Effect of laser irradiation on failure mechanism of TiCp reinforcedtitanium composite coating produced by laser cladding

Laser cladding is an effective technique to coat a metallic substrate with a layer of a different nature.It has been widely reported that the most important combined parameters controlling the quality ofthe coating are the specific energy (E) and the powder density ( ). In the present work, clad depositsof Ti6Al4V + 60 wt.% TiC were prepared on a Ti6Al4V substrate using an optimum combination of Ec= 24 J/mm2 and c= 3 mg/mm2. These experiments were performed using a laser power of 400 and600 W, in order to study the effect of laser power on the properties of the clad. The microstructure, phasecomposition and nanohardness of the coatings were investigated by optical microscopy, scanning elec-tron microscopy and X-ray diffraction. During laser processing, TiC can be partially converted to TiCX(X = 0.5) due mainly to the TiC dissolution into the laser-generated melting pool and subsequent precipi-tation during cooling. It was observed that the lower laser power limit reduces primary TiC dissolution butit also promotes secondary carbide alignment at the interface. On the other hand, the damage mechanisminduced by high laser power is dominated by primary TiC particle cracking by the high stress concentra-tion at the particle matrix interface followed by ductile failure of the matrix. It is also remarkable thatirradiance affects the TiC/TiCxratio despite Ecand care fixed and it determines hardness distributioninside the coating.Authors thank MINECO funding in special the Training of Research Staff programme with the help BES-2009-013589 and the support of the Comision Interministerial de Ciencia y Tecnologia (CICYT), Spain, under Grant MAT2012-39124. This work was developed at the Materials Technology Unit of the Polytechnic University of Valencia associated to CSIC through the National Centre for Metallurgical Research (CENIM). Finally, thank the EU for the funding received through the FEDER help in the project UPOV08-3E-005 for the purchase of equipment and the Generalitat Valenciana for the help ACOMP/2012/094.Candel Bou, JJ.; Jiménez, J.; Franconetti Rodríguez, P.; Amigó Borrás, V. (2014). Effect of laser irradiation on failure mechanism of TiCp reinforcedtitanium composite coating produced by laser cladding. Journal of Materials Processing Technology. 214(11):2325-2332. https://doi.org/10.1016/j.jmatprotec.2014.04.035S232523322141

Synthesis, characterization, DNA binding ability, in vitro cytotoxicity, electrochemical properties and theoretical studies of copper(II) carboxylate complexes

Four copper(II) carboxylate complexes, namely [Cu2(μ-3,5-dinitrobenzoate-O,O')4(4-(dimethylamino)benzaldehyde)2] (1), [Cu2(μ-benzoate-O,O')4(benzoic acid)2] (2), [Cu2(μ-benzoate-O,O')4(H2O)2] [Cu(benzoate-O,O')2(imz)2].2H2O (3) and [Cu(benzoate-O,O')2(2-Me-imz)2] (4) (imz = imidazole, 2-Me-imz = 2-methyl-imidazole), were synthesized and comprehensively characterized by elemental analysis, spectroscopic methods, single crystal X-ray diffraction, cyclic voltammetry (CV), topological analysis as well as theoretical studies. Single crystal X-ray diffraction revealed that products 1 and 2 are dinuclear paddle-wheel complexes, compound 3 is a co-crystal containing mononuclear and dinuclear blocks, while compound 4 is a mononuclear complex. Hirshfeld surface analysis of the compounds rationalized different types of hydrogen bonds, which also lead to the generation of H-bonded networks in 3 and 4. Their topological analysis disclosed a uninodal 4-connected 2D layer with sql topology in 3 and a uninodal 2-connected 1D chain with 2C1 topology in 4. The interaction of 1–4 with calf thymus DNA was investigated by UV–visible and fluorescence spectroscopy, revealing a moderately strong non-intercalative mode of interaction. In vitro cytotoxicity study of the complexes on HepG2 (human liver hepatocellular carcinoma) cell lines revealed a significant inhibition activity. Electrochemical study of the complexes in CH3CN (1–3) and DMSO (4) solution showed a one electron transfer corresponding to Cu(III)Cu(II)/Cu(II)Cu(II) and Cu(II)Cu(II)/Cu(I)Cu(II) redox couples. The ΔE and Ipa/Ipc values suggest that the redox couples are quasireversible. The DFT study was performed to further rationalize the crystal structures and nuclearity of the obtained copper(II) complexes. © 2021 Elsevier B.V

Recent advances in the application of NMR methodologies to analyze the conformation, dynamics, and interactions of saccharides

25 p.-7 fig. Carbohydrate Chemistry: Chemical and Biological Approaches.Volume 44. Editors: Amélia Pilar Rauter, Thisbe K Lindhorst, Yves QueneauThis chapter is dedicated to the presentation of different examples of the application of solution NMR to the study of conformation, dynamics of sugar molecules (oligo and polysaccharides, glycopeptides and glycomimetics) including the investigation of glycanrelated molecular recognition events. It is not our intention to be exhaustive, rather to highlight diverse examples since 2016. They are presented depending on the chemical nature of the saccharide molecule, and on the different methodologies that can be employed.We thank MINECO (Spain, Projects) and the European Union (Project RECGLYCANMR and BACTIVAX) for financial support. AF also thanksMINECO for Juan de la Cierva contract.Peer reviewe