• Title/Summary/Keyword: weightlessness

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Investigation of Packaging of Fresh Jujube (Zizyphus jujuba) on Quality during Storage (농가에서 활용가능한 생대추의 저장조건 연구)

  • Chung, Hyun-Jung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.8
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    • pp.1296-1302
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    • 2013
  • The quality of fresh jujube (Zizyphus jujuba) fruit rapidly declines in the postharvest stage and thus the effective storage conditions for agricultural warehouses were investigated in this study. Fresh jujubes (~10 kg) were stored using five different storage methods: plastic box without further packaging as a control (C-PL), plastic box with hanji packaging (H-PL), plastic box with functional film packaging (F-PL), cardboard box with hanji packaging (H-CB), and cardboard box with functional film packaging (F-CB). The storage boxes were stored in a refrigerator ($0^{\circ}C$ and 80~90% RH), equipped with an ethylene gas scavenging device for 9 weeks and then the quality characteristics were analyzed. The control storage conditions of jujubes showed a substantial decline in quality with decreases in moisture content, hardness, and sugar content as well as increases in decay ratio and redness. Among the tested storage conditions, F-CB was most effective in terms of maintaining the quality of jujube fruit while maintaining firmness, weightlessness, ripening degree from redness and visible appearance. In conclusion, effective storage and packaging conditions during storage enabled maintenance of fruit quality of jujubes for 9 weeks.

Effects of Cognitive Conflicts before Confronting Anomalous Phenomena on Middle School Students' Conceptual Changes in Physics (불일치 현상 대면 전의 인지갈등이 중학생들의 물리 개념변화에 미치는 영향)

  • Kwon, Mi-Rang;Kim, Ji-Na;Kim, Jung-Bog;Kwon, Jae-Sool
    • Journal of The Korean Association For Science Education
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    • v.29 no.8
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    • pp.886-897
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    • 2009
  • One of useful strategies to change students' misconceptions into scientific conceptions in physics is the cognitive conflict strategy, the main point of which is to arouse cognitive conflicts by presenting anomalous phenomena to students. However, it has been reported that students experienced cognitive conflicts while expecting or reasoning results of an experiment before confronting an anomalous phenomenon. Therefore, we have examined how much students' cognitive conflicts were aroused before presenting an anomalous phenomenon. Then, we investigated the effects of the cognitive conflicts aroused prior to the students' confrontation with an anomalous phenomenon, both on the cognitive conflicts occurring after the students' confrontation with it, and on the students' conceptual changes. This study was performed during regular classes about light-source and weightlessness concepts. Subjects from two different middle schools in Pusan took part in the study. Preconceptions, degrees of cognitive conflicts before and after confronting anomalies, and postconceptions were checked during the classes. Then, delayed postconceptions were also checked in 3 weeks. As a result, the degree of cognitive conflicts before confronting an anomaly was as much as the degree of cognitive conflicts after it. There was significant correlation between both conflicts. Also the degree of cognitive conflicts before confronting an anomaly was a main factor in predicting the conceptual changes, while both conflicts had been related separately to the conceptual changes.