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Libin Wang,Weiqi Luo,Xiuxiu Sun,Chunlu Qian 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.6
Flavor quality is import for determining consumer perception and acceptance of tomato products. In this study, ‘Fendou’tomato fruit were harvested at six ripening stages and sampled to investigate the development of fl avor-relevant compoundsduring vine ripening. Results showed that upon the initiation of ripening there was an increase in respiration rate and concomitantethylene evolution that was associated with increased membrane permeability. In accordance with these physiologicalchanges, fl avor-relevant compounds demonstrated diff erent expression patterns as fruit ripened, which contributedto ‘red-ripe’ fl avor characteristics of red-ripe fruit. Based on correlation analysis between ethylene evolution and the fl avorrelevantcompounds during ‘Fendou’ tomato ripening and the other researchers’ reports, the activation of System 2-dependentautocatalytic ethylene production plays an important role in the development of most fl avor-relevant compounds duringtomato vine ripening. Overall, our results suggested that most fl avor-relevant compounds that accumulated the most duringtomato fruit ripening at red stage could be under ethylene regulation and were among the most important contributors tothe ‘red-ripe’ fl avor. Due to the development of these compounds, the fl avor quality at late ripening stages is diff erent fromthat of fruit at early ripening stages.
The Dynamic Characteristics of a Small Hydraulic Poppet Safety Relief Valve
Yong Sang,Xudong Wang,Weiqi Sun 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.1
Hydraulic poppet pressure relief valve, which has the advantages of fast response and good sealing performance, is extensively used in the hydraulic industry. In this paper, a two-dimensional axisymmetric geometry model of the hydraulic poppet safety relief valve with a small size is established. Dynamic mesh, along with UDF in FLUENT software, is used in this study. The dynamic characteristics of a hydraulic poppet safety relief valve using CFD are investigated under different conditions. For incompressible hydraulic oil, a sharp force rise and collapse caused by a redirection of the fluid flow due to inertia forces is depicted, and the variation of the poppet motion under the influence of the back pressure is analyzed based on the flow information. The dynamic behavior of the hydraulic poppet relief valve under different set pressure is investigated. In the end, a numerical study on the instability of the poppet relief valve supplying a constant volumetric flow rate is performed, and the chatter frequency is obtained.