Modification of Indium Tin Oxide with Dendrimer-Encapsulated Nanoparticles To Provide Enhanced Stable Electrochemiluminescence of Ru(bpy)₃²⁺/Tripropylamine While Preserving Optical Transparency of Indium Tin Oxide for Sensitive Elec

Kim, Yeoju,Kim, Joohoon American Chemical Society 2014 ANALYTICAL CHEMISTRY - Vol.86 No.3

<P>Here, we report highly enhanced stable electrogenerated chemiluminescence (ECL) of Ru(bpy)<SUB>3</SUB><SUP>2+</SUP> (bpy = 2,2′-bipyridyl) with tripropylamine (TPrA) coreactant on indium tin oxide (ITO) electrodes modified with amine-terminated dendrimers encapsulating catalytic nanoparticles while maintaining optical transparency of ITO and feasibility of the modified ITOs to sensitive ECL-based assays. As model systems, we prepared Pt and Au dendrimer-encapsulated nanoparticles (DENs) using amine-terminated sixth-generation poly(amido amine) dendrimers and subsequently immobilized the DENs onto ITO surfaces via electrooxidative grafting of the terminal amines of dendrimers to the surfaces. The resulting DEN-modified ITOs preserved good optical transparency of ITO and exhibited highly catalyzed electrochemical oxidation of Ru(bpy)<SUB>3</SUB><SUP>2+</SUP>/TPrA, leading to significantly increased ECL emission. Especially, the Pt DEN-modified ITO electrode provides negligible transmittance drop, i.e., only ∼1.99% over the entire visible region, and exhibited not only much enhanced (i.e., ∼213-fold increase compared to ECL obtained from bare ITO) but also stable ECL emission under consecutive potential scans from 0.00 to 1.10 V for 10 cycles, which allowed ∼329 times more sensitive ECL-based analysis of nicotine using the Pt DEN-modified ITO compared with the use of bare ITO.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2014/ancham.2014.86.issue-3/ac403415m/production/images/medium/ac-2013-03415m_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac403415m'>ACS Electronic Supporting Info</A></P>

Dendrimer Encapsulated Pt Nanoparticle-Immobilized Glassy Carbon Electrode with High Electrocatalytic Redox Activity to Hydrogen Peroxide and Its Application for Biosensing

Kim, Yeoju,Ju, Heeyoung,Kim, Joohoon Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Recommended Auditory Brainstem Responses to Stimulation and Recording Parameters for Hidden Hearing Loss: A Systematic Review and Meta-Analysis

Yeoju Kim,Woojae Han 한국청각언어재활학회 2023 Audiology and Speech Research Vol.19 No.2

Although a lesion of hidden hearing loss (HHL) has focused on the sprial ganglion, stimulation and recording parameters for auditory brainstem response (ABR) are not yet specific enough to confirm its dysfunction. In the current review, we identify ABR parameters, especially Wave I, for diagnosing HHL through both a systemic review and meta-analysis of 14 articles retrieved from seven journal data bases. The most commonly used parameters were a click or 4 kHz tone burst as the stimulus at a rate of less than 11/sec at more than 80 dB intensity levels with alternating polarity through the ear canal. For quantitative results, our meta-analysis from eight articles demonstrated a significant difference in the overall effect size for amplitude between HHL patients and their counterparts with normal hearing. For the subgroup and its analysis, tone burst and high intensity level revealed significantly lower effect size in HHL patients compared to the control group, whereas the stimuli rate and electrode montage statstically were not statistical significance. Although we examined a small number of studies and their heterogenity, obtaining ABR Wave I was clinically differentiated when noise-induced HHL was considered. We thus suggest that stimulation and recording parameters should be applied to a large number of patients and thereby standardized as sensitive features for Wave I in the clinic.

Dendrimer Encapsulated Pt Nanoparticle-Immobilized Glassy Carbon Electrode with High Electrocatalytic Redox Activity to Hydrogen Peroxide and Its Application for Biosensing

Yeoju Kim,주희영,김주훈 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

청소년 사이버폭력 피해로 인한 인지변화 척도 개발

정여주(Chung, YeoJu),김한별(Kim, HanByul),김희주(Kim, HeeJu) 학습자중심교과교육학회 2017 학습자중심교과교육연구 Vol.17 No.18

The purpose of this study was to develop and validate a scale to measure cognitive change for cyberbullied youth. This study was performed to 1377 elementary, middle, and high school students from May to D ecember 2015. 53 items for preliminary survey were developed based on previous studies and FII(Focus Individual Interview), and final items were selected according to the results of exploratory factor analysis and reliability and validity analysis. As a result of exploratory factor analysis, total 25 items(assessment about the offender 6 items, internalization of damage problems 6 items, assessment about the other peoples 5 items, worry about peer relationship 5 items, thought about result of cyberbullying 3 items) were chosen. The results for main survey was that high reliability(Cronbach α = .968) was confirmed and support for the scale’s criterion validity has been demonstrated by relationship to the Cyberbullying Experience scale(r = .210~.337), Cyberbullied Adolescents Behavioral Response scale(r = .428~.637). The results of construct validation showed five-factor structure to be valid, and demonstrated correlations among the subscales (NFI = .935, TLI = .932, CFI = .945, RMSEA = .068). The scale developed in this study provide much more information about youth cognitive change by cyberbullying, moreover it will be useful when we counsel with victims of cyberbullying. 본 연구는 사이버폭력 피해를 경험한 청소년의 인지변화에 관한 척도를 개발하고 타당하기 위한 목적으로 이루어졌다. 본 연구는 2015년 5월부터 12월까지 초 중 고 등학생 1377명을 대상으로 실시되었고, FII(Focus Individual Interview)와 문헌 연구 를 바탕으로 예비조사 문항을 구성한 후, 탐색적 요인분석을 통해 본조사 문항을 추출하고 신뢰도 및 타당도 분석을 통해 최종문항을 확정하였다. 예비조사 문항 53개에 대한 탐색적 요인분석을 실시한 결과, 가해자에 대한 부정적 개념화 6문항, 피해 문제의 내면화 6문항, 세상 사람에 대한 평가 5문항, 친구관계에 대한 걱정 5문항, 결과에 대한 생각 3문항 총 25문항이 최종적으로 선정되었다. 본조사 결과를 바탕으로 분석하였을 때, 전체 신뢰도는 Cronbach’s α 값이 .968로 나타났고, 준거타당도 분석을 위해 함께 실시한 사이버폭력 경험 피해 척도, 사이버폭력 피해 행동반응 척도와 의 상관 점수가 각각 .210~.337, .428~.637로 측정문항이 타당함을 확인할 수 있었다. 구인타당도 분석을 위해 확인적 요인분석을 실시한 결과, NFI, TLI, CFI, RMSEA의 값이 각각 .935, .932, .945, .068으로 측정모형이 매우 적합하였다. 본 연구 에서 개발된 척도는 사이버폭력 피해를 경험한 청소년들의 인지 변화를 구체적으로 살펴보고, 상담적 접근을 취할 수 있는 근거자료를 마련해준다는 점에서 의의를 가 진다.

인 고도처리를 위한 일체형 침전부상공정(SeDAF)의 최적 응집제 주입조건 결정

장여주 ( Yeoju Jang ),정진홍 ( Jinhong Jung ),장향연 ( Hyangyoun Chang ),박나리 ( Nari Park ),임현만 ( Hyunman Lim ),김원재 ( Weonjae Kim ) 한국수처리학회(구 한국수처리기술연구회) 2020 한국수처리학회지 Vol.28 No.4

Algal blooms are caused by eutrophication, increased water temperature, and reduced water flow rate, and produce taste·odor compounds and health problems associated with cyanobacterial toxins. To prevent eutrophication and algal blooms, the Ministry of Environment (MOE) in Korea reinforced effluent standards for wastewater treatment facilities and, as a result, spurred the implementation of various advanced wastewater treatment processes to achieve compliance. Current tertiary wastewater treatment techniques are conventionally single processes, such as sedimentation or flotation, and have high operational costs and produce undesirable sludge problems due to excessive coagulant injection. Here, we develop a sedimentation and dissolved air flotation (SeDAF) process that integrates sedimentation and flotation for applications in advanced wastewater treatment. Jar-tests were used to evaluate water quality and treatment efficiency for sedimentation and sedimentation·flotation processes, respectively. Equations that estimate the optimal coagulant dosage are proposed to enhance the field applicability of the SeDAF process. Two types of jar-tests, both sedimentation and sedimentation·flotation, and multiple regression analyses are comprehensively examined to identify appropriate operation conditions for the SeDAF process considering fluctuations in field conditions such as T-P concentration, PO4-P / T-P ratio, turbidity, and flow rate etc.

천연조류제거제를 활용한 응집·부상 공정과 기존 응집공정 비교

장여주 ( Yeoju Jang ),정진홍 ( Jinhong Jung ),임현만 ( Hyunman Lim ),장향연 ( Hyangyoun Chang ),김원재 ( Weonjae Kim ) 한국물환경학회 2017 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2017 No.-

하수 고도처리를 위한 일체형 침전부상공정의 적용성

장여주 ( Yeoju Jang ),정진홍 ( Jinhong Jung ),임현만 ( Hyunman Lim ),김원재 ( Weonjae Kim ) 한국물환경학회(구 한국수질보전학회) 2019 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2019 No.-

인 고도처리를 위한 일체형 침전부상공정(SeDAF)의 슬러지 발생특성

장여주(Yeoju Jang),정진홍(Jinhong Jung),장향연(Hyangyoun Chang),박나리(Nari Park),미라툴 매크피로(Miratul Maghfiroh),김원재(Weonjae Kim) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.11

목적: 공공수역의 부영양화를 방지하기 위하여 환경부에서는 공공하수처리시설의 방류수 수질기준을 강화한 결과, 국내 하수처리시설에는 다양한 인 고도처리공정이 도입되었다. 기존의 인 고도처리시스템은 일반적으로 과도한 약품비 및 슬러지 발생 등의 문제를 안고 있기 때문에 새로운 공정의 개발이 필수적이다. 방법: 본 연구에서는 침전과 부상분리를 통합한 일체형 침전부상공정(SeDAF)을 개발하고, 해당 공정의 운전조건을 최적화하기 위하여 여러 모의실험을 수행하였다. 수정된 Jar-test 기법을 사용하여 SeDAF 공정에서의 수질 변화 및 슬러지 발생특성을 집중적으로 분석하였다. 결과 및 토의 : 전 수질항목에서 침전공정 대비 침전부상공정의 제거효율이 우수하고 안정적인 것으로 나타났다. SeDAF 공정에서는 응집제 주입농도의 증가에 따라 슬러지 발생량이 4 ㎎・L<SUP>-1</SUP> as SS / ㎎・L<SUP>-1</SUP> as Al₂O₃씩 비례하여 증가하는 것으로 나타났다. 최적처리조건(최적 응집제 주입조건)에서 부상슬러지 및 침전슬러지 내 고형물질(suspended solids, SS) 및 총인(total phosphorus, T-P)의 부하비율(ratio)과 총 슬러지 대비 부상슬러지 내 SS 및 T-P의 부하분율(fraction)은 일정한 범위로 수렴하는 것으로 나타났다. 결론: 슬러지 내 부하비율(ratio) 및 부하분율(fraction) 인자를 모니터링함으로써 일체형 침전부상공정(SeDAF) 운전조건의 적정성을 판단할 수 있는 것으로 나타났으며, 응집제 주입농도의 저감이 슬러지 발생량의 감소로 직결됨을 확인하였다. Objectives : In order to prevent eutrophication and algal blooms, Ministry of Environment in Korea reinforced the effluent standards of wastewater treatment facilities. As a result, many advanced wastewater treatment processes have been implemented nationwide. Current conventional treatment systems have usually been facing high operational costs and large sludge production problems. Therefore, it is essential to develop more economic and efficient process to cope with these issues. Methods : The sedimentation and dissolved air flotation (SeDAF) process has been developed, that integrates sedimentation and dissolved air flotation. Several simulation experiments were carried out to verify and optimize the operation conditions of the SeDAF process. Removal efficiencies of each water quality item and sludge mass balance were analyzed intensively in the SeDAF process using the modified jar-test. Results and Discussion : Removal efficiencies of the SeDAF process were higher and more stable than those of sedimentation process. Several ‘sludge production / coagulant dosage’ ratios were analyzed and the representative value of 4 ㎎・L<SUP>-1</SUP> as SS / ㎎・L<SUP>-1</SUP> as Al₂O₃ was obtained in the SeDAF process. Fractions of suspended solids (SS) and total phosphorus (T-P) in sludge were measured; the ratios of flotation sludge to sedimentation sludge and fractions of flotation sludge in total sludge had their typical convergence ranges for the conditions of optimal coagulant dosage. Conclusions : The ratios or fractions of SS and T-P in sludge could be applied as the evaluation indicators of the SeDAF process. The reduction of coagulant dosage could be corresponded directly to the reduction of sludge production.

인 고도처리를 위한 침전부상공정(SeDAF)에서 Al/P비(aluminium/phosphorus ratio)의 적용성 검토

장여주(Yeoju Jang),정진홍(Jinhong Jung),안광호(Kwangho Ahn),임현만(Hyunman Lim),김원재(Weonjae Kim) 대한환경공학회 2020 대한환경공학회지 Vol.42 No.11

목적: 부영양화 및 조류 발생을 방지하기 위하여 환경부에서는 하수처리시설의 방류수 수질기준을 강화해 왔으며, 지난 20년간 전국적으로 다양한 인 고도처리시설이 도입되었다. 기존의 인 고도처리공정을 효율적으로 대체할 수 있는 일체형 침전부상공정(sedimentation・dissolved air flotation process; SeDAF process)이 이전 연구에서 개발된 바 있다. 본 연구에서는 SeDAF 공정의 운영조건을 도출하기 위해 다양한 운전인자를 검토하였고, 특히, 알루미늄/인(Al/P)비 및 알루미늄/탁도(Al/T)비의 적용성을 평가하였다. 방법: SeDAF 공정의 적정 운전조건을 도출하기 위하여 여러 Lab-scale 모의실험을 수행하였다. 각 운전조건에 대해 Al/P (Al/T-P)비, Al/PO₄<SUP>3-</SUP>-P비 및 Al/T (Al/Turbidity)비를 분석하고 비교・검토하였다. 결과 및 토의 : Al/P비가 안정성 및 운전용이성 측면에서 가장 우수하였으며, SeDAF 공정에서는 기존 문헌에서 보고된 Al/P비의 범위보다 낮은 조건에서도 양호한 처리효율을 달성할 수 있는 것으로 나타났다. 결론: SeDAF 공정의 운전 시 Al/P비를 활용하여 응집제 주입농도를 결정함으로써, 응집제 주입농도 저감 및 슬러지 발생량 감소 등 여러 이점을 얻을 수 있을 것으로 기대한다. Objectives : To prevent eutrophication and algal blooms, Ministry of Environment in Korea has reinforced the effluent standards of wastewater treatment facilities. In the last 20 years, various advanced wastewater treatment processes have been introduced nationwide. The sedimentation・dissolved air flotation (SeDAF) process has been developed for efficient enhanced phosphorus removal in the previous researches. In the study, several factors were reviewed to examine the operation characteristics of the SeDAF process. In particular, the applicability of aluminium/phosphorus (Al/P) and aluminium/turbidity (Al/T) ratios were investigated intensively. Methods : To derive the appropriate operating conditions for the SeDAF process, several sets of lab-scale tests were carried out. For each operating condition, Al/P (Al/T-P), Al/PO₄<SUP>3-</SUP>-P, and Al/T (Al/Turbidity) ratios were analyzed, compared and reviewed respectively. Results and Discussion : Al/P ratio was revealed as the most prominent factor in terms of stability and feasibility of operation, and Al/P values of the SeDAF process could achieve lower values than those of other processes in the previous researches. Conclusions : It could be expected that the coagulant dosage decision using Al/P ratio has many advantages to reduce coagulant dosage and to decrease the amount of sludge production in the SeDAF process.