Search results for: cyber operation capabilities

Authors: Cam Nguyen

Abstract:

Rapid, accurate, and safe sensing and imaging of physical quantities or structures finds many applications and is of significant interest to society. Sensing and imaging using radio-frequency (RF) techniques, particularly, has gone through significant development and subsequently established itself as a unique territory in the sensing world. RF sensing and imaging has played a critical role in providing us many sensing and imaging abilities beyond our human capabilities, benefiting both civilian and military applications - for example, from sensing abnormal conditions underneath some structures’ surfaces to detection and classification of concealed items, hidden activities, and buried objects. We present the developments of several sensing and imaging systems implementing RF technologies like ultra-wide band (UWB), synthetic-pulse, and interferometry. These systems are fabricated completely using RF integrated circuits. The UWB impulse system operates over multiple pulse durations from 450 to 1170 ps with 5.5-GHz RF bandwidth. It performs well through tests of various samples, demonstrating its usefulness for subsurface sensing. The synthetic-pulse system operating from 0.6 to 5.6 GHz can assess accurately subsurface structures. The synthetic-pulse system operating from 29.72-37.7 GHz demonstrates abilities for various surface and near-surface sensing such as profile mapping, liquid-level monitoring, and anti-personnel mine locating. The interferometric system operating at 35.6 GHz demonstrates its multi-functional capability for measurement of displacements and slow velocities. These RF sensors are attractive and useful for various surface and subsurface sensing applications. This paper was made possible by NPRP grant # 6-241-2-102 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.

Keywords: RF sensors, radars, surface sensing, subsurface sensing

Procedia PDF Downloads 313

Authors: Ehsan Sadie

Abstract:

Despite the experience of heavy losses and damages of recent earthquakes such as 8 km E of Pāhala, Hawaii, 11 km W of Salvaleón de Higüey, Dominican Republic and 49 km SSE of Punta Cana, Dominican Republic earthquakes, the possibility of large earthquakes in most populated areas of any country and the serious need for quality control in the design and implementation of buildings, not enough attention has been paid to the proper construction. Steel structures constitute a significant part of construction in any metropolitan area. This article gives a brief overview of the implementation status of these buildings in urban areas and considers the weaknesses of performance that typically occur due to negligence or insufficient mastery of the building supervisor in the principles of operation of earthquake-resistant buildings, and provide appropriate and possible solutions to improve the construction.

Keywords: bracing member, concentrated load, diaphragm system, earthquake engineering, load-bearing system, shear force, seismic retrofitting, steel building, strip foundation, supervising engineer, vulnerability of building

Procedia PDF Downloads 142

Authors: Emanuela Paranhos Lima, Vitaly Félix Rodríguez Esquerre

Abstract:

In this work, efficient directional coupler composed of dielectric waveguides and metallic film has been analyzed in details by simulations using finite element method (FEM). The structure consists of a step-index fiber with dielectric core, silica cladding, and a metal nanowire parallel to the core. The results show that an efficient conversion of optical dielectric modes to long range plasmonic is possible. Low insertion losses in conjunction with short coupling length and a broadband operation can be achieved under certain conditions. This kind of couplers has potential applications for the design of photonic integrated circuits for signal routing between dielectric/plasmonic waveguides, sensing, lithography, and optical storage systems. A high efficient focusing of light in a very small region can be obtained.

Keywords: directional coupler, finite element method, metallic nanowire, plasmonic, surface plasmon polariton, superfocusing

Procedia PDF Downloads 269

Authors: Yinan Cao, Francine Herrmann

Abstract:

Adversary emulation is a very effective concrete way to evaluate the defense of an information system or network. It is about building an emulator, which depending on the vulnerability of a target system, will allow to detect and execute a set of identified attacks. However, emulating an adversary is very costly in terms of time and resources. Verifying the information of each technique and building up the countermeasures in the middle of the test is also needed to be accomplished manually. In this article, a synthesis of previous MITRE research on the creation of the ATT&CK matrix will be as the knowledge base of the known techniques and a well-designed adversary emulation software CALDERA based on ATT&CK Matrix will be used as our platform. Inspired and guided by the previous study, a plugin in CALDERA called Tinker will be implemented, which is aiming to help the tester to get more information and also the mitigation of each technique used in the previous operation. Furthermore, the optional countermeasures for some techniques are also implemented and preset in Tinker in order to facilitate and fasten the process of the defense improvement of the tested system.

Keywords: automation, adversary emulation, CALDERA, countermeasures, MITRE ATT&CK

Procedia PDF Downloads 201

Authors: Charles Koduru, Parth Patel, M. Hassan Tanveer

Abstract:

In this paper, the communication between a team of robots is used to sanitize an environment with germs is proposed. We introduce capabilities from a team of robots (most likely heterogeneous), a wheeled robot named ROSbot 2.0 that consists of a mounted LiDAR and Kinect sensor, and a modified prototype design of a unicycle-drive Roomba robot called the UV robot. The UV robot consists of ultrasonic sensors to avoid obstacles and is equipped with an ultraviolet light system to disinfect and kill germs, such as bacteria and viruses. In addition, the UV robot is equipped with disinfectant spray to target hidden objects that ultraviolet light is unable to reach. Using the sensors from the ROSbot 2.0, the robot will create a 3-D model of the environment which will be used to factor how the ultraviolet robot will disinfect the environment. Together this proposed system is known as the RME assistive robot device or RME system, which communicates between a navigation robot and a germ disinfecting robot operated by a user. The RME system includes a human-machine interface that allows the user to control certain features of each robot in the RME assistive robot device. This method allows the cleaning process to be done at a more rapid and efficient pace as the UV robot disinfects areas just by moving around in the environment while using the ultraviolet light system to kills germs. The RME system can be used in many applications including, public offices, stores, airports, hospitals, and schools. The RME system will be beneficial even after the COVID-19 pandemic. The Kennesaw State University will continue the research in the field of robotics, engineering, and technology and play its role to serve humanity.

Keywords: multi robot system, assistive robots, COVID-19 pandemic, ultraviolent technology

Procedia PDF Downloads 182

Authors: Ye Ling, Ruan Haihui

Abstract:

Aqueous Zn-ion hybrid supercapacitors (AZHSCs) pertain to a new type of electrochemical energy storage device that has received considerable attention. They integrate the advantages of high-energy Zn-ion batteries and high-power supercapacitors to meet the demand for low-cost, long-term durability, and high safety. Nevertheless, the challenge caused by the finite ion adsorption/desorption capacity of carbon electrodes gravely limits their energy densities. This work describes titanium nitride@nitrogen-doped carbon nanocage (TiN@NCNC) composite cathodes for AZHSCs to achieve a greatly improved energy density, and the composites can be facile synthesized based on the calcination of a mixture of tetrabutyl titanate and zeolitic imidazolate framework-8 in argon atmosphere. The resulting composites are featured by the ultra-fine TiN particles dispersed uniformly on the NCNC surfaces, enhancing the Zn2+ storage capabilities. Using TiN@NCNC cathodes, the AZHSCs can operate stably with a high energy density of 154 Wh kg-¹ at a specific power of 270 W kg-¹ and achieve a remarkable capacity retention of 88.9% after 104 cycles at 5 A g-¹. At an extreme specific power of 8.7 kW kg-1, the AZHSCs can retain an energy density of 97.2 Wh kg-1. With these results, we stress that the TiN@NCNC cathodes render high-performance AZHSCs, and the facile one-pot method can easily be scaled up, which enables AZHSCs a new energy-storage component for managing intermitted renewable energy sources.

Keywords: Zn-ion hybrid supercapacitors, ion absorption/desorption reactions, titanium nitride, zeolitic imidazolate framework-8

Procedia PDF Downloads 42

Authors: J. Martin, A. Dannenberg, G. Detrell, R. Ewald, S. Fasoulas

Abstract:

Microalgae-based photobioreactors (PBR) for Life Support Systems (LSS) are currently being investigated for future space missions such as a crewed base on planets or moons. Biological components may help reducing resupply masses by closing material mass flows with the help of regenerative components. Via photosynthesis, the microalgae use CO₂, water, light and nutrients to provide oxygen and biomass for the astronauts. These capabilities could have synergies with Earth applications that tackle current problems and the developed technologies can be transferred. For example, a current worldwide discussed issue is the increased nitrate and phosphate pollution of ground water from agricultural waste waters. To investigate the potential use of a biological system based on the ability of the microalgae to extract and use nitrate and phosphate for the treatment of polluted ground water from agricultural applications, a scalable test stand is being developed. This test stand investigates the maximization of intake rates of nitrate and quantifies the produced biomass and oxygen. To minimize the required energy, for the uptake of nitrate from artificial waste water (AWW) the Flashing Light Effect (FLE) and the adaption of the illumination spectrum were realized. This paper describes the composition of the AWW, the development of the illumination unit and the possibility of non-invasive process optimization and control via the adaption of the illumination spectrum and illumination cycles. The findings were a doubling of the energy related growth rate by adapting the illumination setting.

Keywords: microalgae, illumination, nitrate uptake, flashing light effect

Procedia PDF Downloads 107

Authors: Fikri Suwaileh

Abstract:

In the reverse osmosis (RO) water treatment plant, operation was suffering from several leaks on the acid injection point spool and downstream spools, due to insufficient injection monitoring and the coating failure leading to pin holes. The paper will go over the background of the leaks in the acid injection point, the process in the RO plant, the material, and coating used in the existing spools, the impact of these repeated leaks, the type of damage mechanism that occurred in the system due to the manner of acid injection and the heat in the spools, which lead to coating failure, leaks and water release. This paper will also look at the analysis, both the short- and long-term recommendations, and the utilization of Teflon internal lining to stop the leaks. Sharing this case study will enhance the knowledge of the importance of taking all factors that will lead to leaks in the acid injection points, along with the importance of utilizing the appropriate coating material lining to enhance the full system.

Keywords: corrosion, coating, raw water, lining

Procedia PDF Downloads 9

Authors: Longondjo Etambakonga Clement

Abstract:

Local municipality responsible for solid waste management (SWM) in many developing countries is facing real challenge. This is even more critical in the country facing political instability. Few decades ago, it has emerged new urban governance including partnerships and involvement of formal and informal actors for an effective and sustainable solid waste management. This paper identifies SWM actors and analyzes their roles to sustainable development in Kinshasa. An attempt has been to examine the challenges facing the actors in managing effectively waste in the city. The study is based on the empirical data gathered in the years 2009 and 2014 in Kinshasa using expert interviews, observation and documentation. The findings indicate that solid waste in the city is poorly managed, activities not coordinated and fragmented, as consequence severe public health and environmental problems. Five group actors are involved in SWM in the city including government, private business, NGOs/CBOs/donors, household, scavengers, in which, scavengers are more visible in collection and recycling activities. The results suggest that recognition of informal collectors and recyclers (scavengers) and strengthening alliances among all SWM stakeholders can lead to greater effective SWM in the city. The key lessons learned include lack of city’s SWM culture over SWM, unwillingness to pay and lack of environmental consciences are the main obstructions to sustainable SWM, therefore there is a need for social capital approach to empower individual and group actors as to create capabilities for an sustainable SWM.

Keywords: challenges, institutions, political instability, scavengers, solid waste management, sustainable development

Procedia PDF Downloads 345

Authors: Mohammed Saif Al-Saidi, John P. T. Mo

Abstract:

Modern engineering assets are complex and very high in value. They are expected to function for years to come, with ability to handle the change in technology and ageing modification. The aging of an engineering asset and continues increase of vendors and contractors numbers forces the asset operation management (or Owner) to design an asset system which can capture these changes. Furthermore, an accurate performance measurement and risk evaluation processes are highly needed. Therefore, this paper explores the nature of the asset management system performance evaluation for an engineering asset based on the System Support Engineering (SSE) principles. The research work explores the asset support system from a range of perspectives, interviewing managers from across a refinery organisation. The factors contributing to complexity of an asset management system are described in context which clusters them into several key areas. It is proposed that SSE framework may then be used as a tool for analysis and management of asset. The paper will conclude with discussion of potential application of the framework and opportunities for future research.

Keywords: asset management, performance, evaluation, modern engineering, System Support Engineering (SSE)

Procedia PDF Downloads 673

Authors: Marlon Gallo, Eduardo Miguel, Laura Oca, Eneko Gonzalez, Unai Iraola

Abstract:

The heat generation of an energy storage system is an essential topic when designing a battery pack and its cooling system. Heat generation estimation is used together with thermal models to predict battery temperature in operation and adapt the design of the battery pack and the cooling system to these thermal needs guaranteeing its safety and correct operation. In the present work, a comparison between the use of a heat flux sensor (HFS) for indirect measurement of heat losses in a cell and the widely used and simplified version of Bernardi’s equation for estimation is presented. First, a Li-ion cell is thermally characterized with an HFS to measure the thermal parameters that are used in a first-order lumped thermal model. These parameters are the equivalent thermal capacity and the thermal equivalent resistance of a single Li-ion cell. Static (when no current is flowing through the cell) and dynamic (making current flow through the cell) tests are conducted in which HFS is used to measure heat between the cell and the ambient, so thermal capacity and resistances respectively can be calculated. An experimental platform records current, voltage, ambient temperature, surface temperature, and HFS output voltage. Second, an equivalent circuit model is built in a Matlab-Simulink environment. This allows the comparison between the generated heat predicted by Bernardi’s equation and the HFS measurements. Data post-processing is required to extrapolate the heat generation from the HFS measurements, as the sensor records the heat released to the ambient and not the one generated within the cell. Finally, the cell temperature evolution is estimated with the lumped thermal model (using both HFS and Bernardi’s equation total heat generation) and compared towards experimental temperature data (measured with a T-type thermocouple). At the end of this work, a critical review of the results obtained and the possible mismatch reasons are reported. The results show that indirectly measuring the heat generation with HFS gives a more precise estimation than Bernardi’s simplified equation. On the one hand, when using Bernardi’s simplified equation, estimated heat generation differs from cell temperature measurements during charges at high current rates. Additionally, for low capacity cells where a small change in capacity has a great influence on the terminal voltage, the estimated heat generation shows high dependency on the State of Charge (SoC) estimation, and therefore open circuit voltage calculation (as it is SoC dependent). On the other hand, with indirect measuring the heat generation with HFS, the resulting error is a maximum of 0.28ºC in the temperature prediction, in contrast with 1.38ºC with Bernardi’s simplified equation. This illustrates the limitations of Bernardi’s simplified equation for applications where precise heat monitoring is required. For higher current rates, Bernardi’s equation estimates more heat generation and consequently, a higher predicted temperature. Bernardi´s equation accounts for no losses after cutting the charging or discharging current. However, HFS measurement shows that after cutting the current the cell continues generating heat for some time, increasing the error of Bernardi´s equation.

Keywords: lithium-ion battery, heat flux sensor, heat generation, thermal characterization

Procedia PDF Downloads 382

Authors: Seif Naoui, Lassaad Latrach, Ali Gharsallah

Abstract:

This paper is specialized to highlight the method of miniaturization and improvement the patch antenna by using the complementary metamaterial. This method is presented by a simple technique is composed a structure of patch antenna integrated in its surface a cell of complementary split ring resonator. This resonator is placed at the middle of the radiating patch in parallel with the transmission line and with a variable angle of orientation. The objective is to find the ultimate angle where the best results are obtained on improving the characteristics of the considered antenna. This motif widespread at the traceability applications by wireless communication for RFID technology at the operation frequency 2.45 GHz. Our contribution is based on studies empirical often presented in this article. All simulation results were made by the CST Microwave Studio.

Keywords: complimentary split ring resonators, computer simulation technology microwave studio, metamaterials patch antennas, microstrip patch antenna, radio frequency identification

Procedia PDF Downloads 435

Authors: Ainagul Yermekova, Liudmila Goncharenko, Ali Baghirzade, Sergey Sybachin

Abstract:

In this article, we address the problem of Kazakhstan's transition to the Latin alphabet. The transition process started in 2017 and is scheduled to be completed in 2025. In connection with these events, the problem of recognizing the characters of the new alphabet is raised. Well-known character recognition programs such as ABBYY FineReader, FormReader, MyScript Stylus did not recognize specific Kazakh letters that were used in Cyrillic. The author tries to give an assessment of the well-known method of character recognition that could be in demand as part of the country's transition to the Latin alphabet. Three methods of character recognition: template, structured, and feature-based, are considered through the algorithms of operation. At the end of the article, a general conclusion is made about the possibility of applying a certain method to a particular recognition process: for example, in the process of population census, recognition of typographic text in Latin, or recognition of photos of car numbers, store signs, etc.

Keywords: text detection, template method, recognition algorithm, structured method, feature method

Procedia PDF Downloads 182

Authors: Neerja Ahlawat

Abstract:

In Indian society, women have always been an active part of the production process. Be it agriculture, dairy, or other home-based industries, Indian women have been competent and enterprising engaged in multiple economic activities. In recent times, women across the country have started establishing business enterprise and managing and working very hard. Despite their skills and capabilities, however, women are faced with varied problems and challenges. Women entrepreneurs in Haryana face a double challenge – a gender bias against women denies them the education and the opportunities available to their male counterparts and the lack of such learning and skills development inhibits any entrepreneurial ambitions. In many parts of the state, women venturing out of the household domain face much opposition and criticism. The present paper highlights the various problems and challenges faced by the women entrepreneurs while running the enterprises in the present competitive world in Haryana. An attempt has been made to investigate women entrepreneurs about the specific issues such as working capital, distribution channel, sales promotion, electricity, human resources and competition with other industries. The present empirical study was carried out in Rohtak city of Haryana using Interview schedule and Case study method. The study revealed the nature of problems women entrepreneurs face while dealing with issues of labour, market, and bureaucracy. The study categorically pointed out the difficulties women are confronted with while keeping a balance between domestic responsibilities and workplace challenges. The study concluded that women entrepreneurs are redefining their identities and priorities in the male dominant society.

Keywords: entrepreneur, gender bias, capital, human resource

Procedia PDF Downloads 183

Authors: Ruben Lopez-Rodriguez

Abstract:

In a microgrid, diverse energy sources (both renewable and non-renewable) are combined with energy storage units to form a localized power system. Microgrids function as independent entities, capable of meeting the energy needs of specific areas or communities. This paper introduces a Model Predictive Control (MPC) approach tailored for grid-connected microgrids, aiming to optimize their operation. The formulation employs Mixed-Integer Programming (MIP) to find optimal trajectories. This entails the fulfillment of continuous and binary constraints, all while accounting for commutations between various operating conditions such as storage unit charge/discharge, import/export from/towards the main grid, as well as asset connection/disconnection. To validate the proposed approach, a microgrid case study is conducted, and the simulation results are compared with those obtained using a rule-based strategy.

Keywords: microgrids, mixed logical dynamical systems, mixed-integer optimization, model predictive control

Procedia PDF Downloads 44

Authors: Klytaimnistra Katsara, George Kenanakis, Eleftherios Alissandrakis, Vassilis M. Papadakis

Abstract:

In recent decades, microplastics (MPs) attracted the interest of the research community as the level of environmental plastic pollution has increased over the years. Through air inhalation and food consumption, MPs enter the human body, creating a series of possible health issues. The majority of MPs enter through the digestive tract; they migrate from the plastic packaging of the foodstuffs. Several plastics, such as Polyethylene (PE), are commonly used as food packaging material due to their preservation and storage capabilities. In this work, the surfaces of three different cured meat products with varied fat compositions were studied (bacon, mortadella, and salami) to determine the migration of MPs from plastic packaging. Micro-Raman spectroscopic measurements were performed in an experimental set lasting 28 days, where the meat samples were stored in vacuum-sealed low-density polyethylene (LDPE) pouches under refrigeration conditions at 4°C. Specific measurement days (0, 3, 9, 12, 15, and 28 days of storage) were chosen to obtain comparative results. Raman micro-spectroscopy was used to monitor the MPs migration, where the Raman spectral profile of LDPE first appeared on day 9 in Bacon, day 15 in Salami, and finally, on day 28 in Mortadella. All the meat samples on day 28 were tainted because a layer of bacterial outgrowth had developed on their surface. In conclusion, MP migration from food packaging to the surface of the cured meat samples was proven. To minimize the consumption of MPs in cured meat products that are stored in plastic packaging, a short period of storage time under refrigeration conditions is advised.

Keywords: cured meat, food packaging, low-density polyethylene, microplastic migration, micro-Raman spectroscopy

Procedia PDF Downloads 69

Authors: Oliver Commichau, Richard Krimm, Bernd-Arno Behrens

Abstract:

A growing demand on the production rate of modern presses leads to higher stroke rates. Commonly used material feeding devices for presses like grippers and roll-feeding systems can only achieve high stroke rates along with high gripper forces, to avoid stick-slip. These forces are limited by the sensibility of the surfaces of the workpieces. Stick-slip leads to scratches on the surface and false positioning of the workpiece. In this paper, a new contactless feeding device is presented, which develops higher feeding force without damaging the surface of the workpiece through gripping forces. It is based on the principle of the linear induction motor. A primary part creates a magnetic field and induces eddy currents in the electrically conductive material. A Lorentz-Force applies to the workpiece in feeding direction as a mutual reaction between the eddy-currents and the magnetic induction. In this study, the FEA model of this approach is shown. The calculation of this model was used to identify the influence of various design parameters on the performance of the feeder and thus showing the promising capabilities and limits of this technology. In order to validate the study, a prototype of the feeding device has been built. An experimental setup was used to measure pulling forces and placement accuracy of the experimental feeder in order to give an outlook of a potential industrial application of this approach.

Keywords: conductive material, contactless feeding, linear induction, Lorentz-Force

Procedia PDF Downloads 176

Authors: Kawai Nobuaki

Abstract:

This paper describes the design and implementation of web system for continuable and viable collaboration. This study proposes the improvement of the system based on a result of a certain practice. As contemporary higher education information environments transform, this study highlights the significance of university identity and college identity that are formed continuously through independent activities of the students. Based on these discussions, the present study proposes a practical media environment design which facilitates the processes of organizational identity formation based on a continuous and cyclical model. Even if users change by this system, the communication system continues operation and cooperation. The activity becomes the archive and produces new activity. Based on the result, this study elaborates a plan with a re-design by a system from the viewpoint of second-order cybernetics. Systems theory is a theoretical foundation for our study.

Keywords: collaborative work, learning management system, second-order cybernetics, systems theory, user generated contents, viable system model

Procedia PDF Downloads 209

Authors: E. A. Krasikov

Abstract:

As the service life of an operating nuclear power plant (NPP) increases, the potential misunderstanding of the degradation of aging components must receive more attention. Integrity assurance analysis contributes to the effective maintenance of adequate plant safety margins. In essence, the reactor pressure vessel (RPV) is the key structural component determining the NPP lifetime. Environmentally induced cracking in the stainless steel corrosion-preventing cladding of RPV’s has been recognized to be one of the technical problems in the maintenance and development of light-water reactors. Extensive cracking leading to failure of the cladding was found after 13000 net hours of operation in JPDR (Japan Power Demonstration Reactor). Some of the cracks have reached the base metal and further penetrated into the RPV in the form of localized corrosion. Failures of reactor internal components in both boiling water reactors and pressurized water reactors have increased after the accumulation of relatively high neutron fluences (5´1020 cm–2, E>0,5MeV). Therefore, in the case of cladding failure, the problem arises of hydrogen (as a corrosion product) embrittlement of irradiated RPV steel because of exposure to the coolant. At present when notable progress in plasma physics has been obtained practical energy utilization from fusion reactors (FR) is determined by the state of material science problems. The last includes not only the routine problems of nuclear engineering but also a number of entirely new problems connected with extreme conditions of materials operation – irradiation environment, hydrogenation, thermocycling, etc. Limiting data suggest that the combined effect of these factors is more severe than any one of them alone. To clarify the possible influence of the in-service synergistic phenomena on the FR structural materials properties we have studied hydrogen-irradiated steel interaction including alternating hydrogenation and heat treatment (annealing). Available information indicates that the life of the first wall could be expanded by means of periodic in-place annealing. The effects of neutron fluence and irradiation temperature on steel/hydrogen interactions (adsorption, desorption, diffusion, mechanical properties at different loading velocities, post-irradiation annealing) were studied. Experiments clearly reveal that the higher the neutron fluence and the lower the irradiation temperature, the more hydrogen-radiation defects occur, with corresponding effects on the steel mechanical properties. Hydrogen accumulation analyses and thermal desorption investigations were performed to prove the evidence of hydrogen trapping at irradiation defects. Extremely high susceptibility to hydrogen embrittlement was observed with specimens which had been irradiated at relatively low temperature. However, the susceptibility decreases with increasing irradiation temperature. To evaluate methods for the RPV’s residual lifetime evaluation and prediction, more work should be done on the irradiated metal–hydrogen interaction in order to monitor more reliably the status of irradiated materials.

Keywords: hydrogen, radiation, stability, structural steel

Procedia PDF Downloads 266

Authors: I Made Ginarsa, Agung Budi Muljono, I Made Ari Nrartha

Abstract:

Transient voltage response appears in power system operation when an additional loading is forced to load bus of power systems. In this research, improvement of transient voltage response is done by using power system stabilizer-static var compensator (PSS-SVC) based on adaptive neuro-fuzzy inference system (ANFIS)-algorithm. The main function of the PSS is to add damping component to damp rotor oscillation through automatic voltage regulator (AVR) and excitation system. Learning process of the ANFIS is done by using off-line method where data learning that is used to train the ANFIS model are obtained by simulating the PSS-SVC conventional. The ANFIS model uses 7 Gaussian membership functions at two inputs and 49 rules at an output. Then, the ANFIS-PSS and ANFIS-SVC models are applied to power systems. Simulation result shows that the response of transient voltage is improved with settling time at the time of 4.25 s.

Keywords: improvement, transient voltage, PSS-SVC, ANFIS, settling time

Procedia PDF Downloads 572

Authors: Munirah Ismail, Joon Hock Yeo

Abstract:

Babies born with Tetralogy of Fallot, a congenital heart defect, are required to undergo reconstruction surgery to create a valved conduit. As the child matures, the partially reconstructed pulmonary conduit increases in diameter, while the size of the reconstructed valve remains the same. As a result, follow up surgery is required to replace the undersized valve. Thus, in this project, we evaluated the in-vitro performance of a bi-leaflet valve design in terms of percentage regurgitation with increasing artery (conduit) diameters. Results revealed percentage regurgitations ranging from 13% to 34% for conduits tested. It was observed that percentage of regurgitation increased exponentially with increasing diameters. While the amount of regurgitation may seem severe, it is deemed acceptable, and this valve could potentially reduce the frequency of re-operation in the lifetime of pediatric patients.

Keywords: pulmonary heart valve, tetralogy of fallot, expanded polytetrafluoroethylene valve, pediatric heart valve replacement

Procedia PDF Downloads 170

Authors: Yi-Ning Chang

Abstract:

With the rapid advancement of technology, it has become crucial for educators to adeptly integrate technology into their teaching and develop a robust Computer-Assisted Language Learning (CALL) competency. Addressing this need, the present study adopted a technology-based Lesson Study approach to assess its impact on the CALL competency and professional capabilities of EFL teachers. Additionally, the study delved into teachers' perceptions of the benefits derived from participating in the creation of technologically integrated lesson plans. The iterative process of technology-based Lesson Study facilitated ample peer discussion, enabling teachers to flexibly design and implement lesson plans that incorporate various technological tools. This 15-week study included 10 in- service teachers from a university of science and technology in the central of Taiwan. The collected data included pre- and post- lesson planning scores, pre- and post- TPACK survey scores, classroom observation forms, designed lesson plans, and reflective essays. The pre- and post- lesson planning and TPACK survey scores were analyzed employing a pair-sampled t test; students’ reflective essays were respectively analyzed applying content analysis. The findings revealed that the teachers’ lesson planning ability and CALL competencies were improved. Teachers perceived a better understanding of integrating technology with teaching subjects, more effective teaching skills, and a deeper understanding of technology. Pedagogical implications and future studies are also discussed.

Keywords: CALL, language learning, lesson study, lesson plan

Procedia PDF Downloads 34

Authors: Priyanka Gupta, Bipin Kumar

Abstract:

Recent developments in smart materials motivate researchers to create novel textile products for innovative and functional applications, which have several potential uses beyond the conventional. This study investigates the memory behavior of shape memory filaments integrated into a knitted textile structure. The research advances the knowledge of how these intelligent materials respond within textile structures. This integration may also open new avenues for developing smart fabrics with unique sensing and actuation capabilities. A shape memory filament and polyester yarn were knitted to produce a shape memory knitted fabric (SMF). Thermo-mechanical tensile test was carried out to quantify the memory behavior of SMF under different conditions. The experimental findings demonstrate excellent shape recovery (100%) and shape fixity up to 88% at different strains (20% and 60%) and temperatures (30 ℃ and 50 ℃). Experimental results reveal that memory filament behaves differently in a fabric structure than in its pristine condition at various temperatures and strains. The cycle test of SMF under different thermo-mechanical conditions indicated complete shape recovery with an increase in shape fixity. So, the utterly recoverable textile structure was achieved after a few initial cycles. These intelligent textiles are beneficial for the development of novel, innovative, and functional fabrics like elegant curtains, pressure garments, compression stockings, etc. In addition to fashion and medical uses, this unique feature may also be leveraged to build textile-based sensors and actuators.

Keywords: knitting, memory filament, shape memory, smart textiles, thermo-mechanical cycle

Procedia PDF Downloads 85

Authors: Leonardo Herrera, Shield B. Lin, Stephen J. Montgomery-Smith, Ziraguen O. Williams

Abstract:

A one-directional dynamic model of a Stewart Platform was developed to assist NASA in analyzing the dynamic response in spacecraft docking operations. A simplified mechanical drawing was created, capturing the physical structure's main features. A simplified schematic diagram was developed into a lumped mass model from the mechanical drawing. Three differential equations were derived according to the schematic diagram. A Simulink diagram was created using MATLAB to represent the three equations. System parameters, including spring constants and masses, are derived in detail from the physical system. The model can be used for further analysis via computer simulation in predicting dynamic response in its main docking direction, i.e., up-and-down motion.

Keywords: stewart platform, docking operation, spacecraft, spring constant

Procedia PDF Downloads 194

Authors: Tian Lan, Yixiang Wang, Wenxin Tai, Yilan Lyu, Zufeng Wu

Abstract:

The monaural speech enhancement task in the time-frequencydomain has a myriad of approaches, with the stacked con-volutional neural network (CNN) demonstrating superiorability in feature extraction and selection. However, usingstacked single convolutions method limits feature represen-tation capability and generalization ability. In order to solvethe aforementioned problem, we propose an attention-basedadaptive convolutional network that integrates the multi-scale convolutional operations into a operation-specific blockvia input dependent attention to adapt to complex auditoryscenes. In addition, we introduce a two-stage progressivelearning method to enlarge the receptive field without a dra-matic increase in computation burden. We conduct a series ofexperiments based on the TIMIT corpus, and the experimen-tal results prove that our proposed model is better than thestate-of-art models on all metrics.

Keywords: speech enhancement, adaptive convolu-tion, progressive learning, time-frequency domain

Procedia PDF Downloads 118

Authors: 李佳翰, CHIA-HAN LEE

Abstract:

Without energy, the economy would grind to a halt. Germany's prosperity and security depend on a reliable and affordable energy supply. In recent years, Germany's energy policy has undergone major changes. Due to the sharp turn in energy, Germany cannot extend the service of nuclear power plants and can only find a rapid transition energy source: natural gas for a limited time. This study attempts to use processes of decision entrapment behavior and document analysis to explain research questions. Through primary and secondary information such as official reports, parliamentary minutes, media interview records, and speech records, the author sorted out the important events experienced by the three coalition governments (Gerhard Schröder, Angela Merkel, and Olaf Scholz) and the relationship between Nord Stream 1 and Nord Stream 2 with primary and secondary sources. Also, compare it with the processes of decision entrapment behavior, which designed in this study, and divide it into four stages to explore its key elements one by one. In this regard, the following conclusions are drawn: First, from the perspective of processes of decision entrapment behavior, Merkel’s government firmly believes that she can overcome difficulties because of her past experience in crisis management capabilities. However, the outbreak of war between Ukraine and Russia was beyond Merkel's planning. Second, in the face of the crisis, the Scholz’s government increased the import of natural gas from other countries and began to import liquefied natural gas to make up for the energy gap of Russian natural gas.

Keywords: german research, nord stream gas pipeline, energy policy, processes of decision entrapment behavior

Procedia PDF Downloads 38

Authors: Krzysztof Rafał, Weronika Radziszewska, Hubert Biedka, Oskar Grabowski, Krzysztof Mik

Abstract:

We present a method to choose energy storage technologies and their parameters for the economic operation of a microgrid. A grid-connected system with local loads and PV generation is assumed, where an energy storage system (ESS) is attached to minimize energy cost by providing energy balancing and arbitrage functionalities. The ESS operates in a hybrid configuration and consists of two unique technologies operated in a coordinated way. Based on given energy profiles and economical data a model calculates financial flow for ESS investment, including energy cost and ESS depreciation resulting from degradation. The optimization strategy proposes a hybrid set of two technologies with their respective power and energy ratings to minimize overall system cost in a given timeframe. Results are validated through microgrid simulations using real-life input profiles.

Keywords: energy storage, hybrid energy storage, cost-benefit analysis, microgrid, battery sizing

Procedia PDF Downloads 210

Authors: S. Naveen, V. Sivasubramanian

Abstract:

A modeling theory is proposed to consider the vaporization of LNG during its contact with water following its release from an underwater source. The spillage of LNG underwater can lead to a decrease in the surface temperature of water and subsequent freezing. This can in turn affect the heat flux distribution from the released LNG onto the water surrounding it. The available models predict the rate of vaporization considering the surface of contact as a solid wall, and considering the entire phenomena as a solid-liquid operation. This assumption greatly under-predicted the overall heat transfer on LNG water interface. The vaporization flux would first decrease during the film boiling, followed by an increase during the transition boiling and a steady decrease during the nucleate boiling. A superheat theory is introduced to enhance the accuracy in the prediction of the heat transfer between LNG and water. The work suggests that considering the superheat theory can greatly enhance the prediction of LNG vaporization on underwater releases and also help improve the study of overall thermodynamics.

Keywords: evaporation rate, heat transfer, LNG vaporization, underwater LNG release

Procedia PDF Downloads 433

Authors: Yasam Palguna, Rajesh Korla

Abstract:

The efficiency of thermally operated systems can be improved by increasing the operating temperature, thereby decreasing the fuel consumption and carbon footprint. Hence, there is a continuous need for replacing the existing materials with new alloys with higher temperature working capabilities. During the last decade, multi principal element alloys, commonly known as high entropy alloys are getting more attention because of their superior high temperature strength along with good high temperature corrosion and oxidation resistance, The present work focused on the microstructure and high temperature tensile behavior of Al0.2CoCrFeNiMo0.5 high entropy alloy (HEA). Wrought Al0.2CoCrFeNiMo0.5 high entropy alloy, produced by vacuum induction melting followed by thermomechanical processing, is tested in the temperature range of 200 to 900oC. It is exhibiting very good resistance to softening with increasing temperature up to 700oC, and thereafter there is a rapid decrease in the strength, especially beyond 800oC, which may be due to simultaneous occurrence of recrystallization and precipitate coarsening. Further, it is exhibiting superplastic kind of behavior with a uniform elongation of ~ 275 % at 900 oC temperature and 1 x 10-3 s-1 strain rate, which may be due to the presence of fine stable equi-axed grains. Strain rate sensitivity of 0.3 was observed, suggesting that solute drag dislocation glide might be the active mechanism during superplastic kind of deformation. Post deformation microstructure suggesting that cavitation at the sigma phase-matrix interface is the failure mechanism during high temperature deformation. Finally, high temperature properties of the present alloy will be compared with the contemporary high temperature materials such as ferritic, austenitic steels, and superalloys.

Keywords: high entropy alloy, high temperature deformation, super plasticity, post-deformation microstructures

Procedia PDF Downloads 160

Authors: Rouzbeh Ramezani, Renzo Di Felice

Abstract:

Nowadays, removal of CO₂ as one of the major contributors to global warming using alternative solvents with high CO₂ absorption efficiency, is an important industrial operation. In this study, three amines, including 2-methylpiperazine, potassium sarcosinate and potassium lysinate as potential additives, were added to the potassium carbonate solution as a base solvent for CO₂ capture. In order to study the absorption performance of CO₂ in terms of loading capacity of CO₂ and absorption rate, the absorption experiments in a blend of additives with potassium carbonate were carried out using the vapor-liquid equilibrium apparatus at a temperature of 313.15 K, CO₂ partial pressures ranging from 0 to 50 kPa and at mole fractions 0.2, 0.3, and 0.4. Furthermore, the performance of CO₂ absorption in these blend solutions was compared with pure monoethanolamine and with pure potassium carbonate. Finally, a correlation with good accuracy was developed using the nonlinear regression analysis in order to predict CO₂ loading capacity.

Keywords: absorption rate, carbon dioxide, CO2 capture, global warming, loading capacity

Procedia PDF Downloads 276