Search results for "Microscopy."
showing 10 items of 3331 documents
Investigation of Activities for Pt-M Bimetallic Nanoparticles Catalysts on the Oxygen Reduction Reaction
2015
Bi-metallic Pt3Ni/C and Pt3Co/C electrocatalysts were successfully synthesized by a solvent free chemical vapour deposition method with a narrow particle size distribution. The results showed that the electrochemical surface area was increased by adding the additional Ni or Co to a pure Pt catalyst. Pt3Ni/C catalyst exhibited a significant enhancement of oxygen reduction reaction activity. The catalysts were characterized by EDS, XRD, HRTEM and electrochemical activity was determined using cyclic voltammetry.
Easy Method for the Transformation of Levulinic Acid into Gamma-Valerolactone Using a Nickel Catalyst Derived from Nanocasted Nickel Oxide
2019
Different nickel catalysts have been tested for the transformation of levulinic acid into &gamma
Molybdenum blue: Binding to collagen fibres and microcrystal formation
2005
Collagen fibres have been shown by transmission electron microscopy to progressively bind the polyoxomolybdate ring-complex, termed molybdenum blue. Nucleation of cuboidal molybdenum blue microcrystals occurs on the surface of the collagen fibres, leading eventually to extensive coating of the fibres with microcrystals.
One pot light assisted green synthesis, storage and antimicrobial activity of dextran stabilized silver nanoparticles.
2014
Background Green synthesis of nanomaterials finds the edge over chemical methods due to its environmental compatibility. Herein, we report green synthesis of silver nanoparticles (Ag NPs) mediated with dextran. Dextran was used as a stabilizer and capping agent to synthesize Ag NPs using silver nitrate (AgNO3) under diffused sunlight conditions. Results UV–vis spectra of as synthesized Ag nanoparticles showed characteristic surface plasmon band in the range from ~405-452 nm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies showed spherical Ag NPs in the size regime of ~50-70 nm. Face centered cubic lattice of Ag NPs was confirmed by powder X-ray diffraction (PXRD…
Silver-loaded nanoparticles affect ex-vivo mechanical behavior and mineralization of dentin
2019
Background: The aim was to evaluate the effect of silver loaded nanoparticles (NPs) application on the triboscopic, crystallographic and viscoelastic properties of demineralized dentin. Polymethylmetacrylate-based NPs and Ag loaded NPs were applied on demineralized dentin. Material and Methods: Treated and untreated surfaces were probed by a nanoindenter to test viscoelasticity, and by atomic force microscopy to test nanoroughness and collagen fibril diameter. X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging were also used. Results: Dentin treated with Ag-NPs attained the lowest complex modulus, and the highest tan delta value…
Thermal Properties, Raman Spectroscopy and Tem Images of Neutron-Bombarded Graphite
2013
Neutron-irradiated graphite to a total dose of 3.6 × 1016 n cm−2 was studied by DSC, Raman spectroscopy and transmission electron microscopy (TEM). The Wigner energy of neutron-irradiated graphite was 9.5 J/g as measured by DSC; it was released with an exothermal peak at 220°C. The Raman spectroscopy has confirmed the expected effect caused by neutron irradiation of the graphite substrate. The TEM imaging has shown that neutron-irradiated graphite can be effectively exfoliated by sonication in comparison to pristine graphite, which under similar conditions does not exfoliate at all. The interstitial Frenkel defects in neutron-irradiated graphite are intercalated between the graphene layers …
On the correlation between mechanical and TEM studies of the aging of palladium during tritium storage
2005
Abstract Tritium has considerable technological applications in nuclear industry. Since it is a radioactive element, its storage is often considered in the form of tritides which ensure the required safety. However, the decay of tritium into 3 He alters the tritide properties during aging. With the aim of understanding the aging mechanisms of palladium tritide, a macroscale approach coupled with a microscopic study was performed on palladium aged up to eight months after tritium loading. The macroscale investigation based on the vibration of microcantilevers allowed the mechanical response of the material to be followed during its aging. The microscopic study was performed by Transmission E…
Highly Active Co3O4-Based Catalysts for Total Oxidation of Light C1–C3 Alkanes Prepared by a Simple Soft Chemistry Method: Effect of the Heat-T…
2021
9 figures, 2 tables.
IP 3 signalling regulates exogenous RNA i in C aenorhabditis elegans
2015
RNA interference (RNAi) is a widespread and widely exploited phenomenon. Here, we show that changing inositol 1,4,5-trisphosphate (IP3) signalling alters RNAi sensitivity in Caenorhabditis elegans. Reducing IP3 signalling enhances sensitivity to RNAi in a broad range of genes and tissues. Conversely up-regulating IP3 signalling decreases sensitivity. Tissue-specific rescue experiments suggest IP3 functions in the intestine. We also exploit IP3 signalling mutants to further enhance the sensitivity of RNAi hypersensitive strains. These results demonstrate that conserved cell signalling pathways can modify RNAi responses, implying that RNAi responses may be influenced by an animal's physiology…
From Single Molecules to Nanoscopically Structured Materials: Self-Assembly of Metal Chalcogenide/Metal Oxide Nanostructures Based on the Degree of P…
2011
A chemically specific and facile method for the immobilization of metal oxide nanoparticles onto the surface of IF-MoS2 nested fullerenes is reported. The modification strategy is based on the chalcophilic affinity of transition metals such as Fe2+/Fe3+, Fe3+, or Zn2+ as described by the Pearson HSAB concept. The binding capabilities of the 3d metals are dictated by their Pearson hardness. Pearson hard cations such as Fe3+ (Fe2O3) do not bind to the chalcogenide surfaces; borderline metals such as Fe2+ (Fe3O4) or Zn2+ (ZnO) bind reversibly. Pearson-soft metals like Au bind irreversibly. The immobilization of metal oxide nanoparticle colloids was monitored by transmission electron microscopy…