In the present study, chitosan coatings modified with g-C
3
N
4
were prepared for AZ91 magnesium alloy. The microstructure of the chitosan–g-C
3
N
4
coatings, depending on the concentration of the ...particles of the modifying phase in the chitosan solution, was investigated by scanning electron microscopy and X-ray phase analysis. It was found that coatings prepared in suspension of chitosan containing more than 30 g/dm
3
g-C
3
N
4
exhibited a complete wettability with a sodium-phosphate buffer solution. Confocal microscopy established the degree of inhibition of E. coli biofilm formation on the surface of the prepared coatings. It was found by using linear voltammetry and electrochemical impedance spectroscopy that the modification of chitosan by the g-C
3
N
4
particles led to an improvement in the protective properties of coatings.
The dependences of the protective properties of the anodic oxide coatings on the AD31 aluminum alloy surface modified with nitrates of magnesium, potassium, and some 3
d
-elements on the composition ...of sealing solutions and parameters of finishing treatment were established by scanning electron microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy, and salt spray chamber tests. A mechanism of the formation of modified anodic oxide coatings during sealing and subsequent thermal treating was proposed.
The mechanism of corrosion of AD31 (AA6063) aluminum alloy in 0.05 M NaCl solutions containing 0.03–5 mmol/dm
3
NaVO
3
as an inhibitor was studied. Using the data from potentiodynamic polarization ...measurements, the protective effect of the inhibitor is calculated, the Langmuir adsorption isotherm is constructed, and the effective activation energy of the anodic process is found. NMR spectroscopy is used to determine the ionic forms of vanadium compounds in aqueous solutions containing 3 mmol/dm
3
NaVO
3
. It is shown that the mechanism of the corrosion inhibition of AD31 alloy by soluble vanadates is the physical adsorption of inhibitor ions on the metal surface. This prevents the adsorption of oxygen, thus slowing its rate of cathodic reduction.
—
The stage mechanism of manganese-containing conversion coatings (MCCs) formation on the surface of AD31 alloy (AA6063) in acidic (pH 3) KMnO
4
solutions, as well as their structure, composition, ...and anticorrosion properties have been examined using scanning electron microscopy, energy dispersive X‑ray microanalysis, Raman spectroscopy, UV–Vis spectroscopy, electrochemical impedance spectroscopy, potentiodynamic polarization, and salt spray chamber tests. The conditions for obtaining MCCs have been optimized, and the feasibility of their use in multicomponent corrosion protection systems for the AD31 aluminum alloy has been shown.
World data on the lepton-charge asymmetry in the elastic and inelastic lepton scattering off the proton and nuclei are compiled and discussed. After reviewing the published results, we compare the ...elastic data to a model calculation of the two-photon-exchange mechanism. We show that the existing data do not provide any evidence for enhancement of the two-photon contribution. At confidence level 95% the data allow to exclude the two-photon exchange as an explanation for the difference between Rosenbluth and polarization transfer measurements of proton electromagnetic form factors.
The iron overload syndrome can be associated with various acquired states and hereditary factors. Hereditary hemochromatosis is the most common genetic disorder. Without therapeutic intervention the ...disease can lead to the development of life-threatening complications such as cirrhosis, hepatocellular carcinoma. The article presents data on pathogenesis, diagnosis and treatment of hereditary hemochromatosis. Own clinical observation is given.
The ice sheet is characterized by the development of fracture structures on a local and regional scale with the participation of fracture processes that occur at different scales, differing from each ...other by several orders of magnitude. The analysis shows that it is possible to distinguish a class of materials, which, in particular, include sea ice and other granular and structured materials (gypsum, concrete, paraffin, etc.), the effective fracture toughness of which during brittle fracture is affected by a large-scale factor, the role of which a gradient of external stresses appears. A model of this phenomenon is proposed for situations associated with variations in the local stress gradient with a change in the scale of the fracture region. Using the example of sea ice cover, we estimated the impact of the effect on the destruction scenarios of structured media.
The global need for energy in the world is constantly increasing. Critical fission reactors have proved great efficiency in the energy production, but the fear of nuclear wastes and accidents due to ...an uncontrolled chain reaction makes these unpleasant to public. More safe fusion reactors, on the opposite, have low efficiency. Hybrid reactors capable of using the advantages of both are studied, but not yet developed. In this paper, a simple fusion–fission pilot experiment model has been developed. A Tokamak with the same characteristics of DTT (Divertor Tokamak Test facility) has been considered as a reference machine for the fusion component. The fusion system has been coupled with a relatively simple low-power fission blanket configured into three different modes by using different fuels and materials. This model could be useful in order to investigate the properties of the fusion–fission hybrid coupling from a neutronic point of view.
PDF
