A model to assess the effectiveness of topical antipruritics

A model has been developed to determine the effectiveness of topical antipruritics. It utilizes controlled, experimentally induced itch and has demonstrated the effectiveness of the direct action on cutaneous receptor sites of a topical anesthetic, benzocaine, in a topical antipruritic formulation, and has been used to differentiate between two effective topical antipruritics. Three studies are presented: The first study examined the reliability of the experimentally induced itch. Several indices of reliability were computed from the data of this first study. Cronbach's alpha was 0.92. Winer's theta also was 0.92. Simple test-retest reliability, computed at intervals of 29 min, 1 day, and 6-7 days, resulted in Pearson correlations of 0.84, 0.73, and 0.60, respectively. In the second study, the model differentiated statistically between the itch relief resulting from the topical application of a formulation with 6% benzocaine and the same formulation without benzocaine. The third study examined 2 known topical antipruritics: one containing 6% benzocaine and the other 1% hydrocortisone. Both topical antipruritics were found to relieve itch; however, the benzocaine antipruritic produced statistically significantly greater itch relief in more subjects than the hydrocortisone antipruritic at both 1 and 30 min after application. These results demonstrate that OTC antipruritics can be differentiated for effectiveness.     

NMR Lineshape in Anisotropic Superconductors with Nonregular Vortex Lattice

The nuclear magnetic resonance line shapes within a primitive cell of the vortex lattice of the type II anisotropic superconductors in a case when a vortex is displaced on small distance a from a regular position in a primitive cell are constructed. The results of the numerical calculations show that displacement of the flux line lattice essentially changes the NMR lineshape. The derivative of the power of the absorption energy with respect to the magnetic field is calculated. It allows to obtain more detailed information about the real vortex lattice of a superconductor.     

Temperature Dependence of Brittle Fracture Toughness of Reactor Pressure-Vessel Steels upon Ductile Crack Growth

The main mechanisms of brittle fracture upon ductile crack growth are studied on the basis of the probabilistic model of brittle fracture and the deterministic model of ductile fracture, which were put forward by the authors earlier. The investigations are carried out on the reactor pressure-vessel steel 15Kh2NMFAA in the initial and embrittled states. The dependences of brittle-fracture probability on the stress intensity factor and the value of ductile crack growth are calculated for various temperatures. The temperature dependence of brittle fracture toughness in the initial and embrittled states is predicted with and without regard for ductile crack growth. The authors analyze the main factors that govern the above-mentioned relationships. The calculated results are compared to test data for CT-type compact specimens.     

The slag crust in high-temperature iron ore smelting

Conclusions The crust lining formed by the material being processed acts as a gasdynamic protector of the walls of the apparatus, and gives reliable service at a gas-flow temperature of about 3000°C with exposure to corrosive iron oxides. The structure of the slag —metal crust is stratified, i.e., the inner surface of the apparatus is represented by a crust of metal only, so that the products of smelting are protected from contamination by elements and their compounds from the refractory lining.Translated from Ogneupory. No. 7. pp. 42–45. July, 1976.