• 한국자원식물학회지
• /
• 제32권4호
• /
• pp.379-406
• /
• 2019

주왕산국립공원의 관속식물상을 2017년도 3월부터 10월까지 총 13회에 걸쳐 조사하였다. 증거표본과 사진을 바탕으로 작성한 소산 관속식물은 112과 399속 672종 4아종 72변종 10품종의 총 758분류군으로 확인되었다. 이 중 기존의 조사에서는 발견되지 않았으나 본 조사에서 최초로 밝혀진 분류군은 221분류군이었다. 멸종위기야생식물은 가시오갈피, 큰바늘꽃 등 2분류군이 확인되었고, 희귀식물은 깽깽이풀, 백작약, 꼭지연잎꿩의다리 등 5분류군이 관찰되었다. 한반도 고유식물은 날개현호색, 노랑무늬붓꽃, 몽울토현삼 등 20분류군이 조사되었고, 식물구계학적 특정식물종은 III~V등급에 해당하는 40분류군이 확인되었다. 귀화식물은 총 55분류군으로 조사되었고, 생태계교란종은 가시상추, 돼지풀, 미국쑥부쟁이 등 3분류군이 확인되었다. 기후변화 취약종은 총 36분류군이 분포하였고, 북방계 21분류군, 남방계 2분류군, 관심식물은 13분류군으로 확인되었다.

• Geomechanics and Engineering
• /
• 제6권5호
• /
• pp.437-453
• /
• 2014

This paper studies the swelling and strength characteristics of unimproved and improved expansive soils in terms of the swell potential, swelling pressure, rate of secondary swelling, unconfined compressive strength and California bearing ratio (CBR). The admixtures used in this study are locally available cement and fly ash. The soils used in this study were taken from the Mae Moh power plant, Lampang Province, in northern Thailand. A conventional consolidation test apparatus was used to determine the swelling of the soil specimen. The optimum admixture contents are determined to efficiently reduce the swelling of unimproved soil. The rate of secondary swelling for unimproved soil is within the range of highly plastic montmorillonite clay, whereas the specimens improved with optimum admixture contents can be classified as non-swelling kaolinite. A soil type affects the swelling pressure. Expansive soil improvement with fly ash alone can reduce swelling percentage but cannot enhance the unconfined compressive strength and CBR. The strength and swelling characteristics can be predicted well by the swelling percentage in this study.

• 대한기계학회논문집A
• /
• 제21권1호
• /
• pp.173-179
• /
• 1997

The high temperature fatigue tests were performed using the specimens taken from Cr-Mo-V steel, widely used as thermal power plant turbine materials for examination fatigue behavior of materials in power plants which have been operated for long periods. The fatigue tests at high temperature were performed at the various temperature and applied stress. The results obtained are summarized as follows : The fatigue crack length increases and the fatigue life decreases with temperature and applied stress according to the same number of stress cycle. The fatigue crack propagation and the fatigue life were much influenced by temperature and applied stress.

• 한국응용곤충학회지
• /
• 제43권2호
• /
• pp.91-101
• /
• 2004

본 연구는 한국과 인접해 있는 중국동북지역에 분포하는 무늬잎말이나방족의 분류학적 연구결과로, 현재까지 보고된 종들과 새롭게 추가되는 중국미기록 2종(Aclerishastina(Linnaeus), A. lacordairana (Duponchel)) 및 중국동북지 역 미기록 1종(Croesia crataegi (Kuznetsov))을 포함하여 총 4속 36종으로 정리되었다. 정리된 종별 정보는 동물이명, 기록문헌, 기주식물, 분포정보 등 필수정보들도 종합 작성되었다.

• 한국압력기기공학회 논문집
• /
• 제7권2호
• /
• pp.21-25
• /
• 2011

Although many defects in PZR heater sleeve have been reported continually from operating experiences in oversea nuclear power plant, utilities get into difficulties in finding appropriate methods for diagnostics of the components due to the limited access or high radiation problems. Recently, as an alternative, diagnostics using Guided Wave Testing(GWT) are proposed and the attention of the methods has been growing gradually because of their long range inspection capability. This study is to investigate the effectiveness of GWT to detect PWSCC in welding points of PZR heater sleeve. Moreover, mode sensitivity analysis of GWT and optimal frequency for the diagnostics of PWSCC are presented by testing the mock-ups specimens that contain artificial flaws.

• 한국유체기계학회 논문집
• /
• 제1권1호
• /
• pp.17-23
• /
• 1998

The blade failures are identified as the leading cause of unplanned outages for steam turbine. Most investigations of the failures are limited to material tests, chemical analysis of deposits, and possibly examination of material specimens. But to correct a blading problem requires more than positive identification of the mechanisms involved. An analytic procedure capable of predicting stress and dynamic characteristics of turbine blades is presented to increase steam turbine availability by decreasing blade failures. Finite element method is used to model and predict natural frequencies, steady and dynamic stresses of turbine blades. The procedure is illustrated by the case study. This procedure is used to guide, and support the plant manager's decision to avoid a costly, unplanned outage

• 한국정밀공학회지
• /
• 제17권4호
• /
• pp.85-96
• /
• 2000

An Eggcrate assembly is an important part to hold and support 16,000 tubes containing hot and contaminated water in the steam generator of nuclear power plant. As a great number of tubes should be inserted into the eggcrate assembly, the dimensions of each eggcrate grid are one of the critical factors to determine the availability of tube insertion. in this paper. we propose a machine vision algorithm for measuring the inner-circle diameter of each eggcrate grid whose shape is not exact quadrangular. The overall procedure of the algorithm is composed of camera calibration, eggcrate image preprocessing, grid height adjustment, and inner-circle diameter estimation. The algorithm is tested on real specimens and the results show that the algorithm works fairly well.

• 한국응용곤충학회지
• /
• 제50권1호
• /
• pp.75-77
• /
• 2011

Andaspis속의 Andaspis crawii (Cockerell)와 Andaspis kashicola (Takahashi) 2종을 처음으로 국내분포로 보고하고, 한국산 Andaspis속의 종 동정에 필요한 검색표, 사진자료, 분포 및 기주 정보를 함께 기재하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1702-1707
• /
• 2007

The reduction of pipe-thickness induced by flow accelerated corrosion (FAC) is one of the most serious problems on the maintenance of piping system in nuclear power plants (NNP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain pressure and consequently results in leakage or rupture. For this reason, wall thinning by FAC has been inspected in secondary side piping systems in NPPs. In this research Round Robin Test (RRT) was conducted to verify confidence of wall thinning measurement system in NPP. 12 inspectors from 3 companies participated and 23 specimens were used according to standard practice in RRT. The gage R&R analysis was introduced in regard to repeatability and reproducibility that are affected to measurement system errors. Confidence intervals of thickness measurement system were obtained.

• 패션비즈니스
• /
• 제11권1호
• /
• pp.125-135
• /
• 2007

Each cotton fiber is a unicellular hair collected from the seed of cotton plant. The fiber contains many convolutions along its length. Mercer was the first to suggest caustic soda treatment of cotton in commercial application. Mercerization has been commercially used since Lowe's suggestion to endow cotton with increased strength and affinity for dyes with additional properties such as fabric touch or luster. In this study, cotton fabric specimens were mercerized to investigate the changes in physical and mechanical properties pertaining to the hand or touch of fabrics. Physical properties were measured using the KES(Kawabata Evaluation System).