Effect of adding liquid glass on the compaction and reactive sintering of cermet Al2O3-Al

The salient features of the process of compaction and reactive sintering of Al₂O₃-Al cermet compacts with additions of liquid glass are studied. The introduction of 3–28 wt.% glass into the initial aluminum powder, consisting of plate-shaped particles with aluminum-oxide surface films, yields granular material with bulk mass 0.4–0.5 g/cm³. The salient features of the compaction of granular powder are studied by analyzing logarithmic diagrams. It is shown that reactive sintering of samples in air occurs in a filtration combustion regime, and the dry residue of liquid glass activates sintering, resulting in the formation of γ-Al₂O₃, θ-Al₂O₃, α-Na₂Si₂O₃, and Si nanodispersed inclusions in an aluminum matrix with a layered structure. The flexural strength of 2.40–2.45 g/cm³ cermet is 300–320 MPa. __________ Translated from Steklo i Keramika, No. 7, pp. 28–31, July, 2007.     

Engineering of functional supramacromolecular complexes of proteins (enzymes) using reversed micelles as matrix microreactors

The size of the inner water cavity of reversed micelles formedin a triple system ‘water-surfactant-organic solvent’can be widely varied by changing the degree of surfactant hydration.This gives grounds to use reversed micelles as matrix microreactorsfor the design of supramolecular complexes of proteins. Usingultracentrifugation analysis, it has been demonstrated thatthe oligomeric composition of various enzymes (ketoglutaratedehydrogenase, alkaline phosphatase, lactic dehydrogenase, glyceraldehyde-3-phosphatedehydrogenase) solubilized in reversed micelles of Aerosol OT[sodium bis(2-ethylehexyl)sulfosuccinate] in octane changesupon variation of the degree of hydration. An oligomeric complexforms under conditions when the radius of the micelle innercavity is big enough to incorporate this complex as a whole.At lower degrees of hydration the micelles ‘uncouple’such complexes to their components. The catalytic propertiesof various oligomeric complexes have been studied. Possibilitiesof using reversed micelles for the separation of subunits ofoligomeric enzymes under non-denaturating conditions have beendemonstrated. In particular, the isolated subunits of alkalinephosphatase, lactic dehydrogenase and glyceralde-hyde-3-phosphatedehydrogenase have been found to be active in Aerosol OT reversedmicelles. The dependences of the catalytic activity of oligomericenzymes represent saw-like curves. The maxima of the catalyticactivity observed at these curves relate to the functioningof various oligomeric forms of an enzyme. The radii of the micelleinner cavity under conditions when these maxima are observedcorrelate with the linear dimensions of the enzyme oligomericforms. Correlation of the position of a maximum with the shapeof an oligomeric complex is discussed.     

EDT Method for Multiple Labelled Objects Subject to Tied Distances

Machine Intelligence Research - The success of new scientific areas can be assessed by their potential for contributing to new theoretical approaches aligned with real-world applications. The...     

Low-temperature phase formation in the SrF2–LaF3 system

Phase formation in the SrF₂–LaF₃ system was studied at temperatures ranging from 300°C to 450°C using nitrate flux. The solubility of LaF₃ in SrF₂ decreases with decreasing temperature. The equilibrium width of the solid solution region Sr_1−xLa_xF_2+x at 400°C, it is 44.6 ± 0.4 mol% LaF₃ (x = 0.446), at 350°C — 38.3 ± 0.7 mol% LaF₃ (x = 0.383), and decreases almost to zero at 300°C.     

Internal Stresses, Corrosion and Electrochemical Behavior in Soils, and Stress Corrosion of Pipe Steels

The results of field tests carried out at main gas pipelines (MP) are shown. The distribution of internal stresses along the MP perimeter is obtained. Polarization currents at differently strained pipeline fragments are determined in soils taken at different distances from the failure epicenter. The mechanoelectrochemical effect is shown to be twice greater in failure soils. Its value can serve as a criterion of the stress corrosion probability.     

Surface saturation of low-carbon martensite steels with boron and copper

Conclusions  

Hydrogen redistribution in the solid solutions ZrV2Dx, 2.2≤x≤2.7.: II. Structure of the intermediate phase: ‘Lattice liquid crystal’. A neutron-diffraction study

We have studied the crystal structure of the uncommon phase with k=0 in ZrV₂D_x, 2.2<x<2.5, which is an intermediate between the hydrogen-disordered phase and two hydrogen superstructures, ZrV₂D_<2 with k=(1/2 1/2 1/2) and ZrV₂D_>2.7 with k=(001). This phase is a primary superstructure combining the features of the disordered phase and, depending on the hydrogen concentration, one or another superstructure with k≠0. Its lattice (translational symmetry) is the same as in the disordered phase, which is k=0. Simultaneously, the lattice sites (the hydrogen arrangement in them) are prototypes of the sites of the subsequent superstructure with k≠0. Specifically, each site of the primary superstructure with k=0 is a mix of the sites with different spatial orientation of the superstructure with k≠0. In this sense the primary superstructure can be considered as a ‘lattice liquid crystal’ whereas usual superstructure with k≠0 is a ‘lattice crystal’. In addition, we have determined the crystal structure of the ‘ordered’ phase with k=(001) in ZrV₂D_2.73. It is a transitional state between the primary superstructure and the regular superstructure with the same k.     

Scalable digital hardware for a trapped ion quantum computer

Quantum Information Processing - Many of the challenges of scaling quantum computer hardware lie at the interface between the qubits and the classical control signals used to manipulate them....