Inventions

22 pages, 8415 KiB

Open AccessArticle

Technical Requirements of Photovoltaic Inverters for Low Voltage Distribution Networks

by Krzysztof Chmielowiec, Łukasz Topolski, Mateusz Dutka, Aleks Piszczek, Zbigniew Hanzelka and Tomasz Rodziewicz

Inventions 2024, 9(4), 91; https://doi.org/10.3390/inventions9040091 - 16 Aug 2024

Viewed by 869

Abstract

The paper presents the results of an experimental study, which was conducted in 2021 and briefly presented at the conference CIGRE Paris Session 2022, as a part of a joint initiative for comparative studies of PV inverters, of AGH University of Science and [...] Read more.

The paper presents the results of an experimental study, which was conducted in 2021 and briefly presented at the conference CIGRE Paris Session 2022, as a part of a joint initiative for comparative studies of PV inverters, of AGH University of Science and Technology and Tauron Dystrybucja (Polish DSO). The study was performed on a representative sample of 29 brand new PV inverters, widely available for sale in the EU, from over 20 various manufacturers from and outside the EU. For the purposes of this research, all tested PV have been made available by their manufacturers or regional distributors, which confirms the origin of the devices from official distribution channels and their designation for the EU market. The conducted research covers the technical aspects of PV inverters’ operation and performance included in the NC RfG network code, technical standard EN-505049-1:2019, and internal regulations of distribution system operators governing PV inverter technical quality and its cooperation with the low-voltage distribution network. The national regulations may differ between individual EU member states. The paper describes the testing procedure, obtained results, conclusions, and recommendations for regulatory bodies and DSOs. Full article

(This article belongs to the Special Issue Recent Advances and Challenges in Emerging Power Systems: 2nd Edition)

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25 pages, 2254 KiB

Open AccessArticle

Exposing Data Leakage in Wi-Fi CSI-Based Human Action Recognition: A Critical Analysis

by Domonkos Varga

Inventions 2024, 9(4), 90; https://doi.org/10.3390/inventions9040090 - 15 Aug 2024

Viewed by 1177

Abstract

Wi-Fi channel state information (CSI)-based human action recognition systems have garnered significant interest for their non-intrusive monitoring capabilities. However, the integrity of these systems can be compromised by data leakage, particularly when improper dataset partitioning strategies are employed. This paper investigates the presence [...] Read more.

Wi-Fi channel state information (CSI)-based human action recognition systems have garnered significant interest for their non-intrusive monitoring capabilities. However, the integrity of these systems can be compromised by data leakage, particularly when improper dataset partitioning strategies are employed. This paper investigates the presence and impact of data leakage in three published Wi-Fi CSI-based human action recognition methods that utilize deep learning techniques. The original studies achieve precision rates of 95% or higher, attributed to the lack of human-based dataset splitting. By re-evaluating these systems with proper subject-based partitioning, our analysis reveals a substantial decline in performance, underscoring the prevalence of data leakage. This study highlights the critical need for rigorous dataset management and evaluation protocols to ensure the development of robust and reliable human action recognition systems. Our findings advocate for standardized practices in dataset partitioning to mitigate data leakage and enhance the generalizability of Wi-Fi CSI-based models. Full article

(This article belongs to the Section Inventions and Innovation in Design, Modeling and Computing Methods)

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10 pages, 1978 KiB

Open AccessArticle

Flow Rate Sensor inside Infusion Tube

by Hsiang-Chen Chui, Ying Xu, Zhiyuan Wang, Xianting Zhang, Rui Li and Kai-Rong Qin

Inventions 2024, 9(4), 89; https://doi.org/10.3390/inventions9040089 - 13 Aug 2024

Viewed by 870

Abstract

Infusion systems are widely used in clinical medicine. Intravenous infusion therapy must be monitored to ensure patient safety. We proposed a compact flow rate sensor device based on the time-of-flight method. This device included one ceramic heater and two infrared sensors. Practical sensor [...] Read more.

Infusion systems are widely used in clinical medicine. Intravenous infusion therapy must be monitored to ensure patient safety. We proposed a compact flow rate sensor device based on the time-of-flight method. This device included one ceramic heater and two infrared sensors. Practical sensor prototypes were fabricated and characterized. The response time was 30 s. The sensor range was estimated to be 33 dB from μL/min to tens of mL/min, covering almost the entire usage range This flow rate sensor can be applied to common infusion tubes. Through the use of a mobile phone app, detailed information can be presented in real time. Full article

(This article belongs to the Section Inventions and Innovation in Design, Modeling and Computing Methods)

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17 pages, 2071 KiB

Open AccessArticle

A Novel Technique for the Optimization of Energy Cost Management and Operation of Microgrids Inspired from the Behavior of Egyptian Stray Dogs

by Hatem Y. Diab and Mahmoud Abdelsalam

Inventions 2024, 9(4), 88; https://doi.org/10.3390/inventions9040088 - 30 Jul 2024

Viewed by 1116

Abstract

Managing costs in microgrids presents a formidable challenge due to the intricate blend of renewable and non-renewable energy sources that underpin their power generation. Ensuring seamless integration of microgrids with the national grid is pivotal for continuous load demand satisfaction and adherence to [...] Read more.

Managing costs in microgrids presents a formidable challenge due to the intricate blend of renewable and non-renewable energy sources that underpin their power generation. Ensuring seamless integration of microgrids with the national grid is pivotal for continuous load demand satisfaction and adherence to liberalized energy market mandates. To address this challenge, this paper introduces a new optimization technique for the Cost Management and Operation System (CMOS) of multi-source microgrids through a smart management unit. The cornerstone of this unit is the Egyptian Stray Dog Optimization (ESDO) algorithm, meticulously designed to optimize operational costs in line with load demands, energy cost dynamics, and generation proficiencies. Rigorous testing of the proposed system was conducted on a multi-resource microgrid using MATLAB, encompassing various operational scenarios. The simulation outcomes consistently highlighted the unit’s capability to achieve optimal cost-efficiency. Comparative analysis with other optimization techniques, particularly Particle Swarm Optimization (PSO), demonstrated the superior performance of the Egyptian Stray Dog algorithm, underscoring its potential as a leading solution in this domain. Full article

(This article belongs to the Special Issue Innovative Strategy of Protection and Control for the Grid)

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22 pages, 5758 KiB

Open AccessArticle

Tailoring Laser Powder Bed Fusion Process Parameters for Standard and Off-Size Ti6Al4V Metal Powders: A Machine Learning Approach Enhanced by Photodiode-Based Melt Pool Monitoring

by Farima Liravi, Sebastian Soo, Sahar Toorandaz, Katayoon Taherkhani, Mahdi Habibnejad-Korayem and Ehsan Toyserkani

Inventions 2024, 9(4), 87; https://doi.org/10.3390/inventions9040087 - 30 Jul 2024

Viewed by 1604

Abstract

An integral part of laser powder bed fusion (LPBF) quality control is identifying optimal process parameters tailored to each application, often achieved through time-consuming and costly experiments. Melt pool dynamics further complicate LPBF quality control due to their influence on product quality. Using [...] Read more.

An integral part of laser powder bed fusion (LPBF) quality control is identifying optimal process parameters tailored to each application, often achieved through time-consuming and costly experiments. Melt pool dynamics further complicate LPBF quality control due to their influence on product quality. Using machine learning and melt pool monitoring data collected with photodiode sensors, the goal of this research was to efficiently customize LPBF process parameters. A novel aspect of this study is the application of standard and off-size powder feedstocks. Ti6Al4V (Ti64) powder was used in three size ranges of 15–53 µm, 15–106 µm, and 45–106 µm to print the samples. This facilitated the development of a process parameters tailoring system capable of handling variations in powder size ranges. Ultimately, per each part, the associated set of light intensity statistical signatures along with the powder size range and the parts’ density, surface roughness, and hardness were used as inputs for three regressors of Feed-Forward Neural Network (FFN), Random Forest (RF), and Extreme Gradient Boosting (XGBoost). The laser power, laser velocity, hatch distance, and energy density of the parts were predicted by the regressors. According to the results obtained on unseen samples, RF demonstrated the best performance in the prediction of process parameters. Full article

(This article belongs to the Special Issue Revolutionizing Manufacturing: Advances in Additive Manufacturing Technologies)

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48 pages, 25750 KiB

Open AccessReview

Review on Research Progress of Pulsating Heat Pipes

by Shiqiang Fang, Chong Zhou, Ye Zhu, Zhong Qian and Cheng Wang

Inventions 2024, 9(4), 86; https://doi.org/10.3390/inventions9040086 - 30 Jul 2024

Viewed by 1605

Abstract

Since their invention by Akachi in 1990s, pulsating heat pipes (PHPs) have attracted widespread interest and application in practice, e.g., grinding, chip cooling, the thermal management of batteries, etc., owing to their notable efficiency in heat transfer and their simplicity and flexibility in [...] Read more.

Since their invention by Akachi in 1990s, pulsating heat pipes (PHPs) have attracted widespread interest and application in practice, e.g., grinding, chip cooling, the thermal management of batteries, etc., owing to their notable efficiency in heat transfer and their simplicity and flexibility in structure. Key factors influencing the heat transfer efficacy of pulsating heat pipes are mainly attributed to the thermophysical properties of the working fluid, the structural parameters, and the operating conditions. Research on pulsating heat pipes is conducted through theoretical investigations, numerical simulations, and visual experiments. In this paper, the research on PHPs in recent decades is reviewed with the consideration of the heat transfer performance mechanism and application of pulsating heat pipes, especially research under operation conditions such as with “status with motion” and with “inconsistent heat flux”. Full article

(This article belongs to the Special Issue Innovations in Heat Exchangers)

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23 pages, 11187 KiB

Open AccessArticle

PI3SO: A Spectroscopic γ-Ray Scanner Table for Sort and Segregate Radwaste Analysis

by Gaetano Elio Poma, Chiara Rita Failla, Simone Amaducci, Luigi Cosentino, Fabio Longhitano, Gianfranco Vecchio and Paolo Finocchiaro

Inventions 2024, 9(4), 85; https://doi.org/10.3390/inventions9040085 - 26 Jul 2024

Cited by 1 | Viewed by 1036

Abstract

The current scenario of radioactive waste management requires innovative and automated solutions to ensure its effectiveness and safety. In response to this need, the Proximity Imaging System for Sort and Segregate Operations (PI3SO) project was proposed. It is a gamma radiation proximity scanner [...] Read more.

The current scenario of radioactive waste management requires innovative and automated solutions to ensure its effectiveness and safety. In response to this need, the Proximity Imaging System for Sort and Segregate Operations (PI3SO) project was proposed. It is a gamma radiation proximity scanner system for radioactive waste with the primary goal of speeding up some aspects of the waste management cycle while reducing direct human operations. The system will provide proximity imaging for hot-spot finding and spectral analysis for radiological characterization, enabling semiautomatic recognition, sorting and separation of radioactive waste. The core of the proposed scanning system consists of an array of 128 CsI(Tl) scintillators, 1 cm³ size, coupled with silicon photomultipliers (SiPMs), installed on a motorized bridge sliding along a suitable table in order to scan the materials under investigation. Full article

(This article belongs to the Section Inventions and Innovation in Applied Chemistry and Physics)

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23 pages, 3215 KiB

Open AccessReview

Aircraft Innovation Trends Enabling Advanced Air Mobility

by Raj Bridgelall

Inventions 2024, 9(4), 84; https://doi.org/10.3390/inventions9040084 - 26 Jul 2024

Viewed by 2033

Abstract

This study presents a comprehensive exploration of vertical take-off and landing (VTOL) aircraft within advanced air mobility (AAM), examining the crucial challenges of integrating these innovative technologies into transportation systems. AAM promises transformational social change by enhancing transportation energy efficiency, safety, and operational [...] Read more.

This study presents a comprehensive exploration of vertical take-off and landing (VTOL) aircraft within advanced air mobility (AAM), examining the crucial challenges of integrating these innovative technologies into transportation systems. AAM promises transformational social change by enhancing transportation energy efficiency, safety, and operational effectiveness. This research utilizes a methodical approach that juxtaposes a systematic review of patents with an extensive analysis of the academic literature to map the innovation landscape of VTOL technology. This dual analysis reveals a dynamic progression in VTOL advancements, highlighting significant strides in aerodynamic optimization, propulsion technology, and control systems. The novelty of this study lies in its dual-method approach, combining patent analysis with the academic literature to provide a holistic view of VTOL technological evolution. The patent analysis reveals that companies have been most productive on innovations relating to VTOL aircraft transition efficiency, control enhancement, and energy management. The literature review identifies key trends such as the rise in electric propulsion technologies and the integration of AI-driven control mechanisms. These results provide new engineering knowledge that can guide future VTOL development and policy formulation. The original contributions include a detailed mapping of VTOL innovation trends, identification of key technological advancements, and a predictive lens into future directions. These findings offer a valuable resource for aerospace engineers, policymakers, and urban planners. This study contributes a detailed assessment of both theoretical foundations and practical applications, fostering a holistic view of the challenges and innovations shaping the future of AAM. By connecting research and practical development, this study serves as a critical tool for strategic decision making and policy formulation towards advancing the integration of VTOL aircraft into sustainable urban transportation networks. Full article

(This article belongs to the Special Issue Advanced Technologies and Artificial Intelligence for Sustainable and Intelligent Transportation Systems)

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12 pages, 2608 KiB

Open AccessArticle

The Effect of Individual Hydrocarbons in the Composition of Diesel Fuel on the Effectiveness of Depressant Additives

by Yana Morozova, Ilya Bogdanov, Andrey Altynov, Alina Titaeva and Maria Kirgina

Inventions 2024, 9(4), 83; https://doi.org/10.3390/inventions9040083 - 24 Jul 2024

Viewed by 1136

Abstract

The use of depressant additives is the most effective and cost-effective way to improve the low-temperature properties of diesel fuels, like the cloud point, cold filter plugging point and pour point. However, the effectiveness of depressant additives depends on the composition of the [...] Read more.

The use of depressant additives is the most effective and cost-effective way to improve the low-temperature properties of diesel fuels, like the cloud point, cold filter plugging point and pour point. However, the effectiveness of depressant additives depends on the composition of the diesel fuel and the content of certain groups of hydrocarbons in it. In this work, the effect of adding individual hydrocarbons of various groups and structures on the effectiveness of depressant additives is studied. This study is carried out on model aromatic (toluene, tetralin) and n-paraffin hydrocarbons (cetane, heptadecane, heneicosane, docosane) in various concentrations. It is shown that the most negative effect on the depressant additives’ effectiveness is due to the content of the most polar aromatic hydrocarbons and light n-paraffins in the composition of diesel fuel, and the most positive effect is exerted by the content of heavy n-paraffins in small quantities. It is proposed to involve small concentrations (1–3% vol.) of heavy n-paraffin hydrocarbons (heneicosane, docosane) to increase the effectiveness of the depressant additive. It has been established that for the more effective action of the depressant, it is necessary to take into account the content and structure of individual hydrocarbons in the diesel fuel’s composition. Full article

(This article belongs to the Section Inventions and Innovation in Applied Chemistry and Physics)

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33 pages, 4010 KiB

Open AccessReview

A Review of Available Solutions for Implementation of Small–Medium Combined Heat and Power (CHP) Systems

by Cătălina Dobre, Mihnea Costin and Mihaela Constantin

Inventions 2024, 9(4), 82; https://doi.org/10.3390/inventions9040082 - 19 Jul 2024

Cited by 2 | Viewed by 1832

Abstract

The transition towards a sustainable and renewable energy future is essential to mitigate climate change and reduce greenhouse gas emissions. Small–medium combined heat and power (CHP) systems are increasingly popular for distributed energy generation, as they offer improved energy efficiency and reduced emissions [...] Read more.

The transition towards a sustainable and renewable energy future is essential to mitigate climate change and reduce greenhouse gas emissions. Small–medium combined heat and power (CHP) systems are increasingly popular for distributed energy generation, as they offer improved energy efficiency and reduced emissions compared to traditional power generation systems. This article reviews recent research articles related to small–medium CHP systems, including their role in renewable energy systems, use of biofuels, steam injection, diagnostics, and carbon capture. Throughout the research, the high potential of coastal regions has been observed and studied as a solid base for the later development of CHP systems. Based on the reviewed literature, the highest potential solutions are proposed to be further investigated as an efficient, economical solution for generating electricity and heat for various small-scale applications. Full article

(This article belongs to the Topic Marine Renewable Energy, 2nd Edition)

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13 pages, 1125 KiB

Open AccessArticle

Contracted Capacity Optimization Problem of Industrial Customers with Risk Assessment

by Shih-Hsin Tai, Ming-Tang Tsai, Wen-Hsien Huang and Yon-Hon Tsai

Inventions 2024, 9(4), 81; https://doi.org/10.3390/inventions9040081 - 16 Jul 2024

Viewed by 1080

Abstract

This study developed a risk assessment tool for contract capacity optimization problems using the ant colony optimization and auto-regression model. Based on the historical data of demand consumption, the Least Square algorithm, the Recursive Levinson–Durbin algorithm, and the Burg algorithm were used to [...] Read more.

This study developed a risk assessment tool for contract capacity optimization problems using the ant colony optimization and auto-regression model. Based on the historical data of demand consumption, the Least Square algorithm, the Recursive Levinson–Durbin algorithm, and the Burg algorithm were used to derive the auto-regression model. Then, ant colony optimization was used to search for the auto-regression model’s best p-order parameters. To avoid the risk of setting the contract capacity, this paper designed the risk tolerance parameter β to correct the predicted value of the auto-regression model. Ant colony optimization was also used to search for the optimal contract capacity with risk assessment under the two-stage time-of-use and three-stage time-of-use. This study employed an industrial consumer with high voltage power in Taiwan as the research object, used the AR model to estimate the contract capacity under the risk assessment, and cut back electricity usage to reduce the operation cost. The results can be used as a basis to develop an efficient tool for industrial customers to select contract capacities with risks to obtain the best economic benefits. Full article

(This article belongs to the Section Inventions and Innovation in Design, Modeling and Computing Methods)

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18 pages, 9010 KiB

Open AccessArticle

Real-Time Precision in 3D Concrete Printing: Controlling Layer Morphology via Machine Vision and Learning Algorithms

by João M. Silva, Gabriel Wagner, Rafael Silva, António Morais, João Ribeiro, Sacha Mould, Bruno Figueiredo, João M. Nóbrega and Paulo J. S. Cruz

Inventions 2024, 9(4), 80; https://doi.org/10.3390/inventions9040080 - 16 Jul 2024

Viewed by 1679

Abstract

3D concrete printing (3DCP) requires precise adjustments to parameters to ensure accurate and high-quality prints. However, despite technological advancements, manual intervention still plays a prominent role in this process, leading to errors and inconsistencies in the final printed part. To address this issue, [...] Read more.

3D concrete printing (3DCP) requires precise adjustments to parameters to ensure accurate and high-quality prints. However, despite technological advancements, manual intervention still plays a prominent role in this process, leading to errors and inconsistencies in the final printed part. To address this issue, machine learning vision models have been developed and utilized to analyze captured images and videos of the printing process, detecting defects and deviations. The data collected enable automatic adjustments to print settings, improving quality without the need for human intervention. This work first examines various techniques for real-time and offline corrections. It then introduces a specialized computer vision setup designed for real-time control in robotic 3DCP. Our main focus is on a specific aspect of machine learning (ML) within this system, called speed control, which regulates layer width by adjusting the robot motion speed or material flow rate. The proposed framework consists of three main elements: (1) a data acquisition and processing pipeline for extracting printing parameters and constructing a synthetic training dataset, (2) a real-time ML model for parameter optimization, and (3) a depth camera installed on a customized 3D-printed rotary mechanism for close-range monitoring of the printed layer. Full article

(This article belongs to the Special Issue Innovations in 3D Printing 3.0)

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13 pages, 1283 KiB

Open AccessArticle

Increasing the Reliability of Software Systems Using a Large-Language-Model-Based Solution for Onboarding

by Ioan Cristian Schuszter and Marius Cioca

Inventions 2024, 9(4), 79; https://doi.org/10.3390/inventions9040079 - 15 Jul 2024

Viewed by 1241

Abstract

Software systems are often maintained by a group of experienced software developers in order to ensure that faults that may bring the system down are less likely. Large turnover in organizations such as CERN makes it important to think of ways of onboarding [...] Read more.

Software systems are often maintained by a group of experienced software developers in order to ensure that faults that may bring the system down are less likely. Large turnover in organizations such as CERN makes it important to think of ways of onboarding newcomers on a technical project rapidly. This paper focuses on optimizing the way that people get up-to-speed on the business logic and technologies used on the project by using a knowledge-imbued large language model that is enhanced using domain-specific knowledge from the group or team’s internal documentation. The novelty of this approach is the gathering of all of these different open-source methods for developing a chatbot and using it in an industrial use-case. Full article

(This article belongs to the Topic Advanced Systems Engineering: Theory and Applications, 2nd Volume)

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13 pages, 2092 KiB

Open AccessArticle

Multi-Parameter Complex Control of Metal Coatings on Ball Plugs of Pipeline Shut-Off Valves

by Varvara Alekhnovich, Vladimir Syasko and Alexander Umanskii

Inventions 2024, 9(4), 78; https://doi.org/10.3390/inventions9040078 - 15 Jul 2024

Cited by 2 | Viewed by 1276

Abstract

The greatest losses during gas transportation occur in the elements of shut-off valves, the operating parameters of which, among other things, depend on the thickness and hardness of the protective coating of the ball plugs. The study of the parameters of nickel–phosphorus and [...] Read more.

The greatest losses during gas transportation occur in the elements of shut-off valves, the operating parameters of which, among other things, depend on the thickness and hardness of the protective coating of the ball plugs. The study of the parameters of nickel–phosphorus and chrome coatings on ball plugs of serially produced shut-off valves, including control of their thickness and hardness, was carried out. Based on the test results, deviations in the actual parameters of coatings from the requirements of technological documentation were revealed, the necessity of their complex control was substantiated, recommendations on the choice of methods and equipment were formulated, and the main provisions of the test methodology were developed. Full article

(This article belongs to the Section Inventions and Innovation in Biotechnology and Materials)

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38 pages, 14701 KiB

Open AccessReview

The Future of Septic Tanks: Uncovering Technological Trends through Patent Analysis

by Raihani Rafie, Azamuddin Hardy, Nuraina Mohamad Zain, Stefan Gödeke and Pg Emeroylariffion Abas

Inventions 2024, 9(4), 77; https://doi.org/10.3390/inventions9040077 - 14 Jul 2024

Viewed by 1344

Abstract

As global urbanisation, industrialisation, and population growth escalate, the production of wastewater also increases, leading to significant water pollution on a global scale. This pollution poses severe threats to environmental health, wildlife, and human communities. In rural areas where centralised sewage systems are [...] Read more.

As global urbanisation, industrialisation, and population growth escalate, the production of wastewater also increases, leading to significant water pollution on a global scale. This pollution poses severe threats to environmental health, wildlife, and human communities. In rural areas where centralised sewage systems are often absent, septic tanks play a crucial role in managing wastewater. They separate solids from liquids and facilitate the biological decomposition of organic matter. This paper utilises a Patent Landscape Review (PLR) to analyse the scope and direction of innovations in septic tank technology. Conducted on 23 September 2022, the patent search targeted filings from January 2001 through June 2022 to identify prevailing trends and advancements within this field. Through a detailed examination of 889 patents, categorised by keywords, processes, materials, and designs, this study offers a comprehensive overview of the patent landscape for septic tanks. Key findings indicate that fibreglass cylindrical tanks dominate the market due to their durability and efficiency. This review also highlights a growing trend towards modular septic systems, which offer scalable solutions adaptable to specific environmental conditions. Furthermore, some patents propose the repurposing of various objects as septic tanks, demonstrating a move towards sustainability by reducing waste and enhancing environmental conservation. This paper emphasises the importance of continued innovation in septic tank technology to address the challenges of effective wastewater management in underserved rural communities. Full article

(This article belongs to the Section Inventions and Innovation in Biotechnology and Materials)

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10 pages, 1294 KiB

Open AccessArticle

Mathematical Modeling of Oxygen Transfer Using a Bubble Generator at a High Reynolds Number: A Partial Differential Equation Approach for Air-to-Water Transfer

by Mihaela Constantin, Cătălina Dobre and Mugurel Oprea

Inventions 2024, 9(4), 76; https://doi.org/10.3390/inventions9040076 - 12 Jul 2024

Viewed by 848

Abstract

This paper presents the mathematical modeling of the oxygen transfer process using partial differential equations (PDEs). This process is crucial in various environmental and engineering applications, such as wastewater treatment, aeration systems, and natural water bodies, in order to maintain water quality. The [...] Read more.

This paper presents the mathematical modeling of the oxygen transfer process using partial differential equations (PDEs). This process is crucial in various environmental and engineering applications, such as wastewater treatment, aeration systems, and natural water bodies, in order to maintain water quality. The authors solved the typical PDE for describing the change in oxygen concentration over time and present the developed model of the differential equation with the term “source”, indicating that the model could be used to optimize oxygen transfer in various environmental and engineering applications, contributing to improved water quality and system efficiency. Full article

(This article belongs to the Section Inventions and Innovation in Design, Modeling and Computing Methods)

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21 pages, 4216 KiB

Open AccessArticle

Comparative Economic Analysis of Transmission Lines Adopted for Energy-Saving Conductors Considering Life Cycle Cost

by Lanxin Fan, Heng Chen, Shuyuan Zhao and Yinan Wang

Inventions 2024, 9(4), 75; https://doi.org/10.3390/inventions9040075 - 12 Jul 2024

Viewed by 1264

Abstract

Transmission lines serve as pivotal equipment within the power system. Conductors, the primary medium for power transmission and distribution, directly influence the construction cost, operational performance, and long-term benefits of transmission line projects. This study first provides a detailed introduction to the life [...] Read more.

Transmission lines serve as pivotal equipment within the power system. Conductors, the primary medium for power transmission and distribution, directly influence the construction cost, operational performance, and long-term benefits of transmission line projects. This study first provides a detailed introduction to the life cycle cost of transmission lines. It utilizes linear regression analysis, the grey model, and the autoregressive integrated moving average model to forecast the electricity sales benefit and quantify the carbon reduction benefits of energy-saving conductors through a methodology. Through the life cycle cost model, we found that operating costs, particularly energy loss costs, dominate the total expenses, accounting for 65% to 66.2%. The JLHA3-425 scheme offers the lowest life cycle cost of 22,891.66 k$. Comparing economic indicators like ENPV, EIRR, and DPP confirmed that the JLHA3-425 medium-strength aluminum alloy stranded wire emerged as the most economically viable option among the evaluated schemes, holding substantial promise for fostering economic and environmental sustainability in electrical power transmission. Full article

(This article belongs to the Special Issue Recent Advances and Challenges in Emerging Power Systems: 2nd Edition)

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18 pages, 4943 KiB

Open AccessArticle

Analysis of a Newly Developed Afterburner System Employing Hydrogen–Methane Blends

by Florin Gabriel Florean, Andreea Mangra, Marius Enache, Razvan Carlanescu, Alexandra Taranu and Madalina Botu

Inventions 2024, 9(4), 74; https://doi.org/10.3390/inventions9040074 - 11 Jul 2024

Viewed by 786

Abstract

A considerable number of Combined Heat and Power (CHP) systems continue to depend on fossil fuels like oil and natural gas, contributing to significant environmental pollution and the release of greenhouse gases. Two V-gutter flame holder prototypes (P1 and P2) with the same [...] Read more.

A considerable number of Combined Heat and Power (CHP) systems continue to depend on fossil fuels like oil and natural gas, contributing to significant environmental pollution and the release of greenhouse gases. Two V-gutter flame holder prototypes (P1 and P2) with the same expansion angle, fueled with pure hydrogen (100% H₂) or hydrogen–methane mixtures (60% H₂ + 40% CH₄, 80% H₂ + 20% CH₄), intended for use in cogeneration applications, have been designed, manufactured, and tested. Throughout the tests, the concentrations of CO₂, CO, and NO in the flue gas were monitored, and particle image velocimetry (PIV) measurements were performed. The CO, CO₂, respectively, and NO emissions gradually decreased as the percentage of H₂ in the fuel mixture increased. The NO emissions were significantly lower in the case of prototype P2 in comparison with prototype P1 in all measurement points for all used fuel mixtures. The shortest recirculation zone was observed for P1, where the axial velocity reaches a negative peak of approximately 12 m/s at roughly 50 mm downstream of the edge of the flame holder, and the recirculation region spans about 90 mm. In comparison, the P2 prototype has a length of the recirculation region span of about 100 mm with a negative peak of approximately 14 m/s. The data reveal high gradients in flow velocity near the flow separation point, which gradually smooth out with increasing downstream distance. Despite their similar design, P2 consistently performs better across all measured velocity components. This improvement can be attributed to the larger fuel injection holes, which enhance fuel–air mixing and combustion stability. Additionally, the presence of side walls directing the flow around the flame stabilizer further aids in maintaining a stable combustion process. Full article

(This article belongs to the Special Issue Thermodynamic and Technical Analysis for Sustainability (Volume 3))

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26 pages, 2408 KiB

Open AccessArticle

Approximate Closed-Form Solution of the Differential Equation Describing Droplet Flight during Sprinkler Irrigation

by Dario Friso

Inventions 2024, 9(4), 73; https://doi.org/10.3390/inventions9040073 - 10 Jul 2024

Viewed by 700

Abstract

Sprinkler irrigation is widely used in agriculture because it allows for rational use of water. However, it can induce negative effects of soil erosion and of surface waterproofing. The scholars of these phenomena use the numerical integration of the equation of motion, but [...] Read more.

Sprinkler irrigation is widely used in agriculture because it allows for rational use of water. However, it can induce negative effects of soil erosion and of surface waterproofing. The scholars of these phenomena use the numerical integration of the equation of motion, but if there was an analytical solution, the study would be facilitated, and this solution could be used as software for regulating sprinklers. Therefore, in this study, the solution of the differential equation of the flight of droplets produced by sprinklers in the absence of wind was developed. The impossibility of an exact analytical solution to the ballistic problem due to the variability of the drag coefficient of the droplets is known; therefore, to find the integrals in closed form, the following were adopted: a new formula for the drag coefficient; a projection of the dynamic’s equation onto two local axes, one tangent and one normal to the trajectory and some linearization. To reduce the errors caused by the latter, the linearization coefficients and their calculation formulas were introduced through multiple non-linear regressions with respect to the jet angle and the initial droplet speed. The analytical modeling obtained, valid for jet angles from 10° to 40°, was compared to the exact numerical solution, showing, for the total travel distance, a high accuracy with a mean relative error MRE of 1.8% ± 1.4%. Even the comparison with the experimental data showed high accuracy with an MRE of 2.5% ±1.1%. These results make the analytical modeling capable of reliably calculating the travel distance, the flight time, the maximum trajectory height, the final fall angle and the ground impact speed. Since the proposed analytical modeling uses only elementary functions, it can be implemented in PLC programmable logic controllers, which could be useful for controlling water waste and erosive effects on the soil during sprinkler irrigation. Full article

(This article belongs to the Special Issue New Sights in Fluid Mechanics and Transport Phenomena)

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15 pages, 6067 KiB

Open AccessArticle

TCAD Modelling of Magnetic Hall Effect Sensors

by Vartika Pandey, Vlad Marsic, Petar Igic and Soroush Faramehr

Inventions 2024, 9(4), 72; https://doi.org/10.3390/inventions9040072 - 10 Jul 2024

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Abstract

In this paper, a gallium nitride (GaN) magnetic Hall effect current sensor is simulated in 2D and 3D using the TCAD Sentaurus simulation toolbox. The model takes into account the piezoelectric polarization effect and the Shockley–Read–Hall (SRH) and Fermi–Dirac statistics for all simulations. [...] Read more.

In this paper, a gallium nitride (GaN) magnetic Hall effect current sensor is simulated in 2D and 3D using the TCAD Sentaurus simulation toolbox. The model takes into account the piezoelectric polarization effect and the Shockley–Read–Hall (SRH) and Fermi–Dirac statistics for all simulations. The galvanic transport model of TCAD Sentaurus is used to model the Lorentz force and magnetic behaviour of the sensor. The current difference, total current, and sensitivity simulations are systematically calibrated against experimental data. The sensor is optimised using varying geometrical and biasing parameters for various ambient temperatures. This unintentionally doped ungated current sensor has enhanced sensitivity to 16.5 %

T^{- 1}

when reducing the spacing between the drains to 1 μm and increasing the source to drain spacing to 76 μm. It is demonstrated that the sensitivity degrades at 448 K (S = 12 %T⁻¹), 373 K (S = 14.1 %T⁻¹) compared to 300 K (S = 16.5 %T⁻¹). The simulation results demonstrate a high sensitivity of GaN sensors at elevated temperatures, outperforming silicon counterparts. Full article

(This article belongs to the Special Issue Novel Magnetic Materials and Magnetism in Spintronics)

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28 pages, 4065 KiB

Open AccessArticle

Modeling and Simulation of a 2SPU-RU Parallel Mechanism for a Prosthetic Ankle with Three Degrees of Freedom

by Victoria E. Abarca and Dante A. Elias

Inventions 2024, 9(4), 71; https://doi.org/10.3390/inventions9040071 - 9 Jul 2024

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Abstract

To assist an individual with an amputation in regaining daily quality of life, a 2SPU-RU type parallel mechanism was developed based on ankle biomechanics. The inverse kinematic analysis of this mechanism was performed using the vector method. Subsequently, the Jacobian matrices were analyzed. [...] Read more.

To assist an individual with an amputation in regaining daily quality of life, a 2SPU-RU type parallel mechanism was developed based on ankle biomechanics. The inverse kinematic analysis of this mechanism was performed using the vector method. Subsequently, the Jacobian matrices were analyzed. The dynamic model of the mechanism was then created based on the principle of virtual work, and its theoretical solution was compared with numerical results obtained in a simulation environment. Additionally, the validity of the dynamic model and the inverse kinematics was verified by comparing theoretical and simulation results for the movements of plantarflexion–dorsiflexion, eversion–inversion, and abduction–adduction during the gait cycle. Full article

(This article belongs to the Topic Advanced Systems Engineering: Theory and Applications, 2nd Volume)

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19 pages, 4761 KiB

Open AccessArticle

Adaptive Variable Design Algorithm for Improving Topology Optimization in Additive Manufacturing Guided Design

by Abraham Vadillo Morillas, Jesús Meneses Alonso, Alejandro Bustos Caballero, Cristina Castejón Sisamón and Alessandro Ceruti

Inventions 2024, 9(4), 70; https://doi.org/10.3390/inventions9040070 - 1 Jul 2024

Cited by 1 | Viewed by 1070

Abstract

CAD-CAE software companies have introduced numerous tools aimed at facilitating topology optimization through Finite Element Simulation, thereby enhancing accessibility for designers via user-friendly interfaces. However, the imposition of intricate constraint conditions or additional restrictions during calculations may introduce instability into the resultant outcomes. [...] Read more.

CAD-CAE software companies have introduced numerous tools aimed at facilitating topology optimization through Finite Element Simulation, thereby enhancing accessibility for designers via user-friendly interfaces. However, the imposition of intricate constraint conditions or additional restrictions during calculations may introduce instability into the resultant outcomes. In this paper, an algorithm for updating the design variables called Adaptive Variable Design is proposed to keep the final design space volume of the optimized part consistently under the target value while giving the main algorithm multiple chances to update the optimization parameters and search for a valid design. This algorithm aims to produce results that are more conducive to manufacturability and potentially more straightforward in interpretation. A comparison between several commercial software packages and the proposed algorithm, implemented in MATLAB R2023a, is carried out to prove the robustness of the latter. By simulating identical parts under similar conditions, we seek to generate comparable results and underscore the advantages stemming from the adoption and comprehension of the proposed topology optimization methodology. Our findings reveal that the integrated enhancements within MATLAB pertaining to the topology optimization process yield favourable outcomes with respect to discretization and the manufacturability of the resultant geometries. Furthermore, we assert that the methodology evaluated within MATLAB holds promise for potential integration into commercial packages, thereby enhancing the efficiency of topology optimization processes. Full article

(This article belongs to the Special Issue Innovations in 3D Printing 3.0)

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22 pages, 5609 KiB

Open AccessArticle

Road Anomaly Detection with Unknown Scenes Using DifferNet-Based Automatic Labeling Segmentation

by Phuc Thanh-Thien Nguyen, Toan-Khoa Nguyen, Dai-Dong Nguyen, Shun-Feng Su and Chung-Hsien Kuo

Inventions 2024, 9(4), 69; https://doi.org/10.3390/inventions9040069 - 28 Jun 2024

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Abstract

Obstacle avoidance is essential for the effective operation of autonomous mobile robots, enabling them to detect and navigate around obstacles in their environment. While deep learning provides significant benefits for autonomous navigation, it typically requires large, accurately labeled datasets, making the data’s preparation [...] Read more.

Obstacle avoidance is essential for the effective operation of autonomous mobile robots, enabling them to detect and navigate around obstacles in their environment. While deep learning provides significant benefits for autonomous navigation, it typically requires large, accurately labeled datasets, making the data’s preparation and processing time-consuming and labor-intensive. To address this challenge, this study introduces a transfer learning (TL)-based automatic labeling segmentation (ALS) framework. This framework utilizes a pretrained attention-based network, DifferNet, to efficiently perform semantic segmentation tasks on new, unlabeled datasets. DifferNet leverages prior knowledge from the Cityscapes dataset to identify high-entropy areas as road obstacles by analyzing differences between the input and resynthesized images. The resulting road anomaly map was refined using depth information to produce a robust drivable area and map of road anomalies. Several off-the-shelf RGB-D semantic segmentation neural networks were trained using pseudo-labels generated by the ALS framework, with validation conducted on the GMRPD dataset. Experimental results demonstrated that the proposed ALS framework achieved mean precision, mean recall, and mean intersection over union (IoU) rates of 80.31%, 84.42%, and 71.99%, respectively. The ALS framework, through the use of transfer learning and the DifferNet network, offers an efficient solution for semantic segmentation of new, unlabeled datasets, underscoring its potential for improving obstacle avoidance in autonomous mobile robots. Full article

(This article belongs to the Special Issue Advanced Technologies and Artificial Intelligence for Sustainable and Intelligent Transportation Systems)

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13 pages, 4326 KiB

Open AccessArticle

Design Principles for Laser-Printed Macrofluidics

by Gilad Gome, Ofra Benny, Oded Shoseyov and Jonathan Giron

Inventions 2024, 9(4), 68; https://doi.org/10.3390/inventions9040068 - 26 Jun 2024

Viewed by 1363

Abstract

This paper presents a novel method for fabricating fluidic circuits using laser printing technology. The method allows for rapid prototyping of macrofluidic devices with control over fluid manipulation and environmental conditions. We employed a high-resolution laser cutter to etch fluidic channels into various [...] Read more.

This paper presents a novel method for fabricating fluidic circuits using laser printing technology. The method allows for rapid prototyping of macrofluidic devices with control over fluid manipulation and environmental conditions. We employed a high-resolution laser cutter to etch fluidic channels into various substrates, optimizing parameters such as laser power, speed, and substrate material. Our results demonstrate excellent performance in controlling fluid flow and maintaining environmental conditions, handling a wide range of fluids and flow rates. The devices were tested in multiple settings such as with high school students and in research laboratories in universities. We tested the laser-printed macrofluidcs mechanically for durability. We present previous works in microbiology with plants, microbial, and mammalian cell lines showing reliable operation with minimal leakage and consistent fluid dynamics. The versatility and scalability of this approach make it a promising tool for advancing research and innovation in fluidics, providing a robust platform for growing, manipulating, and experimenting with diverse biological systems from cells to whole organisms. We conclude that laser-printed macrofluidics can significantly contribute to fields such as biomedical research, synthetic biology, tissue engineering, and STEM education. Full article

(This article belongs to the Section Inventions and Innovation in Biotechnology and Materials)

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Inventions, Volume 9, Issue 4 (August 2024) – 24 articles

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