암모니아산화세균 Brevundimonas diminuta의 분리 및 암모니아 산화 특성

권혁구,정준오,Kwon, Hyuk-Ku,Jung, Joon-Oh 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.4

The microorganism for ammonia gas removal was isolated from composting product. This was identified as Brevundimonas diminuta by morphological, biochemical characteristics study and 16S rDNA sequence analysis. Optimal incubation temperature for cell growth and oxidizing ability of $NH_4-N$ was $30^{\circ}C$ and optimal initial pH was 7. Glucose affected the growth of cell and the removal of $NH4^+$. The growth rate of the isolates were increased when grown in the presence of 0.05-1%(w/v) glucose in the selective medium and lurker increases in glucose concentration to 2% caused significant decreases in the cell growth and oxidizing ability of $NH4^+$.

가축 분변중의 항생제 내성균주의 분포에 관한 연구

권혁구,이장훈,김종규,Kwon, Hyuk-Ku,Lee, Jang-Hoon,Kim, Jong-Geu 한국환경보건학회 2012 한국환경보건학회지 Vol.38 No.2

Objectives: To estimate the multi-antibiotic resistant bacterial contaminant load discharged from livestock farms, we randomly selected livestock farms specializing in cattle, swine, and fowl and collected bacterial strains from domesticated animal feces and compost samples. Problems with resistance to antibiotics are becoming worldwide issues, and as the consumption of antibiotics appears to be excessive in Korea as well, the emergence of antibiotic resistant bacteria shows the possibility to cause potentially serious social problems. Methods: To monitor multi-antibiotic resistant bacterial constituents, aerobic bacteria and Escherichia coli were isolated from domesticated animal feces and compost. Antibiotic resistance testing was performed by the disc diffusion method using 13 different antibiotics. Results: Examining the degree of sensitivity to antibiotics of the aerobic bacteria originating from domesticated animal feces, fowl feces showed the highest distribution rate (35.5%), followed by swine feces compost (23.1%), swine feces (18.2%), cattle feces (14.9%), and cattle feces compost (8.2%). Antibiotic resistance tests of aerobic bacteria and E. coli originating from domestic animals feces resulted in 83.6% and 73.5% of each strain showing resistance to more than one antibiotic, respectively. Conclusions: These results suggest that increasing multi-antibiotic resistant bacteria in the environment has a close relation to the reckless use of antibiotics in livestock.

유기성 폐기물의 발생 악취 제거를 위한 Delftia sp.의 성장조건 최적화

권혁구,정준오,추덕성,이장훈,Kwon, Hyuk-Ku,Jung, Joon-Oh,Chu, Duk-Sung,Lee, Jang-Hoon 한국환경보건학회 2009 한국환경보건학회지 Vol.35 No.5

We isolated and identified a microorganism which was excellent for ammonia oxidation in the biological control of ammonia gas in odor producing materials from organic composting. The isolated strain was tested for growth characteristics and ammonia elimination efficiency under various conditions of temperature, pH, carbon concentration and ammonia concentration. The strain was isolated from a culture broth used in a $NO_2$ producing test with Griess-Ilosvay reagent. The results of 16S rRNA sequence from the isolated strain by using BLANST (Basic Local Alignment Search Tool) and confirming RDP (Ribosomal Database Project II) and ERRD (The European Ribosomal RNA Database) indicate that the strain is related to Delftia sp. UV-Spectrophotometer (Shimadzu, UVmini-1240) was used as a microbial growth test by measuring turbidity on OD660nm and ammonia concentration was measured by Spectrophotometer (HACH, DR-4000). The optimum growth culture conditions of the ammonia oxidizer Delftia sp. were $30^{\circ}C$, pH 7, glucose concentration 1.00% and $(NH_4)_2SO_4$ 0.5 g/l. Ammonia elimination efficiency was over 94% under the same conditions.

고효율 항균 필터의 항균력 평가에 관한 연구

권혁구(Kwon Hyuk-Ku),정진도(Jung Jin-Do),류해열(Ryu Hae-Ryeol),정우성(Jung Woo-Sung),박덕신(Park Duk-Sin) 한국철도학회 2002 한국철도학회 학술발표대회논문집 Vol.- No.-

Recently, interest in hygiene has been arouse in the health care field. Consequently, Filters with antibacterial agent applied to improve air quality by sterilizing bacteria, fungi, etc. We actually installed antibacterial air filter containing 2.5wt%Ag zeolite on the air intake route to air-conditioner in passenger car, and evaluated filter"s performance on antibacterial effect. By the microbe liquid spattering method, we found that the antibacterial air filter has notably sufficient antibacterial efficiency against standard strains and wild type strains. Antibacterial effect was observed at whole area of filter media by zone of inhibition test. The evaluation of microbe quantity was conducted through mixing dilution plate culture method. In comparison with ordinary filter, the amount of germs attached on antibacterial air filters was larger the amount of germs attached on ordinary filters was very small since ordinary filters contained less dust. In comparison in antibacterial air filter with thickness, the amount of germs attached on 9㎜ filter was smaller than that of on 6㎜ filter. i.e. thicker filter, superior efficiency.

솔더 인쇄조건 및 외적요소가 인쇄효율에 미치는 영향

하충수,권혁구,Ha, Chung-Soo,Kwon, Hyuk-Ku 한국마이크로전자및패키징학회 2018 마이크로전자 및 패키징학회지 Vol.25 No.1

최근 4차 산업혁명의 조류 하에 표면 실장 분야에서도 Smart Factory 구현을 위한 노력이 활발히 이루어지고 있다. 표면 실장 분야에서도 이러한 변화와 발 맞추어 많은 연구가 진행되고 있으며, 그중 핵심 공정이라 할 수 있는 솔더 인쇄 공정의 최적화에 대한 방법과 인쇄 효율에 영향을 미치는 인쇄 외적 요소에 대한 영향도를 분석하였다. 이 분석에는 설비에서 제공하는 Big Data를 활용하여 통계적 방법으로 접근하였고, 신뢰성 높은 결과와 함께 시뮬레이션을 통해 결과을 예측할 수 있는 가능성을 확인하였다. 이 연구가 실장 분야의 Smart Factory 구현에 조금이나마 기여가 되었으면 하는 바람이다. Under the 4th Industrial Revolution, implementation of Smart Factory in the field of surface mounting is an emerging issue. In the field of surface mounting, many researches are going on in line with these changes. Among them, we analyzed the method of optimizing the solder printing process which is a core process and the influence of the external factors affecting the printing efficiency. In this analysis, the Big Data provided by the SPI Machine was used to approach the statistical method, and the possibility of predicting the result through simulation with reliable results was confirmed. I hope this study contributes a little to the Smart Factory implementation.

새로운 염색폐수(染色廢水) 색도(色度) 제거(除去) 백색부후균(白色腐朽菌)의 분리(分離) 및 색도(色度) 제거(除去) 효과(效果)

남윤구,권혁구,이봉준,이장훈,Nam, Youn-Ku,Kwon, Hyuk-Ku,Lee, Bong-Joon,Lee, Jang-Hoon 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.4

For decolorization of synthetic dyes, One fungus(HUE05-1) which was isolated from textile wastewater collected from industrial complex in Korea showed excellent ability of removing synthetic dyes. This fungus was identified as Basidiomycetes species by Internal Transcribed Spacers (ITS) sequence. Isolated fungi. HUE05-1 completely decolorized all dyes in both solid and liquid condition. The decolorization results were Reactive Orange-16, 97.12%; Reactive Blue-19, 92.09%; Reactive Blue-49, 97.04%; Reactive Yellow-145, 95.53%; Acid Orange-10, 99.18%; Acid Violet-43, 98.73%; Acid Blue-350, 94.71% and Disperse Blue-106, 90.07%.

LCA 기법을 이용한 소맥분 생산 공정의 환경 영향 평가

추덕성,권혁구,김종규,이장훈,Chu, Duk-Sung,Kwon, Hyuk-Ku,Kim, Jong-Geu,Lee, Jang-Hoon 한국환경보건학회 2008 한국환경보건학회지 Vol.34 No.1

The life cycle assessment method for environmental impact assessment was used, in this study, to assess the production process of wheat flour which is the most important material in the food industry. Environmental impact assessments were compared between that of the Ministry of Environment, Republic of Korea (method I) with that of the Ministry of Commerce, Industry and Energy (method II). Life cycle inventories (LCI) was performed using internal and external databases and the production statistics database of company S. The procedure of life cycle impact assessment (LCIA) was followed in terms of classification, characterization, normalization and weighting to identify the key issues. The impact categories of method I were divided into 8 categories with consideration of : abiotic resources depletion, global warming, ozone depletion, photochemical oxidant creation, acidification and eutrophication. The impact categories of method II were divided into 10 categories with consideration of: abiotic resources depletion, global warming, ozone depletion, photochemical oxidant creation, acidification, eutrophication, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity and terrestrial ecotoxicity.

도심지역 인공호의 수질관리를 위한 지표세균에 관한 연구

추덕성,권혁구,이상은,이장훈,Chu, Duk-Sung,Kwon, Hyuk-Ku,Lee, Sang-Eun,Lee, Jang-Hoon 한국환경보건학회 2007 한국환경보건학회지 Vol.33 No.4

Distribution of fecal pollution indicator bacteria and environmental parameter were investigated of urban artificial lakes. An average concentration of temperature, pH, SS, DO, $COD_{Mn}$, T-P, T-N, Turbidity, Chl-a were $21.5^{\circ}C$, 8.07, 116.70 mg/l, 8.66 mg/l, 2.24 mg/1, 0.52 mg/l, 1.71mg/l, 80.54 NTU, and 52.12 mg/l respectively. From the results of bivariate correlation analysis, fecal contamination indicator bacteria were found to be mutually correlated. And turbidity and suspended solid were correlated. From the results of principal component analysis, four factors were extracted. And four factors of variance explained up to 81.5 percentage. Factor 1 was pollution pattern by fecal contamination, factor 2 was physical pollution pattern by pollution source, factor 3 was natural pollution by precipitation, and factor 4 was artificial pollution pattern by organism.

Al-Ni 전구체의 연소합성 발포에 의한 Al₃Ni 폼과 할로우 파이프의 복합구조체 제작 및 폼의 충진성과 기공상태 조사

한창석,진성윤,권혁구,Han, Chang-Suk,Jin, Sung-Yooun,Kwon, Hyuk-Ku 한국재료학회 2019 한국재료학회지 Vol.29 No.10

In order to develop a process for manufacturing a composite structure of an intermetallic compound foam and a hollow material, the firing and pore form of the Al-Ni precursor in a steel pipe are investigated. When the Al-Ni precursor is foamed in a hollow pipe, if the temperature distribution inside the precursor is uneven, the pore shape distribution becomes uneven. In free foaming, no anisotropy is observed in the foaming direction and the pore shape is isotropic. However, in the hollow pipe, the pipe expands in the pipe axis direction and fills the pipe. The interfacial adhesion between $Al_3Ni$ foam and steel pipe is excellent, and interfacial pore and reaction layer are not observed by SEM. In free foaming, the porosity is 90 %, but it decreases to about 80 % in the foam in the pipe. In the pipe foaming, most of the pore shape appears elongated in the pipe direction in the vicinity of the pipe, and this tendency is more remarkable when the inside pipe diameter is small. It can be seen that the pore size of the foam sample in the pipe is larger than that of free foam, because coarse pores remain after solidification of the foam because the shape of the foam is supported by the pipe. The vertical/horizontal length ratio expands along the pipe axis direction by foaming in the pipe, and therefore circularity is reduced.

그림자효과를 이용하여 증착한 타이타늄 박막의 미세구조 및 형상

한창석,진성윤,권혁구,Han, Chang-Suk,Jin, Sung-Yooun,Kwon, Hyuk-Ku 한국재료학회 2019 한국재료학회지 Vol.29 No.11

In order to observe the microstructure and morphology of porous titanium -oxide thin film, deposition is performed under a higher Ar gas pressure than is used in the general titanium thin film production method. Black titanium thin film is deposited on stainless steel wire and Cu thin plate at a pressure of about 12 Pa, but lustrous thin film is deposited at lower pressure. The black titanium thin film has a larger apparent thickness than that of the glossy thin film. As a result of scanning electron microscope observation, it is seen that the black thin film has an extremely porous structure and consists of a separated column with periodic step differences on the sides. In this configuration, due to the shadowing effect, the nuclei formed on the substrate periodically grow to form a step. The surface area of the black thin film on the Cu thin plate changes with the bias potential. It has been found that the bias of the small negative is effective in increasing the surface area of the black titanium thin film. These results suggest that porous titanium-oxide thin film can be fabricated by applying the appropriate oxidation process to black titanium thin film composed of separated columns.