3D flexible Si based-composite (Si@Si₃N₄)/CNF electrode with enhanced cyclability and high rate capability for lithium-ion batteries

Kim, Si-Jin,Kim, Min-Cheol,Han, Sang-Beom,Lee, Gyu-Ho,Choe, Hui-Seon,Kwak, Da-Hee,Choi, Sun-Yong,Son, Byung-Goo,Shin, Myoung-Sun,Park, Kyung-Won Elsevier 2016 Nano energy Vol.27 No.-

<P><B>Abstract</B></P> <P>Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg<SUP>−1</SUP> at a fairly high current density of 10Ag<SUP>−1</SUP> and an extremely low capacity loss for 2000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared Si-composite/CNF exhibits a 3D flexible Si-composite electrode. </LI> <LI> The electrode consists of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers. </LI> <LI> The Si-composite/CNF was directly utilized as an anode. </LI> <LI> Si-composite /CNF exhibited high specific capacity and improved high rate cycling performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

한국인에서 일광노출과 자외선차단제에 대한 인식과 사용 행태 연구

장시혁 ( Si Hyeok Jang ),박현선 ( Hyun Sun Park ),조소연 ( So Yun Cho ),윤현선 ( Hyun Sun Yoon ) 대한피부과학회 2015 대한피부과학회지 Vol.53 No.1

Background: Although sunscreen is used as a primary strategy for the prevention of sunburn, photoaging, and skincancer, few people regularly use sunscreen. Objective: To investigate awareness regarding the effects of sunlight, the extent of sun exposure, and sunscreen usebehaviors in Korean subjects. Methods: A questionnaire was administered to 467 adult patients who visited the Dermatology Department at SeoulNational University Boramae Hospital. The questionnaire covered demographic characteristics, causes of wrinkles,sunspots, and skin cancer, awareness of the harmful effects of sun exposure, perceived and actual extent of sunexposure, and the use of sun-protective methods including sunscreen. Results: Sun exposure was selected as the major cause of age spots (60.6%), skin cancer (60.9%), and wrinkles(25.9%). Respondents were likely to underestimate the extent of sun exposure. On average, quite a few respondentsstated that they were exposed to sunlight for more than one hour per day (22.7% on weekdays, 52.4% onweekends). However, only 9.4% of respondents thought that their sun exposure was problematic and 62.7% ofrespondents considered moderate sunlight exposure healthy. Respondents`` sun-protective behaviors were inadequate:only 29.8% used sunscreen regularly, and 16.5% have never used sunscreen. SPF was the most important factor inchoosing sunscreen, and 83.3% used a sunscreen with a labeled SPF over 30. By contrast, only 34.6% ofrespondents used PA+++ sunscreen. Conclusion: Despite fairly good knowledge regarding the harmful effects of sunlight, subjects underestimated therisks of their sun exposure and sun-protective behaviors were suboptimal. Education on the risk of UV exposure andeffects of sunscreen is still needed. (Korean J Dermatol 2015;53(1):16∼22)

Effects of Si on the Microstructure and Work Hardening Behavior of Fe‒17Mn‒1.1C‒xSi High Manganese Steels

Renlong Xiong,Yi Liu,Haitao Si,Huabei Peng,Shanling Wang,Binhan Sun,Hanxin Chen,Hyoung Seop Kim,Yuhua Wen 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

In order to improve the work hardening capacity under low stresses and the yield strength of conventional Hadfield steels, theeffects of Si on the microstructure and work hardening behavior of the Fe‒17Mn‒1.1C‒xSi steels under both quasi-statictensile and low load impact are investigated. It is shown that the increase of the Si contents remarkably improves the yieldstrength by 36 MPa per 1 wt% Si in the investigated steel system without significant sacrifice of ductility. The decreasingeffect of Si on the stacking fault energy is strongly affected by carbon, although the variation of carbon content was small. This led to the unexpected similar stacking fault energy between 1Si and 2Si steel. With the increase of the Si contents forthe steels, the critical strain for the onset of mechanical twinning was lowered, which was controlled by the cooperationbetween the stacking fault energy and solid solution strengthening of Si. This resulted in the earlier initiation of mechanicaltwins and an increase in the twin volume fraction. Therefore, the work hardening capacities under both quasi-static tensileand low load impact tests were enhanced. It was also found that the impact deformation decreased as more mechanical twinsabsorbed the impact energy.

Effects of Phenytoin and Diazepam on the Seizure Activity in the Cortical Dysplasia Animal Models

Kim, Si-Hyung,Choi, In-Sun,Cho, Jin-Hwa,Park, Eun-Ju,Jang, Il-Sung,Choi, Byung-Ju,Kim, Hyun-Jung,Kim, Young-Jin,Nam, Soon-Hyeun The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Dysplasia-associated seizure disorders are markedly resistant to pharmacological intervention. Relatively little research has been conducted studying the effects of antiepileptic drugs(AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate(MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of AEDs in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injucted control animals. Field potential recordings were used to monitor amplitude and numbers population spikes, and paired pulse inhibition in response to stimulation of commissural pathway. Two commonly used AEDs were tested: diazepam 5, 2.5mg/kg;phenytoin 40, 60mg/kg. Diazepam(DZP) and phenytoin(PHT) reduced the amplitude of population spike in control and MAM-exposed rats. However, the amplitude of population spike was nearly eliminated in control rats as compared to the MAM-exposed rats. Pharmaco-resistance was tested by measuring seizure latencies in awake rats after pilocarpine administration(320mg/kg, i.p.) with and without pretreatment with AEDs. Pre-treatment with PHT 60 mg prolonged seizure latency in control rats, but not in MAM-exposed animals. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard AEDs assessed in vivo. These data suggest that animal model with cortical dysplasia can be used to screen the effects of potential AEDs.

『표해록(漂海錄)』과 『승차록(乘蹉錄)』에 나타난 산동(山東) 인식의 비교

손지수 ( Ji Si Sun ) 경상대학교 남명학연구소 2014 남명학연구 Vol.44 No.-

본고에서는 崔溥의 .漂海錄.과 崔斗燦의 .乘.錄.에 나타나는 두 저자의 산동 인식을 각각의 시대 별로 살펴보았다. 중국 당나라와 원나라는 국제화 정책을 시행하여 많은 유학생을 수 용했다, 그러나 명나라 건국 이후에는 쇄국정책을 실시하여 유학생 수 용을 금지했다. 이로 인해 조선의 선비들은 중국을 경험할 수 있는 기회 가 줄었고, 대체로 책을 통해서 중국을 체험하게 되었다. 명.청 시기, 조선에서 공식적으로 파견한 사신들은 중국에 관한 기록을 남겼으나, 사신의 신분으로는 북경 이남 지역의 경험이 불가능했기 때문에 북경 이외의 지역에 대한 기록은 찾아보기 어렵다. 한편, 비공식적인 漂流人 의 경우 북경 이남 지역을 경험하고 기록을 남기기도 했는데, 그 가운데 崔溥와 崔斗燦의 저작이 가장 대표적이다. 崔溥와 崔斗燦은 표류인의 자격으로 북경 이외의 지역을 경험했으며 이러한 경험이 담겨 있는 .漂海錄.과 .乘.錄.은 연구 자료로서 중요성을 띤다. 성종 연간에 관인 崔溥 일행은 제주도 앞바다에서 태풍을 만나 표류 하게 되었다. 그리고 순조 연간, 장인인 제주 대정현감 金仁澤의 요청으로 제주도로 떠난 崔斗燦은 1년 후 귀향길에서 큰 풍랑을 만나 표류하 게 되었다. 성종 17년(1486) 중국에 표류한 崔溥를 이어, 崔斗燦은 300여년 후인 순조 18년(1818) 중국에 표류했다. 두 시기 모두 조선 왕조는 이어지고 있었지만, 중국은 왕조가 바뀐 완전히 다른 시대였다. 같은 지역이라 하더라도 다른 시대 배경 아래서 겪는 체험과 감상은 다를 수밖에 없었다. 두 시대의 국가 경제와 국민 생활의 차이 등 다양 한 면에서 동이점을 찾아볼 수 있다. 한편으로 崔溥는 조선 시대의 관인 으로서 어명을 받아 .漂海錄.을 작성한 것에 반해, 崔斗燦은 자신의 취미대로 .乘.錄.을 기록했다. 이러한 점 역시 두 텍스트의 차이를 야기했다. 崔溥는 매우 상세하고도 다양한 범위의 내용을 기록했으나, 집필의 의무가 없었던 崔斗燦의 텍스트에는 감정의 표출의 기록과 詩 歌가 빈번하게 나타난다. This study analyzed two authors`` experience in Shandong, represented by their works『漂海錄』 by 崔溥 and『乘蹉錄』by 崔斗燦, according to the era they lived in. The Tang and Yuan dynasties of China had open international policies and accepted many students studying abroad from foreign regions. The establishment of Ming dynasty and adoption of isolationist policy, however, led to abolishment of foreign students. Thus, scholars of Chosun had few opportunities to have experience in China, and resorted to learning about the country through books. In Ming/Qin dynasties, official ambassadors sent from Chosun left records of China, but their access as ambassadors prohibited travel south of Beijing. Therefore, records describing regions outside Beijing are sparse. Yet, unofficial 漂流人 were able to access regions south of Beijing and make records, the most representative of which are works by 崔溥 and 崔斗燦. These authors were able to experience regions outside Beijing as drifters, and 『漂海錄』and 『乘 蹉錄』, which depict their experiences, have significance as important primary sources for research. 崔溥, an official from Seong-Jong``s rule, encountered a typhoon in the seas near Jeju and became a drifter. 崔斗燦, who left for Jeju bythe request of his father in law 金仁澤 - a governor of DaeJung in Jeju, also encountered a big typhoon on his return journey and became a drifter. 崔溥 grounded on Chinese shore in 1486, 17th yearofSeong-Jong``srule,and崔斗燦 grounded 300 years later on 1818, 18th year of Sun-Jo``s rule. While Chosun dynasty had endured through both periods, China had experienced a transition into a completely different dynasty. Thus the experience of living in a different era and rule, even though the physical geography remained the same, had to be changed significantly. With the works, many similarities and differences can be found between the two eras in a range of topics such as national economy and civilian living standards. While崔溥, as an official from Chosun, received royal command to record his experience in 『漂海錄』, 崔斗燦 recorded 『乘 蹉錄』at his own leisure. This contextual difference of the two records contributed to differences in their content: 『漂海錄』covers a wide range of topics in meticulous detail, but 『乘蹉錄』, in which the author had no obligations, often contains records of emotional expressions and 詩歌.

모더니즘 建築物의 意匠的 特性에 關한 硏究

宣時永 건국대학교 1994 論文集 Vol.9 No.-

건축은 건축가가 창작한 형태로 구체적인 실체로서 존재하기 때문에 시각으로써 인간에게 인식되어지므로 건축은 하나의 시각언어로 간주된다. 시각언어는 인간의 시지각을 통해 영상화되어 인간의 내적감응 상태를 유발시키며 인간은 내적감정을 외부로 표출하고자 하는 본능적 욕구를 지니고 있으므로 감응 상태는 곧 언어로서 표출된다. 결국 건축물은 인간의 시각적 경험과 판단에 의한 표현언어로 평가될 수 있으며, 이러한 표현언어는 건축의장 계획시 건축가의 의도에 따른 일반인의 반응을 파악하는 척도가 될 수 있으며, 이는 곧 건축의장 평가의 수단으로써 중요한 의미를 지닌다. 본 연구는 모더니즘 건축의 의장적 맥락을 언어학적 접근방식을 통해 규명한 것으로 먼저 이론적 고찰을 통해 모더니즘 건축의 특성을 평가할 수 있는 형용사 어휘들을 추출하구 그것을 토대로 사조별 모더니즘 건축물의 형태적 특성을 비교 분석 하므로서 모더니즘 건축물 형태의 올바른 이해를 위한 기초자료를 제시하는데 그 목적이 있다. 또하 본 연구는 설문조사 연구로서 평가대상은 9개의 모더니즘 건축물 평가자는 건축물 의장평가에 예비지식을 가진 건축공학과 학생으로 하였으며, 조사된 자료는 빈도, 백분율, 변량분석, 인자분석을 통해 분석하였다. 구체적인 연구결과는 다음과 같다. 1) 모더니즘 건축물의 전반적인 의장적 특성은 크게 형태적 인자, 심미적 인자, 규모적 인자, 등의 3가지 표현언어들로 평가할 수 있으며 이중에서 형태적 인자가 가장 대표적인 평가언어이다. 2) 모더니즘 건축물 사조별로 레이트, 포스트, 네오 모더니즘 건축의 형태적 인자 및 심미적 인자로 평가되는 특성은 차이가 있으나, 규모적 인자의 특성은 차이가 없다. 3) 레이트 모더니즘 건축물은 질서정연하고, 반복적이며, 대칭성과 균일감, 안정감과 통일감, 균형감 등 전반적으로 안정된 느낌을 주는 형태적 특성과 두드러지고 거대하며 강하고 공격적인 느낌의 규모적 특성이 비교적 강하며, 또한 심미적 특성에서는 아름답거나 부드러운 느낌을 주지않는 반면 조화롭고 멋이 있으며 경쾌한 느낌을 준다. 4) 포스트 모더니즘 건축물은 전반적으로 안정된 형태로 인식되며, 특히 질서정연하고 안정감, 대칭성과 반복성, 균형적인 느낌을 주는 형태적 특성이 강하며, 심미적 특성에 있어서는 딱딱하고 단조로우며, 비율동적이고 중엄한 느낌을 가지는 반면, 조화롭고 화려하며, 아름답고 아기자기한 느낌을 강하게 가진다. 또한 규모적 특성은 강하고 거대하며 공격적인 느낌을 가진다. 5) 네오 모더니즘 건축물은 형태적 특성에 있어서 전반적으로 불안전하게 인식되며, 심미적 특성에 있어서는 아기자기하고 멋이 있으며 변화감과 율동적인 느낌을 가진다. 또한 규모적 특성은 공격적이고 대조적이며,두드러진 느낌을 준다. 이상의 연구결과는 9개의 대상 건축물을 제한적 표현언어들로 평가한 것으로 결과의 확대해석에 신중을 기해야 할 것이며, 아울러 앞으로 보다 포괄적인 모더니즘 건축물과 표현어휘들을 이용한 체계적인 연구진행이 요구된다. Architecture is recognized as one of the visual language because architecture is perceived visually by existing as concrete forms created by architects. Visual language can be visualized by person's perception and stimulated person's internal response. person expresces his /her internal response with languages because person has instinct desire to express him / herself externally. Therefore, Aarchitecture can be evaluated with expressive languages created by person's visual experience and judgement. These languages can be the scale to measure public response on architet's intention in architectural design. This study is to research in design factor of modern style buildings through linguistic approach method. The purpose of this study is to suggest the basic data to enhance understanding of architectural forms in Modernism by selecting rhetoric vocabularies to evaluate its characteristics of modern architecture through theoretical research and carring comparative analysis on formal characteristics by 'ism'. The study was conducted by questionaires on nine distinguished modern style buildings -three buildings on each styles of Late, Post and selected data were analyzed through froquency, percentage, means, standard deviation, analysis of variance, and factor analysis. The results of this study were as followings ; 1) Formal characteristics on modern style building can be evaluated by three expressive languages which are formal factors, aesthetic factors, and scale factors. Among them, formal factors is regarded as the most influenced language in evaluating modern style buildings. 2) There is notable difference in formal and aesthetic factors on each styles of modern style building, but no difference in scale factors. 3) Late Modernism Architecture provides stable, united and balanced feeling in formal characteristics, strong, and aggressive feeling in scale factors, and harmonious, tasteful and delight feeling rather than beautiful and soft feeling in aesthetic characteristics. 4) Post -Modernism buildings provide ordered, stable, symmetric repetitive and balanced feeling in formal characteristics, and hard, monotonous, unrythmical and heavy feeling in aesthetic characteristics. 5) Neo-Modernism buildings are not distinguishable in formal and scale characteristics, but provide tasteful, various and rythmical feeling in aesthetic characteristics Above results of the study are outputs of the evaluation on 9 selected buildings as subjects with limited expressive languages. However, extensive interpretation on results should be carried carefully. Further research should be done systematically on extensive subjects and expressive vocabularies.

마크로-고리 화합물을 함유한 액체막의 특성에 관한 연구 : 칼륨 이온 운반에 미치는 음이온 효과

김시중,이심성,이선혜,윤창주 聖心女子大學校 1982 論文集 Vol.13 No.2

디벤조-18-크라운-6가 함유된 액체막을 통한 피크린산칼륨과 요오드화칼륨의 운반속도를 각 칼륨염의 농도 변화에 따라 측정하였다. 음이온의 종류에 따라 운반 메카니즘이 크게 다르게 나타나고 있다. 피크린산칼륨은 이온 확산에 가깝고, 요오드화칼륨은 이온 쌍 확산으로 운반되는 것 같다. The transport mechani는 of potassium picrate and potassium iodide across the liquid membrane containing dibenzo-18-crown-6 were studied by measuring the transport rate of the potassium salts. Potassium picrate seems to be transposted by the ionic diffusion but potassium iodide by the ion-pair.

오리 선위 점액분비세포의 점액질에 대한 조직화학적 연구

류시윤,김홍선,김무강,신태균,이영호 충남대학교 의과대학 지역사회의학연구소 1985 충남의대잡지 Vol.12 No.2

Histochemical sequential staining techniques, PAS, alcian blue pH 2.5 and pH 0.4, were applied to sections from the proventriculus of ducks to observe the histochemical properties of epithelial mucosubstances in the proventriculus of mallard and white Pekin ducks. The whole proventriculus obtained were divided systemically cross strips and processed routinely for histologic and histochemical study. Base on the histologic characteristics, we designated as upper portion which is the distal region of the esophageal-proventriculus junction, as middle portion, and as lower portion which is the proximal region of the proventricular-isthmus junction. The results obtained are as follows 1. Generally in the surface and foveolar epithelia showed the presence of the mixture of neutral and acid mucosubstances. 2. In the tubular gland showed the acidic nonsulfated and sulfated mucosubstance in addition to neutral mucosubstances with occasional neutral and acidic nonsulfated mucosubstances. 3. In the compound gland neutral mucosubstance with scant amounts of acidic mucosubstances or with lack of it were demonstrated. 4. There were recognized differences between speies in the staining intensity of all three types of mucosubstances. 5. There were recognized topographic difference in the acidity of epithelial mucosubstances according to portion.

위협의강도와불안수준에따른위협소구광고의효과연구 : 위협의 발생가능성과 대처반응의 중재효과를 중심으로

이시훈,홍창선 한국방송광고공사 2004 광고연구 Vol.0 No.62

본 연구에서는 위협의 강도와 불안수준, 위협의 발생가능성, 대처반응을 중심으로 위협 소구가 광고효과에 영향을 미치는 구체적인 과정을 살펴보고자 하였다. 구체적으로 위협 소구의 강도(고/저)에 따라 금연캠페인을 주제로 한 두 개의 칼라 인쇄광고물을 제작한 후 사전조사를 통해 실험처치물의 위협의 강도를 구분하였다. 그리고 본 실험은 위협의 강도(고/저)×수용자들의 불안수준(고/저)에 의한 영향을 살펴보기 위해 2×2요인방안으로 설계하였다. 고위협 광고물과 저위협 광고물을 240명의 대학생들에게 보여준 후 위협의 발생가능성, 대처반응, 광고효과를 각각 측정하였다. 연구결과 위협소구의 강도와 불안수준 정도에 따른 위협의 발생가능성에 대한 차이는 나타나지 않았지만, 위협의 발생가능성이 높을수록 문제 회피반응은 낮아지는 것으로 나타났다. 또 문제회피반응은 광고태도, 금연태도와 같은 태도차원의 광고효과에 영향을 미치는 것으로 나타났다. This study aims to examine detailed process that fear appeal has an influence on the advertisement effects focusing on the strength of fear, the level of anxiety, the occurrence probability of fear and coping response. That is, it aims to contribute to establishing proper fear effect strategy by examining the effects of fear appeal through detailed cause and effect process. As a result of verifying the hypothesiss, the follows found; Firstly it was found that the difference in the probability of occurrence according to the level of anxiety and the strength of fear appeal was insignificant. Secondly it was found that the problem solving response did not become higher as the probability of occurrence becomes higher, but problem avoiding response did not become lower as the probability of occurrence becomes higher, and this hypothesis was partially adopted. Lastly the problem solving response did not affect the advertisement effect. However, problem avoiding response was found to affect the advertisement effect of attitude such as advertisement attitude and antismoking attitude.

24시간 활동 혈압에 의해 진단된 백의 고혈압의 임상적 특성

맹선희,조홍근,박시훈,신길자,이동수,임양희 梨花女子大學校 醫科大學 醫科學硏究所 1997 EMJ (Ewha medical journal) Vol.20 No.4

목적: 혈압은 의사가 측정할 때 승압반응에 의해 실제값보다 흔히 높게 측정된다고 알려져 있는데 이러한 특성 때문에 내원시 측정한 수시혈압이 실제 활동중 혈압과 차이가 있어 고혈압의 진단, 치료시기의 결정 및 효과의 판정등에 영향을 미치게 된다. 저자들은 24시간 활동 혈압을 시행받은 대상중 수시혈압은 고혈압의 진단기준에 맞으나 백의 고혈압으로 판명된 군의 특성을 알아보고자 본 연구를 시행하였다. 방법: 1995년 1월부터 1996년 7월까지 이화여자대학교 부속 동대문병원을 방문하여 24시간 활동혈압을 시행받은 총 434예의 환자중 잭의 고혈압으로 진단된 13예의 환자를 대상으로 하였다. 대상환자의 병력청취, 내원시의 수시혈압측정, 12극 표준 심전도, 흉부 X선 촬영, 형중 지질농도 검사, 심초음파 검사 및 24시간 활동중 혈압을 분석하였다. 결과 : 1) 백의 고혈압으로 진단된 환자는 24시간 활동 혈압을 시행받은 총 434예의 환자중 13예로 2.99%였으며 남자가 6예, 여자가 7예였다. 대상환자의 연령분포는 26세에서 65세까지로 평균 연령은 45±12세였다. 2) 흉부 X-선 검사는 11예에서 시행받았으며 심장흉부강비가 0.5 이상인 경우는 2예(18.2%). 정상인 경우가 9예였다. 12극 표준 심전도 검사는 모든 대상 환자에서 시행하였으며 모두 정상 동율동이었고 4예(30.8%)에서 죄심실 비대 소견을 보였다. 3) 생화학적 검사에서 혈중 콜레스테롤 189±34mg/dl. 중성지방 139±64mg/dl. 고밀도 지단백 콜레스테롤 100±27mg/dl 로 모두 정상 범위를 보였다. 4) 심초음파 검사는 8예에서 시행받았으며 좌심실질량은 90.7±11g/m^3로 모두 정상이었으나 1예에서 동심성 좌심비대의 소견을 보였다. 5) 좌심실 구혈율은 모두 정상범위였으며 평균 60.8±8.7%였다. 6) 좌심실 이완기지표인 승모판 혈류 속도 지표는 E velocity 0.71±0.14m/sec. A velocity 0.54±0.24m/sec E/A ratio 1.6±0.8. 감속시간(MVDT) 214±27.6m/sec. 등용적성 이완기시간(IVRT) 104±11.4m/sec으로 정상이었으며 1예에서만 비정상 소견을 보였다. 7) 외래에서 측정된 수시혈압의 평균은 수축기 혈압이 159±13.8mmHg. 이완기혈압이 101±9.0mmHg였으며 24시간 활동 평균 수축기 혈압은 128±4.9mmHg. 평균 이완기 혈압은 82±6.6mmHg였다. 백의효과는 수축기와 이완기 각각 31.7±14.1mmHg와 19.5±8.0mmHg였다. 24시간 활동 혈압에서 systolic pressure losd는 12.9±8.4%였고 diastolic pressure load는 21.4±15.3%였다. 8)24시간 활동 혈압에서 수축기 혈압의 야간 주간 혈압비는 0.93±0.06이었으며 이완기 혈압의 야간 주간 혈압비는 0.92±0.06으로 혈압의 일내 변동이 소실된 소견을 보였다. Dipper는 5예(38.5%), Non-Dipper는 8예 (61.5%)였다. 9) 백의 고혈압 진단 후 추적 기간중 고혈압으로 진단되어 항고혈압제를 투여받은 환자는 2예(15%)였다. 결론: 백의 고혈압은 24시간 활동 혈압으로 진단할 수 있으며 이들 환자의 백의 효과가 심장에 미치는 영향은 확실하지 않다. 본 연구에서도 좌심실의 수축기나 이오나기 기능은 정상이었으나 24시간 활동 혈압상에서 일내 변동을 보이지 않는 경우가 61.5%로서 정상 혈압군에서 보이는 소견과는 다르며 13예중 2예(15%)에서 고혈압으로 진단되어 항고혈압제를 투여받고 있으므로 이들에 대한 조기 발견과 정기적 추적 관찰이 중요하며 심혈관계에 대한 영향 및 지속성 고혈압과의 연관성, 치료 방침의 결정에 대한 연구가 필요할 것으로 생각된다. Objectives : The Measurement of blood pressure by a doctor may trigger a pressor response, so there are marked differences between office and ambulatory or self-measured blood pressure and the subjects may misdiagnosed as hypertensives and receive unneccesary medication. The study is designed to evaluate the charicteristic of white coat hypertension, the degree of white coat effect and the relationship between the white coat hypertension and persistent hypertension. Methods : Thirteen patients with office hypertension receiving no medication, were recruited from 434 patients experienced in ambulatory blood pressure. Past history, physical examination, office blood pressure, 12-channel standard electrocardiography, chest X-ray, plasma lipid battery, echocardiography and 24-hr ambulatory blood pressure monitoring with BP3 MEDIANA were performed. Results : 1) White coat hypertensive patients were 13 of 434 patients(2.99%) who were performed 24-hr ambulatory blood pressure monitoring. The mean age was 45±12 years with 6 men and 7 women and rage of age was 26-65 years. 2) The lipid battery, chest X-ray and 12-channel standard electrocardiographty showed no significant finding. 3) The LV mass index was 90.7±11.0g/m^3 but one of 8 who performed echocardiography showed concentric hypertrophty. 4) The LV ejection traction was 60.8±8.7% which normal range. 5) The mitral flow velocity parameters were E velocity 0.71±0.14m/sec, A velocity 0.54±0.24m/sec, E/A ratio 1.6±0.8, mitral valve deceleration time 214±27.6msec and isovolumic relaxation time 104±11.4msec but one of 8 showed LV relaxation abnormality. 6) The mean office systolic blood pressure was 159±13.8mmHg, mean office diastolic blood pressure 101±9.0mmHg, 24-hr mean ambulatory systolic blood pressure 128±4.9mmHg and 24-hr diastolic bliid pressure 82±8.6mmHg. 7) The night day ratio of systolic blood pressure was 0.93±0.06 and the night day ratio of diastolic blood pressure was 0.92±0.06 suggestive of blunted diurnal variation. The Dipper were 5 of 13 patients(38.5%) and the non-Dipper were 8 of 13 patients(61.5%). 8) Two of 13 white coat hypertensives were diagnosed as persistent hypertensives in follow-up periods and antihypertensive drug had been initiated. Conclusion : White coat hypertension can be diagnosed by 24-hr ambulatory blood pressure monitoring. The influence of white coat effect to cardiovascular system was not established. Sixty-two percent of white coat hypertensives showed blunted diurnal variation in 24-hr ambulatory blood pressure monitoring and two of 13 were diagnosed as persistent hypertensives in our F/U study, so white coat effect cannot be merely innocent and need strict evaluation and regular follow-up.