Search Results (11,933)

The article presents the research findings on a collection of ceramic crucibles excavated at the Koksharovka-1 hillfort, known as one of the most significant archaeological sites of the Medieval epoch (7th–13th centuries) in the Russian Far East. This study represents an investigation of melting crucibles as a distinct category of metalworking ceramics discovered in the research area. The study is based on an integrated approach combining traditional archaeological analysis with physicochemical methods, including scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), X-ray fluorescence spectroscopy (XRF), Raman spectroscopy, electron probe microanalysis (EPMA), and computed microtomography (micro-CT). The research found that the morphological and technological properties of the crucibles were consistent with their function as containers for metal heat treatment. Traces of copper-based alloys as well as gold and silver processing were detected as a result of the crucible examination. For the first time, archaeological evidence of silver and gold metalworking in the Russian Far East during the Medieval epoch has been obtained. Full article

The present study is situated within the broader research context of optimizing the use of C60 steel in industrial applications, with a particular emphasis on enhancing durability and fatigue resistance, two critical factors in the field. C60 steel is renowned for its exceptional combination of strength and hardness. However, a critical evaluation is necessary to ascertain the impact of thermal and thermochemical treatments on its performance under fatigue conditions. An investigation was conducted into the crack formation process and the early stages of fatigue in C60 steel. The effects of heat treatment (hardening and tempering) were compared with those of thermochemical treatments (oxidation) on the steel’s microstructure. Furthermore, the performance of C60 steel under fatigue conditions was evaluated based on the applied treatments. The insights gained from this research can optimize the use of this steel in industries requiring high resistance and durability. The study’s methodology encompassed the execution of fatigue tests on a four-point bending machine, a procedure that was meticulously employed to ascertain the onset of microcracking. The C60 steel samples were processed in accordance with SR ISO 1099:2017, entitled “Fatigue testing. Axial load method”. To ensure consistency and comparability of results, the samples were fabricated from the same material charge and machined under identical conditions. A total of 26 samples were utilized, with 13 samples allocated to each treatment type: heat treatment by hardening, tempering, and thermochemical treatment by oxidation. To ensure comparability and scientific interpretability of the results, an identical applied force level was utilized for both treatment conditions. The frequency changes were monitored to evaluate the behavior of the materials under repeated stresses. Finally, the frequency changes were correlated with the number of cycles to identify when microcracks appeared and their evolution. The primary findings of this study indicate substantial disparities between the longevity of thermally and thermochemically modified specimens and the onset of microcrack formation in the material. Full article

Dairy wastewater is an agro-industrial effluent characterized by elevated concentrations of organic matter, nutrients and suspended solids, posing environmental risks when inadequately treated. This study assessed the feasibility of a simultaneous Scenedesmus obliquus–Lemna minor co-cultivation system within a single, shared bioreactor for the treatment of modified dairy wastewater, comparing its performance against the two individual monocultures. Raw dairy wastewater was subjected to sequential heat treatment, ultrasound and filtration, which significantly altered its physicochemical composition (p < 0.05) prior to cultivation. Experiments were conducted in parallel laboratory-scale open reactors over 14 days with periodic sampling. The mixed system achieved the highest removal efficiencies (95.3% COD, 91.3% TOC, 97.1% NO₃-N and 94.6% PO₄-P), with rapid pollutant reduction during the first 3–6 days followed by a slower stabilization phase. Despite these high removal efficiencies, the final COD concentration remained relatively high in absolute terms, indicating that the system is best suited as an on-site pretreatment step at the dairy facility, reducing the organic and nutrient load prior to discharge into the municipal sewerage network for further treatment at a municipal WWTP. The recovered microalgal biomass was nutrient-rich and exhibited preliminary biofertilizer potential, as reflected in the positive growth trends observed in two of the three tested Lactuca sativa L. cultivars, although these did not reach statistical significance relative to controls. Overall, the integrated system represents an effective, low-impact approach combining pollutant removal, biomass valorization and circular bioeconomy principles. Full article

Viticulture is increasingly being threatened by the effects of climate change, particularly rising temperatures and prolonged drought, which can adversely affect vineyard management, productivity, and grape quality. To enhance vineyard resilience under Mediterranean conditions, this study evaluated the effectiveness of using two mineral particle films—calcined kaolin and basalt powder—as short-term adaptation tools for Nocera (Vitis vinifera L.) grapevines grown in the Faro DOC area (Sicily). Treatments were applied at key phenological stages to assess their capacity to mitigate thermal stress and preserve physiological activity during the hottest summer periods. Both formulations significantly improved yield components compared with untreated vines, primarily by reducing berry dehydration and maintaining bunch and berry mass. Treated vines also showed enhanced photosynthetic efficiency, higher stomatal conductance, and improved water use efficiency, indicating effective protection of the photosynthetic apparatus against heat- and light-induced stress. Must composition benefited from the treatments, demonstrating higher total soluble solids. The polyphenolic profile revealed treatment-specific metabolic responses: kaolin promoted higher flavanol and antioxidant accumulation, whereas basalt powder favored phenolic acids and UV-protective flavonols. Overall, mineral particle films proved to be valuable tools for sustaining productivity and grape quality in hot, dry seasons, supporting vineyard resilience without altering technological maturity. Full article

Chronic cyclic heat stress impairs thermoregulation, growth, tissue integrity, microbial metabolism, and stress-related molecular responses in broiler chickens. N-acetyl-L-cysteine, a cysteine donor involved in glutathione synthesis, has been proposed as a nutritional strategy to support stress adaptation. Therefore, this study evaluated NAC in 324 Ross 308 broilers allocated to thermoneutral conditions (TN, 7 pens), HS (HS, 10 pens), or HS plus 2000 mg/kg NAC (HS + NAC, 10 pens). From day 20 to 35, HS birds were exposed to 34 °C for 7 h/day and 26 °C otherwise, while TN birds were kept at 22 °C. Heat stress increased rectal temperature and respiratory rate (p < 0.001), reduced average daily gain, and increased drinking and gasping behavior (p < 0.05). Heat stress also increased hepatic cord disorganization, cerebral vacuolisation–necrocytosis, hepatic and cerebral HSP70 expression, and caecal propionate, while reducing cerebral apelin expression (p < 0.05). Jejunal villus morphology and microbiota α-diversity were unchanged, although caecal profiles indicated treatment-related shifts and potentially higher Bilophila spp. in heat-stressed birds. NAC did not improve growth, thermoregulation, oxidative status, caecal fermentation, microbial structure, or HSP70 expression. It increased jejunal villus fusion and hepatocellular vacuolation scores and reduced cerebral ghrelin expression (p < 0.05). In conclusion, heat stress impaired growth and induced tissue, microbial, fermentative, and cerebral gene-expression changes, whereas 2000 mg/kg NAC did not provide measurable protection under the chronic cyclic HS in the present study. Full article

Laminar counterflow multi-branch flames provide a canonical configuration for investigating interactions between oxidizer-rich and fuel-rich streams in liquid-oxygen/methane combustion systems. This study numerically investigates their flame structure and stability under transcritical conditions, with stability characterized by the extinction strain rate. Ideal-fluid (IF), partial real-fluid (PRF), and real-fluid (RF) models are compared to distinguish the effects of real-fluid thermodynamics and high-pressure transport corrections. The multi-branch flame comprises two premixed branches coupled with a central diffusion branch. Heat release from the premixed branches creates high-temperature plateaus that preheat the stagnation-region mixture and sustain the diffusion branch. Although the three models predict similar flame topologies, the IF model gives an extinction strain rate of $3.306\times {10}^6{\mathrm{s}}^{-1}$, whereas both PRF and RF predict $3.256\times {10}^6{\mathrm{s}}^{-1}$. Thus, the ideal-fluid treatment slightly overpredicts the extinction limit under the present reference condition, while high-pressure transport corrections influence the ignition location, peak temperature, and thermal diffusivity. Increasing pressure from 10 MPa to 40 MPa raises the extinction strain rate from $9.336\times {10}^5{\mathrm{s}}^{-1}$ to $4.867\times {10}^6{\mathrm{s}}^{-1}$ by strengthening heat release and reducing thermal diffusion from the high-temperature region. Oxidizer preheating markedly enhances flame stability, whereas fuel preheating has a weak effect. These findings establish the connection between real-fluid thermodynamics, branch interaction, and extinction stability, providing a physical basis for model selection, operating-condition optimization, and stability-margin assessment in transcritical liquid-oxygen/methane combustion systems. Full article

Mitochondrial unfolded protein response (UPR^mt) is crucial in preserving mitochondrial health and, consequently, in prolonging healthspan. Natural bioactive polysaccharides have emerged as a central focus for delaying senescence, although their links to mitochondrial stress responses remain incompletely understood. In this study, a purified fraction of Lycii Fructus polysaccharide (FSP) significantly extended lifespan, improved healthspan-related phenotypes, and enhanced resistance to heat, oxidative, and ultraviolet stress in C. elegans. FSP also preserved mitochondrial abundance and morphology, increased adenosine triphosphate (ATP) levels and mitochondrial membrane potential, and reduced reactive oxygen species. Transcriptomic and qPCR analyses, together with hsp-60 and hsp-6 reporter assays, showed an enhanced UPR^mt-associated response after FSP treatment. FSP-mediated lifespan extension was not observed in the atfs-1 and ubl-5 mutant strains, supporting pathway involvement of ATFS-1/UBL-5-dependent UPR^mt signaling. FSP reduced senescence-associated β-galactosidase positivity and improved mitochondrial function in human dermal fibroblasts. Our findings provide a vision of regulating UPR^mt for anti-aging interventions with plant polysaccharides and highlight the anti-aging potential of FSP by improving mitochondrial health. Full article

In the aircraft industry, with the growing demand for advanced, sustainable structural materials, researchers are increasingly focusing on developing Al-Zn-Mg-Cu alloys, particularly the Al 7075 alloy with micro-alloying elements. However, load and environmental conditions pose problems for the aircraft industry by significantly reducing fleet service life. Thus, researchers are keen to use micro-alloying elements such as Ni, Ce, Ag, Sn, Ti, and Cd with the Al 7xxx base alloy to achieve enhanced mechanical properties, particularly hardness and tensile strength. Besides micro-alloying, the heat treatment (HT) process and cold working also have a favorable effect on the improvement of the mechanical properties. However, the addition of micro-alloying elements improves those properties more than HT and cold working processes. In this review study, several mechanical properties of the alloy have been comprehensively covered, which helps to establish a comparative analysis between the heat-treated base alloy and heat-treated micro-alloyed Al alloy. The base alloy, after micro-alloying, becomes enriched, with a high formability and workability, high conductivity, and good erosion protection that significantly make these alloys sustainable for the aircraft industry. The impact of dynamic changes accompanying the use of this lightweight alloy, after identifying the sensible necessities for the development of techniques, can effectively change the whole concept of the structural design. Hence, the key emphasis of the present review lies in a better understanding of the correlation between the structure and properties of micro-alloyed Al 7xxx alloy, which heralds a new era for aircraft industries. Full article

Resilience and adaptation to extreme climate events have become an urgent necessity. As cities grow denser, increasing numbers of people are exposed to water scarcity, flooding, and power grid disruptions. Immediate action is required to safeguard human lives and property. Residential buildings exert a significant environmental impact throughout their operational phase, contributing to air, land, and water pollution. A more sustainable and proactive approach to building management is essential to reduce the consumption, processing, and disposal of natural resources. This article explores the potential for biogas production from decentralised/on-site wastewater treatment systems through the co-digestion of blackwater (BW) and kitchen waste (KW) for existing residential buildings located in densely populated urban areas using hybrid grids. It addresses the importance of wastewater source separation, the use of BW and KW blends to achieve the best biogas production, and the environmental, economic and social aspects of these systems’ implementation. An extensive literature review and state-of-the-art analysis were conducted to assess the potential, main challenges, and research directions in this field. The results indicate that decentralised anaerobic systems can be technically feasible, reducing grid energy dependence, optimising water use, and valorising digestate as fertiliser—fully aligned with the EU’s Green Deal and the UN Sustainable Development Goals regarding sustainability and circularity. However, few studies address the feasibility of BW (vacuum toilet) and KW co-digestion for combined heat and power generation in hybrid grids. Further pilot- and full-scale research is therefore needed to increase system reliability and social acceptance. Full article

Climate warming increasingly threatens honey bee health, yet diet-associated molecular patterns under thermal stress remain poorly understood. In this study, newly emerged honey bees were fed eight dietary treatments, including natural diets (honey and bee bread) and artificial diets (sugar syrup and pollen substitute diets), for 5 days before exposure to acute heat stress (45 °C for 4 h). Transcriptional responses were quantified by quantitative real-time PCR (qRT-PCR) using genes associated with nutrient sensing, metabolism, immunity, and stress responses, and the resulting expression profiles were analyzed using principal component analysis, hierarchical clustering, and univariate statistical analyses. Distinct diet-associated transcriptional patterns were observed under both baseline and heat-stress conditions. Under baseline conditions, transcriptional variation was primarily associated with nutrient-sensing and metabolic pathways, whereas under heat-stress conditions, metabolic and stress-response pathways contributed more strongly to transcriptional variation. Sugar syrup-fed honey bees exhibited elevated expression of several immune-related genes following heat stress, suggesting greater physiological disturbance. In contrast, honey- and bee bread-based diets exhibited more coordinated regulation of nutrient-sensing and metabolic pathways and comparatively lower expression of selected immune-related genes. These findings demonstrate that dietary quality is associated with distinct molecular profiles under thermal stress and provide mechanistic insights into the relationship between nutrition and gene expression under heat-stress conditions, supporting the development of nutrition-based strategies for promoting honey bee health under climate warming. Full article

FOXO/DAF-16 is involved in stress resistance and metabolic regulation, but the molecular mechanisms of its interaction with hypoxia remain unclear. This study aimed to evaluate the anti-hypoxic effects of Poecilobdella manillensis bioactive peptide (PMP) and to investigate whether IIS/FOXO acts as a key node in mediating the regulation of oxidative stress and metabolic reprogramming. In the chemical hypoxia model of Caenorhabditis elegans (C. elegans) induced by sodium sulfite, PMP treatment improved the survival status and movement, feeding, and reproductive ability of hypoxic C. elegans, and significantly increased their survival rate. It also reduced reactive oxygen species (ROS) and lipofuscin levels in C. elegans, enhancing their tolerance to oxidative and heat stress. In the terminal normobaric hypoxia mice model, PMP intervention prolonged the survival time of hypoxic mice, alleviated the damage of heart, lung, and brain tissues, and increased superoxide dismutase (SOD) activity and glutathione (GSH) levels, and decreased malondialdehyde (MDA) concentrations and lactate dehydrogenase (LDH) activity in serum and tissues of mice. ¹H-NMR metabolomics analysis showed that PMP treatment reversed hypoxia-induced abnormalities in key metabolites such as glucose, lactic acid, glutamic acid, and taurine. Next, we utilized C. elegans mutants deficient in daf-2, age-1, akt-1, daf-16, and hsp-16.2, and further observed the nuclear translocation of DAF-16 in DAF-16::GFP C. elegans. The results showed PMP induced DAF-16 nuclear translocation and upregulated the expression of downstream SOD-3. Key metabolites representing antioxidant and energy metabolism were measured in the daf-16 mutant C. elegans. The results showed that PMP intervention failed to restore the levels of glucose, lactic acid, glutamic acid, and taurine in the mutant. Finally, 12 peptides containing antioxidant-related bioactive amino acid residues in PMP were screened by UPLC-Q-Exactive-MS and peptide biological activity prediction. Among them, molecular docking showed that KPPGP had a good binding with FOXO1. In conclusion, in C. elegans, PMP activated DAF-16/FOXO by inhibiting the Insulin/insulin-like growth factor-1 signaling (IIS) pathway and regulated redox homeostasis and metabolic reprogramming to resist hypoxia injury, and this protective effect was also observed in mouse models. IIS/FOXO can be used as a key node to regulate oxidative stress and energy metabolism under hypoxic conditions, and the identification of KPPGP provides insights into the screening and study of bioactive peptides in natural products. Full article

HfO₂ based thin-film ferroelectrics are metastable at room temperature and transited to the dielectric monoclinic phase upon heating. The thermal stability of such ferroelectrics increases when thin-film oxides are buried (BOX) in silicon–ferroelectric–silicon (SFS) structures formed by SmartCut^®, where thin ferroelectric layers are stabilized by oxygen vacancies and tensile stresses in the BOX, which is similar to silicon-on-insulator (SOI) structures. The main characteristics of the ferroelectrics in MFS and SFS structures are residual polarization P_r and coercive field E_c, which are determined by the fraction of the metastable ferroelectric phases that are also stabilized due to the inserted Al impurity in HfO₂:Al₂O₃ 10:1 (HAO) and (HfO₂:ZrO₂):Al₂O₃ (1:1)₅:1 (HZAO) nanolaminates. SFS structures and SFS CMOS ICs were tested after all thermal treatments at temperatures 900–1000 °C with t_BOX = 10–20 nm (or equivalent oxide thickness EOT = 1–2 nm) in an industrial process as gate insulators for CMOS and dual-gate DG SFS transistors. Their characteristics simulated in TCAD Sentaurus and analytic models in LTspice are investigated for an analog content addressable memory (ACAM). Full article

This study investigates the microstructural evolution and mechanical behavior of a Ni-based superalloy subjected to combined heat treatment and laser processing. Quantitative analysis of γ′ Ni₃(Al,Ti) and η (Ni₃Ti) phase distributions were performed using SEM-based statistical methods. The results show that γ′ precipitates exhibit a fine and uniform distribution with sizes in the range of ~0.05–0.30 µm and a high number density (n ≈ 2916), whereas the η (${\mathrm{N}\mathrm{i}}_3$Ti) phase appears as relatively coarse particles (~0.1–0.6 µm) with lower number density (n ≈ 505). Laser treatment promotes redistribution of γ′ precipitates and suppresses η phase formation, resulting in improved microstructural homogeneity. Mechanical characterization reveals that optimal aging (2 h) yields the highest hardness of ~525 HV at 300 °C, while tensile properties show yield strength in the range of ~1000–1150 MPa and ultimate tensile strength of ~1300–1500 MPa. The results demonstrate a strong correlation between γ′ refinement and enhanced mechanical performance. These findings provide a quantitative understanding of phase evolution and establish a microstructure-property relationship for optimizing Ni-based superalloys. Full article

The temperature-dependent carbide precipitation behavior and mechanical properties in 31CrMoNiNbV secondary hardening martensitic steel were investigated over a tempering temperature range of 200–650 °C. Sequential carbide precipitation behavior was characterized using scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy, which was further correlated with tensile properties, hardness and low-temperature toughness. At the high tempering temperature of 580 °C, the investigated material achieved a well-balanced combination of tensile strength of 1633 MPa and total elongation of 15.1%, wherein tempering-induced M₂C precipitation contributed to strength retention, while dislocation recovery and the formation of high-angle grain boundaries led to concurrent improvement in ductility and toughness. A predictive framework linking tempering temperature to carbides evolution and the resultant mechanical properties has been established for the investigated material, guiding the microstructural and heat treatment parameter design of ultra-high strength secondary hardening martensitic steels. Full article

In this study, isothermal annealing of AA8014 aluminum alloy burst vents was performed at 250–500 °C for 10 s to 2 h, and Johnson–Mehl–Avrami–Kolmogorov (JMAK) kinetic analysis was employed to determine the recrystallization parameters at 300 °C. An Avrami exponent of n = 1.87 and an apparent activation energy of Q = 156 kJ/mol were obtained, revealing a recrystallization mechanism driven by high stored energy and synergistically regulated by particle-stimulated nucleation at coarse second-phase particles and Zener pinning by fine Al(Fe,Mn)Si dispersoids. The burst pressure evolution was highly temperature-dependent: annealing at or below 300 °C led to sluggish recrystallization and a gradual pressure decline, whereas annealing at 350 °C and above resulted in recrystallization completion within 10 s and a sharp pressure drop to a stable plateau of approximately 0.92 MPa. The Al(Fe,Mn)Si dispersoids showed no significant differences in size distribution or grain-boundary pinning after 1 h at both 300 °C and 500 °C. This invariance across the tested range rendered the microstructure and burst performance insensitive to process variations. A quantitative predictive model correlating the recrystallized fraction with the burst pressure was established, with prediction errors less than 4.1%. The 300–350 °C interval is identified as the critical temperature window for regulating recrystallization kinetics and burst pressure, providing a rational basis for the heat-treatment design of burst vents. Full article