Fluorination effect on desalination behavior of activated carbons as electrode materials

조한주,김경훈,이영석 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1

Activated carbons (ACs) are fluorinated and prepared to electrode to identify the desalination behavior of fluorinated activated carbon (F-AC) according to the sign of F-AC electrode for capacitive deionization (CDI). Changes in specific surface area and surface functional groups of ACs after fluorination are confirmed using ASAP 2020 and X-ray photoelectron spectroscopy (XPS), respectively. Specific capacitance and CDI performance are evaluated by cyclic voltammetry (CV) and CDI experiments, respectively. In CDI experiments, when the CDI cell assembled by untreated activated carbon (R-AC) electrode as anode and F-AC electrode as cathode, salt adsorption capacity and charge efficiency are increased from 10.3 mg/g and 0.54 to 12.6 mg/g and 0.78, respectively, compared with the CDI cell symmetrically assembled by R-AC electrodes. These results are attributed that fluorination assign the cation selectivity to nature of AC surface, which reduce co-ion expulsion effect.

A Case of Susac Syndrome

조한주,김철구,조성원,김종우 대한안과학회 2013 Korean Journal of Ophthalmology Vol.27 No.5

The purpose of this article is to report on the first known Korean case of Susac syndrome. An 18-yearold female came to our clinic reporting blurred vision of the left eye for 2 days. She also complained of decreased hearing with tinnitus of the right ear and mild headache. She was previously healthy and had no remarkable medical history. Best-corrected visual acuity was 20 / 50 in the left eye and 20 / 20in the right eye. An axiomatic triad of ocular, cochlear, and neurologic involvement was observed in the patient. Fluorescein angiography showed branched retinal arterial occlusions in the left eye. A sudden right sensorineural hearing loss was observed on audimetry. Magnetic resonance images showed a hyperintense lesion in the white matter around the corpus callosum. The patient was treated with high doses of systemic corticosteroids, and no neuropsychological sequelae were observed. This is the first case report of Susac syndrome in Korea. In cases of retinal arterial occlusion with hearing loss or neuropsychological symptoms, Susac syndrome should be suspected.

Short-term Effectiveness of Intravitreal Bevacizumab vs. Ranibizumab Injections for Patients with Polypoidal Choroidal Vasculopathy

조한주,백지선,이동원,김철구,김종우 대한안과학회 2012 Korean Journal of Ophthalmology Vol.26 No.3

Purpose: To compare the effectiveness of intravitreal injections of bevacizumab and ranibizumab in patients with treatment-naive polypoidal choroidal vasculopathy (PCV). Methods: Records from 106 consecutive patients who received intraviteral bevacizumab (n = 58, 1.25 mg) or ranibizumab (n = 52, 0.5 mg) for treatment of PCV were retrospectively reviewed. After three initial monthly loading injections, injection was performed as needed. The main outcome measures included best-corrected visual acuity (BCVA), foveal central thickness (FCT) as assessed by spectral domain optical coherence tomography,and the changes in polypoidal lesions based on an indocyanine green angiography. Results: The average number of injections was 3.31 ± 1.25 in the bevacizumab group and 3.44 ± 0.92 in the ranibizumab group. Mean logarithm of the minimum angle of resolution of BCVA from baseline to 6 months after injection improved by 0.17 in the bevacizumab group (p = 0.03) and by 0.19 in the ranibizumab group (p = 0.01). Average FCT decreased from 322 ± 62.48 μm to 274 ± 40.77 μm in the bevacizumab group (p = 0.02)and from 338 ± 50.79 μm to 286 ± 36.93 μm in the ranibizumab group (p = 0.02). Polyp regression rate was 20.7% (12 of 58 eyes) in the bevacizumab group and 21.2% (11 of 52 eyes) in the ranibizumab group. There was no statistically significant difference between groups in BCVA improvement achieved, FCT improvement achieved, and polyp regression rate between groups. Conclusions: Intravitreal injections of bevacizumab and ranibizumab have similar effects in stabilizing of visual acuity, macular edema, and regression of polypoidal complex in PCV eyes over the short term.

2P-714 Enhancement of desalination performance via fluorination on activated carbons used in asymmetric capacitive deionization

조한주,김경훈,정민정,이경민,이상민,이영석 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Fluorination is one of the effective surface treatment methods on carbon materials because of high electronegativity of fluorine atoms. In this study, activated carbons (ACs) were fluorinated and used in electrode materials for asymmetric capacitive deionization (CDI). Changes in textural properties and surface chemical properties of ACs after the fluorination were measured by N2 adsorption/desorption analysis and X-ray photoelectron spectroscopy (XPS), respectively. In desalination tests, asymmetric CDI cells assembled with an untreated AC electrode (ACR) as the counter electrode and a fluorinated AC electrode (ACF2) as the cathode (RF-) or anode (RF+). For RF-, the salt adsorption capacity and charge efficiency were increased from 10.2 mg/g and 0.58 to 12.6 mg/g and 0.76, respectively, compared with the CDI cell assembled with identical ACR electrodes. It is attributed that ACF has a cation attractive effect originating from the high electronegative fluorine functional groups.

촉지성이 강화된 미디어가 사용자 공감에 미치는 영향 : 3D디스플레이 사용자 경험을 중심으로

조한주,배상원,이혜인,박준아,김진우 한국경영정보학회 2010 한국경영정보학회 학술대회논문집 Vol.2010 No.1

최근 3DTV, HDTV와 같이 촉지성이 강화된 미디어가 빠른 속도로 성장하고 있고, 그 적용 범위 역시 모바일, 컴퓨터 등으로 확대되고 있는 추세이다. 기존의 3D디스플레이 관련 연구들이 대부분 개인의 몰입감 혹은 업무 수행능력 향상에 대한 연구들이 대부분이었다. 3D디스플레이의 초현실적이고, 풍부한 표현을 통해 사용자에게 제공해줄 수 있는 감성적인 경험에 대한 연구는 많이 부족한 실정이다. 본 연구는 3D디스플레이를 통한 지각된 통제성과 지각된 수용성이 ‘공감’이라는 경험에 미치는 영향을 알아보고자 한다. 이를 위해 본 연구에서는 3D디스플레이를 통해 게임을 한 뒤 설문을 진행하는 실증적인 연구를 진행하였다. 연구 결과 지각된 통제성과 지각된 수용성이 사용자들이 지각하는 사실감(극사실주의, 마술적 사실주의)에 영향을 미치고, 궁극적으로 공감에 긍정적인 영향을 미친다는 것을 확인하였다.

패널식 토론을 활용한 역사과 학습지도 모형 개발 연구

조한주 이화여자대학교 교육대학원 2004 이화교육논총 Vol.14 No.-

This study presents a panel-debate model of history education that stimulates students' interest in history, improves their ability to perceive history and critically develops their ability for self-study. This study verifies that the suggested panel-debate model can be practied very easily and we can achieve the education objective very effectively using the model in history classes. Results of tests and questionnaires strongly wupport this argument. The empirical framework for measuring the effect of discussions on students' performance is designed as follows. The 366 students of 11 classes (3rd graders) of J middles school in Seoul region are studied. They are divided into two groups: one experimental class used panel discussions when each chapter of history text was finished and summarized. Panel debate is organized with two groups that adopt contrasting views on the same issus for example, one proup represents advocates of the open-door policy of the Chosun dynasty in the 19th century with the other representing the closed-door policy and the two groups debate with each other on the pros and cons of their respective policies. Three topics of Chapter 4 of the textbook of Korean History are tested in this study to estimate the effect of the debated model on student performance (enhancement in historical thinking). The validity and reasonability of all the problems are evaluatied by questionnaires answered bjy history teachers in the Seoul metorpolitan region. The basic results are summarized as follows. First, student ability in historical thinking clearly impjroved through the introduction of debate into classrooms. Second, discussion leads students to have stronger motivation for studies than before and to regard historical knowledge as useful and applicable. Third, students participating in panel debate class records better performance than before and than those who do not. Fourth, self-studying ability is clearly increased. This is mainly due to excellent motivation for learning and thorough reviews on various aspects of historical fact. Fifth, in a questionnaire, history teachers evaluated the panel-debate model as being practiced easily in classrooms to improve student scholatic achievement, historical thinking and self-studying ability. Therefore, we can conclude that the debate model is highly manageable and develops historical and high-level thinking to enhance the ability for self-study.

Preparation and characteristics of mesophase pitches prepared from chemically modified pitch with AlCl3

조한주,김도영,민병철,이영석 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

Mesophase pitches consist of molecules including high aromaticity and orientation. So, mesophase pitches based carbon materials have high thermal, electrical properties. Therefore it is important to understand the changes of chemical characteristics of the molecules during preparation of mesophase pitches from isotropic pitches in order to manufacture the high performance carbon materials. In this study, we prepared isotropic pitches from pyrolysis fuel oil with AlCl3 through catalytic modification as precursors of mesophase pitches. And then, prepared pitches were transformed the mesophase pitches through high heat treatment according to various reaction time. Elementary compositions of the mesophase pitches were confirmed by elemental analysis(EA). In addition, their aromaticities were calculated by combination of elemental analysis and fourier transform infrared spectroscopy(FT-IR) results. Crystallinities and molecular structures of the mesophase pitches were examined using X-ray diffraction(XRD) and solid state carbon-13 nuclear magnetic resonance(13C NMR) respectively.

성인에서 발생하는 급성 내사시의 임상적 특징

조한주,라상훈,Han-Joo Cho,Sang-Hoon Rah 대한안과학회 2005 대한안과학회지 Vol.46 No.11

Purpose: To identify the characteristics of adult patients who develop acute concomitant esotropia during adulthood. Methods: Using a retrospective noncomparative method, this study evaluated the medical charts of 10 adults who were diagnosed with acute onset esotropia between January 2003 and May 2005. All patients presented the symptoms of estotropia when they were older than age 18. All patients in the study group had no previous ocular history, no cause of interruption of fusion, no history of systemic disease or head trauma, and no abnormal findings on neurologic examination. Results: The average follow-up period was 10.8 months (range, 5~17 months). The mean age was 44.7 years (range, 18~62 years). The average refractive error was -1.43 diopter (range, -5.50~+0.50 diopter). An operation was performed in one case. The prism diopter decreased according to follow-up in other patients. Conclusions: There are characteristics of acute onset esotropia of adulthood that differentiate it from existing esotropia. Almost all patients were myopic, showed nearly the same prism diopter between near and far vision, and deviation improved with follow-up.

2P-790 Fluorination effect of activated carbons as electrode materials on asymmetric capacitive deionization

조한주,김경훈,정민정,이경민,이상민,이영석 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.0

석유계 잔사유로부터 저온 2단 열처리를 이용한 메조페이스 핏치 제조 및 특성

조한주,정민정,이형익,이영석 한국수소및신에너지학회 2016 한국수소 및 신에너지학회논문집 Vol.27 No.4

To prepare mesophase pitches through low energy process, pyrolysis fuel oil with AlCl3 has been modified using two-step heat treatment which is heat-treated at 330°C for 3~5 h after pre-treatment at 250°C. The result of polarized optical microscope observation, mesophase is not observed in pitches carried out only pre-heat treatment. While mesophase content is significantly increased from 9% to 100% according to increasing secondary heat treatment time from 3 h to 5 h. Synthesizing of the mesophase pitch at low temperature of 330°C is attributed to decrease of viscosity of the pitches carried out first heat treatment with AlCl3. The result of Fouriertransform infrared spectroscopic analysis, it is expected that aromatization of aliphatic compounds is dominant at early secondary heat treatment, on the other hand, polycondensation reaction becomes dominant as secondary heat treatment time increases. Aromaticity and stacking height of the pitches secondary heat treated for 5 hours are more increased about 25% and 107%, respectively, than that of pitches carried out only first heat treatment.