日向灘イワシ巾着網の模型実験-III 呈味アミノ酸中特にアラニン,グリシン含量に就て

Abstract

As the third step in the experimental studies of the purse seine in the stratified layer current*, a series of model experiments was made with the purpose of investigating the timely change of the tension of the purse line and the shape of the net in the coarse of pursing opera ?? ion. The model gear is the same as was used in the previous experiments 2). The pursing apparatus and the tension selfrecorder of the purse line were specially designed (Fig. 1). In the two cases; A, when the bottom margin of the net has sunk completely and B, when it is in course of sinking, the pursing was begun and then the tension was selfrecorded (Plate 1), at the same time, the transformation of the net was photograghed (Plate 2). As the results of this experiment, it was observed that in the case A, the tension of the purse line begins to act as soon as the pursing begins (Fig. 2), but in the case of B, it does not act untill the first 1/6 stage of pursing procedure is finished, and then it increases sharply (Fig. 3). After the first 1/2 stage, the changes of tension in both cases take the same pattern (Fig. 4). The case B was considered to be more dangerous than the case A for the occurrence of kankui**.