Control of the red tide dinoflagellate <i>Cochlodinium polykrikoides</i> by ozone in seawater

Shin, Minjung,Lee, Hye-Jin,Kim, Min Sik,Park, Noh-Back,Lee, Changha Elsevier 2017 Water research Vol.109 No.-

<P><B>Abstract</B></P> <P>The inactivation of <I>C. polykrikoides</I>, a red tide dinoflagellate, by ozonation was investigated in seawater by monitoring numbers of viable and total cells. Parameters affecting the inactivation efficacy of <I>C. polykrikoides</I> such as the ozone dose, initial cell concentration, pH, and temperature were examined. The viable cell number rapidly decreased in the initial stage of the reaction (mostly in 1–2 min), whereas the decrease in total cell number was relatively slow and steady. Increasing ozone dose and decreasing initial cell concentration increased the inactivation efficacy of <I>C. polykrikoides</I>, while increasing pH and temperature decreased the cell inactivation efficacy. The addition of humic acid (a promoter for the ozone decomposition) inhibited the inactivation of <I>C. polykrikoides</I>, whereas bicarbonate ion (an inhibitor for the ozone decomposition) accelerated the <I>C. polykrikoides</I> inactivation. Observations regarding the effects of pH, temperature, humic acid, and bicarbonate ion collectively indicate that the inactivation of <I>C. polykrikoides</I> by ozonation is mainly attributed to oxidative cell damages by molecular ozone, rather than by hydroxyl radical, produced during the ozone decomposition. At high ozone dose (e.g., 5 mg/L), hypobromous acid formed by the reaction of bromide with ozone may partially contribute to cell inactivation. The use of ozone of less than 1 mg/L produced 0.75–2.03 μg/L bromate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ozonation rapidly inactivated <I>C. polykrikoides</I> in seawater via a two-stage process. </LI> <LI> Direct oxidation by ozone was responsible for the inactivation of <I>C. polykrikoides</I>. </LI> <LI> The use of ozone of less than 1 mg/L produced a negligible amount of bromate. </LI> </UL> </P>

Control of Cochlodinium polykrikoides, a red tide flagellate by ozone and hydrogen peroxide

Minjung Shin,Hye-Jin Lee,Noh-Back Park,Changha Lee 대한환경공학회 2015 대한환경공학회 학술발표논문집 Vol.2015 No.10

Abrupt Morphology Change upon Thermal Annealing in Poly(3-Hexylthiophene)/Soluble Fullerene Blend Films for Polymer Solar Cells

Shin, Minjung,Kim, Hwajeong,Park, Jiho,Nam, Sungho,Heo, Kyuyoung,Ree, Moonhor,Ha, Chang-Sik,Kim, Youngkyoo WILEY-VCH Verlag 2010 Advanced Functional Materials Vol.20 No.5

<P>The in situ morphology change upon thermal annealing in bulk heterojunction blend films of regioregular poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C<SUB>61</SUB> (PCBM) is measured by a grazing incidence X-ray diffraction (GIXD) method using a synchrotron radiation source. The results show that the film morphology—including the size and population of P3HT crystallites—abruptly changes at 140 °C between 5 and 30 min and is then stable up to 120 min. This trend is almost in good agreement with the performance change of polymer solar cells fabricated under the same conditions. The certain morphology change after 5 min annealing at 140 °C is assigned to the on-going thermal transition of P3HT molecules in the presence of PCBM transition. Field-emission scanning electron microscopy measurements show that the crack-like surface of blend films becomes smaller after a very short annealing time, but does not change further with increasing annealing time. These findings indicate that the stability of P3HT:PCBM solar cells cannot be secured by short-time annealing owing to the unsettled morphology, even though the resulting efficiency is high.</P> <B>Graphic Abstract</B> <P>The morphology of P3HT:PCBM blend films, one of the most widely used material blends in polymer solar cells, is monitored using in situ grazing angle X-ray diffraction (GIXD). The study reveals abrupt changes in the nanostructure with annealing time (see image, OOP = out-of-plane), which is in good agreement with variations in device performance (PCE = power conversion efficiency; FF = fill factor). <img src='wiley_img_2010/1616301X-2010-20-5-ADFM200901655-content.gif' alt='wiley_img_2010/1616301X-2010-20-5-ADFM200901655-content'> </P>

Influence of hole-transporting material addition on the performance of polymer solar cells

Shin, Minjung,Kim, Hwajeong,Nam, Sungho,Park, Jiho,Kim, Youngkyoo Royal Society of Chemistry 2010 ENERGY AND ENVIRONMENTAL SCIENCE Vol.3 No.10

<P>We report the effect of hole-transporting material (HTM) addition on the performance of polymer solar cells based on blends of poly(3-hexylthiophene) (P3HT) and soluble fullerene. <I>N</I>,<I>N</I>′-Diphenyl-<I>N</I>,<I>N</I>′-bis(3-methylphenyl)-[1,1′-diphenyl]-4,4′-diamine (TPD) was chosen as a HTM because it is one of the well-established HTMs despite its drawback of wide band gap (3.1 eV) for solar cell applications. Two specialized measurement systems, synchrotron radiation grazing incidence angle X-ray diffraction (GIXD) and phase-mode atomic force microscopy (AFM), were employed to understand the correlation between device performance and nanostructures of blend films. Results showed that the addition of 3–7 wt% TPD improved the short circuit current density of unannealed devices due to the improved P3HT crystallization induced by the presence of TPD molecules. Although the short circuit current density of the binary blend device was recovered to the highest value after thermal annealing, the improved fill factor of TPD-added ternary blend devices at the 3–7 wt% TPD content led to the slightly enhanced power conversion efficiency at 3 wt% TPD in spite of reduced optical absorption in the ternary blend film.</P> <P>Graphic Abstract</P><P>The addition of hole-transporting molecules to polymer/fullerene bulk heterojunction layers improved the performance of polymer solar cells. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c002771e'> </P>

Predictors of Relapse in Patients with Organizing Pneumonia

( Minjung Kim ),( Seung Ick Cha ),( Hyewon Seo ),( Kyung Min Shin ),( Jae Kwang Lim ),( Hyera Kim ),( Seung Soo Yoo ),( Jaehee Lee ),( Shin Yup Lee ),( Chang Ho Kim ),( Jae Yong Park ) 대한결핵 및 호흡기학회 2015 Tuberculosis and Respiratory Diseases Vol.78 No.3

Background: Although organizing pneumonia (OP) responds well to corticosteroid therapy, relapse is common during dose reduction or follow-up. Predictors of relapse in OP patients remain to be established. The aim of the present study was to identify factors related to relapse in OP patients. Methods: This study was retrospectively performed in a tertiary referral center. Of 66 OP patients who were improved with or without treatment, 20 (30%) experienced relapse. The clinical and radiologic parameters in the relapse patient group (n=20) were compared to that in the non-relapse group (n=46). Results: Multivariate analysis demonstrated that percent predicted forced vital capacity (FVC), PaO2/FiO2, and serum protein level were significant predictors of relapse in OP patients (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.70-0.97; p=0.018; OR, 1.02; 95% CI, 1.00-1.04; p=0.042; and OR, 0.06; 95% CI, 0.01-0.87; p=0.039, respectively). Conclusion: This study shows that FVC, PaO2/FiO2 and serum protein level at presentation can significantly predict relapse in OP patients.

영상분석기법을 활용한 도시철도 환승통로의 LOS 등급별 보행특성 분석

신민정(Minjung Shin),허진호(Jinho Hur),김희규(Heekyu Kim),문영삼(Youngsam Moon),김진호(Jinho Kim),이나현(Nahyun Lee) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.10

도시철도 이용객의 증가로 수도권 일부 정거장의 경우 일일 이용객 수가 20만명 이상이며, 특히 환승통로의 극심한 혼잡상황이 반복되고 있다. 이에 본 연구에서는 LOS등급별 밀도에 따른 속도 및 보행패턴 검증을 위해 보행특성 관찰이 가능한 모션인식 카메라를 이용한 현장실험을 수행하였다. 실험장소는 도시철도 대림역으로 역사 내 환승인원이 가장 밀집한 구간을 선정하여 평일 1일간 시간대별 밀도, 속도, 시간 및 행동패턴을 측정하였다. 도시철도 면적산정 시 평균속도는 1m/s이나 실험결과 LOS D등급은 0.8m/s, E등급은 0.58m/s로 분석되었다. 도출된 결과로부터 도시철도 이용객 LOS 수준을 효과적으로 예측 및 평가하고, 정거장의 개선 또는 신설 시 경제적, 효율적 면적 산정을 위한 기초자료로 활용하고자 한다. In the case of some stations in the metropolitan area by increasing of metro passengers, it is more than 200,000 the number of daily passengers. Especially serious congestion of transfer passage is repeated. In this study, it was conducted field experiments using the motion sensing camera capable of walking characteristics observed for the verification of the walking speed and the patterns of behavior in accordance with the LOS graded density. Experiment location is a metro Daerim Station. The transfer passage in the most crowded section was selected. Hourly the density, walking speed, time and the behavior patterns were measured for one weekday. The average speed in metro area estimates is 1m/s. The results of the experiment were analyzed to LOS D in 0.8m/s and LOS E in 0.58m/s. The LOS of metro passengers were effectively predicted and evaluated from the derived results. The results of this study utilized as a basic data to calculate an appropriate area when the improvement or construction of the station.

장애인의 치과의료 이용 접근성 비교 분석

박신후 ( Shin Hoo Park ),김호종 ( Ho Jong Kim ),정재연 ( Jae Yeon Jeong ),홍민정 ( Minjung Hong ),김나영 ( Nayoung Kim ),박종연 ( Chong Yon Park ),신의철 ( Euichul Shin ) 대한보건협회 2021 대한보건연구 Vol.47 No.1

연구목적 : 본 연구는 장애인과 비장애인의 치과의료 이용 현황을 파악 및 비교분석하고, 치과의료 이용과 관련된 특성을 보정 후 장애가 치과의료 이용 접근성에 미치는 영향을 파악하고자 하였다. 연구방법 : 2016년도 국민건강보험공단의 건강정보자료를 이용해서 장애인 251,497명, 비장애인 4,888,249명을 선별하고, 장애가 치과의료 이용 접근성에 미치는 영향을 분석하기 위해 통제변수인 성별, 연령, 의료보장유형, 소득수준, 지역, 흡연, 고위험 음주, 만성질환 여부를 통제한 상태에서 다중 로지스틱 회귀분석(multiple logistic regression)을 실시하였다. 연구결과 : 치과의료 이용률은 장애인 42.0%, 비장애인 43.2%로 장애인이 비장애인 보다 0.97배 낮게 나타났다. 그리고 통제변수를 통제한 상태에서 로지스틱 회귀분석 결과, 치과의료 이용 접근성과 관련된 특성을 통제하였을 때 장애인이 비장애인보다 치과의료 이용을 경험할 확률이 0.97배 낮은 것으로 나타났다. 결론 : 이상의 결과를 종합하여 살펴보면, 장애인은 보정 후에도 비장애인보다 치과의료 이용을 경험할 확률이 낮아 장애인의 치과의료 접근성이 낮은 것을 확인 할 수 있었다. 따라서 장애인의 치과의료 이용에 대한 접근성을 높이기 위한 정책적 방안이 필요하다. Background : The purpose of this study was to compare the current status of dental service utilization between People with Disabilities and People without Disabilities, and to investigate the effects of disability on access to dental service after adjusting the characteristics related to dental service utilization. Methods : Data used in this study from National Health Insurance Service 2016 health information data. Sample size were 251,497 People with Disabilities and 4,888,249 People without Disabilities. Analysis method in this study was multiple logistic regression analysis in which control variables were gender, age, health insurance type, income level, region, smoking, high-risk drinking and chronic disease. Results : Dental service utilization rate was 42.0% for the People with Disabilities and 43.2% for the People without Disabilities, which was 0.97 times lower than for the People without Disabilities. The result of logistic regression analysis with controlled variables indicated that the People with Disabilities was 0.97 times less likely to experience dental care than the People without Disabilities when the characteristics related to access to dental service utilization were controlled. Conclusion : In summary, People with Disabilities are less likely to experience dental service utilization than People without Disabilities, even after adjusting. Therefore, policy measures are needed to increase access to dental service utilization for the People with Disabilities.

도시철도 역사 건축계획의 동선설계 영향요인 분석

신민정(Minjung Shin),허진호(Jinho Hur),김희규(Heekyu Kim),문영삼(Youngsam Moon),김진호(Jinho Kim) 한국철도학회 2017 한국철도학회 학술발표대회논문집 Vol.2017 No.05

도시철도 이용객 증가로 이동·환승 거리 및 시간, 혼잡도, 역사이용시설 편의성 등의 개선이 필요한 상황이다. 이에 본 연구에서는 환승 편의성 및 이용객 만족도 향상을 위하여 기존 역사 유형별 이동특성을 분석하였다. 도시철도 15개 역사의 이용객 동선 및 승강편의시설에 따른 환승 특성을 분석하고, 환승계획과 동선설계에 따른 영향요인을 도출하였다. 역사 내 한정된 공간에서 승·하차, 이동, 환승, 게이트 통과 등의 활동은 이동 동선을 따라 발생하며, 특히 혼잡시간 대에는 방향별 동선의 충돌로 인해 보행자의 이동저항이 급속히 증가해 통행시간 증가, 안전사고 발생 등 도시철도 역사의 이용효율을 저해하는 요인으로 작용하므로 동선설계가 매우 중요한 것으로 분석되었다. 도출된 결과를 활용하여 역사시설 개선을 위한 설계 자료로 활용하고자 한다. The increase in the number of passengers on the urban railway requires improvements in transfer distance and time, congestion, and the convenience of the facilities. In this study, the characteristics of the existing station transfer types were analyzed to improve the transfer convenience and customer satisfaction. The transfer characteristics of the flow and elevating convenience facilities of the 15 stations were analyzed. According to the analysis result, the influential factors of the transfer planning and the design of the station were derived. The movements such as getting in and out, moving, transferring, and passing through a gate in a limited space in the station occur along the moving route. Especially, the movement resistance of the pedestrian increases rapidly due to the collision of the moving line by the direction in the congestion time zone. This is a factor that hinders the utilization efficiency of the station, such as increased travel time and safety accidents. Therefore, it is analyzed that the flow design of the station is very important. The results of this study will be used as design data for improvement of station facilities.

복합환승센터 스마트 인프라시스템 적용을 위한 국내외 기술동향 분석

신민정(Minjung Shin),허진호(Jinho Hur),김희규(Heekyu Kim) 한국철도학회 2018 한국철도학회 학술발표대회논문집 Vol.2018 No.5

Predictors of Relapse in Patients with Organizing Pneumonia

Kim, Minjung,Cha, Seung-Ick,Seo, Hyewon,Shin, Kyung-Min,Lim, Jae-Kwang,Kim, Hyera,Yoo, Seung-Soo,Lee, Jaehee,Lee, Shin-Yup,Kim, Chang-Ho,Park, Jae-Yong The Korean Academy of Tuberculosis and Respiratory 2015 Tuberculosis and Respiratory Diseases Vol.78 No.3

Background: Although organizing pneumonia (OP) responds well to corticosteroid therapy, relapse is common during dose reduction or follow-up. Predictors of relapse in OP patients remain to be established. The aim of the present study was to identify factors related to relapse in OP patients. Methods: This study was retrospectively performed in a tertiary referral center. Of 66 OP patients who were improved with or without treatment, 20 (30%) experienced relapse. The clinical and radiologic parameters in the relapse patient group (n=20) were compared to that in the non-relapse group (n=46). Results: Multivariate analysis demonstrated that percent predicted forced vital capacity (FVC), $PaO_2/FiO_2$, and serum protein level were significant predictors of relapse in OP patients (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.70-0.97; p=0.018; OR, 1.02; 95% CI, 1.00-1.04; p=0.042; and OR, 0.06; 95% CI, 0.01-0.87; p=0.039, respectively). Conclusion: This study shows that FVC, $PaO_2/FiO_2$ and serum protein level at presentation can significantly predict relapse in OP patients.