Analysis of the (ν1 + ν2) and (ν2 + ν3) combination bands of ozone

The fine structures of the (ν₁ + ν₂) and (ν₂ + ν₃) combination bands of ozone in the 5.7-μm region have been recorded and analyzed. The two vibrational states are coupled through Coriolis and second-order distortion terms. The interaction has been treated by the numerical diagonalization of the secular determinant for the two coupled states. With the centrifugal distortion parameters fixed to the ground state values, the following constants have been obtained: ν₁ + ν₂ = 1796.26₆, A₁₁₀ = 3.610₄, B₁₁₀ = 0.4414₅, $\text{C}{}^1{}_{110}\text{= 0.3902}{}_9$, ν₂ + ν₃ = 1726.52₆, A₀₁₁ = 3.553₇, B₀₁₁ = 0.4398₂, $\text{C}{}^1{}_{011}\text{= 0.3884}{}_4$, Y₁₃ = ?0.46₆, and X₁₃ = ?0.01₀ cm^?1. In addition, the following anharmonic constants have been obtained: x₁₂ = ?7.82₁ and x₂₃ = ?16.49₄ cm^?1. The value of the dipole moment ratio, $\text{R =}\text{〈011|μ}{}_{\mathrm{z}}\text{|0〉}\text{〈110|μ}{}_{\mathrm{x}}\text{|0〉}$, is 1.30 ± 0.10.     

Earphones in audiometry. Committee on Hearing, Bioacoustics, and Biomechanics. Commission on Behavioral and Social Sciences and Education. National Research Council Working Group

The advantages and disadvantages of three types of earphones for audiometric testing are discussed. Supraaural earphones continue to be recommended for this purpose, in preference to circumaural and insert types.     

The investigation of industrial plant processes using radiotracer techniques

Additional plant has been commissioned at the Springfields Works of BNFL to obtain increased production of uranium tetrafluoride. A programme of investigational work was undertaken during production to improve our understanding of the process. This paper describes some of the radiometric techniques used in the project, including passive gamma and neutron measurements and experiments using radioactive tracers.     

Determination of aflatoxins B1, B2, G1 and G2 by high-performance liquid chromatography with electrochemical detection

A new approach to the determination of afiatoxins B₁, B₂, G₁ and G₂ is given; the method involves high-performance liquid chromatography with amperometric detection in the differential-pulse mode at the dropping mercury electrode with 1-s drop time. These aflatoxins can be determined simultaneously with good resolution but with some compromise in sensitivity. The detection limit of underivatized aflatoxin standards is around 5 ng. Average recoveries of aflatoxins from peanut butter by the Beebe method were G₂ 81%, G₁ 87%, B₂ 77% and B₁ 76%.     

Turbulence measurements in a resonance tube

Experimental investigations of acoustically induced turbulence in a resonance tube have been performed. Frequency (f) and sound pressure level (I_p) effects have been studied. Measurements were made at various spatial locations on loops and nodes. Sampled data were processed to estimate the characteristics of turbulence. It is found that the acoustically induced turbulence appears when I_p exceeds 160 dB under the experimental conditions of f = 680–2740 Hz and I_p = 160–166 dB. The turbulent spectrum (F) and the wave number (κ) are found to satisfy a power law F ∝ K^s with $\text{s ? ?1·6}\text{to}\text{? 2·1}$. The r.m.s. turbulent velocity ($\text{u}\text{?}$) is experimentally found to have an $\text{I}{}_{\mathrm{p}}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ dependence, yet is relatively insensitive to the variation of f. Throughout the whole measuring range of f and I_p, the rate of energy dissipation per unit mass (ε) is estimated to be in the order of 10⁶–10⁷cm²/s³.     

Measurements of some reaction rates of importance in KrF lasers

A flowing afterglow method has been used to study a number of reactions of importance in KrF lasers using NF₃ as the fluorine donor. Total rate constants are reported for Kr^*(³ P ₂)+NF₃ and Kr⁺+NF₃. The thermal energy attachment coefficient has been measured for NF₃ and the cross section for the electron excitation process Kr^*(³ P ₂) +e→Kr^*(³ P ₁)+e has been estimated. The relevance of these results to discharge pumped KrF lasers is discussed.     

Ergodic properties of operator semigroups in general weak topologies

The aim of this paper is to study ergodic properties (i.e., properties about the limit of Cesàro averages) of a semigroup of bounded linear operators on a Banach space X, which is assumed to be continuous and locally integrable in the sense of a certain general weak topology of X. Then the results are applied to particular examples, such as locally strongly integrable semigroups, their dual semigroups, and the tensor product semigroup of two (C₀)-semigroups.     

Some complexes of rhodium and iridium with 2-(di-t-butylphosphinomethyl)-1-methoxy-4-methylbenzene

Summary The new tertiary phosphine t-13u₂(2-MeO-5-MeC₆H₃CH₂)P, L, was prepared by the base treatment of the phosphonium salt, LH⁺I^–, which was in turn prepared from t-Bu₂PH, 2-MeO-5-MeC₆H₃CH₂Cl and sodium iodide. This phosphine, L, reacts with various chloro-rhodium and -iridium species without O-demethylation. This contrasts with the behaviour of t-Bu₂PC₆H₄OMe-2 which demethylates readily on similar treatment to give chelate complexes. The completely different behaviour between this new 2-methoxybenzylphosphine, L, and the 2-anisylphosphine, t-Bu₂PC₆H₄OMe-2, is explained in terms of steric effects.No reprints are available.