Role of vapor flow in the mechanism of levitation of a droplet-cluster dissipative structure

The rate of water evaporation has been experimentally determined under conditions that ensure the formation of a dissipative structure of the droplet cluster type [1, 2]. It is shown that, in the region of localization of a droplet cluster, the velocity of the vapor-air flow is sufficient to maintain the levitation of droplets over the liquid surface according to the Stokes mechanism.     

Application of a variational approach to the investigation of three-dimensional stress-strain states of layered plates on a rigid base

By using a variational approach, we deduce a system of resolving equations that describes the three-dimensional stress-strain state of a layered plate. For the special case of hinged support along the contour, this system is analytically solvable in the three-dimensional case. To verify the proposed approach, we compared our results with known solutions. The case of a plate supported by a rigid base is also investigated. Translated from Problemy Prochnosti, No. 6, pp. 86–94, November–December, 1997.     

Single crystal preparation and crystal structure of the Cu2Zn/Cd,Hg/SnSe4 compounds

Single crystals of Cu₂Zn/Cd/SnSe₄ were grown using a solution-fusion method. The crystal structure of the Cu₂Zn/Cd,Hg/SnSe₄ compounds were investigated using X-ray powder diffraction. These compounds crystallize in the stannite structure (space group I 2m) with the lattice parameters: a=0.56882(9), c=1.13378(9) nm, c/a=1.993 (Cu₂ZnSnSe₄), a=0.58337(2), c=1.14039(4) nm, c/a=1.955 (Cu₂CdSnSe₄) and a=0.58288(1), c=1.14179(2) nm, c/a=1.959 (Cu₂HgSnSe₄). Atomic parameters were refined in the isotropic approximation (R_I=0.0517, R_I=0.0511 and R_I=0.0695 for Cu₂ZnSnSe₄, Cu₂CdSnSe₄ and Cu₂HgSnSe₄, respectively).     

Protamine-Cre recombinase transgenes efficiently recombine target sequences in the male germ line of mice, but not in embryonic stem cells

The production of subtle or conditional mutations in mice through the combined use of site-specific and homologous recombination has become an increasingly widespread experimental paradigm in mammalian genetics. Embryonic stem cells containing recombinase transgenes that were expressed in the male germ line, but not in other tissues or in the embryonic stem cells themselves, would substantially simplify the production of such alleles. Here we show that transgenes comprised of the mouse protamine 1 promoter and the Cre recombinase coding sequence mediate the efficient recombination of a Cre target transgene in the male germ line, but not in other tissues. Embryonic stem cell lines generated from one of these transgenic strains were transfected with targeting vectors that included loxP-flanked selectable markers, and homologously recombined alleles containing the marker and functional loxP sites were isolated. These results establish the potential of the system for substantially reducing the time, effort, and resources required to produce homologously recombined alleles in mice that have been secondarily rearranged by a site-specific recombinase.     

Exact bounds on failure probability in the “strength-load” model with incomplete information

The infimum and supremum of failure probability (i. e., the probability that the load exceeds the strength) are obtained under the following assumptions: (a) one of the variables is Erlang distributed and the other has known mean and variance; (b) the distribution functions of both random variables are unknown and only the means and the upper bound of one of the distributions are known.Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 56–63, September–October, 1992.     

Press-moldcases made from centrifugally cast wear-resistant alloys

Conclusions The cases of press-molds having large linear dimensions and thin walls can be obtained from centrifugally cast high-chromium cast iron with subsequent hardening at 1080–1100°C in oil. The resistance of the experimental cases when first placed in the mold is three times greater than in ordinary cases made of 20Kh steel. The regrinding of the cases within the tolerance limits for refractory products, specified by GOST 5500-75, and subsequent operation without additional heat treatment, makes it possible to boost their overall resistance.Translated from Ogneupory, No. 1, pp. 21–23, January, 1981.