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Results of single sweep triangular wave cyclic voltammetric studies on some substituted anilines in acetonitrile are reported. It has been found that, while the first reduction steps of nitroanilines are reversible that of chloroaniline is irreversible. The second reduction steps were found to be irreversible and the overall picture emerged of a multistep process involving reversible charge-transfer steps followed by an irreversible chemical reaction.

L-Histidinol, the last obligatory intermediate in histidine biosynthesis in microorganisms, was tested for its possible transformation to histidine in the young rat. When an equimolar amount of L-histidinol replaced L-histidine in the diet, the rats lost weight and had an impaired food efficiency. Intraperitoneal or subcutaneous injection of histidine promoted the growth of rats fed ad libitum a histidine-free diet. The similar parenteral administration of histidinol did not prevent weight loss in the animals. The results indicate that the rat cannot convert L-histidinol to L-histidine at a sufficiently fast rate to be detected by growth measurements.

The theory of two-dimensional instability of laminar flow of water over solid surfaces is extended to include the effects of heat transfer. The equation that governs the stability of these flows to Tollmien-Schlichting disturbances is the Orr-Sommerfeld equation “modified” to include the effect of viscosity variation with temperature. Numerical solutions to this equation at high Reynolds numbers are obtained using a new method of integration. The method makes use of the Gram-Schmidt orthogonalization technique to obtain linearly independent solutions upon numerically integrating the “modified Orr-Sommerfeld” equation using single precision arithmetic. The method leads to satisfactory answers for Reynolds numbers as high as Rδ* = 100,000. The analysis is applied to the case of flow over both heated and cooled flat plates. The results indicate that heating and cooling of the wall have a large influence on the stability of boundary-layer flow in water. At a free-stream temperature of 60 deg F and wall temperatures of 60, 90, 120, 135, 150, 200, and 300deg F, the critical Reynolds numbers Rδ* are 520, 7200, 15200, 15600, 14800, 10250, and 4600, respectively. At a free-stream temperature of 200F and wall temperature of 60 deg F (cooled case), the critical Reynolds number is 151. Therefore, it is evident that a heated wall has a stabilizing effect, whereas a cooled wall has a destabilizing effect. These stability calculations show that heating increases the critical Reynolds number to a maximum value (Rδ* max = 15,700 at a temperature of TW = 130 deg F) but that further heating decreases the critical Reynolds number. In order to determine the influence of the viscosity derivatives upon the results, the critical Reynolds number for the heated case of T∞ = 40 and TW = 130 deg F was determined using (a) the Orr-Sommerfeld equation and (b) the present governing equation. The resulting critical Reynolds numbers are Rδ* = 140,000 and 16,200, respectively. Therefore, it is concluded that the terms pertaining to the first and second derivatives of the viscosity have a considerable destabilizing influence.