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Keywords = thermal response of bridge

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16 pages, 1508 KB  
Article
Shape-Sensing Robotic-Assisted Bronchoscopic Microwave Ablation for Primary and Metastatic Pulmonary Nodules: Retrospective Case Series
by Liqin Xu, Russell Miller, Mitchell Zhao, Grace Lin, Wenduo Gu, Niral Patel, Keriann Van Nostrand, Jorge A. Munoz Pineda, Bryce Duchman, Brian Tran and George Cheng
Diagnostics 2025, 15(24), 3248; https://doi.org/10.3390/diagnostics15243248 - 18 Dec 2025
Abstract
Background: Bronchoscopic thermal ablation has emerged as a minimally invasive therapeutic option for managing pulmonary nodules in patients unsuitable for surgery or radiotherapy. Robotic-assisted bronchoscopy (RAB) offers enhanced stability and precise navigation, potentially improving the safety and accuracy of bronchoscopic ablation. However, clinical [...] Read more.
Background: Bronchoscopic thermal ablation has emerged as a minimally invasive therapeutic option for managing pulmonary nodules in patients unsuitable for surgery or radiotherapy. Robotic-assisted bronchoscopy (RAB) offers enhanced stability and precise navigation, potentially improving the safety and accuracy of bronchoscopic ablation. However, clinical data on RAB-guided microwave ablation (MWA) remains limited. Therefore, further evidence is needed to evaluate its feasibility, safety, and early therapeutic performance. Methods: We conducted a single-center retrospective feasibility study of shape-sensing RAB-guided MWA (ssRAB-MWA) for pulmonary nodules between October 2024 and September 2025. Eligible lesions (≤3.0 cm) included both primary lung cancers and metastatic nodules. All procedures were performed under general anesthesia using the ssRAB system integrated with cone-beam CT for intra-procedural confirmation. Technical success, safety outcomes, and short-term efficacy were assessed. Results: Nine patients (with 11 lesions: 3 primary, 8 metastatic) underwent ssRAB-MWA with 100% technical success. The median ablation time per nodule was 10 min (range, 1–26). One patient developed post-ablation pneumonia requiring hospitalization; no pneumothorax, major bleeding, or airway injury occurred. All lesions exhibited a transient increase in size immediately following MWA, followed by gradual reduction or stabilization over time. PET-CT evaluation demonstrated metabolic remission in primary lesions, with one patient achieving pathologic complete response after surgery. Conclusions: ssRAB-MWA appears to be a feasible and safe navigation-guided technique for small pulmonary lesions, offering encouraging early local control in both primary and metastatic lung cancers. This platform may expand the therapeutic spectrum of interventional pulmonology, bridging diagnosis and local therapy. Larger multicenter studies are warranted to validate long-term outcomes. Full article
(This article belongs to the Special Issue Advances in Interventional Pulmonology)
37 pages, 3631 KB  
Article
Research on Unified Information Modeling and Cross-Protocol Real-Time Interaction Mechanisms for Multi-Energy Supply Systems in Green Buildings
by Xue Li, Haotian Ge and Bining Huang
Sustainability 2025, 17(24), 11230; https://doi.org/10.3390/su172411230 - 15 Dec 2025
Viewed by 76
Abstract
Green buildings increasingly couple electrical, thermal, and hydrogen subsystems, yet these assets are typically monitored and controlled through separate standards and protocols. The resulting heterogeneous information models and communication stacks hinder millisecond-level coordination, plug-and-play integration, and resilient operation. To address this gap, we [...] Read more.
Green buildings increasingly couple electrical, thermal, and hydrogen subsystems, yet these assets are typically monitored and controlled through separate standards and protocols. The resulting heterogeneous information models and communication stacks hinder millisecond-level coordination, plug-and-play integration, and resilient operation. To address this gap, we develop a unified information model and a cross-protocol real-time interaction mechanism based on extensions of IEC 61850. At the modeling level, we introduce new logical nodes and standardized data objects that describe electrical, thermal, and hydrogen devices in a single semantic space, supported by a global unit system and knowledge-graph-based semantic checking. At the communication level, we introduce a semantic gateway with adaptive mapping bridges IEC 61850 and legacy building protocols, while fast event messaging and 5G-enabled edge computing support deterministic low-latency control. The approach is validated on a digital-twin platform that couples an RTDS-based multi-energy system with a 5G test network. Experiments show device plug-and-play within 0.8 s, cross-protocol response-time differences below 50 ms, GOOSE latency under 5 ms, and critical-data success rates above 90% at a bit-error rate of 10−3. Under grid-fault scenarios, the proposed framework reduces voltage recovery time by about 60% and frequency deviation by about 70%, leading to more than 80% improvement in a composite resilience index compared with a conventional non-unified architecture. These results indicate that the framework provides a practical basis for interoperable, low-carbon, and resilient energy management in green buildings. Full article
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17 pages, 2752 KB  
Article
Short-Time Transient Thermal Behaviour in Textile Fabrics—The Dual Phase Approach
by Gilbert De Mey, Izabela Ciesielska-Wróbel, Maria Strąkowska, Bogusław Więcek, Carla Hertleer and Lieva Van Langenhove
Textiles 2025, 5(4), 66; https://doi.org/10.3390/textiles5040066 - 8 Dec 2025
Viewed by 230
Abstract
Short-time thermal exchange (0–20 s) between human skin and textile surfaces determines initial warm–cool sensations, which influences comfort perception. Classical Fourier models predicting a √t cannot fully describe this early transient phase, particularly for porous or heterogeneous materials such as fabrics. This study [...] Read more.
Short-time thermal exchange (0–20 s) between human skin and textile surfaces determines initial warm–cool sensations, which influences comfort perception. Classical Fourier models predicting a √t cannot fully describe this early transient phase, particularly for porous or heterogeneous materials such as fabrics. This study investigates the early and short-time temperature response of a fingertip to contact with eight woven and knitted fabrics of different compositions, densities, thermal resistances, and thicknesses, measured under controlled laboratory conditions using a fine-gauge thermocouple at the skin–fabric interface. Experimental temperature–time data, when converted to the Laplace domain, exhibited slopes corresponding to time-domain exponents of t, t¼, and occasionally t, all lower than the classical diffusion exponent of ½.The dual-phase lag (DPL) model was applied to interpret these deviations through two lag times—τq (heat flux) and τT (temperature gradient)—and their ratio Z = τT/τq, which controls the slope of the Laplace-domain response. DPL curves reproduced the observed exponents without additional empirical parameters. The results show that short-time heat transfer depends strongly on textile structure: higher thickness leads to slower transient responses (“warmer” feel), whereas denser fabrics promote faster equilibration (“cooler” feel). This dual-phase interpretation bridges physical heat transfer with tactile thermal perception, providing a predictive framework for the design of textiles with thermal properties. Full article
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23 pages, 12278 KB  
Article
Response and Reinforcement Mechanisms of Fiber-Reinforced Concrete Subjected to Dynamic Splitting Tensile Loading After High-Temperatures Exposure
by Jing Dong, Guiming Chen, Xiaojie Chen, Juan Du and Shuai Yang
Buildings 2025, 15(24), 4416; https://doi.org/10.3390/buildings15244416 - 6 Dec 2025
Viewed by 140
Abstract
Coupled high temperature and dynamic loading often leads to the complicated degradation of performance in industrial kilns, enclosures, or other concrete structures, which constitutes a serious hazard to the safety of concrete structure. To bridge this research gap, this study investigates not only [...] Read more.
Coupled high temperature and dynamic loading often leads to the complicated degradation of performance in industrial kilns, enclosures, or other concrete structures, which constitutes a serious hazard to the safety of concrete structure. To bridge this research gap, this study investigates not only the mechanical response but also the damage mechanisms of normal concrete (NC), basalt fiber-reinforced concrete (BFRC), and steel fiber-reinforced concrete (SFRC) under the coupled effects of high temperature and dynamic loading. Test specimens were conditioned for ambient conditions, 200 °C, 400 °C, and 600 °C, and underwent quasi-static and dynamic splitting tensile tests using the Split Hopkinson Pressure Bar (SHPB) with strain rates varying between 24 and 91 s−1. Significantly, the high-temperature-induced degradation of all types of concrete is remarkably suppressed by fibers, especially steel fibers. The best thermal degradability resistance was displayed by the SFRC with the highest remaining residual dynamic strength, peak strain, and energy dissipation, especially in the most severe (600 °C, 0.15 MPa) circumstances among these three types of materials. All materials revealed a clear strain rate strengthening effect. An empirical model, integrating the coupling effect of strain rate, temperature, and fiber type in DIF, was also developed, yielding better prediction capability than those already available. This reveals that the comprehensive performance of SFRC can meet structure requests, so it is suitable for applications involving steel fiber in environments characterized by high temperature and high strain rates. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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43 pages, 26581 KB  
Review
Advances in Computational Modeling and Machine Learning of Cellulosic Biopolymers: A Comprehensive Review
by Sharmi Mazumder, Mohammad Hossein Golbabaei and Ning Zhang
Biomimetics 2025, 10(12), 802; https://doi.org/10.3390/biomimetics10120802 - 1 Dec 2025
Viewed by 468
Abstract
The hierarchical structure and multifunctional properties of bio-based cellular materials, particularly cellulose, hemicellulose, and lignin, have attracted increasing attention and interest due to their sustainability and versatility. Recent advances in computational modeling and machine learning strategies have provided transformative insights into the molecular, [...] Read more.
The hierarchical structure and multifunctional properties of bio-based cellular materials, particularly cellulose, hemicellulose, and lignin, have attracted increasing attention and interest due to their sustainability and versatility. Recent advances in computational modeling and machine learning strategies have provided transformative insights into the molecular, mechanical, thermal, and electronic behaviors of these biopolymers. This review categorizes the conducted studies based on key material properties and discusses the computational methods utilized, including quantum mechanical approaches, atomistic and coarse-grained molecular dynamics, finite element modeling, and machine learning techniques. For each property, such as structural, mechanical, thermal, and electronic, we have analyzed the progress made in understanding inter- and intra-molecular interactions, deformation mechanisms, phase behavior, and functional performance. For instance, atomistic simulations have shown that cellulose nanocrystals exhibit a highly anisotropic elastic response, with axial elastic moduli ranging from approximately 100 to 200 GPa. Similarly, thermal transport studies have shown that the thermal conductivity along the chain axis (≈5.7 W m−1 K−1) is nearly an order of magnitude higher than that in the transverse direction (≈0.7 W m−1 K−1). In recent years, this research area has also experienced rapid advancement in data-driven methodologies, with the number of machine learning applications for biopolymer systems increasing more than fourfold over the past five years. By bridging multiscale modeling and data-driven approaches, this review aims to illustrate how these techniques can be integrated into a unified framework to accelerate the design and discovery of high-performance bioinspired materials. Eventually, we have discussed emerging opportunities in multiscale modeling and data-driven discovery to outline future directions for the design and application of high-performance bioinspired materials. This review aims to bridge the gap between molecular-level understanding and macroscopic functionality, thereby supporting the rational design of next-generation sustainable materials. Full article
(This article belongs to the Special Issue Advances in Biomaterials, Biocomposites and Biopolymers 2025)
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17 pages, 3709 KB  
Article
A Non-Intrusive DSMC-FEM Coupling Method for Two-Dimensional Conjugate Heat Transfer in Rarefied Hypersonic Conditions
by Ziqu Cao and Chengyu Ma
Aerospace 2025, 12(11), 1021; https://doi.org/10.3390/aerospace12111021 - 18 Nov 2025
Viewed by 361
Abstract
Accurate conjugate heat transfer (CHT) analysis is critical to the thermal management of hypersonic vehicles operating in rarefied environments, where non-equilibrium gas dynamics dominate. While numerous sophisticated CHT solvers exist for continuum flows, they are physically invalidated by rarefaction effects. This paper presents [...] Read more.
Accurate conjugate heat transfer (CHT) analysis is critical to the thermal management of hypersonic vehicles operating in rarefied environments, where non-equilibrium gas dynamics dominate. While numerous sophisticated CHT solvers exist for continuum flows, they are physically invalidated by rarefaction effects. This paper presents a novel partitioned coupling framework that bridges this methodological gap by utilizing the preCICE library to non-intrusively integrate the Direct Simulation Monte Carlo (DSMC) method, implemented in SPARTA, with the finite element method (FEM) via FEniCS for high-fidelity simulations of rarefied hypersonic CHT. The robustness and accuracy of this approach are validated through three test cases: a quasi-1D flat plate benchmark confirms the fundamental coupling mechanism against a reference finite difference solution; a 2D flat-nosed cylinder demonstrates the capability of the framework to handle highly non-uniform heat flux distributions and resolve the ensuing transient thermal response within the solid; finally, a standard cylinder case confirms the compatibility with curved geometries and its stability and accuracy in long-duration simulations. This work establishes a validated and accessible pathway for high-fidelity aerothermal analysis in rarefied gas dynamics, effectively decoupling the complexities of multi-physics implementation from the focus on fundamental physics. Full article
(This article belongs to the Section Aeronautics)
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15 pages, 2610 KB  
Article
Parameter Identification of SiC MOSFET Half-Bridge Converters Using a Multi-Objective Optimization Method
by Salvatore Monteleone, Luigi Danilo Tornello, Davide Patti, Giacomo Scelba, Maurizio Palesi, Enrico Russo, Mario Pulvirenti and Luciano Salvo
Electronics 2025, 14(22), 4458; https://doi.org/10.3390/electronics14224458 - 15 Nov 2025
Viewed by 290
Abstract
Silicon carbide (SiC) power converters are attracting increasing interest due to their significant advantages in terms of efficiency, switching speed, and greater temperature tolerance compared to traditional silicon-based converters. Tools to improve the design process, such as those to predict the switching behavior [...] Read more.
Silicon carbide (SiC) power converters are attracting increasing interest due to their significant advantages in terms of efficiency, switching speed, and greater temperature tolerance compared to traditional silicon-based converters. Tools to improve the design process, such as those to predict the switching behavior of silicon carbide-based power converters, can be of great help, e.g., in studying critical electrical/thermal stress in power devices. This work aims to present an effective multi-objective optimization method to identify the main parasitic parameters of a SiC half-bridge power converter related to the board layout and device packaging. This goal was achieved by minimizing the errors between the system responses carried out by the simulated power converter and the measurements collected from a limited number of experimental tests. The feasibility and effectiveness of the method are verified by tests performed on a 1200 V, 75 A, SiC half-bridge converter. Although this methodology has been validated for a specific converter topology, it can be extended to model more complex power converter structures. Full article
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26 pages, 3400 KB  
Article
Analysis of Retrofit Strategies of Mid-20th-Century Modern, Concrete Buildings
by Bernadett Csaszar, Richard O’Hegarty and Oliver Kinnane
Architecture 2025, 5(4), 108; https://doi.org/10.3390/architecture5040108 - 7 Nov 2025
Viewed by 736
Abstract
Reusing existing buildings is a valid response to the architectural challenge associated with addressing climate change and can aid the regeneration of the historic built environment. This demands sensitive architectural conservation strategies that improve thermal comfort, indoor environmental quality, and energy efficiency. In [...] Read more.
Reusing existing buildings is a valid response to the architectural challenge associated with addressing climate change and can aid the regeneration of the historic built environment. This demands sensitive architectural conservation strategies that improve thermal comfort, indoor environmental quality, and energy efficiency. In addition, energy retrofit solutions that balance performance improvements with the conservation of cultural and architectural values are needed to achieve higher performance while preserving cultural heritage, architectural features, and identity. Energy retrofits of post-war, mid-20th-century buildings pose particular challenges, including low ceiling heights, full-height windows, external decorative components, and other structural aspects, as these features hinder thermal upgrades. Concrete buildings from this period are frequently demolished due to limited guidance on effective retrofit methods. This study explores the most effective energy retrofit strategies for balancing energy efficiency with conservation requirements in such buildings, and assesses the risks associated with condensation and thermal bridging arising from internal insulation strategies. This paper examines internal insulation as a retrofit solution, where external insulation is not feasible. Internal wall insulation (IWI) reduces overall heat loss but concentrates thermal transfer at uninsulated junctions, thereby increasing the risk of condensation. In the simulated case, a relatively thin, short strip of slab insulation, combined with wall insulation, significantly reduced condensation and mould risk, suggesting a potential solution for mid-century building types. The analysis shows that applying insulation asymmetrically worsens conditions on the uninsulated side. Full-height window replacement, coupled with internal slab insulation, results in the most significant improvement; however, slab insulation alone can mitigate condensation risks where window replacement is not permitted. Findings highlight that partial insulation at balconies, parapets, and roof junctions is minimally effective, reinforcing the importance of integrated internal strategies for successful retrofits. Full article
(This article belongs to the Special Issue Strategies for Architectural Conservation and Adaptive Reuse)
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24 pages, 1553 KB  
Article
Year-Round Modeling of Evaporation and Substrate Temperature of Two Distinct Green Roof Systems
by Dominik Gößner
Urban Sci. 2025, 9(10), 396; https://doi.org/10.3390/urbansci9100396 - 30 Sep 2025
Viewed by 673
Abstract
This paper presents a novel model for the year-round simulation of evapotranspiration (ET) and substrate temperature on two fundamentally different extensive green roof types: a conventional drainage-based “Economy Roof” and a retention-optimized “Retention Roof” featuring capillary water redistribution. The main scope is to [...] Read more.
This paper presents a novel model for the year-round simulation of evapotranspiration (ET) and substrate temperature on two fundamentally different extensive green roof types: a conventional drainage-based “Economy Roof” and a retention-optimized “Retention Roof” featuring capillary water redistribution. The main scope is to bridge the gap in urban climate adaptation by providing a modeling tool that captures both hydrological and thermal functions of green roofs throughout all seasons, notably including periods with dormancy and low vegetation activity. A key novelty is the explicit and empirically validated integration of core physical processes—water storage layer coupling, explicit rainfall interception, and vegetation cover dynamics—with the latter strongly controlled by plant area index (PAI). The PAI, here quantified as the plant surface area per unit ground area using digital image analysis, directly determines interception capacity and vegetative transpiration rates within the model. This process-based representation enables a more realistic simulation of seasonal fluctuations and physiological plant responses, a feature often neglected in previous green roof models. The model, which can be fully executed without high computational power, was validated against comprehensive field measurements from a temperate climate, showing high predictive accuracy (R2 = 0.87 and percentage bias = −1% for ET on the Retention Roof; R2 = 0.91 and percentage bias = −8% for substrate temperature on the Economy Roof). Notably, the layer-specific coupling of vegetation, substrate, and water storage advances ecological realism compared to prior approaches. The results illustrate the model’s practical applicability for urban planners and researchers, offering a user-friendly and transparent tool for integrated assessments of green infrastructure within the context of climate-resilient city design. Full article
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25 pages, 957 KB  
Review
The Role of Probiotics in Healing Burns and Skin Wounds; An Integrative Approach in the Context of Regenerative Medicine
by Lenuta Ambrose, Ciprian Adrian Dinu, Gabriela Gurau, Nicoleta-Maricica Maftei, Madalina Nicoleta Matei, Maria-Andrada Hincu, Marius Radu and Mihaela-Cezarina Mehedinti
Life 2025, 15(9), 1434; https://doi.org/10.3390/life15091434 - 12 Sep 2025
Cited by 2 | Viewed by 2229
Abstract
In the context of thermal injury, local tissue integrity and systemic homeostasis are compromised, often resulting in delayed healing, infections, and disturbances of the skin and intestinal microbial balance. Despite several reviews addressing probiotics in wound healing, none has specifically focused on their [...] Read more.
In the context of thermal injury, local tissue integrity and systemic homeostasis are compromised, often resulting in delayed healing, infections, and disturbances of the skin and intestinal microbial balance. Despite several reviews addressing probiotics in wound healing, none has specifically focused on their role in thermal injuries and burn-associated pathophysiology. This review uniquely integrates evidence on the gut–skin axis, postbiotic innovations, and regenerative perspectives tailored to burn care. We conducted a critical synthesis of recent preclinical and clinical trials evaluating the use of probiotics and their derivatives to promote tissue regeneration following burn injury. Previous reviews have addressed probiotics in general wound repair, but the present synthesis advances the field by bridging mechanistic insights (immune modulation, angiogenesis, microbiome restoration) with translational evidence in burn patients, offering a framework for personalized regenerative approaches. Based on a structured review of the literature—including in vitro models, animal experiments, and randomized trials with topical, enteral, and systemic administration of probiotic—we identified four main mechanisms of action: modulation of the immune response by balancing cytokines and polarization of T lymphocytes; stimulation of tissue repair by increasing the proliferation of keratinocytes and fibroblasts, increased collagen synthesis, and induction of angiogenesis; direct antimicrobial activity against biofilms and multiresistant pathogens; and the restoration of eubiosis with the improvement of the function of epithelial barriers. While these findings endorse the adjunctive use of probiotics in burn management, large multicenter trials are required to standardize strains, dosages, and formulations before their routine clinical adoption. Full article
(This article belongs to the Section Medical Research)
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24 pages, 3760 KB  
Article
A Thermo-Photo-Ionic Crosslinked Gellan Gum Hydrogel with Gradient Biomechanic Modulation as a Neuromaterial for Peripheral Nerve Injury
by Sameera Khatib, Poornima Ramburrun and Yahya E. Choonara
Gels 2025, 11(9), 720; https://doi.org/10.3390/gels11090720 - 10 Sep 2025
Viewed by 779
Abstract
Gellan gum (GG) is a promising biomaterial due to its biocompatibility, tunable gelation, and modifiability. This study investigates the influence of triple crosslinking mechanisms—thermal gelation, UV-induced covalent crosslinking, and ionic crosslinking—on the mechanical and physicochemical properties of GG-based hydrogels, designed to function as [...] Read more.
Gellan gum (GG) is a promising biomaterial due to its biocompatibility, tunable gelation, and modifiability. This study investigates the influence of triple crosslinking mechanisms—thermal gelation, UV-induced covalent crosslinking, and ionic crosslinking—on the mechanical and physicochemical properties of GG-based hydrogels, designed to function as a neuromaterial with hierarchical neuro-architecture as a potential nerve substitute for peripheral nerve injury. Initial thermal gelation forms a physical network via double-helix junctions. Methacrylation introduces vinyl groups enabling UV crosslinking, while post-treatment with Mg2+ ions strengthens the network through ionic bridging with carboxylate groups. Plasticizers—glycerol and triethyl citrate—were incorporated to modulate chain mobility, network hydration, swelling behavior, and mechanical flexibility. Seven-day erosion studies showed that glycerol-containing hydrogels eroded 50–60% faster than those with triethyl citrate and up to 70% more than hydrogels without plasticizers, indicating increased hydrophilicity and matrix loosening. In contrast, triethyl citrate reduced erosion, likely due to tighter polymer chain interactions and reduced network porosity. Mechanical testing of 1% v/v methacrylated GG hydrogels revealed that 1.5% v/v triethyl citrate combined with UV curing (30–45 min) produced tensile strengths of 8.76–10.84 MPa. These findings underscore the synergistic effect of sequential crosslinking and plasticizer choice in tuning hydrogel mechanical properties for neuro application. The resulting hydrogels offer potential as a neuromaterial in peripheral nerve injury where gradient mechanical properties with hydration-responsive behavior are required. Full article
(This article belongs to the Special Issue Properties and Structure of Hydrogel-Related Materials (2nd Edition))
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28 pages, 58198 KB  
Article
Numerical Investigation of Ultra-Long Gravity Heat Pipe Systems for Geothermal Power Generation at Mount Meager
by Yutong Chai, Wenwen Cui, Ao Ren, Soheil Asgarpour and Shunde Yin
Mining 2025, 5(3), 55; https://doi.org/10.3390/mining5030055 - 9 Sep 2025
Viewed by 1622
Abstract
The Super-long Gravity Heat Pipe (SLGHP) is an efficient geothermal energy utilization technology that can transmit thermal energy by fully utilizing natural temperature differences without external energy input. This study focuses on the high-altitude geothermal environment of Mount Meager, Canada, and employs numerical [...] Read more.
The Super-long Gravity Heat Pipe (SLGHP) is an efficient geothermal energy utilization technology that can transmit thermal energy by fully utilizing natural temperature differences without external energy input. This study focuses on the high-altitude geothermal environment of Mount Meager, Canada, and employs numerical simulations and dynamic thermal analysis to systematically investigate the thermal transport performance of the SLGHP system under both steady-state and dynamic operating conditions. The study also examines the impact of various structural parameters on the system’s performance. Three-dimensional CFD simulations were conducted to analyze the effects of pipe diameter, length, filling ratio, working fluid selection, and pipe material on the heat transfer efficiency and heat flux distribution of the SLGHP. The results indicate that working fluids such as CO2 and NH3 significantly enhance the heat flux density, while increasing pipe diameter may reduce the amount of liquid retained in the condenser section, thereby affecting condensate return and thermal stability. Furthermore, dynamic thermal analysis using a three-node RC network model simulated the effects of diurnal temperature fluctuations and variations in the convective heat transfer coefficient in the condenser section on system thermal stability. The results show that the condenser heat flux can reach a peak of 5246 W/m2 during the day, while maintaining a range of 2200–2600 W/m2 at night, with the system exhibiting good thermal responsiveness and no significant lag or flow interruption. In addition, based on the thermal output of the SLGHP system and the integration with the Organic Rankine Cycle (ORC) system, the power generation potential analysis indicates that the system, with 100 heat pipes, can provide stable power generation of 50–60 kW. In contrast to previous SLGHP studies focused on generalized modeling, this work introduces a site-specific CFD–RC framework, quantifies structural sensitivity via heat flux indices, and bridges numerical performance with economic feasibility, offering actionable insights for high-altitude deployment. This system has promising practical applications, particularly for providing stable renewable power in remote and cold regions. Future research will focus on field experiments and system optimization to further improve system efficiency and economic viability. Full article
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21 pages, 7053 KB  
Article
Seasonal Regime Shifts and Warming Trends in the Universal Thermal Climate Index over the Italian and Iberian Peninsulas (1940–2024)
by Gabriel I. Cotlier and Juan Carlos Jimenez
Climate 2025, 13(9), 184; https://doi.org/10.3390/cli13090184 - 6 Sep 2025
Viewed by 1836
Abstract
This study investigates long-term changes in thermal comfort across the Italian and Iberian Peninsulas from 1940 to 2024, using the Universal Thermal Climate Index (UTCI) derived from ERA5-HEAT reanalysis. We apply a dual analytical framework combining structural break detection to identify regime shifts [...] Read more.
This study investigates long-term changes in thermal comfort across the Italian and Iberian Peninsulas from 1940 to 2024, using the Universal Thermal Climate Index (UTCI) derived from ERA5-HEAT reanalysis. We apply a dual analytical framework combining structural break detection to identify regime shifts and Sen’s slope estimation with confidence intervals to quantify monotonic trends. Results reveal pronounced seasonal asymmetries. Summer exhibits abrupt regime shifts in both regions: in 1980 for Italy (slope shifting from −0.039 °C/year before 1980 to +0.06 °C/year after) and 1978 for Iberia (from −0.054 °C/year to +0.050 °C/year). Winter, by contrast, shows no structural breaks but a persistent, spatially uniform warming trend of ~0.030–0.033 °C/year across the 1940–2024 period, consistent with a gradual erosion of cold stress. Transitional seasons display more nuanced responses. Spring reveals detectable breakpoints in 1987 for Italy (shifting from −0.028 °C/year to +0.027 °C/year) and 1986 for Iberia (from −0.047 °C/year to +0.024 °C/year), indicating the early acceleration of warming. Autumn shows a breakpoint in 1970 for Italy, with trends intensifying from +0.011 °C/year before to +0.052 °C/year after, while Iberia exhibits no clear breakpoint but a consistent positive slope. These findings highlight spring as an early-warning season, where warming acceleration first emerges, and autumn as a consolidating phase that extends summer-like heat into later months. Overall, the results demonstrate that Mediterranean thermal regimes evolve through both abrupt and gradual processes, with summer defined by non-linear regime shifts, winter by steady accumulation of warming, and spring and autumn by transitional dynamics that bridge these extremes. The methodological integration of breakpoint detection with Sen’s slope estimation provides a transferable framework for detecting climate regime transitions in other vulnerable regions under accelerated global warming. Full article
(This article belongs to the Special Issue The Importance of Long Climate Records (Second Edition))
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24 pages, 14126 KB  
Article
Stress-Barrier-Responsive Diverting Fracturing: Thermo-Uniform Fracture Control for CO2-Stimulated CBM Recovery
by Huaibin Zhen, Ersi Gao, Shuguang Li, Tengze Ge, Kai Wei, Yulong Liu and Ao Wang
Processes 2025, 13(9), 2855; https://doi.org/10.3390/pr13092855 - 5 Sep 2025
Viewed by 516
Abstract
Chinese coalbed methane (CBM) reservoirs exhibit characteristically low recovery rates due to adsorbed gas dominance and “three-low” properties (low permeability, low pressure, and low saturation). CO2 thermal drive (CTD) technology addresses this challenge by leveraging dual mechanisms—thermal desorption and displacement to enhance [...] Read more.
Chinese coalbed methane (CBM) reservoirs exhibit characteristically low recovery rates due to adsorbed gas dominance and “three-low” properties (low permeability, low pressure, and low saturation). CO2 thermal drive (CTD) technology addresses this challenge by leveraging dual mechanisms—thermal desorption and displacement to enhance production; however, its effectiveness necessitates uniform fracture networks for temperature field homogeneity—a requirement unmet by conventional long-fracture fracturing. To bridge this gap, a coupled seepage–heat–stress–fracture model was developed, and the temperature field evolution during CTD in coal under non-uniform fracture networks was determined. Integrating multi-cluster fracture propagation with stress barrier and intra-stage stress differential characteristics, a stress-barrier-responsive diverting fracturing technology meeting CTD requirements was established. Results demonstrate that high in situ stress and significant stress differentials induce asymmetric fracture propagation, generating detrimental CO2 channeling pathways and localized temperature cold islands that drastically reduce CTD efficiency. Further examination of multi-cluster fracture dynamics identifies stress shadow effects and intra-stage stress differentials as primary controlling factors. To overcome these constraints, an innovative fracture network uniformity control technique is proposed, leveraging synergistic interactions between diverting parameters and stress barriers through precise particle size gradation (16–18 mm targeting toe obstruction versus 19–21 mm sealing heel), optimized pumping displacements modulation (6 m3/min enhancing heel efficiency contrasted with 10 m3/min improving toe coverage), and calibrated diverting concentrations (34.6–46.2% ensuring uniform cluster intake). This methodology incorporates dynamic intra-stage adjustments where large-particle/low-rate combinations suppress toe flow in heel-dominant high-stress zones, small-particle/high-rate approaches control heel migration in toe-dominant high-stress zones, and elevated concentrations (57.7–69.2%) activate mid-cluster fractures in central high-stress zones—collectively establishing a tailored framework that facilitates precise flow regulation, enhances thermal conformance, and achieves dual thermal conduction and adsorption displacement objectives for CTD applications. Full article
(This article belongs to the Special Issue Coalbed Methane Development Process)
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15 pages, 3389 KB  
Article
Preparation, Performance Research and Field Application Practice of Temperature-Sensitive Lost Circulation Material for Shale Oil Wells
by Wenzhe Zhang, Jinsheng Sun, Feng Shen, Wei Li, Xianbin Huang, Kaihe Lv, Meichun Li, Shaofei Xue, Shiyu Wang and Hongmei Li
Polymers 2025, 17(17), 2395; https://doi.org/10.3390/polym17172395 - 2 Sep 2025
Cited by 1 | Viewed by 927
Abstract
Drilling fluid losses into formation voids are among the major issues that lead to increases in the costs and nonproductive time of operations. Lost circulation materials have been widely used to stop or mitigate losses. In most cases, the size of the loss [...] Read more.
Drilling fluid losses into formation voids are among the major issues that lead to increases in the costs and nonproductive time of operations. Lost circulation materials have been widely used to stop or mitigate losses. In most cases, the size of the loss zone is not known, making conventional lost circulation materials unsuitable for plugging the loss zone. In this study, novel temperature-sensitive LCM (TS-LCM) particles composed of diglycidyl ether of bisphenol A (DGEBA) and 4,4′-diaminodiphenyl methane were prepared. It is a thermal-response shape-memory polymer. The molecular structure was analyzed by Fourier transform infrared spectroscopy. The glass transition temperature (Tg) was tested by Different scanning calorimetry (DSC). The shape-memory properties were evaluated by a bend-recovery test instrument. The expansion and mechanical properties of particles were investigated under high temperature and high pressure. Fracture sealing testing apparatus was used to evaluate sealing performance. The mechanism of sealing fracture was discussed. Research results indicated that the Tg of the TS-LCM was 70.24 °C. The shape fixation ratio was more than 99% at room temperature, and the shape recovery ratio was 100% above the Tg. The particle was flaky before activation. It expanded to a cube shape, and the thickness increased when activated. The rate of particle size increase for D90 was more than 60% under 120 °C and 20 MPa. The activated TS-LCM particles had high crush strength. The expansion of the TS-LCM particles could self-adaptively bridge and seal the fracture without knowing the width. The addition of TS-LCM particles could seal the tapered slot with entrance widths of 2 mm, 3 mm and 4 mm without changing the lost circulation material formulation. The developed TS-LCM has good compatibility with local saltwater-based drilling fluid. In field tests in the Yan’an area of the Ordos Basin, 15 shale oil horizontal wells were plugged with excellent results. The equivalent circulating density of drilling fluid leakage increased by an average of 0.35 g/cm3, and the success rate of plugging malignant leakage increased from 32% to 82.5%. The drilling cycle was shortened by an average of 14.3%, and the effect of enhancing the pressure-bearing capacity of the well wall was significant. The prepared TS-LCM could cure fluid loss in a fractured formation efficiently. It has good prospects for promotion. Full article
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