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  • Risager Emborg posted an update 14 days ago

    Hafnium nitride (HfN) thin films with low electrical resistivity were obtained by inductively coupled plasma assisted magnetron sputtering as a function of ICP power. Microstructural, crystallographic and sheet resistance characterizations of HfN films were performed by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and 4 point probe method. The results show that ICP has significant effects on coating’s microstructure, structural and electrical properties of HfN films. With an increase in ICP power, thin film microstructure evolved from a porous columnar structure to a highly dense one. HfN thin films with different crystal structure and phases were obtained as a function of ICP power. The minimum resistivity of 125 µΩ-cm, the smoothest surface morphology with Ra roughness of 5.9 nm were obtained for the HfN films deposited at ICP power of 200 W.Nanocrystalline HfN thin films were deposited onto silicon substrates with direct current magnetron sputtering (dcMS) and mid-frequency magnetron sputtering (mfMS) by using hafnium metallic target with 3-inch diameter and 99.9% purity in argon/nitrogen atmosphere, under 4 different pulse frequencies and duty cycles. In order to evaluate the structural, morphological and mechanical properties, we used X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), nanoindentation tests. X-ray diffraction patterns show that films sputtered in dcMS mode have a mixed δ-HfN and HfN0.4 phases, whereas mfMS favor a single δ-HfN phase. mfMS leads to films with the higher mechanical hardness and smaller surface roughness than those of films deposited by dcMS. Hafnium nitride films with a single δ-HfN phase show the highest hardness values of 24.5 GPa while those of mixed δ-HfN and HfN0.4 phases show the lowest 18.3 GPa. In summary, the sputtering technique has a crucial role on the properties of the film and can be suitable used to adjust the structure and hardness of HfN films.This study evaluated the feasibility of low-cost nanoporous catalysts, such as dolomite and red mud, on the production of aromatic hydrocarbons via the catalytic pyrolysis of polyethylene terephthalate (PET). Compared to the non-catalytic pyrolysis of PET, catalytic pyrolysis over both dolomite and red mud produced larger amounts of aromatic hydrocarbons owing to their catalytic cracking efficiency and decarboxylation efficiency. Between the two catalysts, red mud, having a larger BET surface area and higher basicity than dolomite, showed higher efficiency for the production of aromatic hydrocarbons.The objective of this study is to evaluate the catalytic performance of pellet-type Ru/γ-Al₂O₃ as a catalyst during liquid-phase hydrogenation of the aromatic hydrocarbon. The Ru/γ-Al₂O₃ catalyst was prepared using a wet impregnation method. After adding a binder to Ru/γ-Al₂O₃, a pellet-type catalyst was obtained through an extrusion method. Nanoporous structures are well developed in the pellet-type Ru/γ-Al₂O₃ catalyst. MELK-8a purchase The average pore sizes of the Ru/γ-Al₂O₃ catalysts were approximately 10 nm. The catalytic performance of the pellet-type Ru/γ-Al₂O₃ catalyst during ethylbenzene hydrogenation was evaluated in a trickle-bed reactor. When the ruthenium loading increased from 1 to 5 wt%, the number of active sites effective for the hydrogenation of ethylbenzene increased proportionally. In order to maximize the conversion of ethylbenzene to ethylcyclohexane, it was necessary to maintain a liquid phase hydrogenation reaction in the trickle bed reactor. In this regards, the reaction temperature should be lower than 90 °C. The conversion of ethylbenzene to ethylcyclohexane on the Ru(5 wt%)/γ-Al₂O₃ catalyst was highest, which is ascribed to the largest number of active sites of the catalyst.Two reactive energetic plasticizers, 3-((2,2-dinitropropoxy)methoxy)prop-1-yne and 4-((2,2-dinitropropoxy)methoxy)but-1-yne which can react with an azido-containing poly(glycidyl azide-co-tetramethylene glycol) prepolymer by cupper-free 1,3-dipolor cycloaddition (“Click”) reaction, were synthesized and characterized, in order to investigate their plasticizing performance and catalyst-free 1,3-dipolar cycloaddition reactivity on energetic polyurethane binders. Two reactive energetic plasticizers showed better plasticizing performance than commercial energetic plasticizers. In the reactivity point of view, 3-((2,2-dinitropropoxy)methoxy)prop-1-yne exhibited higher Click reactivity than 4-((2,2-dinitropropoxy)methoxy)but-1-yne. Two synthesized plasticizers were found to fulfill the requirements for use as reactive energetic plasticizers.This study was conducted with a batch reaction to equilibrium isotherm, kinetic and thermodynamic parameters on adsorption of bromocresol purple (BCP), acid red 66 (AR 66) and acid blue 40 (AB 40) from aqueous solution by using activated carbon with nanopores. Freundlich and Temkin isotherm models were used to evaluate the suitability of isotherm for adsorption equilibrium data. The adsorption equilibrium was best fitted by Temkin model. The Freundlich separation factor values indicated that adsorption on the nanoporous activated carbon could effectively treat three dyes. The kinetic analysis of the adsorption process confirmed that it was more consistent with the pseudo second order model. The intraparticle diffusion was rate limiting step. The adsorption process of three dyes were endothermic because they were positive enthalpy values. The free energy values of three dyes decreased with increasing temperature, so that the spontaneity becomes higher with temperature increase. The activation energy value of three dyes were confirmed the physical adsorption.Inflammation mediated by the innate immune system is the organism’s protective mechanism against infectious environmental risk factors. Uncontrolled acute inflammation can become chronic, contributing to various chronic inflammatory diseases such as arthritis, asthma, autoimmune diseases, and atherosclerosis. Although microalgae are increasingly receiving attention as a source of bioactive molecules with therapeutic potential for various human diseases, the underlying mechanisms are not yet well understood. In the present study, we investigated the molecular mechanisms underlying the anti-inflammatory and anti-aging activities of ethanol extracts of Antarctic freshwater microalga Micractinium simplicissimum. Using RAW 264.7 macrophages, microalgal extracts exerted anti-inflammatory activity by regulating the major inflammatory indicators including cyclooxy-genase (COX)-2, interleukin (IL)-6, inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α and nitric oxide (NO). Besides, we observed the anti-aging activity of the microalgal extract by suppressing MMP-1 production in human dermal fibroblast.

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