Effect of CO2 line width on 15 μm atmospheric emission

The effects of CO₂ spectral line width and density on the atmosphere's radiant intensity at ～710 cm^-1 are calculated. An increase of 30% in the currently accepted line width, justified on the basis of laboratory data, increases the prediction of radiant intensity by about 5%. The use of the increased line width leads to good agreement in a test case using satellite data. Nominal changes of a few per cent of the CO₂ density result in changes in the radiant intensity of a fraction of 1%.     

Resonances in neutral Bremsstrahlung

A strong resonance in the Bremsstrahlung emitted by electrons scattered by atomic nitrogen has been predicted by John and Williams.⁽¹⁾ This radiation resonance corresponds to the predicted elastic scattering resonance between electrons and atomic nitrogen. At 3360°K, the effective oscillator strength (f-number) for the free p to free s wave has a value of about 0.5, indicating that this resonance is a large fraction of the low temperature Bremsstrahlung in this system.     

A general formula for free-free absorption on highly-polarizable neutral atoms

A formula is given for the Maxwell-averaged, free-free absorption cross section for the case of highly- polarizable target atoms. The approximation is valid in the infrared and at temperatures of several thousand degrees Kelvin.     

Arithmetic three-spheres theorems for quasilinear Riccati type inequalities

We consider arithmetic three-spheres inequalities for solutions of certain second order quasilinear elliptic differential equations and inequalities with a Riccati-type drift term.     

Local Behavior of <Emphasis Type="Italic">p</Emphasis>-harmonic Green’s Functions in Metric Spaces

We describe the behavior of p-harmonic Green’s functions near a singularity in metric measure spaces equipped with a doubling measure and supporting a Poincaré inequality.     

Substituent effects on the ring-chain tautomerism of some 1,3-oxazolidine derivatives

The 14 and 70 eV electron ionization mass spectra of five sets (R1 = Me, Et, i-Pr, t-Bu and Ph) of seven 2-aryl-4-R1-substituted (Ar = C6H4X; X = p-NO2, m-Br, p-Cl, H, p-Me, p-OMe and p-NMe2) (1-5) and of seven 2-aryl-5-phenyl-substituted 1,3-oxazolidines (6; for Ar, see above) were recorded to study their ring-chain equilibria in the gas phase. These equilibria were also studied by 1H NMR spectroscopy in CDCl3 for compounds 5 and 6. A few 2,4- and 2,5-dimethyl-2-aryl derivatives (7, 8: Ar = C6H4X; X = m-Br, H and p-OMe) were studied both in CDCl3 and in the gas phase. The main characteristics of the ring-chain equilibria expressed by the variable SigmaRA% of the ring and of the chain form proved to be a strong dependence on the nature of the substituents on C-2 and C-4. The results in the gas phase are compared with those in CDCl3.     

SLE Boundary Visits

We study the probabilities with which chordal Schramm–Loewner evolutions (SLE) visit small neighborhoods of boundary points. We find formulas for general chordal SLE boundary visiting probability amplitudes, also known as SLE boundary zig-zags or order refined SLE multi-point Green’s functions on the boundary. Remarkably, an exact answer can be found to this important SLE question for an arbitrarily large number of marked points. The main technique employed is a spin chain–Coulomb gas correspondence between tensor product representations of a quantum group and functions given by Dotsenko–Fateev type integrals. We show how to express these integral formulas in terms of regularized real integrals, and we discuss their numerical evaluation. The results are universal in the sense that apart from an overall multiplicative constant the same formula gives the amplitude for many different formulations of the SLE boundary visit problem. The formula also applies to renormalized boundary visit probabilities for interfaces in critical lattice models of statistical mechanics: we compare the results with numerical simulations of percolation, loop-erased random walk, and Fortuin–Kasteleyn random cluster models at Q = 2 and Q = 3, and find good agreement.     

A generalized anisotropic and asymmetric yield criterion with adjustable complexity

During the past decades, numerous yield criteria for orthotropic materials, possibly showing tension–compression asymmetry, were developed. Although they were applied successfully to forming simulations, they are usually only adequate for a specific class of materials. The aim of this work is to present a generalized, pressure-independent criterion for plane stress states on the base of a two-dimensional Fourier series. Its complexity is adjustable through the number of considered Fourier coefficients, and thus, albeit using an associated flow rule, virtually any number of experimental data can be captured exactly. The criterion is applicable for materials with or without tension–compression asymmetry.