Vibration–Vibration energy exchange between N2O and CO

The temperature dependence of the vibration–vibration energy transfer between the v₃ mode of N₂O and the first vibrational level of CO was determined over a range of 780 to 1400°K using a shock tube. Several mixtures of CO-N₂O were tested, diluted in 95% Ar. The Landau–Teller plot of the vibration–vibration relaxation times has a least squares line of where pτvv is in atm ˙μsec and T in °K. The measured kinetic reaction was determined to be The transfer probabilities for this process were found to vary directly with temperature.     

A determination of the nitric oxide Einstein coefficient ratios

The ratios of the fundamental and first overtone A-values for NO vibrational levels 2–9 have been measured experimentally by observing the i.r. fluorescence from electron irradiated mixtures of N₂ and O₂.     

On multi-parameter bifurcation in diffusion models

The problem of bifurcation of periodic orbits from equilibrium when several parameters are present is discussed. The theory is developed from the viewpoint of differential equations on function spaces using the center manifold theory and the method of averaging. Theoretical and numerical analysis of a reaction-diffusion model is included.     

Thermographic investigation of high-power ultrasonic heating in materials

Results are reported on the use of an infrared thermovision imaging system to observe the surface temperature distribution caused by the application of high-power 20 kHz ultrasound to a variety of metal specimens and one fluoroplastic. Temperature increases of the order of 200°C were found to occur 20 to 30 s after initiation of insonation in resonant specimens of fine-grained polycrystalline brass, copper, and steel. Observation of extremely rapid temperature increases localized to the points of attachment of thermocouples to the test specimens casts strong doubt on all previous thermocouple temperature measurements made during similar experiments by earlier investigators. Fatigue cracks, artificially induced defects, and grain boundaries were also found to be sites of rapid localized heating during insonation.     

Reaction of halogens with some α,β-unsaturated aldehydes and ketones

Mechanisms are proposed to account for evidence indicating that some simple α,β-unsaturated aldehydes and ketones do not react with halogens by the expected attack on the CC bond.