플라이 애쉬가 콘크리트 구조물의 철근 부식에 미치는 영향

박진택,유지홍,김정구,이재호,이광명 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.4

Addition of fly ash has beneficial effects on some mechanical properties of concrete, as well as the corrosion process induced by the chloride ion. The aim of this study was to investigate the effect of fly ash on the steel corrosion in concrete with various water-to-binder ratios. The corrosion process of steel bars embedded in concrete without fly ash and with 20% fly ash was tested under complete immersion, in 3.5 wt.% NaCl solution. Monitoring of open-circuit potential and linear polarization method and electrochemical impedance spectroscopy(EIS) were used to follow the corrosion process. Also, ASTM C1202 test method was used to estimate the concrete's resistivity of chloride penetration in concrete. The results obtained from electrochemical tests show that the use of fly ash has led to the improvement of corrosion resistance. Partial cement replacement by fly ash caused significant pore refinement, reduced permeability to chloride ions, and increased corrosion resistance.

Solid-State Scrolls from Hierarchical Self-Assembly of T-Shaped Rod–Coil Molecules

Hong, Dong-Je,Lee, Eunji,Jeong, Haemi,Lee, Jeong-kyu,Zin, Wang-Cheol,Nguyen, Trung Dac,Glotzer, Sharon C.,Lee, Myongsoo WILEY-VCH Verlag 2009 Angewandte Chemie Vol.48 No.9

<P>On a roll: Attachment of flexible coils to the middle of a rigid rod generates T-shaped rod–coil molecules that self-assemble into layers that roll up to form filled cylindrical and hollow tubular scrolls, depending on the coil length, in the solid state (see picture); the rods are arranged parallel to the layer plane. <img src='wiley_img_2010/14337851-2009-48-9-ANIE200804307-content.gif' alt='wiley_img_2010/14337851-2009-48-9-ANIE200804307-content'> </P> <B>Graphic Abstract</B> <P>On a roll: Attachment of flexible coils to the middle of a rigid rod generates T-shaped rod–coil molecules that self-assemble into layers that roll up to form filled cylindrical and hollow tubular scrolls, depending on the coil length, in the solid state (see picture); the rods are arranged parallel to the layer plane. <img src='wiley_img_2010/14337851-2009-48-9-ANIE200804307-content.gif' alt='wiley_img_2010/14337851-2009-48-9-ANIE200804307-content'> </P>

인공신경망 기반 히트펌프 에너지 예측에 관한 연구

홍성협(Hong, Sung-Hyup),이종만(Lee, Jong-Man),박민경(Park, Min-Kyeong),이영준(Lee, Young-Jun),지현진(Zi, Hyeon-Zin),이광호(Lee, Kwang Ho) 대한건축학회 2021 대한건축학회 학술발표대회 논문집 Vol.41 No.1

Bcl-2 and c-myc protooncogene expression in cervical intraepithelial neoplasia and cervical carcinomas

김병기 ( B. G. Kim ),( T. H. Um ),( Y. J. Zin ),( J. M. Lee ),( J. H. Kim ),( S. Y. Park ),( E. D. Lee ),( K. H. Lee ),( K. B. Park ),( S. S. Lee ),( S. I. Hong ) 대한산부인과학회 1996 대한산부인과학회 학술대회 Vol.78 No.-

Antiferroelectric Liquid Crystal from Bent-Core Molecule with Vinyl End Group

Lee, Chong-Kwang,Kwon, Soon-Sik,Kim, Tae-Sung,Shin, Sung-Tae,Choi, Hong,Choi, E. Joon,Kim, Sea-Yun,Zin, Wang-Choel,Kim, Dae-Choel,Chien, Liang-Chy Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.8

Three banana-shaped achiral compounds, 4-chloro-1,3-phenylene bis [4-{4-(undecenyloxy)phenyl imino-methyl} benzoate] derivatives, were synthesized with variation of a substituent (x=H, F, Cl); their antiferro-electric properties are described. The smectic mesophases, including a switchable chiral smectic C(Sm $C^{\ast}$) phase, were characterized by differential scanning calorimetry, polarizing optical microscopy, triangular wave method, and X-ray diffractometry. The presence of vinyl groups at the terminals of linear side wings in the banana-shaped achiral molecules induced a decrease in melting temperature and formation of the switchable Sm $C^{\ast}$ phase in the melt. The smectic phase having a lateral fluorine-substituent at 3-position of the Schiff's base moiety showed antiferroelctric switching, and the value of spontaneous polarization on reversal of an applied electric field was 250 nC/$cm^2$ .

구속형 가스 분무 조업 시 동적 흡입 압력 특성에 관한 연구

홍승표,이진형,오방원 대한금속재료학회(대한금속학회) 1992 대한금속·재료학회지 Vol.30 No.9

Melt flow rate is considered to be an important process variable in gas atomization because it greatly affects the droplet sizes, microstructures and mechanical properties of the final products. It is, however, difficult to predict the melt flow rate accuratly because it is also influenced by the aspiration pressure under the melt orifice in confined type gas atomization. It seems to be impossible to measure the orifice pressure directly during gas atomization. Hence upto now the orifice pressure has been measured statically with the pressure gage connected to the upper side of melt orifice without flow. But it is different from the real atomizing conditions, in which melt flows through the orifice. In this study, the dynamic orifice pressure was calculated by measuring the flow-out time of the melt. The dynamic aspiration effect varies with the protrusion height of melt nozzle, increases with the increasing gas jet velocity and decreases as melt flow rate increases.

한국인에서 21-hydroxylase 결핍에 의해 초래되는 선천성 부신피질 과형성의 유전자형과 임상형에 관한 연구

김흥식,박성준,이진성,이동환,진동규,오필수,김덕희,유한욱,송승미,김정심,황혜진,온화영,고시환,엄미령,신재훈,한헌석,고철우 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.2

Background : Congenital adrenal hyperplasia(CAH) results from an inherited defect in enzymatic steps required to synthesize cortisol from cholesterol. 21-hydroxylase deficiency accounts for 95% cases of CAH. It appears that the frequency and the type of the responsible mutations differ according to the ethnic background and the type of mutation can predict the clinical outcomes such as salt losing type(SL), simple virilizing type(SV) and non-classic type(NC). Methods : We have analyzed CYP21 genes in 55 Korean cases(110 chromosomes) of CAH by Southern blotting, PCR-dot hybridization and PCR amplification-created restriction site method. The patients include 43 cases of SL and 12 of SV. None of the NC was found. Results : We found the mutations in 94%(103/110) of the examined chromosomes. A total of 10 types of mutations were discovered. The mutations include aberrant splicing of intron 2(i2, 35%), CYP21 gene deletion(32%) and I172N(11%) in order. When the relationship between the clinical types and genotypes were correlated, most of the SL patients have either i2(42%) or CYP21 gene deletion(41%), while SV patients have I172N(33%) or P30L(21%). The parents' mutation was investigated in 20 cases. In 4 families, one of the parents was not the obligatory heterozygote carrier i.e. did not have a mutation. The results suggest the high incidence of de novo mutation. Conclusion : We have identified the frequency of mutations of the CYP21 in Korean AGS patients. Our results shows that the clinical type of AGS can be predicted from the genotypes of CYP21. Also the high incidence of de novo mutation of CYP21 confirmed the genetic instability of major histocompatibility III region where the CYP21 is located(J Kor Soc Endocrinol 15:237-247, 2000).

Fabrication and estimation of the plastic detector for measuring the contamination for beta-ray level of the kind of duct waste

Gye-Hong Kim,Won-Zin Oh,Kune-Woo Lee,Bum-Kyoung Seo 한국방사성폐기물학회 2005 방사성폐기물학회지 Vol.3 No.3

원자력 시설의 해체 시 발생되는 다양한 종류의 폐기물 중에서 배관류를 재활용하거나 처분하기 위해서는 배관 내부의 정확한 방사선학적인 오염 특성의 평가가 선행되어야 한다. 그러나 기존의 측정법인 survey-meter를 이용한 오염도의 직접 측정은 배관 내부와 같은 국소지역의 오염 특성을 정확하게 평가할 수 없으며, 간접법을 이용한 표면오염도 측정의 경우도 시료채취의 어려움뿐만 아니라 시료채취 시 작업자의 오염 가능성이 있기 때문에 적용성에 많은 문제점이 있다. 본 연구에서는 Monte Carlo 모사기법을 이용해 직경이 작은 배관 내부의 베타선 오염도를 측정하기 위하여 플라스틱 섬광체를 모사하였으며, 모사 결과에서 베타선 에너지를 효율적으로 측정할 수 있는 최적의 플라스틱 섬광체 두께 및 형상을 도출할 수 있었다. 이 전사모사 결과를 바탕으로 섬광체의 가공 및 배관 내부에서의 검출기 이송 문제를 고려해 검출기를 제작하였으며 그 특성을 평가하였다. 그 결과 배관 내부의 오염도 측정에 적합한 검출기 성능을 확인하였고, 파이프 내부처럼 국소 지역의 방사선학적 오염 특성 평가를 위한 검출기 개발 가능성을 확인하였다. The characterization of radiological contamination inside pipes generated during the decommission of a nuclear facility is necessary before pipes can be recycled or disposed. But, existing direct measurements of radioactive contamination level using the survey-meter can not estimate the characteristic of contamination on a local area such as the pipe inside. Moreover, the measurement of surface contamination level using the indirect methods has many problems of an application because of the difficulty of collecting sample and contamination possibility of a worker when collecting sample. In this work, plastic scintillator was simulated by using Monte Carlo simulation method for detection of beta radiation emitted from internal surfaces of small diameter pipe. Simulation results predicted the optimum thickness and geometry of plastic scintillator at which energy absorption for beta radiation was maximized. In addition, the problem of scintillator processing and transferring the detector into the pipe inside was considered when fabricating the plastic detector on the basis of simulation results. The characteristic of detector fabricated was also estimated. As a result, it was confirmed that detector capability was suitable for the measurement of contamination level. Also, the development of a detector for estimating the radiological characteristic of contamination on a local area such as the pipe inside was proven to be feasible.

Infrared Spectra and Electrical Conductivity of The Solid Solutions X MgO + (1-X) ${\alpha}-Nb_2$ $O_5$; 0.01{\leq}X{\leq}0.09

Park Zin,Park, Jong Sik,Lee Dong Hoon,Jun Jong Ho,Yo Chul Hyun,Kim Keu Hong Korean Chemical Society 1992 Bulletin of the Korean Chemical Society Vol.13 No.2

Changes in network structures of ${\alpha}-Nb_2O_5$ in the X MgO+(1-X) ${\alpha}-Nb_2O_5$ solid solutions occurring as the MgO doping level (X) was varied were investigated by means of infrared spectroscopy and X-ray analysis. X-ray diffraction revealed that all the synthesized specimens have the monoclinic structure. The FT-IR spectroscopy showed that the system investigated forms the solid solutions in which $Mg^{2+}$ ions occupy the octahedral sites in parent crystal lattice. Electrical conductivities were measured as a function of temperature from 600 to $1050{\circ}$ and $P_{O2}$ form $1{\times}10^{-5}$ to $2{\times}10^{-1}$ atm. The defect structure and conduction mechanism were deduced from the results. The $1}n$ value in ${\alpha}{\propto}{P_{O2}^{1}n}}$ is found to be -1/4 with single possible defect model. From the activation energy ($E{\alpha}$ = 1.67-1.73 eV) and the1/n value, electronic conduction mechanism is suggested with a doubly charged oxygen vacancy.

精神症狀에 대한 韓國人의 態度調査

元鎬澤,洪元植,張煥日,陳聖太,金光日,李基南,嚴龍燮,金明正 大韓神經精神醫學會 1973 신경정신의학 Vol.12 No.1

Korean psychiatrists are more apt to take the abnormal drinking behavior lightly and regard the psychosomatic symptoms as more serious, comparing with American psychiatrists. On the other hand, physicians as well as adults from the population in Korea are less concerned about the neurotic and psychosomatic symptoms and alcoholic behavior as psychiatric problems. It is the authors' concern to understand such differences in opinion about abnormal behaviors from the cultural and social psychiatric view point. The authors used Dohrenwend's questionaire form of 45 mental symptoms and three additional items i. e., homosexual behavior, symptom of senile psychosis and delusion of jealousy following the authors' interests. Each item was rated by three point cale (psychiatrically very serious=2 points, somewhat serious=1, not serious at all=0) and evaluated with critical ratio. As a preliminary study, the reliability of this questionaire was confirmed by the test-retest method; Spearman's rho was 0,93. The subjects in this study consist of 50 psychiatrists, 49 physicians, 54 herb practitioners and 154 adults from the normal population(60 urban samples and 94 rural samples). The collection was carried out by individual interviews for the physicians and normal samples, by letters for the psychiatrists and the herb practitioners. And the data of American psychiatrists compared in this study were quoted from Dohrenwend's report(27). This study has two parts: one is the cross-cultural comparison between American psychiatrists and Korean ones, the other is intracultural comparison among psychiatrists, physicians, herb practitioners and normal population samples. Inspite of the general notion that Korean psychiatry has been much oriented to American psychiatry for over twenty years, there are definite differences in opinion about the severity of abnormal behaviors between American and Korean psychiatrist, especially about alcoholic behavior and psychosomatic symptoms. Such differences are possibly interpreted as arising from the cultural differences. The American psychiatrists seem to be more concerned about alcoholic behavior probably due to the strict attitude of people and/or the fact that the United States reveals the highest incidence of alcoholism throughout the world. The Korea psychiatrists, however, have much tolerable attitude toward alcoholic behavior according to the cultural tradition. Solitary drinking is hardly found in Korea; drinking in Korea is a suitable way of interpersonal contact. They drink slowly and are not so intensively dependent upon alcohol itself. Dependency need to alcohol can be diffused to the other persons. And they take alcohol with many kinds of side-dishes. These drinking manners seem to be cultural virtues for low incidence of alcoholism in Korea. Thus, Korean psychiatrists as well as adults from normal population have highly tolerable attitude toward alcoholic behavior. Even when some person reveals a destructive behavior after drinking, they grant it as a personal charm. Korea psychiatrists, therefore, are not so nervous about the alcoholic behavior. On the other hard, the psychosomatic problems seem to be serious in Korean mental patients. They are easily apt to express their emotional problems as somatic symptoms possibly due to the disease concept of oriental herb medicine that has a high tendency of projection of emotional conflicts unto the soma. So most of Korean people are not aware that psychosomatic symptoms are originated from the emotional problems, and quite contrary to it, the psychiatrists may be highly conscious of psychosomatic symptoms. Another significant difference is seen in suicidal idea and suspiciousness: American psychiatrists regard them as more serious, and reversely Korean psychiatrists regard them as less serious. Such a pattern may also be derived from the socio-cultural differences. When Koreans are either dissapointed or delighted, they say frequently "I want to die" or "It's funny to death" and so on. This idiomatic expression is far from the real death wish but rather an expression of magnification. And the suicidal idea itself is frequently seen in normal population even suicidal attempt is evaluated as abnormal in Korea. With such reasons, Korean psychiatrists may notice suicidal idea as less serious than American psychiatrists. And the suspiciousness may be a way of living for the people under the historical turmoil and vigorous aculturation, that it is perceived as not so abnormal. The next problem is the marked discrepancy of opinion about abnormal behaviors among psychiatrists, physicians, herb practitioners and normal population samples. The agreement of physicians, herb practitioners, urban samples and rural samples with the psychiatrists on the relative severity of symptoms revealed as Spearman's rho of 0.79, 0.59, 0.58 and 0.44 respectively. It is the main point of problem that physicians are less aware of neurotic symptoms which can appear in the somatic illness, and of psychosomatic symptoms as psychiatric problem. Possible reason is that Korean physician have been oriented to the somatic medicine without proper psychosomatic orientation. On the other hand, the herb practitioners are apt to ignore the severity of psychotic symptoms and on the other, regard the neurotic and psychosomatic symptoms as much as psychiatrists' opinion. And the samples of normal population regard the neurotic symptoms as more serious than the psychotic symptoms, and are not aware of the psychosomatic symptoms as psychiatric problems. Physicians, herb practitioners and samples from the normal population underestimate the alcoholic behavior more than psychiatrists do. The alcoholism according to physicians' opinion is rather somatic problem than psychological one. The herb practitioners and adults from normal population manifest the prominently tolerable attitude toward alcoholic behavior. In conclusion, two kinds of problems can be suggested. One is that the difference between Korean and American psychiatrists in the evaluation on the severity of abnormal behaviors, is possibly due to sociocultural differences. The other is the intracultural difference among psychiatrists, physicians, herb practitioners and adults from normal population. Such a difference suggests that there is a considerable cultural lag in the disease concept and attitude between the modern psychiatry and the cultural tradition. This discrepancy can result in the undesirable wandering of patients for seeking the treatment and some hardship in modern psychiatric practitioning in Korea.