824 research outputs found
Inhibition Effect of N, N'-Dimethylaminoethanol on the Corrosion of Austenitic Stainless Steel Type 304
The effect of N,N'-dimethylaminoethanol on the corrosion of austenitic stainless steel type 304 in 3M
H2SO4 has been studied by weight-loss method and linear polarization measurement in different
concentrations of the compound. The inhibition efficiencies of the inhibitor compound on the corrosion of
the stainless steel were evaluated through assessment of the anodic and cathodic polarization curves of
the alloy, the spontaneity of the electrochemical process, inhibition mechanism and adsorption isotherm.
The inhibitor efficiency increased with increase in the inhibitor concentration. Results obtained reveal that
the inhibitor performed effectively on the stainless steel providing good protection against pitting and
uniform corrosion in the chloride containing acidic solutions. The compound act through physiochemical
mechanism on the stainless steel surface and obeyed Langmuir adsorption isotherm. The values of the
inhibition efficiency calculated from the two techniques are in reasonably good agreement. Polarization
studies showed that the compounds behave as mixed type inhibitor in the aggressive media
Structure and magnetic properties of nanogranular composites CoFeZr-alumina
The 5 to 15 μm thick nanocomposite films (Coo.45Fe0.45Zr0.10)x(Al2O3)1-x with 30 < x < 65
at.% sputtered in a chamber evacuated with pure Ar gas were studied using Mössbauer spectroscopy,
magnetization, complex magnetic permeability, and magneto-force microscopy (MFM) measurements.
In particular, the films with x < 40 at.% displayed superparamagnetic state at room
temperature (the lack of sextets in Mössbauer specta, non-hysteresis character of the magnetization
curves, invariability of real μ’ and imaginary μ’’ parts of magnetic permeabilities with x and high
resistivity. Near the percolation threshold ( x ≈ 40 - 45 at.%) Mössbauer specta displayed features
of the ferromagnetic sextet and the values of μ’ and μ’’ increased, approaching the maximum, as x
increasing due to the decrease of inter-particle distances. Moreover, effects of dipole-dipole and
exchange interactions of the nanoparticles resulted in the nucleation of the magneto-ordered granules
(magnetoclusters) including a few metallic nanoparticles. The MFM allowed to visualizing the
presence of magnetic labyrinth-like magnetic contrast that was formed by the metallic nanoparticles
near the percolation threshold. At x > 45 at.% the films behave like the “bulk” ferromagnetic sample
with occasional inclusions of dielectric phase.
1. INTRODUCTION
At present time high interest is given to granular
composite materials, which consist of metallic
nanosized particles randomly distributed within a
dielectric matrix, because they represent nearly
ideal systems for the study of nanostructured materials
with a big change of their composition. For
the first time, such materials (named as cermets)
were manufactured at the beginning of seventies
of the last century and during that decade the main
concepts concerning the electrical and magnetic
properties of composites were stated [1-5]. The interest
of these materials was renewed in the nineties,
of the previous century, because of their possible
applications in the magnetic field sensors and
as magnetic recording media. The study of magnetic
properties of iron, cobalt or nickel
nanoparticles embedded into a dielectric matrix has
shown [6] that reduction of volume fraction of the
metallic phase below the percolation threshold xC
resulted in metallic granules becoming a singledomain
and the nanocomposite as a whole displays
superparamagnetic properties at room te
Modelling of Training Program Development for Supply Chain Management Business Project Development: Practical Research Results
Abstract- the article discusses the issues related to information-analytical support of the management/strategy development for international supply chain management business projects within training program development (level 2 of IEBP management model system): the selection of the key meta-competences , forms and formats of project-based learning, the most preferred for the main task types characteristic of the attractive activities, selected during HR-organization strategy development for IEBP management (they provide a brief description of the problem statement for this level). The article describes in detail the development of MAI-hierarchies (general preliminary and refined in VS-modification) developed for this level. They provide calculations of multi-expert assessments during the implementation of the supply chain management business project "New supply chain management", and analyze the main problems associated with the made choice made. A brief overview of additional (corrective) models of the supply chain management process optimization/rationalization is provided for this level. It was founded that governments around the world need to play a prominent role in developing strategies to protect supply chains for the future and put in place more robust disaster recovery plans, including relevant stockpiles, to enable more resilient outcomes
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