• Title/Summary/Keyword: Side scuttle

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An experimental study for the evaluation of airborne sound insulation performance of the small window (소형 창문의 차음 성능 평가에 관한 실험적 고찰)

  • Choi, Dool;Moon, Soon-Sung;Goo, Hee-Mo;Kim, Hang;Park, Hyeon Ku
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.1-1
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    • 2014
  • Side scuttle in the shipboard windows is used in a smaller size in order to prevent damage to the glass. This shipboard windows should have high sound insulation performance (More than $R_w$ 53 dB) according to norsok standards. However, side scuttle having a small size and high sound insulation material is difficult to measure exact result without a suitable filler wall. In this study, the test was conducted according to the number of changes in the small window. As a result, before starting the test should be conducted to the selection of the suitable filler wall or secure a specimen area.

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Development of Central Nervous System in Scuttle Fly (Scuttle Fly에서 중추신경계 발달 연구)

  • Park, Ho-Hyun;Park, Mi-Suk;Na, Kil-Ju
    • Korean Journal of Clinical Laboratory Science
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    • v.50 no.3
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    • pp.284-288
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    • 2018
  • The scuttle fly central nervous system (CNS) is unobservable during egg and larvae instar stage 1. During days 2~3 of larvae instar stage 2, the left and right hemisphere of the brain can be observed. Below the brain, the subesophageal ganglion (SOG) connects to the ventral nerve cord (VNC). During days 3~5 of larvae instar stage 3, the CNS enlarged slightly with no other changes. During days 1~3 of the pupal stage the CNS moved to the head with no distinguishable changes from the previous stage. During days 4~6 of the pupal stage, the left and right hemisphere of the brain had fused into one mass and the optic lobe (OL) located on the side of the brain completed its development. During days 7~9 of the pupal stage, the OL began to show eyeball pigment. The SOG was connected to the brain and the VNC began to separate, which was accompanied by an increase in nerve fibers. During days 10~12 of the pupal stage, the brain of the CNS and VNC was clearly distinguished and the brown pigmentation of OL became darker. During days 13~15 days of the pupal stage, the separated brain and VNC became connected by thin nerve fiber. The VNC began to separate into two with a greater increase in nerve fibers. The adult fly showed similar features to the previous stage, but the brain was located in the head and the VNC in the chest.