Conducting polymer-graphene composite as electrode material for supercapacitor

조우근,박수영 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

An electrode material for a supercapacitor has been developed based on a graphene(GP) and conductiong polymer nanocomposite. Characterizations of the synthesized composites are performed by fourier transform infrared(FT-IR) spectroscopy, Field emission scanning electron microscope(FE-SEM). Electrical properties of composite are performed by Cyclic voltammetry(CV) and Galvanostatic Charge-Discharge curves. The composites showed improvements in electrical conductivity and excellent electrochemical reversibility.

Preparation and charaterization of graphene/polypropylene nanocomposite

조우근,우재훈,박수영 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Polymeric nanocomposites have been extensively studied for their enormous potential applications in industrial fields. Most of the previous research materials which were used as the fillers in polymer nanocomposites include glass fiber, clay, carbon nanotubes, etc. They each possess their own outstanding properties which are very applicable in specific fields. Recently, however, graphene, a two-dimensional new allotrope of carbon, has attracted considerable interest because of its remarkable mechanical, electrical, thermal and optical properties. However, in many cases, graphene is not compatible with polymers. Functionalization of graphene is a way for improvement of the compatibility with polymers. The investigations focusing on the reinforcement of non-polar polymers by graphene however are very limited. This might be because creating the covalent bonds between graphene and non-polar polymers were difficult and aggregation between graphene sheets in the polymer matrix when electrostatic or steric protections on the graphene sheet were not applied. In this paper, we are reporting a method for grafting polypropylene (PP) on graphene to use graphene as a well-dispersible filler for compounding with virgin PP. The morphology, thermal stability, crystallization behavior and mechanical properties of the compounded nanocomposites were examined and compared with those of virgin PP.

Liquid-crystal based biosensor for urea detection

조우근,칸마슈크,무니르순다스,박수영 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

A transmission electron microscopy (TEM) grid filled with 4-cyano-4’-pentylbiphenyl (5CB) on an octadecyltrichloro silane-coated glass substrate was coated with a monolayer of poly(acrylicacid-b-4-cyanobiphenyl-4-oxyundecylacrylate) (PAA-b-LCP) and immobilizing urease covalently to the PAA chains for urea detection at the 5CB/aqueous interface. Urea was detected from the planar to homeotropic (P-H) orientational transition of 5CB using a polarized optical microscope. This TEM grid sensor with the maximum immobilization density of urease 0.17 molecules/nm2 enabled the detection of urea at concentrations as low as 5 mM in a response time of 250 s. This TEM grid sensor could detect urea in the blood without any inference from hemoglobin and ascorbic acid and allows easy naked eye detection, and might be useful for practical usage of urea detection.

한의 진단 지원 시스템의 시험 수행 및 평가

조우근,김명호,이상아,장명웅,최동준,Cho, Woo-keun,Kim, Myung-ho,Lee, Sang-ah,Jang, Myung-woong,Choi, Dong-jun 대한중풍순환신경학회 2012 대한중풍.순환신경학회지 Vol.13 No.1

Object : Traditional Korean Medicine Diagnostic Support System(TKMDSS) is the diagnostic prescribing system based on ontology developed by Korea Institute of Oriental Medicine. We monitored and assessed its usefulness and searched for improvements. Methods : We collected 10 cases of stroke inpatients of Dongguk University Ilsan Oriental Hospital. They were diagnosed by primary care physician and another researcher who monitored using "TKMDSS" respectively. We compared the process and results of two diagnosis. Results : The diagnostic concordance rate between primary care physician and researcher were pretty high. Most of the problems were caused by expressions on symptoms inappropriate use of terminology. The severity of symptoms and vague symptoms which is hard to be diagnosed should be reflected and measured in this system. Conclusions : The problems were about terminology and definition. The terminology should be defined accurately and in-depth detail so that anyone can get the right information. If the problems were modified, "TKMMSS" could be utilized as supportive measures for oriental medicine doctors and students.

적응잡음제거를 위한 FDAF와 MDF 알고리즘의 실시간 구현

조우근,정원용,Joh Woo-Guen,Chong Won-Yong 한국융합신호처리학회 2000 융합신호처리학회 논문지 (JISPS) Vol.1 No.1

Recently, the technologies of adaptive noise cancellation(ANC) are developed fast and widely due to the highly sophisticated digital signal processing algorithms and the high-speed communication networks and devices. But, thousand numbers of the adaptive filter taps are required to obtain the satisfying results in the fields of the adaptive noise cancellation and echo cancellation. In the paper, performance comparisons based on the real-time processing between frequency domain adaptive filter(FDAF) and multi-delay frequency domain adaptive filter(MDF) are carried. Those algorithms provide us with the reductions of the computational burdens and the increase of the convergence rate for the lengthy Fill adaptive filters. The time delay due to the long taps of FDAF can be reduced by adopting the MDF algorithms. The conventional ANC and cross talks ANC using FDAF are implemented on the dSP ACE 1103 real-time signal processing board.

Polypyrrole Nanocomposite with Water-Dispersible Graphene

조우근,Mashooq Khan,Loon-Seng Tan,정호신,이신희,박수영 한국고분자학회 2017 Macromolecular Research Vol.25 No.4

Scalable water-dispersible graphene (eGPNc) powders were prepared with consecutive chlorosulfonic acid (CSA)/H2O2 and methylmorpholine N-oxide monohydrate (NMMOm) treatments, followed by the common filtering, sonication, and drying processes. The yield of graphene from expanded graphite (EG) powders prepared by the combined CSA/H2O2 and NMMOm treatments (3.0 wt%) was more than five times that from only the NMMOm treatment (0.6 wt%). The produced eGPNc powders had an almost defect-free graphitic structure with good redispersibility in water and an electrical conductivity of 86.9 S/cm from the filtered eGPNc film. The eGPNc film was dispersed at 0.28 mg/mL in water after centrifugation of the 2 mg/mL aqueous solution at 5000 rpm. The aqueous eGPNc solution was utilized as the reaction medium for the in situ polymerization of pyrrole to produce the polypyrrole (PPy)/graphene nanocomposite. The capacitance of PPy measured from cyclic voltammetry (CV) was improved from 122.8 to 278.6 F/g by loading 1 wt% eGPNc onto the nanocomposite. The capacitance of PPy after 1000 CV cycles was improved from 54.0% to 91.0% by loading 3 wt% eGPNc onto the nanocomposite. This improvement in the capacitance and capacitance-stability is due to the in situ formation of PPy in the well-dispersed aqueous graphene solution. Thus, this simple in situ preparation of PPy with eGPNc in water demonstrated the potential for the diverse applications of water-dispersible eGPNc in various water-based systems such as conducting inks, silver wires, and watersoluble conducting polymers (e.g. poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PSS/PEDOT)) for improving their electron conductivity and stability.

복지차량용 전동휠체어의 경로추적에 관한 연구

조우근(Wookeun Jo),안경관(Kyoungkwan Ahn),윤종일(Jongil Yoon),김동우(Dongwoo Kim),임구(Goo Lim),박재현(Jaehyun Park) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

복지차량용 전동휠체어의 경로추적에 관한 연구

조우근(Wookeun Jo),안경관(Kyoungkwan Ahn),윤종일(Jongil Yoon),김동우(Dongwoo Kim),임구(Goo Lim),박재현(Jaehyun Park) 한국자동차공학회 2008 한국자동차공학회 지부 학술대회 논문집 Vol.2008 No.11

This paper is a study on the path-tracking of electronic wheelchair for welfare vehicle and on autonomous driving that vehicles seek for their own position following car. Normal welfare vehicles need an assistant, while those in this paper are designed for the disabled themselves to drive them. So a notion of autonomous driving of electronic wheel chairs and of moving robots is needed. We suggest fuzzy controller in order to control some of all the path planning of electronic wheelchair which is applied to welfare vehicles designed for self driving. And we com pare a capability of PID controller with that of fuzzy controller.

1개 대학 한방병원에서 EMR을 통해 보고된 한약에 의한 약물유해반응의 현황

권영주,조우근,한창호,Kwon, Yeong-Ju,Cho, Woo-Keun,Han, Chang-Ho 대한한방내과학회 2012 大韓韓方內科學會誌 Vol.33 No.4

Objectives : The aim of this study was to systematically investigate herbal-drug-associated adverse drug reactions (herbal ADRs) reports submitted by a single oriental hospital and to analyze the general characteristics, causative agents, clinical manifestations, severity and types of herbal medicines which caused herbal ADRs. Methods : This study proceeded with IRB approval. The data on herbal ADR were collected prospectively from January 2008 to February 2012 by EMR of Dongguk University Ilsan Oriental Hospital. The World Health Organization (WHO)-Uppsala Monitoring Center (UMC) criteria was used to determinate causality for each herbal ADR. WHO-Adverse Reaction Terminology (WHO-ART) System Organ Class (SOC) code and WHO severity category were also used in this study. Results : A total of twenty eight cases were reported. Twenty two cases were assessed to have over possible relations with herbal medication. The gender ratio of these cases were 64.6 percent female and 36.4 percent male, demonstrating no statistical significance. Patients aged over 60 were 59.1%. Gastro-intestinal system was reported to be the most frequently affected organ (38.8%), and followed by psychiatric system (22.4%), and integumentary system (22.4%). The most common clinical symptom was headache (12.2%), followed by diarrhea (10.2%), and pruritus (10.2%). The severity of most cases was assessed to be mild (89.8%). The percentage of moderate ones was 10.2%, and there were no severe cases. Conclusions : Progressive study and further analysis on herbal ADRs are warranted for safety in the clinical use of herbal medicines.

파두 투여 후 호전된 뇌경색 환자의 장마비 치험 1례

양나래,권영주,조우근,최동준,한창호,Yang, Na-rae,Kwon, Young-joo,Jo, Woo-keun,Choi, Dong-jun,Han, Chang-ho 대한중풍순환신경학회 2010 대한중풍.순환신경학회지 Vol.11 No.1

Paralytic ileus is one of the common complications in stroke patients. In western medical treatment, surgery or conservative care is used for treating ileus. In this case, patient diagnosed as paralytic ileus had problems of constipation, or abdominal distension. Therefore the patient were treated with Crotonis Fructus(巴豆), and the patient showed improvement in X-ray findings and these symptoms. So we report this case.