본 연구는 국내에서 실내 관상용으로 많이 활용되는 스킨답 서스의 실내재배 시 적정 인공광원, 수경재배 전기전도도 농 도 및 용토를 선발하기 위하여 수행하였다. 실내재배 시 인공 광원은 형광등, 적청 LED, 백색 LED로 처리하였다. 수경재배 시 양액 농도는 EC 1.2, 1.6, 2.0ds·m-1 수준으로 하였고, 재 배용토는 제올라이트, 코코피트, 펄라이트, 황토볼 4가지로 달리하였다. 스킨답서스의 실내 재배 시 줄기 길이는 형광등 과 적청 LED 처리보다 백색 LED 처리에서 길어졌다. 잎의 크기는 적청 LED 처리에서 형광등과 백색 LED 처리보다 커 지는 경향이었다. 엽록소 지수값은 백색 LED>적청 LED>형광 등 순으로 높았다. 수경재배 시 스킨답서스의 줄기길이는 EC 농도가 높아질수록 길어지는 경향이었고, 용토별로 비교하면 제올라이트와 코코피트에서 높은 경향이었다. 엽록소 지수값 도 EC 농도와 비례하여 높아졌고, 용토별로는 제올라이트와 코코피트에서 높았다. 스킨답서스의 생체중도 EC 농도가 높 을수록 높았고, 제올라이트와 코코피트에 높은 경향이었다. 상기 결과들을 종합할 때, 스킨답서스의 NFT를 이용한 실내 재배 시 적정 인공광원으로는 백색 LED를, 수경재배 양액의 농도는 EC 1.6∼2.0ds·m-1를, 그리고 NFT 용토는 제올라이 트나 코코피트가 적합하다는 것을 알 수 있었다.

KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

The main goal of the Korean VLBI Network Calibrator Survey (KVNCS) is to expand the VLBI calibrators catalog for KVN, KaVA(KVN and VERA Array), EAVN(East-Asian VLBINetwork), and other extended regions. The secondKVNCS (KVNCS2) aimed to detect VLBI fringes of new candidates for calibrators in the K band. Out of the 1533 sources whose single-dish flux density in the K band was measured with KVN telescopes (Lee et al. 2017), 556 sources were observed with KVN in the K band. KVNCS2 confirmed the detection of VLBI fringes of 424 calibrator candidates over a single baseline. All detected sources had a high Signal-to-Noise Ratio (SNR) of >25. Finally, KVNCS2 confirmed 347 new candidates as VLBI calibrators in the K band, resulting in a 5% increase in the sky coverage compared to previous studies. The spatial distribution was quasi-uniform across the observable region (Dec. > −32.5◦). In addition, the possibility as calibrator candidates for the detected sources was checked, using an analysis of the flux-flux relationship. Ultimately, the KVNCS catalog will not only become the VLBI calibrator list but is also useful as a database of compact radio sources for astronomical studies.

Intermuscular fat is essential for enhancing the flavor and texture of cultured meat. Mesenchymal stem cells derived from intermuscular adipose tissues are a source of intermuscular fat. Therefore, as a step towards developing a platform to derive intermuscular fat from mesenchymal stem cells (MSCs) for insertion between myofibrils in cultured beef, an advanced protocol of intermuscular adipose tissue dissociation effective to the isolation of MSCs from intermuscular adipose tissues was developed in cattle. To accomplish this, physical steps were added to the enzymatic dissociation of intermuscular adipose tissues, and the MSCs were established from primary cells dissociated with physical step-free and step-added enzymatic dissociation protocols. The application of a physical step (intensive shaking up) at 5 minutes intervals during enzymatic dissociation resulted in the greatest number of primary cells derived from intermuscular adipose tissues, showed effective formation of colony forming units-fibroblasts (CFU-Fs) from the retrieved primary cells, and generated MSCs with no increase in doubling time. Thus, this protocol will contribute to the stable supply of good quality adipose-derived mesenchymal stem cells (ADMSCs) as a fat source for the production of marbled cultured beef.

The effect of Li2O addition on precipitation behavior of uranium in LiCl-KCl-UCl3 has been investigated in this study. 99.99% LiCl-KCl eutectic salt is mixed with 10wt% UCl3 chips at 550°C in the Pyrex tube in argon atmosphere glove box, with 10 ppm O2 and 1 ppm H2O. Then, Li2O chunks are added in mixed LiCl-KCl-UCl3 and the system has been cooled down to room temperature for 10 hours to form enough UO2 particles in the salt. The solid salt has been taken out from the glove box, and cut into three sections (top, middle and bottom) by low-speed saw for further microscopic analysis. Three pieces of solid salt are dissolved in deionized water at room temperature and the solution is filtered by a filter paper to collect non-dissolved particles. The filter paper with particles is baked in vacuum oven at 120°C for 6 hours to evaporate remaining moisture from the filter paper. Further analysis was performed for the powder remaining on the filter paper, and periphery of the powder (cake) on the filter paper. Scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), and X-ray powder diffraction (XRD) are adopted to analysis the characteristic of the particles. From SEM analysis, the powders are consisted of small particles which have 5 to 10 m diameter, and EDS analysis shows they are likely UO2 with 23 at. % of uranium and 77 at. % oxygen. Cake is also analyzed by SEM and EDS, and needle like structures are widely observed on the particle. The length of needle is distributed from 5 to 20 m, and it has 6 to 10 at. % of chlorine, which are not fully dissolved into deionized water at room temperature. From XRD analysis, the particles show the peak position of UO2, and the result is well matched with the SEM-EDS results. We are planning to add more Li2O in the system for fully reacting uranium in UCl3, and compare the results to find the effect of Li2O concentration on UO2 precipitation.