• Journal of Animal Science and Technology
• /
• v.51 no.3
• /
• pp.225-230
• /
• 2009

This experiment was carried out to investigate the effects of ruminally inserted artificial fiber (RIAF; polymerized fibrous implements) on growth performance, feed intake and carcass characteristics of Hanwoo steers. Thirty six steers averaging $368.3\pm20.3kg$ were randomly assigned into three groups: control group, the ruminal insertion of three pieces (T1), and five pieces (T2) of RIAF. Average daily gain, feed intakes and conversions among treatments were similar. Numbers of rumen villi were higher in RIAF treatment (T1 and T2) groups than control group, but they were not significant (p>0.05). The length of villi were significantly longer in T2 than control group (p<0.05). Fecal weight tended to decrease in T1 compared with the control group (p>0.05). There was no differences on carcass traits inc1uding longissmus muscle area, back fat thickness, marbling score, meat color, and fat color among treatments.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.2
• /
• pp.41.1-41.1
• /
• 2016

The Galactic center, Sagittarius A* (Sgr A*), is the closest supermassive black hole and emits synchrotron radiation. It provides great opportunity to study the origin of mm/sub-mm emission. Currently, two competing models have been suggested as a jet base and a radiatively inecient accretion flow (RIAF). To unveil the properties, the extremely high resolution(${\sim}10{\mu}as$) corresponding to the projected Schwarzschild radius of ~0.1AU is necessary. With KVN, a jet model can be tested by multi- frequency simultaneous observations because the optically thick surface in a jet (i.e. radio core) moves toward the center at a higher frequency. We conducted 8 observations with KVN at 43/86GHz in 2015, and found that the measured positional shift to the reference calibrator, J1744-3116, was ~0.3 mas to the south of Sgr A* using the source frequency phase referencing (SFPR) at Q/W bands for the first time. With the result, in the future, we will attempt to measure the variation of source position shifts that can constrain the direction of approaching jets and the variability of black hole activity of Sgr A*.