ECSA) has been proposed as a meta-heuristic optimization algorithm. ECSA aims to effectively optimize computation offloading, providing solutions to this challenging problem.

Keywords: IoT, fog computing, task offloading, efficient crow search algorithm

Procedia PDF Downloads 58

Authors: Feng Ju Chuang, Yu Wen Wang, Tai Jung Hsieh, Shyh Ming Kuo

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Polylactic acid is a synthetic polymer with good biocompatibility and degradability, is widely used in clinical applications. In this study, we utilized Polylactic acid particles as stimulants for macrophages and the collagen synthesis of co-cultured fibroblasts was evaluated. The results indicated that Polylactic acid particles were nontoxic to cells from 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. No obvious inflammation effect was observed (under the PLLA concentration of 1 mg/mL) after 24-h co-culture of Raw264.7 and NIH3T3 cells (from TNF-α assay). The addition of PLLA particles to the Raw264.7 and NIH3T3 co-cultures increased the synthesis of collagen, the highest collagen synthesis from the fibroblast was the 0.2 mg/mL (approximately 60% increased as compared with without addition Polylactic acid particles). Moreover, a co-axial atomization delivery device was used to percutaneously introduce Polylactic acid particles into the dermis layer and stimulating macrophages to secrete growth factors promoting fibroblasts to produce collagen. The preliminary results demonstrated the synthesis of collagen was increased mildly after the introduction of Polylactic acid particles for 28-d post implantation. The Polylactic acid particles could be successfully introduced into the dermis layer from H&E staining examination, however, the optimum concentration of Polylactic acid particles and the time-period for collagen synthesis still need to be evaluated.

Keywords: collagen synthesis, macrophage, NIH3T3 cells, polylactic acid particles

Procedia PDF Downloads 113

Authors: Ghasem Sharifi, Hamed Shahmohamadi Ousaloo, Milad Azimi, Mehran Mirshams

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The ever-increasing use of satellites demands a search for increasingly accurate and reliable pointing systems. Reaction wheels are rotating devices used commonly for the attitude control of the spacecraft since provide a wide range of torque magnitude and high reliability. The numerical modeling of this device can significantly enhance the accuracy of the satellite control in space. Modeling the wheel rotation in the presence of the various frictions is one of the critical parts of this approach. This paper presents a Dynamic Model Control of a Reaction Wheel (DMCR) in the current control mode. In current-mode, the required current is delivered to the coils in order to achieve the desired torque. During this research, all the friction parameters as viscous and coulomb, motor coefficient, resistance and voltage constant are identified. In order to model identification of a reaction wheel, numerous varying current commands apply on the particular wheel to verify the estimated model. All the parameters of DMCR are identified by classical Levenberg-Marquardt (CLM) optimization method. The experimental results demonstrate that the developed model has an appropriate precise and can be used in the satellite control simulation.

Keywords: experimental modeling, friction parameters, model identification, reaction wheel

Procedia PDF Downloads 233

Authors: M. Orefice, V. Di Vito

Abstract:

This paper provides a description of a Collision Avoidance algorithm that has been developed starting from the mathematical modeling of the flight of insects, in terms of spirals and conchospirals geometric paths. It is able to calculate a proper avoidance manoeuver aimed to prevent the infringement of a predefined distance threshold between ownship and the considered intruder, while minimizing the ownship trajectory deviation from the original path and in compliance with the aircraft performance limitations and dynamic constraints. The algorithm is designed in order to be suitable for real-time applications, so that it can be considered for the implementation in the most recent airborne automatic collision avoidance systems using the traffic data received through an ADS-B IN device. The presented approach is able to take into account the rules-of-the-air, due to the possibility to select, through specifically designed decision making logic based on the consideration of the encounter geometry, the direction of the calculated collision avoidance manoeuver that allows complying with the rules-of-the-air, as for instance the fundamental right of way rule. In the paper, the proposed collision avoidance algorithm is presented and its preliminary design and software implementation is described. The applicability of this method has been proved through preliminary simulation tests performed in a 2D environment considering single intruder encounter geometries, as reported and discussed in the paper.

Keywords: ADS-B Based Application, Collision Avoidance, RPAS, Spiral Geometry.

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Authors: Safoin Aktaou, Aya Al Masri, Kamel Guerchouche, Malorie Martin, Fouad Maaloul

Abstract:

Introduction: In the ‘Magnetic Resonance Imaging (MRI)’ department, all workers involved in preparing the patient, setting it up, tunnel cleaning, etc. are likely to be exposed to ‘ElectroMagnetic fields (EMF)’ emitted by the MRI device. Exposure to EMF can cause adverse radio-biological effects to workers. The purpose of this study is to propose an organizational process to manage and control EMF risks. Materials and methods: The study was conducted at seven MRI departments using machines with 1.5 and 3 Tesla magnetic fields. We assessed the exposure of each one by measuring the two electromagnetic fields (static and dynamic) at different distances from the MRI machine both inside and around the examination room. Measurement values were compared with British and American references (those of the UK's ‘Medicines and Healthcare Regulatory Agency (MHRA)’ and the ‘American Radiology Society (ACR)’). Results: Following the results of EMF measurements and their comparison with the recommendations of learned societies, a zoning system that adapts to needs of different MRI services across the country has been proposed. In effect, three risk areas have been identified within the MRI services. This has led to the development of a good practice guide related to the magnetic protection of MRI workers. Conclusion: The guide established by our study is a standard that allows MRI workers to protect themselves against the risk of electromagnetic fields.

Keywords: comparison with international references, measurement of electromagnetic fields, magnetic protection of workers, magnetic resonance imaging

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Authors: Jaroslaw Mizera, Pawel Wisniewski, Ryszard Sitek

Abstract:

Selective Laser Melting (SLM) is an advanced additive manufacturing technique used for producing parts made of wide range of materials such as: austenitic steel, titanium, nickel etc. In the our experiment we produced a Ti-AlN composite from a mixture of titanium and aluminum nitride respectively 70% at. and 30% at. using SLM technique. In order to define the size of powder particles, laser diffraction tests were performed on HORIBA LA-950 device. The microstructure and chemical composition of the composite was examined by Scanning Electron Microscopy (SEM). The chemical composition in micro areas of the obtained samples was determined by of EDS. The phase composition was analyzed by X-ray phase analysis (XRD). Microhardness Vickers tests were performed using Zwick/Roell microhardness machine under the load of 0.2kG (HV0.2). Hardness measurements were made along the building (xy) and along the plane of the lateral side of the cuboid (xz). The powder used for manufacturing of the samples had a mean particle size of 41μm. It was homogenous with a spherical shape. The specimens were built chiefly from Ti, TiN and AlN. The dendritic microstructure was porous and fine-grained. Some of the aluminum nitride remained unmelted but no porosity was observed in the interface. The formed material was characterized by high hardness exceeding 700 HV0.2 over the entire cross-section.

Keywords: Selective Laser Melting, Composite, SEM, microhardness

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Authors: Khadidja Rahmani, Nahla Bouaziz

Abstract:

Algeria is known for its rich heritage. It owns an immense historical heritage with a universal reputation. Unfortunately, this wealth is withered because of abundance. This research focuses on the Ksourian model, which constitutes a large portion of this wealth. In fact, the Ksourian model is not just a witness to a great part of history or a vernacular culture, but also it includes a panoply of assets in terms of energetic efficiency. In this context, the purpose of our work is to evaluate the performance of the old techniques which are derived from the Ksourian model , and that using the simulation tools. The proposed method is decomposed in two steps; the first consists of isolate and reintroduce each device into a basic model, then run a simulation series on acquired models. And this in order to test the contribution of each of these dialectal processes. In another scale of development, the second step consists of aggregating all these processes in an aboriginal model, then we restart the simulation, to see what it will give this mosaic on the environmental and energetic plan .The model chosen for this study is one of the ksar units of Knadsa city of Bechar (Algeria). This study does not only show the ingenuity of our ancestors in their know-how, and their adapting power to the aridity of the climate, but also proves that their conceptions subscribe in the current concerns of energy efficiency, and respond to the requirements of sustainable development.

Keywords: dialectal processes, energy efficiency, evaluation, Ksourian model, simulation tools

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Authors: Abdelmessih Malak Sadek Labib

Abstract:

The Stability in harsh environments thanks to excellent electrical, mechanical and thermal properties is what ceramics are all about selected materials for many applications despite advent of new materials such as plastics and composites. However, ceramic materials have disadvantages, including brittleness. Fragility is often attributed to pottery strong covalent and ionic bonds in the ceramic body. There is still much to learn about brittle cracks in a attention to detail, hence the fragility of the ceramic and its catastrophic failure of a frequently studied topic, particularly in charging applications. One of the most commonly used ceramics for load-bearing applications such as veneers is porcelain. Porcelain is a type of traditional pottery. Traditional pottery consists mainly of three basic ingredients: clay, which gives plasticity; silica which maintains the shape and stability of the ceramic body over temperature high temperature; and feldspar affecting glazing. In traditional pottery, the inversion of quartz during cooling the process can create microcracks that act as a stress concentration centers. Consequently, subcritical crack growth is caused due to quartz inversion origins unpredictable catastrophic failure of the work of ceramic bodies when reloading. In the case of porcelain, however, this is what the mullite hypothesis says the strength of porcelain can be significantly increased with felt Interlocking of mullite needles in the ceramic body.in this way realistic assessment of the role of quartz and mullite Porcelain with a strength of is needed to grow stronger and smaller fragile porcelain. Currently,the lack of reports on Young's moduli in the literature leads to erroneous conclusions in this regard mechanical behavior of porcelain. Therefore, the current project uses the Young's modulus approach for the investigation the role of quartz and mullite on the mechanical strength of various porcelains, in addition to reducing particle size, flexural strength fractographic forces and techniques.

Keywords: materials, technical, ceramics, properties, thermal, stability, advantages

Procedia PDF Downloads 84