We report the performance of the 13.7-meter Taeduk Radio Astronomy Observatory (TRAO) radio telescope. The telescope has been equipped with a new receiver, SEQUOIA-TRAO, a new backend system, FFT2G, and a new VxWorks operating system. The receiver system features a 16-pixel focal plane array using high-performance MMIC preamplifiers; it shows very low system noise levels, with system noise temperatures from 150 K to 450 K at frequencies from 86 to 115 GHz. With the new backend system, we can simultaneously obtain 32 spectra, each with a velocity coverage of 163 km s−1 and a resolution of 0.04 km s−1 at 115 GHz. The new operating system, VxWorks, has successfully handled the LMTMC-TRAO observing software. The main observing method is the on-the-fly (OTF) mapping mode; a position-switching mode is available for small-area observations. Remote observing is provided. The antenna surface has been newly adjusted using digital photogrammetry, achieving a rms surface accuracy better than 130 µm. The pointing uncertainty is found to be less than 5'' over the entire sky. We tested the new receiver system with multi-frequency observations in OTF mode. The aperture efficiencies are 43±1%, 42±1%, 37±1%, and 33±1%, the beam efficiencies are 45±2%, 48±2%, 46±2%, and 41±2% at 86, 98, 110, and 115 GHz, respectively.

폴리아마이드 역삼투 분리막은 우수한 분리성능(염제거율, 수투과도)으로 인해, 해수담수화 공정의 핵심소재로 널리 사용되어오고 있다. 하지만, 해수내 존재하는 오염원에 의해 막표면이 오염(파울링)되어 성능이 저하되는 문제점을 가지고 있어, 분리막의 내오염성을 향상시키기 위한 많은 연구가 이루어져 왔다. 기존 연구는 주로 분리막 표면을 화학적으로 개질하는 방식에 의존하였으나, 장기간 내오염성이 유지되지 못하는 단점을 가지고 있다. 최근 분리막의 표면구조를 제어하여 내오염 특성을 부여하려는 연구가 시도되어 왔다. 본 연구에서는 새로운 분리막 표면구조 제어기술을 활용하여, 내오염특성이 우수한 생체의 표면구조를 모사한 역삼투 분리막을 제조하고, 우수한 내오염성을 구현하였다.

We map two molecular clouds located in the exact anticenter region emitting in the (J = 1-0) transition of 12CO and 13CO using the 3-mm SIS mixer receiver on the 14-m radio telescope at Taeduk Radio Astronomy Observatory. The target clouds with anomalous velocities of VLSR ~ - 20 km s-1 are distinguished from other clouds in this direction. In addition, they are located in the interarm region between the Orion Arm and the Perseus Arm. Sizes of the clouds are estimated to be about 8.6 and 10.8 pc, respectively. The total mass is estimated to be about 4 x 103 M⊙ using CO luminosity of the clouds. Several cores are detected, but no sign of star formation is found according to the IRAS point sources. Their larger linewidths, anomalous velocities, and their location at the interarm region make these clouds more distinguished, though their physical properties are similar to the dark clouds in the solar neighborhood in terms of mass and size.