연강의 전기화학적인 응력부식에 관한 연구(Ⅰ)

김석호 한국수산학회 1974 한국수산과학회지 Vol.7 No.4

5% H₂SO₄ 水溶液에 軟鋼材를 浸漬하여 두고 電壓 100㎷, 電流 100㎃ 下에 應力을 負加시킨 狀態로 電氣化學的인 腐蝕을 시켜 腐蝕으로 因한 質量損失 및 引張應力을 測定해 본 結果 다음과 같은 結果를 얻었다. 1. 腐蝕된 質量損은 腐蝕時 負加應力이 높을 수록 크지며, 처음부터 천천히 腐飾質量이 漸漸 增加하여 어느 一定한 時間(本 實驗에는 約 12時間)이 經過한 後에 서로 比例 關原가 成立함을 볼 수 있었다. 2. 負加應力과 腐餘으로 應力減少率은 서로 逆比例 關係가 成立하며, 降伏應力의 減少率과 引張應力의 減少率은 거의 一致하였다. 3. 材料의 不純物이 密集한 部分이나 結晶粒界가 먼저 腐蝕되어 漸次 擴大되었다. 4. 外力에 依한 內力(應力)이 潛하거나 加工硬化로 因한 空間格子의 變化가 있는 不安全한 組織을 가진 材料는 腐餘의 應力滅少率이 적었다. Electro-chemical aspects of stress corrosion on the mild steels when immersed in the 5% H₂SO₄ solution and charged with 100㎷ and 100㎃ were discussed. The main results of the experiment are follows; 1. The weight loss by corrosion was concerned with the applied stress. and the larger the applied stress, the greater the weight loss. 2. Reduction of corrosion stress was a factor of inverse proportion to the applied stress. 3. Corrosion began at first on the parts of impurities concentrated and the grain boundaries, and gradually developed and spreaded out. 4. The materials of unsteady structure deformed of space lattice by the high stress or workhardening showed less reduction of corrosion stress.

한국형 전투기 개발을 위한 전투기 임무격렬도 모델 연구

김석호,황영하,신기수,Kim, Sug-Ho,Hwang, Young-Ha,Shin, Ki-Su 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.2

The aim of this paper is to propose fighter aircraft's mission severity model which can be used as one of key factors for designing a structure and determining design life of KF-X. The mission severity is a quantitative data of flight loads and expressed by Nz(Vertical Load Factor) exceedances or occurrences. The severities of the flight loads depended on the circumstances of the countries which operate fighter aircraft. In this paper we have studied on Nz occurrences/exceedances of ROKAF fighter aircraft to generate mission severity model for the KF-X. The analyses of flight data were accomplished by using the Matlab.

Controlling for Doping Levels of Conducting Polymer Nanomaterials through Irradiation of Ion Beams

김석호,김도형,최진호,이호진,박정운,박동혁 한국고분자학회 2018 한국고분자학회 학술대회 연구논문 초록집 Vol.43 No.1

한국전통옹기의 통기성에 관한연구

김석호 한국조형예술학회 2006 조형예술학연구 Vol.9 No.-

ICR 마우스를 이용한 오미자박 추출물의 소핵 시험

김석호,김선연,김영숙,임종민,구본화,곽경태,전병엽 대한한의학방제학회 2022 大韓韓醫學方劑學會誌 Vol.30 No.4

Objectives : In this study, erythrocyte micronucleus test of pomace Schisandra chinensis extracts was conducted in order to up-cycling to a high value-added industry using by-products discarded in the production process of Schisandra chinensis products and active ingredients such as dibenzocyclooctadiene lignans in Schisandra chinensis. Methods : The micronucleus test was performed according to the 'OECD Guidelines'. Including the negative control group(0 mg/kg) and the positive control group(CPA 70 mg/kg), pomace Schisandra chinensis extracts were orally administered to ICR mouse at doses of 500, 1,000, and 2,000 mg/kg. After sacrificing the experimental animals bone marrow cells were collected and micronucleated polychromatic erythrocyte were counted. And genetic toxicity was confirmed according to the frequency of micronucleus. Results : As a result of the micronucleus test, there were no changes in body weight, clinical signs, or death in any group. But, a significant increase was observed in the frequency of micronucleated polychromatic erythrocyte among polychromatic erythrocytes in the positive control group administered with CPA compared to the negative control group(p<0.05). Whereas, no significant increase was observed in the group administered with pomace Schisandra chinensis extracts compared to the negative control group. Conclusions : Pomace Schisandra chinensis extracts did not induce micronucleus in bone marrow cells of ICR mouse up to a concentration of 2,000 mg/kg, and it was judged that no genetic toxicity was observed.

2-7 5% 황산수용액에서의 연강의 전기화학적인 응력부식의 효과

김석호 한국수산학회 1974 한국수산과학회지 Vol.7 No.4

船舶, 水中機器, 流送管 등에 使用되는 鋼材가 液體와의 接觸을 이루는 部分은 腐蝕이 쉽게 일어남은 日常經驗을 通하여 알려진 事實이다. 한동안 이것은 酸化 및 硫化의 被膜腐蝕으로만 解析되어 왔으나 근래에는 水素의 脆化腐蝕 및 電氣化學的인 腐蝕 등 여러 學說이 提唱되고 있으며, 그 중에서도 電氣化學說이 가장 有力한 解析이므로 各 學界에서 많은 硏究가 活潑히 進行되고 있다. 著者는 軟鋼이 電解液內에서 電氣化學的인 腐蝕을 할때 各己 다른 外力을 腐蝕材에 負加했을 경우에 일어나는 腐蝕의 程度(賃量損失)과 腐蝕應力의 滅小率을 調査하였으며 이 腐蝕程度가 林料內部의 粒子를 構成한 原子力의 畿換, 담금질 및 加工硬化 等에 미치는 영향과 연결시켜 解析하였다.

전기도금법으로 제조한 나노결정립을 갖는 Fe-Ni 합금의 열팽창 거동

김석호,손헌준,김영운,강탁,임태홍,이홍렬 한국표면공학회 2004 한국표면공학회 학술발표회 초록집 Vol.2004 No.-

Salmonella Serovars from Foodborne and Waterborne Diseases in Korea, 1998-2007: Total Isolates Decreasing Versus Rare Serovars Emerging

김석호 대한의학회 2010 Journal of Korean medical science Vol.25 No.12

Salmonella enterica has been one of the most widespread foodborne pathogens in Korea. Between 1998 and 2007, a total of 9,472 Salmonella isolates were identified from foodborne and waterborne illness patients. During that time, Korea was transitioning into a developed country in industry as well as in its hygiene system. Although the isolation number of total Salmonella including serovar Typhi has decreased since 1999, the isolation of rare Salmonella serovars has emerged. Three most prevalent serovars during 1998-2007were S. enterica Typhi, S. enterica Enteritidis, and S. enterica Typhimurium. There were remarkable outbreaks caused by rare serovars such as S. enterica Othmarschen, S. enterica London and S. enterica Paratyphi A, and overseas traveler-associated infections caused by S. enterica Weltevreden and S. enterica Anatum. Salmonella serovars from overseas travelers made a diverse Salmonella serovar pool in Korea. This study is the first review of the status of the human Salmonella infection trend in a developing country during 1998-2007. Newly emerging rare Salmonella serovars should be traced and investigated to control new type pathogens in the developed world.

Lack of Dream-Capital among Korean Youths: Rationally Chosen or Culturally Forbidden?

김석호,김홍중,이상규,김은지,권오재 서울대학교 사회발전연구소 2018 Journal of Asian Sociology Vol.47 No.3

This paper attempts to provide empirical evidence in understanding the ways that contemporary youth pursue their dreams in Korea. This paper examines the rational aspect of "dreaming" or "non-dreaming” by employing two concepts: dream-capital and penetration. In this paper, dream-capital is conceptualized as a seed that facilitates the accumulation of other capitals. It is the total capacity to dream and is composed of four dimensions: imagination, hope, optimism and resilience. Penetration is defined as the “cognitive judgment about the (un)realizability of dream.” It refers to the discrepancy that exists between judgment about the capacity, condition and qualification required to fulfill one’s dream and judgment about the extent to which one thinks she is equipped with that capacity, condition and qualification. Penetration consists of four factors: individual traits, ascribed status, individual qualifications, and national/social conditions. By analyzing the “Korean Youth Values Survey” data, this paper first examines how the general level of dream-capital is influenced by the total penetration score. And then, it also investigates the effects of four types of penetration on four dimensions of dream-capital. The results confirm that dream-capital is strongly affected by penetration. The ability to penetrate insufficient resources in pursuing dreams leads to lowering of dream-capital. Second, penetration on ascribed status and societal factors are found to be important predictors of dream-capital. These results reveal that for youth, the judgment made on their ascribed status rather than judgements made on individual trait or qualification plays a more important role in promoting dream-capital. The results imply that dreams are pursued and formed in close relation to rational cognitions among Korean youth. Korean youth are more likely to have dreams for long-term future when they believe that those dreams can be realized. Dreams are then rationalized fantasies.

Characterization of a Salmonella Enteritidis bacteriophage showing broad lytic activity against Gram-negative enteric bacteria

김석호,김성훈,Marzia Rahman,김정민 한국미생물학회 2018 The journal of microbiology Vol.56 No.12

In this study, we sought to isolate Salmonella Enteritidis-specific lytic bacteriophages (phages), and we found a lytic phage that could lyse not only S. Enteritidis but also other Gramnegative foodborne pathogens. This lytic phage, SS3e, could lyse almost all tested Salmonella enterica serovars as well as other enteric pathogenic bacteria including Escherichia coli, Shigella sonnei, Enterobacter cloacae, and Serratia marcescens. This SS3e phage has an icosahedral head and a long tail, indicating belong to the Siphoviridae. The genome was 40,793 base pairs, containing 58 theoretically determined open reading frames (ORFs). Among the 58 ORFs, ORF49, and ORF25 showed high sequence similarity with tail spike protein and lysozyme-like protein of Salmonella phage SE2, respectively, which are critical proteins recognizing and lysing host bacteria. Unlike SE2 phage whose host restricted to Salmonella enterica serovars Enteritidis and Gallinarum, SS3e showed broader host specificity against Gram-negative enteric bacteria; thus, it could be a promising candidate for the phage utilization against various Gram-negative bacterial infection including foodborne pathogens.