The vapour pressure of solvent above swollen polymer networks in relation to rubber elasticity theory

The difference between the vapour pressure of solvent above swollen crosslinked polyurethanes and that above linear polyurethane solutions has been determined experimentally. Comparison of the data over a range of volume fractions of solvent has enabled an estimate to be made of the factor B/A, the ratio of the “front factors” in the equation for the free energy of deformation of a crosslinked network. Previous experimental evidence, based on the modulus of crosslinked elastomers, has suggested that A is $\text{1}\text{2}$. The results of this work suggest that $\text{A = B}\text{=}\text{1}\text{2}$.     

Transport properties of photo-excited carriers in slightly compensated Hg0.785Cd0.215Te

Photo-Hall measurements are presented for slightly compensated n-type Hg_0.785Cd_0.215Te at 4 K where the electron mobility is limited by charged scattering centers. Using a 10.6 μm laser as the optical source, we observe that the electron mobility passes through a maximum as a function of photo-excited carrier density. Mobility expressions based on the Kane-band model are modified to incorporate neutralization of charged scattering centers by photo-excited carriers. Calculated mobility values are found to be in satisfactory agreement with the data. The observed decrease in mobility for high carrier densities is attributed to electron-hole scattering. The mobility enhancement at lower carrier densities is explained in terms of neutralization of charged acceptors.     

Endo addition of chlorosulfonyl isocyanate to norbornadienes

The addition of chlorosulfonyl isocyanate to several 7-substituted norbornadienes affords $\text{endo}$ and $\text{exo}$ addition products.     

Measurement of the statistics and spatial distribution of pulsed amplified spontaneous emission

The statistical and spatial distribution of a source of pulsed A.S.E. working in the linear regime are found to agree with those of spontaneous emission in a time short compared with a transition lifetime, as predicted by Allen et al.     

On the absorption of infrared radiation by electrons in semiconductor inversion layers

Resonances in the inversion layer for infrared fields normal to the interface do not occur at the electric subband splittings. They are shifted from the subband splittings by resonant screening of the infrared field. The corrections for (100) Si surfaces are shown to be comparable to the shifts ascribed to many-body effects.     

Iodometric microdetermination of phosphorus,sulfur and chlorine in organic compounds

Summary A method is presented for the determination of phosphorus, sulfur and chlorine in organic compounds in absence of nitrogen by iodometry. The titration is carried out in 50% acetone solution in order to eliminate the interference of hydrogen peroxide.

---

Zusammenfassung Ein Verfahren zur jodometrischen Bestimmung von Phosphor, Schwefel und Chlor in stickstofffreien organischen Verbindungen wurde vorgeschlagen. Die Titration erfolgt in 50% acetonischer Lösung, um die Störung durch Wasserstoffperoxid auszuschalten.