• 펄프종이기술
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• 제44권2호
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• pp.42-48
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• 2012

In the 21st century, the printing industry as well as the IT industry has made rapid development. However, despite these technological advancement in the printing industry, it is still harmful for the environment, the state regulation is insufficient. Therefore, we studied the printability for the existing heat-set web inks and the newly created phenol-free eco-inks. This ink was made by reacting rosin and unsaturated dibasic acid and ester reactant, ester reactant was used instead of phenol. Printability test were used in the IGT printability tester. Experimental conditions, the temperature $22.7^{\circ}C$, humidity 57% under conditions of 0.6cc of ink supply, the print speed 1m/sec, pressures were set at 250N. As results of this study, we were able to get the following conclusions. The properties of phenol-free ink is the same as the existing inks. So we are thought to improve some characteristics such as dispersion, able to replace the existing ink.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.51-56
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• 2019

Biofilms facilitate communication among microorganisms for nutrients and protect them from predators and harmful chemicals such as antibiotics and detergents. Biofilms can also act as cores for the development of clogs in many agricultural irrigation systems and in porous media. In this study, we deployed glass units at a depth of 20 m below the ground surface in the groundwater-surface water mixing zone, and retrieved them after 4 months to investigate the potential colonization of indigenous microbial community and possible mineral-microbe assemblages. We observed the periodic formation of microbial colonies by fluorescence dye staining and microscopy, and analyzed the composition of the microbial community in both the mineral-microbe aggregates and groundwater, by next generation sequencing of the 16S rRNA gene amplicons using MiSeq platform. During the course of incubation, we observed an increase in both the mineral-microbe aggregates and content of extracellular polymeric substances. Interestingly, the microbial community from the aggregates featured a high abundance of iron redox-related microorganisms such as Geobacter sp., Comamonadaceae sp., and Burkholderiales incertae sedis. Therefore, these microorganisms can potentially produce iron-minerals within the sediment-microbe-associated aggregates, and induce biofilm formation within the groundwater borehole and porous media.

• 한국콘텐츠학회논문지
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• 제21권1호
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• pp.615-625
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• 2021

본 연구는 아동의 이웃 및 대중매체경험이 친사회적 행동에 어떠한 영향을 미치는지와 공감능력이 이들 간의 관계를 매개하는지를 살펴보고자 하였다. 이를 위해 충북지역 초등학교 5, 6학년을 할당표집하여 설문조사를 실시하였으며 419명의 자료를 SPSS로 분석하였다. 연구결과 여아가 남아보다, 5학년이 6학년보다 긍정적 대중매체경험, 공감능력, 그리고 친사회적 행동이 높은 것으로 나타났다. 또한 경제수준을 상으로 인식한 집단이 중상이나 중하로 인식한 집단보다 지역사회환경만족도, 공감능력, 친사회적 행동이 유의하게 높게 나타났다. 회귀분석결과 이웃 및 긍정적 대중매체경험이 공감능력과 친사회적 행동에 유의한 영향을 미쳤고 특히 긍정적 대중매체경험이 가장 큰 영향을 미치는 것으로 나타났다. 마지막으로, 이웃경험 중 지역사회환경만족도와 긍정적 대중매체경험은 아동의 친사회적 행동에 직접적인 영향을 미칠 뿐만 아니라 공감능력을 통해 간접적인 영향을 미치는 것으로 나타나 공감능력의 부분매개효과가 확인되었다. 이러한 연구결과를 바탕으로 아동의 공감능력과 친사회적 행동 증진을 위한 실천적 개입 방안을 제시하였다.

• Biomolecules & Therapeutics
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• 제7권4호
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• pp.385-389
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• 1999

The injibitory effect of Bacillus licheniformis AJ isolated from genitourinary normal flora as a new probiotics on the growth of diarrheal pathogens was studied. This B. licheniformis AJ inhibited the growth of E.coli O-157. Salmonella typhi and Shigella sonnei as well as the infectivity of rotavirus. However, it did not inhibit the growth of Helicobacter pyloriand human intestinal bacteria although it inhibited the harmful enzyme activity of human intestinal bacteria. B. licheniformis AJ seems to excret heat-lable growth-inhibitory protein, bacteriocin, into the media. These results suggest that B. lichenoformis AJ could be used as a new type of probiotics.

• 센서학회지
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• 제27권3호
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• pp.143-149
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• 2018

In this paper, we introduce an edge-spike modulation method for visible light communication (VLC). This method is effective in preventing LED flicker and 120 Hz noise interference in base-band VLC. In the VLC transmitter, edge-spikes are generated by passing the digital data through a simple RC-high pass filter (HPF). The LED modulation of the edge-spikes does not change the average power of the LED light; thus it prevents LED flicker. In the VLC receiver, the 120 Hz noise from other lighting lamps is easily eliminated by RC-HPF, while the edge-spike signal is detected normally. In our experiment, the message of an air-quality sensor was successfully transmitted using edge-spike modulation. This structure is useful in constructing, e.g., wireless gas monitoring sensor systems to warn and prevent harmful gas leakage accidents in buildings using LED light.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.453-458
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• 1994

Intestinal microbial flora comprise one third of the large intestinal contents in human. They play a significant effects through beneficial and harmful action on the human health. This is the first study which examined the composition of the microflora of the general population in Korea. Bacteroides, Bifidobacterium, Eubacterium, Peptostreptococcus, Lactobacillus, Streptococcus, Escherichia coli, Staphylococcus, Clostridium perfringens, total aerobic bacteria and total anaerrobic bacteria were counted using various selective and non-selective media. Among the bacteria studied the number of Bifidobacterium were greatest in breast-fed infants(30-90 days old), whereas Streptocuccus and Bifidobacterium in bottle-fed infants. In 20-40 age group Bacteroides were predominant followed by Bifidobacterium and Eubacterium. In early group(over 65 years old) Bacteroides were predominant followed by Eubacterium and bifidobacterium. The frequency and number of Cl. perfringens were highest in dlderly group. These results confirm that the microfloral pattern in large intestine change during the life cycle of humans.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 춘계학술대회
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• pp.11-18
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• 2008

This research modified the checklist used in the universities in USA, England and Korea considering the current situation of Korea, and conducted case studies upon each section of appointed chemical laboratories based on 4M criteria, which stands for Machine, Media, Man and Management. The purpose of the studies is to assess how dangerous the laboratories are and to contribute to prevention of accidentsin the laboratories as well as reducing loss of lives and property. The result of this research found out the harmful and hazardous factors based on the 4M-type checklist and predicted the dangerousness as it multiplies possible frequency by intensity. Protective equipment, safety facilities in laboratories, emergency exit and compressed gas cylinder are found to be more dangerous, so the result shows that it is desirable to improve ventilation, safety facilities and circumstances of the laboratory through the investment.

• Advances in environmental research
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• 제5권4호
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• pp.263-282
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• 2016

Contaminant transport in groundwater induces major threat and harmful effect on the environment; hence, the fate of the contaminant migration in groundwater is seeking a lot of attention. In this paper a two dimensional numerical flow and transport model through saturated layered soil is developed. Groundwater flow and solute transport has been simulated numerically using proposed model. The model implements the finite volume time splitting method to discretize the main equations. The performance, accuracy and efficiency of the out coming numerical models have been successfully examined by two test cases. The verification test cases consist of two-dimensional, groundwater flow and solute transport. The final purpose of this paper is to discuss and compare the shape of contaminant plume in homogeneous and heterogeneous media with different soil properties and control of solute transport using a zone for minimizing the potential of groundwater contamination; furthermore, this model leads to select the effective and optimum remedial strategies for cleaning the contaminated aquifers.

• 공업화학
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• 제20권5호
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• pp.561-564
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• 2009

화학적 바인더를 사용하여 활성탄을 고정화시킨 필터 여재(filter media)와 바인더를 사용하지 않고 니들펀치 공정으로 제조한 필터여재를 비교해 보았다. 제조된 콤비네이션 필터는 실차의 내용적과 비슷한 크기의 챔버 내부의 차량용 송풍기에 장착하여 가스제거 효과를 평가하여 보았다. 화학적 바인더를 사용한 캐빈에어필터는 바인더에 의해 활성탄의 흡착기공이 막혀 아세트알데히드 제거 효과가 감소하리라는 예측과 반대로 니들펀칭 공정으로 제조한 필터에 비해 아세트알데히드 1 min 및 30 min 제거효율이 더 높게 나타났다. 니들펀칭 공정에 따르면 활성탄의 소수성결합력(hydrophobic interaction)으로 인해 화학적 바인더를 사용한 캐빈에어필터보다 공극면적(void area)이 상대적으로 더 넓은 것으로 나타났다.

• 한국콘텐츠학회논문지
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• 제22권3호
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• pp.273-284
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• 2022

유튜브 사용량은 계속해서 증가하고 있으며, 유튜브를 가장 많은 시간 사용하는 연령대는 10대로 조사되고 있다. 어린이·청소년이 유해한 콘텐츠에 노출되는 것을 막는 것은 현실적으로 불가능하므로, 유튜브 콘텐츠를 건강하게 선택하고 활용하는 역량을 키워내는 것이 근본적인 해결책이 될 수 있다. 이에 본 연구에서는 디지털 네이티브 세대를 위한 유튜브 리터러시란 무엇인지 규명하고, 공통적으로 고려해야 할 기준을 마련하고자 하였다. 본 연구는 유튜브 리터러시 역량의 정의를 구체화하고, 어린이·청소년의 유튜브 플랫폼 활용 안내·지도 시 활용할 수 있는 체크리스트를 개발하는 것을 목적으로 한다. 이를 위하여 선행 연구와 해외사례 분석을 바탕으로 개념적 정의 및 체크리스트를 개발하였으며, 전문가 및 교육자 검토를 통하여 타당성을 확보하였다. 최종적으로 개발한 체크리스트는 미디어 접근, 비판적 이해, 미디어 참여, 윤리적 활용 4개 범주의 10개 역량, 23문항을 포함한다.