Search Results (19,086)

We report on the study of the immobilization process of non-radioactive rhenium (Re), a chemical analogue of technetium-99 (⁹⁹Tc), in compounds based on magnesium potassium phosphate (MKP), as well as the possibility of enhancing their properties with iron-bearing additives/fillers. Powdered Re₂O₇ was used as the initial Re-containing source. Because of the solubility and high leachability of Tc (VII), which is also volatile at high temperatures, its immobilization for long-term storage and disposal poses a serious challenge to researchers. Taking this into account, low-temperature stabilization technology based on MKP, a cementitious material, is currently considered promising. We prepared experimental specimens based on Re-incorporated MKP matrices and analyzed their microstructure in detail using analytical methods of X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Considering that iron-bearing substances can reduce Tc (VII) to the lower-valence form Tc (IV), which is more stable, attention was also paid to evaluate the effect of fillers (Fe₂O₃, Fe₃O₄, Fe, FeS and blast furnace slag (BFS)) on strength, oxidation state, and water resistance (expressed as leaching cumulative concentration). The addition of fillers ensures the formation of denser compounds based on MKP after 28 days of curing under ambient conditions and increases their mechanical strength. The oxidation state of Re and the reduction from Re (VII) to Re (IV) was estimated using X-ray-absorption near-edge structure (XANES) analysis. Considering the Re leaching concentrations from tests using the ANS-16.1 standard in water, enhanced leachability indices (LI) for Re from MKP matrices were determined with the addition of iron-bearing fillers. Overall, the average LI values were greater than the minimum limit, indicating their acceptance for disposal recommended by the U.S. Nuclear Regulatory Commission. Full article

We present the first European intercomparison of primary flow measurement standards with hydrogen-enriched natural gas (up to 20% hydrogen in molar fraction) and natural gas with pressure up to 60 bar and volume flow rates in the range (5 to 160) m³/h. We describe the principles of operation of the primary standards and present the transfer standards, a rotary meter and an ultrasonic meter, used for the intercomparison. In many instances, the overlap between the different laboratories is satisfactory, but the collected results are limited and do not allow us to make advanced conclusions. In addition, we investigate the effect of nitrogen impurities (2% in molar fraction) on the performance of low-pressure gas meters for pure hydrogen using newly developed measurement standards. We present the methods and results of this investigation. We show that nitrogen impurities affect the volume flow measurements of an ultrasonic meter but seem to have little effect on a thermal mass flow meter. This paper explores future opportunities and challenges in international intercomparisons involving hydrogen blends and highlights key issues and solutions with hydrogen gas metering in the presence of impurities. Full article

Landslides are complex geological phenomena that pose significant hazards to human life, infrastructure, and the environment. Understanding their mechanisms requires reliable data and advanced analytical methods. Thermal surveys offer valuable insights into surface temperature variations and moisture distribution, supporting the detection of precursory signs of slope instability. Numerical modeling, in turn, enables the simulation of physical processes that control landslide activation and propagation, as well as the prediction of potential landslide-affected zones. This study presents a bibliometric analysis of Scopus-indexed publications from January 2005 to March 2025, focusing on the integration of thermal surveys and numerical modeling in landslide research. The results highlight a steady increase in publications over the past two decades, reflecting growing interest in these innovative approaches. China and Italy are the leading contributors in terms of the number of publications, while Italy achieved the highest citation impact, with 445 total citations. These findings highlight the emerging research trends, showing the potential of combining thermal and thermo-numerical methods to enhance landslide monitoring and mitigation strategies. Full article

Staphylococcus are common bacteria that can be a component of the natural microbiota of the body of human and animal hosts or cause serious infections. The aim of this study was to analyze the presence of S. aureus in samples from two sheep breeds (Świniarka and Uhruska), assess the antimicrobial susceptibility and virulence profile of these microorganisms, and perform molecular comparative analysis of these bacteria. One hundred and three isolates of S. aureus strains were obtained (including five MRSA strains) and the highest phenotypic resistance to tetracycline (46.6%), clindamycin (45.6%), erythromycin (39.8%), and penicillin (31.1%) was confirmed. The tetL gene (27.2%) and the seB gene (44.7%) were the most frequently detected in strains. Three new sequence types in the MRSA isolates (ST 9313, ST 9314, ST 9315) were identified. In conclusion, our results confirm that sheep are significant reservoirs of S. aureus, especially MRSA strains, varying in terms of both resistance and virulence and with the potential to spread between individuals in the same herd, which may pose a potential health problem. Full article

Background: Silver(I) complexes with aromatic heterocyclic ligands are well known for their broad antimicrobial potential, largely attributed to their ability to interact with biomolecular targets. Results and Discussion: In this study, a new polynuclear silver(I) complex with N-(3′-phenylpropyl)quinoxaline-2-carboxamide (pqx-2ca), [Ag(NO₃)(pqx-2ca)]_n, was synthesized. Its structure was confirmed by single-crystal X-ray diffraction and comprehensively characterized using NMR, IR, and UV–Vis spectroscopy, while its behavior in solution was further elucidated through density functional theory (DFT) calculations combined with spectral simulations. The complex demonstrated significantly enhanced antimycobacterial activity compared with the free ligand when tested against the avirulent Mycobacterium tuberculosis H37Ra, fast-growing model organisms M. smegmatis and M. aurum, as well as the nontuberculous species M. avium and M. kansasii. Experimental and docking studies confirmed stable binding of the complex to subdomain III of bovine serum albumin (BSA) and to the minor groove of DNA. Furthermore, docking to validated mycobacterial targets revealed inhibitory potential toward the InhA and MmpL3 proteins, with binding affinities comparable to those of standard inhibitors. Conclusions: These results highlight [Ag(NO₃)(pqx-2ca)]_n as a promising candidate for the development of silver-based antimycobacterial agents with a dual mechanism of action involving both DNA and protein targets. Full article

Cryopreservation is a critical strategy for the long-term conservation of plant germplasm, particularly for clonally propagated crops, endangered species, and plants producing recalcitrant seeds. Hydrogel-based encapsulation systems can improve survival during ultra-low-temperature storage by providing mechanical protection, moderating dehydration, and regulating cryoprotectant uptake. Although calcium–alginate beads remain the traditional matrix for encapsulation–dehydration and encapsulation–vitrification, recent advances in biomaterials science have enabled the development of composite polysaccharide blends, protein-based matrices, synthetic polymer networks, macroporous cryogels, and functionalized hybrid hydrogels incorporating surfactants, antioxidants, or nanomaterials. These engineered systems provide improved control over water state, pore architecture, diffusion kinetics, and thermal behavior, thereby reducing cryoinjury and enhancing post-thaw recovery across diverse plant explants. This review synthesizes current knowledge on hydrogel platforms used in plant cryopreservation, with emphasis on how physicochemical properties influence dehydration dynamics, cryoprotectant transport, vitrification stability, and rewarming responses. Performance across major explant types is assessed, key limitations in existing materials and protocols are identified, and design principles for next-generation hydrogel systems are outlined. Future progress will depend on material standardization, integration with automated cryopreservation workflows, and the development of responsive hydrogel matrices capable of mitigating cryogenic stresses. Full article

A recent phylogenetic reconstruction based on molecular genetic data revealed the presence of six well-supported clades within the freshwater fish family Nemacheilidae (Burmese, Eastern, Indochinese, Northern, Southern and Sundaic Clade). Species with the present generic name Schistura were found in three of the six major clades. Since the type species of Schistura belongs to the Southern Clade, species in other major clades can no longer be considered as members of the genus Schistura. We here review the generic status of ‘Schistura’ species in the Burmese Clade. ‘Schistura’ savona represents an isolated lineage, for which the genus Acoura is available, previously a synonym of Schistura. A second group comprises two species, ‘Schistura’ kohchangensis and the undescribed ‘Schistura’ cf. kohchangensis. We propose Pogonoschistura as a new generic name for these two species and name the undescribed species. Pogonoschistura differs from all other genera within the Burmese Clade by the combination of the following character states: caudal fin slightly emarginate to emarginate; adult males with a suborbital flap and a suborbital groove; dorsal fin with 7½ or 8½ branched rays; lips not covered by papillae; anus closer to anal-fin base than to pelvic-fin base; and lateral line incomplete, but exceeding vertical through pelvic-fin origin. Pogonoschistura pawaiensis, new species, is distinguished from its congener by having 9+8 branched rays in caudal fin, 7½ branched rays in dorsal fin and a distinct head pigmentation pattern. Full article

The microstructure and properties of a cobalt-free, cost-effective Al_0.4CrFe₂Ni₂ medium-entropy alloy (MEA) after multi-stage thermomechanical processing, including annealing, rolling over a wide temperature range from hot to cryogenic conditions, and subsequent precipitation strengthening, were investigated in the present study. The initially cast microstructure was effectively homogenized through hot rolling with an 80% thickness reduction followed by homogenization annealing, resulting in the formation of a single-phase supersaturated solid solution and enhanced stability of plastic deformation. Strengthening of the MEA was achieved by rolling under both ambient and cryogenic conditions, with the deformation process predominantly governed by shear band formation. However, rolling under cryogenic conditions led to a more pronounced localization of plastic deformation, promoting the formation of deformation nanotwins and resulting in significantly higher strengthening compared to ambient rolling, with the alloy reaching a yield strength of 1040 MPa and an ultimate tensile strength of 1235 MPa. Precipitation hardening was governed by the formation of B2-type (ordered body-centered cubic, BCC) precipitates, which preferentially nucleated along deformation bands, thereby effectively strengthening the alloy to a yield strength of 1420 MPa and an ultimate tensile strength of 1465 MPa. Our results demonstrate that the investigated MEA offers a wide range of tunable mechanical properties, which can be effectively tailored through appropriate combinations of thermomechanical processing routes. Full article

Accurate Digital Terrain Models (DTMs) are essential for managing forest drainage networks as a crucial element of water management, yet dense canopies and complex micro-topography challenge Airborne Laser Scanning (ALS) precision. This study evaluates the vertical accuracy of an ALS-derived DTM specifically within forest drainage ditches, utilizing 706 GNSS and total station measurements for validation. The results indicate a positive elevation bias, with a mean elevation error of 0.415 m and an RMSE of 0.464 m, 54.7% higher than the 0.3 m declared in the DTM technical report. Forest height, acting as a proxy for forest structural density and canopy closure, was significantly associated with a reduction in ground reflection density and an increase in the distance to the nearest ground reflection (p < 0.05). Mixed-effects ANOVA confirmed that there are significantly more ground reflections in low vegetation (0–1 m). Crucially, multiple regression analysis revealed that forest height was not the primary driver of elevation error; instead, ditch geometry was the most significant predictor. Narrower ditches exhibited substantially higher errors than wider ones, regardless of the canopy height. Furthermore, while ground reflection density decreased in mature stands, this reduction did not significantly diminish DTM vertical accuracy, suggesting that some of the LiDAR reflections of low vegetation could be misclassified as ground reflections, decreasing accuracy. These findings suggest that while ALS is effective for general forest topography and mapping drainage infrastructure, its application may require corrections for ditch dimensions rather than vegetation height alone to mitigate systematic overestimation of ditch bed elevations. Full article

Protective cultures are an increasingly industrially relevant biopreservation tool for meat and meat products, responding to simultaneous demands for microbiological safety, extended shelf life, and reduced reliance on synthetic preservatives within clean-label frameworks. This review summarizes current advances in protective cultures applied to meat systems, with emphasis on technological functions, efficacy boundaries, and safety-related due diligence. We discuss the dominant inhibitory mechanisms of lactic acid bacteria and related protective taxa—acidification, competitive exclusion, and antimicrobial metabolites (including bacteriocins)—and highlight why performance is strongly strain- and matrix-dependent under realistic storage conditions. Practical applications are reviewed across raw meats (spoilage delay under refrigeration and vacuum/MAP) and processed or ready-to-eat products, where post-processing surface application emerges as a critical control point for limiting Listeria monocytogenes outgrowth during chilled storage. Key implementation constraints include technological compatibility and sensory neutrality, which are influenced by product buffering capacity, salt content, available fermentable substrates, packaging atmosphere, and temperature. From a safety perspective, we synthesize evidence on antimicrobial resistance in food-associated cultures and outline contemporary qualification strategies combining phenotypic susceptibility testing with genome-based screening to exclude acquired and potentially transferable resistance determinants. Overall, protective cultures should be viewed as a targeted hurdle integrated into holistic preservation systems rather than a standalone substitute for hygiene and process control. Full article

The ground impedance (insulation resistance R_isol) of photovoltaic (PV) modules is usually measured only in the dry state, even though arrays frequently operate under dew-wet or rain-wet conditions, when leakage paths can change. We measured dry insulation resistance R_dry and IEC 61215 MQT 15 wet leakage resistance R_wet for N = 37 field-aged crystalline-silicon modules from utility-scale plants and related the results to the IEC 40 MΩ·m² criterion (R_wet × A ≥ 40). The measurements used 1000 V DC and a 2 min dwell; R_wet was obtained in a salted bath with a solution resistivity < 3500 Ω·cm. The median R_dry was 42.4 GΩ, whereas the median R_wet was 462.5 MΩ, resulting in a median R_dry/R_wet ratio of ~110×. Three modules (8.1%) failed the 40 MΩ·m² limit already in the dry state, whereas eight modules (21.6%) failed under IEC-wet conditions; five were dry-pass/wet-fail cases that would have passed dry screening. For a representative area A = 1.8 m², a practical conservative dry triage threshold of approximately 55.5 GΩ identifies modules needing IEC-wet verification rather than serving as a stand-alone limit. Overall, combining dry and IEC-wet measurements improves safety and supports sustainability through resource-efficient repowering/revamping and end-of-life decisions in large PV fleets, particularly in hot climates. Full article

The present study evaluates the impact of cavitation on the performance of the chemical refining of rapeseed oils and the enzymatic interesterification of fat blends using a powerful UP400S ultrasonicator (400 W, 20 kHz). Ultrasound-assisted alkali neutralization achieved efficiency comparable to that of the conventional 60 min process in only 7 min, with similar refining losses (5.04–6.80 wt.%), although slightly higher lipid peroxidation was observed. Performing the ultrasound cavitation under a protective nitrogen atmosphere minimized the formation of lipid peroxides and their breakdown products (i.e., hexanal, nonanal), partially protected tocopherols, and improved oxidative stability (IP at 120 °C = 3.9–4.4 h). Ultrasound-assisted enzymatic interesterification (EIE) of palm kernel fat and a palm stearin blend catalyzed by immobilized lipases (Lipozyme TL IM, Lipozyme RM IM, Novozyme 435) was carried out for the first time. Cavitation accelerated triacylglycerol rearrangement, reduced reaction time from 6 h (9.0·10⁻³ to 1.6·10⁻² min⁻¹) to only 1 h (5.5·10⁻² to 1.2·10⁻¹ min⁻¹), and significantly affected melting point stabilization and solid fat content profile. In summary, ultrasound cavitation substantially enhanced mass transfer and reaction kinetics, demonstrating strong potential for process intensification in the edible oil industry. Further optimization of reaction conditions is required before large-scale industrial implementation. Full article

Based on previous knowledge on changes in the gut microbiota of weaned piglets, a mixture of five different Prevotella species, Anaerovibrio lipolyticus, and Mitsuokella multacida (a Prevotella mixture) was tested as potentially novel type of probiotics for weaned Large White piglets of mixed sexes. The mixture was provided orally on the day of weaning to piglets in the experimental group, and the microbiota composition at weaning and one week later was determined by 16S rRNA sequencing in rectal swabs of 14 control and 27 experimental piglets. Bacteroides and Escherichia significantly decreased, and Prevotella, Blautia, or Faecalibacterium increased in the microbiota of both control and experimental piglets one week after weaning. Bacteria from the Prevotella mixture were detected in the gut microbiota of experimental piglets; however, the same bacteria of environmental origin were also recorded in control piglets. Despite this, early and uniform administration of the Prevotella mixture affected the composition of the gut microbiota of experimental piglets one week after weaning. The families Lactobacillaceae and Lachnospiraceae were more abundant in the gut microbiota of experimental piglets, while Pasteurellaceae, Coriobacteriaceae, Bacteroidales RF16 group, and Methanobacteriaceae were more abundant in control piglets. The Prevotella-based bacterial mixture thus may represent a novel approach to modify gut microbiota and consequently gut health in weaned piglets. Full article

Acrylonitrile Styrene Acrylate (ASA) is widely used in outdoor structural applications due to its favorable mechanical stability and weather resistance; however, its temperature-dependent plastic behavior remains insufficiently characterized for accurate numerical simulation. This study presents a non-standard method of calibrating the temperature-dependent Johnson–Cook (J-C) plasticity model for ASA in the practical operating temperature range below the glass transition temperature. Uniaxial tensile tests at constant strain rate 0.01 s⁻¹ were performed at −10 °C, +23 °C, and +65 °C to characterize the effect of temperature on the material’s plastic response. The J-C parameters $A$, $B$, and $n$ were identified for each temperature separately and globally using least-squares optimization implemented in MATLAB R2024b, showing good agreement with the experimental stress–strain curves. The calibrated parameters were subsequently implemented in Abaqus 2024 and validated through finite element simulations of the tensile tests. Numerical predictions demonstrated a very high correlation with the experimental data across all temperatures, confirming that the J-C model accurately captures the hardening behavior of ASA. The presented parameter set and calibration methodology provide a reliable basis for future simulation-driven design, forming analysis, and structural assessment of ASA components subjected to variable thermal conditions. Full article