This study introduces a novel equimolar PEG 200–PEG 400 binary base fluid designed to combine the advantages of both polymers, while MgO nanoparticles were incorporated at varying concentrations to further improve its thermal performance. The work presents a rigorous experimental characterization of the resulting nanocolloids, measuring and discussing density, isobaric heat capacity, and viscosity. Comparative analysis in terms of base fluids and nanocolloids reveals that nanoparticle integration increases density while inducing a moderate viscosity increase in low-concentration samples at ambient temperatures. Crucially, isobaric heat capacity exhibited a distinct sensitivity to both temperature and nanoparticle loading, prompting the development of new empirical correlation equations. Additionally, an investigation into viscosity hysteresis confirms that MgO nanoparticles significantly influence the fluid’s internal friction. These findings advance the development of PEG-based nanocolloids for advanced thermal management systems. The data analysis and proposed correlations suggest that the MgO-PEG interactions may influence the energy transport mechanisms within the liquid phase. Overall, the present experimental results may provide a useful basis for further investigating and potentially tailoring the thermal behavior of PEG-based nanocolloids for heat-transfer applications.
NiTiCu shape memory alloy wires are attractive candidates for compact actuator and smart-material applications, but their transformation behavior is highly sensitive to the applied heat-treatment route. SiC-susceptor-assisted microwave heat treatment has mainly been explored for porous or powder-based NiTi systems, and its applicability to wire-form NiTiCu alloys, evaluated through a direct comparison with conventional tube-furnace treatment under matched temperature conditions, has not been sufficiently addressed. In this study, commercial 0.5 mm-diameter NiTiCu wires were heat-treated at 450 °C for 30 and 60 min in a tube furnace and for 10 and 20 min in a microwave-assisted furnace, and the resulting phase transformation behavior, room-temperature phase structure, and cross-sectional microstructure were compared by DSC, XRD, and SEM/EDS. DSC results showed that only 10 min of microwave treatment (MW-10) raised the austenite finish temperature to 44.0 °C and the transformation enthalpy to 4.24 J g−1, values comparable to or exceeding those obtained after 60 min in the tube furnace (Af = 40.5 °C, ΔHA = 3.78 J g−1), indicating that a comparable transformation response can be achieved within a substantially shorter processing time. Extending the microwave treatment to 20 min (MW-20) reversed this trend: the transformation temperatures returned close to the as-received condition (Af = − 2.1 °C) and the enthalpy decreased to 2.14 J g−1, revealing a pronounced sensitivity of the microwave route to holding time. XRD and SEM/EDS analyses further showed that the room-temperature phase contribution (austenite- versus martensite-related reflections) varied with treatment condition, while the Ti-Ni-dominated local composition of the cross section was preserved after both routes. These findings indicate that short-duration SiC-susceptor-assisted microwave heat treatment may offer a time-efficient route for tailoring the transformation behavior of NiTiCu wires under the investigated conditions. Furthermore, this study provides a direct experimental comparison between microwave-assisted and conventional tube-furnace heat treatments for commercial NiTiCu wire samples under the same treatment temperature, thereby addressing a gap in the current literature.
This study aims to investigate the effects of flight conditions on the exergetic sustainability parameters of a micro-turbojet engine and to model these effects by utilizing machine learning approaches such as support vector regression (SVR), random forest (RF) and gradient boosting machine (GBM). It focuses on examining how the exergetic indices of the engine and its components vary under different flight conditions (Mach and altitude) and on evaluating their predictability as a function of these conditions. Within this scope, it was observed that the exergetic efficiency of the jet engine varies between 13.57
Given the low-cost and abundant availability of biomass fibers, they hold great application potential especially in architectural concrete. To exploit this potential in mitigating explosive spalling of concrete under high temperatures, a thorough understanding of their thermal stability and decomposition behavior is essential. This study employed thermogravimetry (TG) and one combined kinetic approach to elucidate the degradation mechanism, kinetics and thermodynamics of the target jute fiber. Non-isothermal thermogravimetric experiments were carried at 5, 10, 15 and 20 °C min-1 heating rates, and then the activation energy (Ea) distribution of overall pyrolysis process was calculated using Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, Starink, Friedman, Tang and Advanced iso-conversional methods. Kinetic analysis yields an average activation energy of 134.45 kJ mol-1 for the entire pyrolysis process, of which one specific pyrolysis stage within 0.1<α<0.78 was identified for jute fiber. Its appropriate reaction model D2 was further figured out by employing masterplots method. Subsequently, a linear relationship between Ea and lnA was obtained with full consideration of kinetic compensation effect, from which theoretical values of the reaction model function f(α) were derived. The optimal kinetic models for one main stage was reconstructed accordingly. Thermodynamic parameters (ΔH, ΔS, and ΔG) were also determined. All current findings provide essential data for evaluating the thermal stability of jute fiber in fire-resistant concrete applications.
This study investigates the mechanisms of viscous-flow sintering and nepheline formation in composite systems prepared from cadmium-coloured waste glass beads and clay-rich industrial residues. Finely ground glass cullet (60 mass
The well-known trade-off between engine emissions and performance is one of the primary obstacles to using waste cooking oil (WCO) biodiesel. WCO biodiesel frequently results in incomplete combustion and decreased efficiency because to its relatively high viscosity, poor cold flow, and improper atomization characteristics. The goal of this work was to boost the thermophysical characteristics and combustion behavior of WCO methyl ester by using metallic oxide nanoparticles as fuel additives. Methyl ester was converted from WCO via transesterification and blended with diesel oil at 20
Polyamide 66 (PA66) exhibits excellent properties and broad applications, but its flammability and flaming melt dripping pose serious fire hazards. Urea is nontoxic, biodegradable, inexpensive, and nitrogen-rich, making it a promising nitrogen source for phosphorus-nitrogen flame-retardant systems; however, the influence of its bonding mode with phosphorus-containing components remains unclear. Herein, a covalently coupled phosphorus-nitrogen flame retardant (DU) was synthesized from urea and [(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]succinic acid (DDP), a reactive phosphorus source. Physically blended and covalently coupled systems were compared regarding PA66 pyrolysis and charring. At 5 mass
Volatile organic compounds (VOCs) are critical air pollutants that pose significant risks to environmental quality and human health, necessitating accurate and intelligent monitoring systems. Conventional approaches often lack the computational capability required for reliable prediction under dynamic environmental conditions. This research proposes a Quantum Machine Learning-enabled AIoT sensor framework integrated with carbon nanocomposite-based sensing materials and a Harmonic Ranking mechanism to enhance predictive VOC air quality monitoring. Real-time data is acquired from the AIoT VOC Air Quality Sensor Dataset, comprising 1000 instances with 14 environmental and sensor response attributes. The sensing layer utilizes carbon nanocomposite-based sensors, which offer enhanced adsorption characteristics, improved sensitivity, and rapid response for VOC detection. The collected data undergo preprocessing, including noise filtering and normalization, followed by feature extraction using Principal Component Analysis (PCA) to identify dominant patterns influencing VOC concentration variability. Harmonic Ranking (HR) is incorporated to prioritize sensor data and enhance model stability by computing harmonic mean-based feature masses. It emphasizes critical sensor responses, reduces noise from less relevant attributes, and ensures robust feature fusion, thereby improving prediction accuracy and maintaining stable performance under dynamic environmental conditions. The optimized feature set is processed using an Artificial Protozoa Optimizer-driven Quantum Support Vector Regression Machine (APO-QSVRM), where APO performs efficient hyperparameter tuning and global optimization, while QSVRM leverages quantum-inspired feature mapping for nonlinear forecasting. The model is implemented in Python, and experimental results demonstrate enhanced predictive performance with RMSE (1.872), MAE (2.163), and MSE (1.548), along with stable inference across dynamic pollutant scenarios. The proposed framework provides a reliable and intelligent solution for next-generation VOC air quality monitoring systems.
Against the backdrop of accelerated urbanization, the planning and design of urban green environments have become particularly important. This article aims to explore the application of thermal space utilization and computer vision technology in urban green environment planning, especially in the application of data intelligence in landscape design. Based on computer vision for urban green impact processing, this study constructs a multi-scale fusion model to deeply analyze the urban heat island effect and its evolution, and extracts key influencing factors such as carbon emissions and temperature changes from the data. This provides a scientific basis for the rational utilization of urban thermal space. In the utilization of thermal energy space in urban green environment, the urban thermal spatial pattern and thermal comfort were studied, revealing the relationship between thermal energy distribution and urban form, providing empirical support for optimizing urban planning. Based on data intelligence in landscape design, the study utilized urban landscape dimension analysis technology to investigate the multiple effects of intelligent landscape design. The results indicate that adopting data-driven methods can significantly improve urban greening effects and residents’ thermal comfort, thereby improving urban environmental quality. The effective utilization of thermal energy space combined with computer vision technology provides new ideas and methods for urban green environment planning, promoting the process of urban sustainable development.
This study experimentally evaluated waste cooking oil (WCO) biodiesel–diesel blends in an unmodified single-cylinder direct injection diesel engine operated at 1500 rpm under no load and 1–5 kW load conditions. Diesel and B10–B50 were compared in terms of brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), and CO, HC, CO2, and NOx concentrations. Across 1–5 kW, diesel produced a mean BSFC of 310 g kW−1 h−1, while B20 showed the lowest value among the biodiesel blends at 320 g kW−1 h−1. Mean BTE decreased from 29.0
Natural convection in confined enclosures is central to many thermal systems. This study numerically examines the influence of an inclined magnetic field on natural convection and entropy generation in a trapezoidal cavity containing a heated wavy cylinder filled with Fe_3O_4 nanofluid. This research fills a notable gap in the literature by exploring the synergistic effects of a magnetic field orientation and nanoparticle concentration in governing heat transfer and thermodynamic irreversibility within a confined geometry by employing finite element simulations in COMSOL Multiphysics and validated against benchmark models. Convective transport and thermal behavior are characterized through streamlines, isotherms and average Nusselt numbers. The effects of Rayleigh number (10^3-10^5) , Hartmann number (0-20) , nanoparticle volume fraction (0-0.06) and Prandtl number (6.8377) are analyzed. The key findings indicate that increasing the Rayleigh number along with a higher corrugation number of a wavy cylinder results in enhanced velocity magnitudes of 66.95%, 65.67%, 66.56% and 66.84% , respectively. The inclusion of ferroparticles leads to the highest average Nusselt number of 17.8 . An increase in the Hartmann number (Ha) led to a 28.8% decline in the (Nu_ avg) at Ra=10^4 and a 19.7% decrease at Ra=10^5. A novel entropy analysis shows that the total irreversibility decreases by 18.5% and 35.8% with the Hartmann number and volume fraction, respectively, but increases by 92.4% with the Rayleigh number. These findings support the design of compact heat exchangers featuring trapezoidal cavities and corrugated surfaces frequently used to improved thermal performance in magnetically influenced cooling systems.
Boron-containing minerals have attracted significant attention in ceramic glaze systems due to their strong influence on melting behavior and glass structure. In this study, the effect of colemanite addition on opaque sanitaryware glazes was systematically investigated in terms of thermal behavior, phase evolution, microstructure, and functional and thermal properties. A standard industrial glaze composition was modified by incorporating 0.3–5 mass
The main focus of the current study is to explore the rate of heat transfer in MHD hybrid nanofluid (Cu–SiO2/H2O) Darcy–Forchheimer flow across the 3D rotating stretched sheet with dynamics of magnetic field, thermal radiation, shape of nanoparticles, suction, and convective boundary conditions. Currently, the hybrid nanofluid utilized for investigation is made up of copper (Cu) and silicon dioxide (SiO2) and water (H2O) as base fluid. The heat exchanger system, cooling system, different medical fields, and agriculture field are applications of hybrid nanofluid. The physical flow of problem is defined in the form of partial differential equations (PDEs). These systems of PDEs are converting in the system of ordinary differential equations (ODEs) through suitable similarity variables. These ODEs through bvp4c technique with package of MATLAB were graphically and numerically solved. When the higher of λ ,M,Fr, Po and S impact on the fluid velocity distribution along with both x-component are reduce but y- component are grow. The influences on the temperature profile raise with boosting the λ , M,Rd, n , and S. Then, when comparing the current findings to those of the previous, there is a strong correlation.
This study aims to investigate the relationship between heat transfer, thermal stresses, and temperature-dependent material degradation in cargo parachutes. The study evaluates how woven textile products used in parachute systems behave in relation to temperature. Considering that material degradation is a process that develops under combined mechanical and thermal effects, a theoretical temperature-dependent aging framework based on the Arrhenius relationship is presented. The study was conducted specifically with woven textiles designed at Erciyes University Aviation Application and Research Center (ERHAM). The temperature-dependent behavior of these specially designed woven fabrics was evaluated. The analyses were performed in the ANSYS Workbench environment using a one-way sequential Fluent–Mechanical FSI (Fluid–structure interaction) approach. The study lays the groundwork for a better understanding of the temperature-dependent mechanical strength of cargo parachutes before experimental data are obtained. In addition to providing a systematic framework for understanding the performance of parachute fabrics under thermal loads, the results obtained provide a roadmap for future experimental studies. This method is an important step in supporting cargo parachute design, durability evaluation, and reliability assessments.
The thermal stability of CL-20-based insensitive explosives has profound implications for their future applications. This study systematically investigates the thermal decomposition behavior, kinetic characteristics, and thermal stability of CL-20-based insensitive explosives by coupling thermal analysis results with the Semenov model. The results indicate that due to the synergistic effect of ammonium perchlorate (AP) with CL-20 and aluminum powder, the composite system exhibits a singular exothermic behavior. The activation energies calculated using the Kissinger method and Flynn–Wall–Ozawa (FWO) method are 159.32 kJ mol−1 and 163.82 kJ mol−1, respectively, which are lower than the 207±18 kJ mol−1 for pure CL-20. Due to the significant kinetic compensation effect between lnA and E, the activation energy calculated based on adiabatic acceleration calorimetry (ARC) is 408.23 kJ mol−1, which is significantly higher than that calculated by differential scanning calorimetry (DSC). Based on DSC and ARC, the self-accelerating decomposition temperatures (TSADT) are determined to be 178.86 °C and 175.45 °C, respectively, which are very close to the actual thermal runaway temperature of the sample (190 °C), with relative deviations of 5.86
7H-Benz[de]anthracen-7-one, commonly known as benzanthrone (BA), is a fluorescent dye, which is recognised for its strong luminescence and high photostability. A wide range of BA-based derivatives has attracted increasing attention in material research due to potential application possibilities in forensic science, anti-counterfeiting technologies, optical materials, biotechnology, material labelling, as well as in the textile and polymer industries. While recent studies have primarily focused on the synthesis and characterisation of the molecular structure and optical properties of various BA-based derivatives, information regarding their thermal stability remains limited, which is essential for future industrial processing steps. Therefore, the present work focuses for the first time on the systematic characterisation of thermal processes and their influence on the structure and luminescence behaviour of BA and its derivatives with various functional groups using a combination of several physico-chemical analytical techniques. The melting points and decomposition temperatures of commercially available BA and 3-bromobenzanthrone (3-BrBA), along with synthesised 3-nitrobenzanthrone (3-NO2BA) and 3-aminobenzanthrone (3-NH2BA), were determined using thermogravimetry-differential scanning calorimetry (TG-DSC). The gaseous compounds, which were released during heating up to 900 °C in different atmospheres, were analysed using Fourier transform infrared (FTIR) spectroscopy. Subsequently, thermal annealing was performed at selected temperatures near or higher than the determined melting points of these BA-based compounds in different atmospheres (air, nitrogen and vacuum). Characterisation of these compounds before and after annealing included analysis of structure using attenuated total reflectance (ATR) – FTIR spectroscopy and evaluation of luminescence behaviour using fluorescence spectroscopy. The obtained ATR-FTIR spectra showed no significant changes in the structure of BA and its derivatives after annealing up to complete thermal decomposition, regardless of the applied atmosphere. However, in the cases of 3-NH2BA and 3-NO2BA, annealing in air led to visible differences in luminescence behaviour, which suggests the formation of more emissive compounds through thermal decomposition and oxidation processes.
This study investigates the effect of heating rate on the oxidation behavior of waste tungsten carbide (WC) using non-isothermal thermogravimetric analysis (TGA). Tungsten oxide formation through high-temperature oxidation was systematically analyzed at different heating rates (5, 10, 20, and 40 °C min−1) under an air atmosphere. The kinetic parameters were evaluated using four model-free iso-conversional methods—Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Starink together with the model-fitting Coats–Redfern (CR) approach. The calculated average activation energy values were found to be 231.1, 229.1, and 229.5 kJ mol−1 for FWO, KAS, and Starink methods, respectively, showing good agreement among the models. Reaction mechanism analysis revealed a transition from reaction-controlled kinetics at low heating rates (5 °C min−1) to diffusion-controlled behavior at higher heating rates (20–40 °C min−1). Structural and morphological characterization was performed using XRD, Raman spectroscopy, SEM, and EDS analyses. The results confirmed the formation of tungsten oxide phases after oxidation. The positive activation enthalpy indicates that energy input is required to reach the transition state, confirming the kinetically controlled nature of the oxidation process. The findings provide useful insights for the recycling and thermal processing of waste tungsten carbide materials.
Polymorphism and its extended form, pseudopolymorphism, significantly affect the physicochemical properties, thermal stability, and potential pharmaceutical performance of biologically active compounds. Oxicams are a class of nonsteroidal anti-inflammatory drugs (NSAIDs) widely used in clinical practice; however, they are associated with a range of adverse effects. Consequently, there is ongoing interest in developing new derivatives with improved safety profiles. Moreover, owing to their structural flexibility and ability to form intramolecular hydrogen bonds and tautomeric structures, oxicam derivatives represent an interesting class of compounds exhibiting diverse solid-state behavior. In this work, a new arylpiperazine oxicam derivative was obtained as two distinct crystalline forms and characterized using spectroscopic methods (1H NMR, 13C NMR, ESI–MS, and FTIR) together with X-ray powder diffraction (XRPD). The results confirmed that the two forms differ in crystal packing and intermolecular interactions despite retaining the same molecular structure. Their thermal behavior was investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results demonstrated that form I is the thermodynamically stable form, whereas form II is a pseudopolymorphic form incorporating ethanol molecules during crystallization. These findings provide insights into the relationship between solvation and crystal packing in novel oxicam derivatives and contribute to a better understanding of solid-state transformations in pharmaceutically relevant molecules.
This study evaluated the use of the CALPRESDAT SN 20132 scanning microcalorimeter for studying aqueous surfactant systems under slow temperature-scanning conditions. Pure water and an aqueous sodium dodecyl sulfate (SDS) solution were used as model systems to determine whether the instrument could distinguish differences in their calorimetric signals. The measurements showed a stable instrumental baseline and revealed additional thermal effects in the SDS solution within the temperature range of approximately 295–300 K that were absent from the corresponding water measurement. These observations demonstrate that the instrument can distinguish small thermal differences between aqueous systems of different composition. Because only one SDS concentration was investigated and no complementary experimental techniques were used, the observed thermal effects cannot be interpreted unambiguously. The results provide a basis for future studies involving a wider range of surfactant types, concentrations, independent control of thermodynamic variables and complementary physicochemical techniques.
In the context of the global energy crisis and the Carbon Peak and Carbon Neutrality Goals, it has become an urgent task to seek efficient and environmentally friendly refrigeration technology. As a refrigeration scheme that can be driven by low-grade heat sources such as solar energy and industrial waste heat, ejector refrigeration technology has shown enormous potential due to its simple structure, reliable operation, environmental protection, and energy saving. This paper systematically reviews the recent research and development of ejector refrigeration technology in ejector and refrigerant in recent years, and combs the recent research progress of different ejector refrigeration systems from different classification methods. Finally, it points out the challenges faced by the current research and looks forward to the development direction of future research. This review aims to provide readers with an overview of recent theoretical and experimental studies on ejector refrigeration systems and help readers understand and sort out relevant research progress.
