기계적 피로결함 시험편 제조 및 결함 크기 평가

홍재근,김우성,손영호,박반욱 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.1

원자력발전소의 안전성등급 기기에 적용되는 비파괴검사는 실제 결함을 실현한 시험편을 사용하여 결함 탐지능력을 검증하도록 하는 기량검증이 요구되고 있다. 가동중인 원전에서 발생 가능한 균열으로는 기계적 피로균열, 열 피로균열 및 입계부식균열 등이 있으나 본 연구에서는 기계적 피로균열을 대상으로 하였다. 인장 피로하중을 사용하여 기계적 피로결함을 제조하기 위해서 시험편을 설계하였고 원하는 피로결함 파면의 조도를 얻기 위해서 인가하중의 크기 및 사이클 수를 조절하여 피로결함을 발생시켰다. 발생된 결함에 대한 정확한 크기와 위치에 대한 물리적 정보를 얻은 후에 결함이 설계된 크기와 위치에 존재하도록 기밀용접을 실시하였다. 기밀용접 후 잔여 용접 홈은 가스 텅스텐 아크용접 및 플럭스 코어드 아크용접으로 채워졌다. 최종 완성된 피로결함 시험편을 방사선투과검사 및 초음파탐상검사를 통하여 검사한 결과, 설계된 길이와 깊이로 피로결함이 형성되었음을 확인하였다. Performance demonstration with real flawed specimens has been strongly required for nondestructive evaluation of safety class components in nuclear power plant. Mechanical or thermal fatigue crack and intergranular stress corrosion cracking could be occured in the in-service nuclear power plant and mechanical fatigue crack was selected to study in this paper. Specimen was designed to produce mechanical fatigue flaw under tensile stress. The number of cycles and the level of stress were controlled to obtain the desired flaw roughness. After the accurate physical measurement of the flaw size and location, fracture surface was seal-welded in place to ensure the designed location and size. The remaining weld groove was then filled by using gas-tungsten arc welding(GTAW) and flux-cored arc welding(FCAW). Results of radiographic and ultrasonic testing showed that fatigue cracks were consistent with the designed size and location in the final specimens.

소장 질환이 의심되는 환자에서 캡슐내시경과 CT 소견의 비교

이성수,홍성숙,김정훈,김연수,김진오,권석범,박성태,장윤우,최득린,권귀향 순천향의학연구소 2007 Journal of Soonchunhyang Medical Science Vol.13 No.1

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사이비문제로서 동음이의어와 언어의 모호성

홍승우 한국외국어대학교 외국어교육연구소 1997 외국어교육연구 Vol.- No.11

피씨비(PCB) 中毒에 미치는 프라센타(Placenta)의 效果

洪思澳,李香雨,鄭相允 成均館大學校 1983 論文集 Vol.33 No.-

This study was undertaken to investigate the effects of placenta on the toxicity of KC-400 in rabbits. Rabbits were treated with 800㎎ of KC-400 in 2㎖ olive oil via IP injection intermittently day after day for a week and were successively administered with 2㎖ of the placenta extracts via I. V. injection twice a day after day as well as with the placenta extracts with 50 ㎎ of vitamin C as well. The results obtained in this experiment were as follows: 1. When the experimental animals were treated with human placenta, there wasn't any alteration of the hematochemical indicators such as RBC, WBC, Hgb, Het, serum Cholesterol, s-GOT, s-GPT, serum Alkaline Phosphatase and Total lipids in serum. 2. According to the experiment of PCB poisoning, while s-C, s-GPT, s-ALP, and s-TL were increased, RBC, WBC, Hgb and Het were decreased during the experimental periods respectively. 3. The placenta extracts normalized the hematochemical indicators of the PCB poisoned animals after one day treated by the placenta extracts. 4. The combined treatment with the placenta extracts and vitamin C was the same effect as the single placenta treatment only; they were not significant in the t-test. 5. The placenta extracts inhibited the serum tyrosinase activity of the rabbits which was induced by PCB in vivo and in vitro respectively. By the combined treatment with the placenta extracts and vitamin C, the activity of tyrosinase was remarkably inhibited in comparison with the single treatment with the placenta alone.

간첩소지 만년필형 독총의 구조 및 성분

홍성욱,이정필,박성우 內務部 國立科學搜査硏究所 1996 國立 科學 搜査 硏究所 年報 Vol.28 No.-

Cone beam형 전산화단층영상에서 골의 형태와 밀도의 평가

홍상우,김규태,최용석,황의환 대한구강악안면방사선학회 2008 Imaging Science in Dentistry Vol.38 No.1

Purpose : Diagnostic estimation of destruction and formation of bone has the typical limit according to capacity of x-ray generator and image detector. So the aim of this study was to find out how much it can reproduce the shape and the density of bone in the case of using recently developed dental type of cone beam computed tomography, and which image is applied by new detector and mathematic calculation. Materials and Methods : Cone beam computed tomography (PSR 9000N, Asahi Roentgen Ind. Co., Ltd., Japan) and soft x-ray radiography were executed on dry mandible that was already decalcified during 5 hours, 10 hours, 15 hours, 20 hours, and 25 hours. Estimating and comparing of those came to the following results. Results : The change of inferior border of mandible and anterior border of ramus in the region of cortical bone was observed between first 5 and 10 hours of decalcification. The reproduction of shape and density in the region of cortical bone and cancellous bone can be hardly observed at cone beam computed tomography compared with soft x-ray radiography. The difference of decrease of bone density according to hours of decalcification increase wasn’t reproduced at cone beam computed tomography compared with soft x-ray radiography. Conclusion : CBCT images revealed higher spatial resolution. However, contrast resolution in region of low contrast sensitivity is the inferiority of images’ property.

천추 갈색종양(Brown tumor)으로 발현된 부갑상선 기능항진증 1예

홍우정,구본정,이재민,한상우,이효진,나소영,노흥규,김영건,송민호 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

부갑상선 기능항진증에 의한 골병변으로 갈색종양이 있다. 갈색종양은 주로 장골을 침범하고 척추골에서의 발생은 매우 드물다. 국내의 보고에서 갈색종양의 장골 침범은 있었으나, 척추골에서의 발생은 보고된바 없다 .저자들은 부갑상선 기능항진증으로 인하여 척추골의 천추에 발생된 갈색종양 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. The bony involvement in primary hyperparathyroidism present as browm tumor or osteitis fibrosa cystica and lead to pathologic fracture. Brown tumor commonly involve long bone such as femur, tibia, fibula, humerus, and radius. Brown tumor of axial skeleton is a rare entity. Previously reported case that involve axial skeleton still not present. We report a 47-year-old male patient that he has a hyperparathyroidism presenting as brown tumor involving sacrum.

17β-Estradiol의 심근 보호작용에 대한 연구 ; 재관류 부정맥을 유발한 동물실험

홍정석,김원,조규종,이미우,장성은,임경수 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Although reperfusion certainly prevents tissue ischemia from possible cardiac death, several lines of evidence suggest that reperfusion may paradoxically aggravate the frequency of serious reperfusion-induced lethal arrhythmias. It has been reported that acute administration of estrogen at physiological concentrations reduced with myocardial ischemic injury in women with coronary heart disease. In studies with canines, acute administration by either the intra-muscular or the intra-coronary route similarly prevented ischemia and reperfusion dysrhythmias and also reduced the infarct size because the estrogen increased the distal coronary perfusion pressure, scavenged free radicals and had other effects during both ischemia and reperfusion. However, the canine heart is notoriously well collateralized. 17β-estradiol induces very little vasorelaxation in cat coronary rings, suggesting that increased ischemic myocardial blood flow dose not contribute to the protective effect. In the present study, employing a cat model of regional cardiac ischemia, we examined whether reperfusion rendered after acute administration of 17β-estradiol could lower the incidence of reperfusion-induced lethal arrhythmia and the death rate. Method: Adult mongrel male cats(n=31, 2.7∼4.5 kg) were anesthetized under positive-pressure artificial ventilation with room air. Electrocardiograms were recorded. The animals of the control group(n=15) were subjected to 20-minute left anterior descending coronary artery(LAD) occlusion followed by abrupt reperfusion. The animals in the experimental 17β-estradiol(2 or 20 ㎍/kg) group were subjected to ischemia/reperfusion insult following drug treatment: 17 β -estradiol was applied intravenously within the 60 seconds just before LAD ligation followed by abrupt reperfusion. The Fisher's exact test was used to compare the data from different animal groups(p<0.05). Results: The number of arrhythmias(ventricular premature beat, ventricular tachycardia and ventricular fibrillation) emerging during the reperfusion phase were not statistically different from that in the control group. The death rate in the 17β-estradiol 20㎍/kg group was lower from that in the control group(P value = 0.039). Conclusion: Acute administration of 17β -estradiol at a supraphysiological concentration might produce cardioprotective effects, not by modificating the coronary blood flow into the threatened myocardial region, but by other mechanisms that directly or indirectly increase the intrinsic myocardial ischemic tolerance in the cat during the reperfusion phase.

TNF계 CD137L 및 RANKL의 파골세포와 T 세포에 대한 활성조절

홍성준,박재홍,이현우,이긍호 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.4

본 연구는 TNFR family인 CD137 및 RANK. 파골세포의 CD137L와 T 세포의 RANKL 간의 역신호에 의한 이들 세포의 역할을 알아보고자 하였다. 이에 RANKL 및 CD137L 자극으로 유도되는 역신호 전달에 의한 T 세포 활성과 파골세포분화에 미치는 영향을 규명하고자 웅성 생쥐의 골수세포와 T 세포를 공동배양하여 다음과 같은 결과를 얻었다. 1. 생쥐 단핵세포주 및 골수유도 단핵전구세포에서 CD137L이 발현되며, CD137L 단클론 항체로 자극을 주었을 경우 파 골세포 표지단백절인 TRAP 양성 파골세포의 형성이 억제되었다. 2. 활성화된 CD4^(+) 및 CD8^(+) T 세포에서 RANKL을 발현하였으며 RANKL의 유사 수용체인 OPG 재조합 단백질을 처리하여 CD4^(+) 및 CD8^(+) T 세포의 세포증식이 억제되었다. 이 연구의 결과는 CD137자극에 의한T세포활성 및 RANK 자극에 의한파골세포분화및 활성이 각각수용체에 결합하는 라이겐드의 역신호에 의해 억제되었는데, 이는 파골세포와 T 세포의 과도한 활성을 제어하는 생체의 항상성조절에 관여하는 기전으로 생각된다. Resorption of alveolar bone in periodontitis is due to excessive differentiation and activation of osteoclasts. Bacterial antigens causing periodontitis activates CD4 T cells, which leads to expressing RANK ligand (RANKL) on CD4 T cells. RANKL binds RANK on preosteoclasts or osteoclasts, and enhances the differentiation preosteoclasts into osteoclasts and the activation of mature osteoclasts. CD137, one of TNF receptor (TNFR) family, expressed on activated T cells binds with CD137 ligand (CD137L) on antigen presenting cells. Cross-linking of CD137 by CD137L acts as T cell co-stimulatory signals and, therefore, enhances the activation of T cell. In this study, I elucidated the biological responses of CD137L on (pre)osteoclasts and RANKL on T cells in the context of in vivo interaction between T cells and osteoclasts. RAW264.7. murine monocytic cells, constitutively express CD137L. Ligation of CD137L with anti-CD137L mAb inhibited RANKL-induced osteoclast formation in a dose-dependent manner. Bone marrow cells are expressed CD137L by the treatment with M-CSF. Cross-linking of CD137L abolished M-CSF/RANKL-evoked the formation of multi-nucleated osteoclasts. Both mouse CD4 and CD8 T cells are expressed RANKL following their activation. Ligation of RANKL with OPG, the decoy receptor for RANKL, inhibited both CD4 and CD8 T cell proliferation. These effects were attributed to RANKL-induced apoptosis. These data indicate that CD137L and RANKL on osteoclasts and T cells, respectively provide them with inhibitory signal.

문장의미도 다의적이고 모호하다?

홍승우 한국외국어대학교 언어연구소 2001 언어와 언어학 Vol.26 No.-

In sentences which are asserted as ambiguous, it is a matter of one phonic sequence that is connected to several meanings. We lay down them as homonymous sentences. But because of this fact, one should not misinterpret the meaning of the natural language as ambiguous. It has diverse mechanism, with which it helps to identify itself. Our language is used in text in the sense of textlinguistics. Thanks to the hierarchical, syntagmatic, paradigmatic structure and sem-recurrence, one can clearly capture the meaning of a sentence ; under nonlinguistic conditions, above all the direction of the sense, the situation of the conversation, the horizon of the anticipation and the scheme of the act play an important role. The sentences without these conditions are semantically incomplete, although they are syntactically complete. Bei den Sa¨tzen, deren Bedeutungen als mehrdeutig behauptet werden, handelt es sich um eine lautliche Sequenz, die mit mehreren Bedeutungen verbunden ist. Wir bestimmen sie als homonyme Sa¨tze. Aufgrund dieser darf man jedoch dir natu¨rliche Sprache der Ambiguita¨t u¨berhaupt nicht bezichtigen. Denn sie ha¨lt viele nicht-sprachliche und sprachliche Mechanismen bereit, sich selbst zu identifizieren. Die Sprache erscheint in Texten, wenn sie u¨berhaupt gesprochen wird. Dank der hierarchischen, syntagmatischen und paradigmatischen Struktur sowie der Sem-Rekurrenz, die in den Texten zu realisieren sind, kann man die Satzbedeutung eindeutig erfassen; unter den auβersprachlichen Bedingungen spielen vor allem die Sinnrichtung, die Gespra¨chssituation, der Erwartungshorizont und das Handlungsschema eine wichtige Rolle. Die Sa¨tze ohne diese Bedingungen sind semantisch nichts andes als unvollsta¨ndig, auch wenn sie syntaktisch vollsta¨ndig sind. Die Behauptung, die Satzbedeutung sei vage, ist auch falsch, weil sie die Grundsa¨tze der Relevanz und Einfachheit unberu¨cksichtigt gelassen hat. Die Ursache der Hemmung bei der Versta¨ndigung liegt nicht in der Befolgung der Grundsa¨tze, sondern vielmehr in den irrelevanten und unno¨tig verwickelten A¨uβerungen. Daru¨ber hinaus muβ die Unbestimmtheit der Wahrheitsbedingung von der der Satzbedeutung klar unterschieden werden. D.h. man darf aus der ersteren die letztere nicht folgern.