Leaching of lead cakes of zinc production in a complexing solvent

The process of leaching of lead cakes of zinc production in a complexing solvent—trilon B, which makes it possible to selectively extract lead into the solution—is studied with the use of mathematical modeling of the experiment. Its optimum conditions—pH, liquid-to-solid ratio within pulp, and temperature—are determined. The developed flow chart of cake processing provides zinc removal as a single product, recycling of zinc to the basic production, and reduction of current expenditure due to solvent regeneration.     

Improving the precipitation of arsenic trisulfide from washing waters of sulfuric-acid production of copper smelteries

Disadvantages of the sulfide method of purifying washing waters of the sulfuric-acid production are the formation of finely dispersed (particle size from 0.3 to 1.5 μm) difficult-to-filter precipitates of arsenic(III) sulfide and the danger of isolation of hydrogen sulfide into the atmosphere upon an overdose of sodium hydrosulfide. The coagulation of sols of arsenic sulfide is investigated in order to develop more efficient and rapid filtration technology of the precipitate. The filtration rate in various supply modes of sodium hydrosulfide and the dependence of settling rate and filtration on the presence of coagulants such as iron sulfate and aluminum sulfate are determined. It is established that the implementation of the distributed supply of sodium hydrosulfide during the precipitation of arsenic sulfide in combination with the application of such inorganic coagulant as iron(III) sulfate will make it possible to increase the particle size of the As₂S₃ phase by a factor of several times and increase the filtration and settling rates of pulps.     

Reversible addition of hydrogen to titanium alloys

This paper gives an overview of works on the reversible alloying of titanium alloys aiming at their much higher workability. The data cited convince the authors of the possibility of improving tangibly the whole technology of making products of titanium alloys for mechanical engineering applications.     

Crack Tip Opening Displacement in atomistic modeling of fracture of silicon

We analyze the fracture of single crystal silicon simulated by atomistic modeling with ReaxFF first principles based reactive force field. The simulations are performed at three temperatures: 500 K, 800 K and 1200 K, capturing both brittle and ductile behavior for the selected crystallographic orientation with (1 0 0) as the fracture plane. Three failure mechanisms are observed: bond breaking, amorphization and emission of dislocations. We demonstrate that the Crack Tip Opening Displacement (CTOD) gives a realistic estimate of the fracture toughness of brittle fracture, linking continuum mechanics fracture theory with the direct crack tip atomistic approach. We discuss the physics based mechanisms of failure in silicon in view of the CTOD measurements.     

The SARS-CoV-2 Delta-Omicron Recombinant Lineage (XD) Exhibits Immune-Escape Properties Similar to the Omicron (BA.1) Variant

Recently, a recombinant SARS-CoV-2 lineage, XD, emerged that harbors a spike gene that is largely derived from the Omicron variant BA.1 in the genetic background of the Delta variant. This finding raised concerns that the recombinant virus might exhibit altered biological properties as compared to the parental viruses and might pose an elevated threat to human health. Here, using pseudotyped particles, we show that ACE2 binding and cell tropism of XD mimics that of BA.1. Further, XD and BA.1 displayed comparable sensitivity to neutralization by antibodies induced upon vaccination with BNT162b2/Comirnaty (BNT) or BNT vaccination followed by breakthrough infection. Our findings reveal important biological commonalities between XD and Omicron BA.1 host cell entry and its inhibition by antibodies.     

Experimental study concerning the motion and the fragmentation of liquid droplets in a gas stream

This study concerns the motion of single water drops with a diameter from 100 to 300 in a gradient stream of air with a maximum velocity up to 200 m/sec. Empirical relations are derived for the basic critical numbers characterizing the motion and the acceleration of droplets in an air stream, as functions of time.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 23, No. 2, pp. 226–233, August, 1972.