Search Results (7,378)

Recycling end-of-life wind turbines poses a significant challenge due to the increasing number of turbines going out of use. After many years of operation, turbines lose their functional properties, generating a substantial amount of composite waste that requires efficient and environmentally friendly processing methods. Wind turbine blades, in particular, are a problematic component in the recycling process due to their complex material composition. They are primarily made of composites containing glass and carbon fibers embedded in polymer matrices such as epoxies and polyester resins. This study presents an innovative approach to analyzing and valorizing these composite wastes. The research methodology incorporates integrated processing and analysis techniques, including mechanical waste treatment using a novel compression milling process, instead of traditional knife mills, which reduces wear on the milling tools. Based on the differences in the structure and colors of the materials, 15 different kinds of samples named WT1-WT15 were distinguished from crushed wind turbines, enabling a detailed analysis of their physicochemical properties and the identification of the constituent components. Fourier transform infrared spectroscopy (FTIR) identified key functional groups, confirming the presence of thermoplastic polymers (PET, PE, and PP), epoxy and polyester resins, wood, and fillers such as glass fibers. Thermogravimetric analysis (TGA) provided insights into thermal stability, degradation behavior, and the heterogeneity of the samples, indicating a mix of organic and inorganic constituents. Differential scanning calorimetry (DSC) further characterized phase transitions in polymers, revealing variations in thermal properties among samples. The fractionation process was carried out using both wet and dry methods, allowing for a more effective separation of components. Based on the wet separation process, three fractions—GF1, GF2, and GF3—along with other components were obtained. For instance, in the case of the GF1 < 40 µm fraction, thermogravimetric analysis (TGA) revealed that the residual mass is as high as 89.7%, indicating a predominance of glass fibers. This result highlights the effectiveness of the proposed methods in facilitating the efficient recovery of high-value materials. Full article

Background: Thermal therapy represents a well-established therapeutic approach for chronic musculoskeletal and respiratory conditions. To date, no studies have investigated the clinical effects of treatment interruption in thermal medicine. We aimed to evaluate the clinical impact of COVID-19 lockdown-induced thermal therapy discontinuation through validated patient-reported outcomes. Methods: This single-center observational, retrospective study (March 2020–June 2024) evaluated 97 patients receiving standardized thermal therapy at Saturnia Thermal Springs. Treatment protocols included balneotherapy, mud therapy, and inhalation treatments in cycles of 12–15 sessions, with maintenance protocols every 4–6 months. Primary outcomes were assessed through VAS and SF-36 PCS, with EQ-5D and PSQI as secondary outcomes. Results: Significant clinical deterioration occurred during treatment interruption (p < 0.001) in 77.7% of patients. Recovery patterns were duration-dependent, with the 6–7-year cohort showing faster recovery (mean time to baseline: 2.8 months) compared to the 3–5-year cohort (4.6 months). Effect sizes were substantial across all outcomes (Cohen’s d > 1.0), with EQ-5D scores showing duration-dependent improvement (mean improvement in 6–7-year cohort: 0.27). Conclusions: Thermal therapy interruption precipitates quantifiable clinical deterioration, with recovery patterns significantly influenced by pre-existing treatment duration. These findings support the essential nature of treatment continuity in thermal therapy protocols. Full article

Extending sardine shelf life while maintaining their quality is challenging even with non-thermal technologies like high-pressure processing (HPP). This study examines the effects of HPP at 400 and 600 MPa for holding times of 1, 2.5, 5, and 10 min on fresh sardines during 14 days of cold storage. Physicochemical attributes, including texture, color, and volatile organic profiles, were assessed. Increasing both pressure and holding times resulted in increased levels of hardness, chewiness, and L* during storage. HPP-treated samples maintained lower a* values compared to the control ones by the end of the experiment. The volatile profile of HPP samples was significantly affected compared to control samples, which developed exclusively volatile oxidation compounds (hexanal and 2,4-hexadienal) by the end of the storage. Volatile groups such as aldehyde and ketone were slightly impacted by both storage and HPP treatments (i.e., pressure and holding time). Ketone levels were consistently lower in all treated samples, ranging from 25.3% to 33.6% at 400 MPa and 600 MPa, respectively, compared to the control samples, which had a ketone level of 40.5% on day 14. These findings indicate the potential of HPP in prolonging shelf life and preserving quality in the sardine market. Full article

In this study, an examination was conducted of the influence of iron tallate on the composition and properties of highly viscous oil from the Strelovskoye deposit in the Samara region under thermal–catalytic treatment (TCT). The research revealed that the dynamic viscosity of the oil following TCT at 300 °C, with a measurement temperature of 20 °C, decreased by a factor of 8 in comparison to the initial sample and nearly 4.5 times compared to the control sample at the 96-h mark. The most promising results in reducing the pour point temperature to 7 °C were identified following a 96-h TCT at 300 °C. This reduction was attributed to the decrease in paraffin content facilitated by the presence of the catalyst. According to the ICP-MS results, the extraction of the catalyst with the oil amounted to only 1%. This indicates that during the implementation of TCT within the reservoir, the catalyst is likely to adsorb onto the rock surfaces. Full article

Thermal modification improves the properties of wood, especially its stability and durability. We thermally treated spruce wood with the Thermowood process at three temperatures (160 °C, 180 °C, and 210 °C) and subjected it to accelerated aging in wet mode. We evaluated the chemical composition (wet chemistry, infrared spectroscopy), color, surface morphology, and wetting of the wood surface with water. Thermal treatment caused a significant decrease in hemicelluloses (up to 72.39% at a temperature of 210 °C), which initiated an increase in the content of more resistant wood components—cellulose and lignin. With accelerated aging, the hemicellulose content decreased by another 5%. The most significant differences between the infrared spectra of thermally modified wood before and after exposure to accelerated aging were in the absorption bands of lignin (1509 and 1596 cm⁻¹) and in the region of carbonyl groups between 1800 and 1630 cm⁻¹. Thermal treatment also caused a change in the color of the wood to dark brown; the overall color difference ΔE increased several times. The thermal-induced shortening of polysaccharide fibers and reduction in their width were even more manifested during accelerated aging. This work contains new knowledge about the properties critical for the reuse of thermally modified wood after accelerated aging, simulating the end of its life cycle. Full article

Increasing the flame retardancy of lignocellulosic materials such as Miscanthus × giganteus can effectively enable their wide use. This study examines the fireproofing process of Miscanthus particles using an eco-friendly process by grafting phytic acid and urea in aqueous solution. Miscanthus particles underwent a steam explosion step before being grafted. Fireproof binderless particle panels were manufactured from miscanthus particles with or without adding olive pomace by hot-pressing. The effect of the steam explosion and/or the flame-retardant treatment on the morphology, chemical composition and thermal stability of the particles, as well as the thermal stability of the panels, was investigated. The results showed that water impregnation followed by a steam explosion at 210 °C for 8 min resulted in particles that were rich in lignin and more homogeneous in size (length and width). Fireproof particles were produced with relatively low P and N contents. The flame retardancy of the binderless particle panels was significantly improved when using miscanthus particles treated with phytic acid and urea, as shown by a reduced heat release (HRR) and an increased time-to-ignition. However, the presence of olive pomace significantly decreased the flame retardancy of the panels. Binderless particle panels prepared from grafted miscanthus particles showed the best fire properties and are considered fireproof. Full article

Powder nickel-based superalloy is the key material for hot-end components such as turbine disks and gas engine disks in aeroengines, and its microstructure uniformity has an important influence on the disks’ service performance. However, thermomechanical treatments make it easy to produce abnormally large grains (ALGs) in powder superalloy disks. In order to investigate the relationship between the hot deformation conditions and ALGs of powder superalloys, isothermal compression experiments under various deformation conditions were carried out and a FE-CA method was constructed to investigate the ALGs formed by the limited recrystallization mechanism. The results indicate a close relationship between the ALGs formed after the supersolvus treatment of this alloy and the equivalent stress after thermal deformation, and the local dissolution of the γ′ phase in supersolvus heat treatment does not produce ALGs. Full article

High-pressure processing (HPP) is used as a non-thermal approach for controlling microbial viability. The purposes of this study were to (i) establish the decimal reduction times (D-values) for pathogenic bacteria during 350 MPa HPP treatment,; (ii) evaluate the impact of 350 MPa HPP on total plate count (TPC), yeasts and molds (YM), and lactic acid bacteria (LAB) in camel milk; (iii) investigate the behavior of several spoilage-causing bacteria during storage at 4 °C and 10 °C for up to 10 d post-HPP treatment; and (iv) assess the effect of HPP on the protein degradation of camel milk. The D-values for L. monocytogenes, E. coli O157:H7, and Salmonella spp. were 3.77 ± 0.36 min, 1.48 ± 0.08 min, and 2.10 ± 0.13 min, respectively. The HPP treatment decreased pathogenic microorganisms by up to 2 to 3 log cfu/mL (depending on treatment conditions). However, HPP reduced TPC, YM, and LAB by <1 log cfu/mL, regardless of the length of pressure exposure. HPP treatment, even at extended holding times, did not significantly alter either the proteolytic activity or casein micelle structure in camel milk. This study highlights HPP as a promising non-thermal technique for enhancing the microbiological safety of camel milk. Full article

Numerous studies have shown the potential effect of bioactive agents against weeds. In this study, we developed two binary formulations with nonanoic acid, citral, or thymoquinone as herbicides and evaluated their physicochemical properties. The presence of the bioactive compounds in the formulations was confirmed through FTIR spectroscopy. A dynamic light scattering study was conducted to characterize the emulsified formulations and the size and distribution of the aggregates. In addition, thermogravimetric analysis was performed to ensure the thermal stability of the formulations. The herbicidal activity against Amaranthus hybridus, Lolium multiflorum, and Brassica rapa weeds was evaluated, and each species showed different levels of sensitivity with half maximal inhibitory concentration doses from 0.07 to 5 mM. The binary formulations negatively affected the photosynthetic system reducing Fv/Fm values at 5 days after treatment. Lastly, the phytotoxic effect of the formulations was tested on wheat germination, and they did not inhibit plant germination and seedling growth at ≤5 mM after 14 days of application. The development of new formulations with natural compounds as bioactive ingredients would allow control of a wide spectrum of weeds through a multitarget-site effect. Full article

Thermal modification is an environmentally friendly process that does not utilize chemical agents to enhance the stability and durability of wood. The use of thermally modified wood results in a significantly extended lifespan compared with untreated wood, with minimal maintenance requirements, thereby reducing the carbon footprint. This study examines the impact of varying modification temperatures (160, 180, and 210 °C) on the lignin of spruce wood using the ThermoWood process and following the accelerated aging of thermally modified wood. Wet chemistry methods, including nitrobenzene oxidation (NBO), size exclusion chromatography (SEC), thermogravimetry (TG), differential thermogravimetry (DTG), and Fourier transform infrared spectroscopy (FTIR), were employed to investigate the alterations in lignin. At lower modification temperatures, the predominant reaction is the degradation of lignin, which results in a reduction in the molecular weight and an enhanced yield of NBO (vanillin and vanillic acid) products. At elevated temperatures, condensation and repolymerization reactions become the dominant processes, increasing these traits. The lignin content of aged wood is higher than that of thermally modified wood, which has a lower molecular weight and a lower decomposition temperature. The results demonstrate that lignin isolated from thermally modified wood at the end of its life cycle is a promising feedstock for carbon-based materials and the production of a variety of aromatic monomers, including phenols, aromatic aldehydes and acids, and benzene derivatives. Full article

The aim of this research is to investigate the phase composition and structural peculiarities of complex metamorphic manganese ores from Central Kazakhstan before and after sintering in the temperature range of 600–1200 °C in an air atmosphere. X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and optical microscopy were used to analyze changes in elemental and phase composition. In their initial state, according to XRF analysis, the Bogach ore was manganese-rich, with a manganese content of 60.77 wt.%, while the Zhaksy ore contained manganese (44.88 wt.%), silicon (20.85 wt.%), and iron (6.14 wt.%) as its main components. In the Bogach ore samples, manganese content increased from 60.77% to 65.7% as the sintering temperature rose to 1100 °C, while the hausmannite phase (Mn₃O₄) emerged as the dominant phase, comprising 95.77% of the crystalline component at 1200 °C. Conversely, the Zhaksy ore samples displayed a sharp increase in braunite-phase (Mn₇O₁₂Si) content, reaching 83.81% at 1100 °C, alongside significant quartz amorphization. The degree of crystallinity in Bogach ore peaked at 56.2% at 900 °C but declined at higher temperatures due to amorphous phase formation. A surface morphology analysis revealed the transformation of dense, non-uniform particles into porous, granular structures with pronounced recrystallization as the temperature increased. In the Bogach samples, sintering at 900 °C resulted in elongated, needle-like crystalline formations, while at 1200 °C, tetragonal crystals of hausmannite dominated, indicating significant grain growth and recrystallization. For Zhaksy samples, sintering at 1100 °C led to a porous morphology with interconnected grains and microvoids, reflecting enhanced braunite crystallization and quartz amorphization. These findings provide quantitative insights into optimizing manganese oxide phases for industrial applications, such as catalysts and pigments, and emphasize the impact of thermal treatment on phase stability and structural properties. This research contributes to the development of efficient processing technologies for medium-grade manganese ores, aligning with Kazakhstan’s strategic goals in sustainable resource utilization. Full article

Maraging steel is a high-performance material valued for its exceptional properties, making it ideal for demanding applications such as aerospace, tooling, and automotive industries, where high strength, toughness, and precision are required. These steels can be prepared by powder metallurgy techniques, which offer new processing possibilities. This paper introduces novel thermal powder pre-treatment and its impact on the final mechanical properties. Solid solution pre-treatment results in a modest improvement in strength (from 972 MPa to 1000 MPa), while the use of pre-aged powder achieves the highest strength (1316 MPa) and lowest ductility (2.6%). A self-composite material is created by mixing pre-treated powders with the same chemical composition but different properties. Such material was characterized by intermediate strength (1174 MPa) and ductility (3.1%). Although challenges such a porosity and oxidation were present, this approach allows for tuning of mechanical properties by mixing pre-treated powders, offering significant potential for advanced engineering applications. Full article

Xinjiang is a region of China that suffers severe energy resource loss and air pollution resulting from long-term coalfield fires in near-surface inclined coal seams. Beneath these fire areas, abandoned mined-out goaf is common. Accidents easily occur during the treatment of such fire areas owing to the instability of strata overlying the goaf. Here, we carried out non-destructive exploration of the goaf below a fire area using the airborne transient electromagnetic method, accurately identifying the locations and sizes of 21 goaf areas. We then established a stratigraphic model using the thermal-solid coupling function in UDEC software. Our simulations showed that under the combined action of high temperature generated by coal combustion and high pressure generated by fire-fighting machinery, the maximum displacement and vertical stress in strata overlying the goaf were 1.42 m and 36 MPa, respectively. Such large displacement and stress values inevitably lead to the destabilization of overlying strata via turning, sliding, and tipping, seriously threatening the safety of mining personnel and machinery. In the field, the rock layer above the goaf was first accurately blasted, and then fire extinguishing was carried out after the overlying rock had collapsed and compacted. Full article

In situ X-ray reciprocal space mapping was performed during the interval heating and cooling of InGaN/GaN quantum wells (QWs) grown via metal–organic vapor phase epitaxy (MOVPE). Our detailed in situ X-ray analysis enabled us to track changes in the peak intensities and radial and angular broadenings of the reflection. By simulating the radial diffraction profiles recorded during the thermal cycle treatment, we demonstrate the presence of indium concentration distributions (ICDs) in the different QWs of the heterostructure (1. QW, bottom, 2. QW, middle, and 3. QW, upper). During the heating process, we found that the homogenization of the QWs occurred in the temperature range of 850 °C to 920 °C, manifesting in a reduction in ICDs in the QWs. Furthermore, there is a critical temperature (T = 940 °C) at which the mean value of the indium concentration starts to decrease below 15% in 1. QW, indicating the initiation of decomposition in 1. QW. Moreover, further heating up to 1000 °C results in extended diffuse scattering along the angular direction of the diffraction spot, confirming the propagation of the decomposition and the formation of trapezoidal objects, which contain voids and amorphous materials (In-Ga). Heating InGaN QWs up to T = 1000 °C led to a simultaneous decrease in the indium content and ICDs. During the cooling phase, there was no significant variation in the indium concentrations in the different QWs but rather an increase in the defect area, which contributes to the amplification of diffuse scattering. A comparison of ex situ complementary high-resolution transmission microscopy (Ex-HRTEM) measurements performed at room temperature before and after the thermal cycle treatment provides proof of the formation of four different types of defects in the QWs, which result from the decomposition of 1. QW during the heating phase. This, in turn, has strongly influenced the intensity of the photoluminescence emission spectra without any detectable shift in the emission wavelength λ_MQWs. Full article

Oil extracted from tiger nut is a good, edible source owing to its richness in unsaturated fatty acids. This study investigated the effects of the refining processes on the flavor components of crude tiger nut oil by GC-MS and focused on the thermal stability of the refined oil under high-temperature conditions. Three different refining processes were evaluated: citric acid-assisted hydration degumming, alkali deacidification and bleaching. In the present study, the neutralization refining resulted in 11.67% losses. The refined oil had higher brightness and transparency. Moreover, 109 volatiles were identified, mainly including aldehydes, alcohols, pyrazines and furans, the characteristic flavor compounds of which present a fatty, fresh and nutty flavor. Hence, the refining processes have a significant effect on the flavor components of tiger nut oil, and the accumulated information can be helpful in increasing the tiger nut oil quality to meet the market value. The results of the thermal properties indicated the significant degradation of oleic acid and linoleic acid with prolonged heating, leading to increases in the acid value by 17 times and the peroxide value by 31 times after prolonged heating at 210 °C for 10 h compared with those without heating. When the refined tiger nut oil was heated at 210 °C for 4 h, the carbonyl value (62.6 meq/kg) exceeded the recommended value, and after heating for 8 h, the total polar compound percentages (50%, the instrument limit value) also exceeded the national standard. In order to extend the cooking heating time, it is necessary to appropriately decrease the heating temperature. This study provides a scientific reference for the frying of tiger nut oil in food and the high-temperature treatment of food containing tiger nut oil. Full article