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Inventions, Volume 7, Issue 3 (September 2022) – 23 articles

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Article
Computer Flow Simulation and Verification for Turbine Blade Channel Formed by the C-90-22 A Profile
Inventions 2022, 7(3), 68; https://doi.org/10.3390/inventions7030068 - 04 Aug 2022
Viewed by 267
Abstract
Currently, software products for numerical simulation of fluid dynamics processes (Ansys, Star CCM+, Comsol) are widely used in the power engineering industry when designing new equipment. However, computer simulation methods embedded in proprietary software products make specialists choose grid settings, boundary conditions, and [...] Read more.
Currently, software products for numerical simulation of fluid dynamics processes (Ansys, Star CCM+, Comsol) are widely used in the power engineering industry when designing new equipment. However, computer simulation methods embedded in proprietary software products make specialists choose grid settings, boundary conditions, and a solver providing the minimal deviation from experimental data with the maximal calculation speed. This paper analyzes the influence of the main grid settings and boundary conditions in the Ansys software package on the error in the computer simulation of flows in standard elements of power equipment and gives recommendations for their optimal choice. As standard elements were considered blade turbine channels formed by C-90-22 A profiles. Full article
Article
Using Drones for Thermal Imaging Photography and Building 3D Images to Analyze the Defects of Solar Modules
Inventions 2022, 7(3), 67; https://doi.org/10.3390/inventions7030067 - 02 Aug 2022
Viewed by 256
Abstract
In this research, drones were used to capture thermal images and detect different types of failure of solar modules, and MATLAB® image analysis was also conducted to evaluate the health of the solar modules. The processes included image acquisition and transmission by [...] Read more.
In this research, drones were used to capture thermal images and detect different types of failure of solar modules, and MATLAB® image analysis was also conducted to evaluate the health of the solar modules. The processes included image acquisition and transmission by drone, grayscale conversion, filtering, 3D image construction, and analysis. The analyzed targets were the solar modules installed on buildings. The results showed that the employment of drones to monitor solar module farms could significantly improve inspection efficiency. Moreover, by combining the mean and median filtering techniques, an innovative box filtering method was successfully created. Additionally, this study compared the differences between the mean, median, and box filtering techniques, and proved that the 3D image improved by box filtering is a more convenient and accurate way to check the health of solar modules than the mean and median filtering methods. In addition, this new method can simplify the maintenance process, as it helps maintenance personnel to determine whether to replace the solar modules on site, achieving the goal of power generation efficiency enhancement. It is worth noting that 3D image recognition technology can enhance the clarity of thermal images, thereby providing maintenance personnel with better defect diagnosis capability. It is also able to provide the temperature value of the defect zone, and to indicate the scale of defects through the cumulative temperature chart, so the 3D image is qualified as a quantitative and qualitative indicator. The analysis of the transmitted image is innovative that it not only can locate the defect area of the module, but also can display the temperature of the module, providing more information for maintenance personnel. Full article
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Article
Feasibility Study of the CO2 Regenerator Parameters for Oxy-Fuel Combustion Power Cycle
Inventions 2022, 7(3), 66; https://doi.org/10.3390/inventions7030066 - 29 Jul 2022
Viewed by 257
Abstract
The atmosphere carbon dioxide content grows subsequently due to anthropogenic factors. It may be considerably mitigated by the development of thermal power plants with near zero emissions. A promising way is the transition to the semi-closed oxy-fuel combustion power cycles with carbon dioxide [...] Read more.
The atmosphere carbon dioxide content grows subsequently due to anthropogenic factors. It may be considerably mitigated by the development of thermal power plants with near zero emissions. A promising way is the transition to the semi-closed oxy-fuel combustion power cycles with carbon dioxide and water vapor mixture as a working fluid. However, their wide implementation requires reduction of the metal consumption for the highly efficient regeneration system. This paper discloses the results of feasibility study for the regeneration system of the prospective oxy-fuel combustion power plant. The effect of operating parameters on the cycle energy efficiency, overall dimensions, and the cost of the regenerator was determined. Underheating increase in the regenerator by 1 °C leads to the net efficiency factor drop of the oxy-fuel combustion power cycle by 0.13% at average and increases fuel costs by 0.28%. Increase of pressure drop in the hot channel by 1% leads to efficiency drop by 0.14%. The optimum set of design and operating parameters of the feed heating system has been determined, which ensures the best technical and economic indicators of electrical power generation: the minimum cumulative costs are achieved when underheating in the regenerator is 20 °C and pressure drop in the hot channel is 4%, under the use of S-shaped fins channels. Full article
(This article belongs to the Special Issue Thermodynamic and Technical Analysis for Sustainability (Volume 2))
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Article
Development of a Mathematical Model for Solid Fuel Gasification and Its Sensitivity Analysis
Inventions 2022, 7(3), 65; https://doi.org/10.3390/inventions7030065 - 29 Jul 2022
Viewed by 238
Abstract
Within the framework of this study, a brief review of the gasification technology was carried out, the best types of blowing agents and gasification methods used in terms of efficiency and environmental safety were identified, and a mathematical model of a steam–oxygen gasifier [...] Read more.
Within the framework of this study, a brief review of the gasification technology was carried out, the best types of blowing agents and gasification methods used in terms of efficiency and environmental safety were identified, and a mathematical model of a steam–oxygen gasifier was developed in the MS Excel software package. The authors paid special attention to the consideration of the effect of changing the input parameters of the syngas, such as the temperature and relative mass flow rate of steam and oxygen, on the heat of the combustion of the produced syngas. As a result of the research, methods for increasing the heat of the combustion of the syngas and the conditions for using the described methods were formulated. The work also revealed the optimal ratios of the blowing agents and solid fuel supplied for gasification and presented the output parameters of the produced generator gas, including the heat of combustion of the gas, the gas temperature, and the gasification efficiency. Computer simulation models of the gasifier and gasification process were the basis for the analysis of a combined cycle (CC) facility with an integrated solid fuel gasifier. The heat flow thermodynamic analysis shows that the gasification steam bleeding from the turbine is the best solution for the improvement of cycle efficiency. Full article
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Article
Research and Development of Hybrid Power Units Heat Flow Diagrams with Cooled High-Temperature Steam Turbines
Inventions 2022, 7(3), 64; https://doi.org/10.3390/inventions7030064 - 27 Jul 2022
Viewed by 221
Abstract
Fossil fuel thermal power plants account for almost 60% of Russian electricity and heat. Steam turbine units make almost 80% of this amount. The main method for steam turbine unit efficiency improvement is the increase in the initial steam parameters’ temperature and pressure. [...] Read more.
Fossil fuel thermal power plants account for almost 60% of Russian electricity and heat. Steam turbine units make almost 80% of this amount. The main method for steam turbine unit efficiency improvement is the increase in the initial steam parameters’ temperature and pressure. This reduces fossil fuel consumption and harmful emissions but requires the application of heat-resistant steel. The improvement in steel’s heat resistance leads to a non-linear price increase, and the larger the temperature increase, the more the steel costs. One of the methods of improving efficiency without a significant increase in the capital cost of equipment is an external combustion chamber. These allow an increase in the steam temperature outside the boiler without the need to use heat-resistant alloys for boiler superheaters and steam pipelines between the boiler and the steam turbine. The most promising is hydrogen–oxygen combustion chambers, which produce steam with high purity and parameters. To reduce the cost of high-temperature steam turbines, it is possible to use a cooling system with the supply of a steam coolant to the most thermally stressed elements. According to the calculations, the efficiency reduction of a power unit due to the turbine cooling is 0.6–1.27%. The steam superheating up to 720 °C in external combustion chambers instead of a boiler unit improves the unit efficiency by 0.27%. At the initial steam temperatures of 800 °C, 850 °C, and 900 °C, the unit efficiency reduction caused by cooling is 4.09–5.68%, 7.47–9.73%, and 8.28–10.04%, respectively. Full article
(This article belongs to the Special Issue Thermodynamic and Technical Analysis for Sustainability (Volume 2))
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Article
Technological Solutions in the Field of Production and Use of Hydrogen Fuel to Increase the Thermal Efficiency of Steam Turbine TPPs
Inventions 2022, 7(3), 63; https://doi.org/10.3390/inventions7030063 - 26 Jul 2022
Viewed by 222
Abstract
The paper discusses technological solutions in the field of production and use of hydrogen fuel, the combustion of which, in a steam-oxygen environment, can significantly increase the initial parameters of the steam turbine cycle and, thus, increase the thermal efficiency of traditional steam [...] Read more.
The paper discusses technological solutions in the field of production and use of hydrogen fuel, the combustion of which, in a steam-oxygen environment, can significantly increase the initial parameters of the steam turbine cycle and, thus, increase the thermal efficiency of traditional steam turbine thermal power plants. A study of technologies for the industrial production of hydrogen has been carried out. An analysis of the technical and economic features of hydrogen production technologies for use in the electric power industry showed that the most promising method is electrolysis, which makes it possible to obtain inexpensive hydrogen during hours of low demand for electricity or cogeneration of heat and electricity when electricity is a by-product. It is shown that in order to increase the power and efficiency of steam turbine TPPs, it is important to use external steam superheating from an external source of thermal energy, thus providing intermediate overheating of the working fluid by connecting an additional cycle with a higher equivalent initial temperature to the main steam turbine cycle. We have established that if we use hydrogen as a thermal energy source, the absolute efficiency of the steam turbine cycle can be increased up to 54%, taking into account the regenerative heating of feed water. In this case, at an overheating temperature equal to tnn = 760 °C, the absolute efficiency of the cycle is virtually equal to that of a CCGT unit operating at the initial gas temperature t0 = 1350 °C. At the same time, while maintaining the boiler performance, the rated capacity of the steam turbine power unit is increased by 12%. In addition, the study pays attention to the problem of increasing the power consumption of TPPs for the auxiliaries, as required to compress hydrogen and oxygen up to a pressure higher than that in the steam pipeline where the combustion chamber is installed. Our calculations have allowed us to conclude that, for the case of installing the combustion chamber in live steam, the share of additional power spent for auxiliaries should be 7%, whereas the main share of power is consumed for compressing hydrogen—94%. Despite the identified shortcomings, an economic analysis of the process of hydrogen production at TPP by electrolysis and its further use for intermediate overheating in steam turbines in order to increase their efficiency showed the effectiveness of this solution. Full article
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Article
Invention of a Medical Glove Durability Assessment Device
Inventions 2022, 7(3), 62; https://doi.org/10.3390/inventions7030062 - 22 Jul 2022
Viewed by 304
Abstract
Healthcare workers across the globe rely on medical gloves to prevent the transfer of harmful bacteria and viruses between themselves and their patients. Unfortunately, due to the lack of an in-use durability standard for medical gloves by the American Society for Testing and [...] Read more.
Healthcare workers across the globe rely on medical gloves to prevent the transfer of harmful bacteria and viruses between themselves and their patients. Unfortunately, due to the lack of an in-use durability standard for medical gloves by the American Society for Testing and Materials, many of these gloves are of low quality and are easily torn or punctured, exposing wearers and patients to potentially deadly diseases. To solve this problem, a device that automatically detects material failures the size of a pinhole during active testing was invented. The device consists of a prosthetic hand, vacuum pump, mobile textured roller, pressure sensor, and liquid spray system. It works by creating a vacuum inside the glove and repeatedly moving the textured roller into contact with the fingertips, which, on the prosthetic hand, are porous. When a glove perforates, the vacuum is broken, pressure within the hand rapidly increases, and the operator is alerted on a touchscreen that the glove has failed. In addition, the liquid spray system allows the user to test gloves in “real world” conditions, because healthcare workers often come into contact with liquids that may alter glove durability. As a preliminary test of the device’s accuracy, five nitrile and five latex exam gloves were tested using the system’s default settings. Natural latex is known to be the highest performing glove material, so the nitrile gloves were expected to fail more quickly than the latex gloves. The test results concur with this expected order of failure: nitrile first, with an average failure time of 300 s and 42 average number of roller touches, followed by natural latex, with an average failure time of 2206 s and 300 average number of roller touches. These results provide evidence that the device accurately ranks glove durability, and therefore could be used to develop an ASTM durability standard and improve the quality of gloves made from different polymers. Full article
(This article belongs to the Section Inventions and innovation in Biotechnology and Materials)
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Article
Biosafety Construction Composite Based on Iron Oxide Nanoparticles and PLGA
Inventions 2022, 7(3), 61; https://doi.org/10.3390/inventions7030061 - 20 Jul 2022
Viewed by 362
Abstract
Nanocomposites based on polymers and nanoparticles are used in agriculture for photoconversion of solar radiation, as a basis for covering material, as a packaging material, and as functional films. At the same time, nanocomposites are almost never used in agriculture as biosafe structural [...] Read more.
Nanocomposites based on polymers and nanoparticles are used in agriculture for photoconversion of solar radiation, as a basis for covering material, as a packaging material, and as functional films. At the same time, nanocomposites are almost never used in agriculture as biosafe structural materials. In this work, we have developed a technology for obtaining a nanocomposite based on PLGA and iron oxide nanoparticles. The nanocomposite has unique physical and chemical properties and also exhibits pronounced antibacterial properties at a concentration of iron oxide nanoparticles of more than 0.01%. At the same time, the nanocomposite does not affect the growth and development of pepper and is biocompatible with mammalian cells. Nanocomposites based on PLGA and iron oxide nanoparticles can be an attractive candidate for the manufacture of structural and packaging materials in agriculture. Full article
(This article belongs to the Collection Feature Innovation Papers)
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Article
The Application of X-ray Micro-CT in the Study of HTS Tape Coils
Inventions 2022, 7(3), 60; https://doi.org/10.3390/inventions7030060 - 14 Jul 2022
Viewed by 292
Abstract
In the process of manufacturing products from high-temperature superconductors (HTS), quality control must be carried out. Traditionally, for HTS coils, electrical tests are carried out to determine critical current. In the case of an unacceptable result, it is necessary to determine the cause. [...] Read more.
In the process of manufacturing products from high-temperature superconductors (HTS), quality control must be carried out. Traditionally, for HTS coils, electrical tests are carried out to determine critical current. In the case of an unacceptable result, it is necessary to determine the cause. Therefore, it is necessary to develop nondestructive testing methods. This article proposes a technology for manufacturing quality evaluation. It is based on determining the actual location of the tape and the gaps between the turns and rows of the coil and analyzing these values. For this purpose, samples were scanned using computed tomography (CT) with a Nordson Dage XD7600NT X-ray inspection system with a μCT module. The obtained data were analyzed using VolumeGraphics VGStudio 2.2 software. Furthermore, the proposed technology can be used as part of a predictive analysis of the state of HTS coils in the windings of electrical machines. Full article
(This article belongs to the Collection Feature Innovation Papers)
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Article
The Strategy of Factors Influencing Learning Satisfaction Explored by First and Second-Order Structural Equation Modeling (SEM)
Inventions 2022, 7(3), 59; https://doi.org/10.3390/inventions7030059 - 14 Jul 2022
Viewed by 440
Abstract
The goal of this research was to create a partial least square structural equation model (PLS-SEM) with a second-order structural model to investigate the interaction between research-based methodologies and relationship factors that significantly influence learning satisfaction among university students. The instruments used in [...] Read more.
The goal of this research was to create a partial least square structural equation model (PLS-SEM) with a second-order structural model to investigate the interaction between research-based methodologies and relationship factors that significantly influence learning satisfaction among university students. The instruments used in this study were a simple random sampling technique for structural equation model (SEM) analysis, while a quantitative process of survey data collection was manipulated through SPSS and Smart-PLS. The presented study attempted to explore whether teachers’ strategies are linked with their students for the students’ learning satisfaction. Thus, it represents the demands and expectations of two statistically significant common phenomena: research-based components and relationship approach components. This set of teaching techniques encourages university students and enhances their learning satisfaction. Moreover, this study explored teaching strategies that influence factors having a directly significant influence on learning satisfaction at university level. Each factor measures the relationship’s construct, proven to be a second-order SEM reflective model that is statistically significant. Our study explored learning satisfaction as an integral part of teaching strategies, by first- and second-order structural equation modeling, supported by students’ expectations, and the study’s empirical results provide potential implications for learning satisfaction. Full article
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Article
Design and Stability Analysis of an Offshore Floating Multi-Wind Turbine Platform
Inventions 2022, 7(3), 58; https://doi.org/10.3390/inventions7030058 - 08 Jul 2022
Viewed by 336
Abstract
The multi-wind turbine platform technology has the potential to harness the significant source of offshore wind energy in deep waters. However, the wake interference between the turbines on the multi-wind turbine platform can cause a reduction in power production; hence, it is important [...] Read more.
The multi-wind turbine platform technology has the potential to harness the significant source of offshore wind energy in deep waters. However, the wake interference between the turbines on the multi-wind turbine platform can cause a reduction in power production; hence, it is important to study the wake effects in the initial phase of the design. This paper studies the effects of wake interference between the wind turbines on three different platform configurations to find a suitable configuration for the wind turbines on a multi-turbine platform. The analytical Larsen wake model and computational fluid dynamics (CFD) simulations are used for evaluating the wake effects. The platform configuration required for the wind turbines is determined based on the results of wake effects, and then a novel platform is designed. The free-floating stability behavior of the multi-wind turbine platform is analyzed using the hydrostatic analysis of the modeled platform. The wave-body interaction between the platform and the waves is predicted using the hydrodynamic analysis. A preliminary cost analysis of the multi-turbine platform concept is evaluated and compared with a single wind turbine floating concept. The results showed that the presented design is a promising concept that can enhance the offshore wind industry. Full article
(This article belongs to the Topic Marine Renewable Energy)
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Article
Wind Variation near the Black Sea Coastal Areas Reflected by the ERA5 Dataset
Inventions 2022, 7(3), 57; https://doi.org/10.3390/inventions7030057 - 07 Jul 2022
Viewed by 372
Abstract
In the context of the European Green Deal implementation, it is expected that there will be an increase in number of the wind farms located near the coastal areas in order to support this initiative. The Black Sea represents an important source of [...] Read more.
In the context of the European Green Deal implementation, it is expected that there will be an increase in number of the wind farms located near the coastal areas in order to support this initiative. The Black Sea represents an important source of wind energy, and as a consequence, in the present work the regional wind resources (onshore and offshore) are evaluated by considering a total of 20 years of ERA5 wind data covering the 20-year time interval from January 2002 to December 2021. From a general perspective, it is clear that the offshore areas (100 km from the shoreline) are defined by much higher wind speed values than in the onshore, reaching an average of 8.75 m/s for the points located on the western sector. During the winter, these values can go up to 8.75 m/s, with the mention that the northern sectors from Ukraine and Russia may easily exceed 8 m/s. In terms of the wind turbines’ selection, for the offshore areas defined by consistent wind resources, generators will be considered that are defined by a rated wind speed of 11 m/s. Finally, we can mention that a theoretical offshore wind turbine of 20 MW can reach a capacity factor located between 20.9 and 48.3%, while a maximum annual electricity production of 84.6 GWh may be obtained from the sites located near the Romanian and Ukrainian sectors, respectively. Full article
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Article
Research and Development of Trinary Power Cycles
Inventions 2022, 7(3), 56; https://doi.org/10.3390/inventions7030056 - 04 Jul 2022
Viewed by 352
Abstract
The most effective and environmentally safe fossil fuel power production facilities are the combined cycle gas turbine (CCGT) ones. Electric efficiency of advanced facilities is up to 58% in Russia and up to 64% abroad. The further improvement of thermal efficiency by increase [...] Read more.
The most effective and environmentally safe fossil fuel power production facilities are the combined cycle gas turbine (CCGT) ones. Electric efficiency of advanced facilities is up to 58% in Russia and up to 64% abroad. The further improvement of thermal efficiency by increase of the gas turbine inlet temperature (TIT) is limited by performance of heat resistance alloys that are used for the hot gas path components and the cooling system efficiency. An alternative method for the CCGT efficiency improvement is utilization of low potential heat of the heat recovery steam generator (HRSG) exhaust gas in an additional cycle operating on a low-boiling heat carrier. This paper describes a thermodynamic analysis of the transition from binary cycles to trinary ones by integration of the organic Rankine cycle (ORC). A mathematical model of a cooled gas turbine plant (GT) has been developed to carry out calculations of high-temperature energy complexes. Based on the results of mathematical modeling, recommendations were made for the choice of the structure and parameters of the steam turbine cycle, as well as the ORC, to ensure the achievement of the maximum thermal efficiency of trinary plants. It is shown that the transition from a single pressure CCGT to a trinary plant allows the electric power increase from 213.4 MW to 222.7 MW and the net efficiency increase of 2.14%. The trinary power facility has 0.45% higher efficiency than the dual pressure CCGT. Full article
(This article belongs to the Collection Feature Innovation Papers)
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Article
Extending DC Bus Signaling and Droop Control for Hybrid Storage Units to Improve the Energy Management and Voltage Regulation
Inventions 2022, 7(3), 55; https://doi.org/10.3390/inventions7030055 - 30 Jun 2022
Viewed by 381
Abstract
DC bus-voltage signaling (DBS) and droop control are often used in DC nano and microgrids with decentralized distributed energy resources (DERs). This technique effectively enforces the appropriate contributions of power sources and energy storage systems (ESSs) in steady-state situations. The usage of super [...] Read more.
DC bus-voltage signaling (DBS) and droop control are often used in DC nano and microgrids with decentralized distributed energy resources (DERs). This technique effectively enforces the appropriate contributions of power sources and energy storage systems (ESSs) in steady-state situations. The usage of super capacitors (SCs) in conjunction with batteries in a hybrid energy storage system (HESS) has recently been shown to reduce the influence of high and fast current changes on the losses and lifetime of the battery units. However, regulating the HESS as a single unit eliminates the SC’s potential contribution in improving power quality in a DC nanogrid due to its high-power capabilities. This work discusses employing a dual-droop coefficient to expand DC bus signaling and droop control by introducing a second droop constant in the range of the ESS’s droop constant. The suggested droop constant allows the SC to participate in power-sharing in the steady state. The voltage regulation will improve by decreasing the DC bus voltage variation with the load or power variation in the DC nanogrid. Furthermore, in the droop zone, the battery’s current variation is less, resulting in a smoother transition in the battery current. In addition to this, the contribution that SCs make to the slow component is variable, which is something that might be accomplished by having a changing threshold voltage in the I vs. V curve. Full article
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Article
TiO2/Au/TiO2 Plasmonic Photocatalysts: The Influence of Titania Matrix and Gold Properties
Inventions 2022, 7(3), 54; https://doi.org/10.3390/inventions7030054 - 30 Jun 2022
Viewed by 360
Abstract
Plasmonic photocatalysts have gained more and more attention because of possible applications for solar energy conversion, environmental decontamination, and water treatment. However, the activity under visible light is usually very low, and the property-governed activity as well as the mechanisms are not fully [...] Read more.
Plasmonic photocatalysts have gained more and more attention because of possible applications for solar energy conversion, environmental decontamination, and water treatment. However, the activity under visible light is usually very low, and the property-governed activity as well as the mechanisms are not fully understood yet. Accordingly, this study examines four different titania photocatalysts (anatase and rutile with fine and large crystallites) modified with gold by photodeposition. Three kinds of samples were prepared, as follows: (i) gold-modified titania (Au/TiO2), (ii) physically mixed Au/TiO2 samples (Au/TiO2(1) + Au/TiO2(2)), and (iii) Au/(TiO2(1) + Au/TiO2(2)) samples, prepared by subsequent deposition of gold on the mixture of bare and gold-modified titania. In total, twelve samples were prepared and well characterized, including diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM). The photocatalytic activity was examined in three reaction systems: (i) methanol dehydrogenation during gold photodeposition under UV/vis irradiation, (ii) oxidative decomposition of acetic acid (UV/vis), and (iii) oxidation of 2-propanol to acetone under visible light irradiation (λ > 450 nm). It was found that during subsequent deposition, gold is mainly formed on the surface of pre-deposited Au nanoparticles (NPs), localized on fine titania NPs, through the electrostatic attractions (negatively charged gold resulting from photogenerated electrons’ accumulation). This gold aggregation, though detrimental for UV activity (many “naked” large titania with low activity), is highly beneficial for vis activity because of efficient light harvesting and increased interface between gold and titania (gold deposits surrounded by fine titania NPs). Moreover, it was found that rutile is more active than anatase for plasmonic photocatalysis, probably due to easier electron transfer from gold via titania to adsorbed oxygen (more negative conduction band), which might hinder the back reaction (electron transfer: Au→TiO2→Au). Full article
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Communication
Perspectives on the Barriers to Nuclear Power Generation in the Philippines: Prospects for Directions in Energy Research in the Global South
Inventions 2022, 7(3), 53; https://doi.org/10.3390/inventions7030053 - 29 Jun 2022
Cited by 1 | Viewed by 511
Abstract
This paper offers a discussion on the social dimensions of the barriers to nuclear power generation in the country. The aim of this paper is to contribute to the literature by identifying the barriers to nuclear power generation in the Philippines and offering [...] Read more.
This paper offers a discussion on the social dimensions of the barriers to nuclear power generation in the country. The aim of this paper is to contribute to the literature by identifying the barriers to nuclear power generation in the Philippines and offering perspectives on the social relevance of potentially adding nuclear sources to the country’s energy mix. Given the contemporary relevance of the energy transitions globally, this work builds on the available sources over the past decade concerning nuclear energy technology in the Philippines and provides further discussions on the diverse barriers to the country’s energy transition pathway. Findings present barriers related to politics, policy, infrastructure, technical capacities, environment and information. The differences in priorities and values concerning nuclear energy reflect that the barriers to nuclear energy generation in the Philippines are social as much as technical. Based on the findings and descriptions of the current discussions on Philippine energy generation, this work provides some key points for consideration in order to deploy nuclear power plants in the country. These recommendations, however, are not definitive measures and are still subject to local conditions that may arise. This study hopes to be instructive to other countries in terms of further reflecting on the social dimensions of the barriers to nuclear energy generation. Full article
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Article
Improvement of Fault Current Calculation and Static Security Risk for Droop Control of the Inverter-Interfaced DG of Grid-Connected and Isolated Microgrids
Inventions 2022, 7(3), 52; https://doi.org/10.3390/inventions7030052 - 29 Jun 2022
Viewed by 298
Abstract
The contribution current of an inverter-interfaced distributed generator unit during a fault is one of the significant challenges for two modes: grid-connected and isolated AC microgrid. For this challenge, this article is aimed to study two methods of fault current calculation for two [...] Read more.
The contribution current of an inverter-interfaced distributed generator unit during a fault is one of the significant challenges for two modes: grid-connected and isolated AC microgrid. For this challenge, this article is aimed to study two methods of fault current calculation for two modes: grid-connected and isolated microgrids. These methods include a virtual equivalent impedance and a proposed method. The proposed method is a new technique for calculating the fault current contribution depending on the droop control of inverter-interfaced DG. The proposed method can control the contribution short-circuit current of DG within its limit (2 p.u.) where it is dependent on the voltage value of the DG bus to calculate the short circuit current of DG by using the control criterion. Static security risk and load shedding are calculated after fault clearance using an operation scenario in which the distribution system will be divided into small subsystems and is then grid-connected and isolated due to the removal of the faulted bus by protection devices. The proposed technique is applied to a standard IEEE 33-bus distribution network with five DGs. The results show that the contribution current of inverter-interfaced DG during the fault has more effects than the fault current of the nearest faulted bus to the DG bus. The proposed technique improves the calculated fault current value by about 30% for the grid-connected microgrid and by about 50% for the isolated microgrid from its value of the virtual impedance method. The static security risk is improved after load shedding. The static security risk improved by about 0.025%. Full article
(This article belongs to the Special Issue Microgrids: Protection, Cyber Physical Issues, and Control)
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Article
Gait Cycle Monitoring System Based on Flexiforce Sensors
Inventions 2022, 7(3), 51; https://doi.org/10.3390/inventions7030051 - 28 Jun 2022
Viewed by 405
Abstract
Medical technology companies have focused on gait analysis and monitoring for several years due to their importance in the diagnosis of various movement abnormalities. Studying pressure distribution on the foot is very important for the detection of abnormalities, unwanted symptoms, and consequences. This [...] Read more.
Medical technology companies have focused on gait analysis and monitoring for several years due to their importance in the diagnosis of various movement abnormalities. Studying pressure distribution on the foot is very important for the detection of abnormalities, unwanted symptoms, and consequences. This paper aims to design a wearable, low-cost, and real-time gait cycle monitoring system, based on a Flexiforce sensor. In the proposed design, eight force sensors were attached to the insole to estimate the pressure distribution on the foot. Pressure distribution monitoring helps in the estimation of foot disorders and assists in the design of medical shoes for manipulating pressure into the right positions. Sensors were connected to an appropriate microcontroller for real-time monitoring. MATLAB was used to visualize and simulate the real-time plantar pressure variation through static and dynamic states. The obtained experimental results show that the system was stable in both static and dynamic measurements, which could be used to estimate the pressure distribution on the foot. Full article
(This article belongs to the Section Inventions and innovation in Biotechnology and Materials)
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Article
Mass Transfer Effects on the Mucus Fluid with Pulsatile Flow Influence of the Electromagnetic Field
Inventions 2022, 7(3), 50; https://doi.org/10.3390/inventions7030050 - 24 Jun 2022
Viewed by 435
Abstract
The influence of pulsatile flow on the oscillatory motion of an incompressible conducting boundary layer mucus fluid flowing through porous media in a channel with elastic walls is investigated. The oscillatory flow is treated as a cyclical time-dependent flux. The Laplace transform method [...] Read more.
The influence of pulsatile flow on the oscillatory motion of an incompressible conducting boundary layer mucus fluid flowing through porous media in a channel with elastic walls is investigated. The oscillatory flow is treated as a cyclical time-dependent flux. The Laplace transform method using the Womersley number is used to solve non-linear equations controlling the motion through porous media under the influence of an electromagnetic field. The theoretical pulsatile flow of two liquid phase concurrent fluid streams, one kinematic and the other viscoelastic, is investigated in this study. To extend the model for various physiological fluids, we postulate that the viscoelastic fluid has several distinct periods. We also apply our analytical findings to mucus and airflow in the airways, identifying the wavelength that increases dynamic mucus permeability. The microorganism’s thickness, velocity, energy, molecular diffusion, skin friction, Nusselt number, Sherwood number, and Hartmann number are evaluated. Discussion is also supplied in various sections to investigate the mucosal flow process. Full article
(This article belongs to the Special Issue Recent Trends in Nanofluids III)
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Article
Calculation and Experimental Study of Low-Cycle Fatigue of Gas Turbine Engines Booster Drum
Inventions 2022, 7(3), 49; https://doi.org/10.3390/inventions7030049 - 23 Jun 2022
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Abstract
A calculation-experimental study of durability of titanium booster drum of gas turbine engine (GTE) was carried out. A methodology of experimental estimation of titanium component life of GTE using structurally similar elements (SSE) has been proposed. A series of three-dimensional calculations by the [...] Read more.
A calculation-experimental study of durability of titanium booster drum of gas turbine engine (GTE) was carried out. A methodology of experimental estimation of titanium component life of GTE using structurally similar elements (SSE) has been proposed. A series of three-dimensional calculations by the finite element method of SSE cut out of the finished part was carried out to estimate the strength of the booster drum. A methodology for testing the durability of SSE in the low-cycle fatigue (LCF) area was developed, and statistical processing of the test results was performed. Tests of SSE allowed carrying out advanced-edge assessment of the durability of a full-size drum, taking into account the manufacturing technology. Full article
(This article belongs to the Collection Feature Innovation Papers)
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Article
A Novel Solution for Day-Ahead Scheduling Problems Using the IoT-Based Bald Eagle Search Optimization Algorithm
Inventions 2022, 7(3), 48; https://doi.org/10.3390/inventions7030048 - 23 Jun 2022
Viewed by 478
Abstract
Advances in technology and population growth are two factors responsible for increasing electricity consumption, which directly increases the production of electrical energy. Additionally, due to environmental, technical and economic constraints, it is challenging to meet demand at certain hours, such as peak hours. [...] Read more.
Advances in technology and population growth are two factors responsible for increasing electricity consumption, which directly increases the production of electrical energy. Additionally, due to environmental, technical and economic constraints, it is challenging to meet demand at certain hours, such as peak hours. Therefore, it is necessary to manage network consumption to modify the peak load and tackle power system constraints. One way to achieve this goal is to use a demand response program. The home energy management system (HEMS), based on advanced internet of things (IoT) technology, has attracted the special attention of engineers in the smart grid (SG) field and has the tasks of demand-side management (DSM) and helping to control equality between demand and electricity supply. The main performance of the HEMS is based on the optimal scheduling of home appliances because it manages power consumption by automatically controlling loads and transferring them from peak hours to off-peak hours. This paper presents a multi-objective version of a newly introduced metaheuristic called the bald eagle search optimization algorithm (BESOA) to discover the optimal scheduling of home appliances. Furthermore, the HEMS architecture is programmed based on MATLAB and ThingSpeak modules. The HEMS uses the BESOA algorithm to find the optimal schedule pattern to reduce daily electricity costs, reduce the PAR, and increase user comfort. The results show the suggested system’s ability to obtain optimal home energy management, decreasing the energy cost, microgrid emission cost, and PAR (peak to average ratio). Full article
(This article belongs to the Special Issue Microgrids: Protection, Cyber Physical Issues, and Control)
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Article
Mobile Visual Servoing Based Control of a Complex Autonomous System Assisting a Manufacturing Technology on a Mechatronics Line
Inventions 2022, 7(3), 47; https://doi.org/10.3390/inventions7030047 - 22 Jun 2022
Viewed by 418
Abstract
The main contribution of this paper is the modeling and control for a complex autonomous system (CAS). It is equipped with a visual sensor to operate precision positioning in a technology executed on a laboratory mechatronics line. The technology allows the retrieval of [...] Read more.
The main contribution of this paper is the modeling and control for a complex autonomous system (CAS). It is equipped with a visual sensor to operate precision positioning in a technology executed on a laboratory mechatronics line. The technology allows the retrieval of workpieces which do not completely pass the quality test. Another objective of this paper is the implementation of an assisting technology for a laboratory processing/reprocessing mechatronics line (P/RML) containing four workstations, assisted by the following components: a complex autonomous system that consists of an autonomous robotic system (ARS), a wheeled mobile robot (WMR) PeopleBot, a robotic manipulator (RM) Cyton 1500 with seven degrees of freedom (7 DOF), and a mobile visual servoing system (MVS) with a Logitech camera as visual sensor used in the process of picking, transporting and placing the workpieces. The purpose of the MVS is to increase the precision of the RM by utilizing the look and move principle, since the initial and final positions of the CAS can slightly deviate from their trajectory, thus increasing the possibility of errors to appear during the process of catching and releasing the pieces. If the processed piece did not pass the quality test and has been rendered as defective, it is retrieved from the last station of the P/RML and transported to the first station for reprocessing. The control of the WMR is done using the trajectory-tracking sliding-mode control (TTSMC). The RM control is based on inverse kinematics model, and the MVS control is implemented with the image moments method. Full article
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Article
Incorporating Human Preferences in Decision Making for Dynamic Multi-Objective Optimization in Model Predictive Control
Inventions 2022, 7(3), 46; https://doi.org/10.3390/inventions7030046 - 21 Jun 2022
Viewed by 371
Abstract
We present a new two-step approach for automatized a posteriori decision making in multi-objective optimization problems, i.e., selecting a solution from the Pareto front. In the first step, a knee region is determined based on the normalized Euclidean distance from a hyperplane defined [...] Read more.
We present a new two-step approach for automatized a posteriori decision making in multi-objective optimization problems, i.e., selecting a solution from the Pareto front. In the first step, a knee region is determined based on the normalized Euclidean distance from a hyperplane defined by the furthest Pareto solution and the negative unit vector. The size of the knee region depends on the Pareto front’s shape and a design parameter. In the second step, preferences for all objectives formulated by the decision maker, e.g., 50–20–30 for a 3D problem, are translated into a hyperplane which is then used to choose a final solution from the knee region. This way, the decision maker’s preference can be incorporated, while its influence depends on the Pareto front’s shape and a design parameter, at the same time favorizing knee points if they exist. The proposed approach is applied in simulation for the multi-objective model predictive control (MPC) of the two-dimensional rocket car example and the energy management system of a building. Full article
(This article belongs to the Collection Feature Innovation Papers)
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