Surface Tension and Dynamic Contact Angle of Water in Thin Quartz Capillaries

The surface tension of water has been measured in quartz capillaries with radii from 200 down to 40 nm. It appears that the surface tension does not differ from the known (bulk) values in the temperature range from 8 to 70 degrees C, within 1% experimental error. The dynamic contact angle, theta(d), vanishes when the capillary surface is covered with a wetting film left behind the receding meniscus. In the case of a dry surface, theta(d) depends on the velocity of the meniscus motion. The results obtained do not agree with presently available theoretical predictions from hydrodynamic theories of dynamic contact angles. Rather the kinetics of water vapor adsorption ahead of the moving meniscus seems to be the major controlling agent of the dynamic contact angle. Copyright 2000 Academic Press.     

Pheromones of insects and their analogs LIV. Synthesis of dodec-9E-en-1-ol and its acetate —components of the sex pheromone ofSparganothis pilleriana

Using the Claisen rearrangement in the construction of a double bond with the E configuration, we have synthesized dodec-9E-en-l-ol and its acetate, which are components of the sex pheromone ofSparganothis pilleriana.Scientific Research Institute of Fine Organic Synthesis of the Academy of Sciences, Republic of Belarus. Ufa State Petroleum Technical University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 936–939, November–December, 1996. Original article submitted May 11, 1996.     

Features of microarc oxidation coatings formation technology in slurry electrolytes

A group of electrolytes composed of different powders entered into electrolyte presents a separate direction in microarc oxidation (MAO) technology. This group of electrolytes is most complex and however it has not been sufficiently studied yet. This paper shows that addition of powders of different nature into electrolyte influences both on properties of obtained coatings and on speed of their formation. The MAO-coatings formed in similar electrolytes-suspensions or slurry electrolytes (SE) contain in their composition an essential share of powder material entered into electrolyte as corpuscles of disperse phase (DP). Different nonmetallic combinations are used: oxides, carbides, borides, nitrides of metals and others. The particular conditions of microarc discharge regime (high temperature and pressure in a zone of breakdown) cause a thermolysis of electrolyte together with weighed corpuscles of solid matter, the realization of plasma chemical reactions on oxidizing surface and provide the synthesis of chemical combinations in an oxide matrix. A new composition of slurry electrolyte which allows improving the quality of obtained coatings on the basis of held investigations was developed.     

Hydrogen-like atom with nonnegative quantum distribution function

Among numerous approaches to probabilistic interpretation of conventional quantum mechanics (CQM), the closest to N. Bohr’s idea of the correspondence principle is the Blokhintzev-Terletsky approach of the quantum distribution function (QDF) on the coordinate-momentum (q, p) phase space. The detailed investigation of this approach has led to the correspondence rule of V.V. Kuryshkin parametrically dependent on a set of auxiliary functions. According to investigations of numerous authors, the existence and the explicit form of QDF depends on the correspondence rule between classical functions A(q, p) and quantum operator A. At the same time, the QDF corresponding to all known quantization rules turns out to be alternating in sign or overly complex valued. Finally nonexistence of nonnegative QDF in CQM was proved. On the other hand, from this follows the possibility to construct quantum mechanics where a nonnegative QDF exists. We consider a certain set of auxiliary functions to construct explicit expressions for operators O(H) for the hydrogen atom. Naturally, these operators differ from the related operator Ĥ in CQM, so that spherical coordinates are no longer separable for a hydrogen-like atom in quantum mechanics with nonnegative QDF. The text was submitted by the authors in English.     

A study of n-dodecylammonium acrylamido-2-methylpropanesulfonate association in aqueous solutions

Association of a micelle-forming monomer, n-dodecylammonium 2-acrylamido-2-methylpropanesulfonate, in aqueous solutions has been studied in a concentration range of 1.5 × 10^?3–2.5 × 10^?1 M with the use of conductometry, capillary and rotational viscometry, isothermal translational diffusion, and atomic force microscopy. Two critical micelle concentrations have been determined, and the shape of n-dodecylammonium 2-acrylamido-2-methylpropanesulfonate micelles has been proposed.     

Chitosan–Tripolyphosphate Nanoparticles: Synthesis by the Ionic Gelation Method,Properties, and Biological Activity

Russian Journal of General Chemistry - Nanoparticles with an average size of ~100 nm were obtained by ionic gelation of chitosan (M 6.5×103 and 60×103 Da) in the presence of...     

Smoothness of Stationary Subdivision on Irregular Meshes

We derive necessary and sufficient conditions for tangent plane and C ^k -continuity of stationary subdivision schemes near extraordinary vertices. Our criteria generalize most previously known conditions. We introduce a new approach to analysis of subdivision surfaces based on the idea of the universal surface . Any subdivision surface can be locally represented as a projection of the universal surface, which is uniquely defined by the subdivision scheme. This approach provides us with a more intuitive geometric understanding of subdivision near extraordinary vertices. February 16, 1998. Date revised: January 27, 1999. Date accepted: April 2, 1999.     

Explicit bounds for rational points near planar curves and metric Diophantine approximation

The primary goal of this paper is to complete the theory of metric Diophantine approximation initially developed in Beresnevich et al. (2007) [10] for C³ non-degenerate planar curves. With this goal in mind, here for the first time we obtain fully explicit bounds for the number of rational points near planar curves. Further, introducing a perturbational approach we bring the smoothness condition imposed on the curves down to C¹ (lowest possible). This way we broaden the notion of non-degeneracy in a natural direction and introduce a new topologically complete class of planar curves to the theory of Diophantine approximation. In summary, our findings improve and complete the main theorems of Beresnevich et al. (2007) [10] and extend the celebrated theorem of Kleinbock and Margulis (1998) [20] in dimension 2 beyond the notion of non-degeneracy.     

Commutativity of the centralizer of a subalgebra in a universal enveloping algebra

Let G be a reductive algebraic group over an algebraically closed field of characteristic zero, and let \(\mathfrak{h}\) be an algebraic subalgebra of the tangent Lie algebra \(\mathfrak{g}\) of G. We find all subalgebras \(\mathfrak{h}\) that have no nontrivial characters and whose centralizers \(\mathfrak{U}(\mathfrak{g})^\mathfrak{h} \) and \(P(\mathfrak{g})^\mathfrak{h} \) in the universal enveloping algebra \(\mathfrak{U}(\mathfrak{g})\) and in the associated graded algebra \(P(\mathfrak{g})\), respectively, are commutative. For all these subalgebras, we prove that \(\mathfrak{U}(\mathfrak{g})^\mathfrak{h} = \mathfrak{U}(\mathfrak{h})^\mathfrak{h} \otimes \mathfrak{U}(\mathfrak{g})^\mathfrak{g} \) and \(P(\mathfrak{g})^\mathfrak{h} = P(\mathfrak{h})^\mathfrak{h} \otimes P(\mathfrak{g})^\mathfrak{g} \). Furthermore, we obtain a criterion for the commutativity of \(\mathfrak{U}(\mathfrak{g})^\mathfrak{h} \) in terms of representation theory.