1Cr-0.5Mo 강 용접부 균열의 고온파괴거동 연구

이해무,윤기봉,신규인,최현창,박재학 한국산업안전학회 1997 한국안전학회지 Vol.12 No.2

Fracture behavior of ex-serviced 1Cr-0.5Mo steel was measured at room(24℃) and elevated(538℃) temperature and compared with that measured with virgin 1Cr-0.5Mo steel. Compact C(T) specimens were machined from the base and welded test materials. In case of the C(T) specimens of the weld, fatigue precrack was introduced along the fusion line so that following crack growth should occurs along the region of heat affected zone. It was observed that the J-R curve of the serviced material was significantly lower than that of the virgin material at room temperature. Brittle fracture was observed in the serviced material. On the other hand, at elevated temperature no noticeable difference was found between the J-R curves of the virgin and the serviced material. The measured J-R curves were also compared with those of the 1.25Cr-0.5Mo steel obtained from the other literatures. Optical microscopy and SEM examination of the serviced material reveal the carbide in/along the grain boundary which shows material degradation due to long-term usage. An example of application of the measured J-R curves is shown.

고로내와 류이한 조건하에서 알칼리 금속이 산화철의 환원반응과 코우크스의 가스화 반응에 미치는 영향

윤종규,조남교 대한금속재료학회(대한금속학회) 1983 대한금속·재료학회지 Vol.21 No.10

Among the mechanism and kinetics of iron oxide reduction and coke gasification reaction reported, only the reactions under isothermal condition or iso-gas compositions are reported. Very few papers are published concerning non-isothermal reactions. In this papers, experiments for the reduction of wustite along with the coke gasification were performed under the simulated conditions of thermal reserve zone of iron blast furnace which is apparently non - isothermal and non iso-gas composition. The main object of this research is to probe the rate and effect of alkaline metal additions on the wustite reduction and coke gasification. Temperature and gas compositions are varied to simulate the running conditions of old type and modern type blast furnace. Gas utilization factor is introduced to explain the abundancy or the shortage of the reducing gases in the blast furnace running conditions.

한국산 하루살이목(目)의 카탈로그

윤일병,배연재,전동준 고려대학교 한국곤충연구소 1994 昆蟲硏究誌 Vol.20 No.1

韓國産 하루살이目의 카탈로그. 裵淵宰 · 尹一炳^1 · 田東埈^2 (서울女子大學校, ^1高麗大學校 生物學科, ^2러시아科學院 動物學硏究所) 昆蟲硏究誌, 20: 31~50, 1994. 韓國産 하루살이目의 關한 硏究는 南北韓에 걸친 綜合的인 硏究가 이루어지지 못하였고, 1940년 以來 各種 文獻에 記錄된 種들에 있어서도 分類上 혹은 命名上 變動이 많았으나 이를 體系的으로 收錄하지 못하였다. 이 論文에서는 種合的인 文獻 및 模式標本 調査를 통하여 다음과 같이 韓國産으로 記錄된 56種의 命名상 有效한 種들에 대한 카탈로그를 작성하였다. Acerella longicaudata(U′eno), *Ameletus costalis (Matsumura), A. montanus Imanishi, *Baetiella japonica (Imanishi), *B, tuberculata (Kazlauskas), *Baetis thermicus U′eno, Bleptus fasciatus Eation, Choroterpes altioculus Kluge, Cincticostella castanea (Allen), C. tshernovae(Bajkova), * Cinygmula grandifaliz Tshernova, *C. hirasana (Imanisht), Cloeon dipterum (Linnaeus), Drunella aculea (Allen), *D. cryptomeria (Imanishi), *D. lepnevae (Tshernova), D. triacantha (Tsher-nova), *D. trispina ezoensis (Gose), Ecdyonurus bajrovae Kluge, E. dracon Kluge, **E. Joernensis mon-golicus Bajkova & Varychanova, E. kibunensis Imanishi, E. levis (Nava′s), E. scalaris Kluge, **E. subspinosa (Braasch & Solda′n), Epeorus curvatulus Matsumura, *E. hiemalis Imanishi, E. latifolium Ue′no, E. pellucidus (Broadsky), *Ephemeralla aurivillii Bengtsson, *E. imanishii Gose, E. keijoensis Allen, *E. notofascia Yoon & Base, Ephemera orientalis McLachlan, E. separigata Bae, E. strigata Eaton, Ephoron shigae (Takahashi), Heptagenia guranica Belov, H. kihada Matsumura, *H. Kyotoensis Gose, *Iron aesculus (Imanishi), *I. koreanicus Braasch & Solda′n, I. maculatus Tshernova, Isonychia japonica (Ulmer), **I. ussurica Bajkova, Paraleptophlebia chocolata Imanishi, *Potamanthellus rarus tiunova & Levanidova, **Potamanthus formosus Eaton, P. yooni Bae & McCafferty, *P. luteus oriens Bae & McCafferty, *Phithrogena japonica Ue′no, Rhoenanthus coreanus (Yoon & Bae), *Serratella setigera (Bajkova), Siphlonurus chankae Tshernova, *S, sanukensis Takahashi 및 Uracanthella rufa (Imanishi). 별표한 種들은 幼蟲만이, 쌍별표한 種들은 成蟲만이 韓國産으로 記載되었다. (C. tshernovae와 E. keijoensis는 암컷 成蟲과 幼蟲만이, 그리고 P. luteus oriens는 亞成蟲만이 韓國産으로 記載되었다.) 다음 10종은 韓國에서 幼蟲만이 記載되었고, 아직 命名上으로 留保된 未決定種으로 남아있다. Baetis Kua: Yoon & Bae, Baetis nla: Imanishi, Brachycercus Kua: Yoon & Bae, Caenis Kua: Yoon & Bae, Cinygmula Kua: Yoon & Bae, Cinygmula na: Imanishi, Ecdyonurus Kub: Yoon & Bae, Ecdyonurus na: Imanishi, Paraleptophlebia nb: Imanishi 및 Rhithrogena na: Imanishi. 각 種에 있어서 原記載 및 再記載 文獻, 記載에 使用된 標本, 分布, 模式標本에 대한 情報, 異名과 命名上의 變動을 年代順으로 整理하였다. 附錄으로 南韓種만의 checklist와 分類學的 變動 및 國名의 變動事項을 表로 作成하였다. Mayflies (Ephemeroptera) of Korea have been described in various literatures since 1940, but there have been many taxonomic or nomenciatural changes in the members of the order. A comprehensive literature and type material review of the Ephemeroptera resulted herein the recognition of 56 nomenclaturally valid species previously described from Korea : Acerella longicaudata (Ue´no), ^*A meletus costalis (Matsumura), A. montanus Imanishi, ^*Baetis thermicus Ue´no, Bleptus fasciatus Eaton, Choroterpes altioculus Kluge, Cincticostella castanea (Allen), C. tshernovae (Bajkova), ^*Cinygmula grandifolia Tshernova, ^*C. hirasana (Imanishi), Cloeon dipterum (Linnaeus), Dyunella aculea (Allen), ^*D. cryptomeria (Imanishi), ^*D. tepnevae (Tshernova), D. triacantha (Tshernova), ^*D. trispina ezoensis (Gose), Ecdynurus bajrovae Kluge, E. dracon Kluge, ^*^*E. joernensis mongolicus Bajkova & Varychanova, E. kibunensis Imanishi, E. levis (Nava´s), E. scalaris Kluge, ^*^*E. subspinosa (Braasch & Solda´n), Epeorus curvatulus Matsumura, ^*E. hiemalis Imanishi, E. latifolium Ue´no, E. notofascia Yoon & Bae, Ephemera orientalis McLachlan, E. separigata Bae, E. strigata Eaton, Ephoron shigae (Takahashi), Heptagenia guranica Belov, H. kihada Matsurnura, ^*H. kyotoensis Gose, ^*Iron aesculus (Imanishi), ^*I. Koreanicus Braaich & Solda´n, I. Maculates Tshernova, Isonychia japonica (Ulmer), ^*^*I. Ussurica Bajkova, Paraleptophlebia chocolate Imanishi, ^*Potamanthellus rarus Tiunova & Levanidova, ^*^*Potamanthus formosus Eaton, P. yooni Bae & McCafferty, ^*^*P. luteus oriens Bae & MeCafferty, ^*Rhithrogena japonica Ue´no, Rhoenanthus coreanus (Yoon & Bae), ^*Serratella setigera (Bajkova), Siphlonurus chankae Tshernova, ^*S. sanukensis Takahashi, and Uracanthella rufa (Imanishi), The asterisked species were known to larva only from Korea, and the double asterisked were adults only (C. tshernovae and E. keijoensis were females and larvae only, and P. luteus oriens was subimagos only), The following 10 species were known to larvae only from Korea, but have not been determined: Baetis Kua: Yoon & Bae, Cinygmula Kua: Yoon & Bae, Baetis nla: Imanishi, Brachycercus Kua: Yoon & Bae, Caenis Kua: Yoon & Bae, Cinygmula Kua: Yoon & Bae, Cinygmula na: Imanishi, Ecdyonurus Kub: Yoon & Bae, Ecdyonurus na: Imanishi, Paraleptophlebia nb: Imanishi, and Rhithrogena na: Imanishi. For each species, original and secondary sources of the descriptions, materials used, type information, distributions, synonyms, aid nomenclatural changes were chronologically provided. A checklist of the Ephemeroptera previously recorded from South Korea was appended with their proposed Korean name.

당뇨병의 병형에 따른 합병증에 관한 연구(예보)

이현철,허갑범,이이형,윤정환,임승길,윤금석,김원중,김현만 대한당뇨병학회 1985 Diabetes and Metabolism Journal Vol.9 No.2

변형된 트랜스듀서 및 FM을 이용한 이식형 인공중이 시스템의 전력효율 개선

윤영호,원철호,송병섭,정영숙,김명남,박세광,이상흔,조진호 경북대학교 전자기술연구소 1997 電子技術硏究誌 Vol.18 No.2

In design of implantable middle ear system, it is necessary that the system has a high power-transfer efficiency because die internal circuit of the system has no power source. The FM transmission method transfers the signal power more efficiently than AM method because AM signal has large carrier component which act as the loss. Therefore, an implantable middle ear system using FM transmission and receiving method is proposed. And the new shape of vibrating transducer which vibrate more efficiently than the conventional type was designed. This tranducer is consisted of coil and small T-type cylindrical permanent magnet. The differences between conventional methods and proposed methods are investigated and compared through quantitive analysis. The advantages of proposed methods are proved by experiments.

LPG 탱크로리 수송중 위험성 평가에 관한 연구

이재준,김윤화,엄성인,고재욱,백종배,윤성렬 한국산업안전학회 1997 한국안전학회지 Vol.12 No.4

Demand of LPG and LNG will increase continuously due to high calories, clearness, and convenience for usage. These gases are used widely for power plants, industrial plants, and domestic fuel. But accidents related with gas are increasing in proportion to increment of gas usage. Especially, LPG has high ignitability due to weak dispersion to air and accumulation at low place because LPG is heavier than air. There are many hazards during transportation as well as production, storage, and usage of LPG. Commonly, tank lorry is used for inland transportation of LPG. If tank lorry were to raise leakage incidents and then LPG released during transporting, the accidents cause serious effects on the environment as well as human damage of surrounding area. In this study, therefore, hazards which cause LPG of tank lorry to leak during transportation were identified and risk of LPG transportation was assessed quantitatively. Also, the result of this study might be a useful measure for predicting damage and preparing safe transportation strategies of LPG tank lorry.

암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용한 최대산소섭취량 추정에 관한 연구

정성태,전태원,정덕조,정영수,엄우섭,이동기,윤호섭 한국운동과학회 2000 운동과학 Vol.9 No.1

암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용한 최대산소섭취량 측정에 관한 연구 운동과학. 제 9권 제 1호. (1)-(12), 2000. 본 연구의 목적은 암에르고미터 운동시 여유심박수에서의 신체작업능력(PWC%HRR)을 이용해 최대산소섭취량(O₂_(max))을 추정하는데 있어 그 타당성을 보는데 있다. 이를 위해 본 연구에서는 건강한20대 남자 대학생(21.1±2.77)20명이 참가 하였다. 이들의 안정시 심박수는 5분간 EKG로 측정되었고, 최대산소취량은 암에르고미터에서 50rpm의 속도로 20W에서 운동을 실시하고 매 3분 간격으로 10W씩 증가시켜 피험자가 탈진시까지 운동을 지속시켰다. 여유심박수 계산에 있어서 최대심박수는 수식(HRmax = 210 - age)으로 계산되었다. PWC%HRR의 계산은 점증부하 운동상에서 120≤R≥160의 범위에 발견된 HR과 O₂의 관계식(Y=bx+a)에 의하였다. 강도별 상대적 백분율 범위는 50∼85%사이였으며, 비교대상은 PWC%HRR, O₂R, O₂_(max)이었다. 그 결과 다음과 같은 결과를 얻었다 첫째, %HRR과 O₂R, O₂_(max)간의 회귀분석결과 %HRR은 O₂_(max)보다 O₂R에 가까웠다. 둘째, 각 강도별 PWC%HRR과 O₂R, O₂_(max)간에는 통계적으로 유의한 차이는 없었으나, PWC%HRR은 O₂_(max)보다 O₂R에 보다 가까웠다(P<.05). 셋째, O₂_(max)의 실측치와 PWC%HRR = O₂R에 의한 추정치 사이에는 모든 강도에서 통계적으로 유의한 차이가 없었으나, 상관관계는 PWC%HRR에서 가장 높았다(P<.05). 이상의 결과를 종합해 볼 때 암에르고미터 운동검사 과정에서 만족할 만한 O₂_(max) 발견하지 못했더라도 최소한 60%HRR에 해당하는 심박수가 발견될 때까지 운동을 수행하였다면 일련의 방식에 의해 O₂_(max)의 추정이 가능하다고 본다. The study on Estimation of maximal oxygun uptake through PWC%HRR during Arm Ergometer Exercise. Exercise Science, 9(1): 1-12, 2000. The purpose of this study was to evaluate the validity for estimation of maximal oxygen uptake through PWC%HRR during Arm Ergometer Exercise. The subjects of this study were 20 healthy males(21.2±2.77yrs) college students. Resting heart rate of subjects were recorded by EKG for 5min. the maximal oxygen uptake was determined until subjects were exhausted. The first stage was performed 50rpm, 20W, and then was increased by 10W every 3 minutes on the arm ergometer. HRmax was determined by a numerical formula of HRmax = 210-age. PWC%HRR was assessed by relative equation (Y=bX+a) of HR and V˙O₂ observed in range 120≤R≥160 during the exercise test. Range of relative percentage was between 50% and 85%, comparison factor was examined among PWC%HRR, % V˙O₂R and % V˙O₂_(max). The results of this study are as follows : 1) Result of the regression analysis among PWC%HRR, % V˙O₂R and % V˙O₂_(max), %HRR was equivalent to % V˙O₂R rather than V˙O₂_(max). 2) No significant difference was observed among PWC%HRR, % V˙O₂R and V˙O₂_(max) in the all intensity, But the PWC%HRR was closer to % V˙O₂R rather than V˙O₂_(max)(P<.05). 3) No significant difference was the actual V˙O₂_(max) and the estimation value by PWC%HRR = % V˙O₂R in the all intensity, and the correlation analysis was the most correlated at the estimation value by PWC%60HRR. It was concluded that if the satisfactory V˙O₂_(max) was not found in Arm Ergometer exercise test but heart rate corresponded to 60%HRR, V˙O₂_(max) can be estimated by a series of equation.

SUS 300 계 스테인리스강의 표면특성에 관한 연구

이경구,윤동주,기회봉,최답천,이도재 한국열처리공학회 1999 熱處理工學會誌 Vol.12 No.1

In the present study, oxidation behavior of 304 and 316 stainless steels Was investigated. After solution treatment, specimens were polished up to 1㎛ Al₂O₃grade and then subjected to oxidation treatment in dry air. The range of temperature was used for oxidation treatment at 300℃∼500℃ and TEM was used for analyzing the components and structure of oxide film. Also, these results were compared with the results of ESCA and TG. According to the results of TEM analysis, it was found that Cr oxide film was formed on top of the surface after room temperature oxidation but amorphous Fe oxide was formed on top of the surface and polycrystalline (Cr,Fe)₂O₃was formed below the amorphous Fe oxide layer after 500℃ oxidation treatment. The oxidized specimens at 500℃ showed that 316 stainless steel resists more strongly to grain and grain boundary oxidation than 304 stainless steel. These results suggested that Mo component resolved in 316 stainless steel matrix suppressed the formation of Cr carbide which may results in local Cr deplete area.

13%Cr 스테인리스강의 표면 질소침투처리에 미치는 Al 첨가의 영향

강창룡,성장현,이해우,김기돈,윤삼석 한국열처리공학회 1999 熱處理工學會誌 Vol.12 No.3

The surface nitrogen permeation of Al alloyed 0.14%C-13%Cr stainless steels was investigated after heat treating at 1050℃∼1150℃ in the nitrogen gas atmosphere. The strong affinity between Al and nitrogen permeates the nitrogen through the interior of the steels. Two precipitates of round type and needle type are observed at the surface layer. These precipitates mainly consist of AlN containing plenty of aluminum. The surface layer of 0.53%Al alloyed specimen shows ferrite phase, while the surface layers of 1.65%Al and 2.27%Al alloyed specimens appear γ plus α phases. The depth of nitrogen permeation depends upon the Al content and microstructure of the matrix. The 1.65%Al alloyed specimen representing α+γ matrix phases at the nitrogen permeation temperature shows the maximum case depth in this experiment. Although the surface hardness increases by raising the Al content of the specimen owing to the increase of nitride precipitation density, the nitride precipitation deteriorates the corrosion resistance in the solution of HCl, H₂SO₄, and FeCl₃.

후드의 충만효과(充滿效果) 활용기법(活用技法)에 관한 연구

이상호,윤명조,김정현,강준원 한국산업위생학회 1991 한국산업보건학회지 Vol.1 No.1

In order to visualize the distribution of workplace of which mixed solvent level in air exceeded the TLV of 1.0 (ACGIH), 17 thinners used in 44 painting workplaces were analysed with gas chromatography, and their levels in air were compaired with. 1. For detection rate of solvents in thinner was highest in case of toluene(76.4%), and decreased in orders of xylene (70.6%), methylisobutyl ketone (35.3%), acetone (35.3%), methylethylketone (23.5%), isopropylacohol (17.6%), n-hexane (17.6%), styrene (11.8%), and ethylacetate (1.8%). Average number of solvents detected was 3.0. 2. Detection rates of organic solvent by component category was highest in cases of aromatic hydrocarbons (52.9%), and decreased in orders of ketones (31.4%), alcohols (5.9%), n-hexane (5.9%) and esters (3.9%). The rate by regulatory category, the second category component was detected in 93.9% of total. 3. There was significant correlation (r=0.929, p<0.01)between detection rates of solvents in thinner and in air. 4. Among the total of 44 painting workplace, the rate of them of which level of mixed solvents in air was exceeded was highest in case of aromatic hydrocarbons (29.5%), and decreased in orders of ketones (6.8%), alcohol (2.3%), n-hexane (2.3%), and was highest in guitar painting (71.4%) workplace in case of aromatic hydrocarbons by component category.