Environmental Microbiology / Microbial Diversity : Calcium Carbonate Precipitation by Bacillus and Sporosarcina Strains Isolated from Concrete and Analysis of the Bacterial Community of Concrete(s)

( Hyun Jung Kim ),( Hyo Jung Eom ),( Chulwoo Park ),( Jaejoon Jung ),( Bora Shin ),( Wook Kim ),( Namhyun Chung ),( In Geol Choi ),( Woojun Park ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.3

Microbially induced calcium carbonate precipitation (CCP) is a long-standing but re-emerging environmental engineering process for production of self-healing concrete, bioremediation, and long-term storage of CO2. CCP-capable bacteria, two Bacillus strains (JH3 and JH7) and one Sporosarcina strain (HYO08), were isolated from two samples of concrete and characterized phylogenetically. Calcium carbonate crystals precipitated by the three strains were morphologically distinct according to field emission scanning electron microscopy. Energy dispersive X-ray spectrometry mapping confirmed biomineralization via extracellular calcium carbonate production. The three strains differed in their physiological characteristics: growth at alkali pH and high NaCl concentrations, and urease activity. Sporosarcina sp. HYO08 and Bacillus sp. JH7 were more alkali- and halotolerant, respectively. Analysis of the community from the same concrete samples using barcoded pyrosequencing revealed that the relative abundance of Bacillus and Sporosarcina species was low, which indicated low culturability of other dominant bacteria. This study suggests that calcium carbonate crystals with different properties can be produced by various CCP-capable strains, and other novel isolates await discovery.

Effects of Pilger Rolling and Heat Treatment on Microstructure and Corrosion Resistance of Ag-electroplated 304 Stainless Steel Tubes

Hyun Park,Woo‑Jin Lee,Jae‑Han Son,Han‑Kyun Shin,Sung‑Kyu Hong,Hyo‑Jong Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

We introduce a cost-effective method that combines electroplating with metal cold working processes to manufacture compositetubes with robust corrosion resistance. First, a 3-step electroplating process was developed to form an adhesive anduniform Ag coating on the outer wall of a 304 stainless steel tube. The process consisted of a Ni-strike step for removing thepassivation layer of the initial 304 tube, Cu deposition for smoothing the surface by adding a buffer layer, and Ag deposition. To reinforce the interfacial adhesion between the electroplated layers and the 304 tube and increase the area of the Ag coating,a pilger rolling or pilger rolling + heat-treatment process was performed after the Ag electroplating process. Scanningelectron microscopy of the composite tubes after each process indicated that the as-deposited Ag coating changed fromhaving a rough to smooth surface after only pilger rolling and with additional heat treatment. Electron backscatter diffractionanalysis of the microstructures and textures of the tubes revealed that dynamic recrystallization occurred extensively duringpilger rolling, resulting in the formation of a relatively defect-free grain structure without heat treatment. Furthermore,electrochemical polarization curves determined that the Ag-coated composite tubes are superior to the uncoated 304 tubein terms of corrosion resistance under Cl−atmosphere, owing to the formation of a AgCl passivation layer during testing. Surface analysis of the composite tubes suggests that the properties of the AgCl passivation layer are related to the grainsize of the Ag coating and the density of plastic-deformation-induced defects.

구개열 아동 언어의 진단 평가

신효근,고승오,홍기환,서정환,고도흥,김현기 大韓顎顔面成形再建外科學會 1998 Maxillofacial Plastic Reconstructive Surgery Vol.20 No.1

女性 能力 開發을 위한 女性學課程 設置의 提案

玄永學,鄭世華,李男德,李效再 이화여자대학교 한국문화연구원 1976 韓國文化硏究院 論叢 Vol.28 No.-

For the past 20 years, there has been a substantial increase in the percentage of women going to colleges and universities in Korea: the statistics indicate that the male and female ratio changed from 87.3% to 12.2% in 1952 to 73.9% to 26.1% in 1974. Inspite of the increasing trend, some academic observers recently began to voice their opinions against higher education for women on the basis that Korean women, regardless of their education in an occupation or public life. The following trends partially support this opinion. First, the tendency of female students concentrating their major fields on a limited number of specializations, such as teachers' education, language, arts, nursing and medical technology, is a contrasting phenomenon with male students, who are more or less evenly distributed throughout all the areas of specialization as their major fields. Second, the remarkable increase in female labor participation for the past 10-15 years is largely contributed by women in the agricultural sector and manufacturing industries, as the percentage of women with higher education have shown not as much of an increase in the labor market as that of these with elementary level or less education. Furthermore, the percentage of women in professions and managerial occupations which would require college education for qualification toward has decreased from 2% in 1960 to 1.8% in 1970. Thirdly, a survey of Ewha graduates concerning their attitudes toward women's social role and college education presents revealing results of their conservatism and resignation sex equality and occupational roles. These findings certainly contradict the egalitarian principles of modern higher education and human potentials. However, there are now growing trends among female college students, with the awareness of changing sex roles, of taking seriously their future occupations and other social roles in addition to marriage. They are showing a greater concern for developing their potentials for professions and egalitarian roles for society, realizing the need for overcoming socio-cultural limitations as well as personal inertia. These are signs calling for new directions in women's education in Korea by introducing women studies programs which are designed to liberate women from the culturally conditioned state of self-awareness and the traditional status and role.

해바라기 뿌리-조직 바이오센서에 의한 과산화수소의 정량에 관한 연구

박현영, 권효식 충북대학교 과학교육연구소 2011 과학교육연구논총 Vol.26 No.2

본문 참고

소음 측정을 통한 에어컨 실내기 자기음 검출 및 진단

지효근,정호제,김정현 경성대학교 공학기술연구소 2012 공학기술연구지 Vol.18 No.-

This paper presents the detection and diagnosis of air-conditioner electromagnetic sound through noise measurements. Electromagnetic sound originating from the motor is an unpleasant source of unwanted noise that should be detected at the manufacturing stage. A detection system using sound measurements was built and a detection algorithm based on FFT analysis is presented. Soun measurements are preferable over direct vibration measurement because it is non-contact and low cost. Experimental results show that our sound measurement system can detect electromagnetic sound effectively compared to using vibration measurements.

[논문]리빙 라디칼 중합의 응용: 단백질과 고분자의 결합을 통한 새로운 하이브리드 재료 개발

이효경,백현종 釜山大學校生産技術硏究所 2006 生産技術硏究所論文集 Vol.65 No.-

리빙라디칼 중합은 원하는 구조의 잘 규정된 고분자를 손쉽게 만들 수 있는 새로운 합성 방법이다. 리빙라디칼 중합은 다양한 재료의 합성에 응용되고 있으며 특히 바이오 분야에서 활발한 연구가 진행되고 있다. 본고에서는 단백질과 고분자의 결합을 통한 소재개발 연구를 중심으로 리벙 라디칼 중합의 바이오응용에 대하여 소개하고자 한다.

불확실성 모델링을 사용한 지하철 건설공사의 확률적 위험도분석

조효남,최현호 漢陽大學校 工學技術硏究所 2000 工學技術論文集 Vol.9 No.1

본 논문은 실제 건설공사에 적용할 수 있는 합리적이고도 체계적인 확률적 위험도분석 평가기법에 관한 연구로서 자료가 절대적으로 부족한 국내 현실에서 효과적으로 적용할 수 있는 위험도분석평가 모델을 제안하였다. 제안된 위험도분석평가 모델은 퍼지기법을 이용하여 전문가의 주관적인 판단을 위험도분석평가에 효과적으로 정량화 함으로써 분석 데이터가 부족한 국내 현실에서도 쉽게 적용 가능하게 하였으며, 언어적 불확실량의 모델링을 위해서 언어적이고 정성적인 표현을 정량적이고 확률적인 표현으로 전환하는 퍼지집합이론을 고려했다. 또한 적절한 분석기법 및 절차를 포함하고 있는 본 논문에서 제안한 절차를 바탕으로 전형적인 지하철 건설프로젝트의 위험도분석평가에 적용하여 건설공사 프로젝트를 위한 위험도 분석평가 모형의 적용성을 검증하였다.

홍국 풀을 이용한 김치 제조 및 품질 특성

김현정,박정현,황보미향,이효주,이인선 한국조리과학회 2003 한국식품조리과학회지 Vol.19 No.6

Kimchi was prepared with the addition of 2.5% and 5.0% Monascus purpureus koji(MPK) paste (20%) and were fermented at 20C for 18 days. The quality and sensory characteristics of the kimchi were evaluated by analyzing the pH, acidity, number of viable cells, the concentration of reducing sugar, and sensory properties during fermentation. The pH and titratable acidity of the kimchi prepared with MPK(MPK kimchi) were higher and lower, respectively, than those of the control kimchi. The MPK kimchi showed high 'L' and 'b' values during storage, but the 'a' values were low. The contents of the reducing sugar of the MPK kimchi tended to increase during fermentation, particularly after six days. The number of total microbial cells, lactic acid bacteria and yeast in the MPK kimchi were lower than those of the control kimchi until 3 days of fermentation. However, the number of these bacteria in the MPK kimchi and the control kimchi after six days of fermentation was similar. The sensory score of the kimchi with 2.5% and 5.0% added MPK paste were significantly higher than the control groups in terms of the sweetness and overall acceptability.

새로운 프로톤-펌프 저해제의 합성

김효정,박일현 충남대학교 1996 忠南科學硏究誌 Vol.23 No.1

For development new anti-ulcer agents, we synthesize omeprazole analogues, in which pyridine group replaced by pyrazole moiety, to increase pharmacological activity and to decrease side effects, and also synthesize substituted benzimidazole rings.