The Effect of Inhibitors on the Susceptibility of Al 6013/SiC Interface to Localized Corrosion

Al 6013-20 SiC (p) in tempers T4, O, and F is sensitive to localized corrosion in 3.5 wt.% NaCl because of the preponderance of the secondary phase particles of Cu, Fe, and Cr at the Al/SiC interface. Treatment with cerium chloride effectively inhibited the localized corrosion of the alloy by suppressing the cathodic reactions at Al 6013/SiC interface as shown by electrochemical investigations. Morphological studies showed the formation of a protective cerium oxide/hydroxide films, which suppresses the corrosion of the alloy.     

Laser Cutting of Rectangular Blanks in Thick Sheet Steel: Effect of Cutting Speed on Thermal Stresses

Laser cutting of rectangular blank in thick sheet steel is considered and temperature as well as stress fields in the cutting section are predicted using the finite element method. The influence of cutting speed on temperature and stress levels is examined while the XRD technique is introduced to measure the residual stresses after the laser cutting process. The morphological and metallurgical changes in the cutting section are examined using the SEM and XRD. Microhardness across the cut cross section is measured. It is found that the temperature gradient along the y-axis changes, which modifies von Mises stress distribution along the y-axis. The residual stress predicted agrees with the measured data for all the cutting speeds employed in the present study.     

A new transrectal pull-through operation for high anorectal anomalies

Twenty-five cases of high anorectal anomalies were treated by a modified transrectal pull-through operation. All patients underwent diverting colostomy before definitive surgery, through which a balloon was passed into the blind rectal pouch. EMG studies were done at the site of the external sphincter in response to gradual inflation of the balloon. There was typical behavior both before and after surgery, except in two cases with sacral anomalies. These findings indicate the importance of a sensitive mucosa in the rectal pouch and of a functioning external sphincter. A modification of the pull-through technique in which a window of intact mucosa is left in situ to preserve sensation was employed in five cases and is expected to provide improved continence.     

Identification of isomers of nitrotoluene via free electron attachment

Free electron attachment to the three different isomers of mononitrotoluene molecules in the gas phase is studied using a crossed electron-molecule beams technique. In contrast to previous studies for a large number of negative ions, the presently measured relative cross section curves are recorded with an electron energy resolution of better than 100 meV. For several product anions including the nitro anion NO(2)-, remarkable differences for the three isomers are observed. In almost all fragment anion efficiency curves, the 2-nitrotoluene exhibits pronounced differences from the two other isomers. In contrast, 3- and 4-nitrotoluene disagree only slightly in a few fragment anions from each other.