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Production of nitroaryl secondary metabolites by wood-decaying fungi of<i> Phlebia</i> spp.
No full textFilamentous fungi produce secondary metabolites with multiple biochemical activities. For wood-decaying fungi of Basidiomycota, some of these compounds may act as redox-active mediators involved in biodegradation of lignocelluloses and biopolymers. Our aim was to identify natural aromatic compounds produced by white rot fungi of the genus Phlebia (Meruliaceae, Polyporales, Agaricomycetes), which comprises efficient decomposers of wood, wastes, and xenobiotics. Naturally produced aryl compounds were obtained by cultivating the fungi on a defined low-nitrogen liquid medium with glucose as carbon source. Culture supernatants were extracted and analyzed with UPLC-MS (ultra-performance liquid chromatography–mass spectrometry) and NMR (nuclear magnetic resonance). Enzyme assays, cultivation with 15N isotope–labeled nitrogen supplement, and aryl compound–feeding experiments were performed to assess biosynthesis mechanisms. Together with the well-known secondary metabolite veratryl alcohol and its enzymatic oxidation product veratraldehyde, we identified two nitroaryl derivatives, 6-nitroveratryl alcohol and 4-nitroveratrole, accumulating in culture supernatants of Phlebia spp. Cultivation of P. radiata isolate 2776 with NH4NO3 caused higher product yield of the nitroaryl compounds than 15NH4Cl supplementation, suggesting a role of nitrate ions in formation of nitroaryl products. With 15N-labeled supplementation, however, incorporation of nitrogen also from ammonium ions was observed. Although lignin peroxidase (LiP) enzyme activities correlated with appearance of nitroaryl compounds, their formation from veratryl alcohol by LiP was not accomplished in vitro in reaction mixtures with extracellular supernatants. In compound-feeding experiments, additional glycosylated derivative of 6-nitroveratryl alcohol was detected in P. radiata cultures, and nitroguaiacol was formed from nitroveratrole. These results indicate multiple pathways including both intra- and extracellular metabolism in biosynthesis and bioconversion of monoaromatic aryl compounds and their derivatives in fungi of Phlebia
Intercomparison exercise of easy-to-measure and non-volatile difficult-to-measure analysis in homogenised high activity steel
No full textIntercomparison exercises (IE) are a way for laboratories to test their analytical performance. In case of difficult-to-measure (DTM) radionuclide analysis, participation in IEs are important due to the lack of reference materials. This paper reports the results from an IE focusing on non-volatile DTM analysis in homogenised high activity steel. The IE was carried out according to the ISO 13528 standard, in which the performances are assessed using z score. The z scores were generally acceptable. The experimental results were compared with activation calculation results showing wide range of compatibility.</p
Cascade synthesis of diarylamines catalyzed by oxygen-rich and porous carbon
No full textActivated carbon derived porous materials, effectively enriched with OH and C[double bond, length as m-dash]O groups, were found to mediate, in a cascade manner, the condensation between anilines and 3-hexenones or β-tetralones, followed by their aromatization to diarylamines. The reaction proceeds via in situ formation of enamine intermediates which are subsequently oxidatively dehydrogenated in presence of a molecular oxidant under inert atmosphere. The functional groups on the carbon surface contributed actively to the catalysis: phenolic hydroxyl groups were found to promote the coupling of amines and ketones to imines and their tautomerization to enamines, while the C[double bond, length as m-dash]O groups of the quinoidic moieties catalyze the dehydrogenative aromatization step. The carbon material's extensive porous structure turns out to be critical to preserve the reactive β,γ-unsaturated cyclohexanone derivatives and their enamine intermediates from undesirable coupling and condensation side-reactions. The carbocatalyst can be regenerated by molecular N-oxo quinoline, which acts as a more convenient and cleaner stoichiometric oxidant in comparison with standard aerobic conditions (oxygen-rich atmosphere). The developed methodology delivered up to 93% yields for many diarylamines, formerly accessible exclusively via Pd-mediated couplings. Computational DFT study of possible enamine reaction modes with quinone model compounds, combined with kinetic isotope effects (KIE) suggest that the aromatization reaction is triggered by hydride abstraction at the benzylic position of the enamine intermediate
Electrification of district heating: The impact of electricity price volatility and distribution temperatures on the optimal capacity mix
Full text linkBecause of the increasing share of variable renewable energy in the power sector, the volatility of the electricity price has increased greatly. This, the electricity tax relief, and concerns about sustainability of combustible fuels have boosted the power-to-heat investments in the Finnish district heating systems. Especially, electric boilers, which have been nearly non-existent in the Finnish district heating systems, will see a rapid roll-out in the next few years. In this study, Backbone modelling framework was used to investigate the impact of increasing volatility of electricity price on optimal power-to-heat and thermal energy storage investments in the Finnish capital region. The impact of decreasing district heating temperatures was analysed as well. The sensitivity of the results to energy prices and thermal energy storage costs was tested.The results show that more volatile electricity price increased the profitability of the electric boilers and heat storages. Larger electric boiler capacity led to higher electricity consumption and peak power demand. The profitability of the heat pumps increased significantly with lower district heating temperatures, which also decreased the electricity consumption of the district heating system. The optimal capacity mix of the P2H technologies and heat storages was highly sensitive to the cost assumptions of the fuels and heat storages, but the total costs increased only a little, if the model was run with suboptimal capacity mix. Lower fuel prices decreased the heat pump investments, and higher prices increased. The impact of fuel prices on the electric boiler investments was not as clear
Low-Complexity ZNN Model Handling Time-Varying Generalized Matrix Inversion Problems with Multilayered Sensor-Related Disturbances Applied to Robot Manipulator
No full textSensor-related disturbances and measurement uncertainties often degrade the performance of dynamic neural network methods in solving time-varying problems, especially the time-varying generalized matrix inversion (TVGMI) problem, which serves as the computational foundation for real-time control and signal reconstruction tasks. Traditional zeroing neural network (ZNN) models for handling TVGMI problems usually require matrix inversion or vectorization operations, leading to high computational complexity and poor robustness under sensor disturbance or time-varying perturbations. To overcome these challenges, this article proposes a novel low-complexity ZNN (LCZNN) model that achieves efficient and unified computation of time-varying matrix inversion and pseudoinverse without involving inverse matrix computation. To further enhance robustness, the LCZNN model is extended to handle multilayered sensor-related disturbances, giving rise to three variants: the state-disturbed LCZNN (SDLCZNN), the velocity-disturbed LCZNN (VDLCZNN), and the hybrid-disturbed LCZNN (HDLCZNN) models. Each variant introduces structured compensation dynamics that enable accurate convergence under different disturbance scenarios. Rigorous theoretical analyses establish their convergence and stability properties. Comprehensive numerical experiments on representative TVGMI problems validate the low computational burden, fast convergence, and superior multilayered disturbance tolerance of the proposed LCZNN framework. Moreover, discrete algorithms derived via Euler discretization are applied to the real-time path-tracking inverse-kinematics control of robotic manipulators. Simulation and physical experimental results confirm that the proposed LCZNN-based algorithms achieve high tracking precision, strong robustness, and computational efficiency, making them well-suited for real-time robotic and control applications.</p
Cold Climate Wind: Challenges, Technological Solutions and Policy
No full textCold-climate wind power represents a major subset of onshore global capacity, with approximately one third of existing installations located in regions prone to low temperatures and icing. The main technical challenge in cold-climate conditions is ice accretion on turbine blades, which degrades aerodynamic performance and causes production losses, while ice falling from turbines poses a significant safety risk. These issues have driven the development of specialized technological solutions, including ice detection and mitigation systems and detailed forecasting models. In parallel, specific policy approaches have also been developed to address increased icing risks. This review focuses on wind turbine blade icing and related issues for onshore wind. It presents state-of-the-art technical solutions for icing-related challenges, as well as approaches for icing modeling and forecasting of icing conditions. In addition, relevant policies from different countries are reviewed. Production losses due to icing are highly variable, influenced by ice thickness, shape, and post-icing wind conditions. Accurate estimation and forecasting of these losses require advanced tools, ranging from SCADA-based analyses to machine learning methods and mesoscale weather prediction models. Ice detection technologies are being developed based on both direct and indirect measurement principles. Efforts to validate and certify these systems for operational use, such as automatically stopping and starting turbines, are ongoing. Icing mitigation includes both active technologies, such as blade heating systems, and passive approaches, such as icephobic coatings. Uncertainty quantification has become central to project financing and planning, with standards emerging to guide risk assessment. Policy and regulatory responses vary internationally: some regions, like Québec, mandate cold-climate certifications and real-time operational data reporting, while others focus on risk assessments and safety zones. Regulatory approaches remain somewhat fragmented and guided by local priorities. Further harmonization is needed to address critical safety issues such as ice throw
Mechanical characterisation of ITER-specification tungsten using tensile and small punch testing methods
No full textTungsten is widely recognised for its exceptional properties. The material exhibits a high melting point, excellent thermal conductivity, and strong resistance to radiation damage, making it a key material for fusion energy applications.In this work, two types of mechanical tests were conducted on ITER-specification tungsten (A.L.M.T, Japan): tensile and small punch testing (SPT). Tensile testing provides fundamental properties such as yield strength, and ultimate tensile strength in specific rolling directions. SPT on the other hand, which is biaxial in nature, offers comparable data using miniature specimens, thus enabling efficient characterisation with limited material. The study aims to characterise the mechanical properties of the material and explore a correlation factor between the two approaches.Re-evaluation of the SPT correlation factors of ITER-specification tungsten in this study revealed noticeable deviation from the commonly adopted value in the European standard, with the yield strength factor showing the largest discrepancy. Furthermore, all correlation factors exhibited a noticeable temperature and directional (anisotropy) dependence, highlighting the importance of using material-specific values for accurate properties estimation
