The quest for lowering energy consumption during thin film growth, as by magnetron sputtering, becomes of particular importance in view of sustainable development goals. A recently proposed solution ...combining high power impulse and direct current magnetron sputtering (HiPIMS/DCMS) relies on the use of heavy metal-ion irradiation, instead of conventionally employed resistive heating, to provide sufficient adatom mobility, in order to obtain high-quality dense films. The major fraction of process energy is used at the sputtering sources rather than for heating the entire vacuum vessel. The present study aims to investigate the W
densification effects as a function of increasing Al content in (Ti
Al
)
W
N films covering the entire range up to the practical solubility limits (y ~ 0.67). Layers with high Al content are attractive to industrial applications as the high temperature oxidation resistance increases with increasing Al concentration. The challenge is, however, to avoid precipitation of the hexagonal wurtzite AlN phase, which is softer. We report here that (Ti
Al
)
W
N layers with y = 0.66 and x = 0.05 grown by a combination of W-HiPIMS and TiAl-DCMS with the substrate bias V
synchronized to the W
-rich fluxes (to provide mobility in the absence of substrate heating) possess single-phase NaCl-structure, as confirmed by XRD and SAED patterns. The evidence provided by XTEM images and the residual oxygen content obtained from ERDA analyses reveals that the alloy films are dense without discernable porosity. The nanoindentation hardness is comparable to that of TiAlN films grown at 400-500 °C, while the residual stresses are very low. We established that the adatom mobility due to the heavy ion W
irradiation (in place of resistive heating) enables the growth of high-quality coatings at substrate temperatures not exceeding 130 °C provided that the W
momentum transfer per deposited metal atom is sufficiently high. The benefit of this novel film growth approach is not only the reduction of the process energy consumption by 83%, but also the possibility to coat temperature-sensitive substrates.
Automatic for the masses Petrov, Petre M
Automatic for the masses,
2015, 20150225, 2015, 2015-01-01, 2015-02-26
eBook
InAutomatic for the Masses, Petre M. Petrov offers a novel, theoretically informed account of the transition from modernism to Socialist Realism, tracing their connections through Modernist notions ...of agency and authorship.
A nanocomposite built of the hydrogen-bonded (HB) dimer liquid crystal 4-heptyloxybenzoic acid (7OBA) and Graphene oxide (GO) exhibiting a cascade of phase transitions and phases not typical for ...pristine 7OBA, was investigated by optical polarization microtexture analysis and Raman spectroscopy. We use the 7OBA/GO nanocomposite beacause of the effective functionalizing properties of GO to study the generation and development of the ferroelectric smectic CG phase in its bi-tilted configuration. For the appearance of the CG phase with its substructures we propose an explanation based on the HB formation between 7OBA dimers in closed and open conformations and the GO sheets, aided by the π–π interaction with graphene hexagons which are free from functional groups. We propose molecular and macroscopic models for the substructures CGcl and CGln and indicate their triclinic C1 symmetry, characterized by a polar vector directed oblique to the layers. This confirms that the bi-tilted CG and its substructures are ferroelectric in the bulk similarly to solid ferroelectrics, thus showing potential as material for controllable photonic functional devices.
The results of the study of the coagulation kinetics of graphite nanoparticle suspensions in aqueous AlCl3 and Th(NO3)4 electrolytes are presented. Electro-optical effects in disperse systems ...containing graphite particles allow to reliably investigate the coagulation kinetics in such systems. A method based on the analysis of changes of electro-optical effect relaxation dependencies in the process of coagulation was developed. The dependencies of the electrokinetic potential on the concentration of electrolytes are presented. Coagulation in such systems is observed if electrokinetic potential of graphite particles does not exceed 5 mV. At the isoelectric point, the fast coagulation theory is in good agreement with the observed processes of formation of aggregates from graphite particles. The conducted studies confirm the conclusion that the formation of aggregates from graphite particles with lyophobic surface is mainly influenced by the valence of the ions that determine the surface charge, and their other characteristics are of secondary importance.
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•Aqueous graphite colloid with particle size 20–400 nm was studied.•Coagulation kinetics of graphite nanoparticles at isoelectric point were studied using electro-optic technique.•The influence of multivalent salts AlCl3 and Th(NO3)4 is studied, compared and discussed.•At the isoelectric point, the formation rate of pair aggregates from particles corresponds to the theory of fast coagulation.
The plasmaphysical code is presented that makes it possible to simulate the energy distributions of atoms escaping from plasma of the toroidal facilities. The code includes calculations of the ...particle spatial distributions in the charge-exchange plasma target consisting of atoms and hydrogen-like impurity ions. The calculations of the charge-exchange target are performed in two ways: using the Monte Carlo method and solving the ionization balance equation in the coronal approximation. The code can be used to interpret the neutral particle analyzers (NPAs) data. In particular, with its help, the ion temperatures determined using the NPAs can be corrected. The code can be also used to estimate the atomic fluxes from plasma onto the first wall expected at the currently designed fusion facilities.
Academician A. D. Sakharov’s idea concerning the emission of atomic flux from hot plasma (1951) inspired scientists of A. F. Ioffe Physico-Technical Institute to create the first in the world ...instrument called Neutral Atom Analyzer in 1960 and then in 1961 to use it successfully on the Alpha device (USSR, 1958–1963). Now the analysis of fluxes of fast atoms referred to as Neutral Particle Analysis (NPA) is one of the main diagnostic methods for the ion component of plasma in tokamaks, stellarators, and other devices. NPA provides a unique opportunity for studying the ion distribution functions, ion temperatures and hydrogen isotope ratio in hot plasma. Neutral particle analyzers developed at the Ioffe Institute were widely used in the USSR until the late 1970s, and afterwards began to be employed worldwide. Since then, most of the information on the ion distribution functions and the behavior of fast ions in fusion plasma is obtained from NPA measurements on all leading magnetic confinement fusion systems worldwide. The specialized complex of atom analyzers currently being created at the Ioffe Institute is included in the primary list of ITER diagnostics. The integration of this complex on ITER is expected to begin in 2025.
During the period of field research to find ways to improve the elements of table carrot cultivation technology, we proposed a comprehensive resource-saving technology for the cultivation of carrot ...root crops on drip irrigation in the Lower Volga region. A hypothesis was put forward to increase the productivity and quality of table carrots through the use of new generation biological products and fertigation of crops using drip irrigation. The research program included a comparative assessment of the zoned table carrot variety Shantane (control) and promising Red Core and Santa Cruz hybrids, which belong to the same early maturity group. For this, mineral fertilizers were calculated in doses for the planned yields of 90, 110, and 130 t/ha, using drip irrigation. Biological preparations Agriful (concentration 3 and 4 l/ha) and Fertigrain Foliar (concentration 1.3 l/ha) were used, in addition, to their complex use together with mineral fertilizers.
Titanium-based vacuum coatings, such as TiN and TiO2, are being widely used for functionalization of the surfaces and for forming protective surface layers for a number of applications. In this ...study, TiN/TiO2 coatings were deposited by two physical vacuum deposition (PVD) methods: cathodic-arc (for TiN) and glow-discharge (for TiO2) deposition. We studied the bilayer film composition, structure and properties by means of X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and scratch test analysis. The XRD spectrum indicated the presence of both anatase and rutile TiO2 phases, together with TiN reflections. The Ti 2p, O 1s and N 1s core level of XPS spectra in the depth of the oxide up to the oxide-nitride interface indicated intimate heterojunction between the layers. This results in a lower coefficient of friction and improved adhesion strength of the TiN/TiO2 film compared with pristine TiN coating.
Vaccination of the population is one of the most effective countermeasures in responding to the pandemic caused by novel coronavirus infection. Therefore, scientists all over the world have been ...working to develop effective and safe vaccines. We have developed a synthetic peptide vaccine, EpiVacCorona, against novel SARS-CoV-2 coronavirus, which is a suspension for intramuscular administration containing a composition of chemically synthesized peptide immunogens of the S protein of SARS-CoV-2 coronavirus conjugated to a carrier protein and adsorbed on aluminum hydroxide. Phase I–II clinical trials of the vaccine have started that consist of two stages: Stage 1 is an open study of the safety, reactogenicity, and immunological activity of the vaccine with the involvement of 14 volunteers aged 18–30 years; Stage 2 is a single blind, comparative, randomized placebo-controlled study with the involvement of 86 volunteers. The study involved volunteers aged 18–60 years; the vaccine was injected intramuscularly twice, spaced 21 days apart between injections. All local reactions in response to vaccine administration were mild, such as a short-term pain at the injection site. There were no signs of development of local or systemic adverse reactions. The two-dose vaccination scheme induced the production of antibodies, specific to the antigens that make up the vaccine, in 100% of the volunteers. Seroconversion with a neutralizing antibody titer ≥ 1:20 was reported in 100% of the volunteers 21 days following the second immunization dose. No seroconversion was reported in the groups of volunteers vaccinated with a placebo. The peptide-based EpiVacCorona Vaccine has low reactogenicity and is a safe, immunogenic product. Clinical Trials Identifier: NCT04527575.
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