This study attempts to manufacture a Ni-Cr-Al-Y coating layer using a kinetic spray process and investigates the microstructure and physical properties of the manufactured layer. The Ni-22Cr-10Al-1Y (wt.%) composition powder is used, and it has a spherical shape with an average diameter of 23.7 μm. Cu plate is used as the substrate. Optical microscope, X-ray diffraction, scanning electron microscope and Vickers hardness test are carried out to characterize the macroscopic properties of the coating layer. Furthermore, the coating layer underwent vacuum heat treatment at temperatures of 400˚C and 600˚C for 1 hour to check the effect of heat treatment temperature on the properties. The manufactured coating layer is 1.5 mm thick, and featured identical phases to those found in the powder. The porosity of the coating layer is measured at 2.99%, and the hardness is obtained at 490.57 Hv. The layer shows reduced porosity as heat treatment temperature increased, and hardness is reduced at 400˚C but shows a slight increase at 600˚C. Based on the findings described above, this study also discusses possible manufacturing methods for a Ni-Cr-Al-Y coating layer using the kinetic spray process.

We report molecular line observations of CO(1-0), 13CO(1−0), CS(2-1), and HCN(1-0) with SRAO 6m telescope toward L1014-IRS which is thought to be a very faint infrared source embedded in previously known 'starless' core L1014. The CO(1-0) observations find several components with different velocities along the line of sight of L1014, 4kms−1 and between 40∼50kms−1. We find a parsec scale CO molecular outflow at the 4kms−1 component for the first time the direction of which is coincident with that of the small scale ( ∼500pc) outflow previously found. Although the observation is not covered for whole area of the outflow, the size of the molecular outflow seems not very inconsistent with the expected age of L1014-IRS. More accurate size and shape of the molecular outflow from L1014-IRS will be determined from the full coverage mapping in CO over the outflow region in very near future.

We compare the results of the surveys of starless cores performed with CS (2-1) and (3-2) lines to study inward motions in the cores. The velocity shifts of the CS(3-2) and (2-1) lines with respect to N2H+ are found to correlate well with each other and to have similar number distributions, implying that, in many cores, systematic inward motions of gaseous material may occur over a range of density of at least a factor ~ 4. Fits of the CS spectra to a 2-layer radiative transfer model in ten infall candidates suggest that the median effective line-of-sight speed of the inward-moving gas is ~ 0.07 km s-l for CS (3-2) and ~ 0.04 km s-l for CS(2-1). Considering that the optical depth obtained from the fits is usually smaller in CS(3-2) than in (2-1) line, this may indicate that CS(3-2) usually traces inner, denser gas with greater inward motions than CS(2-1) implying that many of the infall candidates have faster infall toward the center. However, this conclusion may not be representative of all starless core infall candidates, due to the statistically small number analyzed here. Further line observations will be useful to test this conclusion.

A spectral line survey is performed from 159.7 to 164.7 GHz toward Orion-KL, as an extension of our previous line survey from 138.3 to 150.7 GHz with the same 14 m radio telescope of Taeduk Radio Astronomy Observatory. Typical system temperatures were 260 - 1000 K to achieve a sensitivity of about 0.02 - 0.04 K in TA unit. A total of 63 line spectra are detected in this survey. Among them, 54 lines lines are found to be the first detections towards an astronomical source and only 9 spectral lines have been previously identified from other observations. Forty-eight of 54 lines are believed to be from the known transitions of the known molecules, while 6 lines are 'unidentified'. All detected lines are found to be from a total of 10 molecular species and their isotopic variants. The molecular species with most numerous detected transitions are HCOOCH3 (22), followed by CH3OCH3 (7), C2H5CN (7), and SO2 (6). The LTE rotation diagram analysis using all homogeneous data with those from previous survey gives more reliable determination of physical quantities. The derived values of the rotation temperatures and column densities for HCOOCH3, CH3OCH3, and SO2 are are 75 ~ 197 K and 1.5 ~ 18 × 10 15 cm -2, respectively.

Background : The organic matter content of land clearing or soil brought from an other place is very low, less than 0.5%. However, the organic matter content of natural habitat soil and leader farmhouse soil was two to three times higher than that of general farmhouse soil. As a result, the yield of Gastrodia elata was higher than that of general farmhouse. Therefore, this experiment was carried out to investigate the yield of G. elata according to the application of green manure crops (GMCs). Methods and Results : This experiment was carried out in a soil with organic matter content of 0.5% in rain shelter greenhouse. The kind of GMCs are corn, Sudan grass, sorghum and oats, and the throughputs per 10 a were 2,000 ㎏, 2,200 ㎏, 1,500 ㎏ and 700 ㎏ of each. The soil preparation was carried out after treated of GMCs at least one month before G. elata was formally planted. As the results of these experiment, organic matter content in soils increased 4 - 5 times compared with before treatment. As a result, the yield of G. elata increased by 21 - 41% in all treatments of GMCs. In addition, there was 2 - 5% more G. elata of good merchantable quality. However, the soil temperature in the summer season period of 2016 (7.1 - 8.31) was 1.2 - 1.6℃ higher than the previous year. The day when the outside temperature was above 30℃ was 41 days. It doubled from the previous year. Soil moisture content showed similar tendency according to treatments. As a result, 20 - 30% of high temperature damage and 20 - 50% of putrefaction occurred, and the total yield also decreased by 20 - 30% compared to normal year. Conclusion : In conclusion, some organic matter is needed for cultivation of G. elata. Therefore, it is considered that it would be better to keep the organic matter content at 2 - 3% when the destination are managed, and to use corn or Sudan grass as the GMCs.