Denitrifying Woodchip Bioreactors: A Microbial Solution for Nitrate in Agricultural Wastewater—A Review

Lee Sua,Cho Min,Sadowsky Michael J.,Jang Jeonghwan 한국미생물학회 2023 The journal of microbiology Vol.61 No.9

Nitrate ( NO3 −) is highly water-soluble and considered to be the main nitrogen pollutants leached from agricultural soils. Its presence in aquatic ecosystems is reported to cause various environmental and public health problems. Bioreactors containing microbes capable of transforming NO3 − have been proposed as a means to remediate contaminated waters. Woodchip bioreactors (WBRs) are continuous flow, reactor systems located below or above ground. Below ground systems are comprised of a trench filled with woodchips, or other support matrices. The nitrate present in agricultural drainage wastewater passing through the bioreactor is converted to harmless dinitrogen gas ( N2) via the action of several bacteria species. The WBR has been suggested as one of the most cost-effective NO3 −-removing strategy among several edge-of-field practices, and has been shown to successfully remove NO3 − in several field studies. NO3 − removal in the WBR primarily occurs via the activity of denitrifying microorganisms via enzymatic reactions sequentially reducing NO3 − to N2. While previous woodchip bioreactor studies have focused extensively on its engineering and hydrological aspects, relatively fewer studies have dealt with the microorganisms playing key roles in the technology. This review discusses NO3 − pollution cases originating from intensive farming practices and N-cycling microbial metabolisms which is one biological solution to remove NO3 − from agricultural wastewater. Moreover, here we review the current knowledge on the physicochemical and operational factors affecting microbial metabolisms resulting in removal of NO3 − in WBR, and perspectives to enhance WBR performance in the future.

A case report of thrombotic thrombocytopenic purpura-like syndrome after Coronavirus disease 2019 vaccination

Sua Noh,Sang A Kim,Ji Yun Lee,Jeong Ok Lee,Soo Mee Bang 대한혈액학회 2023 Blood Research Vol.58 No.2

.

Single Microcystis Detection Through Electrochemical Collision Events on Ultramicroelectrodes

Lee Jeeho,Lee Jungeun,Song Sua,Kim Byung‐Kwon 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.5

This study introduces the electrochemical detection of a single microcystis on an Au ultramicroelectrode based on single-entity electrochemistry. The electrochemical collisions occur when the microcystis is adsorbed on the electrode surface. This hinders the oxidation of the electroactive redox species in the solution, thus making the current decrease like a staircase. In this experiment, the current decrease caused by the collision which requires an appropriate concentration of the redox species and initial potential, providing information on migration effect by zeta-potential, and collision frequency. Comparison of the simulation results of the finite element method and the experimental results suggested that the staircase current decrease caused by the microcystis can occur due to collision not only on the electrode surface but also on the surrounding regions of the electrode surface (i.e., the active area). These results suggest various applications of the single-entity cell detection using the electrochemical method for real-time analysis.

“Like fine wine!”: Senior models5 perspectives on serious leisure and successful aging

Sanghee Lee,Jaeyoon Bae,Sua Im,Sunwoo Lee,Jinmoo Heo 한국서비스디자인학회 2023 한국서비스디자인학회 학술대회자료집 Vol.2023 No.1

Literature has revealed the positive impact of serious leisure among older adults. As serious leisure involves productive engagement and commitment, performing as a senior model reflects serious leisure participation of older adults, which might ojfer a new insight in promoting healthy lifestyles. While many studies have been conducted in the context of leisure behavior of older adults, a study is yet to explore the behavior of senior models. This study aimed to contribute to the theoretical knowledge regarding older adults in serious leisure settings and understand the experience of senior models. We conducted a series of face-to-face interviews with 31 participants. Interview questions focused on the participants perception as senior models and the meaning of being senior models. The ages of the participants ranged from 54 to 85 次(Mean age = 66.9). The constant comparison method was applied to continuously compare the views and experiences of the participants. Two central themes that shaped the participants ’ senior modeling experiences were identified: (1) the benefits of senior modeling and (2) the costs of senior modeling. Under each theme, several sub­ categories were identified: confidence, stylish and ageless, friendships, painful training and investing efforts, barriers associated with aging, and structural constraints. The findings obtained in this study highlight the important link between serious leisure and successful aging. Considering the benefits identified by the study participants, it is suggested that engaging in senior modeling positively affects older adults ’ quality of life.

Rhabdomyolysis-induced acute kidney injury requiring hemodialysis in a patient on long-term, moderateintensity rosuvastatin: a case report and literature review

Soyoung Lee,Suyeon Kim,Jongho Shin,Kyeong Min Kim,Sua Lee 조선대학교 의학연구원 2024 Medical Bilogical Science and Engineering Vol.7 No.1

Thermal properties in strong hydrogen bonding systems composed of poly(vinyl alcohol), polyethyleneimine, and graphene oxide

Choi, Sua,Hwang, Duck Kun,Lee, Heon Sang 한국탄소학회 2014 Carbon Letters Vol.15 No.4

Blends of poly(vinyl alcohol) (PVA), polyethyleneimine (PEI), and graphene oxide (GO) were prepared by solution casting method. Calorimetric thermal properties of the blends were investigated. The Tgs of PVA/PEI blends were higher than the Tgs of either of the component polymers at low concentrations of PEI. These abnormal increases of Tgs may be due to the negative entropy of mixing which is associated with strong hydrogen bonding between PVA and PEI. The degree of depression of T0ms was not reduced by the negative entropy of mixing, since strong hydrogen bonding also causes an increase in the magnitude of negative χ between PVA and PEI. The Tg of PVA was increased significantly by adding 0.7 wt.% GO into PVA. The magnitude of negative χ was increased by adding GO into the blends of PVA and PEI.

디지털 트윈을 이용한 식품제조공정 생산시스템 관리 감독에 관한 연구

이수아(Sua Lee),조연호(Yeonho Jo),최강인(Kangin Choi),임광진(Kwangjin Lim),김병준(Byoungjun Kim),정성환(Sunghwan Jeong) 한국정보기술학회 2023 Proceedings of KIIT Conference Vol.2023 No.6

골조직 재생을 위한 3차원 PCL/HA 인공지지체 개발

이수희(Lee SuHee),박수아(Park SuA),이준희(Lee Jun-Hee),김효주(Kim HyoJoo),김완두(Kim Wan Doo) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

Recently, three-dimensional (3D) scaffold of tissue engineering was developed by rapid prototyping (RP) technology. 3-D scaffold of RP technology provide interconnective structure for cell growth and tissue regeneration. Also, it can control the pore size and porosity using the 3D-plotting system. In this research, we fabricated hybrid scaffold of polycaprolactone PCL) and hydroxyapatite (HA) for bone tissue engineering. We used scanning electron microscopy (SEM) to observe the surface of the scaffold. To characterize the scaffold, mechanical property and cell proliferation was measured.

인공지능ㆍ빅데이터 기반 독립형 소프트웨어 의료기기 분석

이사영(Lee Sayoung),최훈(Choi Hun),김지현(Kim Jihyun),문수아(Moon Sua),이제민(Lee Jemin),유지인(Yu Jiin),정지원(Jung Ji-won) 한국콘텐츠학회 2023 한국콘텐츠학회 종합학술대회 논문집 Vol.2023 No.5

예술적 상황과 기술적 상황이 고등학생들의 물리 문제해결에 미치는 효과

이수아 ( Sua Lee ),박윤배 ( Yunebae Park ) 한국과학교육학회 2015 한국과학교육학회지 Vol.35 No.6

본 연구는 창의적이고 통합적인 사고의 활성화를 위하여 과학 문항에 예술적 요소와 기술적 요소를 도입함에 따른 효과를 알아보기 위한것이다. 평가 문항은 수능에 예술적 요소와 기술적 요소를 도입한 4개의 문항(STA)과 기술적 상황에 예술적 요소를 도입한 문항(TA)으로이루어져 있다. 특히, TA는 3개의 문항(과학 및 일상생활과 관련된문항, 창의적 설계)으로 이루어져 있다. 대구시 소재 고등학교 3학년학생 60명(남:39명, 여:21명)을 대상으로 STA에 대한 문제해결 과정을 살펴보았으며 상세한 분석을 위해 이 학생들 중 4명을 추출하여회상면접법을 이용하여 면담도 실시하였다. 또한, STA에 대한 분석결과를 기반으로 TA를 제작하여 위의 학생 4명을 대상으로 문제해결과정을 살펴보았으며 위와 마찬가지로 면담도 실시하였다. 연구 결과는 다음과 같다. 첫째, 학생들은 과학적 상황을 예술적 상황과 기술적상황보다 많이 선택하였으며 그 이유는 빠른 시간 내에 문제를 해결하기 위해 문제의 길이가 짧은 상황을 선호하기 때문인 것으로 나타났다. 둘째, STA의 예술적 상황과 기술적 상황을 과학적 상황보다 흥미롭지만 어렵게 느끼는 것으로 나타났으며 TA의 예술적 요소를 도입한 기술적 상황도 과학적 상황보다 흥미롭게 느끼는 것으로 나타났다. 셋째, 학생들은 STA에서 주어진 상황에 관계없이 문제해결에 필요한 핵심적 과학지식을 사용하여 비교적 간략하게 문제를 해결하는 경향이 있는 것으로 나타났다. 이는 학생들의 문제해결 과정이 반복학습에 의해정형화되었을 가능성이 있음을 의미한다고 볼 수 있다. STA의 모든상황에서 논리적 사고와 정교성은 나타났으나 독창성은 두드러지지않았고 통합적 사고는 나타나지 않았다. 넷째, TA의 과학과 관련된문항에서는 위와 유사한 결과가 나타났으나 일상생활과 관련된 문항의 경우 학생들은 일상생활을 기반으로 서술하였으며 독창성이 나타났으며 특히, 창의적 설계에서는 학생들의 독창적인 아이디어와 통합적 사고가 나타났다. This study examines the effects of the introduction of artistic and technological factors on science problems for the activation of creative and integrated thinking. We developed problems consisting of STA(problems that introduced technological and artistic factors on the College Scholastic Ability Test) and TA(problems that introduced artistic factors in a technological context). Subjects of the study included 60 high school senior students in Daegu. Their problem solving processes for STA were examined. Four students were interviewed using the retrospective interview method. Also, after finishing TA, the problem solving processes of four students were examined. The results of the study are as follows. First, students selected scientific context more than artistic and technological contexts. It was found that students preferred short length problem in order to solve problems in a short time. Second, students were more interested in artistic and technological contexts of STA than scientific context, but felt that they were more difficult. Moreover, students were more interested about the context of TA than scientific context. Third, irrespective of the given contexts in STA, students have a tendency to solve problems through relatively brief ways by using core scientific knowledge. This can seem to mean that there is a possibility to stereotype the problem solving process through repeated learning. Logical thinking and elaboration were observed, but creativity was not conspicuous. In addition, integrated thinking was not observed in all contexts of STA. Fourth, science related problems of TA showed similar results. However, in problems related to everyday life, students made original descriptions that they based on their daily lives. Particularly, in creative design, original ideas and integrated thinking were observed.