Nothing Special   »   [go: up one dir, main page]

You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (5,385)

Search Parameters:
Keywords = industrial control system

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
14 pages, 464 KiB  
Article
Supply Chain Management Control in the Aerospace Sector: An Empirical Approach
by Gonzalo Torralba-Carnerero, Manuel García-Nieto, Juan Manuel Ramón-Jerónimo and Raquel Flórez-López
Logistics 2024, 8(4), 132; https://doi.org/10.3390/logistics8040132 (registering DOI) - 18 Dec 2024
Abstract
Introduction: The aerospace industry has been significantly disrupted by recent economic downturns, underscoring the need for robust supply chain management. This is especially important given the complexity of aircraft manufacturing, the globalization of supply chains, and the requirement to meet stringent regulatory [...] Read more.
Introduction: The aerospace industry has been significantly disrupted by recent economic downturns, underscoring the need for robust supply chain management. This is especially important given the complexity of aircraft manufacturing, the globalization of supply chains, and the requirement to meet stringent regulatory standards. While outsourcing is widely adopted to improve cost competitiveness, it also introduces risks, such as compromised product quality, inefficiency, and delays. Methods: This study explores how aerospace firms manage outsourcing relationships using control mechanisms. Data were gathered through seven semi-structured interviews with supply chain managers from contracting and supplier firms focusing on both formal and informal controls in supplier selection and relationship management. Results: Supplier selection is primarily guided by trust, past performance, and delivery reliability. Firms employ formal controls, such as KPIs and certifications, alongside informal practices, including embedding internal staff within supplier operations. This dual approach ensures quality, mitigates risks, and maintains compliance with regulatory standards. Conclusions: This study concludes that combining formal and informal controls is vital for balancing outsourcing efficiency with risk mitigation, offering valuable insights into supply chain management practices in regulated industries like aerospace. Full article
Show Figures

Figure 1

Figure 1
<p>Stages/suppliers in the aerospace supply chain, adapted from [<a href="#B2-logistics-08-00132" class="html-bibr">2</a>].</p>
Full article ">
16 pages, 3151 KiB  
Article
Influence of Anthropogenic and Climatic Factors on the Dynamics of Nitrogen and Phosphorus in an Urbanized River Basin
by Qinghuan Zhang, Fuzhen Liu, Fenfang Tan and Abdul Qadeer
Water 2024, 16(24), 3635; https://doi.org/10.3390/w16243635 - 17 Dec 2024
Abstract
The management of and reduction in ammonia nitrogen (NH3-N) and total phosphorus (TP) in the water environment are crucial for protecting water quality amid rapid urbanization and population growth in highly industrialized regions. Specifically, in the Xiangjiang River Basin, the development [...] Read more.
The management of and reduction in ammonia nitrogen (NH3-N) and total phosphorus (TP) in the water environment are crucial for protecting water quality amid rapid urbanization and population growth in highly industrialized regions. Specifically, in the Xiangjiang River Basin, the development of the Chang–Zhu–Tan urban agglomeration resulted in the deterioration of river water quality in the past, where ammonia nitrogen (NH3-N) and total phosphorus (TP) were the dominant pollutants. This study aims to assess the influence of anthropogenic and climatic factors on the dynamics of nitrogen and phosphorus in an urbanized river basin in the middle Xiangjiang River Basin, China, from 2016 to 2020. This study examines NH3-N and TP trends and their influencing factors across six tributaries, as well as how their concentrations have changed in response to urbanization and wastewater treatment management. The results reveal that average NH3-N and TP concentrations decreased from 2016 to 2020 in the urbanized river system. NH3-N and TP concentrations exhibited positive correlations with the proportion of cropland and negative correlations with population number, percentages of urban lands, and forests. In contrast, the influence of precipitation and streamflow on NH3-N and TP concentrations was relatively weak. Consequently, agricultural activity was the primary contributing factor to NH3-N and TP concentrations. Our study also suggests that the government’s newly implemented water protection regulations can effectively control pollutant levels in urbanized river basins. Full article
(This article belongs to the Special Issue Contaminants in the Water Environment)
Show Figures

Figure 1

Figure 1
<p>Location map of the (<b>a</b>) study area and the sampling sites in Changsha city, with the Xiangjiang River and six tributary rivers; (<b>b</b>) land use types in 2020 [<a href="#B25-water-16-03635" class="html-bibr">25</a>]; (<b>c</b>) population number [<a href="#B15-water-16-03635" class="html-bibr">15</a>].</p>
Full article ">Figure 2
<p>Time series of NH<sub>3</sub>-N and TP concentrations in (<b>a1</b>,<b>a2</b>) Jinjiang, (<b>b1</b>,<b>b2</b>) Liuyang, (<b>c1</b>,<b>c2</b>) Laodao, (<b>d1</b>,<b>d2</b>) Weishui, (<b>e1</b>,<b>e2</b>) Xiangjiang, (<b>f1</b>,<b>f2</b>) Longwanggang, and (<b>g1</b>,<b>g2</b>) Shahe rivers. Colored lines III, IV, and V refer to Grade III, IV, and V national standards for NH<sub>3</sub>-N and TP concentrations, respectively. Longwanggang and Shahe rivers have available data from August 2017 to December 2020, so their figures were drawn on a different <span class="html-italic">x</span>-axis compared to other rivers. The vertical dashed lines represent the points in time when NH<sub>3</sub>-N or TP levels changed from one grade to another.</p>
Full article ">Figure 3
<p>Percent of urban lands (<b>a</b>), percent of forest (<b>b</b>), percent of croplands (<b>c</b>), and population number (<b>d</b>) in the six tributary river catchments from 2016 to 2020.</p>
Full article ">Figure 4
<p>Correlation heatmaps of water quality parameters in the Xiangjiang River and its tributary rivers. In the circles, * represents <span class="html-italic">p</span> &lt; 0.05, ** represents <span class="html-italic">p</span> &lt; 0.01, and *** represents <span class="html-italic">p</span> &lt; 0.001; correlation coefficients close to 0 are shown as blank.</p>
Full article ">Figure 5
<p>Time series of WQI in the Xiangjiang River and its six tributary rivers.</p>
Full article ">Figure 6
<p>Correlation coefficients between main land use types and population number, and (<b>a</b>) NH<sub>3</sub> and (<b>b</b>) TP concentrations. * <span class="html-italic">p</span>-value &lt; 0.05, which is corrected using the Benjamini–Hochberg correction method; pop is population number; Longwg represents Longwanggang.</p>
Full article ">Figure 7
<p>Pearson’s correlation coefficients between NH<sub>3</sub>-N (left column) and TP (right column) and climatic variables during (<b>a</b>,<b>b</b>) the whole time period, (<b>c</b>,<b>d</b>) the wet season, and (<b>e</b>,<b>f</b>) the dry season in the six rivers. One star represents corrected <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">
20 pages, 4665 KiB  
Review
Review on Advanced Model Predictive Control Technologies for High-Power Converters and Industrial Drives
by Zeyi Yu and Jiang Long
Electronics 2024, 13(24), 4969; https://doi.org/10.3390/electronics13244969 - 17 Dec 2024
Abstract
Model predictive control (MPC) has emerged as a very popular control technology. This paper presents and discusses the major applications and recent research advances of MPC in the field of high-power converters and industrial drives. The classic concepts and implementation principles of MPC [...] Read more.
Model predictive control (MPC) has emerged as a very popular control technology. This paper presents and discusses the major applications and recent research advances of MPC in the field of high-power converters and industrial drives. The classic concepts and implementation principles of MPC for power electronic control are reviewed, followed by the classification and application schemes of MPC in electrical drive systems. This paper discusses typical MPC techniques. Based on the results of extensive discussions on the latest research, this paper analyzes some key application issues of MPC in industrial control solutions, including the optimization and elimination of weighting factors, improvement of steady-state performance, and robustness improvement. It also covers research trends in advanced MPC. By reviewing advanced MPC solutions, this paper contributes to enhancing the performance in applications of high-power converters and industrial drives, and providing multiple perspectives to improve control performance of MPC. The presented content aims to provide readers with a precise overview and facilitate their future research in this attractive area. Full article
(This article belongs to the Special Issue High Performance Control and Industrial Applications)
Show Figures

Figure 1

Figure 1
<p>Classification of MPC strategies.</p>
Full article ">Figure 2
<p>Two-level voltage source inverter and fundamental VVs: (<b>a</b>) 2L-VSI, (<b>b</b>) fundamental VV distribution.</p>
Full article ">Figure 3
<p>General control structure of MPC.</p>
Full article ">Figure 4
<p>Common optimization tools for MPC.</p>
Full article ">Figure 5
<p>MPC methods from the perspective of control theory.</p>
Full article ">Figure 6
<p>Typical structure diagram of the industrial transmission system.</p>
Full article ">Figure 7
<p>Typical applications of MPC for high-power converters [<a href="#B30-electronics-13-04969" class="html-bibr">30</a>,<a href="#B31-electronics-13-04969" class="html-bibr">31</a>,<a href="#B32-electronics-13-04969" class="html-bibr">32</a>,<a href="#B33-electronics-13-04969" class="html-bibr">33</a>,<a href="#B34-electronics-13-04969" class="html-bibr">34</a>].</p>
Full article ">Figure 8
<p>Typical applications of MPC for high-power converters.</p>
Full article ">Figure 9
<p>Structure diagram of conventional MPCC.</p>
Full article ">Figure 10
<p>Structure diagram of conventional MPTC.</p>
Full article ">Figure 11
<p>Optimization and elimination of weighting factor.</p>
Full article ">
26 pages, 1750 KiB  
Review
The Global Challenge of Fluoride Contamination: A Comprehensive Review of Removal Processes and Implications for Human Health and Ecosystems
by Vivek Mariappan Santhi, Diwahar Periasamy, Muthumari Perumal, Prasanth Morkondan Sekar, Varalakshmi Varatharajan, Dhandapani Aravind, Krishnasamy Senthilkumar, Sundaresan Thirumalai Kumaran, Saood Ali, Subramanipillai Sankar, Nivetha Vijayakumar, Charubala Boominathan and Ragulasangeerthian Suresh Krishnan
Sustainability 2024, 16(24), 11056; https://doi.org/10.3390/su162411056 - 17 Dec 2024
Viewed by 70
Abstract
Water resources are vital for humanity, but their quality has degraded in recent years due to increasing industrial activities. One significant issue is fluoride contamination, prevalent worldwide. Fluorides exist in combined states such as calcium fluoride, fluorapatite, and cryolite, originating from industrial processes [...] Read more.
Water resources are vital for humanity, but their quality has degraded in recent years due to increasing industrial activities. One significant issue is fluoride contamination, prevalent worldwide. Fluorides exist in combined states such as calcium fluoride, fluorapatite, and cryolite, originating from industrial processes like aluminum and fertilizer manufacturing. The World Health Organization warns against fluoride levels above 1.5 mg/L in drinking water due to health risks, including dental and skeletal fluorosis. Industrial activities also release fluoride-containing wastes into the environment, endangering ecosystems and human health. Overexposure to fluoride leads to disorders affecting organs including the kidneys, liver, and nervous system. Despite fluoride’s benefits in controlled doses, excessive intake causes health problems, as evidenced by rising dental fluorosis cases in Brazil. Thus, effective and affordable fluoride removal strategies are crucial. Various methods exist, including adsorption, membrane technology, ion exchange process, electrodialysis, and electrocoagulation. Regulation of fluoride levels in drinking water is imperative to safeguard public health from its detrimental long-term effects. Full article
Show Figures

Figure 1

Figure 1
<p>Utilization of adsorbents for the removal of fluoride.</p>
Full article ">Figure 2
<p>Adsorbents for fluoride removal.</p>
Full article ">Figure 3
<p>Ion exchange fluoride removal.</p>
Full article ">Figure 4
<p>Removal of fluoride through coagulation.</p>
Full article ">
16 pages, 655 KiB  
Article
Adapting Management Control Systems to Organizational Contingency Factors: A Study of Moroccan Industrial Companies
by Hind Hammouch, Otilia Manta and Maria Palazzo
Businesses 2024, 4(4), 883-898; https://doi.org/10.3390/businesses4040048 - 16 Dec 2024
Viewed by 110
Abstract
This study investigates how organizational contingency factors, namely company size, environmental uncertainty, technological capacity, and organizational structure, affect the design and effectiveness of management control systems (MCS) in Moroccan industrial companies. Drawing on contingency theory, which emphasizes the alignment of organizational systems with [...] Read more.
This study investigates how organizational contingency factors, namely company size, environmental uncertainty, technological capacity, and organizational structure, affect the design and effectiveness of management control systems (MCS) in Moroccan industrial companies. Drawing on contingency theory, which emphasizes the alignment of organizational systems with contextual factors, this research applies quantitative methods to a sample of 190 industrial firms in Morocco, achieving a 76% response rate to the distributed surveys. The data are analyzed using correlation and linear regression techniques to explore these relationships. The findings reveal that larger firms, those operating in dynamic and uncertain environments, and those with advanced technological systems tend to implement more sophisticated, integrated, and participative MCS. Furthermore, flexible and decentralized organizational structures significantly enhance the adoption of adaptive control systems. These results underscore the importance of tailoring MCS to organizational characteristics and environmental conditions, particularly in emerging market contexts. This study’s novel contribution lies in its application of contingency theory to a non-Western industrial context, addressing a gap in the literature by demonstrating how specific regional factors influence MCS practices. This research offers practical insights for Moroccan industrial firms seeking to improve their operational efficiency, adaptability, and strategic decision making in volatile markets. Full article
Show Figures

Figure 1

Figure 1
<p>This study’s conceptual model. Source: elaborated by the authors.</p>
Full article ">Figure 2
<p>Final validated research model. Source: elaborated by the authors.</p>
Full article ">
22 pages, 1883 KiB  
Article
Resilient, Adaptive Industrial Self-X AI Pipeline with External AI Services: A Case Study on Electric Steelmaking
by Petri Kannisto, Zeinab Kargar, Gorka Alvarez, Bernd Kleimt and Asier Arteaga
Processes 2024, 12(12), 2877; https://doi.org/10.3390/pr12122877 - 16 Dec 2024
Viewed by 293
Abstract
The introduction of Self-X capabilities into industrial control offers a tremendous potential in the development of resilient, adaptive production systems that enable circular economy. The Self-X capabilities, powered by Artificial Intelligence (AI), can monitor the production performance and enable timely reactions to problems [...] Read more.
The introduction of Self-X capabilities into industrial control offers a tremendous potential in the development of resilient, adaptive production systems that enable circular economy. The Self-X capabilities, powered by Artificial Intelligence (AI), can monitor the production performance and enable timely reactions to problems or suboptimal operation. This paper presents a concept and prototype for Self-X AI in the process industry, particularly electric steelmaking with the EAF (Electric Arc Furnace). Due to complexity, EAF operation should be optimized with computational models, but these suffer from the fluctuating composition of the input materials, i.e., steel scrap. The fluctuation can be encountered with the Self-X method that monitors the performance, detecting anomalies and suggesting the re-training and re-initialization of models. These suggestions support the Human-in-the-Loop (HITL) in managing the AI models and in operating the production processes. The included Self-X capabilities are self-detection, self-evaluation, and self-repair. The prototype proves the concept, showing how the optimizing AI pipeline receives alarms from the external AI services if the performance degrades. The results of this work are encouraging and can be generalized, especially to processes that encounter drift related to the conditions, such as input materials for circular economy. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
Show Figures

Figure 1

Figure 1
<p>The cycles of the research methodology illustrated.</p>
Full article ">Figure 2
<p>The Self-X optimization scheme, including HITL and the external, supportive AI services.</p>
Full article ">Figure 3
<p>The architecture of the Self-X AI Pipeline; each component is positioned within the reference architecture.</p>
Full article ">Figure 4
<p>An alarm is delivered from External AI services to the data scientist. If the data scientist confirms the alarm, AI Data Pipeline will refresh the optimization models.</p>
Full article ">Figure 5
<p>The components of the prototype.</p>
Full article ">Figure 6
<p>The alarms generated by the AI methods for the different stages of the AI pipeline are displayed in the dashboard (<b>left</b>). These alerts are categorized into different types (<b>right</b>).</p>
Full article ">Figure 7
<p>The alarms generated by the AI methods for the cumulative amount of secondary oxygen in the transformation stage are shown in the upper plot. The raw data for the cumulative amount of secondary oxygen are shown in the lower graph, with the alarm-triggering periods indicated by red rectangles.</p>
Full article ">Figure 8
<p>Autonomic Manager generates alarms based on predefined rules applied to metadata at the various stages of the AI pipeline, categorizing the alarms into different types.</p>
Full article ">Figure 9
<p>Alarms generated by the Autonomic Manager for model degradation.</p>
Full article ">Figure 10
<p>Scrap characterization calculates a chemical analysis for different scrap types.</p>
Full article ">Figure 11
<p>Scrap mix optimization recommends the optimal scrap mix for the furnace, taking into account the target steel grade, scrap availability, and cost.</p>
Full article ">
21 pages, 3863 KiB  
Article
IoRT-Based Middleware for Heterogeneous Multi-Robot Systems
by Emil Cuadros Zegarra, Dennis Barrios Aranibar and Yudith Cardinale
J. Sens. Actuator Netw. 2024, 13(6), 87; https://doi.org/10.3390/jsan13060087 - 16 Dec 2024
Viewed by 194
Abstract
The concurrence of social robots with different functionalities and cyber-physical systems in indoor environments has recently been increasing in many fields, such as medicine, education, and industry. In such scenarios, the collaboration of such heterogeneous robots demands effective communication for task completion. The [...] Read more.
The concurrence of social robots with different functionalities and cyber-physical systems in indoor environments has recently been increasing in many fields, such as medicine, education, and industry. In such scenarios, the collaboration of such heterogeneous robots demands effective communication for task completion. The concept of the Internet of Robotic Things (IoRT) is introduced as a potential solution, leveraging technologies like Artificial Intelligence, Cloud Computing, and Mesh Networks. This paper proposes an IoRT-based middleware that allows the communication of different types of robot operating systems in dynamic environments, using a cloud-based protocol. This middleware facilitates task assignment, training, and planning for heterogeneous robots, while enabling distributed communication via WiFi. The system operates in two control modes: local and cloud-based, for flexible communication and information distribution. This work highlights the challenges of current communication methods, particularly in ensuring information reach, agility, and handling diverse robots. To demonstrate the middleware suitability and applicability, an implementation of a proof-of-concept is shown in a touristic scenario where several guide robots can collaborate by effectively sharing information gathered from their heterogeneous sensor systems, with the aid of cloud processing or even internal communication processes. Results show that the performance of the middleware allows real-time applications for heterogeneous multi-robot systems in different domains. Full article
(This article belongs to the Section Communications and Networking)
Show Figures

Figure 1

Figure 1
<p>Workflow for task assignment in multi-robot systems [<a href="#B26-jsan-13-00087" class="html-bibr">26</a>].</p>
Full article ">Figure 2
<p>IoRT = IoT + Cloud Robotics [<a href="#B14-jsan-13-00087" class="html-bibr">14</a>].</p>
Full article ">Figure 3
<p>Publisher/subscriber model [<a href="#B34-jsan-13-00087" class="html-bibr">34</a>].</p>
Full article ">Figure 4
<p>Proposed middleware for communication in heterogeneous multi-robot systems.</p>
Full article ">Figure 5
<p>Message package structure of protocol model.</p>
Full article ">Figure 6
<p>Main program flowchart of <span class="html-italic">Cloud Server</span>.</p>
Full article ">Figure 7
<p>Client communication with server flowchart.</p>
Full article ">Figure 8
<p>Publish process in <span class="html-italic">Server</span> flowchart.</p>
Full article ">Figure 9
<p>Subscribe process in server flowchart.</p>
Full article ">Figure 10
<p>Messages published and subscribed by each Robot Node.</p>
Full article ">Figure 11
<p>Average time for publishing package to be sent from <span class="html-italic">Robot Node</span> to <span class="html-italic">Server</span>.</p>
Full article ">Figure 12
<p>Average time for subscribing package to be sent from <span class="html-italic">Robot Node</span> to <span class="html-italic">Server</span>.</p>
Full article ">Figure 13
<p>Percentage of correct packages delivered from <span class="html-italic">Robot Nodes</span> to <span class="html-italic">Server</span>.</p>
Full article ">Figure 14
<p>Moving Turtlebot4 (images above) and Turtlesim (images below) using publish and subscribe in middleware.</p>
Full article ">
20 pages, 313 KiB  
Review
Opportunities and Challenges of Artificial Intelligence Applied to Identity and Access Management in Industrial Environments
by Jesús Vegas and César Llamas
Future Internet 2024, 16(12), 469; https://doi.org/10.3390/fi16120469 - 16 Dec 2024
Viewed by 280
Abstract
The integration of artificial intelligence(AI) technologies into identity and access management (IAM) systems has greatly improved access control and management, offering more robust, adaptive, and intelligent solutions than traditional methods. AI-driven IAM systems enhance security, operational efficiency, and introduce new capabilities in industrial [...] Read more.
The integration of artificial intelligence(AI) technologies into identity and access management (IAM) systems has greatly improved access control and management, offering more robust, adaptive, and intelligent solutions than traditional methods. AI-driven IAM systems enhance security, operational efficiency, and introduce new capabilities in industrial environments. In this narrative review, we present the state-of-the-art AI technologies in industrial IAM, focusing on methods such as biometric, comprising facial and voice recognition, and multifactor authentication for robust security. It addresses the challenges and solutions in implementing AI-based IAM systems in industrial settings, including security, privacy, evaluation, and continuous improvement. We present also the emerging trends and future directions, highlighting AI’s potential to transform industrial security measures. This review aims to guide researchers and practitioners in developing and implementing next-generation access control systems, proposing future research directions to address challenges and optimize AI applications in this domain. Full article
Show Figures

Figure 1

Figure 1
<p>Overview of an IAM system and main components of an identity and access management system in relation to an industrial environment [<a href="#B2-futureinternet-16-00469" class="html-bibr">2</a>,<a href="#B25-futureinternet-16-00469" class="html-bibr">25</a>,<a href="#B26-futureinternet-16-00469" class="html-bibr">26</a>]. (Figure developed by the authors.)</p>
Full article ">Figure 2
<p>Main topics in AI-based IAM systems arranged from core techniques and challenges to main concerns and goals as stated in this survey by the authors. (Figure developed by the authors.)</p>
Full article ">
20 pages, 8594 KiB  
Article
Synchronization of an On-Board Photovoltaic Converter Under Conditions of High Dynamic Voltage Frequency Change
by Tomasz Binkowski, Ľubomír Beňa, Dušan Medveď and Paweł Pijarski
Energies 2024, 17(24), 6302; https://doi.org/10.3390/en17246302 - 13 Dec 2024
Viewed by 327
Abstract
The decarbonization of energy systems is forcing the development of renewable energy generation and consumption technologies. Photovoltaic systems are being used in almost every industry, including autonomous power systems used on ships, space vehicles, or flying platforms, where the voltage supplying specific equipment [...] Read more.
The decarbonization of energy systems is forcing the development of renewable energy generation and consumption technologies. Photovoltaic systems are being used in almost every industry, including autonomous power systems used on ships, space vehicles, or flying platforms, where the voltage supplying specific equipment can change in an overridingly controlled manner. Feeding energy from a renewable source into a power system with highly dynamic frequency changes is not possible for traditional grid converter control strategies. This is caused by the synchronization system, which is designed for a fixed value of the grid voltage frequency, and by the proportional-resonant controllers used. In this paper, it is shown that frequency tracking correction causes deviations from the unit amplitude of synchronization signals, causing errors in the reference signals responsible for the active and reactive components of the converter current. To solve this problem, a new variable frequency adaptation system using a generalized second-order integrator was proposed. As a result, synchronization signals of unit amplitude were obtained. Due to the proposed method, the proportional-resonant controller was able to control the active and reactive components of the current even when the voltage frequency changes, adjusting the resonant frequency. Full article
(This article belongs to the Section F3: Power Electronics)
Show Figures

Figure 1

Figure 1
<p>Block diagram of a photovoltaic converter system connected to an alternating-current voltage bus of variable frequency.</p>
Full article ">Figure 2
<p>Trajectories of changes in frequency (<b>a</b>) and amplitude (<b>b</b>) of voltage at the point of connection of the grid converter.</p>
Full article ">Figure 3
<p>Generator voltage waveform at the connection point of the grid converter.</p>
Full article ">Figure 4
<p>Bode plots of the generalized second-order integrator for frequency <span class="html-italic">f</span> = 500 Hz: signal of the fundamental component <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> </semantics></math> (<b>a</b>); signal of the orthogonal component <math display="inline"><semantics> <mrow> <msub> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> (<b>b</b>).</p>
Full article ">Figure 5
<p>Block structure of the generalized second-order integrator.</p>
Full article ">Figure 6
<p>The voltage waveform <span class="html-italic">v</span> and the quadrature signal estimates <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> </semantics></math><span class="html-italic"><sub>q</sub></span> obtained by direct implementation of the frequency variation profile <span class="html-italic">f</span> in the generalized second-order integrator.</p>
Full article ">Figure 7
<p>Trajectory of quadrature signals formed in the generalized second-order integrator for (<b>a</b>) ω = 500 Hz, (<b>b</b>) ω = 100 Hz.</p>
Full article ">Figure 8
<p>Trajectory of quadrature signals formed in a generalized second-order integrator for a given frequency variation profile.</p>
Full article ">Figure 9
<p>Flow chart of the proposed characteristic frequency reference system.</p>
Full article ">Figure 10
<p>Graphic illustration describing the adaptive zero-order hold block process.</p>
Full article ">Figure 11
<p>Structure of the RSG system and waveforms describing the operation of AZOH.</p>
Full article ">Figure 12
<p>The proposed system of adaptive regulation of the grid converter.</p>
Full article ">Figure 13
<p>Test stand designed for testing grid-tied inverters.</p>
Full article ">Figure 14
<p>Trajectory of quadrature signals formed in a generalized second-order integrator for a proposed RSG with AZOH.</p>
Full article ">Figure 15
<p>The trajectory modulus of quadrature signals with a frequency drop of 1.42 Hz per millisecond without (<b>a</b>) and with AZOH (<b>b</b>).</p>
Full article ">Figure 16
<p>The trajectory modulus of quadrature signals with a frequency drop of 2.84 Hz per millisecond without (<b>a</b>) and with AZOH (<b>b</b>).</p>
Full article ">Figure 17
<p>The trajectory modulus of quadrature signals with a frequency drop of 13.3 Hz per millisecond without (<b>a</b>) and with AZOH (<b>b</b>).</p>
Full article ">Figure 18
<p>Percentage change in amplitude of the quadrature signal versus steepness of frequency change.</p>
Full article ">Figure 19
<p>Response of the synchronizer in the form of quadrature signals <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <msub> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> to the input signal <span class="html-italic">v<sub>i</sub></span> for: step change in the frequency of the input signal (<b>a</b>); step change in the phase angle (<b>b</b>); step change in the frequency during its linear reduction (<b>c</b>); step change in the phase angle during frequency reduction (<b>d</b>).</p>
Full article ">Figure 20
<p>Response of the synchronizer in the form of quadrature signals <math display="inline"><semantics> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> </semantics></math> and <math display="inline"><semantics> <mrow> <msub> <mrow> <mover accent="true"> <mrow> <mi>v</mi> </mrow> <mo stretchy="false">^</mo> </mover> </mrow> <mrow> <mi>q</mi> </mrow> </msub> </mrow> </semantics></math> for: fundamental component <span class="html-italic">v<sub>i</sub></span> disturbed by the third harmonic (<b>a</b>); fundamental component <span class="html-italic">v<sub>i</sub></span> disturbed by the white noise (<b>b</b>).</p>
Full article ">Figure 21
<p>Current and voltage waveforms of the mains inverter measured on Bus 2 with non-zero active component and zero reactive component.</p>
Full article ">Figure 22
<p>Current and voltage waveforms of the mains inverter measured on Bus 2 with the same active and reactive component.</p>
Full article ">
26 pages, 3317 KiB  
Review
A Comprehensive Review on Technologies for Achieving Zero-Energy Buildings
by Yushi Wang, Beining Hu, Xianhai Meng and Runjin Xiao
Sustainability 2024, 16(24), 10941; https://doi.org/10.3390/su162410941 - 13 Dec 2024
Viewed by 461
Abstract
The booming of the building industry has led to a sharp increase in energy consumption. The advancement of zero-energy buildings (ZEBs) is of great significance in mitigating climate change, improving energy efficiency, and thus realizing sustainable development of buildings. This paper reviews the [...] Read more.
The booming of the building industry has led to a sharp increase in energy consumption. The advancement of zero-energy buildings (ZEBs) is of great significance in mitigating climate change, improving energy efficiency, and thus realizing sustainable development of buildings. This paper reviews the recent progress of key technologies utilized in ZEBs, including energy-efficient measures (EEMs), renewable energy technologies (RETs), and building energy management system (BEMS), aiming to provide reference and support of the wider implementation of ZEBs. EEMs can reduce energy demand by optimizing the envelope design, phase change materials integration, efficient HVAC systems, and user behavior. The renewable energy sources discussed here are solar, biomass, wind, and geothermal energy, including distributed energy systems introduced to integrated various renewable resources and meet users’ demand. This study focuses on the application of building energy management in ZEBs, including energy use control, fault detection and diagnosis, and management optimization. The recent development of these three technologies mainly focuses on the combination with artificial intelligence (AI). In addition, this paper also emphasizes possible future research works about user behavior and zero-energy communities to improve the energy efficiency from a more complicated perspective. Full article
(This article belongs to the Special Issue Net-Zero-Energy Building Solutions for Sustainability)
Show Figures

Figure 1

Figure 1
<p>Amount of literature on ZEBs in different databases in 2013–2023.</p>
Full article ">Figure 2
<p>Density visualization of ZEBs research in 2013–2023.</p>
Full article ">Figure 3
<p>The trend of keyword co-occurrence of EEMs in ZEBs research from 2017 to 2022.</p>
Full article ">Figure 4
<p>The trend of keyword co-occurrence of RETs in ZEBs research from 2018–2021.</p>
Full article ">Figure 5
<p>The trend of keyword co-occurrence of BEMS in ZEBs research from 2019 to 2021.</p>
Full article ">Figure 6
<p>Number of published papers on building energy management in ZEBs from 2018 to 2023.</p>
Full article ">Figure 7
<p>Keyword co-occurrence of intelligent BEMSs in ZEBs research from 2020 to 2023.</p>
Full article ">Figure A1
<p>The framework of the research methodology in this work [<a href="#B136-sustainability-16-10941" class="html-bibr">136</a>].</p>
Full article ">
17 pages, 7893 KiB  
Article
Modern SCADA for CSP Systems Based on OPC UA, Wi-Fi Mesh Networks, and Open-Source Software
by Jose Antonio Carballo, Javier Bonilla, Jesús Fernández-Reche, Antonio Luis Avila-Marin and Blas Díaz
Energies 2024, 17(24), 6284; https://doi.org/10.3390/en17246284 - 13 Dec 2024
Viewed by 318
Abstract
This study presents a methodology for the development of modern Supervisory Control and Data Acquisition (SCADA) systems aimed at improving the operation and management of concentrated solar power (CSP) plants, leveraging the tools provided by industrial digitization. This approach is exemplified by its [...] Read more.
This study presents a methodology for the development of modern Supervisory Control and Data Acquisition (SCADA) systems aimed at improving the operation and management of concentrated solar power (CSP) plants, leveraging the tools provided by industrial digitization. This approach is exemplified by its application to the CESA-I central tower heliostat field at the Plataforma Solar de Almería (PSA), one of the oldest CSP facilities in the world. The goal was to upgrade the control and monitoring capabilities of the heliostat field by integrating modern technologies such as OPC (Open Platform Communications)) Unified Architecture (UA), a Wi-Fi mesh communication network, and a custom Python-based gateway for interfacing with legacy MODBUS systems. Performance tests demonstrated stable, scalable communication, efficient real-time control, and seamless integration of new developments (smart heliostat) into the existing infrastructure. The SCADA system also introduced a user-friendly Python-based interface developed with PySide6, significantly enhancing operational efficiency and reducing task complexity for system operators. The results show that this low-cost methodology based on open-source software provides a flexible and robust SCADA architecture, suitable for future CSP applications, with potential for further optimization through the incorporation of artificial intelligence (AI) and machine learning. Full article
(This article belongs to the Special Issue Advances in Solar Thermal Energy Harvesting, Storage and Conversion)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>CESA-I system captions.</p>
Full article ">Figure 2
<p>SCADA CESA-I architecture.</p>
Full article ">Figure 3
<p>CESA-Modbus library polling function.</p>
Full article ">Figure 4
<p>SCADA main window (1—heliostat field, 2—information, 3—control, 4—logging and console).</p>
Full article ">Figure 5
<p>Meteorological data subsection.</p>
Full article ">Figure 6
<p>Central subsection of the main area.</p>
Full article ">Figure 7
<p>Legend subsection of the main area.</p>
Full article ">Figure 8
<p>Information area.</p>
Full article ">Figure 9
<p>Control area.</p>
Full article ">Figure 10
<p>Login area.</p>
Full article ">Figure 11
<p>Login area.</p>
Full article ">Figure 12
<p>Heliostat window.</p>
Full article ">Figure 13
<p>Smart heliostat control window.</p>
Full article ">
31 pages, 18233 KiB  
Review
Research Status and Applications of Dual-Frequency Induction Heating Power Supply
by Xingru Chen, Jianchao Wang, Bendong Ma, Zhongxia Duan and Houshen Wang
Electronics 2024, 13(24), 4913; https://doi.org/10.3390/electronics13244913 - 12 Dec 2024
Viewed by 370
Abstract
The advent of dual-frequency induction heating (DFIH) technology has revolutionized modern industrial applications by providing flexible regulation of the heating process, significantly boosting heating efficiency, and optimizing energy utilization. This comprehensive review delves into the state-of-the-art research on DFIH power supplies, with a [...] Read more.
The advent of dual-frequency induction heating (DFIH) technology has revolutionized modern industrial applications by providing flexible regulation of the heating process, significantly boosting heating efficiency, and optimizing energy utilization. This comprehensive review delves into the state-of-the-art research on DFIH power supplies, with a particular emphasis on their topological structures, output power control mechanisms, and resonant network configurations. The paper critically examines the challenges inherent to this technology, such as enhancing power density and ensuring system stability. It also highlights recent innovations in multi-inverter bridge topologies, resonant circuit optimization, and the implementation of intelligent control algorithms. Case studies are employed to illustrate the practical applications of DFIH in metal processing and composite material treatment, showcasing its potential to revolutionize these industries. The review concludes by delineating future research directions, with a focus on the integration of multi-frequency technologies and the development of efficient control strategies, thereby setting the stage for the next generation of induction heating systems. Full article
(This article belongs to the Section Industrial Electronics)
Show Figures

Figure 1

Figure 1
<p>Schematic diagram of induction heating principle.</p>
Full article ">Figure 2
<p>Relationship between current density and distance from object surface.</p>
Full article ">Figure 3
<p>Development timeline of induction heating technology.</p>
Full article ">Figure 4
<p>Typical induction heating system composition diagram.</p>
Full article ">Figure 5
<p>Structure diagram of induction heating power supply system.</p>
Full article ">Figure 6
<p>DFIH technology development history diagram.</p>
Full article ">Figure 7
<p>Typical composition diagram of a DFIH power supply.</p>
Full article ">Figure 8
<p>Structure of single-inverter bridge synchronous dual-frequency power supply.</p>
Full article ">Figure 9
<p>NPC three-level DFIH power supply topology.</p>
Full article ">Figure 10
<p>Simulation waveforms of output voltage for NPC H-bridge inverter: (<b>a</b>) graph of output voltage over time; (<b>b</b>) graph of output voltage vs. frequency.</p>
Full article ">Figure 11
<p>CHB (2-Unit) multilevel conversion circuit.</p>
Full article ">Figure 12
<p>PWM control flowchart.</p>
Full article ">Figure 13
<p>Overall efficiencies against duty-ratio from Reference [<a href="#B56-electronics-13-04913" class="html-bibr">56</a>]: (<b>a</b>) overall efficiency against D<sub>1</sub> with D<sub>h</sub> = 0.95; (<b>b</b>) overall efficiency against D<sub>h</sub> with D<sub>1</sub> = 0.95. (D<sub>1</sub>: duty-ratios for low-frequency legs; D<sub>h</sub>: duty-ratios for high-frequency legs).</p>
Full article ">Figure 14
<p>Experimental result from Reference [<a href="#B58-electronics-13-04913" class="html-bibr">58</a>]: (<b>a</b>) output currents vs. D<sub>2</sub> (D<sub>1</sub> = 0.93); (<b>b</b>) output currents vs. D<sub>1</sub> (D<sub>2</sub> = 0.98); (<b>c</b>) Load-2 output power vs. D<sub>2</sub>; (<b>d</b>) Load-1 output power vs. D<sub>1</sub>.</p>
Full article ">Figure 14 Cont.
<p>Experimental result from Reference [<a href="#B58-electronics-13-04913" class="html-bibr">58</a>]: (<b>a</b>) output currents vs. D<sub>2</sub> (D<sub>1</sub> = 0.93); (<b>b</b>) output currents vs. D<sub>1</sub> (D<sub>2</sub> = 0.98); (<b>c</b>) Load-2 output power vs. D<sub>2</sub>; (<b>d</b>) Load-1 output power vs. D<sub>1</sub>.</p>
Full article ">Figure 15
<p>Experimental result from reference [<a href="#B59-electronics-13-04913" class="html-bibr">59</a>,<a href="#B60-electronics-13-04913" class="html-bibr">60</a>]: (<b>a</b>) I<sub>lf</sub> and I<sub>hf</sub> vs. low-frequency inverter duty cycle (D<sub>l</sub>); (<b>b</b>) I<sub>lf</sub> and I<sub>hf</sub> vs. high-frequency inverter duty cycle (D<sub>h</sub>); (<b>c</b>) overall efficiency vs. D<sub>l</sub>; (<b>d</b>) overall efficiency vs. D<sub>h</sub>.</p>
Full article ">Figure 15 Cont.
<p>Experimental result from reference [<a href="#B59-electronics-13-04913" class="html-bibr">59</a>,<a href="#B60-electronics-13-04913" class="html-bibr">60</a>]: (<b>a</b>) I<sub>lf</sub> and I<sub>hf</sub> vs. low-frequency inverter duty cycle (D<sub>l</sub>); (<b>b</b>) I<sub>lf</sub> and I<sub>hf</sub> vs. high-frequency inverter duty cycle (D<sub>h</sub>); (<b>c</b>) overall efficiency vs. D<sub>l</sub>; (<b>d</b>) overall efficiency vs. D<sub>h</sub>.</p>
Full article ">Figure 16
<p>Control block diagram of the grid-connected photovoltaic dual-frequency inverter.</p>
Full article ">Figure 17
<p>Three-leg dual-frequency inverter topology with a loaded resonant circuit from reference.</p>
Full article ">Figure 18
<p>Graphs showing independent control and efficiency from reference [<a href="#B64-electronics-13-04913" class="html-bibr">64</a>]: (<b>a</b>) i<sub>lf</sub> and i<sub>hf</sub> versus duty cycle (D<sub>i</sub>) of the low-frequency inverter; (<b>b</b>) i<sub>lf</sub> and i<sub>hr</sub> versus duty cycle (D<sub>h</sub>) of the high-frequency inverter; (<b>c</b>) overall efficiency versus duty cycle of the low-frequency inverter; (<b>d</b>) overall efficiency versus duty cycle of the high-frequency inverter.</p>
Full article ">Figure 19
<p>Basic topology of resonant circuit: (<b>a</b>) series resonance; (<b>b</b>) parallel resonance.</p>
Full article ">Figure 20
<p>DFIH power supply topology based on LCCL network.</p>
Full article ">Figure 21
<p>DFIH power supply topology based on LC resonant network.</p>
Full article ">Figure 22
<p>Topology of the first type of quasi-resonant inverter circuit.</p>
Full article ">Figure 23
<p>DFIH power supply topology based on LC resonant network.</p>
Full article ">Figure 24
<p>Three types of multi-resonant converters: (<b>a</b>) HB; (<b>b</b>) FB; (<b>c</b>) three phase.</p>
Full article ">Figure 25
<p>Impedance matching of dual-frequency heating system.</p>
Full article ">Figure 26
<p>Dual-frequency quenching site.</p>
Full article ">Figure 27
<p>Induction heating in free zone.</p>
Full article ">Figure 28
<p>DFIH with multiple outputs: (<b>a</b>) single load—single high-frequency inverter system; (<b>b</b>) multiple loads—single high-frequency inverter system.</p>
Full article ">
23 pages, 472 KiB  
Review
Exploring the Effects of Synergistic Combustion of Alcohols and Biodiesel on Combustion Performance and Emissions of Diesel Engines: A Review
by Fangyuan Zheng and Haeng Muk Cho
Energies 2024, 17(24), 6274; https://doi.org/10.3390/en17246274 (registering DOI) - 12 Dec 2024
Viewed by 383
Abstract
Diesel engines are extensively employed in transportation, agriculture, and industry due to their high thermal efficiency and fuel economy. However, the combustion of conventional diesel fuel is accompanied by substantial emissions of pollutants, including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx [...] Read more.
Diesel engines are extensively employed in transportation, agriculture, and industry due to their high thermal efficiency and fuel economy. However, the combustion of conventional diesel fuel is accompanied by substantial emissions of pollutants, including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and carbon dioxide (CO2), posing significant threats to environmental quality. Biodiesel, as a renewable and cleaner alternative fuel, can significantly reduce emissions of CO, HC, and particulate matter (PM) due to its unique molecular structure. Nonetheless, its lower calorific value and poor cold-start performance limit its application, while its high oxygen content may contribute to increased NOx emissions. To address these limitations, researchers have proposed blending biodiesel with alcohol-based fuels such as methanol, ethanol, or butanol to create synergistic combustion systems that optimize engine performance and emission characteristics. This paper systematically reviews the effects of alcohol fuels on the performance and emission characteristics of biodiesel blends in diesel engines. Studies indicate that the addition of alcohol fuels can significantly enhance engine performance by improving fuel atomization, extending ignition delay, and increasing premixed combustion efficiency. These enhancements result in higher cylinder pressure, net heat release rate (HRR), and brake thermal efficiency (BTE), while reducing brake-specific fuel consumption (BSFC) to some extent. Moreover, most studies report that alcohol fuels help reduce CO, HC, smoke, and NOx emissions but tend to increase CO2 emissions. However, some findings suggest that in certain cases, the opposite results may occur. The impact of different types of alcohol fuels on performance and emissions varies significantly, requiring a comprehensive evaluation of their properties, such as latent heat, viscosity, and oxygen content. Although the appropriate addition of alcohol fuels demonstrates substantial potential for optimizing engine performance and reducing emissions, excessive blending may lead to adverse effects, necessitating careful control of the blending ratio. Future research should consider mixing two or more alcohol fuels with biodiesel to explore synergistic effects beyond the capabilities of single alcohols. Additionally, further studies should focus on optimizing fuel compositions and emission control strategies for varying operating conditions. Full article
(This article belongs to the Special Issue Combustion of Alternative Fuel Blends)
Show Figures

Figure 1

Figure 1
<p>Types of raw materials for producing biofuels [<a href="#B12-energies-17-06274" class="html-bibr">12</a>].</p>
Full article ">
20 pages, 11490 KiB  
Article
Characteristic Analysis and Error Compensation Method of Space Vector Pulse Width Modulation-Based Driver for Permanent Magnet Synchronous Motors
by Qihang Chen, Wanzhen Wu and Qianen He
Sensors 2024, 24(24), 7945; https://doi.org/10.3390/s24247945 - 12 Dec 2024
Viewed by 280
Abstract
Permanent magnet synchronous motors (PMSMs) are widely used in a variety of fields such as aviation, aerospace, marine, and industry due to their high angular position accuracy, energy conversion efficiency, and fast response. However, driving errors caused by the non-ideal characteristics of the [...] Read more.
Permanent magnet synchronous motors (PMSMs) are widely used in a variety of fields such as aviation, aerospace, marine, and industry due to their high angular position accuracy, energy conversion efficiency, and fast response. However, driving errors caused by the non-ideal characteristics of the driver negatively affect motor control accuracy. Compensating for the errors arising from the non-ideal characteristics of the driver demonstrates substantial practical value in enhancing control accuracy, improving dynamic performance, minimizing vibration and noise, optimizing energy efficiency, and bolstering system robustness. To address this, the mechanism behind these non-ideal characteristics is analyzed based on the principles of space vector pulse width modulation (SVPWM) and its circuit structure. Tests are then conducted to examine the actual driver characteristics and verify the analysis. Building on this, a real-time compensation method is proposed, physically matched to the driver. Using the volt–second equivalence principle, an input–output voltage model of the driver is derived, with model parameters estimated from test data. The driving error is then compensated with a voltage method based on the model. The results of simulations and experiments show that the proposed method effectively mitigates the influence of the driver’s non-ideal characteristics, improving the driving and speed control accuracies by 88.07% (reducing the voltage error from 0.7345 V to 0.0879 V for a drastic command voltage with a sinusoidal amplitude of 10 V and a frequency of 50 Hz) and 53.08% (reducing the speed error from 0.0130°/s to 0.0061°/s for a lower command speed with a sinusoidal amplitude of 20° and a frequency of 0.1 Hz), respectively, in terms of the root mean square errors. This method is cost-effective, practical, and significantly enhances the control performance of PMSMs. Full article
Show Figures

Figure 1

Figure 1
<p>Drive–control system for PMSMs.</p>
Full article ">Figure 2
<p>(<b>a</b>) Equivalent circuit diagram of the SVPWM driver. (<b>b</b>) Vector diagram of the space voltage.</p>
Full article ">Figure 3
<p>Dead time effect on the IGBT conduction and output voltages. (<b>a</b>) The ideal control signals for the pair of switches. (<b>b</b>) The control signals with dead time for the pair of switches. (<b>c</b>) Electric potential of the <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>1</mn> </mrow> </msub> <mo>−</mo> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>4</mn> </mrow> </msub> </mrow> </semantics></math> connection point (a phase terminal).</p>
Full article ">Figure 4
<p>Schematic diagram of the internal structure of an IGBT. (<b>a</b>) Basic structure; (<b>b</b>) equivalent circuit.</p>
Full article ">Figure 5
<p>IGBT on–off time test circuit.</p>
Full article ">Figure 6
<p>(<b>a</b>) Comparison of the voltage <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>R</mi> </mrow> </msub> </mrow> </semantics></math> when switching on (<math display="inline"><semantics> <mrow> <mi>R</mi> <mo>=</mo> <mn>10</mn> <mtext> </mtext> <mi mathvariant="sans-serif">Ω</mi> </mrow> </semantics></math>). (<b>b</b>) Switch-on voltages for different resistances (<math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mn>30</mn> <mtext> </mtext> <mi mathvariant="normal">V</mi> </mrow> </semantics></math>).</p>
Full article ">Figure 7
<p>(<b>a</b>) Comparison of the voltage <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>R</mi> </mrow> </msub> </mrow> </semantics></math> when switching off (<math display="inline"><semantics> <mrow> <mi>R</mi> <mo>=</mo> <mn>10</mn> <mtext> </mtext> <mi mathvariant="sans-serif">Ω</mi> </mrow> </semantics></math>). (<b>b</b>) Comparison of the voltage <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>R</mi> </mrow> </msub> </mrow> </semantics></math> when switching off (<math display="inline"><semantics> <mrow> <mi>R</mi> <mo>=</mo> <mn>9</mn> <mtext> </mtext> <mi mathvariant="normal">K</mi> <mi mathvariant="sans-serif">Ω</mi> </mrow> </semantics></math>).</p>
Full article ">Figure 8
<p>Steady-state voltage <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi mathvariant="normal">∞</mi> </mrow> </msub> <mo>−</mo> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> </mrow> </semantics></math> relationship curve.</p>
Full article ">Figure 9
<p>(<b>a</b>) Fitting results of the turn-on process. (<b>b</b>) Fitting results of the turn-off process.</p>
Full article ">Figure 10
<p>(<b>a</b>) Graph of the pattern of change in <math display="inline"><semantics> <mrow> <mo>∆</mo> <mi>v</mi> </mrow> </semantics></math>. (<b>b</b>) Fitting result (<math display="inline"><semantics> <mrow> <mi>a</mi> </mrow> </semantics></math>).</p>
Full article ">Figure 11
<p>Schematic diagram of voltage compensation.</p>
Full article ">Figure 12
<p>(<b>a</b>) Phase voltage error before/after driver compensation. (<b>b</b>) Phase current error before/after driver compensation.</p>
Full article ">Figure 13
<p>(<b>a</b>) q-axis current before/after driver compensation. (<b>b</b>) Speed before/after driver compensation.</p>
Full article ">Figure 14
<p>Experimental platform.</p>
Full article ">Figure 15
<p>(<b>a</b>) Comparison of speed loop performance <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mn>20</mn> <mtext> </mtext> <mi mathvariant="normal">V</mi> </mrow> </semantics></math>. (<b>b</b>) Comparison of speed loop performance <math display="inline"><semantics> <mrow> <msub> <mrow> <mi>U</mi> </mrow> <mrow> <mi>d</mi> <mi>c</mi> </mrow> </msub> <mo>=</mo> <mn>30</mn> <mtext> </mtext> <mi mathvariant="normal">V</mi> </mrow> </semantics></math>.</p>
Full article ">Figure 16
<p>Magnitude of the synthetic voltage vector.</p>
Full article ">
15 pages, 2551 KiB  
Article
Oral Vaccine Formulation for Immunocastration Using a Live-Attenuated Salmonella ΔSPI2 Strain as an Antigenic Vector
by Sergio A. Bucarey, Lucy D. Maldonado, Francisco Duarte, Alejandro A. Hidalgo and Leonardo Sáenz
Vaccines 2024, 12(12), 1400; https://doi.org/10.3390/vaccines12121400 - 12 Dec 2024
Viewed by 350
Abstract
Immunization against Gonadotropin-Releasing Hormone (GnRH) has been successfully explored and developed for the parenteral inoculation of animals, aimed at controlling fertility, reducing male aggressiveness, and preventing boar taint. Although effective, these vaccines may cause adverse reactions at the injection site, including immunosuppression and [...] Read more.
Immunization against Gonadotropin-Releasing Hormone (GnRH) has been successfully explored and developed for the parenteral inoculation of animals, aimed at controlling fertility, reducing male aggressiveness, and preventing boar taint. Although effective, these vaccines may cause adverse reactions at the injection site, including immunosuppression and inflammation, as well as the involvement of laborious and time-consuming procedures. Oral vaccines represent an advancement in antigen delivery technology in the vaccine industry. In this study, a Salmonella enterica serovar Typhimurium (S. Typhimurium) mutant lacking the pathogenicity island 2 (S. Typhimurium ΔSPI2) was used as a vehicle and mucosal adjuvant to deliver two genetic constructs in an attempt to develop an oral immunological preparation against gonadotropin hormone-releasing hormone (GnRH). S. Typhimurium ΔSPI2 was transformed to carry two plasmids containing a modified GnRH gene repeated in tandem (GnRXG/Q), one under eukaryotic expression control (pDNA::GnRXG/Q) and another under prokaryotic expression control (pJexpress::GnRXG/Q). A group of three male BALB/c mice were orally immunized and vaccination-boosted 30 days later. The oral administration of S. Typhimurium ΔSPI2 transformed with both plasmids was effective in producing antibodies against GnRXG/Q, leading to a decrease in serum testosterone levels and testicular tissue atrophy, evidenced by a reduction in the transverse tubular diameter of the seminiferous tubules and a decrease in the number of layers of the seminiferous epithelium in the testes of the inoculated mice. These results suggest that S. Typhimurium ΔSPI2 can be used as a safe and simple system to produce an oral formulation against GnRH and that Salmonella-mediated oral antigen delivery is a novel, yet effective, alternative to induce an immune response against GnRH in a murine model, warranting further research in other animal species. Full article
(This article belongs to the Special Issue Research on Immune Response and Vaccines: 2nd Edition)
Show Figures

Figure 1

Figure 1
<p>Survival percentage of <span class="html-italic">S.</span> Typhimurium 14028s and <span class="html-italic">S.</span> Typhimurium 14028s ∆SPI2 in murine RAW264.7 macrophages. (<b>A</b>) Survival at 24 h post internalization. (<b>B</b>) Survival at 48 h post internalization. An intracellular survival assay was performed, and intracellular bacteria were recovered at the indicated times. Survival percentages were calculated from the bacteria recovered at t<sub>0</sub>. The bars represent the standard deviation (SD). The assays were performed in triplicate. (*) Indicates a significant difference with <span class="html-italic">p</span> &lt; 0.05 for the attenuated 14028s ∆SPI2 strain compared to the wild-type 14028s strain.</p>
Full article ">Figure 2
<p>Detection of GnRXG/Q by Western blot. An isolated colony of the recombinant strain <span class="html-italic">S.</span> Typhimurium 14028s ∆SPI2/pJEX was cultured in LB broth and induced with IPTG. The purified GnRXG/Q antigen (~30 kDa) was used as a positive control. The extracts were analyzed by Western blot. The band was photographed under a transilluminator. Lane 1 corresponds to the positive control (GnRXG/Q purified protein), and Lane 2 corresponds to the protein expressed in the recombinant strain <span class="html-italic">S.</span> Typhimurium 14028s ∆SPI2/pJEX.</p>
Full article ">Figure 3
<p>IgG anti-GnRXG/Q antibody levels expressed as arithmetic means of absorbance values measured at 450 nm on days 0, 15, 30, 45, and 60 post immunization. Male BALB/c mice (<span class="html-italic">n</span> = 3) were orally immunized on days 0 and 30 with 10<sup>9</sup> CFU of <span class="html-italic">S.</span> Typhimurium 14028s ΔSPI2/pDNAX3::GnRXG/Q (pDNAX3) with 10<sup>9</sup> CFU of <span class="html-italic">S.</span> Typhimurium 14028s ΔSPI2/pJEX::GnRXG/Q (pJEX), subcutaneously with 100 µg of GnRXG/Q purified by affinity chromatography using aluminum as an adjuvant (Control +), and orally with 200 µL of PBS (Control −). IgG anti-GnRXG/Q levels were measured by ELISA on days 0, 15, 30, 45, and 60 post immunization. (*) Indicates a significant difference with <span class="html-italic">p</span> &lt; 0.05 for any of the treated groups compared with the negative control.</p>
Full article ">Figure 4
<p>Serum testosterone concentration of the study animals, based on a standard curve. (<b>A</b>) Day 15 post immunization. (<b>B</b>) Day 30 post immunization. (<b>C</b>) Day 45 post immunization. Male BALB/c mice (<span class="html-italic">n</span> = 3) were orally immunized on days 0 and 30 with 10<sup>9</sup> CFU of <span class="html-italic">S.</span> Typhimurium 14028s ΔSPI2/pDNAX3::GnRXG/Q (pDNAX3) with 10<sup>9</sup> CFU of <span class="html-italic">S.</span> Typhimurium 14028s ΔSPI2/pJEX::GnRXG/Q (pJEX), subcutaneously with 100 µg of GnRXG/Q purified by affinity chromatography using aluminum as an adjuvant (Control +), and orally with 200 µL of PBS (Control −). Serum testosterone levels were measured by commercial ELISA (IBL-AMERICA kit) on days 15, 30, and 45 post immunization. (***) Indicates a difference of <span class="html-italic">p</span> &lt; 0.001 compared to the negative control. (**) Indicates a difference of <span class="html-italic">p</span> &lt; 0.01 compared to the negative control. (*) Indicates a difference of <span class="html-italic">p</span> &lt; 0.05 compared to the negative control.</p>
Full article ">Figure 5
<p>Histological sections of seminiferous tubules, stained with hematoxylin-eosin, observed at 40×. The images correspond to the negative control group immunized with 200 μL of oral PBS (<b>A</b>), the positive control group immunized subcutaneously with 100 μg of GnRXG/Q purified by aluminum affinity chromatography as an adjuvant (<b>B</b>), the experimental group orally immunized with strain <span class="html-italic">S.</span> Typhimurium 14028s ∆SPI2/pDNAX3, (<b>C</b>) and the experimental group immunized orally with strain <span class="html-italic">S.</span> Typhimurium 14028s ∆SPI2/pJEX (<b>D</b>). The black lines show the transverse tubular diameter, represented by the means of two diametrically opposed measurements. The black solid bar at the lower right corner of each figure is 100 µm long.</p>
Full article ">
Back to TopTop