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Keywords = comfort degradation

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27 pages, 19737 KiB  
Article
Effect of Landscape Architectural Characteristics on LST in Different Zones of Zhengzhou City, China
by Jiayue Xu, Le Xuan, Cong Li, Tianji Wu, Yajing Wang, Yutong Wang, Xuhui Wang and Yong Wang
Land 2025, 14(8), 1581; https://doi.org/10.3390/land14081581 - 2 Aug 2025
Viewed by 267
Abstract
The process of urbanization has intensified the urban heat environment, with the degradation of thermal conditions closely linked to the morphological characteristics of different functional zones. This study delineated urban functional areas using a multivariate dataset and investigated the seasonal and threshold effects [...] Read more.
The process of urbanization has intensified the urban heat environment, with the degradation of thermal conditions closely linked to the morphological characteristics of different functional zones. This study delineated urban functional areas using a multivariate dataset and investigated the seasonal and threshold effects of landscape and architectural features on land surface temperature (LST) through boosted regression tree (BRT) modeling and Spearman correlation analysis. The key findings are as follows: (1) LST exhibits significant seasonal variation, with the strongest urban heat island effect occurring in summer, particularly within industry, business, and public service zones; residence zones experience the greatest temperature fluctuations, with a seasonal difference of 24.71 °C between spring and summer and a peak temperature of 50.18 °C in summer. (2) Fractional vegetation cover (FVC) consistently demonstrates the most pronounced cooling effect across all zones and seasons. Landscape indicators generally dominate the regulation of LST, with their relative contribution exceeding 45% in green land zones. (3) Population density (PD) exerts a significant, seasonally dependent dual effect on LST, where strategic population distribution can effectively mitigate extreme heat events. (4) Mean building height (MBH) plays a vital role in temperature regulation, showing a marked cooling influence particularly in residence and business zones. Both the perimeter-to-area ratio (LSI) and frontal area index (FAI) exhibit distinct seasonal variations in their impacts on LST. (5) This study establishes specific indicator thresholds to optimize thermal comfort across five functional zones; for instance, FVC should exceed 13% in spring and 31.6% in summer in residence zones to enhance comfort, while maintaining MBH above 24 m further aids temperature regulation. These findings offer a scientific foundation for mitigating urban heat waves and advancing sustainable urban development. Full article
(This article belongs to the Special Issue Climate Adaptation Planning in Urban Areas)
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24 pages, 2070 KiB  
Article
Reinforcement Learning-Based Finite-Time Sliding-Mode Control in a Human-in-the-Loop Framework for Pediatric Gait Exoskeleton
by Matthew Wong Sang and Jyotindra Narayan
Machines 2025, 13(8), 668; https://doi.org/10.3390/machines13080668 - 30 Jul 2025
Viewed by 269
Abstract
Rehabilitation devices such as actuated lower-limb exoskeletons can provide essential mobility assistance for pediatric patients with gait impairments. Enhancing their control systems under conditions of user variability and dynamic disturbances remains a significant challenge, particularly in active-assist modes. This study presents a human-in-the-loop [...] Read more.
Rehabilitation devices such as actuated lower-limb exoskeletons can provide essential mobility assistance for pediatric patients with gait impairments. Enhancing their control systems under conditions of user variability and dynamic disturbances remains a significant challenge, particularly in active-assist modes. This study presents a human-in-the-loop control architecture for a pediatric lower-limb exoskeleton, combining outer-loop admittance control with robust inner-loop trajectory tracking via a non-singular terminal sliding-mode (NSTSM) controller. Designed for active-assist gait rehabilitation in children aged 8–12 years, the exoskeleton dynamically responds to user interaction forces while ensuring finite-time convergence under system uncertainties. To enhance adaptability, we augment the inner-loop control with a twin delayed deep deterministic policy gradient (TD3) reinforcement learning framework. The actor–critic RL agent tunes NSTSM gains in real-time, enabling personalized model-free adaptation to subject-specific gait dynamics and external disturbances. The numerical simulations show improved trajectory tracking, with RMSE reductions of 27.82% (hip) and 5.43% (knee), and IAE improvements of 40.85% and 10.20%, respectively, over the baseline NSTSM controller. The proposed approach also reduced the peak interaction torques across all the joints, suggesting more compliant and comfortable assistance for users. While minor degradation is observed at the ankle joint, the TD3-NSTSM controller demonstrates improved responsiveness and stability, particularly in high-load joints. This research contributes to advancing pediatric gait rehabilitation using RL-enhanced control, offering improved mobility support and adaptive rehabilitation outcomes. Full article
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18 pages, 2954 KiB  
Article
Effect of Rubber Granulate Content on the Compressive Strength of Concrete for Industrial Vibration-Isolating Floors
by Maciej Gruszczyński, Alicja Kowalska-Koczwara and Tadeusz Tatara
Materials 2025, 18(13), 3134; https://doi.org/10.3390/ma18133134 - 2 Jul 2025
Viewed by 341
Abstract
Ensuring vibration and impact isolation is crucial in industrial flooring design, especially where vibroacoustic comfort is a priority. Excessive vibrations can negatively affect sensitive equipment, structural durability, and personnel comfort. With the rise of automation and high-precision processes, effective vibration control in floor [...] Read more.
Ensuring vibration and impact isolation is crucial in industrial flooring design, especially where vibroacoustic comfort is a priority. Excessive vibrations can negatively affect sensitive equipment, structural durability, and personnel comfort. With the rise of automation and high-precision processes, effective vibration control in floor systems is increasingly important. Traditional solutions like elastomer pads, rubber mats, or floating floors often have high installation costs, complex construction, and long-term degradation. Therefore, there is growing interest in integrated, durable alternatives that can be incorporated directly into concrete structures. One such approach uses rubber granulates from recycled tires as a modifying additive in cementitious composites. This can improve damping, enhance impact energy absorption, and reduce the need for external insulating layers. However, adding rubber particles to concrete may affect its compressive strength, a key design parameter. This article presents experimental research on concrete and mortar mixtures modified with rubber granulates for vibration-isolating industrial floor systems. The proposed solution combines a conventional concrete subbase with a rubber-enhanced mortar layer, forming a composite system to mitigate vibration transmission. Laboratory tests and real-scale verification under industrial conditions showed that the slab with hybrid EPDM/SBR rubber granulate mortar achieved the highest vibration-damping efficiency, reducing vertical acceleration by 58.6% compared to the reference slab. The EPDM-only mortar also showed a significant reduction of 45.5%. Full article
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30 pages, 4875 KiB  
Article
Stochastic Demand-Side Management for Residential Off-Grid PV Systems Considering Battery, Fuel Cell, and PEM Electrolyzer Degradation
by Mohamed A. Hendy, Mohamed A. Nayel and Mohamed Abdelrahem
Energies 2025, 18(13), 3395; https://doi.org/10.3390/en18133395 - 27 Jun 2025
Viewed by 377
Abstract
The proposed study incorporates a stochastic demand side management (SDSM) strategy for a self-sufficient residential system powered from a PV source with a hybrid battery–hydrogen storage system to minimize the total degradation costs associated with key components, including Li-io batteries, fuel cells, and [...] Read more.
The proposed study incorporates a stochastic demand side management (SDSM) strategy for a self-sufficient residential system powered from a PV source with a hybrid battery–hydrogen storage system to minimize the total degradation costs associated with key components, including Li-io batteries, fuel cells, and PEM electrolyzers. The uncertainty in demand forecasting is addressed through a scenario-based generation to enhance the robustness and accuracy of the proposed method. Then, stochastic optimization was employed to determine the optimal operating schedules for deferable appliances and optimal water heater (WH) settings. The optimization problem was solved using a genetic algorithm (GA), which efficiently explores the solution space to determine the optimal operating schedules and reduce degradation costs. The proposed SDSM technique is validated through MATLAB 2020 simulations, demonstrating its effectiveness in reducing component degradation costs, minimizing load shedding, and reducing excess energy generation while maintaining user comfort. The simulation results indicate that the proposed method achieved total degradation cost reductions of 16.66% and 42.6% for typical summer and winter days, respectively, in addition to a reduction of the levelized cost of energy (LCOE) by about 22.5% compared to the average performance of 10,000 random operation scenarios. Full article
(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
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24 pages, 34320 KiB  
Case Report
A 10-Year Follow-Up of an Approach to Restore a Case of Extreme Erosive Tooth Wear
by Davide Foschi, Andrea Abate, Francesca Vailati, Ignazio Loi, Cinzia Maspero and Valentina Lanteri
Dent. J. 2025, 13(6), 259; https://doi.org/10.3390/dj13060259 - 10 Jun 2025
Viewed by 1336
Abstract
Background: In recent years, thanks to the improvement of adhesive techniques, patients affected by tooth wear, related to erosion and/or parafunctional habits, can undergo restoration by adding only what has been lost of their dentition (additive approach). However, since not all clinicians are [...] Read more.
Background: In recent years, thanks to the improvement of adhesive techniques, patients affected by tooth wear, related to erosion and/or parafunctional habits, can undergo restoration by adding only what has been lost of their dentition (additive approach). However, since not all clinicians are convinced that dental rehabilitation should be proposed in the early stages of exposed dentin, several treatments are often postponed. It is important to emphasize that, in the early stages, the clinical approach should remain conservative, focusing on dietary counseling, the modification of harmful habits, fluoride application, and risk factor management. Only when these preventive and non-invasive strategies prove insufficient, and the condition continues to progress, should invasive restorative treatments be considered. Unfortunately, epidemiological studies are reporting an increase in the number of young patients affected by erosive tooth wear, and not intercepting these cases earlier could lead to a severe degradation of the affected dentition. In addition, parafunctional habits are also becoming more frequent among patients. The combination of erosion and attrition can be very destructive, and may progress rapidly once dentin is exposed and the risk factors remain unaddressed. The aim of this report was to present a conservative full-mouth rehabilitation approach for severe erosive lesions and to provide a 10-year follow-up assessing the biological, functional, and esthetic outcomes. Methods: In this article, the postponed restorative treatment of a patient, suffering from severe tooth wear, is illustrated. The patient had sought dental treatment in the past; however, due to the already very compromised dentition, a conventional but very aggressive treatment was proposed and refused. Four years later, when the patient finally accepted an alternative conservative therapy, the tooth degradation was very severe, especially at the level of the maxillary anterior teeth. The combination of three different approaches, Speed-Up Therapy, BOPT (Biologically-Oriented Preparation Technique), and the 3 Step Technique, however, improved the capacity to successfully complete the difficult therapeutic task. Results: The biological goals (maintenance of the pulp vitality of all of the teeth and the minimal removal of healthy tooth structure) were accomplished, relying only on adhesive techniques. Conclusions: The overall treatment was very comfortable for the patient and less complicated for the clinician. At 10-year follow-up, biological, functional, and esthetic success was still confirmed. Full article
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30 pages, 7872 KiB  
Article
Vibration Response Characteristics of Prefabricated Frame Structures Around the Subway
by Zhenyu Huang and Youfa Yang
Appl. Sci. 2025, 15(12), 6419; https://doi.org/10.3390/app15126419 - 7 Jun 2025
Viewed by 368
Abstract
Prefabricated structures have gained wider application. However, there is little research on the vibration response of prefabricated frame structures in subway environments. Prolonged metro-induced vibrations may severely degrade human comfort levels for nearby residents, interfere with the operation of precision instruments, and accelerate [...] Read more.
Prefabricated structures have gained wider application. However, there is little research on the vibration response of prefabricated frame structures in subway environments. Prolonged metro-induced vibrations may severely degrade human comfort levels for nearby residents, interfere with the operation of precision instruments, and accelerate structural fatigue damage. Consequently, it is imperative to investigate the vibration response patterns of prefabricated frame structures under metro operational conditions. Structural vibration responses demonstrated greater sensitivity to column sections and slab thickness than beam dimensions when using semirigid connections, though marginal effects emerged with parameter increases. Enhanced vibration thresholds require supplementary vibration reduction measures. Increasing total spans proved more effective in vibration reduction than adding stories, with vibration transmission exhibiting notable edge effects. Related research can provide reference for the structural design of prefabricated frame structures around the subway. Full article
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33 pages, 1737 KiB  
Article
Interactive Map of Stakeholders’ Journey in Construction: Focus on Waste Management and Circular Economy
by Maurício de Oliveira Gondak, Guilherme Francisco do Prado, Cleiton Hluszko, Jovani Taveira de Souza and Antonio Carlos de Francisco
Sustainability 2025, 17(11), 5195; https://doi.org/10.3390/su17115195 - 5 Jun 2025
Viewed by 740
Abstract
The transition toward sustainability in the construction industry requires integrated tools that align with circular economy principles. This study introduces the Interactive Stakeholder Journey Map in Construction (ISJMC), an innovative visual and systemic tool that supports waste management and circularity throughout the life [...] Read more.
The transition toward sustainability in the construction industry requires integrated tools that align with circular economy principles. This study introduces the Interactive Stakeholder Journey Map in Construction (ISJMC), an innovative visual and systemic tool that supports waste management and circularity throughout the life cycle of construction assets. Although the sector is economically significant, it remains one of the main contributors to environmental degradation due to high resource consumption and low waste recovery rates. Developed according to EN 15643-3:2012, a European standard that provides a framework for assessing the social sustainability of construction works, focusing on aspects such as accessibility, health, and comfort and grounded in the Design Thinking methodology, ISJMC enables mapping stakeholder interactions, touchpoints, and responsibilities across all life cycle stages, including initiative, design, procurement, construction, use, and end of life. A systematic literature review and collaborative workshops guided the tool’s development and validation. The application in a real case involving a medium-sized Brazilian construction company helped identify significant pain points and opportunities for implementing circular practices. The results demonstrate that ISJMC (i) facilitates a systemic and visual understanding of material and information flows, (ii) promotes transparent mapping of resource value to support better decision-making, and (iii) encourages the identification of circularity opportunities while fostering collaboration among stakeholders. The tool revealed critical challenges related to waste generation and management. It supported co-creating sustainable strategies, including improved material selection, lean construction practices, and stronger supplier engagement. By translating complex standards into accessible visual formats, ISJMC contributes to the academic field, supports practical applications, and offers a foundation for expanding circular approaches in construction projects. Full article
(This article belongs to the Special Issue Sustainability: Resources and Waste Management)
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26 pages, 6952 KiB  
Article
Development of a Bicycle Road Surface Roughness and Risk Assessment Method Using Smartphone Sensor Technology
by Dong-youn Lee, Ho-jun Yoo, Jae-yong Lee and Gyeong-ok Jeong
Sensors 2025, 25(11), 3520; https://doi.org/10.3390/s25113520 - 3 Jun 2025
Viewed by 614
Abstract
Surface roughness is a key factor influencing the safety, comfort, and overall quality of bicycle lanes, which are increasingly integrated into urban transportation systems worldwide. This study aims to assess and quantify the roughness of bicycle lanes in Sejong City, Republic of Korea, [...] Read more.
Surface roughness is a key factor influencing the safety, comfort, and overall quality of bicycle lanes, which are increasingly integrated into urban transportation systems worldwide. This study aims to assess and quantify the roughness of bicycle lanes in Sejong City, Republic of Korea, by utilizing accelerometer-based sensor technologies. Five study sections (A–E) were selected to represent a range of road surface conditions, from newly constructed roads to severely deteriorated surfaces. These sections were chosen based on bicycle traffic volume and prior reports of pavement degradation. The evaluation of road surface roughness was conducted using a smartphone-mounted accelerometer to measure the vertical, lateral, and longitudinal accelerations. The data collected were used to calculate the Bicycle Road Roughness Index (BRI) and Faulting Impact Index (FII), which provide a quantitative measure of road conditions and the impact of surface defects on cyclists. Field surveys, conducted in 2022, identified significant variation in roughness across the study sections, with values of BRI ranging from 0.2 to 0.8. Sections with a BRI greater than 0.5 were considered unsafe for cyclists. The FII showed a clear relationship between bump size and cycling speed, with higher bump sizes and faster cycling speeds leading to significantly increased impact forces on cyclists. These findings highlight the importance of using quantitative metrics to assess bicycle lane conditions and provide actionable data for maintenance planning. The results suggest that the proposed methodology could serve as a reliable tool for the evaluation and management of bicycle lane infrastructure, contributing to the improvement of cycling safety and comfort. Full article
(This article belongs to the Special Issue Advanced Sensing and Analysis Technology in Transportation Safety)
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18 pages, 2127 KiB  
Article
Practical Validation of nearZEB Residential Power Supply Model with Renewable Electricity Brought into the Building Using Electric Vehicles (via V2G) Instead of the Distribution Network
by Jacek A. Biskupski
Energies 2025, 18(11), 2786; https://doi.org/10.3390/en18112786 - 27 May 2025
Viewed by 458
Abstract
This article attempts to estimate the potential of supplying a residential building in Europe with energy exclusively from RESs during a whole year, including the heating period. The aim of the tests carried out was to minimize the purchase of energy required to [...] Read more.
This article attempts to estimate the potential of supplying a residential building in Europe with energy exclusively from RESs during a whole year, including the heating period. The aim of the tests carried out was to minimize the purchase of energy required to achieve the thermal comfort (HVACR + DHW) of a residential building powered solely by electricity. During the tests carried out, the EVs were used by the residents as their daily means of transport, topped up during working hours, and the excess energy remaining in their batteries was discharged into the building when they returned home. Energy for the EVs/PHEVs was sourced from RESs (mostly for free) while they were parked at the workplace, and also on the way home. Two one-month tests in the spring and autumn resulted in a state where, instead of purchasing a significant volume of black energy from the grid, the building was mostly powered by green energy from roof-top PVs and RES energy brought in by the PHEVs/EVs. This study identified days when the building became a real nZEB, which was not possible in previous years. The results of economic gains and carbon footprint reduction were calculated. After a period of testing, the degree of degradation of traction batteries used to carry the energy of EVs/PHEVs was checked. A high potential for such an operation was identified, especially in areas where there are periodic shutdowns (due to a call from the grid operator) of local RESs situated near the residential areas. The proposed solution may be of interest to all countries where the use of grid energy is associated not only with a doubling of costs (grid charges), but also with significant emissions, particularly in the heating period (e.g., Poland). Full article
(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
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42 pages, 2459 KiB  
Review
Climate-Responsive Design of Photovoltaic Façades in Hot Climates: Materials, Technologies, and Implementation Strategies
by Xiaohui Wu, Yanfeng Wang, Shile Deng and Ping Su
Buildings 2025, 15(10), 1648; https://doi.org/10.3390/buildings15101648 - 14 May 2025
Cited by 2 | Viewed by 1540
Abstract
With the intensification of global climate change, buildings in hot climate zones face increasing challenges related to high energy consumption and thermal comfort. Building integrated photovoltaic (BIPV) façades, which combine power generation and energy saving potential, require further optimization in their climate-adaptive design. [...] Read more.
With the intensification of global climate change, buildings in hot climate zones face increasing challenges related to high energy consumption and thermal comfort. Building integrated photovoltaic (BIPV) façades, which combine power generation and energy saving potential, require further optimization in their climate-adaptive design. Most existing studies primarily focus on the photoelectric conversion efficiency of PV modules, yet there is a lack of systematic analysis of the coupled effects of temperature, humidity, and solar radiation intensity on PV performance. Moreover, the current literature rarely addresses the regional material degradation patterns, integrated cooling solutions, or intelligent control systems suitable for hot and humid climates. There is also a lack of practical, climate specific design guidelines that connect theoretical technologies with real world applications. This paper systematically reviews BIPV façade design strategies following a climate zoning framework, summarizing research progress from 2019 to 2025 in the areas of material innovation, thermal management, light regulation strategies, and parametric design. A climate responsive strategy is proposed to address the distinct challenges of humid hot and dry hot climates. Finally, this study discusses the barriers and challenges of BIPV system applications in hot climates and highlights future research directions. Unlike previous reviews, this paper offers a multi-dimensional synthesis that integrates climatic classification, material suitability, passive and active cooling strategies, and intelligent optimization technologies. It further provides regionally differentiated recommendations for façade design and outlines a unified framework to guide future research and practical deployment of BIPV systems in hot climates. Full article
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23 pages, 7646 KiB  
Article
Temporal Stability of Signal Quality in Non-Contact Biopotential Electrodes
by Antonio Stanešić, Luka Klaić, Dino Cindrić and Mario Cifrek
Sensors 2025, 25(10), 3077; https://doi.org/10.3390/s25103077 - 13 May 2025
Viewed by 519
Abstract
Non-contact electrodes have garnered significant attention as an alternative non-invasive biopotential measurement method that offers advantages such as improved subject comfort and ease of integration into everyday environments. Despite these benefits, ensuring consistent signal quality over time remains a critical challenge, particularly in [...] Read more.
Non-contact electrodes have garnered significant attention as an alternative non-invasive biopotential measurement method that offers advantages such as improved subject comfort and ease of integration into everyday environments. Despite these benefits, ensuring consistent signal quality over time remains a critical challenge, particularly in applications like electrocardiography (ECG), where accuracy and reliability are paramount. This study investigates the temporal stability of signal quality in non-contact biopotential electrodes, with a primary focus on ECG monitoring. Our measurements showed a significant change in the recorded signal quality during prolonged measurement periods, which impacts the integrity and reliability of the measurements. Furthermore, it significantly impacts any shorter (<10 min) consecutive measurements of influential parameters (such as properties of electrodes, dielectric, etc.) since it removes the crucial ceteris paribus principle: the signal may not change just due to the change in influential parameters, but also due to the passage of time. Through a series of controlled experiments, we analyze how factors such as temperature, pressure on the electrodes, and humidity influence signal quality over extended durations (10 min or more). The results demonstrate key insights into the temporal dynamics of non-contact electrode performance, identifying potential sources of signal degradation and avenues for mitigation. Full article
(This article belongs to the Special Issue Sensing Signals for Biomedical Monitoring)
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14 pages, 5866 KiB  
Article
Core-Sheath Structured Yarn for Biomechanical Sensing in Health Monitoring
by Wenjing Fan, Cheng Li, Bingping Yu, Te Liang, Junrui Li, Dapeng Wei and Keyu Meng
Biomimetics 2025, 10(5), 304; https://doi.org/10.3390/biomimetics10050304 - 9 May 2025
Viewed by 666
Abstract
The rapidly evolving field of functional yarns has garnered substantial research attention due to their exceptional potential in enabling next-generation electronic textiles for wearable health monitoring, human–machine interfaces, and soft robotics. Despite notable advancements, the development of yarn-based strain sensors that simultaneously achieve [...] Read more.
The rapidly evolving field of functional yarns has garnered substantial research attention due to their exceptional potential in enabling next-generation electronic textiles for wearable health monitoring, human–machine interfaces, and soft robotics. Despite notable advancements, the development of yarn-based strain sensors that simultaneously achieve high flexibility, stretchability, superior comfort, extended operational stability, and exceptional electrical performance remains a critical challenge, hindered by material limitations and structural design constraints. Here, we present a bioinspired, hierarchically structured core-sheath yarn sensor (CSSYS) engineered through an efficient dip-coating process, which synergistically integrates the two-dimensional conductive MXene nanosheets and one-dimensional silver nanowires (AgNWs). Furthermore, the sensor is encapsulated using a yarn-based protective layer, which not only preserves its inherent flexibility and wearability but also effectively mitigates oxidative degradation of the sensitive materials, thereby significantly enhancing long-term durability. Drawing inspiration from the natural architecture of plant stems—where the inner core provides structural integrity while a flexible outer sheath ensures adaptive protection—the CSSYS exhibits outstanding mechanical and electrical performance, including an ultralow strain detection limit (0.05%), an ultrahigh gauge factor (up to 744.45), rapid response kinetics (80 ms), a broad sensing range (0–230% strain), and exceptional cyclic stability (>20,000 cycles). These remarkable characteristics enable the CSSYS to precisely capture a broad spectrum of physiological signals, ranging from subtle arterial pulsations and respiratory rhythms to large-scale joint movements, demonstrating its immense potential for next-generation wearable health monitoring systems. Full article
(This article belongs to the Special Issue Bio-Inspired Flexible Sensors)
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22 pages, 23599 KiB  
Article
Effects of Defrost-Initiation Criteria and Orientations of an Outdoor Heat Exchanger on the Performance of an Automotive Reversible CO2 Heat Pump
by Wenying Zhang, Wenzhe Li and Pega Hrnjak
Energies 2025, 18(9), 2244; https://doi.org/10.3390/en18092244 - 28 Apr 2025
Viewed by 412
Abstract
Heat pump (HP) technology has been widely adopted in electric vehicles (EVs) for cabin and battery heating in cold weather due to its high efficiency. However, when an HP works under low ambient temperatures and high humidity, frost grows on the surface of [...] Read more.
Heat pump (HP) technology has been widely adopted in electric vehicles (EVs) for cabin and battery heating in cold weather due to its high efficiency. However, when an HP works under low ambient temperatures and high humidity, frost grows on the surface of the outdoor evaporator, deteriorating system efficiency. This study experimentally investigated the performance of an automotive reversible CO2 HP system under cyclic frosting–defrosting conditions, with different defrost-initiation criteria and orientations of the outdoor heat exchanger. The relationship between the performance degradation of the heat pump system and the feature of frost accumulation on the outdoor heat exchanger is analyzed. The experimental data revealed that the heating capacity of the HP system only mildly degrades (~30%), even with an air-side pressure drop of the outdoor heat exchanger growing 10 times, which enables the system to work in HP mode for a longer time before the defrosting without significantly impacting passengers’ comfort. The horizontally installed outdoor heat exchanger is proven to have better refrigerant distribution, but with approximately a 0.16 bar (11.9%) higher pressure drop, reducing the evaporating temperature by about 0.4 K. Consequently, frost accumulates faster, and the working time in HP mode is shortened by 12 min (18.2%). Moreover, the vertical outdoor heat exchanger drains much more water during the defrosting. As a result, the defrosting time for the vertical outdoor heat exchanger is reduced by 17%. Full article
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22 pages, 991 KiB  
Article
Strategies to Redress the Resilience of Residential Buildings Following Climatic Impacts: Perspectives from the UK Construction Industry
by Ehis Lawrence Onus, Ezekiel Chinyio, Emmanuel Itodo Daniel and Michael Gerges
Sustainability 2025, 17(8), 3426; https://doi.org/10.3390/su17083426 - 11 Apr 2025
Viewed by 424
Abstract
Housing environments are designed to provide comfort and protection but climate change has compromised the resilience of residential buildings. This study examines the impacts of climate change on UK residential buildings, identifying key vulnerabilities and adaptation strategies. A qualitative approach was used, involving [...] Read more.
Housing environments are designed to provide comfort and protection but climate change has compromised the resilience of residential buildings. This study examines the impacts of climate change on UK residential buildings, identifying key vulnerabilities and adaptation strategies. A qualitative approach was used, involving ten semi-structured interviews with experts. A thematic analysis of the interview transcripts using NVivo (V.14) software revealed connections between climate change drivers and building factors such as location, age, orientation, typology, and material integrity. Adverse effects on buildings and occupants include structural degradation, increased energy demands, and indoor discomfort. This study underscores the importance of multi-stakeholder collaboration among housing owners, community members, construction professionals, and policymakers to enhance the resilience of buildings. Construction professionals are seen as key players in the implementation of mitigation and adaptation measures. This study emphasises the need for proactive adaptation measures, informed policy interventions, and improved construction practices to safeguard housing against climate change. It contributes to understanding the effects of climate change on UK residential buildings and offers strategic insights for improving their resilience. Full article
(This article belongs to the Section Green Building)
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19 pages, 6585 KiB  
Article
Development of Co-Axial Fibres Composed of CA (Mn 50,000) and PEGs (600 and 1000): Evaluation of the Influence of the Coagulation Bath
by Nathalia Hammes, José Monteiro, Iran Rocha Segundo, Helena P. Felgueiras, M. Manuela Silva, Manuel F. M. Costa and Joaquim Carneiro
Appl. Sci. 2025, 15(6), 3028; https://doi.org/10.3390/app15063028 - 11 Mar 2025
Viewed by 696
Abstract
Rapid urbanisation and industrialisation have intensified the Urban Heat Island (UHI) effect, significantly increasing energy demand for thermal comfort. Urban buildings consume considerable energy throughout the year, which can be reduced by incorporating Phase Change Materials (PCMs) into building materials. PCMs effectively regulate [...] Read more.
Rapid urbanisation and industrialisation have intensified the Urban Heat Island (UHI) effect, significantly increasing energy demand for thermal comfort. Urban buildings consume considerable energy throughout the year, which can be reduced by incorporating Phase Change Materials (PCMs) into building materials. PCMs effectively regulate temperature by storing and releasing heat as latent heat during phase transitions. However, to prevent leakage, PCMs can be encapsulated in co-axial polymeric Phase Change Fibres (PCFs), representing an innovative approach in scientific research. This study optimised the coagulation bath and produced PCFs using commercial cellulose acetate as the sheath and polyethylene glycol (PEG 600 and 1000) as the core via the wet-spinning method. The first part of this work investigated the coagulation bath using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) analyses of the characteristic peak areas. In contrast, the second part examined the PCFs’ morphological, chemical and thermal properties using Bright-field microscopy, ATR-FTIR, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) techniques. The results demonstrated the successful production of PCFs with an optimised coagulation bath. Bright-field microscopy and ATR-FTIR confirmed the well-defined morphology and the presence of PEG in the fibre core. TGA analysis showed high thermal stability in the PCFs, with mass loss observed at high degradation temperatures, ranging from ~264 °C to 397 °C for the PCFs with PEG 600 and from ~273 °C to 413 °C for the PCFs with PEG 1000. Meanwhile, DSC analysis revealed melting points of ~12.64 °C and 11.04 °C, with endothermic enthalpy of ~39.24 °C and 30.59 °C and exothermic enthalpy of ~50.17 °C and 40.93 °C, respectively, for PCFs with PEG 600, and melting points of ~40.32 °C and 41.13 °C, with endothermic enthalpy of ~83.47 °C and 98.88 °C and exothermic enthalpy of ~84.66 °C and 88.79 °C, respectively, for PCFs with PEG 1000. These results validate the potential of PCFs for applications in building materials for civil engineering, promoting thermal efficiency and structural stability. Full article
(This article belongs to the Section Materials Science and Engineering)
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