사료 첨가용 생균제를 위한 Probiotics 유산간균의 분리 및 동정

이승배,최석호,Lee Seung-Bae,Choi Suk-Ho 한국축산식품학회 2006 한국축산식품학회지 Vol.26 No.1

한우와 홀스타인의 분변으로부터 MRS 배지와 LAPT 배지를 이용하여 무작위 선발법으로 54균주의 유산균을 1차로 분리하였다. 1차로 분리된 54균주에 대해 내담즙성이 우수한 10균주를 분리한 다음 내산성을 조사한 결과 인공위액 pH 2.5에서 LS1, LS15 및 LL6 균주가 각각 66.5%, 82.6% 및 80.7%의 생존율을 나타내었다. Sal. typhimurium, Sta. aureus 및 Cl. perfringens의 병원균에 대해 가장 큰 항균력을 보인 균주는 LL6와 LL7이었다. API CHL kit로 동정한 결과 LS1, LS2 및 LMI 균주는 모두 L. fermentum, LL6와 LL7 균주는 L. acidophilus, LS3 균주는 L. plantarum으로 각각 동정되었고, 나머지 4균주는 Lactobacillus spp. 로 동정되어 분리된 10균주 모두 안전성 있는 유산간균임을 확인하였다. 10종류의 항생제에 대한 내성을 조사한 결과 ampicillin, amoxicillin과 erythromycin에 대해서는 감수성이 있으나 colistin과 ciprofloxacin에 대해 모두 내성을 나타내었다. LB1, LL6 및 LL7 균주는 gentamicin과 neomycin에 대해 내성을 보여 주었다. 분리 동정된 균주 중에 내산성, 내담즙성 및 병원성 균에 대한 특성을 기준으로 판단할 경우 probiotic 유산균으로 사용 가능성이 높은 것은 LL6인 L. acidophilus로 나타났다. Fifty four acid-resistant and bile-resistant isolates of lactic acid bacteria were initially isolated from the faces of Korea native cattle and Holstein using MRS agar and LAPT agar, and ten strains with superior activity against bile salt were finally selected LS1, LS15, and LL6 isolates showed survival of 66.5%, 82.6% and 80.7% against the simulated stomach liquid(pH 2.5), respectively. LL6 and LL7 isolates had the highest inhibitory activities against the pathogenic bacteria such as Salmonella typhimurium, Staphylococcus aureus, and Clostridium perfringens. By using API 50 CHL kit LS1, LS2 and LM1 isolates were identified as a L. fermentum. LL6 and LL7 isolates as a L. acidophilus, and LS3 isolate as a L. plantarum. The other four isolates belong to genus Lactobacillus. All the isolates tested were sensitive to some antibiotics such as ampicillin, amoxicillin and erythromycin, but resistant to colistin and ciprofloxacin. LB1, LL6 and LL7 isolates were resistant to gentamicin and neomycin. Especially, the LL6 isolate showed the highest resistance to both of the simulated stomach liquid and bile salt, in addition to the highest inhibitory activities against Sal. typhimurium, Staph. aureus and Cl. perfringens.

Birnessite와 Hydroxyapatite에 의한 납과 카드뮴 오염퇴적토의 독성저감 평가

이승배,정재웅,김영진,남경필,Lee, Seung-Bae,Jung, Jae-Woong,Kim, Young-Jin,Nam, Kyoung-Phile 한국지하수토양환경학회 2012 지하수토양환경 Vol.17 No.4

The success of stabilization treatment in heavy metal contaminated sediment depends on the heavy metal bioavailability reduction through the sequestration of the heavy metals. This study was performed to assess the changes in the bioavailability of Pb or Cd in the Pb or Cd contaminated sediments by using birnessite and hydroxyapatite as stabilizing agents. The toxicity tests were carried out using a microorganism (Vibrio fischeri), an amphipod (Hyalella azteca) and an earthworm (Eisenia foetida). With Vibrio fischeri, the toxicities of both Pb and Cd were reduced by more than ten times in the presence of birnessite and hydroxyapatite compared to that of in the absence of birnessite and hydroxyapatite. The concentrations of Pb and Cd in the contaminated sediments were lethal to Hyalella azteca, however, in the presence of birnessite and hydroxyapatite more than 90%, on average, of Hyalella azteca survived. With Eisenia foetida, the bioaccumulated concentrations of both Pb and Cd were reduced by more than 75%, on average, lower with the addition of birnessite and hydroxyapatite to the contaminated sediments. These results show that the addition of birnessite and hydroxyapatite can reduce the bioavailability of Pb and Cd in contaminated sediments. In addition, the in situ and ex situ performance of birnessite and hydroxyapatite as stabilizing agents can be verified using the toxicity tests with Hyalella azteca and Eisenia foetida, respectively.

축대칭 물체의 경계층 유동소음에 대한 실험적 연구(II) - 전두부 천이제어 및 방사소음 -

이승배,김휘중,권오섭,이상권,Lee, Seung-Bae,Kim, Hooi-Joong,Kwon, O-Sup,Lee, Sang-Kwon 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.10

The oscillatory excitation with a Strouhal number of 2.65 ncar the stagnation zone of hemispherical nose model was employed to control the laminar separation bubble and the transition to turbulence. The effects of oscillatory excitation upon the separation bubble and the transition were addressed in terms of kurtosis/skewness and time-frequency analyses. The measured noise spectrum of radiated sound from the turbulent boundary layer on the axi-symmetric infinite cylinder is compared with that by Sevik's wave-number white approximations. The noise sources in TBL on axi-symmetric cylinder and the caling of their far-field sound are also discussed.

축대칭 물체의 경계층 유동소음에 대한 실험적 연구 ( I ) - 축대칭 물체 전두부 및 실린더 벽면 섭동압력 -

이승배,김휘중,권오섭,이상권,Lee, Seung-Bae,Kim, Hooi-Joong,Kwon, O-Sup,Lee, Sang-Kwon 대한기계학회 2000 大韓機械學會論文集B Vol.24 No.7

The axisymmetric bodies considered in this study have hemispherical and ellipsoidal noses. The near-field pressure fluctuations over each nose model at $Re_D=2.43{\times}10^5$ were investigated in the laminar separation region and developing turbulent boundary layers using a 1/8' pin-holed microphone sensor. The wall pressure fluctuations were also measured in an axisymmetric boundary layer on a cylinder parallel to mean flow at a momentum thickness Reynolds number of 850 and a boundary layer thickness to cylinder radius ratio of 1.88.

Duplex PCR을 이용한 유제품 안에 있는 산양유와 우유의 신속한 동정에 대한 연구

이승배,최석호,Lee, Seung-Bae,Choi, Suk-Ho 한국축산식품학회 2009 한국축산식품학회지 Vol.29 No.5

A duplex PCR technique was applied for specific identification of cow and goat milk in milk products by using primers targeting the mitochondrial 12S rRNA gene. Duplex PCR using primers specific for cow and goat generated specific fragments of 223bp and 326bp from cow and goat milk DNA, respectively. Duplex PCR was applied to 15 milk products purchased from the market to verify label statements. The labeling statements of four market milk products, three yoghurt products, and one whole milk powder product were confirmed in the duplex PCR. The labeling statements of five of seven infant milk powder products were also confirmed by duplex PCR but the other two products were shown to be contaminated with either cow or goat milk. The proposed duplex PCR provides a rapid and sensitive approach to detection of as little as 0.1% cow milk in goat milk and one-step detection of cow or goat milk in milk products.

철근콘크리트 보에서의 최대 균열폭에 대한 실험적 고찰

이승배(Lee, Seung Bae),윤형재(Yoon, Hyung Jae),김상식(Kim, Sang Sik),김강수(Kim, Kang Su) 한국콘크리트학회 2007 한국콘크리트학회 학술대회 논문집 Vol.2007 No.5

프리스트레스트 슬래브를 이용한 평면확장공법에 대한 연구

이승배(Lee, Seung Bae),김상식(Kim, Sang Sik),최광호(Choi, kwang Ho),전병갑(Jeon, Byung Gab),이정윤(Lee Jung yoon) 한국콘크리트학회 2007 한국콘크리트학회 학술대회 논문집 Vol.2007 No.5

O2O 배달 앱 서비스 이용자의 충성의도에 미치는 영향에 관한 연구 ; 기술수용, 가치기반 및 서비스 품질 모델의 통합적 관점에서

이승배 ( Lee Seung-bae ) 한국경영공학회 2021 한국경영공학회지 Vol.26 No.1

Purpose The purpose of this study is to present what elements are necessary to increase loyalty intentions from the integrated perspective of UTAUT, VAM, SERVQUAL models in order to examine the effects of intentions to accept new technologies and the service quality of delivery apps on the perceived value and loyalty intentions in analyzing the delivery app market, which is rapidly growing in the food delivery order market. Methods A total of 243 samples were obtained from consumers who had used delivery apps through a Google online questionaire survey, and IBM SPSS 26 was used for statistical testing. In order to test the study hypotheses, a three-step mediated regression analysis was performed for a multiple regression analysis and a mediated effect analysis. Results First, it was found that effort expectancy, personal innovativeness, and social influence had significant effects on perceived value. Second, effort expectancy, personal innovativeness, and social influence were shown to have significant effects on loyalty intentions. Third, responsiveness, ease of use, and reliability were found to have significant effects on perceived value. Fourth, ease of use and reliability were found to have significant effects on loyalty intention, but responsiveness was shown to have no significant effect on loyalty intentions. Fifth, perceived value was found to have significant effects on loyalty intentions, and finally, perceived value was shown to have no mediating effect among technology acceptance, service quality, and loyalty intentions. Conclusion Along with discussions on how users will actively accept and use the delivery app services using new information technologies, the organic combination of the simplicity of the ordering process, the security of personal information, and the reliability given by system stability will lead to more positive perceived value consisting of benefits and pleasure so that the customers who currently use delivery app services can be secured as long-term loyal customers who intend to use the services more consistently.

중학교 체육교과서의 영역형 경쟁 활동 내용구성 체제 분석

이승배(Seung Bae Lee),박윤혁(Yeoun Hyuk Park) 한국스포츠교육학회 2011 한국스포츠교육학회지 Vol.18 No.1

본 연구는 2007년 개정된 체육과 교육과정에 따라 개발된 중학교 체육교과서의 영역형 경쟁 활동에 대한 내용 구성 체제를 분석하는 데 그 목적이 있다. 이러한 연구 목적에 도달하기 위해 총 7개 출판사의 검정·발간된 9종의 중학교 체육교과서 자료를 수집하였다. 수집된 자료를 분석하기 위해서 교육과정 상에 제시된 영역형 경쟁 활동의 내용 요소인 역사와 과학적 원리, 경기 방법·기능·전략, 리더십과 팔로십, 전통 스포츠와 뉴 스포츠의 경기 감상이라는 4가지 측면에 대한 내용의 기술 방식 및 조직 형태를 분석의 준거로 설정하였다. 분석 결과는 다음과 같다. 첫째, 9종의 체육교과서에 기술된 영역형 경쟁 활동의 특징을 분석한 결과, 각각의 교과서는 교육과정 상에 제시된 영역형 경쟁 활동의 내용 요소를 구체적으로 제시하고 있었다. 그러나 내용구성 체제에 있어 다소 차이가 있는 것으로 나타났다. 둘째, 9종 중학교 체육교과서의 영역형 경쟁 활동에 대한 내용구성 체제를 분석한 결과, 중학교 체육교과서의 영역형 경쟁 활동은 세 가지 유형의 내용구성 체제로 범주화 되었다. 즉, 교육과정 상의 학습 내용 요소를 종합적으로 제시하고 있는 ‘통합형’, 학습 내용 요소를 부분적으로 종합하고 있는 ‘부분통합형’, 그리고 학습 내용 요소를 분절적으로 제시하고 있는 ‘병렬형’으로 분석되었다. The purpose of this study is to examine the content organization of invasion competition included in middle school physical education(PE) textbook developed in accordance to the national 2007` physical education curriculum. In order to achieve our research objective, data were collected from nine authorized textbooks and the description routine and structural layout of the four key content elements of invasion competition were selected as a criteria for the research so as to analyse the collected data. The research results are as follows: First, although there were some minor differences as to the content organization of respective PE textbooks, each of the textbooks clearly presented content elements of invasion competition as stated in the national 2007` physical education curriculum. Secondly, as a result of analysing the respective textbooks` content organization, it was found that invasion competition stated in middle school PE textbooks could be categorized into three models of content organization - ``integrated``, ``partly-integrated``, ``parallel``.

인장증강효과를 고려한 철근콘크리트 단순보와 연속보의 유효 단면2차모멘트에 대한 실험적 검증

이승배(Lee, Seung Bae),윤형재(Yoon, Hyeong Jae),김강수(Kim, Kang Su),김상식(Kim, Sang Sik) 한국콘크리트학회 2008 한국콘크리트학회 학술대회 논문집 Vol.2008 No.11