일랙트렛트의 응용

황명환,이덕출 한국전기전자재료학회 1993 전기전자재료학회지 Vol.6 No.4

일렉트렛트이란 자석과 대칭한 호칭으로 영구전기분극을 갖는 절연체를 말한다. 일랙트렛트는 1919년 강구에 의해 창제되었는데 이것은 왁스와 송지를 등량으로 혼합하여 만든것이었으나 최근에는 테프론이나 마이러, 폴리프로필렌등의 고분자 필름으로 만들게 되었다. 많은 고분자 재료는 절연성이 좋고 가공 성형도 용이하기 때문에 일랙트렛트로 하기에 편리하다. 그중에서도 합성고분자 필름에 의한 일랙트렛트는 마이크로폰이나 카트리지 등의 음향소자에 쓰이는 외에 정전모우터, 릴레이스위치, 에어필터나 의용재료에 널리 이용될 가능성이 나오고 있다.

염소 처리된 저밀도 폴리에틸렌 필름의 산화 및 기계적 완화 특성

황명환,박동화,박구범 한국산업안전학회 1991 한국안전학회지 Vol.6 No.3

이 논문은 폴리에틸렌 필름을 염소처리해서 부분방전에 대한 내산화특성 및 염소처리필름과 γ선조사 필름의 분자운동에 대해 조사한 것이다. 1. 염소 처리한 PE 필름의 표면을 연마해서 C-Cl 이 10㎛ 깊이까지 분포하고 있음을 알았다. 2. 염소화가 진전하면 결정화도가 감소하며 가교가 발생한다. 3. 염소화 PE는 부분 방전에 의해 생기는 오존의 산화를 억제하고, 자신은 결합했던 염소를 잃는다. 4. 염소처리를 행하면 PE의 CH2 주쇄의 운동인 γ 흡수가 염소치환에 의해 감소한다. This paper is for the properties of the oxidation-proof of the partially discharged and of the molecular motion on chlorinated PE Film. this paper also shows the properties of the molecular motion of the γ ray irradiated PE Film. 1. In the surface of the PE Film enforce chlorination, C-Cl be distributed up to 10 ㎛ deep. 2. In according to the development of the chlorination, the measure of crystalization decreased and cross link occured 3. Chlorination PE Film control the oxidation on ozone to occuration by partial discharge and it lost bonding chlorine. 4. In according to chlorination, γ absorption in motion of CH2 main chain of PE decreased by chlorine stbstitution.

폐수중 티오시안산이온을 측정하기 위한 계면활성제를 이용한 고분자 막전극

황명환,우인성,최종석,강안수,안형환 한국산업안전학회 1991 한국안전학회지 Vol.6 No.4

Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 330T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3㎜. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows : ClO₄^->I^->NO₃^->Br^->F^->Cl^->OA_0◎SO₄^(2-).

고분자 film 의 표면 처리와 화학 루미네센스 특징

황명환,우인성 한국산업안전학회 1992 한국안전학회지 Vol.7 No.4

Surface treatment and chemiluminescence characteristics of the polymer film. It was studied that the intensities and rates of treatments are in proportional to condition of the treatment, considering the results of study on treatments to polymer film with discharge and ultraviolet irradiation through the methods such as surface resistance, contact angle, dyeing method, surace tension and so on. It was also studied that the said has a nice correlation with the concerned result studied by chemiluminescence. Since the chemiluminescence will enable the investigators to grasp a eertain condition caused by quitely slight deterioration with high sensitivity, it can be also used as a way for getting an information regarding the decision for degradation-condition and life-estimating of insulation material basically related to some security matters as well as surface condition of treatments through the above method.

방전 프라즈마 화학반응을 이용한 유해물질의 분해

황명환,우인성,산외번장 한국산업안전학회 1996 한국안전학회지 Vol.11 No.4

이종방전 중첩에 의한 방전 플라스마반응기의 효율개선의 시도 : 연면 , 직류코로나 방전 중첩형 반응기의 특성 Characteristics of Surface and Corona Discharge Combined Plasma Reactor

황명환,우인성,산외서수 한국산업안전학회 2000 한국안전학회지 Vol.15 No.3

In order to cope with environmental problems caused by harmful gases emitted from various industrial sources, a new technology which employs discharge plasma formed in ordinary atmospheric pressure has been intensively investigated in many industrialized nations. Although a plenty of useful outcomes and suggestions have been made public by scientists in this field, few commercial products which effectively decompose pollutant gases have appeared as yet. This is partly because that the energy efficiency of a most effective plasma reactor has not reached a satisfactory level in comparison with those of devices using conventional technologies. In an attempt to solve the problem mentioned above, we noticed to combine heterogeneous electrical discharges. This concepts is based on that each plasma reactor has its specific spatial region in which chemical reaction are active and by electrically affected with another reactor of different type, the activated region would increase - which may lead to cutting down the energy consumption. To prove this concept experimentally, two different discharge equipments, a plane ceramic-based surface discharge electrode and a corona electrode with tungsten needle array, are selected and combined to fabricate a hybrid plasma reactor. The results are summarized as follows; (1) Ozone concentration generated in the plasma region drastically increases when the positive corona discharge is added to the surface discharge. The rate of increase of ozone depends on the frequency of the surface discharge. The negative corona, however, does not contribute to the improvement of the ozone generation. (2) NO(nitrogen monoxide) decomposition rate also improves by simultaneously applying the surface and the positive corona discharges. The effect of the corona superposition is more evident when the level of the surface discharge is moderate. (3) By adjusting the corona level, the net energy efficiency during NO decomposition improves in comparison with the simple surface discharge reactor.

모래에 침지시킨 방향족 유기용제의 연소특성

황명환,우인성,정덕채 한국산업안전학회 2000 한국안전학회지 Vol.15 No.3

Combustion characteristics of immobilized benzene and toluene in sands were studied. Experiments were performed by burning benzene and toluene immobilized on sands(particle size 0.10∼0.5㎜) to measure combustion rate and combustion temperature. The longer time from ignition to extinguishment was resulted from the larger particle size exhibited the higher mass burning rate. Of aromatic compounds tested the relative magnitude of facilitation of combustion was benzene and toluene. Combustion temperature of benzene and toluene without regard to the types of benzene and toluene was not increased with smaller sand. However, with larger sands, combustion temperature of benzene and toluene were increased by 50∼ 100℃ and the highest combustion temperature was obtained with larger sands.

艮齋 李德弘의 한시에 나타난 교유의 양상과 그 의미

황명환 대동한문학회 (구.교남한문학회) 2022 대동한문학 Vol.70 No.-

Lee Deok-hong was taught by Toegye Lee Hwang. And since then, he had social intercourse with his teacher and alumni in various ways. This social intercourse continued even after the death of his teacher Toegye. In the process, a number of sino-Korean poetry directly related to social intercourse were created. In fact, it is supported by the fact that 71 of the 181 sino-Korean poetry are chaun-si(次韻詩). The aspects of social intercourse that appeared in The Lee Deok-hong's sino-Korean poetry can be divided into three main types. The first is the succession of Toegye studies through lectures. Lee Deok-hong revealed his perception of following his teacher's teachings through chaun-si. And in the process of discussing studies with alumni, he worked tirelessly to pass on what he had learned from his master. In addition, he expressed his pride in the origin of the study from Chu Hsi(朱熹) to Toegye, and based on this, he showed the will of learning to his alumni. Second, it is the expression of pung-ryu(風流) through boating and travel. After being taught by Toegye, Lee Deok-hong began full-fledged pungryu activity. In particular, the boating performed at Takyeongdam(濯纓潭) with Toegye was comparable to the boating at the Jeokbyeok(赤壁). In addition, he enjoyed the pung-ryu at Cheongryangsan(淸凉山) with his alumni or went to a nearby place. At this time, what was as important to him as the beautiful natural scenery was the existence of the person traveling together. Third, it is to overcome the regret of parting by writing a sino-Korean poetry at the time of parting. Lee Deok-hong wrote a Jeung-Byeoul-Si(贈別詩) to an alumni who was about to part, or delivered a Jeung-Si(贈別詩) to an alumni who was far away, expressing regret for the breakup. However, he expressed his expectations not only to expressed his regret, but also to hoped that alumni's orientation would not change, while expressing his anticipations for returning safely from their mission. Looking at the meaning of social intercourse in Lee Deok-hong's sino-Korean poetry, it can be said that he promoted scholastic unity based on respect for his teacher. In addition, his Pungryu activities were mainly conducted in the Yeongnam(嶺南) area, so naturally, he re-aware of the Yeongnam area's landscapes and paid attention to the Yeongnam ancient sages. And as shown in Lee Deok-hong’s farewell sino-Korean poetry, it was possible that he was able to promote academic and regional unity because the deep trust in alumni.

한국어교육능력검정시험 ‘한국문화’ 영역 문항 분석 연구 - 내용타당도 확보 방안을 중심으로 -

황명환,민진영 한국문화융합학회 2022 문화와 융합 Vol.44 No.8

본 연구의 목적은 한국어교육능력검정시험의 네 번째 영역인 ‘한국문화’ 영역의 내용타당도 확보 방안을 모색하는 것이다. 이를 위해 한국어교육 전문가들의 의견 수렴을 통해 한국문화 영역에 대한 실질적인 출제 범위를 제안하였다. 그리고 한국문화 과목과 하위영역의 출제 빈도를 살펴보고 문항반응이론을통해 한국문화 영역 문항에 대한 난이도와 변별도를 검토하였다. 본 연구 결과를 요약하면 다음과 같다. 첫째, ‘한국문화’ 영역의 적정 출제 범위는 한국의 현대문화, 한국 역사, 현대한국사회 과목 및 그하위 영역인 것으로 나타났다. 둘째, 제안된 적정 출제 범위를 바탕으로 문항 출제 경향성을 파악한 결과, 현대한국사회 관련 문항의 출제 빈도는 한국의 현대문화 및 한국역사 관련 문항 출제 빈도보다 극히 적게 확인되었다. 셋째, 문항 난이도와 변별도 분석 결과, 극단적 난이도와 변별도 출현이 다수 목격되었다. 최종적으로 본 연구 결과를 토대로 한국어교육능력검정시험의 ‘한국문화’ 영역의 내용타당도확보를 위한 실제적인 방안이 논의되었다.

MR Imaging of Rat Glioma using Polysorbate-coated Magnetic Nanocrystals as a Blood-Pool Contrast Agent

황명환 한국실험동물학회 2012 한국실험동물학회 학술발표대회 논문집 Vol.2012 No.8