Inventions

19 pages, 5542 KB

Open AccessArticle

Enhanced Frequency Regulation of Islanded Airport Microgrid Using IAE-Assisted Control with Reaction Curve-Based FOPDT Modeling

by Tarun Varshney, Naresh Patnana and Vinay Pratap Singh

Inventions 2025, 10(5), 88; https://doi.org/10.3390/inventions10050088 - 2 Oct 2025

Abstract

This paper investigates frequency regulation of an airport microgrid (AIM) through the application of an integral absolute error (IAE)-assisted control approach. The islanded AIM is initially captured using a linearized transfer function model to accurately reflect its dynamic characteristics. This model is then [...] Read more.

This paper investigates frequency regulation of an airport microgrid (AIM) through the application of an integral absolute error (IAE)-assisted control approach. The islanded AIM is initially captured using a linearized transfer function model to accurately reflect its dynamic characteristics. This model is then simplified using a first-order plus dead time (FOPDT) approximation derived via a reaction-curve-based method, which balances between model simplicity and accuracy. Two different proportional–integral–derivative (PID) controllers are designed to meet distinct objectives: one focuses on set-point tracking (SPT) to maintain the target frequency levels, while the other addresses load disturbance rejection (LDR) to reduce the effects of load fluctuations. A thorough comparison of these controllers demonstrates that the SPT-mode PID controller outperforms the LDR-mode controller by providing an improved transient response and notably lower error measures. The results underscore the effectiveness of combining IAE-based control with reaction curve modeling to tune PID controllers for islanded AIM systems, contributing to enhanced and reliable frequency regulation for microgrid operations. Full article

(This article belongs to the Section Inventions and Innovation in Electrical Engineering/Energy/Communications)

19 pages, 2190 KB

Open AccessArticle

TRIZ-Based Conceptual Enhancement of a Multifunctional Rollator Walker Design Integrating Wheelchair, Pilates Chair, and Stepladder

by Elwin Nesan Selvanesan, Poh Kiat Ng, Kia Wai Liew, Jian Ai Yeow, Chai Hua Tay, Peng Lean Chong and Yu Jin Ng

Inventions 2025, 10(5), 87; https://doi.org/10.3390/inventions10050087 - 28 Sep 2025

Abstract

The development of a multifunctional invention requires several refinements for optimizing each function. This study presents a Theory of Inventive Problem Solving (TRIZ)-based conceptual framework for enhancing an innovative multifunctional assistive technology device that integrates the functionalities of a rollator walker, wheelchair, Pilates [...] Read more.

The development of a multifunctional invention requires several refinements for optimizing each function. This study presents a Theory of Inventive Problem Solving (TRIZ)-based conceptual framework for enhancing an innovative multifunctional assistive technology device that integrates the functionalities of a rollator walker, wheelchair, Pilates chair, and stepladder. The limitations of the multifunctional rollator walker were identified from the user feedback of a foundational work and were then addressed by identifying the engineering and physical contradictions and problem modeling using Su-field analysis. Through TRIZ Inventive Principles, the proposed design eliminates common trade-offs between portability, stability, and usability. The conceptual enhancement incorporates features such as deployable steps, the utilization of high strength–to–weight ratio material, foldability, a passive mechanical brake-locking system, retractable armrests, the incorporation of spring-assist hinges, and the use of large tires with vibration-dampening hubs. This study contributes a novel, user-focused, and space-saving mobility solution that aligns with the evolving demands of assistive technology, laying the groundwork for future iterations involving smart control, power assist, and modular enhancements. Full article

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

► Show Figures

Figure 1

15 pages, 2896 KB

Open AccessArticle

Platinum Atom-Functionalized Carbon Nanotubes as Efficient Sensors for CO and CO₂: A Theoretical Investigation

by Natalia P. Boroznina, Sergey V. Boroznin, Irina V. Zaporotskova, Pavel A. Zaporotskov, Dmitry F. Sergeev, Govindhasamy Murugadoss, Nachimuthu Venkatesh and Shaik Gouse Peera

Inventions 2025, 10(5), 86; https://doi.org/10.3390/inventions10050086 - 26 Sep 2025

Abstract

This study presents a theoretical investigation of platinum-modified single-wall carbon nanotubes (SWCNTs) of types (6.0) and (6.6) for their potential application as gas sensor materials. Quantum chemical calculations using density functional theory (DFT) were performed to evaluate the interaction mechanisms with carbon monoxide [...] Read more.

This study presents a theoretical investigation of platinum-modified single-wall carbon nanotubes (SWCNTs) of types (6.0) and (6.6) for their potential application as gas sensor materials. Quantum chemical calculations using density functional theory (DFT) were performed to evaluate the interaction mechanisms with carbon monoxide (CO) and carbon dioxide (CO₂) molecules. The results revealed that pristine SWCNTs exhibit weak and unstable interactions with CO and CO₂, indicating limited sensing capabilities. However, the modification with platinum atoms significantly enhanced their adsorption properties. The most energetically favorable configuration was found when the platinum atom was located at the center of a C–C bond on the SWCNT surface, ensuring the stability of the metal-functionalized system. The Pt-modified SWCNTs exhibited stable sorption interactions with CO and CO₂, characterized by weak van der Waals forces, enabling the reusability of the sensor without contamination. Additionally, the adsorption of these gas molecules induced changes in the band gap of the nanocomposite system, indicating a variation in conductivity upon gas exposure. The distinct band gap changes for the CO and CO₂ adsorption suggest the selectivity of the sensor towards each gas. Overall, the results demonstrate that platinum modification effectively enhances the sensing performance of SWCNTs, paving the way for the development of highly sensitive and selective nanosensors for CO and CO₂ detection based on changes in electronic properties upon gas adsorption. Full article

(This article belongs to the Special Issue Innovative Approaches for Fabricating Membrane Electrode Assemblies for Fuel Cells and Water Electrolysis Applicaions)

► Show Figures

Figure 1

32 pages, 8667 KB

Open AccessArticle

Addressing Development Challenges of the Emerging REEFS Wave Energy Converter

by José P. P. G. Lopes de Almeida and Vinícius G. Machado

Inventions 2025, 10(5), 85; https://doi.org/10.3390/inventions10050085 - 26 Sep 2025

Abstract

This article addresses the multifaceted challenges inherent in the development of the novel REEFS (Renewable Electric Energy From Sea) wave energy converter (WEC). Building on the submerged pressure differential principle, it frames similar WECs before focusing on REEFS that combines renewable energy generation [...] Read more.

This article addresses the multifaceted challenges inherent in the development of the novel REEFS (Renewable Electric Energy From Sea) wave energy converter (WEC). Building on the submerged pressure differential principle, it frames similar WECs before focusing on REEFS that combines renewable energy generation with coastal protection, functioning as an artificial reef. The review follows chronological criteria, encompassing experimental proof-of-concept, small-scale laboratory modeling, simplified and advanced computational fluid dynamics (CFD) simulations, and the design of a forthcoming real-sea model deployment. Key milestones include the validation of a passive variable porosity system, demonstration of wave-to-wire energy conversion, and quantification of wave attenuation for coastal defense. Additionally, the study introduces a second patent-protected REEFS configuration, isolating internal components from seawater via an elastic enveloping membrane. Challenges related to scaling, numerical modeling, and funding are thoroughly examined. The results highlight the importance of the proof-of-concept as the keystone of the development process, underscore the relevance of mixed laboratory-computational approaches and emphasize the need for a balanced equilibrium between intellectual property safeguard and scientific publishing. The REEFS development trajectory offers interesting insights for researchers and developers navigating the complex innovation seas of emerging wave energy technologies. Full article

(This article belongs to the Section Inventions and Innovation in Energy and Thermal/Fluidic Science)

14 pages, 3250 KB

Open AccessArticle

An IoT-Enabled System for Monitoring and Predicting Physicochemical Parameters in Rosé Wine Storage Process

by Xu Zhang, Jihong Yang, Ruijie Zhao, Ziquan Qin and Zhuojun Xie

Inventions 2025, 10(5), 84; https://doi.org/10.3390/inventions10050084 - 24 Sep 2025

Abstract

The evolution of the winemaking industry towards intelligent and digitalized systems is crucial for precision winemaking and ensuring product safety. In this context, the Internet of Things (IoT) provides a key strategy for real-time monitoring and data management throughout the winemaking process. However, [...] Read more.

The evolution of the winemaking industry towards intelligent and digitalized systems is crucial for precision winemaking and ensuring product safety. In this context, the Internet of Things (IoT) provides a key strategy for real-time monitoring and data management throughout the winemaking process. However, comprehensive multi-parameter IoT-based monitoring and time-series prediction of physicochemical parameters during storage are currently lacking, limiting the ability to assess storage conditions and provide early warning of quality deterioration. To address these gaps, a multi-parameter IoT monitoring system was designed and developed to track conductivity, dissolved oxygen, and temperature in real time. Data were transmitted via a 4th-generation (4G) mobile communication module to the TLINK cloud platform for storage and visualization. An 80-day storage experiment confirmed the system’s reliability for long-term monitoring, and analysis of parameter trends demonstrated its effectiveness in assessing storage conditions and wine quality evolution. Furthermore, Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), Temporal Convolutional Network (TCN) models, and Autoregressive Integrated Moving Average (ARIMA) were implemented to predict physicochemical parameter trends. The TCN model achieved the highest predictive performance, with coefficients of determination (R²) of 0.955, 0.968, and 0.971 for conductivity, dissolved oxygen, and temperature, respectively, while LSTM and GRU showed comparable results. These results demonstrate that integrating IoT-based multi-parameter monitoring with deep learning time-series prediction enables real-time detection of abnormal storage and quality deterioration, providing a novel and practical framework for early warning throughout the wine storage process. Full article

(This article belongs to the Special Issue Inventions and Innovation in Smart Sensing Technologies for Agriculture)

► Show Figures

Figure 1

19 pages, 5120 KB

Open AccessArticle

Paving Integrated Photovoltaic Technology: Numerical Investigation of Fatigue Performance and Design Strategy

by Peichen Cai, Yutong Chai, Susan Tighe, Meng Wang and Shunde Yin

Inventions 2025, 10(5), 83; https://doi.org/10.3390/inventions10050083 - 24 Sep 2025

Abstract

To elucidate the fatigue damage evolution of solar road panels under long-term loading and enhance their structural durability, this study develops a particle-based discrete element model and simulates fatigue responses under different structural configurations and loading rates. A strength degradation index was established [...] Read more.

To elucidate the fatigue damage evolution of solar road panels under long-term loading and enhance their structural durability, this study develops a particle-based discrete element model and simulates fatigue responses under different structural configurations and loading rates. A strength degradation index was established by introducing peak stress and terminal stress, enabling quantitative evaluation of strength deterioration. Combined with fracture evolution, the dominant mesoscopic damage mechanisms were revealed. The results indicate that structural configuration strongly influences fatigue performance, with square panels showing the best resistance due to geometric symmetry and stable boundary constraints. Loading rate regulates damage evolution: lower rates promote structural coordination but may delay cumulative failure, while higher rates suppress overall deformation yet increase localized fracture risk. Based on these findings, a nonlinear predictive model of the strength degradation rate was constructed (R² = 0.935), offering reliable support for structural life prediction and design optimization. Finally, fatigue-resistant design strategies are proposed, including optimal structural configuration, controlled loading rates, bonding enhancement, and integration of online monitoring—providing both theoretical and technical guidance for high-performance, long-lifespan solar road systems. Full article

(This article belongs to the Section Inventions and Innovation in Electrical Engineering/Energy/Communications)

► Show Figures

Figure 1

20 pages, 3018 KB

Open AccessArticle

Biological Properties of a Composite Polymer Material Based on Polyurea and Submicron-Sized Selenium Particles

by Sergey A. Shumeyko, Dmitriy E. Burmistrov, Denis V. Yanykin, Ilya V. Baimler, Alexandr V. Simakin, Maxim E. Astashev, Mikhail V. Dubinin, Roman Y. Pishchalnikov, Ruslan M. Sarimov, Valeriy A. Kozlov, Alexey S. Dorokhov and Andrey Yu. Izmailov

Inventions 2025, 10(5), 82; https://doi.org/10.3390/inventions10050082 - 19 Sep 2025

Abstract

Using the method of laser ablation in liquid, submicron-sized particles of zero-valent amorphous selenium (Se SMPs) were created. A number of composite polymer materials were manufactured based on polyurea and Se SMPs at concentrations ranging 0.1–2.5 wt.%. The manufactured materials showed no significant [...] Read more.

Using the method of laser ablation in liquid, submicron-sized particles of zero-valent amorphous selenium (Se SMPs) were created. A number of composite polymer materials were manufactured based on polyurea and Se SMPs at concentrations ranging 0.1–2.5 wt.%. The manufactured materials showed no significant surface or internal defects at either the macro or micro level. It was found that the Se SMPs were not uniformly distributed inside the polymer, but formed ordered areas with slightly higher and lower concentrations of the particles. It was demonstrated that the manufactured materials did not generate a significant amount of active oxygen species, which could damage biological objects such as protein molecules and DNA, while also exhibiting pronounced bacteriostatic properties without significantly affecting the growth and reproduction of mammalian cells. Materials containing 0.25 and 1% Se SMPs, when added to soil, improved the morphometric parameters of radish plants (Raphanus sativus var. sativus). These polymer composite materials based on polyurea with the addition of Se SMPs are promising functional materials for agriculture due to their antibacterial activity. Full article

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

► Show Figures

Figure 1

15 pages, 2814 KB

Open AccessArticle

Functionalized Graphene Quantum Dots for Thin-Film Illuminator and Cell Dyeing Applications

by Ruey-Shin Juang, Yi-Ru Li, Chun-Chieh Fu and Chien-Te Hsieh

Inventions 2025, 10(5), 81; https://doi.org/10.3390/inventions10050081 - 3 Sep 2025

Abstract

Graphene quantum dots (GQDs) have emerged as promising nanomaterials due to their unique optical properties, high biocompatibility, and tunable surface functionalities. In this work, GQDs were synthesized via a one-pot hydrothermal method and further functionalized using polyethylene glycol (PEG) of various molecular weights [...] Read more.

Graphene quantum dots (GQDs) have emerged as promising nanomaterials due to their unique optical properties, high biocompatibility, and tunable surface functionalities. In this work, GQDs were synthesized via a one-pot hydrothermal method and further functionalized using polyethylene glycol (PEG) of various molecular weights and sodium hydroxide to tailor their photoluminescence (PL) behavior and enhance their applicability in thin-film illumination and biological staining. PEG-modified GQDs exhibited a pronounced red-shift and intensified fluorescence response due to aggregation-induced emission, with GQD-PEG (molecular weight: 300,000) achieving up to eight-fold enhancement in PL intensity compared to pristine GQDs. The influence of solvent environments on PL behavior was studied, revealing solvent-dependent shifts and emission intensities. Transmission electron microscopy confirmed the formation of core–shell GQD clusters, while Raman spectroscopy suggested improved structural ordering upon modification. The prepared GQD thin films demonstrated robust fluorescence stability under prolonged water immersion, indicating strong adhesion to glass substrates. Furthermore, the modified GQDs effectively labeled E. coli, Gram-positive, and Gram-negative bacteria, with GQD-PEG and GQD-NaOH displaying red and green emissions, respectively, at optimal concentrations. This study highlights the potential of surface-functionalized GQDs as versatile materials for optoelectronic devices and fluorescence-based bioimaging. Full article

(This article belongs to the Section Inventions and Innovation in Surface Science and Nanotechnology)

► Show Figures

Figure 1

15 pages, 2164 KB

Open AccessArticle

Coordinated Optimization of Multiple Reactive Power Sources for Transient Overvoltage Suppression for New Energy Sending-Out System

by Qinglei Zhang, Lei Luo, Xiaoping Wang, Dehai Zhang, Haibo Li, Zongxiang Lu and Ying Qiao

Inventions 2025, 10(5), 80; https://doi.org/10.3390/inventions10050080 - 1 Sep 2025

Abstract

With the implementation of China’s “dual carbon” strategy, the installed capacity of new energy has grown rapidly. Wind power and photovoltaic power have accounted for more than 40%, but the integration of power electronic apparatus into the grid has resulted in the manifestation [...] Read more.

With the implementation of China’s “dual carbon” strategy, the installed capacity of new energy has grown rapidly. Wind power and photovoltaic power have accounted for more than 40%, but the integration of power electronic apparatus into the grid has resulted in the manifestation of a system with “low inertia and weak damping”, which can easily lead to transient overvoltage problems at transmitters when high-voltage direct-current (HVDC) latching faults occur. Although a variety of dynamic reactive power optimization strategies have been proposed in the existing research, most of them are aimed at single equipment, and multi-reactive power source collaborative control schemes are lacking. In this paper, we innovatively establish a transient voltage analysis model for a new energy transmitter, derive the expression of overvoltage amplitude, and propose a method for the construction of a multi-reactive source collaborative optimization model, which can effectively suppress transient overvoltage through capacity and initial output configuration. We provide a new idea for the safe operation of a significant percentage of new energy grids. The case analysis shows that the co-optimization method outlined in this paper is an effective solution to suppress the transient overvoltage triggered by AC faults and has wide application value. Full article

(This article belongs to the Section Inventions and Innovation in Electrical Engineering/Energy/Communications)

► Show Figures

Figure 1

25 pages, 4045 KB

Open AccessArticle

Optimum Sizing of Solar Photovoltaic Panels at Optimum Tilt and Azimuth Angles Using Grey Wolf Optimization Algorithm for Distribution Systems

by Preetham Goli, Srinivasa Rao Gampa, Amarendra Alluri, Balaji Gutta, Kiran Jasthi and Debapriya Das

Inventions 2025, 10(5), 79; https://doi.org/10.3390/inventions10050079 - 30 Aug 2025

Abstract

This paper presents a novel methodology for the optimal sizing of solar photovoltaic (PV) systems in distribution networks by determining the monthly optimum tilt and azimuth angles to maximize solar energy capture. Using one year of solar irradiation data, the Grey Wolf Optimizer [...] Read more.

This paper presents a novel methodology for the optimal sizing of solar photovoltaic (PV) systems in distribution networks by determining the monthly optimum tilt and azimuth angles to maximize solar energy capture. Using one year of solar irradiation data, the Grey Wolf Optimizer (GWO) is employed to optimize the tilt and azimuth angles with the objective of maximizing monthly solar insolation. Unlike existing approaches that assume fixed azimuth angles, the proposed method calculates both tilt and azimuth angles for each month, allowing for a more precise alignment with solar trajectories. The optimized orientation parameters are subsequently utilized to determine the optimal number and placement of PV panels, as well as the optimal location and sizing of shunt capacitor (SC) banks, for the IEEE 69-bus distribution system. This optimization is performed under peak load conditions using the GWO, with the objectives of minimizing active power losses, enhancing voltage profile stability, and maximizing PV system penetration. The long-term impact of this approach is assessed through a 20-year energy and economic savings analysis, demonstrating substantial improvements in energy efficiency and cost-effectiveness. Full article

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

► Show Figures

Figure 1

26 pages, 1692 KB

Open AccessReview

Comparative Assessment and Deployment of Zeolites, MOFs, and Activated Carbons for CO₂ Capture and Geological Sequestration Applications

by Mohamadou Hamadama Mouctar, Mohamed G Hassan, Nuno Bimbo, Syed Zaheer Abbas and Ihab Shigidi

Inventions 2025, 10(5), 78; https://doi.org/10.3390/inventions10050078 - 28 Aug 2025

Abstract

The rising level of atmospheric carbon dioxide (CO₂) is a major driver of climate change, highlighting the need to develop carbon capture and storage (CCS) technologies quickly. This paper offers a comparative review of three main groups of porous adsorbent materials—zeolites, [...] Read more.

The rising level of atmospheric carbon dioxide (CO₂) is a major driver of climate change, highlighting the need to develop carbon capture and storage (CCS) technologies quickly. This paper offers a comparative review of three main groups of porous adsorbent materials—zeolites, metal–organic frameworks (MOFs), and activated carbons—for their roles in CO₂ capture and long-term storage. By examining their structural features, adsorption capacities, moisture stability, and economic viability, the strengths and weaknesses of each material are assessed. Additionally, five different methods for delivering these materials into depleted oil and gas reservoirs are discussed: direct suspension injection, polymer-assisted transport, foam-assisted delivery, encapsulation with controlled release, and preformed particle gels. The potential of hybrid systems, such as MOF–carbon composites and polymer-functionalized materials, is also examined for improved selectivity and durability in underground environments. This research aims to connect materials science with subsurface engineering, helping guide the selection and use of adsorbent materials in real-world CCS applications. The findings support the optimization of CCS deployment and contribute to broader climate change efforts and the goal of achieving net-zero emissions. Key findings include CO₂ adsorption capacities of 3.5–8.0 mmol/g and surface areas up to 7000 m²/g, with MOFs demonstrating the highest uptake and activated carbons offering cost-effective performance. Full article

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

► Show Figures

Figure 1

13 pages, 3334 KB

Open AccessArticle

Open-Access Crystal Plasticity Finite Element Implementation in ANSYS for Dislocation-Induced Nanoindentation in Magnesium

by Syed Taha Khursheed, Moein Imani Foumani, Yunhua Luo and Guo-zhen Zhu

Inventions 2025, 10(5), 77; https://doi.org/10.3390/inventions10050077 - 28 Aug 2025

Abstract

This study focuses on developing and implementing crystal plasticity finite element modeling (CPFEM) codes on the ANSYS platform. The code incorporates a plasticity constitutive law that describes the behaviors of basal, prismatic, and pyramidal slips in magnesium, and is validated against plane-strain compression [...] Read more.

This study focuses on developing and implementing crystal plasticity finite element modeling (CPFEM) codes on the ANSYS platform. The code incorporates a plasticity constitutive law that describes the behaviors of basal, prismatic, and pyramidal slips in magnesium, and is validated against plane-strain compression experiments and simulations using established codes on the ABAQUS CAE platform. The validated CPFEM code is applied to simulate the dislocation-induced nanoindentation response of pure magnesium across different crystallographic orientations, allowing visualization of strain distributions associated with different slips. Consistent with experimental observations, basal slip is identified as the primary active slip, whereas prismatic and pyramidal slips show varying activities with respect to the direction of the indentation. Novelty arises from an ANSYS–native CPFEM implementation that is cross-validated against published ABAQUS simulations and an experiment under a single, consistent constitutive set. This framework enables orientation-resolved mapping of slip system activity and subsurface strain fields under spherical nanoindentation, providing analysis capability seldom available in prior ANSYS–based studies. Full article

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

► Show Figures

Figure 1

16 pages, 3657 KB

Open AccessArticle

Development and Performance Evaluation of a Vision-Based Automated Oyster Size Classification System

by Jonghwan Baek, Seolha Kim, Chang-Hee Lee, Myeongsu Jeong, Jin-Ho Suh and Jaeyoul Lee

Inventions 2025, 10(5), 76; https://doi.org/10.3390/inventions10050076 - 27 Aug 2025

Abstract

This study presents the development and validation of an automated oyster classification system designed to classify oysters by size and place them into trays for freezing. Addressing limitations in conventional manual processing, the proposed system integrates a vision-based recognition algorithm and a delta [...] Read more.

This study presents the development and validation of an automated oyster classification system designed to classify oysters by size and place them into trays for freezing. Addressing limitations in conventional manual processing, the proposed system integrates a vision-based recognition algorithm and a delta robot (parallel robot) equipped with a soft gripper. The vision system identifies oyster size and optimal grasp points using image moment calculations, enhancing the accuracy of classification for irregularly shaped oysters. Experimental tests demonstrated classification and grasping success rates of 99%. A process simulation based on real industrial conditions revealed that seven units of the automated system are required to match the daily output of 7 tons achieved by 60 workers. When compared with a theoretical 100% success rate, the system showed a marginal production loss of 715 oysters and 15 trays. These results confirm the potential of the proposed system to improve consistency, reduce labor dependency, and increase productivity in oyster processing. Future work will focus on gripper design optimization and parameter tuning to further improve system stability and efficiency. Full article

(This article belongs to the Section Inventions and Innovation in Advanced Manufacturing)

► Show Figures

Figure 1

16 pages, 1334 KB

Open AccessArticle

Wire-Based Solid-State Propellant Management System for Small Form-Factor Space Propulsion

by Pavel O. Savelev, Andrei I. Shumeiko and Victor D. Telekh

Inventions 2025, 10(5), 75; https://doi.org/10.3390/inventions10050075 - 26 Aug 2025

Abstract

The development of dynamic missions of small satellites requires the development of efficient, compact, and reliable propulsion systems (PSs). This paper investigates a propellant storage and supply system (PSSS), utilizing alternative solid-state propellants in the form of wire. To establish the background to [...] Read more.

The development of dynamic missions of small satellites requires the development of efficient, compact, and reliable propulsion systems (PSs). This paper investigates a propellant storage and supply system (PSSS), utilizing alternative solid-state propellants in the form of wire. To establish the background to the suggested solutions implemented in the proposed system, two types of comparative analysis were performed. The first one compared different types of propellant management system designs while the second juxtaposes a variety of propellants. It is shown that the solid-state systems for small satellite operations are advantageous, while the selection of propellants should be focused on safe operations and operational requirements. The principle of operation and structural design of the proposed wire-based solid-state propellant management system are discussed, including the assessment of its engineering realization. The strategies to mitigate the potential problems with the system’s operations such as propellant unwanted deposition and corrosive effects are suggested. An example of using the proposed system is provided, which considers a deep space dynamic mission case. The proposed PSSS architecture is dedicated to increasing the energy efficiency, resilience to environmental factors, and suitability for small satellite platforms, including that of the CubeSat format. Full article

(This article belongs to the Topic Innovation and Inventions in Aerospace and UAV Applications)

► Show Figures

Figure 1

19 pages, 437 KB

Open AccessArticle

Research on Generation and Quality Evaluation of Earthquake Emergency Language Service Contingency Plan Based on Chain-of-Thought Prompt Engineering for LLMs

by Wenyan Zhang, Kai Zhang, Ti Li and Wenhua Deng

Inventions 2025, 10(5), 74; https://doi.org/10.3390/inventions10050074 - 26 Aug 2025

Abstract

China frequently experiences natural disasters, making emergency language services a key link in information transmission, cross-lingual communication, and resource coordination during disaster relief. Traditional contingency plans rely on manual experience, which results in low efficiency, limited coverage, and insufficient dynamic adaptability. Large language [...] Read more.

China frequently experiences natural disasters, making emergency language services a key link in information transmission, cross-lingual communication, and resource coordination during disaster relief. Traditional contingency plans rely on manual experience, which results in low efficiency, limited coverage, and insufficient dynamic adaptability. Large language models (LLMs), with their advantages in semantic understanding, multilingual adaptation, and scalability, provide new technical approaches for emergency language services. Our study establishes the country’s first generative evaluation index system for emergency language service contingency plans, covering eight major dimensions. Through an evaluation of 11 mainstream large language models, including Deepseek, we find that these models perform excellently in precise service stratification and resource network stereoscopic coordination but show significant shortcomings in legal/regulatory frameworks and mechanisms for dynamic evolution. It is recommended to construct a more comprehensive emergency language service system by means of targeted data augmentation, multi-model collaboration, and human–machine integration so as to improve cross-linguistic communication efficiency in emergencies and reduce secondary risks caused by information transmission barriers. Full article

(This article belongs to the Special Issue Advances and Innovations in Deep Learning: Unveiling Multidisciplinary Applications and Challenges)

► Show Figures

Figure 1

20 pages, 4011 KB

Open AccessArticle

Throwing Angle Estimation of a Wire Installation Device with Robotic Arm Using a 3D Model of a Spear

by Yuji Kobayashi, Nobuyoshi Takamitsu, Rikuto Suga, Kotaro Miyake and Yogo Takada

Inventions 2025, 10(5), 73; https://doi.org/10.3390/inventions10050073 - 22 Aug 2025

Abstract

In recent years, the deterioration of social infrastructure such as bridges has become a serious issue in many countries around the world. To maintain the functionality of aging bridges over the long term, it is necessary to conduct regular inspections, detect damage at [...] Read more.

In recent years, the deterioration of social infrastructure such as bridges has become a serious issue in many countries around the world. To maintain the functionality of aging bridges over the long term, it is necessary to conduct regular inspections, detect damage at an early stage, and perform timely repairs. However, inspections require significant cost and time, and ensuring the safety of inspectors remains a major challenge. As a result, inspection using robots has attracted increasing attention. This study focuses on a wire-driven bridge inspection robot designed to inspect the underside of bridge girders. To use this robot, wires must be installed in the space beneath the girders. However, it is difficult to install wires over areas such as rivers. To address this problem, we developed a robotic arm capable of throwing a spear attached to a string. In order to throw the spear accurately to the target location, a three-dimensional dynamic model of the spear in flight was constructed, considering the tension of the string. Using this model, we accurately estimated the required throwing conditions and confirmed that the robotic arm could successfully throw the spear to the target location. Full article

(This article belongs to the Section Inventions and Innovation in Advanced Manufacturing)

► Show Figures

Figure 1

31 pages, 946 KB

Open AccessArticle

Performance Analysis of a Floating Seawater Desalination Structure Based on Heat Pipes

by Juan J. Vallejo Tejero, María Martínez Gómez, Francisco J. Muñoz Gutiérrez and Alejandro Rodríguez Gómez

Inventions 2025, 10(4), 72; https://doi.org/10.3390/inventions10040072 - 14 Aug 2025

Abstract

This study presents a comprehensive numerical simulation and thermal performance analysis of a novel modular floating solar still system, featuring integrated heat-pipe vacuum tube collectors, designed for seawater desalination. This innovative system—subject of International Patent Application WO 2023/062261 A1—not only aims to enhance [...] Read more.

This study presents a comprehensive numerical simulation and thermal performance analysis of a novel modular floating solar still system, featuring integrated heat-pipe vacuum tube collectors, designed for seawater desalination. This innovative system—subject of International Patent Application WO 2023/062261 A1—not only aims to enhance efficiency and scalability beyond traditional solar stills, but also addresses the significant environmental challenge of concentrated brine discharge inherent in conventional desalination methods. The study evolved from an initial theoretical model to a rigorous dynamic thermal model, validated using real hourly meteorological data from Málaga, Andalusia, Spain. This modelling approach was developed to quantify heat transfer mechanisms and accurately predict system performance. The refined hourly simulation forecasts an annual freshwater production of approximately 174 L per unit. Notably, a preliminary economic assessment estimates the Cost of Produced Water per Litre (CPL) at 0.7509 EUR/litre, establishing a valuable baseline for future optimisation. These findings underscore the critical importance of dynamic hourly simulations for realistic performance prediction and validate the technical and preliminary economic feasibility of this novel approach. The system’s projected output, modular floating design, and significant environmental advantages position it as a promising and sustainable solution for freshwater production, particularly in coastal regions and sensitive marine ecosystems. This work provides a solid foundation for future experimental validation, cost optimisation, and scalable implementation of renewable energy-driven desalination. Full article

(This article belongs to the Topic Advancements and Challenges in Marine Renewable Energy and Marine Structures)

► Show Figures

Figure 1

36 pages, 9430 KB

Open AccessArticle

Numerical Method for Internal Structure and Surface Evaluation in Coatings

by Tomas Kačinskas and Saulius Baskutis

Inventions 2025, 10(4), 71; https://doi.org/10.3390/inventions10040071 - 13 Aug 2025

Abstract

This study introduces a MATrix LABoratory (MATLAB, version R2024b, update 1 (24.2.0.2740171))-based automated system for the detection and measurement of indication areas in coated surfaces, enhancing the accuracy and efficiency of quality control processes in metal, polymeric and thermoplastic coatings. The developed code [...] Read more.

This study introduces a MATrix LABoratory (MATLAB, version R2024b, update 1 (24.2.0.2740171))-based automated system for the detection and measurement of indication areas in coated surfaces, enhancing the accuracy and efficiency of quality control processes in metal, polymeric and thermoplastic coatings. The developed code identifies various indication characteristics in the image and provides numerical results, assesses the size and quantity of indications and evaluates conformity to ISO standards. A comprehensive testing method, involving non-destructive penetrant testing (PT) and radiographic testing (RT), allowed for an in-depth analysis of surface and internal porosity across different coating methods, including aluminum-, copper-, polytetrafluoroethylene (PTFE)- and polyether ether ketone (PEEK)-based materials. Initial findings had a major impact on indicating a non-homogeneous surface of obtained coatings, manufactured using different technologies and materials. Whereas researchers using non-destructive testing (NDT) methods typically rely on visual inspection and manual counting, the system under study automates this process. Each sample image is loaded into MATLAB and analyzed using the Image Processing Tool, Computer Vision Toolbox, Statistics and Machine Learning Toolbox. The custom code performs essential tasks such as image conversion, filtering, boundary detection, layering operations and calculations. These processes are integral to rendering images with developed indications according to NDT method requirements, providing a detailed visual and numerical representation of the analysis. RT also validated the observations made through surface indication detection, revealing either the absence of hidden defects or, conversely, internal porosity correlating with surface conditions. Matrix and graphical representations were used to facilitate the comparison of test results, highlighting more advanced methods and materials as the superior choice for achieving optimal mechanical and structural integrity. This research contributes to addressing challenges in surface quality assurance, advancing digital transformation in inspection processes and exploring more advanced alternatives to traditional coating technologies and materials. Full article

(This article belongs to the Section Inventions and Innovation in Advanced Manufacturing)

► Show Figures

Figure 1

17 pages, 5141 KB

Open AccessArticle

Optimization of the Photovoltaic Panel Design Towards Durable Solar Roads

by Peichen Cai, Yutong Chai, Susan Tighe, Meng Wang and Shunde Yin

Inventions 2025, 10(4), 70; https://doi.org/10.3390/inventions10040070 - 11 Aug 2025

Cited by 1

Abstract

To improve the mechanical stability and service durability of solar road structures, this study systematically investigates the mechanical response characteristics of photovoltaic panels with different geometric shapes—including triangles, rectangles, squares, regular pentagons, and regular hexagons—under consistent boundary and loading conditions using the discrete [...] Read more.

To improve the mechanical stability and service durability of solar road structures, this study systematically investigates the mechanical response characteristics of photovoltaic panels with different geometric shapes—including triangles, rectangles, squares, regular pentagons, and regular hexagons—under consistent boundary and loading conditions using the discrete element method (DEM). All panels have a uniform thickness of 10 cm and equivalent surface areas to ensure shape comparability. Side lengths vary among the shapes: square panels with sides of 0.707 m, 1.0 m, and 1.5 m; triangle 1.155 m; rectangle (aspect ratio 1:2) 0.707 m; pentagon 1.175 m; and hexagon 0.577 m. Results show that panel geometry significantly influences stress distribution and deformation behavior. Although triangular panels exhibit higher ultimate bearing capacity and failure energy, they suffer from severe stress concentration and low stiffness. Regular hexagonal panels, due to their geometric symmetry, enable more uniform stress and displacement distributions, offering better stability and crack resistance. Size effect analysis reveals that larger panels improve load-bearing and energy dissipation capacity but exacerbate edge stress concentration and reduce overall stiffness, leading to more pronounced “thinning” deformation and premature failure. Failure mode analysis further indicates that shape governs crack initiation and path, while size determines crack propagation rate and failure extent—revealing a coupled shape–size mechanical mechanism. Regarding assembly, honeycomb arrangements demonstrate superior mechanical performance due to higher compactness and better load-sharing characteristics. The study ultimately recommends the use of small-sized regular hexagonal units and optimized splicing structures to balance strength, stiffness, and durability. These findings provide theoretical guidance and parameter references for the structural design of solar roads. Full article

(This article belongs to the Section Inventions and Innovation in Energy and Thermal/Fluidic Science)

► Show Figures

Figure 1

Journal Description

Inventions

Latest Articles

Journal Menu

Journal Browser

Highly Accessed Articles

Latest Books

E-Mail Alert

News

Topics

Conferences

Special Issues

Further Information

Guidelines

MDPI Initiatives

Follow MDPI