A study of the irradiation temperature coefficient for L-alanine and DL-alanine dosemeters.

Alanine dosimetry is now well established both as a reference and routine dosemeter for industrial irradiation processing. Accurate dosimetry under the relatively harsh conditions of industrial processing requires a characterisation of the parameters that influence the dosemeter response. The temperature of the dosemeter during irradiation is a difficult quantity to measure so that the accuracy of the temperature coefficient that governs the dosemeter response becomes a critical factor. Numerous publications have reported temperature coefficients for several types of alanine dosemeters. The observed differences in the measured values were commonly attributed to the differences in the polymer binder or the experimental design of the measurement. However, the data demonstrated a consistent difference in the temperature coefficients between l-alanine and dl-alanine. Since there were no commonalities in the dosemeter composition or the measurement methods applied, a clear conclusion is not possible. To resolve this issue, the two isomeric forms of alanine dosemeters were prepared and irradiated in an identical manner. The results indicated that the dl-alanine temperature coefficient is more than 50% higher than the l-alanine temperature coefficient.

STUDY OF THE AGE AND COMPARATIVE ANATOMY ABOUT THE ACTON OF LEVATOR AND TENSOR VELI PALATI MUSCLESON THE EUSTACHIAN TUBE / 解剖学报

The attachments of eustachian tube, levator and tensor veli palati muscles on the base of the skull were measured from the skulls of human adults, infants, newborns ad well as monkeys, dogs and rabbits, respectively. Anatomical characteristics of the levator and tensor veli palati muscles that related to eustachian tubal ventilation and skull morphology were analysed. In addition, some head specimens were dissected for contrast. Levator veli palati muscle (LVPM) lies in the posterioinferior of the eustachian tube. The angles between LVPM and median saggital plane and the angles between LVPM and horizontal plane of palate are larger and their ability of raising the eustachian tube is more effective in the adult than in the newborn and animal. From the eustachian tube to the hamulus, tensor veli palati muscle (TVPM) descends almost vertically in the adult, but ventroward in the newborn and animals, which suggested their different actions upon eustachian tube. The skull morphology of the human adult differs from child and animal, which changes the position and function of LVPM and TVPM. In conclusion, eustachian tube was opened by LVPM chiefly in the adult while by TVPM in the newborn and animal. The incidence of otitis media with effusion is higher in the infant as it is the trasitional stage that the action of TVPM had been decreased while that of LVPM would not have been established.