• Economic and Environmental Geology
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• v.30 no.4
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• pp.303-312
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• 1997

The massive, fractured and porous-type of glauconite, which is subdivided by surface morphology, occur in subtidal sand and semiconsolidated intertidal sand/mud from continental shelf of the southeastern Yellow Sea. This area is presumed to be a part of Holocene transgressive tidal systems tract. The glauconite, pellet-like grains with diameter of 0.1 to 1 mm, is scattered in surface sand sediments. Results of X-ray diffraction data of the minerals are monoclinic with $a=5.242{\AA}$, $b=9.059{\AA}$, $c=10.163{\AA}$, ${\beta}=100.5^{\circ}$, $V=474.53{\AA}^3$. Thermal treatments on the oriented glauconite increase the X-ray diffraction intensity near $10{\AA}$ (001), suggesting the presence of some expandable layers. Specific gravity of the glauconite is $2.60{\pm}0.45gm/cc$ on the basis of chemical composition and unit-cell dimensions. Based on $O_{10}(OH)_2$, chemical composition of glauconites, octahedral Fe content ranges from 1.19 to 2.06 atoms, corresponding octahedral AI is 0.18 to 0.76 atoms, which progressively substitute Fe for AI with increasing from porous to massive-type. The Mg content ranges from 0.35 to 0.54 atoms, and shows higher with increasing Al contents. A systematic increase of interlayer K from 0.34 to 0.71 is also observed with apparent increases from porous to massive-type, and related to a proportion of expandable layers. The clay preserved in glauconite, which is recognized as ordered/disordered (massive to fractured-type). The interstratified illite/smectite (porous-type), contains 7 to 27 % expandable layers. The glauconite seems to originate from post depositional authigenic growth in reducing environments promoted by the dissolution of clay minerals and biogenic debris.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.102-110
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• 2007

The purpose of this study was to obtain the basic information for the improvement of dental environment by investigating the presence of methicillin- or vancomycin-resistant Staphylococcus aureus (MRSA or VRSA) isolated from dental health care workers (DHCWs) and environment of the Chosun University Dental Hospital (CUDH) and a private dental clinic (control group). Staphylococcus aureus (S. aureus) was isolated from anterior nares of 42 DHCWS and 38 sites, unit chairss, x-ray devices, computers, etc., at 10 departments of the CUDH and 20 DHCWs and 11 sites at the private dental clinic. S. aureus was isolated on mannitol salt agar plate and confirmed by PCR with S. aureus species-specific primer. Antimicrobial susceptibility test of clinical isolates of S. aureus against several antibiotics including methicillin (oxacillin) was performed by investigating minimum inhibitory concentration (MIC) using broth microdilution assay. In addition, PCR was performed to detect the methicillin- or vancomycin-resistant gene. The data showed that one strain of S. aureus was isolated from DHCWs of the CUDH and three strains of S. aureus was isolated from 3 samples of the private dental clinic, respectively. All of the isolates from the CUDH and the private dental clinic had resistance to penicillin G, amoxicillin and vancomycin and susceptibility to oxacillin and ciprofloxacin. The S. aureus strains were already obtained the resistance to penicillin G and amoxicillin. These results suggest that two dental clinics were under relatively safe environment.

• Journal of the Korean Society of Food Culture
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• v.5 no.1
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• pp.59-75
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• 1990

The tzeam is the one of steaming cook that boiled the main material of poultry. meat and the sub-material of vegetables. It is always setted on the main-table in above seven chup ban sang and also kyoja sang. In this thesis, according to the kinds of tzeam in the main material of poultry, meat was to analysis reference frequency to them the materials, the measuring unit of materials, the terms of cooking and kitchen utensil by 47 books published in Korea from 1420 to 1987. 1. It was 37 kinds of tzeam in the main material of poultry, meat. 2. Materials were classified into the main-material, sub-materials, seasioning and decorations. 3. There were 43 kinds of measuring units, of them 18 kinds were for volume, 12 kinds were for quantity, 4 kinds were for length and the rest measuring units were 9 kinds. 4. There were 26 kinds of kitchen utensil for cooking. They were mainly used a hab 1 rice ball with lids, and castles (cast iron castle). 5. There were 27 kinds of cooking terms. The terms of them, 11 kinds were for heating methods, 16 terms of them were for the cutting process.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.634-643
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• 2005

The aim of this study is to evaluate the effects of blue light emitting diode (LED) Light Curing Units (FreeLight 2, L.E.Demetron I, Ultra-Lume 5) on the microhardness of three resin composites (Z250, Point 4, Dyract AP) and to determine their optimal curing time. Samples were made using acrylic molds $(2.0mm{\times}3mm)$ of each composite. All samples were prepared over a Mylar strip placed on a flat glass surface. After composite placement on the molds, the top surface was covered with another Mylar strip and a glass slab was gently pressed over it. The times of irradiation were as follows: Elipar TriLight, 40 s; Elipar FreeLight 2. L.E.Demetron I, and Ultra-Lume 5, 10s, 20s, 40s, respectively. Mean hardness values were calculated at the top and bottom for each group. ANOVA and Sheffe's test were used to evaluate the statistical significance of the results. Results showed that FreeLight 2, Ultra-Lume 5, and L.E.Demetron I were able to polymerize point 4 in 20 seconds to a degree equal to that of the halogen control at 40 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Z250 in 10 seconds to a degree equal to that of the halogen control at 20 seconds. FreeLight 2 and L.E.Demetron I were able to polymerize Dyract AP in 10 seconds to a degree equal to that of the halogen control at 40 seconds. The commercially available LED curing lights used in this study showed an adequate microhardness with less than half of the exposure time of a halogen curing unit.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.4
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• pp.243-252
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• 2006

Influence of the increasing carbon dioxide concentration in seawater on various marine organisms is assessed in this article with regard to the impacts of anthropogenic $CO_2$ introduced into surface or deep oceans. Recent proposals to sequester $CO_2$ in deep oceans arouse the concerns of adverse effects of increased $CO_2$ concentration on deep-sea organisms. Atmospheric introduction of $CO_2$ into the ocean can also acidify the surface water, thereby the population of some sensitive organisms including coral reefs, cocolithophorids and sea urchins will be reduced considerably in near future (e.g. in 2100 unless the increasing trend of $CO_2$ emission is actively regulated). We exposed bioluminescent bacteria and benthic amphipods to varying concentrations of $CO_2$ and also pH for a short period. The ${\sim}l.5$ unit decrease of pH adversely affected test organisms. However, amphipods were not influenced by decreasing pH when HCl was used for the seawater acidification. In this article, we reviewed the biological adverse effects of $CO_2$ on various marine organisms studied so for. Theses results will be useful to predict the potential risks of the increase of $CO_2$ concentrations in seawater due to the increase of atmospheric $CO_2$ emission and/or sequestration of $CO_2$ in deep oceans.

• Radiation Oncology Journal
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• v.18 no.4
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• pp.244-250
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• 2000

Purpose : To see the relationship between the response to chemotherapy and the final outcome of neoadiuvant chemotherapy and radiotherapy in patients with mocanry advanced hypopharyngeal cancer. Methods and Materials :A retrospective analysis was done for thirty-two patients with locally advanced hypopharyngeal cancer treated in the Seoul National University Hospital with neoadiuvant chemotherapy and radiotherapy from August 1979 to July 1997. The patients were treated with Co-60 teletherapy unit or 4MV or 6MV photon beam produced by linear accelerator. Daily fractionation was 1.75 to 2 Gy, delivered five times a week. Total dose ranged from 60.8 Gy to 73.8 Gy. Twenty-nine patients received continuous infusion of cisplatin and 5-FU. Other patients were treated with cisplatin combined with bleomycin or vinblastin. Twenty-four (75$\%$) patients received all three prescribed cycles of chemotherapy delivered three weeks apart. Six patients received two cycles, and two patients received only one cycle. Results :The overall 2-year and 5-year survival rates are 65.6$\%$ and 43.0$\%$, respectively. 5-year local control rate is 34$\%$. Organ preservation for more than five years is achieved in 12 patients (38$\%$). After neoadjuvant chemotherapy, 24 patients achieved more than partial remission (PR): the response rate was 75$\%$ (24/32). Five patients had complete remission (CR), 19 patients PR, and 8 patients no response (NR). Among the 19 patients who had PR to chemotherapy, 8 patients achieved CR after radiotherapy. Among the 8 non-responders to chemotherapy, 2 patients achieved CR, and 6 patients achieved PR after radiotherapy. There was no non-responder after radiotherapy. The overall survival rates were 60$\%$ for CR to chemotherapy group, 35.1$\%$ for PR to chemotherapy group, and 50$\%$ for NR to chemotherapy group, respectively (p=0.93). There were significant difference in five-year overall survival rates between the patients with CR and PR after neoadjuvant chemotherapy and radiotherapy (73.3$\%$ vs. 14.7$\%$, p<0.01). The prognostic factor affecting overall survival was the response to overall treatment (CR vs. PR, p<0.01). Conclusion :In this study, there were only five patients who achieved CR after neoadiuvant chemotherapy. Therefore the difference of overall survival rates between CR and PR to chemotherapy group was not statistically significant. Only the response to chemo-radiotherapy was the most important prognostic factor. There needs to be more effort to improve CR rate of neoadjuvant chemotherapy and consideration for future use of concurrent chemoradiotherapy.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.663-674
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• 2019

Birds are effective ecological indicators but there is no national protocol in place to monitor population dynamics of forest birds in Korea. To support the establishment of future monitoring protocols, we compared the results of two generally used monitoring methods for forest bird surveys in two temperate mixed forests in central Korea. There was no statistical difference in the number of species and individuals detected per unit survey effort when comparing line transects and point counts. The number of species and individuals were higher in a five-minute count than in a three-minute point count, but the total accumulated number of expected observed species showed no difference between the two count durations. The number of observed species and individuals increased in both methods as plot radius or transect width increased, suggesting that multi-layer or multi-band surveys may be useful for quantitative and qualitative objectives. The decreasing number of observed species and individuals after sunrise suggested that bird monitoring should be conducted earlier in the morning, within four hours after sunrise. To detect 70% of the total number of species, 7.0 to 7.6 survey hours, equivalent to 42 three-minute counts (95% confidence interval [CI]: 26 to 61) or 33 five-minute counts (95% CI: 19 to 53) were needed for unlimited radius point counts. On the other hand, 4.8 survey hours, equivalent to 26 line transect counts (95% CI: 15 to 45) using 200-m transects with unlimited width, were required to achieve the same level of species detection. Therefore, the line transect method may be more effective than the point count method, at least in terms of local species richness assessment. For national forest bird monitoring, our data indicated that one or both survey methods can be selected as a basic protocol, based on the goals and scales of monitoring, forest types, and the conditions of the target areas.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.125-133
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• 1995

The crystal structure of dehydrated, partially Co(II)-exchanged zeolite X, stoichiometry Co2+Na+-X (Co41+Na10Si100Al92O384) per unit cell, has been determined from three-dimensional X-ray diffraction data gathered by counter methods. The structure was solved and refined in the cubic space group Fd3:α=24.544(1)Å at 21(1)℃. The crystal was prepared by ion exchange in a flowing stream using a solution 0.025 M each in Co(NO3)2 and Co(O2CCH3)2. The crystal was then dehydrated at 380℃ and 2×10-6 Torr for two days. The structure was refined to the final error indices, R1=0.059 and R2=0.046 with 211 reflections for which I > 3σ(I). Co2+ ions and Na+ ions are located at the four different crystallographic sites. Co2+ ions are located at two different sites of high occupancies. Sixteen Co2+ ions are located at the center of the double six-ring (site I; Co-O = 2.21(1)Å, O-Co-O = 90.0(4)°) and twenty-five Co2+ ions are located at site II in the supercage. Twenty-five Co2+ ions are recessed 0.09Å into the supercage from its three oxygen plane (Co-O = 2.05(1)Å, O-Co-O = 119.8(7)°). Na+ ions are located at two different sites of occupandies. Seven Na+ ions are located at site II in the supercage (Na-O = 2.29(1)Å, O-Na-O = 102(1)°). Three Na+ ions are statistically distribyted over site III, a 48-fold equipoint in the supercages on twofold axes (Na-O = 2.59(10)Å, O-Na-O = 69.0(3)°). Seven Na+ ions are recessed 1.02Å into the supercage from the three oxygen plane. It appears that Co2+ ions prefer sites I and II in order, and that Na+ ions occupy the remaining sites, II and III.

• Neonatal Medicine
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• v.15 no.1
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• pp.67-74
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• 2008

Purpose : The purpose of this study was to assess the natural history and perinatal outcomes of twin gestations according to chorionicity. Methods : We retrospectively reviewed the medical records of 99 monochorionic (MC) and 206 dichorionic (DC) twin gestations delivered at Il Sin Christian Hospital in Busan between January 2002 and December 2007. The incidences of twin-to-twin transfusion syndrome (TTS) and selective intrauterine growth restriction (sIUGR), as well as perinatal morbidity and mortality, were evaluated. Results : MC twins had a lower gestational age (35.7 vs. 36.6 weeks, P=0.03) at birth and a higher incidence of intrauterine fetal loss (10% vs. 1.5%, P<0.001) than DC twins. The incidence of intrauterine fetal loss was higher in MC sIUGR than in DC sIUGR (19% vs. 2.5%, P=0.025) twins. The number of admissions to the neonatal intensive care unit (NICU; 31% vs. 16%, P=0.042), and the incidence of periventricular leukomalacia (7% vs. 0%, P=0.031), and respiratory distress syndrome with surfactant treatment (27% vs. 11%, P=0.049) were higher in MC than DC twins. The incidences of sIUGR and TTS were 21 and 9% among the MC twins. The incidences of intrauterine fetal loss were higher in MC twins with TTS [6 of 9 (67%)] or sIUGR [4 of 21 (19%)] than uncomplicated MC twins (P<0.001). The frequency of admission to the NICU (P=0.001), the length of hospital stay (P=0.033), the prevalence of periventricular leukomalacia (P=0.011), and intraventricular hemorrhage (P=0.007) were also higher in MC with TTS or sIUGR than in uncomplicated MC twins. Conclusion : The incidence of neonatal complications was higher in MC twins, especially those gestations complicated by TTS or sIUGR.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.804-811
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• 2010

The lower portion of sloping paddy fields normally contains excessive moisture and the higher water table caused by the inflow of ground water from the upper part of the field resulting in non-uniform water content distribution. Four drainage methods namely Open Ditch, Vinyl Barrier, Pipe Drainage and Tube Bundle for multiple land use were installed within 1-m position from the lower edge of the upper embankment of sloping alluvial paddy fields. Knowledge of the spatial variability of soil water properties is of primary importance for management of agricultural lands. This study was conducted to evaluate the effect of drainage in the soil on spatial variability of soil water content using the geostatistical analysis. The soil water content was collected by a TDR (Time Domain Reflectometry) sensor after the installation of subsurface drainage on regular square grid of 80 m at 20 m paddy field located at Oesan-ri, Buk-myeon, Changwon-si in alluvial slopping paddy fields ($35^{\circ}22^{\prime}$ N, $128^{\circ}35^{\prime}$). In order to obtain the most accurate field information, the sampling grid was divided 3 m by 3 m unit mesh by four drainage types. The results showed that spatial variance of soil water content by subsurface drainage was reduced, though yield of soybean showed the same trends. Value of "sill" of soil water content with semivariogram was 9.7 in Pipe Drainage, 86.2 in Open Ditch, and 66.8 in Vinyl Barrier and 15.7 in Tube Bundle.