Search Results (17,678)

The energy sector is currently under enormous transition, moving from fossil fuels to renewable energies and integrating energy efficiency measures. This transition can hold opportunities for new and innovative energy systems. This study presents an energetic and economic assessment of an innovative tri-generation unit working with a two-phase thermodynamic cycle. The tri-generation unit is driven by heat and is capable of providing heat at lower level, cold, and electricity to end users. The use cases—residential, day-use offices, commercial retail, and manufacturing industry—are integrated in a dynamic simulation model, indicating the operation mode of the unit. The results show that the tri-generation unit is able to provide heat and cold with an Energy Utilization Factor of 35% to 68%, depending on the use case. Solar thermal has a limited to potential to supply the unit with heat, due to the high temperature of 180 °C and the required unit operation at nighttime. The economic comparison indicates that the driving heat must be as low as possible and that savings through self-consumption is most relevant. Full article

Cultural heritage systems play a crucial role in decoding human–environment interactions and social evolution. This study aims to reveal the spatial coupling characteristics of tangible and intangible cultural heritage in China, as well as the heterogeneity of their driving mechanisms. After quantifying heritage coupling at three geographic scales, we integrated a hierarchical Bayesian model with a hybrid causal inference framework to identify the correlations, causal effects, and heterogeneity of the driving factors. The empirical results indicate the following: (1) The coupling patterns exhibit scale dependence. The proportion of strongly coupled areas decreases from the prefecture-level scale to the provincial scale but increases at the cultural–geographical unit scale. This suggests that China’s cultural system has a cohesive effect that transcends administrative boundaries. (2) The hierarchical Bayesian model identifies the significant effects of mean annual temperature, population density, GDP–population interaction, transport–hydrological network interaction, and industrial structure. Effect strengths generally peak at the prefecture-level scale and decrease at the provincial scale. (3) Causal inference estimates the causal effects of mean annual temperature, transport–hydrological network interaction, mean annual precipitation, and water network density on coupling. (4) Heterogeneity tests reveal that the positive causal effect of transport–hydrological network interaction and the negative causal effect of mean annual precipitation are significant only in low-temperature regions. By integrating hierarchical modeling with causal verification, this study elucidates the mechanisms underlying heritage coupling. This provides a scientific basis for understanding the spatial patterns of cultural heritage systems and formulating differentiated conservation policies. Full article

The fluorescent dyes 9-aminoacridine (9-AA) and acridine orange (AO) are known mutagens that induce frameshift mutations in cells by intercalating between DNA bases. However, these chemicals can also affect other cellular components, such as proteins. In this study, we tested the ability of 9-AA and AO to induce heat shock in bacteria using the following methods: lux-biosensors based on Escherichia coli cells with the luxCDABE genes transcriptionally fused to heat shock-specific inducible promoters, RT-qPCR, and nanoDSF. We demonstrated that acridine dyes not only induce mutagenesis but also cause heat shock in bacterial cells. AO significantly reduced the melting temperature of proteins and strongly activated σ^E- and σ³²-dependent promoters, but not PluxC, which is activated by elevated temperatures via a different mechanism. In contrast, 9-AA weakly denatured the proteins and induced the σ^E-dependent promoter; however, it activated the σ³²-dependent promoters and PluxC, supporting the hypothesis that the σ³² heat shock response system is activated via hairpin RNA denaturation by 9-AA. The study on the application of lux-biosensors was hampered by the high general toxicity and luminescence shielding effect of AO, and RT-qPCR’s sensitivity was insufficient for detection of the response to 9-AA. Thus, methodologically, it is justified to conduct a comprehensive study of substances that cause heat shock or affect bioluminescence by both RT-qPCR and lux-biosensors. Full article

Proteins play an important role in living organisms, and, for most of them, the function depends on their structure. There are some proteins that have similar properties but different structures. An example of this is ice-binding proteins (IBPs), which have different structures but share the ability to bind to ice. Many organisms have evolved such proteins to help them survive in cold environments. Therefore, it is important to study the oligomeric state of the active form in solutions. The activity of IBP is related to the area of their ice-binding site. We have demonstrated the presence of oligomeric forms of protein in solution using multiple techniques, such as mass spectrometry, native gel electrophoresis, atomic force microscopy (AFM), isothermal titration calorimetry (ITC) and small-angle X-ray scattering (SAXS). It is noteworthy that, to date, there have been no reports of the oligomerization of ice-binding protein from Longhorn sculpin. Additionally, our findings suggest that larger molecules may influence the ability of proteins to bind to ice. In our study, the ice-binding protein forms elongated assemblies with limited intermonomer interfaces. The combination of SAXS and AFM data indicates a structure that combines compactness and flexibility and probably consists of four monomeric units. The employment of molecular modelling methodologies resulted in the attainment of a tetrameric complex that is in alignment with AFM data. Details of oligomers observed using the methods in our study emphasize the importance of different techniques that complement each other in resolving structural features. Additionally, we suggest that the protein particles, which were dispersed on the surface, exhibit softness or the form planar complexes with loose quaternary structures. It is conceivable that, depending on ionic strength and/or temperature, the various oligomeric forms of the ice-binding protein form thermodynamically more favorable complexes than their monomeric forms. Full article

We present the concept of an ultracold neutron (UCN) source with a superfluid He-4 (SF ${}^4$He) converter located in the thermal column of the WWR-K research reactor at the Institute of Nuclear Physics (INP) in Almaty, Kazakhstan. The conceptual design is based on the proposal of accumulating UCNs in the source and effectively transporting them to experimental setups. We propose to improve the UCN density in the source by separating the heat and UCN transport from the production volume and decreasing the temperature of the SF ${}^4$He converter to below about 1 K. To obtain operation temperatures below 1 K, we plan to use a He-3 pumping cryogenic system and minimize the thermal load on the UCN accumulation trap walls. Additional gain in the total number of accumulated UCNs can be achieved through the use of a material with a high critical velocity for the walls of the accumulation trap. The implementation of such a design critically depends on the availability of materials with specific UCN and cryogenic properties. This paper describes the conceptual design of the source, discusses its implementation methods and material requirements, and plans for material testing studies. Full article

The phenomenon of fast fashion has resulted in high yarn consumption and growing textile waste from both manufacturing and consumers. Rising environmental awareness and evolving legislation, including landfill restrictions, have prompted the search for sustainable recycling methods to manage textile end-of-life. This study investigates the mechanical recycling of polyamide 6.6 (PA66) yarn using a chain extender (Joncryl) and antioxidant (Irganox). Thermogravimetric analysis (TGA) confirmed that thermal stability in recycled PA66 was maintained compared to the original yarn, and the presence of Joncryl further enhanced this stability. Oxidative-onset temperature (OOT), measured by differential scanning calorimetry (DSC), supported these improvements. Gas chromatography–mass spectrometry (GC/MS) identified key degradation products, which were correlated with changes in the polymer matrix. Mechanical testing showed a 31% decrease in Young’s modulus after initial recycling, which was reversed with further processing. This behavior suggests the formation of shortened semi-crystalline chains and new linkages promoted by Joncryl. Viscosity and limiting viscosity number increased by up to 50%, depending on both additive concentrations. Overall, Joncryl and Irganox enhanced viscosity, mechanical strength, and notably thermal stability, confirming their suitability for recyclable textile-grade PA66 yarns. Full article

Chemical recycling is one of the most prominent techniques that enables monomer recovery for plastics like polyethylene terephthalate (PET), which ultimately reduces the dependency on virgin material inputs. In this study, 40 deep eutectic solvents (DESs) were pre-screened using COSMO-RS to identify the best solvent for chemical recycling of PET. Quantitative evaluation was performed based on activity coefficients (γ) to assess solute–solvent interactions. Qualitatively, the sigma profile and sigma potential were analyzed to understand the polarity and affinity of each DES component. This study experimentally validated the two top-performing DESs based on COSMO-RS output. The DES formed by combining thymol with phenol (Thy/Phe (1:2)) achieved 100% PET degradation and 94.5% terephthalic acid (TPA) recovery from post-consumer PET in just 25 min. The rapid dissolution of PET into molten state accelerated the hydrolysis reaction, leading to efficient monomer recovery. The second DES, tetrabutylammonium bromide/sulfolane (TBABr/Sulf (1:7)), attained 93.7% PET degradation and 94% TPA recovery. The PET-to-solvent ratio used in this study was 0.75, while the PET-to-DES ratio in the mixture was only 0.15, the lowest reported for DES-assisted hydrolysis to date. Characterization of the recycled TPA confirmed a purity level comparable to its virgin grade, as verified by FT−IR analysis. This study presents two important outcomes. First, the use of COSMO-RS for DES selection provides a strong rationale for solvent choice in targeted reactions and processes. Second, the use of appropriate DES in this study helps reduce key parameters associated with depolymerisation process, including reaction time, temperature, and catalyst consumption. Full article

Recent global efforts to produce lightweight electrified vehicles have motivated the push toward advanced lightweight materials which led to the creation of novel alloys optimized for use in high-pressure die casting (HPDC). HPDC enables the fabrication of near-net-shape automotive parts, significantly reducing or eliminating additional machining steps. A key feature of HPDC is the extremely fast cooling that forces the alloy to solidify within only a few seconds. Because of these rapid cooling conditions, it becomes essential to accurately evaluate the thermophysical behavior of newly designed lightweight alloys during severe quenching. Precisely quantifying these material properties is crucial for properly controlling HPDC operations and for building reliable numerical models that simulate filling and solidification. The thermophysical characteristics of such alloys vary markedly with temperature, especially when the material undergoes the fast solidification typical of HPDC. Therefore, understanding how these properties change with temperature during intense cooling becomes a critical requirement in alloy development. To address this need, a dedicated experimental system was designed to solidify molten metal samples under controlled and variable cooling conditions by applying multiple impinging water jets. An inverse heat-transfer algorithm was formulated to extract temperature-dependent thermal conductivity and diffusivity of the alloy as it solidifies under rapid cooling. To verify the reliability of both the inverse model and the measurements, experiments were performed using pure Tin, a reference material with well-documented thermophysical properties. The computed thermophysical properties of Tin were benchmarked against values reported in the literature and demonstrated reasonable consistency, with a maximum deviation of 13.6%. Full article

The growing demand for high-quality decorative polymer surfaces has increased interest in Out Mold Decoration (OMD), yet the combined influence of processing conditions and product geometry on film adhesion and deformation remains insufficiently defined. This study establishes an integrated framework that connects OMD process parameters with geometry-dependent deformation behavior using polycarbonate films printed with an ink grid. Adhesion and surface quality were evaluated using 2.5D specimens, while 3D models with varied fillet radii, slopes, and heights enabled quantitative assessment of grid-spacing evolution and thickness distribution. Results show that preheating smooths the film without improving adhesion, whereas increasing the forming environment temperature enhances both bonding and surface quality within the material’s thermal tolerance. Vacuum pressure strengthens film–substrate contact but requires moderation to prevent overstretching. An optimized condition of 100 °C preheating, 90 °C forming temperature, and 2.5 kg vacuum pressure provides a balanced performance. Geometric factors exert strong control over deformation, with small radii, steep slopes, and tall features producing greater strain and nonuniform thinning. These findings establish practical processing windows and geometry guidelines for achieving reliable OMD components that integrate high visual quality with stable adhesion performance. Full article

Heat is widely used to decontaminate livestock environments, yet performance varies with virus, surface, moisture, and organic load. We evaluated the effects of temperature (50, 60, 70 °C) and exposure time on the viability of 10 veterinary-relevant viruses (or surrogates) placed on four nonporous surfaces (plastic, rubber, aluminum, stainless steel) under dry or wet conditions, and in organic matrices (blood, wheat straw, complete feed). Infectivity was quantified by TCID₅₀ using independent duplicate experiments with duplicate titrations. Moist heat consistently outperformed dry heat: at 60–70 °C, all enveloped viruses, and most non-enveloped viruses were inactivated on surfaces within 5 min, while porcine parvovirus (PPV) remained the outlier, requiring ≥60 min. In contrast, dry heat allowed several viruses to persist for 24 h at 70 °C, underscoring that temperature alone is an unreliable predictor of rapid decontamination in the absence of humidity. Organic matrices modulated outcomes in a substrate- and virus-dependent manner, with some combinations accelerating inactivation and others prolonging survival to ≥180 min at ≥60 °C. These findings support matrix-aware, heat-assisted protocols for facilities and transport (e.g., 70 °C for ≥10 min under high humidity for most enveloped viruses), while recognizing exceptions such as PPV. The data provide actionable parameters to optimize thermo-assisted decontamination in veterinary systems. Full article

We investigated the tensile properties and deformation behavior at various temperatures of highly strong heat-elongated polypropylene (PP), in which stacks of crystalline lamellae are macroscopically arranged in the elongated direction and lamellae are connected by thin fibrils. The elastic modulus E′ and the αc-relaxation temperature for the onset of crystalline chain motion, obtained through dynamic mechanical analysis, were higher in the heat-elongated than the unelongated PP, indicating the suppression of crystalline chain motion. The heat-elongated PP deformed beyond the yield point at high temperatures above the αc-relaxation point, and it exhibited high tensile stress; e.g., the yield stress was 60 MPa at 120 °C, which was 7.5 times higher than that of the unelongated PP. Small-angle X-ray scattering intensity patterns changed from layered to diffuse, and DSC thermograms showed that melting peak position shifted to lower temperatures when stretching at small strains at various temperatures. The results suggest that lamella fragmentation occurs under small strains at various temperatures. Thus, the good high-temperature strength of the heat-elongated PP is due to the fragmentation of lamellae during small-strain stretching and the suppression of crystalline chain motion by thin crystalline fibrils connected to the lamellae. Full article

Thermal energy storage using latent heat storage materials represents a promising solution for stabilizing low-temperature energy systems; however, its effectiveness is limited by the low thermal conductivity of phase change materials (PCM), particularly salt hydrates such as sodium acetate trihydrate (SAT). The objective of this work is to analyze to what extent vertical gradation of a metallic gyroid structure can enhance heat transfer and temperature homogeneity in the PCM during charging. Time-dependent numerical simulations of conjugate heat transfer were performed for three gyroid variants differing in the orientation of pore gradation, modeling heat transfer between the flowing water, the aluminum gyroid structure, and the solid phase of SAT until the PCM reached a temperature of 58 °C. The results showed that the orientation of the gradation significantly affects both the heating dynamics and the quality of the temperature field. The variant with enlarged pores in the region of contact with the fluid and gradually decreasing pores toward the PCM achieved the shortest time to complete heating, the lowest temperature amplitude, and the highest degree of temperature homogeneity. This variant also exhibited the highest energetic efficiency, expressed as the ratio of transferred heat to pressure drop. The study demonstrates that deliberately designed gyroid gradation can substantially improve the performance of PCM composites without increasing the amount of material and represents a promising pathway for the development of advanced thermal storage systems. Full article

Geothermal springs are scattered worldwide and harbor thermophilic cyanobacteria, whose species distribution depends on extreme environmental conditions. The optical growth of cyanobacteria in hot springs and their metabolic diversity represent a source for possible biotechnological tools. In the current study, we isolated and characterized the cyanobacterial community of water samples from El Salado and Papallacta geothermal springs in Ecuador. We employed a culture-dependent as well as a polyphasic approach, which includes morphological examination by light microscopy, molecular analysis of 16S and 23S rRNA genes, and phylogenetic position using the maximum likelihood method. Notably, the morphological and molecular analyses complemented each other. Furthermore, we isolated eleven strains that belong to the taxa Tenebriella amphibia, Calothrix, Planktothricoides raciborskii, Nostoc, Fischerella muscicola, Leptolyngbya, Synechococcus, Komvophoron jovis, Chroococcales and Nostocacea. Both hot springs, whose temperature ranged between 45 and 54 °C, could harbor cosmopolitan and endemic cyanobacteria. Our study establishes a baseline for future efforts to exploit potential biotechnological tools bioprospected from these isolated microorganisms. Full article

Accurate suction control underpins thermo-hydro-mechanical (THM) characterization of unsaturated soils, yet conventional polyethylene-glycol (PEG) osmotic methods suffer from membrane degradation, polymer intrusion, and marked temperature sensitivity. This study evaluates a potassium-neutralized poly (acrylamide-co-acrylic acid) hydrogel (PP) as a high-suction osmotic medium for water-retention testing of compacted kaolin using a sealed cell with a grade-42 filter paper separator (no semi-permeable membrane). The water-activity–suction relation of PP was calibrated with a chilled-mirror hygrometer (WP4C) over the high-suction domain, and temperature effects were assessed between 20–30 °C. The PP imposed stable target suctions across the practical engineering range, with cross-validation to WP4C of R² ≈ 0.985 and RMSE ≈ 0.09 MPa, and exhibited modest thermal sensitivity (~2–3% per 10 °C). Mass–time records showed a two-regime equilibration (rapid first-day moisture loss then slowing to asymptote), with time to 95% equilibrium t₉₅ ≈ 3–7 days depending on suction, and equilibrium within ~2 weeks under a normalized mass change, ${\displaystyle \frac{1}{m}}\left|{\displaystyle \frac{∆m}{∆t}}\right|<{\displaystyle \frac{0.1\%}{24h}}$ criterion. The resulting kaolin water-retention curves are smooth soil moisture factor (SMF) reproducible, and exhibited minor wetting–drying hysteresis (~20–25% gap at matched suctions). Collectively, the results indicate that PP provides a practical, membrane-free (in the semi-permeable sense) and accurate means to control high-range suction for unsaturated soil testing, showing only modest suction variations within the tested 20–30 °C range, while mitigating long-standing PEG limitations and simplifying laboratory workflows. Full article

Textile dye effluents, particularly cationic dyes, pose a major environmental challenge, demanding efficient and sustainable adsorbent materials to remove harmful synthetic dyes. In this study, a reference thiourea–formaldehyde (TU/FA) composite and a series of thiourea–poly(acrylic acid)–formaldehyde (TU/PAA/FA) composites were synthesized and systematically characterized. The composites were prepared by varying the volume of poly(acrylic acid) PAA (from 1 to 7.5 mL) to assess how PAA incorporation influences morphology, crystallinity, surface chemistry, charge, and thermal stability. Analytical techniques including SEM, XRD, FT-IR, particle size distribution, zeta potential, and TGA/DTG revealed that increasing PAA content induced more porous and amorphous microstructures, intensified carbonyl absorption, reduced particle size (optimal at 2.5–5 mL PAA), and shifted the zeta potential from near-neutral to highly negative values (−37 to −41 mV). From TU/PAA/FA composite analysis, it was depicted that the TU/PAA-5/FA material has the better characteristics as a potential cationic dye absorbent. Thus, the adsorption performance of this composite toward crystal violet dye was subsequently investigated and compared to the reference material thiourea–formaldehyde (TU/FA). The TU/PAA-5/FA material exhibited the highest capacity (145 mg/g), nearly twice that of TU/FA (74 mg/g), due to the higher density of carboxylic groups facilitating electrostatic attraction. Adsorption was pH-dependent, maximized at pH 6, and decreased with temperature, confirming an exothermic process. Kinetic data followed a pseudo-second-order model (R² = 0.99), implying chemisorption as the rate-limiting step, while Langmuir isotherms (R² > 0.97) indicated monolayer adsorption. Thermodynamic analysis (ΔH° < 0, ΔS° < 0, ΔG° > 0) further supported an exothermic, non-spontaneous mechanism. Overall, the TU/PAA-5/FA composite combines enhanced structural stability with high adsorption efficiency, highlighting its potential as a promising, low-cost material for the removal of cationic dyes from textile effluents. Full article