Search Results (6,043)

The inefficient utilization of industrial by-product phosphogypsum, coupled with the increasing global demand for cooling, has spurred the development of sustainable radiative cooling materials. Compared with conventional cooling coatings that primarily rely on expensive synthetic materials or complex fabrication processes, this study provides a promising cost-effective and sustainable route for integrating industrial solid waste valorization with zero-energy cooling technologies. In this study, we fabricated a composite coating (β-HPG@CA/SiO₂@OTS) consisting of β-hemihydrate phosphogypsum (β-HPG), a derivative product of phosphogypsum, cellulose acetate (CA), SiO₂ particles and octadecyltrichlorosilane (OTS) by a facile combination of blade coating and spraying, which exhibited strong solar reflectivity (90.9%), high mid-infrared emissivity (98.7%) and satisfactory superhydrophobicity (157°). The as-prepared composite achieved an ambient temperature drop of 18.7 °C under direct sunlight during sunny weather, achieving a net cooling power of 92.23 W/m². Meanwhile, the composite coating exhibits excellent durability after prolonged immersion in strongly acidic and alkaline solutions, ultraviolet radiation and outdoor testing. Owing to its simple fabrication process and robust cooling performance, this coating shows promise for scalable production and practical outdoor applications, such as building envelopes and equipment enclosures. Full article

Internal thermal load fluctuations and variations in occupant density affect the performance of Hybrid Geothermal Heat Pump (HGHP) systems. Traditional control strategies cannot provide the rapid adjustments needed to operate efficiently in real time and can be inefficient, leading to increased energy consumption and reduced thermal comfort. A data-driven fuzzy logic control framework is developed in this paper to dynamically adjust the performance of an HGHP system in real time as a function of occupancy and environmental conditions (e.g., temperature and humidity differences). The controller analyzes input data related to real-time outdoor ambient conditions like temperature, humidity and occupied spaces; a real-time flow sensor attached to the occupants of the building (a count of the number of occupants currently in each occupied space); and the coefficient of performance (COP) of the HGHP system, and uses the analysis to generate a “smart” control decision for the following device types: variable speed drive (VSD), fan number, operating modes, system control and valve positions. The controller also controls the overall system. The model was developed and simulated in MATLAB Simulink^®, with realistic system parameters, and validated and calibrated using operational data from an HGHP system at a university, based on operating conditions. The simulation results indicate that our fuzzy controller achieves higher energy efficiency for thermal comfort than traditional thermostat-based controls, with COP improvements ranging from 7.36% to 11.76% and power consumption reductions between 4.13% and 8.55% across various occupancy scenarios. The improved COP also demonstrates the device’s responsiveness and effectiveness, even under frequent changes in occupancy patterns (dynamic occupancy), making it suitable for use in automated climate control systems in modern buildings. Full article

The Huoyanshan Cu-Zn volcanogenic massive sulfide (VMS) deposit, located in the North Qilian Orogenic Belt, China, is of significant economic importance. This study provides new constraints on the ore-forming processes through high-resolution in situ trace element and sulfur isotope analyses of pyrite and sphalerite using LA-(MC)-ICP-MS. Petrographic and geochemical investigations identified three distinct generations of pyrite (Py l to Py III). Early-stage Py I and Py II are characterized by high trace element contents (Au, As, Bi, Cu, Pb), elevated Co/Ni ratios (>1–10), and enriched δ³⁴S values (+4.98‰ to +7.47‰). These signatures indicate precipitation from high-temperature, reduced magmatic–hydrothermal fluids influenced by thermochemical sulfate reduction (TSR). Late-stage Py IIl exhibits markedly lower Co/Ni ratios (<0.1) and lighter δ³⁴S values (+3.72‰ to 3.89‰). This geochemical shift reflects a transition toward a cooler, more oxidized environment driven by the incursion and mixing of ambient seawater as the hydrothermal system waned. Trace element geochemistry of sphalerite reveals an average crystallization temperature of 265.8 °C (derived from the “GGIMFis” geothermometer), consistent with fluid inclusion data and representing a thermal “snapshot” of the waning hydrothermal stage. Systematic discriminant analysis using Ga/In, Ge/In, and Co-Ni-As systematics further confirms a strong magmatic–hydrothermal affiliation. Full article

A novel graphene-based nanomaterial, trade registered Hastalex^®, has been synthesised and investigated for its application as a 3D scaffold in surgical implantation. Hastalex is developed through the covalent bonding of amine-group-functionalised graphene oxide to the base chemical, poly(carbonate-urea)urethane. The material is under development for medical application including tendon, heart valve, and pelvic implant for prolapse surgery. For successful clinical translation, long-term rheological and chemical stability must be demonstrated and until now no systematic multi-year evaluation has been reported for graphene-poly(carbonate-urea)urethane nanocomposites. The material was synthesised in accordance with the patented formulation and evaluated at 0, 6, 12, and 24 months post-synthesis. Physicochemical properties were assessed using attenuated total reflectance Fourier-transform infrared spectroscopy, scanning electron microscope, contact angle measurements, thermogravimetric analysis, and mechanical analysis with tensile tests. Flow behaviour of Hastalex was evaluated using a rheometer to determine viscosity, shear stress response and impact of temperature changes and ageing on these factors. Hastalex exhibited non-Newtonian, shear-thinning behaviour consistent across all timepoints. Viscosity was found to increase progressively with ageing, attributed not to chemical degradation, but likely due to gradual solvent evaporation and densification of the polymer matrix during storage under ambient conditions. Rheological measurements across increasing temperature regimes revealed a heat-sensitive decrease in viscosity, followed by a reversal of changes beyond ~80 °C—likely due to enhanced solvent evaporation and chain reorganisation. This comprehensive material characterisation supports Hastalex as a promising candidate for bioengineering applications. Full article

In this study, composite silica-containing nanostructures were biosynthesized from residual rice husk through a fermentative process using Aspergillus niger at room temperature without calcination. The obtained nanostructures were initially characterized by UV–Vis spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FE-SEM) to determine their optical and structural properties compared with chemically synthesized silica. The results demonstrated the successful formation of composite silica-containing amorphous nanostructures under ambient conditions without the use of calcination or mineral acids. UV–Vis analysis revealed intense absorption in the deep ultraviolet region, attributed to electronic transitions associated with Si–O–Si bonds within the amorphous silica network. FTIR analysis enabled the identification of functional groups present on the material surface, providing direct evidence of the nanostructures’ chemical composition. Additionally, FE-SEM micrographs showed that the rice husk surface after biosynthesis exhibited a rough and porous texture with a morphology consistent with the formation of composite silica-containing amorphous nanostructures, in agreement with the characteristic Si–O–Si vibrational bands observed in the FTIR spectra and the strong ultraviolet absorption detected by UV–Vis analysis. Full article

With global warming and accelerated urbanization, building air-conditioning (AC) releases more heat into the environment, exacerbating the urban heat island (UHI) effects and increasing building cooling energy consumption. Existing research has limited quantification of the impact of air-conditioning anthropogenic heat (ACAH) on the cooling energy consumption of different types. This study aims to explore the distribution characteristics of ACAH and its impact on residential building energy consumption. Firstly, typical residential buildings in the Pearl River Delta region were selected as a case study. Field experiments were conducted to measure temperature and humidity at 0.5 m, 1 m, 2 m, and 3 m from the outdoor unit, alongside ambient temperature and wind speed. Three grid densities were applied to verify the CFD model, with a prediction error of less than 0.3 °C at 0.5 m under a medium grid. The simulated temperature at 1 m from the outdoor unit under calm wind conditions was compared with field measurements to reveal the horizontal and vertical distribution characteristics of ACAH. Secondly, the effects of different building shapes, ambient temperatures, and wind speeds on the spatial distribution of ACAH were investigated. Finally, EnergyPlus (V23.1.0) was employed as the building energy simulation software, with its microclimate coupling interface implemented via Python scripts to quantify cooling energy consumption variations across different building floors under ACAH influence. Results indicated that ACAH exhibits significant horizontal non-uniformity, exerting the greatest impact within a 0.5 m radius (affected air temperature 4.3 °C higher than ambient). Vertically, localized heat accumulation occurs in the building’s central area, with air temperature 3.5 °C higher than at the bottom. Furthermore, compared to fixed meteorological conditions, the cooling energy consumption difference across floors considering ACAH reaches approximately 7.8%. This study provides accurate meteorological boundary conditions for building energy assessment and supports microclimate management in residential areas. Full article

X ray photoelectron spectroscopy (XPS) is a key technique routinely employed for the chemical analysis of alloy surfaces, enabling precise nanoscale characterization of near surface elemental composition and chemical states. This review outlines the fundamental principles of XPS, typical data analysis workflows, and critical analytical considerations specific to alloy systems. Given the propensity for oxidation, multicomponent nature, and heterogeneous phase characteristics of alloys, standardized protocols are reviewed for sample preparation, binding energy calibration, peak fitting, quantitative analysis, and depth profiling. For conductive alloys, calibration using the Fermi edge or gold reference standards is specified, and the use of Auger parameters is highlighted to improve the reliability of chemical state identification. This article also systematically summarizes applications of XPS in corrosion protection, high temperature oxidation, surface modification, phase transformation, and failure analysis. It is emphasized that near surface chemical information must be validated in combination with bulk phase, microstructural, and electrochemical characterization to rationally establish relationships between surface chemistry and macroscopic performance. Finally, recent advances in near ambient pressure, in situ, high resolution, and intelligent XPS techniques are reviewed, providing a standardized reference and technical support for alloy research. Full article

This study investigates how the initial oxygen fraction in a confined space affects post-vent combustion, gas composition, and pressure hazards during thermal runaway (TR) of 58 Ah prismatic Li(Ni_0.8Co_0.1Mn_0.1)O₂ lithium-ion cells. Thermal abuse experiments were conducted in a 250 L sealed chamber under five initial oxygen fractions (20%, 15%, 10%, 5%, and 0% O₂), with synchronized measurements of cell temperature, vent-jet temperature, chamber pressure, voltage, and post-event gas composition. A first-vent event occurred reproducibly at a cell surface temperature of approximately 155 °C, followed by TR onset at about 170 °C. Although the onset temperatures were only weakly affected by ambient oxygen concentration, the post-vent hazard escalation depended strongly on oxygen availability. As the initial oxygen fraction increased from 0% to 20%, the peak vent-jet temperature increased from 353 °C to 1172 °C, and the peak chamber pressure rose from 90.7 kPa to 523.1 kPa. Gas chromatography showed that H₂, CO₂, CO, CH₄, and C₂H₄ were the dominant gaseous products. Lower oxygen fractions promoted retention of combustible species, whereas higher oxygen fractions enhanced oxidation and increased the CO₂/CO ratio. An oxygen-participation parameter, η, was introduced to quantify the fraction of initially available chamber oxygen consumed during post-vent oxidation. The increase in η was positively associated with oxygen-involved heat release and chamber overpressure. When the accessible oxygen fraction was limited to 10% or below, secondary combustion and pressure buildup were markedly suppressed, although a localized near-field thermal hazard remained significant around 10% O₂. These results provide quantitative guidance for enclosure inerting, vent management, and post-vent hazard mitigation in high-energy lithium-ion battery systems. Full article

To investigate the influence of external ambient temperature on the transmission characteristics of laser propagation in an internal channel, a simulation model of laser transmission within a closed channel is established in this study. The model comprehensively considers factors including gas density, refractive index distribution, and thermal deformation of optical components. Based on optical transmission theory, the model is used to calculate the beam drift characteristics and the variation in the Strehl ratio at different temperatures. The results indicate that ambient temperature has a significant impact on beam stability and quality. At low temperature (−30 °C), speckle structures appear in the laser spot, with minor drift along the X direction but obvious negative drift along the Y direction, mainly caused by the sinking of cold air driven by gravity and the refractive index gradient. The beam drift decreases initially with increasing temperature, reaches its minimum at around 10 °C, and then increases gradually as the temperature continues to rise. The Strehl ratio initially increases during the early stage of temperature rise, but diminishes in the high-temperature range due to intensified gas disturbances, enhanced thermal lensing effects, and aggravated mirror surface deformation. Full article

This study introduces a novel Quantum-Inspired Hybrid Bald Eagle-Ukari Algorithm with Reinforcement Learning (QI-HBEUA-RL) for comprehensive optimization of conical solar distillers equipped with sand-filled copper conical fins. The proposed algorithm synergistically combines quantum computing principles (superposition and entanglement), bio-inspired metaheuristics (Bald Eagle Search and Ukari Algorithm), and reinforcement learning mechanisms to achieve unprecedented optimization performance in complex thermal-hydraulic systems. The QI-HBEUA-RL framework employs quantum-encoded population representation, enabling simultaneous exploration of multiple solution states, while reinforcement learning dynamically adjusts algorithmic parameters based on search landscape characteristics and historical performance data. Experimental validation tested seven distiller configurations in El-Oued, Algeria, under controlled conditions (7.85 kWh/m²/day solar radiation, 42.2 °C ambient temperature). The optimal configuration of copper conical fins with 14 g sand at 0 cm spacing achieved: daily productivity of 7.75 L/m²/day (+61.46% improvement over conventional design), thermal efficiency of 61.9%, exergy efficiency of 4.02%, and economic payback period of 5.8 days. Comprehensive algorithm comparison against six state-of-the-art multi-objective optimizers (NSGA-II, MOEA/D, MOPSO, MOGWO, MOHHO) across 30 independent runs demonstrated statistically significant superiority (p < 0.001, Wilcoxon test). QI-HBEUA-RL achieved 7.42% improvement in hypervolume indicator, 29.35% reduction in inverted generational distance, and 19.49% better solution spacing. Generalization validation on seven benchmark problems (ZDT1-6, DTLZ2, DTLZ7) and three renewable energy applications confirmed algorithm robustness across diverse problem types. Three real-world case studies, remote village water supply (238:1 benefit–cost), industrial facility (100% energy reduction), and emergency relief (740× cost savings) validate practical implementation viability. This research advances solar thermal desalination technology and multi-objective optimization methodologies, providing validated solutions for sustainable freshwater production in water-scarce regions. Full article

Research on hydrogen production by chemical methods has focused on combining metals to carry out the hydrolysis reaction under ambient conditions. In particular, aluminum and lithium metals were considered, with lithium used at low concentrations in order to activate aluminum. Under these conditions, the metals can react with water to obtain the maximum hydrogen yield. The main objective of this work was to prepare the lithium−aluminum alloy by mechanical milling and its chemical reaction with water to produce hydrogen under laboratory conditions. A high–energy Spex mill was used for material preparation and the time scheduled for alloys preparation was relatively short. Several techniques were used for its characterization, such as X–ray diffraction, scanning electron microscopy, gas chromatography, and low-temperature physical adsorption. According to the results, two phases were produced during the milling process when using 5% lithium. The volume of hydrogen generated was measured using a graduated burette. Depending on the volume obtained, the aluminum reacted to generate hydrogen with an efficiency of 95.24%. No additives or catalysts were used in material synthesis or hydrogen production. According to these results, the hydrogen does not require any purification because it is clean hydrogen and can therefore be used directly in fuel cells. Full article

This paper presents a comparative evaluation of a wave union (WU) time-to-digital converter (TDC) implemented on two Microchip flash-based field-programmable gate arrays (FPGAs): the radiation-tolerant RTG4 (RT4G150-1CG) and the low-power SmartFusion2 (M2S150TS-1FCG1152). Both implementations use an identical VHDL architecture consisting of parallel tapped delay lines (TDLs) each with a WU pattern generator, edge-coded logic encoding, and real-time statistical bin width calibration. Single-shot precision (SSP), defined as the standard deviation of consecutive period measurements derived from calibrated timestamps, is evaluated across four independent input channels. Measurements are performed at five input frequencies (1, 2, 10, 20, and 40 MHz) and six ambient temperatures ranging from 20 °C to 60 °C. At a low input frequency, the RTG4 implementation achieves a mean SSP of 6.97 ps, while IGLOO2 yields 10.12 ps under identical conditions. As the input frequency increases, the SSP of both platforms decreases and converges to approximately 4.5 ps. However, at elevated temperatures, both devices experience observable degradation in SSP. To quantify thermal robustness, a thermal sensitivity coefficient (TSC) is introduced, defined as the rate of SSP variation with temperature. The results show that the same WU TDC core implemented on a space-graded FPGA exhibits improved thermal stability and reduced channel-to-channel variance compared to its equivalent on a commercial platform. Full article

Environmental temperature-induced metabolic changes in dams can be reflected by alterations in metabolomic and fatty acid profiles in colostrum. The colostrum from 13 Black Bengal (BB) dams was collected on the day of parturition at two consecutive parities during the hot conditions (HCs) of summer or rainy seasons and the cold conditions (CCs) of winter. The metabolomic and fatty acid profiles were analyzed using nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry, respectively. The results showed significantly higher sarcosine, tyrosine, citrate, succinate, galactose, acetylglucosamine, carnitine, choline, glycerophosphocholine, and trimethylamine N-oxide during CCs than HCs; potential discriminant metabolites according to VIP scores were sarcosine, succinate, and choline. Colostrum from CCs had significantly lower levels of saturated fatty acids (SFAs), including butyric acid (C4:0), myristic acid (C14:0), and pentadecanoic acid (C15:0), but higher omega-9 monounsaturated fatty acids (MUFAs), especially oleic acid (C18:1n9c), elaidic acid (C18:1n9t), and eicosenoic acid (C20:1n9), than in HC. Linoleic acid (C18:2n6c) and the omega 6/omega 3 PUFA ratio were higher during CCs than HCs. It is concluded that a metabolic shift for nutrient utilization occurs, from glucose during HCs toward fat during CCs, which may not be due to the diet but rather neurohumoral alterations occurring during temperature adaptation. Full article

Understanding pressure-induced isosymmetric phase transitions in molecular crystals requires consideration of both structural and thermodynamic factors, particularly in hydrogen-bonded systems. In this work, periodic density functional theory (DFT) calculations were employed to investigate the pressure-dependent behavior of L-serine and to elucidate the origin of its experimentally observed phase transition between Phase I and Phase IV. Geometry optimizations performed at ambient pressure and 8.8 GPa reproduce the compression of the crystal lattice and the pressure-driven stabilization of Phase IV. However, no spontaneous reorientation of the hydroxyl groups is observed, indicating that the transition is not accessible within a purely static framework. To further explore the stability of the system, a series of modified crystal structures with different hydroxyl group orientations was generated and analyzed, revealing a complex energy landscape at ambient conditions that becomes significantly simplified under compression. Phonon calculations within the quasi-harmonic approximation demonstrate that the experimentally observed Phase I structure is not stabilized by enthalpy but by vibrational entropy, whose contribution increases with temperature. These results show that the phase transition in L-serine is governed by an interplay between lattice energy, hydrogen-bond rearrangement, and vibrational effects, and highlight that an accurate description of polymorphic stability in such systems requires inclusion of both static and dynamic contributions. Full article

This study presents a combined process of sulfide precipitation followed by hydrogen peroxide leaching for rhenium recovery from copper smelting waste acid under ambient temperature and pressure. The process first removed copper through selective sulfide precipitation, then achieved co-precipitation of rhenium and arsenic to obtain a rhenium-rich precipitate. Subsequently, exploration of rhenium-containing precipitate leaching using H₂O₂ solution was conducted under isothermal conditions at 20 °C. The effects of H₂O₂ concentration, liquid-to-solid ratio, acidity, and leaching time rhenium extraction efficiency were examined systematically. The optimal leaching conditions were determined as: H₂O₂ concentration of 150 g/L, liquid-to-solid ratio of 5:1 mL/g, stirring speed of 350 r/min, and leaching time of 30 min. Under these conditions, the leaching conversions of rhenium and arsenic reached 96.0% and 93.8%, respectively. Through characterization of precipitate and leaching residue using ICP, SEM-EDS, XRD, and XPS analyses, the process and related reactions were elucidated. Results demonstrated that low-valence rhenium oxides and sulfides serve as the main reactive species during H₂O₂ leaching, whereas organic sulfur, high-valence oxides, and copper sulfide remained stable and resistant to leaching. Selective precipitation of copper effectively eliminated insoluble metal sulfides from rhenium-containing precipitates, thereby enabling efficient separation of rhenium under mild conditions. Full article