The diaphragm is an important part because it plays an important role in changing the flow direction of hightemperature and high-pressure steam in the steam turbine. Because it is subjected to high pressure by high temperature steam, there should be great concerns about breakage of parts, runouts due to vibration by rotating parts, and deformation due to creep effect and fatigue breakage due to long-term use in high temperature environments. In order to ensure the safety of turbine components in such a harsh environment, structural analysis should be prioritized prior to manufacturing prototypes. In this study, in order to verify the design stability of the diaphragm, physical safety is checked through static analysis, vibration analysis, and fatigue analysis, and the fatigue life is predicted. The total deformation, equivalent stress, and strain are determined by static analysis, and the stress and total deformation by the harmonic response are obtained through vibration analysis, and the stability is judged by comparing it with the characteristic value. We intend to verify the safety of the design and propose a complementary diaphragm design.

대형 유조선에서 유류의 선적이나 하역에 사용되는 장치인 COPT (Cargo Oil Pump Turbine) 가 매우 큰 형태이므로 이 터빈을 회전시키는 장치가 Rotor disc로서, 내부에 stator ring이 장착되어 있고 이 ring에는 많은 turbine blade가 riveting 방법에 의해 체결되어 있다. riveting 은 재래식 가공 방법으로서 정밀도와 작업자의 근 골격계 직업병 등 많은 문제점을 포함하고 있다. 이러한 문제를 해결하기 위해 riveting 체결방법을 조립방법으로 전환하여 링의 조립정밀 도를 향상하고 stator의 수명을 연장시킬 수 있다. 많은 turbine blade가 링의 중심점을 기준으로 원주상에 배열되어 있는 형태로서 조립을 위한 구조개선을 필요로 한다. 이런 목적을 달성 하기 위해서는 ring 구조를 결구 방식으로 변경하고 조립 후 COPT에 적용하였을 때 안전성이 보장되어야 한다. Stator 링의 모델링과 구조안전성에 대한 검증은 상용 software를 이용하여 결과를 도출한다.

원전 해체 공정 중 절단 및 용융작업에서 발생되는 방사성 에어로졸은 작업종사자의 호흡을 통해 내부 피폭을 유발하게 된다. 이에 따라 해체 중 방사성 에어로졸로 인한 작업종사자의 내부피폭 평가가 필요한 실정이다. 정확한 내부피폭평가를 위해서는 작업종사자의 작업환경 실측값이 필요하지만 실측에 어려움이 있을 시에는 국제방사선방호위원회(ICRP)에서 제시하는 섭취량 분율 및 입자 크기 등의 권고 값을 통해 내부피폭선량을 추정할 수 있다. 본 논문에서는 입자 크기의 선정은 ICRP에서 권고하는 작업종사자의 고려 입자 크기인 5 μm을 적용하였다. 발생량의 경우, 불가리아의 Kozloduy 부지 내의 용융시설에서 발생 된 에어로졸의 포집량 데이터를 이용하여 섭취량을 산정하였다. 또한 이를 이용해 작업종사자의 체내 및 배설물에서의 방사능 수치를 계산하고 BiDAS 전산코드를 통해 내부피폭 평가를 수행하였다. Type M이 0.0341 mSv, Type S가 0.0909 mSv로 두 흡수 형태 각각 국내 연간 선량 한도의 0.17%, 0.45% 수준을 나타내었다.

Rotor disc (로터 디스크)는 중대형 유조선에서 유류를 하역하는 장치인 COPT (Cargo Oil Pump Turbine)의 터빈을 고속으로 회전시키는 핵심 부품이다. 이 rotor disc는 중심 shaft에 여러 개의 turbine을 원주상으로 배열하고 체결하여 제작한다. 현재의 제작 방법으로는 turbine blade를 배열하고 shroud 덮개로 연결하여 riveting 방식으로 체결한다. 이런 고전적인 방법은 blade pitch의 불균일은 물론 작업 시 오류로 인해 blade에 손상이 가는 경우가 있다. 이러한 단점을 해결하기 위해서는 조립식의 rotor disc를 설계하여 제작방식을 변경해야 한다. 설계뿐만 아니라 조립식의 disc가 구조적으로 안정한지를 평가해야 한다. 본 논문은 blade의 설계와 이를 조립하였을 때에 구조안전성을 평가하기 위해 구조 해석하여 그 안전성을 검증 한다.

Modern manufacturing industries is to produce both precise and robust mechanical parts without failure while they are in service. In order to prevent a part failure for its lifetime, a mechanical design for a part should be examined on a basis of mechanical simulation. A nozzle plate, being a key part in steam engines, changes flow directions of steam in a turbine used in power plant. This paper is to the design and test for part safety and durability. Currently, nozzle plates are fabricated by welding nozzles to their plates. Welding causes some defects on the used materials while they are being manufactured. Another major defect is un-even pitches between welded nozzles. Welding causes phase changes because of high melting temperature of metal. This leads to decay on the welding spots, which weakens their structural strength and then, may lead to early damages on mechanical structures. This research proposes assembly-typed nozzle plate without welding. From the beginning, nozzle and plate are designed for insertion-typed assembly. Nozzle head and foot are designed in accordance with the grooves on outer ring and inner ring of a plate to make mating surfaces. Then the nozzle plate should be proved for structural and fatigue safety before they are put in manufacturing. This research adopts commercial softwares for modeling and mechanical simulation. The test result shows that the design with smaller mating area and deeper insertion produces higher safety in terms of structure and durability. From the conclusion, this paper proposes the assembly-typed nozzle plate to replace the welding typed.

질산, 불산 및 과염소산을 사용하여 플루토늄 옥사이드 을 녹여 Pu 기준용액을 제조한후 UV-Visible-Near IR 분광기를 이용하여 Pu 흡수 스펙트럼 특성을 관찰하였다. 산성, 중성 및 알칼리 매질에서 Pu(III), Pu(IV) 및 Pu(VI)에 대한 분광학적 특성을 조사하였다. 또한 알칼리 및 산 농도 증가에 따른 Pu(VI) 흡수 스펙트럼에 대한 특성 피크 세기 및 위치를 관찰하였다. 염산 및 수산화나트륨 매질에서 환원제 첨가에 따른 Pu(VI) 산화수 변화를 측정하였다.

Background : Wild-simulated ginseng (WSG, Panax ginseng C. A. Meyer) in Korea which depends on an artificial forest growth method. Methods and Results : WSG samples were collected from 8 different regions in Korea in October, 2017, and these were analyzed by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS) using optimized analytical methods to compare the metabolite patterns to cultivated regions. Furthermore, their metabolite compositions differed according to individual plant samples. The metabolite profiling data were processed by multi-variate statistical analyses such as PCA and PLS-DA to determine the differences among geographical origins. To identify significant metabolites according to regional variances of WSG, more sophisticated multi-variate statistical analyses such as metabolite selection should be performed. Conclusion : This metabolomics approach can also be applied to evaluate the overall quality of WSG, as well as to discriminate the cultivars for the medicinal plant industry.

Background : A major medicinal plant, Angelica gigas Nakai, have using root parts and mainly cultivated the cool temperature region of high alpine as wild type in the northeast of China, Japan and Korea. The roots of grow it’s rapidly form August, and harvested from October to November. This study performed that the growth characteristics on soil mulching vegetation cultivation field of 300 m altitude of under Larix leptolepis (S. et Z.) Gordon in Bonghwa-gun, Gyeongsangbuk-do. Methods and Results : After one-year seeding of the same size (7 - 8 ㎜) were transplanted in three types soil mulching of cultivation (plastic, straw and non-mulching) overground growth surveyed in three times (May to August), To confirm of soil condition compared the average. Soil condition of plot were observed to pH 5.56, OM 3.22%, T-N 017%, and growth increment were higher observed to that straw and non-mulching then plastic mulching of such as plant length 46.8 ㎝, stem diameter 5.9 ㎜, leaf length 24.4 ㎝ and width 28.9 ㎝, number of radical leaf 3.1. But from August, when the average temperature was high, the growth characteristics such as plant length, petiole Length, leaf length and width were reversed compared to those of plastic and non-mulching. Conclusion : In case of cultivation of A. gigas in the environmental conditions of mountainous area, considering the growth from August to October when the roots growth bigger, It suggested that strew mulching is better than plastic and non-mulching, would be done through further research on underground growth characteristics of A. gigas according to harvesting time confirmed the relationship to the growth characteristics of A. gigas according to environmental conditions and soil mulching mountainous plantations.

Background : Wild-simulated ginseng (WSG, panax ginseng C. A. Meyer) is known to be grown in high altitudes with a climate of cool, well ventilated and fertile humid forests. In this study, the effects of altitude and soil characteristics on the growth of WSG were investigated. Methods and Results : The seeds were planted on designated line, and the altitude was set at 600 highland and 300 highland. At each highland soil characteristics and forest condition were investigated also Hobo (HOBO U30 Werther station) was set up to measure the microclimate in the site. Experiments were conducted in each highland to determine the difference in the growth of WSG according to the soil condition. Growth characteristics of undergrowth, such as root thickness and length also upper growth such as stem length and thickness were measured. As a result of the soil characteristics survey, the value of available phosphorus was found to be 256.7 ㎎/㎏ at 300 highlands. On the other hand, in 600 highland, available phosphorus was 29.59 ㎎/㎏, which showed big difference. Conclusion : Overall, the cation exchange capacity was higher than the 600 highland at 300 highland. The weight, stem length, root length and leaflet size of the wild-simulated ginseng were higher than those of 600 highland at 300 highland.