Structural transition induced by cage-dependent guest exchange in CH₄ + C₃H₈ hydrates with CO₂ injection for energy recovery and CO₂ sequestration

Lee, Yohan,Choi, Wonjung,Seo, Young-ju,Lee, Joo Yong,Lee, Jaehyoung,Seo, Yongwon Elsevier 2018 APPLIED ENERGY Vol.228 No.-

<P><B>Abstract</B></P> <P>This study investigated a structural transition induced by cage-dependent guest exchange in the CH<SUB>4</SUB> + C<SUB>3</SUB>H<SUB>8</SUB> hydrate with CO<SUB>2</SUB> injection for CH<SUB>4</SUB> recovery and CO<SUB>2</SUB> sequestration. The influence of the CO<SUB>2</SUB> replacement on the crystalline structure of initial CH<SUB>4</SUB> + C<SUB>3</SUB>H<SUB>8</SUB> hydrates and the cage-dependent distribution of guest molecules were quantitatively investigated using powder X-ray diffraction, <SUP>13</SUP>C nuclear magnetic resonance spectroscopy, and gas chromatography. The quantitative analyses demonstrated that the CO<SUB>2</SUB> occupation caused the depletion of C<SUB>3</SUB>H<SUB>8</SUB> molecules in the large 5<SUP>12</SUP>6<SUP>4</SUP> cages of structure II hydrates, thereby resulting in the subsequent transformation into CO<SUB>2</SUB>-rich sI hydrates and the coexistence of structure I and structure II hydrates after the replacement. The guest-exchange behavior observed from time-dependent Raman spectra indicated that the replacement rate was increased with an increase in pressure of injected CO<SUB>2</SUB> and that the extent of the replacement was enhanced at higher pressure of injected CO<SUB>2</SUB>. Overall experimental evidence of the partial structural-transition replacement suggests that CO<SUB>2</SUB> molecules first occupied structure II hydrates predominantly with the rapid guest exchange at the surface and that the initial structure II hydrates were subsequently converted to the CO<SUB>2</SUB>-rich structure I hydrates from the surface to the inner side. Precise identification of the mechanism responsible for the partial structural transition occurring in the CH<SUB>4</SUB> + C<SUB>3</SUB>H<SUB>8</SUB> - CO<SUB>2</SUB> replacement will be very helpful in developing a strategy for actual CO<SUB>2</SUB> injection into structure II gas hydrate reservoirs for energy recovery and CO<SUB>2</SUB> sequestration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The guest exchange behavior during replacement was quantitatively investigated. </LI> <LI> The CO<SUB>2</SUB> occupation induced the depletion of C<SUB>3</SUB>H<SUB>8</SUB> in the large 5<SUP>12</SUP>6<SUP>4</SUP> cages of sII. </LI> <LI> The partial structural transition occurred in the CH<SUB>4</SUB> + C<SUB>3</SUB>H<SUB>8</SUB> - CO<SUB>2</SUB> replacement. </LI> <LI> The replacement was more significant at higher pressure of injected CO<SUB>2</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Combination of Hydrophobic Filtration and Enrichment Methods for Detecting Bacillus cereus in Fresh-Cut Cabbage

Lee, Sujung,Choi, Yukyung,Lee, Heeyoung,Kim, Sejeong,Lee, Jeeyeon,Ha, Jimyeong,Oh, Hyemin,Lee, Yewon,Kim, Yujin,Yoon, Yohan,Lee, Soomin The Korean Society of Food Hygiene and Safety 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/mL이 되도록 증균배지에 접종하고 $30^{\circ}C$, $37^{\circ}C$, $42^{\circ}C$에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 $42^{\circ}C$에서 증균된 샘플($5.4{\pm}0.3Log\;CFU/mL$)과 $30^{\circ}C$에서 증균된 샘플($4.6{\pm}0.6Log\;CFU/mL$) 간 유의차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다. This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at $30^{\circ}C$, $37^{\circ}C$, and $42^{\circ}C$ to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at $42^{\circ}C$ than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.

Quantitative Microbial Risk Assessment for Campylobacter jejuni in Ground Meat Products in Korea

Lee, Jeeyeon,Lee, Heeyoung,Lee, Soomin,Kim, Sejeong,Ha, Jimyeong,Choi, Yukyung,Oh, Hyemin,Kim, Yujin,Lee, Yewon,Yoon, Ki-Sun,Seo, Kunho,Yoon, Yohan Korean Society for Food Science of Animal Resource 2019 한국축산식품학회지 Vol.39 No.4

This study evaluated Campylobacter jejuni risk in ground meat products. The C. jejuni prevalence in ground meat products was investigated. To develop the predictive model, survival data of C. jejuni were collected at $4^{\circ}C-30^{\circ}C$ during storage, and the data were fitted using the Weibull model. In addition, the storage temperature and time of ground meat products were investigated during distribution. The consumption amount and frequency of ground meat products were investigated by interviewing 1,500 adults. The prevalence, temperature, time, and consumption data were analyzed by @RISK to generate probabilistic distributions. In 224 samples of ground meat products, there were no C. jejuni-contaminated samples. A scenario with a series of probabilistic distributions, a predictive model and a dose-response model was prepared to calculate the probability of illness, and it showed that the probability of foodborne illness caused by C. jejuni per person per day from ground meat products was $5.68{\times}10^{-10}$, which can be considered low risk.

Development of User-Friendly Modeling Software and Its Application in Processed Meat Products

Lee, Heeyoung,Lee, Panho,Lee, Soomin,Kim, Sejeong,Lee, Jeeyeon,Ha, Jimyeong,Choi, Yukyung,Oh, Hyemin,Yoon, Yohan The Korean Society of Food Hygiene and Safety 2018 한국식품위생안전성학회지 Vol.33 No.3

본 연구에서는 육제품의 다양한 조건(포장, 저장온도, 염농도, 아질산염농도)에서의 식중독세균의 생장을 예측하는소프트웨어를 예측미생물학에 대한 지식이 부족한 비전문가도 손쉽게 이용할 수 있도록 개발하였다. 육제품에서의 식중독세균예측소프트웨어(FAME: Foodborne bacteria Animal product Modeling Equipment)는 Javascript와 HTML을 이용하여 개발하였으며, 육제품에 대한 카이네틱모델과 확률모델을 포함하고있다. FAME에서는 검증(validation) 기능을 포함하고 있으며, FAME에 탑재 되어있는 예측모델의 수식을 자유롭게 수정할 수 있도록 고안 하였다. FAME에는 포장조건, 온도, 염농도, 아질산염농도 조합에 따라 실험한 데이터를 카이네틱모델(5,400 데이터)과 확률모델(345,600 데이터)에 탑재하였다. 사용자가 FAME을 이용하여 육제품의 제조 조건을 소프트웨어에 입력하면, 시간에 따른 식중독세균의 생장패턴과 생장확률이 즉시 계산 되어진다. 따라서 예측 미생물학에 대한 전문 지식이 없는 비전문가라고 하더라도 FAME을 이용하여 직접 실험을 하지 않고도 육제품에서의 식중독세균의 생장을 쉽고 빠르게 예측할 수 있어, 육가공분야에서 매우 유용하게 사용되어 질 수 있을 것으로 판단된다. The objective of this study was to develop software to predict the kinetic behavior and the probability of foodborne bacterial growth on processed meat products. It is designed for rapid application by non-specialists in predictive microbiology. The software, named Foodborne bacteria Animal product Modeling Equipment (FAME), was developed using Javascript and HTML. FAME consists of a kinetic model and a probabilistic model, and it can be used to predict bacterial growth pattern and probability. In addition, validation and editing of model equation are available in FAME. The data used by the software were constructed with 5,400 frankfurter samples for the kinetic model and 345,600 samples for the probabilistic model using a variety of combinations including atmospheric conditions, temperature, NaCl concentrations and $NaNO_2$ concentrations. Using FAME, users can select the concentrations of NaCl and $NaNO_2$ meat products as well as storage conditions (atmosphere and temperature). The software displays bacterial growth patterns and growth probabilities, which facilitate the determination of optimal safety conditions for meat products. FAME is useful in predicting bacterial kinetic behavior and growth probability, especially for quick application, and is designed for use by non-specialists in predictive microbiology.

Electrically tunable multifunctional metasurface for integrating phase and amplitude modulation based on hyperbolic metamaterial substrate

Lee, Yohan,Kim, Sun-Je,Yun, Jeong-Geun,Kim, Changhyun,Lee, Seung-Yeol,Lee, Byoungho The Optical Society 2018 Optics express Vol.26 No.24

Experimental Verification of Methane–Carbon Dioxide Replacement in Natural Gas Hydrates Using a Differential Scanning Calorimeter

Lee, Seungmin,Lee, Yohan,Lee, Jaehyoung,Lee, Huen,Seo, Yongwon American Chemical Society 2013 Environmental science & technology Vol.47 No.22

<P>The methane (CH<SUB>4</SUB>) – carbon dioxide (CO<SUB>2</SUB>) swapping phenomenon in naturally occurring gas hydrates is regarded as an attractive method of CO<SUB>2</SUB> sequestration and CH<SUB>4</SUB> recovery. In this study, a high pressure microdifferential scanning calorimeter (HP μ-DSC) was used to monitor and quantify the CH<SUB>4</SUB> – CO<SUB>2</SUB> replacement in the gas hydrate structure. The HP μ-DSC provided reliable measurements of the hydrate dissociation equilibrium and hydrate heat of dissociation for the pure and mixed gas hydrates. The hydrate dissociation equilibrium data obtained from the endothermic thermograms of the replaced gas hydrates indicate that at least 60% of CH<SUB>4</SUB> is recoverable after reaction with CO<SUB>2</SUB>, which is consistent with the result obtained via direct dissociation of the replaced gas hydrates. The heat of dissociation values of the CH<SUB>4</SUB> + CO<SUB>2</SUB> hydrates were between that of the pure CH<SUB>4</SUB> hydrate and that of the pure CO<SUB>2</SUB> hydrate, and the values increased as the CO<SUB>2</SUB> compositions in the hydrate phase increased. By monitoring the heat flows from the HP μ-DSC, it was found that the noticeable dissociation or formation of a gas hydrate was not detected during the CH<SUB>4</SUB> – CO<SUB>2</SUB> replacement process, which indicates that a substantial portion of CH<SUB>4</SUB> hydrate does not dissociate into liquid water or ice and then forms the CH<SUB>4</SUB> + CO<SUB>2</SUB> hydrate. This study provides the first experimental evidence using a DSC to reveal that the conversion of the CH<SUB>4</SUB> hydrate to the CH<SUB>4</SUB> + CO<SUB>2</SUB> hydrate occurs without significant hydrate dissociation.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2013/esthag.2013.47.issue-22/es403542z/production/images/medium/es-2013-03542z_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es403542z'>ACS Electronic Supporting Info</A></P>

VII. When Comparative Negligence Is Not Allowed Due to Principle of Good Faith Supreme Court, 2007Da88644, Decided May 15, 2008 [Price of Purchase and Sale]

( Yohan Lee ),( Ahlim Ha ),( Hyunseo Lee ),( Unhyung Lee ) 고려대학교 법학연구원 2017 Korea University Law Review Vol.21 No.-

Measurement of Dissociation Enthalpy for Gas Hydrates Using in-situ High pressure DSC

Seungmin Lee(이승민),Jin Woo Lee(이진우),Kyeong Nam Park(박경남),Sang Yeon Hong(홍상연),Yunju Kim(김연주),Yohan Lee(이요한),Ju Dong Lee(이주동),Yongwon Seo(서용원) 한국신재생에너지학회 2013 한국신재생에너지학회 학술대회논문집 Vol.2013 No.05

메탄-연소배가스 치환 과정의 해리엔탈피 측정

이요한(Yohan Lee),김연주(Yunju Kim),이승민(Seungmin Lee),이재형(Jaehyung Lee),서용원(Yongwon Seo) 한국신재생에너지학회 2012 한국신재생에너지학회 학술대회논문집 Vol.2012 No.11

Combination of Hydrophobic Filtration and Enrichment Methods for Detecting Bacillus cereus in Fresh-Cut Cabbage

Sujung Lee,Yukyung Choi,Heeyoung Lee,Sejeong Kim,Jeeyeon Lee,Jimyeong Ha,Hyemin Oh,Yewon Lee,Yujin Kim,Yohan Yoon,Soomin Lee 한국식품위생안전성학회 2018 한국식품위생안전성학회지 Vol.33 No.5

본 연구에서는 신선편이 양배추 내 Bacillus cereus의 최 적 증균 온도를 선정하고 증균배양액에 소수성필터를 적용하여 multiplex PCR의 검출률을 확인하였다. B. cereus 증균온도는 B. cereus 균주 5 개를 혼합하여 1 Log CFU/ mL이 되도록 증균배지에 접종하고 30oC, 37oC, 42oC에서 증균한 뒤 3시간 간격으로 MYP agar에 도말한 후 계수하여 선정하였다. 소수성필터 미적용 그룹은 B. cereus 균 주 5 개를 혼합하여 신선편이 양배추에 접종한 뒤 최적 증균온도에서 증균하였으며, 증균배양액을 가열하여 DNA 를 추출한 뒤 multiplex PCR을 진행하였다. 소수성필터 적용 그룹은 증균배양액을 소수성 필터에 적용하고 필터에 있는 균을 멸균증류수로 현탁한 뒤 가열하여 추출된 DNA 로 multiplex PCR을 진행하였다. 증균온도 확인 결과, 6시간 증균 시 42oC에서 증균된 샘플(5.4 ± 0.3 Log CFU/mL) 과 30oC에서 증균된 샘플(4.6 ± 0.6 Log CFU/mL) 간 유의 차가 확인되었다(p < 0.05). 소수성필터 적용 유무에 따른 multiplex PCR 결과, 1 Log CFU/g 접종된 샘플의 검출률이 소수성 필터 적용 전 60%(3/5)에서 100%(5/5)로 향상 되었다. 2 Log CFU/g 접종 샘플은 소수성필터 적용 전 80%(4/5)에서 소수성 필터 적용 후 100%(5/5)로 검출률이 증가하였으나, 3 Log CFU/g 접종 샘플은 소수성 필터 적용 전후 모두 100%(5/5)로 확인되었다. 이상의 결과를 통해 신선편이 양배추 내 B. cereus 검출 시 증균배양액에 소수성필터를 적용하고 multiplex PCR을 적용했을 때 신속하고 효율적인 검출이 가능할 것으로 판단된다. This study developed a rapid detection method for Bacillus cereus in fresh-cut cabbages. Fresh-cut cabbage samples were inoculated at 1-, 2- and 3-Log CFU/g, and pathogens were enriched in tryptic soy broth containing 0.15% polymyxin B at 30oC, 37oC, and 42oC to determine the detection limit and appropriate enrichment temperature for multiplex PCR detection. Enriched bacterial cells in enrichment broth were collected in a hydrophobic filter prior to DNA extraction for multiplex PCR. Filters were resuspended in distilled water, and DNA was extracted from the suspension. DNA samples were further analyzed by multiplex PCR. Detection limit of multiplex PCR was 5-Log CFU/mL. B. cereus cell counts were higher (P < 0.05) at 42oC than other temperatures. Detection rate of 1-, 2-, and 3-Log CFU/g inoculated samples were 60%, 80%, and 100% after enrichment respectively. However, when enriched samples were filtered with hydrophobic membrane filter, detection rates became 100%, regardless of inoculation level. Results indicate a combination of enrichment with hydrophobic filtration improves rapid detection efficiency of B. cereus in fresh-cut cabbage by multiplex PCR.