Comparison study of student’s learning achievement between the flip classroom with and without group management

บทความในวารสาร

ผู้เขียน/บรรณาธิการ

กลุ่มสาขาการวิจัยเชิงกลยุทธ์

ไม่พบข้อมูลที่เกี่ยวข้อง

รายละเอียดสำหรับงานพิมพ์

รายชื่อผู้แต่ง: Jitjumnong K., Suksakulchai S.

ผู้เผยแพร่: Institute of Electrical and Electronics Engineers

ปีที่เผยแพร่ (ค.ศ.): 2019

วารสาร: IEEE Transactions on Plasma Science (0093-3813)

Volume number: 9

Issue number: 12

หน้าแรก: 904

หน้าสุดท้าย: 908

จำนวนหน้า: 5

นอก: 0093-3813

eISSN: 1939-9375

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063957020&doi=10.1109%2fTPS.2019.2895235&partnerID=40&md5=7c8ff138b7aa7ae93f7b0db895abc62c

ภาษา: English-Great Britain (EN-GB)

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บทคัดย่อ

Vacuum circuit breakers have an issue of instability arc current and chopping phenomena when the current is cut off from the circuit. To clarify the effect of the instability low-current vacuum arc for circuit breaker development, the instability mechanism of low-current vacuum arc for various parameters was proposed to verify consequent affecting circuit breaker capacity in this paper. This paper used the cathode spot model neglect the transition region between the collisionless sheath and collisional plasma region. The eight equations were used for solving the dependent variable of plasma parameters for both silver and copper electrode materials. The low ionization was supposed in the cathode spot model. The results showed that the changes in the work function and ion current fraction at ambient temperature did not have the main influence on the arc stability limit current both in the silver electrode and copper electrode. On the contrary, the changes in the heat conductivity at ambient temperature affecting the arc stability limit current significantly both in the silver and copper electrodes. Furthermore, the results were found out that the cathode spot can be confirmed unstable current phenomena when the current below 19 A for copper cathode and below 19.4 A for the silver cathode. These phenomena can be explained that the reversed electrons flow from the plasma side to sheath region affecting the electric field at cathode spot become negative zone; thus, the starting noise on the current trace appears before chopping current. ฉ 1973-2012 IEEE.

คำสำคัญ

Arc current, cathode spot, instability phenomena