Search Results (52)

Ice accretion alters the airfoil profile of the unmanned aerial vehicle (UAV), degrading the aerodynamic performance and potentially triggering safety incidents. The computation of droplet impingement characteristics is the primary task for ice accretion analysis and the design of anti-icing/de-icing systems for UAVs. To address the disadvantages of the conventional Eulerian method and the Lagrangian method, a streamline-based Eulerian method is established to obtain the droplet impingement characteristics. It only solves the momentum equation to derive the velocity field, eliminating the computational load of the droplet continuity equation. Droplet streamlines are generated via backward integration in the droplet velocity field, allowing impingement characteristics to be calculated. In this scheme, the droplet collection efficiency is computed without the predetermination of droplet release locations or tracking a large number of droplet trajectories. The proposed method is applied to obtain the droplet collection efficiencies in the cases of an NACA0012 airfoil, a two-dimensional (2D) cylinder, an MS (1)-0317 airfoil, and an RG-15 airfoil. The results show good agreement with the data in the literature; therefore, the feasibility and effectiveness of this streamline-based Eulerian method are confirmed. This work can provide a reference for ice accretion analysis and anti-icing/de-icing system design for UAVs. Full article

Transmission line icing poses a significant natural disaster threat to power grid security. This paper systematically reviews recent advances in the understanding of icing mechanisms, intelligent detection, and prevention technologies, while providing perspectives on future development directions. In mechanistic research, although a multi-physics coupling framework has been established, characterization of dynamic evolution over complex terrain and coupled physical mechanisms remains inadequate. Detection technology is undergoing a paradigm shift from traditional contact measurements to non-contact intelligent perception. Visual systems based on UAVs and fixed platforms have achieved breakthroughs in ice recognition and thickness retrieval, yet their performance remains constrained by image quality, data scale, and edge computing capabilities. Anti-/de-icing technologies have evolved into an integrated system combining active intervention and passive defense: DC de-icing (particularly MMC-based topologies) has become the mainstream active solution for high-voltage lines due to its high efficiency and low energy consumption; superhydrophobic coatings, photothermal functional coatings, and expanded-diameter conductors show promising potential but face challenges in durability, environmental adaptability, and costs. Future development relies on the deep integration of mechanistic research, intelligent perception, and active prevention technologies. Through multidisciplinary innovation, key technologies such as digital twins, photo-electro-thermal collaborative response systems, and intelligent self-healing materials will be advanced, with the ultimate goal of comprehensively enhancing power grid resilience under extreme climate conditions. Full article

Background/Objectives: Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple organ systems, characterized by remissions and relapses. Musculoskeletal involvement occurs in up to 95% of patients and may present as the initial symptom in 50%. Such involvement is often subclinical, without obvious joint or tendon inflammation. Musculoskeletal ultrasound (US) has proven valuable for detecting pathological changes in joints and periarticular structures, including in SLE patients, and early detection, particularly in subclinical stages, supports optimal therapy, monitoring, and improved prognosis. This study aimed to determine the frequency of new clinical manifestations in patients with previously confirmed clinical and subclinical musculoskeletal inflammation after 2 and 5 years, and to evaluate associations with sex, age, BMI, smoking status, ESR, CRP, SLEDAI-2K, complement components C3 and C4, anti-dsDNA antibodies concentrations, and prior treatment. Methods: The study included 34 SLE patients with clinical and 22 with subclinical musculoskeletal inflammation, confirmed at baseline by history, examination, and US. Follow-up at 2 and 5 years recorded new clinical manifestations. Correlations with patient characteristics were assessed to identify predictors. Results: New clinical manifestations occurred in 34% of patients at 2 years and 48% at 5 years, most commonly cutaneous, musculoskeletal, and hematological. Summary analysis identified female sex, lower BMI, and lower baseline SLEDAI-2K scores as the strongest predictors. In the subclinical group, female sex, smoking, and lower SLEDAI-2K scores were predictive, while in the clinical group, female sex, lower SLEDAI-2K scores, lower ESR, and higher anti-ds DNA levels were associated with new manifestations. Conclusions: Female sex, lower BMI, and lower baseline SLEDAI-2K scores are key predictors of new clinical manifestations in SLE patients, highlighting the importance of early detection and individualized monitoring, particularly in patients with subclinical musculoskeletal inflammation. Full article

A series of experiments were carried out to evaluate different anti-/de-icing approaches for a Pitot probe. Using the Iowa State University Icing Research Tunnel (ISU-IRT), this study compared the performance of a traditional electrically heated system with that of a hybrid concept combining reduced-power electrical heating and a superhydrophobic surface (SHS) coating. The effectiveness and energy efficiency of both methods were assessed. High-speed imaging was employed to capture the transient ice accretion and removal phenomena on the probe model under a representative glaze icing condition, while infrared thermography provided surface temperature distributions to characterize the unsteady heat transfer behavior during the protection process. Results indicated that, due to the placement of the internal resistive heating elements, ice deposits on the total pressure tube were easier to shed than those on the supporting structure. Relative to the conventional approach of maintaining a fully heated probe, the hybrid technique achieved comparable anti-/de-icing performance with substantially reduced power requirements—showing up to ~50% savings during anti-icing operation and approximately 30% lower energy use with 24% faster removal during de-icing. These findings suggest that the hybrid strategy is a promising alternative for improving Pitot probe icing protection. Full article

In-flight icing presents a critical safety hazard for unmanned aerial vehicles (UAVs), resulting in ice accumulation on propeller surfaces that compromise UAV aerodynamic performance and operational integrity. While hybrid anti-/de-icing systems (i.e., combining active heating with passive superhydrophobic coatings) have been developed recently to efficiently address this challenge, conventional active heating sub-systems utilized in the hybrid anti-/de-icing systems face significant limitations when applied to curved geometries of UAV propeller blades. This necessitates the development of innovative self-heating superhydrophobic coatings that can conform perfectly to complex surface topographies. Carbon-based electrothermal coatings, particularly those incorporating graphite and carbon nanotubes, represent a promising approach for ice mitigation applications. This study presents a comprehensive experimental investigation into the development and optimization of a novel self-heating carbon nanotube (CNT)-based superhydrophobic coating specifically designed for UAV icing mitigation. The coating’s anti-/de-icing efficacy was evaluated through a comprehensive experimental campaign conducted on a rotating UAV propeller under typical glaze icing conditions within an advanced icing research tunnel facility. The durability of the coating was also examined in a rain erosion test rig under the continuous high-speed impingement of water droplets. Experimental results demonstrate the successful application of the proposed sprayable self-heating superhydrophobic coating in UAV icing mitigation, providing valuable insights into the viability of CNT-based electrothermal coatings for practical UAV icing protection. This work contributes to the advancement of icing protection technologies for un-manned aerial systems operating in adverse weather conditions. Full article

To investigate how sand erosion impacts the anti-icing performance of wind turbine blade surfaces, this study experimentally examines the individual and interactive effects of four key factors—the freezing temperature, separation temperature, surface roughness of eroded blade coatings, and loading rate on ice adhesion properties.The results from single-factor analyses reveal that the ice adhesion strength increases linearly with decreasing separation temperature. A more nuanced relationship emerges when considering the freezing temperature relative to the separation temperature: when the freezing temperature exceeds the separation temperature, the adhesion strength rises linearly as the separation temperature drops; conversely, when the freezing temperature is lower than the separation temperature, the adhesion strength decreases linearly with falling separation temperature. Higher loading rates correlate with reduced ice adhesion, while increased surface roughness induced by sand erosion leads to greater adhesion strength. Orthogonal array testing demonstrates the hierarchy of these factors’ influence on post-erosion ice adhesion, as follows: separation temperature > loading rate > freezing temperature > surface roughness of sand-eroded coatings. Notably, the separation temperature and loading rate exert the most significant effects. Furthermore, a regression equation for ice adhesion strength is established based on orthogonal test results, which can effectively predict ice adhesion strength under untested parameter combinations. These findings provide critical foundational data and a reliable theoretical tool to inform the development and optimization of practical de-icing systems in engineering applications. Full article

Icing represents a significant hazard to the flight safety of unmanned aerial vehicles (UAVs), particularly affecting critical aerodynamic surfaces such as air intakes, wings, and empennages. While conventional adhesive electrothermal de-icing systems are straightforward to operate, they present safety concerns, including a 15–25% increase in system weight, elevated anti-/de-icing power consumption, and the risk of interlayer interface delamination. To address the objectives of reducing weight and power consumption, this study introduces an innovative electrothermal–structural–durability co-design strategy. This approach successfully led to the development of a glass fiber-reinforced polymer (GFRP) component that integrates anti-icing functionality with structural load-bearing capacity, achieved through an embedded hot-pressing process. A stress-damage cohesive zone model was utilized to accurately quantify the threshold of mechanical performance degradation under electrothermal cycling conditions, elucidating the evolution of interfacial stress and the mechanism underlying interlayer failure. Experimental data indicate that this novel component significantly enhances heating performance compared to traditional designs. Specifically, the heating rate increased by approximately 202%, electrothermal efficiency improved by about 13.8% at −30 °C, and interlayer shear strength was enhanced by approximately 30.5%. This research offers essential technical support for the structural optimization, strength assessment, and service life prediction of UAV anti-icing and de-icing systems in the aerospace field. Full article

Ice accumulation poses a significant hazard to aviation safety, particularly in cold weather conditions, as it can compromise aerodynamic performance, increase structural weight, and diminish lift, occasionally resulting in severe stall incidents. At present, such risks are managed through the use of energy-demanding active ice protection systems (IPSs), which operate either by inhibiting ice formation (anti-icing) or by removing existing ice (de-icing). Nonetheless, in the context of future sustainable aviation, there is a pressing need to develop IPSs with lower energy requirements. A promising approach involves hybrid IPSs that integrate conventional active systems with passive superhydrophobic or icephobic surface treatments, which are capable of preventing, delaying, or minimizing ice buildup. These systems offer the potential to substantially decrease the energy consumption and consequently the CO₂ emissions. Furthermore, in accordance with FAA regulations, active IPSs are not permitted to operate during takeoff and initial flight stages to prevent any reduction in engine thrust. These two reasons emphasize the critical importance of developing efficient coatings that, on the one hand, promote the mobility of water droplets, hereby preventing ice formation, as achieved by superhydrophobic surfaces, and on the other hand, facilitate ice detachment, as required for icephobic performance. In this context, the primary objective of the present work is to emphasize the icephobic properties of two superhydrophobic coatings. To achieve this, an extensive characterization is first conducted, including wettability, Surface Free Energy (SFE), and surface roughness, to confirm their superhydrophobic nature. This is followed by an assessment of their icephobic performance, specifically in terms of ice adhesion strength, with comparisons made against a commercial aeronautical coating. The results revealed a significant reduction in both the wettability and SFE of the developed coatings compared to the reference, along with a marked decrease in ice adhesion strength, thereby demonstrating their icephobic properties. Future activities will focus on the combination of coatings with active IPS in order to assess the energy efficiency under extensive icing conditions where both superhydrophobic and icephobic properties are required. Full article

Background/Objectives: Red blood cell (RBC) alloimmunization is a significant challenge in transfusion medicine, particularly among transfusion-dependent patients, such as those with thalassemia. It arises from the production of antibodies against non-self RBC antigens and can lead to complications like hemolytic transfusion reactions. This study aimed to evaluate the prevalence, specificity, and clinical implications of RBC alloimmunization at the University Clinical Center of Serbia (UCCS), emphasizing transfusion-dependent populations. Methods: This retrospective study analyzed 27,530 transfusion records at UCCS between January 2023 and January 2024. Pre-transfusion testing included ABO and RhD typing, irregular antibody screening, and crossmatching. Data from 630 patients with positive antibody screening were reviewed. Alloantibody specificity was determined using indirect antiglobulin tests and advanced phenotyping methods. Results: Among 27,530 patients, 630 (2.29%) tested positive for irregular antibodies, predominantly males (57.14%) with a mean age of 49.6 years. Alloantibodies were detected in 70.47% of cases, most commonly targeting Rh (53.35%) and Kell (17.15%) systems. Anti-E (27.93%) and anti-D (18.02%) were the most frequent antibodies. Multiple alloantibodies were identified in 18.41% of patients, posing challenges for blood compatibility. In a total of 495 patients with thalassemia, antibodies were found in 9.69%. Alloimmunization was significantly associated with higher numbers of transfusions and pregnancies (p < 0.05). Conclusions: Our findings indicate that alloimmunization is predominantly associated with Rh and Kell antigens, suggesting that implementing targeted antigen matching may reduce the frequency of alloimmunization. While our study does not directly assess the impact of genotypic matching, the prior literature supports its role in enhancing transfusion safety, particularly for high-risk populations like thalassemia patients. Full article

Electrothermal anti-/de-icing systems are widely used in aircraft, and the structures of these systems generally consist of multiple layers laminated together. In service, laminated structures are prone to structural deformation and delamination, which can significantly affect heat conduction. Therefore, it is essential to study the temperature field of these electrically heated anti-icing structures during operation and analyse the impact of delamination damage on the temperature distribution. In this thesis, a dynamic multiphysical field study of an electric heating anti-icing structure is conducted using a thermal expansion layer-by-layer/3D solid element method. By studying the electric heating process of composite plates experiencing pre-positioned delamination, the thermal expansion layer-by-layer/3D solid element method considers the thermal convection boundary conditions as well as a constant heat source. In addition, to considering the influences of the geometric shape and delamination damage, we apply the thermal expansion layer-by-layer/3D solid element method to the electric heating anti-icing process of aerofoil structures using a coordinate transformation matrix. The calculations show that when delamination damage is located above the heating layer, the maximum temperature of the structure reaches 450 °C at 50 s, which severely affects the normal functioning of the structure. Additionally, the surface temperature of the anti-icing system decreases to the ambient temperature at the delamination. In contrast, delamination damage located below the heating layer has a minimal effect on the surface temperature distribution. Moreover, the damage caused by multiple types of damage is greater than that caused by a single type of damage. Full article

Ice accumulation on wind turbine blades poses a significant challenge to turbine performance and safety, and these issues have led to extensive research on developing effective anti-icing methods. Polymer-based icephobic coatings have emerged as promising solutions, given their passive nature and low energy requirements. However, developing effective icephobic coatings is a complex task. In addition to anti-icing properties, factors such as mechanical strength, durability, and resistance to UV, weathering, and rain erosion must be carefully considered to ensure these coatings withstand the harsh conditions faced by wind turbines. The main challenge in coating engineering is mastering the chemistry behind these coatings, as it determines their performance. This review provides a comprehensive analysis of the suitability of current icephobic coatings for wind turbine applications, emphasizing their alignment with present industrial standards and the underlying coating chemistry. Unlike previous works, which primarily focus on the mechanical aspects of icephobicity, this review highlights the critical yet underexplored role of chemical composition and explores recent advancements in polymer-based icephobic coatings. Additionally, earlier studies largely neglect the specific standards required for industrial applications on wind turbines. By demonstrating that no existing coating fully meets all necessary criteria, this work underscores both the urgency of developing icephobic coatings with improved durability and the pressing need to establish robust, application-specific standards for wind turbines. The review also combines insights from cutting-edge research on icephobic coatings that are coupled with active de-icing methods, known as the hybrid approach. By organizing and summarizing these innovations, the review aims to accelerate the development of reliable and efficient wind energy systems to pave the way for a cleaner and more sustainable future. Full article

Background/objectives: The outcome of refractory/relapsed systemic Anaplastic Large Cell Lymphoma (R/R-sALCL), especially for anaplastic lymphoma kinase-1 (ALK-1)-negative disease, remains dismal even after autologous hematopoietic stem cell transplantation (AHSCT). The intensification of both salvage and conditioning regimens, without increasing the toxicity, could improve the outcome of AHSCT in R/R-sALCL. Methods: Based on the successful experience of the incorporation of antiD20 monoclonal antibodies in the treatment of B-Cell Lymphomas, we designed a salvage and conditioning regimen incorporating the antiCD30-conjugated antibody (Brentuximab Vedotin, BV) to standard chemotherapy regimens, and we describe herein the clinical course of a patient with AKL-ve, R/R-sALCL, who received salvage regimen BV + DHAP, followed by AHSCT with preparative regimen consisted of BV plus standard BEAM. Results: The novel regimen was well tolerated, and no severe adverse effects were noticed. The engraftment was prompt and successful. The patient remained in complete metabolic remission for almost 12 months post-transplant. Conclusions: The proposed treatment approach, which combines antiCD30-conjugated antibody with standard salvage and conditioning regimens, demonstrated a completely acceptable toxicity with promising efficacy. Full article

The thermodynamics of black holes (BHs) and their corrections have become a hot topic in the study of gravitational physics, with significant progress made in recent decades. In this paper, we study the thermodynamics and corrections of spherically symmetric BHs in models $f\left(R\right)=R+\alpha R^2$ and $f\left(R\right)=R+2\gamma \sqrt{R+8\Lambda }$ under the $f\left(R\right)$ theory, which includes the electrodynamic field and the cosmological constant. Considering thermal fluctuations around equilibrium states, we find that, for both f(R) models, the corrected entropy is meaningful in the case of a negative cosmological constant (anti-de Sitter–RN spacetime) with $\Lambda =-1$. It is shown that when the BHs’ horizon radius is small, thermal fluctuations have a more significant effect on the corrected entropy. Using the corrected entropy, we derive expressions for the relevant corrected thermodynamic quantities (such as Helmholtz free energy, internal energy, Gibbs free energy, and specific heat) and calculate the effects of the correction terms. The results indicate that the corrections to Helmholtz free energy and Gibbs free energy, caused by thermal fluctuations, are remarkable for small BHs. In addition, we explore the stability of BHs using specific heat. The study reveals that the corrected BH thermodynamics exhibit locally stable for both models, and corrected systems undergo a Hawking–Page phase transition. Considering the requirement on the non-negative volume of BHs, we also investigate the constraint on the EH radius of BHs. Full article

Ice accretion on aircrafts due to atmospheric conditions is still a relevant research topic, especially in the case of Unmanned Aerial Vehicles (UAVs), due to their smaller size and the relative underdevelopment of ice protection systems (anti-icing and de-icing) for these aircraft. For the research and development of these systems, it is necessary to assess their performance in icing wind tunnels (IWTs), which are generally high-cost facilities. This article describes the design and building process of a new IWT for testing fixed-wing UAVs, aimed at cost reduction and restricted to an existing cold climate chamber of limited size. The designed IWT is an open-circuit type with two corners, a test section size of 0.40 m × 0.27 m and speed up to 70 m/s. The design process employs widely used and proven semi-empirical formulas, supported by detailed calculations using Computational Fluid Dynamics (CFD) tools, to achieve a test section core of useful quality and avoid flow separation. Theoretical limits with respect to a usable droplet size and Liquid Water Content (LWC) are calculated, and the test section core is estimated. The design process followed proves to be a very good approach to the design and aerodynamic optimisation of a low-cost IWT. Full article

The “bare runway” principle aims to ensure passenger and employee safety by making runways more usable during winter conditions, allowing for easier removal of contaminants like snow and ice. Maintaining runway operations in winter is essential, but it involves considerable cost and environmental impacts. Greater knowledge about the de-icing and anti-icing performance of runway de-icing products (RDPs) optimizes operations. The ice melting test, as per the AS6170 standard, gauges the rate at which an RDP dissolves an ice mass to determine RDP effectiveness. Here, we introduce a novel integrated methodology for assessing RDP-related ice melting. We combine laboratory-based procedures with infrared thermography and Raman spectroscopy to monitor the condition of RDPs placed on ice. The plateau of maximum efficiency, marked by the most significant Raman peak intensity, corresponds to the peak minimum temperature, indicating optimal RDP performance. Beyond this point, RDP efficacy declines, and the system temperature, including melted contaminants and RDP, approaches ambient temperature. Effective RDP performance persists when the ambient temperature exceeds the mixture’s freezing point; otherwise, a freezing risk remains. The initial phases of RDP–ice contact involve exothermic reactions that generate brine, followed by heat exchange with surrounding ice to encourage melting. The final phase is complete ice melt, leaving only brine with reduced heat exchange on the surface. By quantifying these thermal and chemical changes, we gain a deeper understanding of RDP-related ice melting, and a more robust assessment can be provided to airports using RDPs. Full article