• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.96.1-96.1
• /
• 2014

The rotation of asteroids can help reveal not only the fundamental characteristics of asteroids but also the origin and evolution of our Solar System. From the photometric observations for NEA 162173 (1999 JU3) and Maria family asteroids using 0.5 m- to 2 m- class telescopes at 10 observatories in the northern hemisphere, I obtained a total of 260 lightcurves for 97 asteroids and derived synodic rotational periods for 51 objects, including newly obtained periods of 34 asteroids. For the sake of efficiency, I developed an observation scheduler, SMART (Scheduler for Measuring Asteroid RoTation) and a photometric analysis software subsystem, ASAP (Asteroid Spin Analysis Package). Based on the lightcurve analysis of NEA 162173 (1999 JU3) and Maria family asteroids, 1) I present the rotational and observational characteristics of 1999 JU3 and provided the Hayabusa-2 Science team with the information on pole orientations, 2) I investigated correlations among rotational periods, amplitudes of lightcurves, and sizes, and conclude that the rotational properties of old-type family asteroids have been changed considerably by the YORP effect. 3) Finally, I found the Yarkovsky footprints on the Maria asteroid family and estimated that approximately 37 to 75 Maria family asteroids larger than 1 km have entered the near-Earth space every 100 Myr. This study should reveal the collisional history and transport route of the members from the resonance region to the near Earth space, for the first time.

• Textile Coloration and Finishing
• /
• v.32 no.1
• /
• pp.19-26
• /
• 2020

The previous study reported that the quaternary copolymer of MMA, BA, MAA, and NEA was expected to be a good monomer composition for a binder polymer with good rubbing fastness for digital textile printing(DTP) pigment ink. However, the rubbing fastness of the dyed fabric with the quaternary copolymer binder containing pigment ink is not enough to be commercially used. Therefore, this study aims to optimize MMA:BA:MAA:NEA composition for improved rubbing fastness. And the binder polymer with various MMA:BA:MAA:NEA compositions were synthesized using miniemulsion polymerization. The particle size, viscosity, molecular weight, and Tg of the synthesized binder were evaluated. And the color strength and rubbing fastness of the black pigment ink dyed cotton fabrics with the prepared binders were also evaluated. Then, the stiffness of undyed and dyed cotton fabrics were evaluated to investigate the changes in touch as the binder structure changes.

• Nuclear industry
• /
• v.7 no.7 s.53
• /
• pp.28-31
• /
• 1987

• Nuclear industry
• /
• v.6 no.10 s.44
• /
• pp.75-76
• /
• 1986

• Nuclear industry
• /
• v.7 no.5 s.51
• /
• pp.88-90
• /
• 1987

장수명화가 자본비를 상당히 낮추는데 연결이 되면 원자력발전의 경제성 향상의 하나의 방향이 되는 것으로 주목되고 있다.

• Nuclear industry
• /
• v.18 no.12 s.190
• /
• pp.46-53
• /
• 1998

• Nuclear industry
• /
• v.35 no.8
• /
• pp.68-71
• /
• 2015

• Proceedings of the Korean Nuclear Society Conference
• /
• 2001.05a
• /
• pp.552.1-552
• /
• 2001

• Nuclear industry
• /
• v.25 no.4 s.266
• /
• pp.4-7
• /
• 2005

• The Korean Journal of Ceramics
• /
• v.2 no.4
• /
• pp.193-196
• /
• 1996

A new type of electron emitter device of chemical-vapor-deposited diamond thin film is proposed. The device is a diode of metal-insulator-insulator-semiconductor (MIS) structure consisting of an intrinsic polycrystalline diamond film as the insulator, an aluminium electrode on one side, and hydrogenated diamond surface on the other side as the p-type semconductor with negative electron affinity (NEA). Electrons will be injected and/or excited to the conduction band of intrinsic diamond layer to be emitted from the hydrogenated diamond surface of NEA.