Unexpected Reaction Pathway of the Alpha-Aminoalkyl Radical Derived from One-Electron Oxidation of S-Alkylglutathiones

Laser flash photolysis and high-resolution mass spectrometry were used to investigate the mechanism of one-electron oxidation of two S-alkylglutathiones using 3-carboxybenzophenone (3CB) as a photosensitizer. This report indicates an unexpected reaction pathway of the α-aminoalkyl radical cation (αN+) derived from the oxidation of S-alkylglutathiones. Instead of a common hydrolysis reaction of αN+ reported earlier for methionine and other sulfur-containing aminoacids and peptides, an intramolecular ring-closure reaction was found for S-alkylglutathiones

Can iPad Pro be as reliable as TLS for urban forest inventories?

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Microstructure and texture changes of MgLiAl alloys composed of alpha or alpha plus beta phases after twist channel angular pressing tcap

Two MgLiAl alloys of composition 4.5% Li and 1.5% Al (in wt.%) composed of alpha phase and of 9% Li, 1.5% Al composed of alpha(hcp) + beta(bcc) phases were subjected to twist channel angular pressing (TCAP) deformation. Such deformation of alpha + beta alloys caused less effective grain refinement than that of single alpha phase alloy. However, with increasing number of passes, grain size of single alpha phase alloy increased and that of beta phase in two phase alpha + beta alloy also grew, which suggested the effect of dynamic recrystallization. TEM studies allowed identifying particles of Li2MgAl phase of size of few mu m. {001} texture was observed in extruded alloy. Texture studies of extruded and TCAPed single phase hcp alloy indicated texture with {10 (1) over bar0} plane perpendicular to the extrusion direction and {0002} plane parallel to the extrusion direction. Duplex alpha + beta alloys showed poor texture development.Web of Science6341835182

Wetting of Sn-Zn-Ga and Sn-Zn-Na Alloys on Al and Ni Substrate

Wetting of Al and Ni substrate by Sn-Zn eutectic-based alloys with 0.5 (wt.%)of Ga and 0.2 (wt.%) of Na was studied using the sessile drop method in thepresence of ALU33 flux. Spreading tests were performed for 60 s, 180 s, and480 s of contact, at temperatures of 503 K, 523 K and 553 K (230C, 250C,and 280C). After cleaning the flux residue from solidified samples, thespreading areas of Sn-Zn0.5Ga and Sn-Zn0.2Na on Al and Ni substrate weredetermined. Selected, solidified solder-pad couples were cross-sectioned andsubjected to scanning electron microscopy with energy dispersive spectroscopy,x-ray diffraction study and synchrotron measurements of theinterfacial microstructure and identification of the phases. The growth of theintermetallic Ni5Zn21 phase layer was studied at the solder/Ni substrateinterface, and the kinetics of the formation and growth of the intermetalliclayer were determined. The formation of interlayers was not observed on theAl pads. On the contrary, dissolution of the Al substrate and migration of Alrichparticles into the bulk of the solder were observed

Promising Uses of the iPad Pro Point Clouds: The Case of the Trunk Flare Diameter Estimation in the Urban Forest

The rule of thumb “the right tree in the right place” is a common idea in different countries to avoid damages caused by trees on sidewalks. Although many new planting techniques can be used, the estimation of the trunk flare diameter (TFD) could help the planning process to give tree roots more space to grow over the years. As such, we compared the applicability of point clouds based on iPad Pro 2020 image processing and a precise terrestrial laser scanner (TLS FARO) for the modeling of the TFD using different modeling procedures. For both scanning methods, 100 open-grown and mature trees of 10 different species were scanned in an urban park in Cracow, Poland. To generate models, we used the PBH (perimeter at breast height) and TFD variables and simple linear regression procedures. We also tested machine learning algorithms. In general, the TFD value corresponded to two times the size of a given DBH (diameter at breast height) for both methods of point cloud acquisition. Linearized models showed similar statistics to machine learning techniques. The random forest algorithm showed the best fit for the TFD estimation, R2 = 0.8780 (iPad Pro), 0.8961 (TLS FARO), RMSE (m) = 0.0872 (iPad Pro), 0.0702 (TLS FARO). Point clouds generated from iPad Pro imageries (matching approach) promoted similar results as TLS FARO for the TFD estimations

Radiation- and Photo-Induced Oxidation Pathways of Methionine in Model Peptide Backbone under Anoxic Conditions

Within the reactive oxygen species (ROS) generated by cellular metabolisms, hydroxyl radicals (HO•) play an important role, being the most aggressive towards biomolecules. The reactions of HO• with methionine residues (Met) in peptides and proteins have been intensively studied, but some fundamental aspects remain unsolved. In the present study we examined the biomimetic model made of Ac-Met-OMe, as the simplest model peptide backbone, and of HO• generated by ionizing radiation in aqueous solutions under anoxic conditions. We performed the identification and quantification of transient species by pulse radiolysis and of final products by LC-MS and high-resolution MS/MS after γ-radiolysis. By parallel photochemical experiments, using 3-carboxybenzophenone (CB) triplet with the model peptide, we compared the outcomes in terms of short-lived intermediates and stable product identification. The result is a detailed mechanistic scheme of Met oxidation by HO•, and by CB triplets allowed for assigning transient species to the pathways of products formation

On the Disintegration of A1050/Ni201 Explosively Welded Clads Induced by Long-Term Annealing

The paper presents the microstructure and phase composition of the interface zone formed in the explosive welding process between technically pure aluminum and nickel. Low and high detonation velocities of 2000 and 2800 m/s were applied to expose the differences of the welded zone directly after the joining as well as subsequent long-term annealing. The large amount of the melted areas was observed composed of a variety of Al-Ni type intermetallics; however, the morphology varied from nearly flat to wavy with increasing detonation velocity. The applied heat treatment at 500 °C has resulted in the formation of Al3Ni and Al3Ni2 layers, which in the first stages of growth preserved the initial interface morphology. Due to the large differences in Al and Ni diffusivities, the porosity formation occurred for both types of clads. Faster consumption of Al3Ni phase at the expense of the growing Al3Ni2 phase, characterized by strong crystallographic texture, has been observed only for the weld obtained at low detonation velocity. As a result of the extended annealing time, the disintegration of the bond occurred due to crack propagation located at the A1050/Al3Ni2 interface