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.

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

Skull법에 의한 Cubic Zirconia 단결정 성장

김석호,최종건,오근호,조영환,김영준,오봉인,강원호 한국세라믹학회 1988 한국세라믹학회지 Vol.25 No.2

Yttria-Stabilized Cubic Zirconia Crystals with Various Y2O3 amounts (6-15mol%) were grown by the Skull melting technique. The modeling of the nucleation at the Skull bottom and the best growth condition were studied. The abrupt changes in generator heating Power and lowering rate of crucible caused the dendritic growth in the grown crystal. The optimum condition of cubic Zirconia single crystals was obtained when the lowering rate was gradually increased. The effect of Y2O3 amounts on the perfection adn the color of the grown crystal were determined. The darkish color generated in the crystals added Y2O3 amounts over 12mol% was eliminated by the annealing in air at 1200$^{\circ}C$ for 24hrs.

SD-rats를 이용한 오미자박 추출물의 급성경구독성 평가

김석호,유보라,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, acute oral toxicity 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 : Pomace Schisandra chinensis extracts were orally administered to SD-rats(female, n=3) without a control group according to the 'OECD guidelines'. After, mortality and clinical signs were observed, and the deceased animals were subjected to an autopsy. In addition, acute oral toxicity test was sequentially performed in step Ⅰ(300 mg/kg), step Ⅱ(300 mg/kg), step Ⅲ(2,000 mg/kg), and step Ⅳ(2,000 mg/kg) according to the mortality. Results : There were no abnormalities caused by pomace Schisandra chinensis extracts in step Ⅰ and step Ⅱ. However, one animal each died in step Ⅲ and step Ⅳ. In addition, clinical signs(salivation, decrease in food intake, prone position, decrease of locomotor activity, loss of locomotor activity, convulsion, hypothermia, lacrimation, staining around mouth, soiled perineal region, reddish urine, chromaturia, decrease of fecal volume, lying on side, blackish stool, no stool, compound-colored stool, refusal to feed, excitement, hypersensitivity, rigidity, dorsal position, etc.) were observed. But, no clinical signs were observed from 5th day, and experiment animals recovered completely. Conclusions : As a result of this study, pomace Schisandra chinensis extracts may exhibit acute toxicity at concentrations of 2,000 to 5,000 mg/kg, and the GHS classification was designated as 'Category 5'.

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.

The applications of nitrogen-doped graphene

김석호,양문호,장동욱 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.1

Growth and Application of Organic Small Molecule Crystals for UV Photodetector

김석호,박동혁,이선종 한국고분자학회 2019 한국고분자학회 학술대회 연구논문 초록집 Vol.44 No.1

사회적 자본이 사회적 기업에 미치는 영향 : 주관적 안녕의 매개 효과를 중심으로

김석호,이석형 국제차세대융합기술학회 2020 차세대융합기술학회논문지 Vol.4 No.3

본 연구는 사회적 기업이 성장하고 발전하면서 영향을 미치는 다양한 변수에 대응하는 연구가 비교적 적 은 시점에서 사회적 자본과 사회적 기업에 대하여 심층적으로 알아보고 더 나아가 시민의 주관적 안녕을 조절변 수로 사회적 기업에 미치는 영향을 확인하고자 하였다. 분석결과 사회적 자본의 세가지 차원 네트워크, 신뢰, 규범 이 주관적 안녕에 유의한 영향을 보였고 나아가 주관적 안녕은 사회적 기업에 대한 태도에 유의한 영향을 미치는 것으로 나타났다. 이러한 결과는 사회적 자본을 통해 주민의 행복감이 증가되고 이러한 행복감이 사회적 기업에 긍정적인 작용을 하기 때문에 사회적 기업은 시민들과 상생할 수 있는 다양한 기회 및 정보를 제공하는 체계를 구축할 필요성을 제시하고 시민의 삶의 질을 높임으로써 사회적 기업과 같이 성장할 수 있는 시사점을 제공할 것 으로 사료된다. The present The purpose of this study was to identify the impact of the subjective well-being of citizens on social enterprises as a control variable in the relatively small number of studies on the various variables that affect the development and growth of social enterprises. The analysis showed that the three dimensions of social capital networks, trust, and norms showed a significant positive influence on subjective well-being, and furthermore subjective well-being had a significant positive influence on attitudes toward social enterprises. As social capital increases the euphoria of residents and this euphoria positively affects social enterprises, social enterprises are expected to provide implications for the need to establish a system that can provide various opportunities and information for both businesses and citizens to develop, and to provide a basis for co-prosperity with social enterprises by improving the quality of life of citizens.

상호신뢰는 병원발전의 초석

김석호,Kim, Seok-Ho 대한병원협회 2003 대한병원협회지 Vol.32 No.6