Size distribution of convective thermals in the unstable stratified layer

An ensemble of convective thermals is considered in the layer of penetrative turbulent convection over a homogeneous heated horizontal surface. A model of an unsteady spontaneous jet is proposed to describe the dynamics of an isolated convective element. The model has an exact self-similar solution, which is used to derive a dynamic invariant that relates the velocity, temperature, and radius of the jet. The size distribution of spontaneous convective jets is derived, which agrees with the description of the fine structure of the atmospheric surface layer. The statistical size distribution of thermals is substantiated using the Fokker-Planck kinetic equation

Calculating the influence of substituents upon the dissociation constants of carboxylic acids

1. A general formula was proposed for calculating the dissociation constants of substituted acids, considering all the electrostatic interactions in dissociated and nondissociated forms of substituted and unsubstituted acids. 2. Interactions of the charge- induced dipole type play an important role in a number of cases, in particular, determining the ortho- effect to one degree or another. 3. The values of ΔpK were calculated for ortho-toluic and propionic acids in accord with the experimental data. © 1968 Consultants Bureau

Inductive interaction of weak dipoles in unsaturated and aromatic hydrocarbons and their derivatives

1. Calculation of induction according to the field effect mechanism is applicable to compounds containing differently hybridized carbon atoms. 2. The "zero" moments of the bonds Csp 3-Csp 2, Csp 3-Csp, and Csp 2-Csp were calculated according to the molecular orbital method as a linear combination of atomic orbitals (MO LCAO). 3. The dipole moments of a number of alkylbenzenes and their chloro-derivatives were calculated, in agreement with the experimental data. 4. An effect of saturation of induction is observed for fluoro-derivatives. © 1968 Consultants Bureau

Dipole moments and structure of adducts of methacrylonitrile with some cyclic dienes

1. Some adducts of methacrylonitrile with cyclic dienes were synthesized. 2. The dipole moments of six adducts were measured and some conclusions regarding their structure were drawn. © 1965 Consultants Bureau Enterprises Inc

Electronic and steric interactions in molecules of some aromatic dimethylamino derivatives

1. The additive scheme is applicable to calculating the Kerr constant and dipole moment of m-nitrodimethylaniline. 2. For 4-nitro-2-dimethylamlnotoluene the rotation of the (CH3)2N group relative to the {Mathematical expression} bond away from the CH3 substituent is coupled with an increase in the pyramidal nature of the nitrogen. © 1975 Plenum Publishing Corporation

Kerr constants and spatial structures of certain aryl vinyl compounds of sulfur

1. The aryl group is rotated by an angle of 65-75° with respect to the C-S-C plane in the aryl vinyl sulfones and their β-chloroderivatives containing H, CH3, CL, and Br substituents; in nitrophenyl vinyl sulfone, the rotation is 4-28°. 2. The unsaturated group inthe aryl vinyl sulfones, aryl trans-β-chlorovinyl sulfones, and the aryl trans-β-chlorovinyl sulfides have s-trans conformation, or something close thereto, displacement out of the C-S-C plane being as high as 40°. © 1977 Plenum Publishing CorporationPlenum Publishing Corporation

Anisotropy of the polarizability and steric structure of arylvinyl selenides and arylvinyl sulfides

1. Molecules of arylvinyl selenides have a maximally conjugated planar s-trans structure, 2. The conformations of arylvinyl sulfides are determined by the ratio of the energies of conjugation and steric repulsion of atoms; the disturbance of coplanarity occurs on account of rotation of the aryl radicals. © 1976 Plenum Publishing Corporation

Kerr constants and conformations of certain arylmethylsulfones

The conformations of the arylmethylsulfones in solution are such that the plane of the aromatic ring is shielded by one of the S→O bonds. © 1977 Plenum Publishing Corporation

Three-dimensional structure of phosphorus-containing heterocycles Communication 3. The gauche-orientation of the alkoxy group in 3-alkoxy-1-thia-3-phosphethanes

1. The dipole moments and Kerr constants of five 3-methoxy- and 3-phenoxy-l-thia-3-phosphethanes with a tetracoordinated phosphorus atom were determined. 2. On the basis of a graphical treatment of the data of these methods it was shown that the four-membered ring is bent, and the two-faced angle varies from 140 to 165°. The phosphoryl (or thiophosphoryl) group occupies a pseudoequatorial position; the methoxy and phenoxy radicals have a gaucheorientation. © 1974 Consultants Bureau

Steric structure of phosphorus-containing heterocycles - Communication 4. Axial arrangement of the alkoxy group in 1,3, 2-dioxaphosphorinanes according to the data of the method of dipole moments

1. The dipole moment of 2-alkoxy- and 2-phenoxy-l, 3,2-dioxaphosphorinanes and their spiro analogs with a tricoordinated phosphorus atom were determined. 2. A graphical method was proposed for the analysis of the data of the method of dipole moments of cyclic compounds. 3. In all the compounds studied, a chair conformation with axial (or diaxial for the spiro compound) arrangement of the alkoxy group with a gauche-orientation of the methoxyl and ethoxyl radicals and a cisorientation of the phenoxy group is realized. © 1974 Consultants Bureau