• Analytical Science and Technology
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• v.26 no.1
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• pp.91-98
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• 2013

Interested in NOA (Naturally Occurring Asbestos), Korea as well as the USA has been making geologic maps of asbestos distributed mines and surrounding areas, restoring mines, evaluating hazard, and so on. The result can be used to improve the reliability of analysts and analysis institutions by judging the amount of asbestos and set up PLM(Polarizing Light Microscope) information by analyzing in soil. The certification value of 2 kinds of CRM(Certified Reference Material) was performed by counting total 400 points with EPA 600-R-93-116 method using by PLM. The following is the result of homogeneity and stability of 2 kinds of manufactured CRM analyzed by ANOVA (Analysis of variance) and Regression Analysis. Based on the analyzation, the results are satisfied with homogeneity and long-term stability. The analyzed certification value of CRM includes the range of minimum and maximum value of point counting result for chrysotile; low concentration-1% (range, 0.25~3.00), high concentration-4% (range, 2.25~5.50).

• Applied Chemistry for Engineering
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• v.24 no.4
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• pp.370-374
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• 2013

The effects of zinc chloride addition on pore development of porous carbon nanofibers prepared by polyacrylonitrile (PAN)/ N,N'-dimethylformamide (DMF) (10 wt%) electrospinning were investigated. The change of morphological and structural modification by zinc chloride activation was investigated by a scanning electron microscopy (SEM) analysis. $N_2$ adsorption isotherm characteristics at 77 K were confirmed by Brunauer-Emmett-Teller (BET) and Horvath-Kawazoe (H-K) equations, and the curves showed the Type I mode in the International Union of Pore and Applied Chemistry (IUPAC) classification, indicating that lots of micropores exist in the sample. In addition, specific surface areas and total pore volumes of porous carbons prepared by the zinc chloride activation were determined as 600~980 $m^2/g$ and 0.24~0.40 $cm^3/g$, respectively. As experimental results, many holes or demolished structures were found on the fiber surfaces after the zinc chloride activation as confirmed by a SEM analysis. It was also observed that various pore sizes were found to be depended on the adding content of zinc chloride in PAN/DMF solution in this system.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.169-179
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• 2005

Acidic metavolcanic rocks distributed around the Chungju iron deposit show significantly high abundances of rare earth elements and high field strength elements. Relatively high ${\epsilon}_{Nd}$(0) values and lack of negative Nb anomaly suggest that assimilation of crustal material is not involved in their generation. They are plotted within the within-plate environment according the tectonic discrimination diagrams. Such geochemical characteristics are very similar to the acidic metavolcanic rocks of Munjuri Formation. They also show geochemical characteristics of Al-type magma of Eby (1992). All such diagnostic characters indicate differentiation of mantle-derived magma produced from the rift environment, related to the breakup of continent. In contrast to the alkali granites and the rare metal deposit both having age of c. 330 Ma, Sm-Nd isotopic data of the acidic metavolcanic rocks do not form well defined isochron. However, the alkali granites reveal low ${\epsilon}_{Nd}$(0) values, while the acidic metavolcanic rocks and the rare metal deposit both have significantly higher ${\epsilon}_{Nd}$(0) values. Considering such differences, we propose following generation hypothesis: The acidic metavolcanic rocks around Chungju iron deposit was erupted at 750 Ma as rest of the acidic metavolcanic rocks of Gyemyeongsan and Munjuri Formations. About 330 Ma ago, partial melting of existing Al-type igneous materials and some old crustal materials produced alkali granite. The rare metal deposit was also produced by redistribution of related materials within the acidic volcanics due to hydrothermal activities occurred at the same time. Sm-Nd isotopic systematics of the acidic metavolcanic rocks were disturbed during the regional metamorphic event at ca. 280 Ma.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.79-89
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• 1997

One of the strenuous problems in orthodontic procedures is postretention stability and retention against relapse. Many investigative trial had been done to disclose the factors associated with relapse and effective prescription to stave off, however, the nature of these jeopardies remained obscure. The objective was to investigate the long-term stability and quantitative changes of dental arches subsequently after Class I nonextraction treatment. Study models,cephalometric headfilms of 26 samples which were taken before, after teatment and postretention were employed to measure the interdental width of corresponding buccal teeth,overbite,overjet and the inclination of incisors and molars. Statistical analysis was carried to compare each measurements across the time period, and followings were brought around. 1. The quantitative amount of relapse in overbite presented positive correlation with the amount of changes through the treatment. 2. Stability of intercanine width was so far secure in the case the expansion had been done through. 3. The amount of changes in intercanine width of the lower regardless of expansion or contraction manifested less than the upper, however, the relapse ratio got high. 4. The upper and lower incisors were likely to be labioversive, and remained stable after retention. 5. The first molars of the upper and lower were conceivably tipped back immediately after treatment and returned to the original angulation. The expansion of intermolar width stayed stable across the time scheme after treatment It was suggested that the maintenance of intercanine width of lower was pertinent to perform the postretention stabilityv and the expansion of dental arch shoed be confined within physiologic boundaries of the patients.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.31-49
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• 2012

Satae cheon, a tributary of the Suip cheon in Yanggu, Gangwon province, is an international river extended to North Korea. Most of drainage basin area of the river was the fierce battle field during the Korean War(1950-1953) and hard to access as it located between the MDL(Military Demarcation Line) and the CCZ(Civilian Control Zone: about 10km south from MDL). By the restriction of access to the sites, most of natural landscape have been well conserved except limited use for military activities. Even the landfoms in that area were not studied, except the government's heritage reports. Satae Cheon's channel follows the Imdang fault line(N-S) to Satae-ri and flow to west to the Dutayeon area. The river meanders along geological structure or weak line at the Dutayeon area. The meandering channel was shorten by the meander cut which linked the thalweg line of meander loop ant the meander neck. As a result of this cut, the river cliff formed by the Satae cheon became the part of newly formed channel bed and the S-forms are formed. After the channel route stabilized, channel incised the rock with large potholes and undulating walls were formed. The channel width changes from 1m to 10m with restriction of the undulating walls, so this part can be regarded as inner channel or inner gorge. From the point of planar forms it also can be slot-type canyon.

• The Journal of Korean Philosophical History
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• no.38
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• pp.129-162
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• 2013

Noju Oh Hui-sang was a Confucian who was active during the reign of King Sunjo in late Joseon Dynasty and he also was a master of the Sallim faction. Though he is known as an eclectic Neo-Confucian, he had profound knowledge in the study of Confucian classics as well through succeeding the family study handed down by his father Oh Jae-sun and his oldest brother Oh Yun-sang. This thesis hereby examines Noju's Confucianism doctrine and its characteristics. Noju's Confucianism doctrine is characterized significantly with the following aspects. First, its analyses are detailed overall and it annotates chapters and verses mostly related to Neo-Confucian theories on interpretation of the Confucian classics. Second, it conducts in-depth study not only on Chu Hsi's annotation but also on the small commentaries (小注) in Compendium of the Commentaries on Four Chinese Classics (四書集註大全). In terms of Chu Hsi's theory, however, Noju interprets Confucian classics while supplementing shortcomings on Chu Hsi's theory rather than opposing it. For opinions of all philosophers and scholars on small commentaries, it expresses rather critical theories than supporting ones. Third, it quotes many theories not only of Chinese Confucians but also of Korean ones. It mainly introduces theories of Namdang Han Won-jin, including those of Yi Yulgok. Among them, it particularly has frequent quotations from Han Won-jin's Kyoungyigimunrok (經義記聞錄). Fourth, Noju actively acknowledges senior Confucians' theories many times in quoting them but he also daringly points out their errors when a theory is thought not to be appropriate. He indicates errors one by one in theories not only of Uam and Yulgok but even of Mencius. Fifth, it especially discusses Book of Changes (周易) in depth. It tends to criticize Chengzi's I-Chuan (易傳) but accept Chu Hsi's Benyi (本義). It roughly explains Book of Changes in general but seldom directly accounts for trigrams of it other than Qian trigram and it has detailed explanation especially on Xicizhuan (繫辭傳).

• Applied Microscopy
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• v.35 no.1
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• pp.31-39
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• 2005

Synapses are contact points where one neuron communicates with another. The morphological change of synapses under various physiological or pathological conditions has long been hypothesized to modify their functional properties. 3-dimensional (3-D) reconstruction of synapses with serial ultrathin sections has contributed to the understanding of ultrastructural dimensions and compositions of synapses. The 3-D reconstruction procedures, however, require a great amount of expertise as well as include prohibitively timeconsuming processes. Here, we introduce efficient 3-D reconstruction technique using high-voltage electron microscopy (HVEM). Primarily, we established an optimal section thickness and staining condition to observe synaptic structures in detail under HVEM. The result showed that synaptic profiles were preserved at the section thickness of 250 nm without the overlapping of synaptic ultrastructures. An increase in the reaction time of en bloc staining was most efficient to enhance contrast than the extension of postembedding staining or the addition of uranyl acetate during dehydration. Then, 3-D reconstruction of parallel fiber-Purkinje cell synapses in the rat cerebellum was carried out with serial HVEM images and reconstruction software. The images were aligned and the contours of synapses were outlined on each section. 3-D synapses were finally extracted from the section files by grouping all the synaptic contours. The reconstructed synapse model clearly demonstrated the configuration of pre and postsynaptic components. These results suggest that 3-D reconstruction of synapses using HVEM is much efficient and suitable for massive quantitative studies on synaptic connectivity than conventional TEM approach using numerous ultrathin sections.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.13.2-14
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• 1982

Otitis media with effusion, described first by Politzer (1867), is closely related with the function of auditory tube, but its etiology and pathogenesis are not clearly defined yet. There are many theories about its pathogenesis including hydrops ex vacuo theory which was most reliable nowadays. In this paper, using cats in experimental animals, hydrops ex vacuo theory was proved and cytological study of the effusion and light microscopic observation of the middle ear mucosa in otitis media with effusion were done. The results were as follows: 1) The effusion was found in all experimental groups after eighteen hours of the auditory tube obstruction. 2) In the cytological study of effusion by smear technic, Polymorpholeukocytes were dominant in earlier days but monoculear cells were soon increased and no eosinophils were found. 3) In the culture of the effusion, no bacteria was cultured. 4) By opeating microscope, hypertrophy of the middle ear mucosa observed especially in the fourteen days after auditory tube obstruction and effusion was most remarkable in the fourteen days, also. 5) By light microscopy, there were epithelial hyperplasia, proliferation of goblet cells, capillaries and infiltration of inflammatory cells which showed same distribution as smear technic.

• Tuberculosis and Respiratory Diseases
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• v.49 no.3
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• pp.353-364
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• 2000

Background : Bronchoscopy is a useful diagnostic tool, for accurate localization of the bleeding site and the management of hemoptysis. However, there is some controversy about the optimal timing of bronchoscopy. Method : To determine the optimal timing of bronchoscopy in hemoptysis, we reviewed the medical records of 118 patients and analyzed the following relationships amongst simple chest PA findings, namely, the duration and amount of hemoptysis, and the timing of bronchoscopy retrospectively. Results : The major causes of hemoptysis were active tuberculosis(28.8%), inactive tuberculosis(10.2%), bronchiectasis(17.0%), lung cancer(7.6%), and aspergilloma(7.6%). Localization of the bleeding focus by bronchoscopy was possible in 87.5% (21/24 cases) during active bleeding, and it was possible in 40.4% after bleeding had stopped(p<0.05). The localization rate of bleeding focus was 59.8% when the chest PA showed certain abnormalities, but it decreased to 27.8% when the chest PA finding was normal(p<0.05). When chest PA showed diffuse abnormalities or its finding was normal, the localization rate of bleeding focus significantly increased if bronchoscopy was performed during bleeding or within 48 hours of the cessation of active bleeding. The localization rate was higher as the amount of hemoptysis became larger(p<0.05). The localization rate of early bronchoscopy(during bleeding or within 48 hours of the cessation of active bleeding) was significantly higher when the duration of hemoptysis was less than 1 week, but there was no advantage if the duration was 1 week or longer. Early bronchoscopy was also necessary to localize the bleeding focus for surgical resection in 4 patients, and the bronchoscopy itself was therapeutic in 1 patient whose bleeding was successfully managed with thrombin-application via bronchoscope. Conclusion : It is concluded that flexible bronchoscopy is useful at not only localizing the bleeding focus but also in preparing a therapeutic plan, and early bronchoscopy is more favorable in hemoptysis.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.310-317
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• 2015

Purpose: The purpose of this study was to evaluate the validity of reference points for edentulous patient by examining the correlation of teeth and face, and intraoral anatomic landmarks. Materials and methods: We examined a facial outline, length, bizygomatic width, nasion - gnathion length, glabella - nasion distance in 270 men and 280 women satisfied with inclusion criteria from Seoul National School of Dentistry. The shape of maxillary central incisor, mesiodistal crown width and length of maxillary 6 incisors, distance from incisive papilla to labial surface of maxillary central incisor, and perpendicular distance from incisive papilla to intercanine line were measured in the stone model. We analyzed the ratio and relevant relation statistically. Results: The probability on having the same shape of face and the relative same shape maxillary incisor was 55.56% and 46.43% for men and women. The facial length proved to be a more valuable measurement in women in the tooth selection. The ratio of bizygomatic width to mesiodistal width of maxillary central incisor, and the ratio of bizygomatic width to width of maxillary 6 incisors were 16.8 : 1 and 3.0 : 1 and were positively correlated with each other. The distance of the canines from the maxillary incisal papilla was $1.33{\pm}1.28mm$. The distance between the center of the incisal papilla and the labial surface of their maxillary central incisor was $9.23{\pm}1.20mm$. Conclusion: It was showed that anatomical reference points in tooth selection and arrangement for edentulous patient are useful and have validity in our limited study.