ABSTRACT
BACKGROUND: The interaction between canopy and droplets is very important in the process of crop spraying. During the actual air-assisted application process, air-mist flow inevitably disturbs the leaves before droplets reaching them, which will also affect the final deposition state of the droplets on the leaf. Currently, researches on the interaction between droplets and the target leaf surface mainly focuses on the deposition behaviour on the surface of stationary target leaves rather than the dynamic leaves. Therefore, the deposition characteristics after the collision between the droplets and dynamic leaves are important for practical application and worth further study. RESULTS: Computational fluid dynamics simulations were performed to characterise the surface roughness, contact angle, and mechanical vibration. The interaction platform between the droplet and the vibrating pear leaf was built for experimental verification under laboratory conditions. The simulation results are in good agreement with the experimental results, which revealed the main reason for the droplet spreading and sliding was the inertial force generated by the relative velocity. It also indicated that the pear leaf vibration can improve the deposition of low-velocity and small droplets, which is different from that of static pear leaves. CONCLUSION: The deposition effect of droplets in vibrating pear leaves was investigated. This study also provides a simulation method for the collision between a vibrating leaf and moving droplets, and provides reference for the study of droplet deposition characteristics under the vibration of fruit trees.
ABSTRACT
OBJECTIVE: To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) on postoperative olfactory memory disorder in patients with general anesthesia of sevoflurane and to explore its possible mechanism. METHODS: Forty patients who were scheduled to have gynecological and urological procedures under general anesthesia were randomly divided into an observation group and a control group, 20 cases in each group. The patients in the observation group were treated with TEAS (dilatational wave, 2 Hz/100 Hz) at Yingxiang (LI 20) and Yintang (GV 29) 10 min before anesthesia induction until the end of operation; the patients in the control group received general anesthesia directly. The changes of mean arterial pressure (MAP), heart rate (HR) and blood oxygen saturation (SpO2) were recorded before treatment, 30 min after operation and at the end of operation; smell identification score was measured by Connecticut Chemosensory Clinical Research Center (CCCRC) olfactory test before treatment (T0) and when Aldrete recovery score reached 10 points at the end of anesthesia (T1); the concentration of melatonin in plasma was measured by ELISA method in the two groups. RESULTS: The between-group differences and within-group differences of MAP, HR and SpO2 were not significant at each time point (P>0.05). Compared with T0, the score of smell identification and plasma concentration of melatonin were not significantly different at T1 in the observation group (P>0.05), however, the score of smell identification and plasma concentration of melatonin were reduced in the control group (P<0.05). At T1, the score of smell identification and plasma concentration of melatonin in the observation group were higher than those in the control group (P<0.05). CONCLUSION: TEAS could improve the postoperative olfactory memory disorder in patients with general anesthesia of sevoflurane, and its mechanism may be related to the increase of plasma concentration of melatonin.
