• Economic and Environmental Geology
• /
• v.30 no.3
• /
• pp.249-262
• /
• 1997

The Sr and Nd isotopic compositions of two foliated granitic plutons located in the Chonju and Sunchang area were determined in order to reconfirm the intrusion ages of granitoids and to study the sources of granitic magmas. The best defined Rb-Sr isochron for the whole rock samples of the Chonju foliated granite (CFGR) give an age of $284{\pm}12Ma$, suggesting early Permian intrusion age. In contrast, the whole rock Rb-Sr data of the Sunchang foliated granite (SFGR) scatter widely on the isochron diagram with very little variation in the $^{87}Rb/^{86}Sr$ ratios and, therefore, yield no reliable age information. Futhermore they show the concordance of mineral and whole rock Rb-Sr isochron and divide into two linear groups with roughly the same slopes and significantly different $^{87}Sr/^{86}Sr$ ratios, indicating some kind of Rb-Sr distortion in whole rock scale and a difference in source material and/or magmatic evolution between two subsets. The reconstructed isochrons of 243 Ma, which was defined from the proposed data by the omission of one sample point with significantly higher $^{87}Rb/^{86}Sr$ ratio than the others, and 252 Ma, from the combined data of it and some of this study, strongly suggest the possibility that the SFGR was intruded appreciably earlier than had previously been proposed, although the reliability of these ages still questionable owing to high scatter of data points and, therefore, further study is necessary. All mineral isochrons for the investigated granites show the Jurassic to early Cretaceous thermal episode ranging from 160 Ma to 120 Ma Their corresponding initial $^{87}Sr/^{86}Sr$ ratios correlate well with their whole rock data, indicating that the mineral Rb-Sr system of the investigated granites was redistributed by the postmagmatic thermal event during Jurassic to early Cretaceous. The initial ${\varepsilon}Sr$ values for the CFGR (64.27 to 94.81) tend to be significantly lower than those for the SFGR (125.43 to 167.09). Thus it is likely that there is a marked difference in the magma source characteristics between the CFGR and the SFGR, although the possibility of an isotopic resetting event giving rise to a high apparent initial ${\varepsilon}Sr$ in the SFGR can not be ruled out. In contrast to ${\varepsilon}Sr$, both batholiths show a highly resticted and negative values of initial ${\varepsilon}Nd$, which is -14.73 to -19.53 with an average $-16.13{\pm}1.47$ in the CFGR and -14.78 to -18.59 with an average $-17.17{\pm}1.01$ in the SFGR. The highly negative initial ${\varepsilon}Nd$ values in the investigated granitoids strongly suggest that large amounts of recycled old continental components have taken part in their evolution. Furthermore, this highly resticted variation in ${\varepsilon}Nd$ is significant because it requires that the old crustal source material, from which the granitoid-producing melts were generated, should have a reasonably uniform Nd isotopic composition and also quit similar age. Calculated T2DM model ages give an average of $1.83{\pm}0.25Ga$ for CFGR and $1.96{\pm}0.19Ga$ for SFGR, suggesting the importance of a mid-Proterozoic episode for the genesis of two foliated granites. Although it is not possible to determine precisely the source rock compositions for the investigated foliatic granites, the Sr-Nd isotopic evidences indicate that midcrustal or less probably, a lower crustal granulitic source could be the most likely candidate.

• Economic and Environmental Geology
• /
• v.42 no.4
• /
• pp.289-300
• /
• 2009

The Geodo mine area, had been developed for Fe and Cu ores since 1963 and abandoned in recent decades, is located in the central part of the Taebaeksan mineralized district. This area comprises of the Jangsan, Myobong, Pungchon, Hwajeol, Dongjeom, and Dumugol Formations in ascending stratigraphic order. These Formations were intruded by the Cretaceous Eopyeong granitoids that appears to produce the Geodo skarn. Their compositions are relatively oxidized quartz monzodiorite to granodiorite (magnetite series, $Fe_2O_3/FeO=0.3{\sim}1.1$). Mineralizations related skarn deposit occur in the Myobong, Pungchon, and Hwajeol Formations. The proximal skarn is zoned from andraditic garnet ($Ad_{44-95}Gr_{1-53}$) predominant adjacent to the Eopyeong granitoids to diopsidic pyroxene ($Hd_{10-100}Di_{0-89}$) predominant away from the one. The differential proportion of garnet and pyroxene is generated by water/rock ratio and their source, such as magmatic and meteoric water. This is useful tool for assessment the overall oxidation state of the entire skarn system. Gold occurs in proximal red to brownish garnet skarn, and genetically associated with Bi- and Te-bearing minerals. Skarn deposit developed in the Geodo mine area is considered as oxidized Au skarn category, based on chemical composition of the Eopyeong granitoids, zonation of skarn, and gold occurrences. Garnet-rich skarn zone will be the main target for exploration of gold in the study area. However, it is needed to the detailed survey on vertical zonation of this area as well as lateral zonation. The result of this survey would provide an important basis for the exploration of the skarn Au deposit in the Geodo mine area.

• Applied Chemistry for Engineering
• /
• v.17 no.3
• /
• pp.243-249
• /
• 2006

Porous polymer gel electrolytes (PGEs) based on poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) as a polymer matrix and polyvinylpyrolidone (PVP) as a pore-forming agent were prepared and electrochemical properties were investigated for an electric double layer capacitor (EDLC) in order to increase a permeability of an electrolyte into the PGE. Propylene carbonate (PC) and ethylene carbonate (EC) as plasticizers, and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a supporting salt for the PGE were used. EDLC unit cells were assembled with the PGE and electrode comprising BP-20 and MSP-20 as activated carbon powders, Super P as a conducting agent, and P(VdF-co-HFP)/PVP as a mixed binder. Ion conductivity of PGEs increased with an increased PVP content and was the best at 7 wt% PVP, whereas electrochemical characteristics such as AC-ESR of unit cell were better in 3 wt%. And electrochemical characteristics of the unit cell with PGE were the best at a 33 : 33 weight ratio of PC to EC. Specific capacitance of a mixed plasticizer system of PE and EC was higher than that of pure PC. Ion conductivity of PGEs with a film thickness of $20{\mu}m$ was higher, but electrochemical characteristics of unit cells were higher for a $50{\mu}m$ membrane thickness. Also, the unit cell has shown the highest capacitance of 31.41 F/g and more stable electrochemical performance when PGE and electrode were hot pressed. Consequently, the optimum composition ratio of PGE for EDLCs was 23 : 66 : 11 wt% such as P(VdF-co-HFP) : PVP = 20 : 3 wt% and PC : EC = 44 : 22 wt%. In this case, $3.17{\times}10^{-3}S/cm$ of ion conductivity was achieved at the $50{\mu}m$ thickness of PGE for EDLCs. And the electrochemical characteristics of unit cells were $2.69{\Omega}$ of DC-ESR, 28 F/g of specific capacitance, and 100% of coulombic efficiency.

• Korean Journal of Ecology and Environment
• /
• v.49 no.1
• /
• pp.11-21
• /
• 2016

Cymbidium kanran Makino is being threatened in its own habitats due illegal collecting and habitat changes by vegetation growth along historical landuse change. In this study, we established habitat restoration model for conservation of C. kanran based on ecological diagnosis. Through exploration to Jeju Island in 2014 and 2015, we identified 27 unknown habitats of C. kanran and in there, abiotic variables and vegetation structure and composition were quantified. Altitudinal distribution of C. kanran was between 200 m~700 m a.s.l. and compared to distribution in 2004, Area of Occupation (AOO) decreased at 82%. Specific habitat affinity was not observed by evenly found in mountain slope and valley and summergreen and evergreen broadleaved forests, but likely more abundant in valley habitats with higher soil and ambient moisture. Total of 96 individual of C. kanran was observed with an average density of $942.6individuals\;ha^{-1}$. The plants showed relatively short leaf length (average=$10.7cm{\pm}1.1cm$) and small number of pseudo bulbs ($1.2{\pm}0.2$). Flowering and fruiting individuals were not observed in field. C. kanran was classified into endangered plant species as CR (Critically Endangered) category by IUCN criteria. Phenotypic plasticity of C. kanran was likely support to sustain in more shaded habitat environment and recent habatat changes to closed canopy and low light availability may exhibit negatively effects to C. kanran's life history. Restoring C. kanran habitat should create open environment as grassland and low woody species density.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.29 no.1
• /
• pp.73-82
• /
• 2009

The experiment was carried out from January through December in 2008 at Chungnam National University and the Unbong Animal Genetic Resources Station, NIAS. The experimental animals were twelve dairy goats (female, $30{\pm}1.8kg$), twelve Korean native Boats(female, $24{\pm}2.4kg$) and five sika deer(female, $92{\pm}5.2kg$). A total of 11 different types of hay and straw were tested in this study: such straw imported from USA in 2006 as annual ryegrass, perennial ryegrass, tall fescue and Kentucky bluegrass, and such hay imported from USA in 2007 as alfatfa, bermudagrass, timothy, kleingrass, oat and orchardgrass, and such domestic hay as mixed hay There were significant differences in chemical composition and in vitro dry matter digestibility (IVDMD) among the various types of imported hay and straw (p<0.05). Besides alfalfa hay and orchardpass hay all of the imported hay contained lower crude protein (CP) and IVDMD but contained higher neutral detergent fiber(NDF) and acid detergent fiber (ADF) than the domestic hay. According to the kinds of the imported hay, relative feed value (RFV) made the difference and the hay grades were ranged from 4 to 5, based on the RFV. According to the kinds of the imported hay, there were markedly differences in dry matte. (DM) intake and palatability ranking among dairy goats, Korean native goats, and sika deer. DM intake and palatability ranking were high in common between orchardgrass hay and bermudagrass hay, but Kentucky bluegrass straw, tall fescue straw, perennial ryegrass straw and annual ryegrass straw were proved to be very low in DM intake and palatability ranking. In conclusion, the quality and palatability among the imported hay that was tested in the study were quite variable and lower than expected. It is required to establish a better feed evaluation system for the imported hay.

• Journal of Embryo Transfer
• /
• v.21 no.2
• /
• pp.157-162
• /
• 2006

It is well known that unidentified factors in sera, hormones and growth factors promote the proliferation of granulosa cells and nuclear maturation of bovine COCs (cumulus oocytes complexes) in vitro. Attempts had been developed the simple composition of culture media and similar system to in vivo conditions has been applied. In the present study, we investigated the effect of FGF (fibroblast growth factor) on in vitro maturation and in vitro development of Hanwoo COCs. When the COCs were matured in HPM 199 (Inst. of Functional peptide, Japan) containing 0.1, 1 and 10 ng/ml FGF for 24 hr, maturation rates to metaphase II ($70.0{\sim}75.0%$) were significantly higher (p<0.05) than that of control group (0 ng/ml FGF, 37.5%). When matured COCs with FGF were cultured in maturation medium after in vitro fertilization, developmental rates to blastocysts were 9.5, 0 and 2.9%, respectively, compared to 25.0% of the control group (p<0.05). When the matured COCs with FGF were cultured in HPM 199 (IFP971, Inst. of Functional peptide, Japan) containing 10% FBS, 0.8% BSA or 0.1% PVA (polyvinyl alcohol), the blastocyst formation rates were 12.4, 12.8 and 8.5%, respectively, while the rates of matured COCs with FGF and cultured with IVMD and IVD (Inst. of Functional peptide, Japan) without serum were 38.4% and 34.8%, respectively (p<0.05). These results suggested that FGF is available for in vitro maturation of bovine COCs and is not suitable for in vitro development, but further investigation would be need for finding the synergistic autocrine/paracrine fashion of other growth factors in early bovine embryo development.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.2
• /
• pp.321-331
• /
• 2005

The purpose of this study was to compare the effectiveness of mechanical and acid treatment on enamel surfaces for the retention of pit and fissure sealants and evaluate the presence of a prismless layer. The etch pattern produced on enamel from immature and mature premolar teeth extracted with varying period of acid etching using 37% phosphoric acid was examined using a scanning electron microscope(SEM). The composition of each groups was evaluated using an energy dispersive x-ray(EDX) spectroscopy. The result of present study can be summarized as follows: 1. Prismless layer was commonly observed on the fissure enamel in young and mature premolar. 2. There were no differences in micro-structure and etching pattern on fissure enamel between the young and the mature premolar. 3. The most effective etching pattern for retention of pit and fissure sealant was observed in 60 seconds of etching time and no apparent difference of etching pattern was found among 15, 30, and 45 seconds of etching time which showed non-retentive etching patterns. 4. The etching pattern obtained by grinding enamel surface with bur followed by 60 seconds of etching was similar to that of 60 seconds of etching without any pretreatment of fissure surface. 5. Type 2 etching pattern was commonly found on fissure enamel in both young and mature premolar. 6. The calcium content and P/Ca ratio in fissure enamel between the young and the mature premolar were significantly different(P<0.05). But content of calcium, phosphate and P/Ca ratio on various regions of fissure enamel in both young and mature premolar did not showed any difference. Based on these results, prismless layer may negatively influence the retention of pit and fissure sealants. Therefore, the mechanical removal of the prismless layer by grinding prior to etching or by prolonged etching time of enamel within the fissure system should result in an improved bonding of a pit and fissure sealant.

• Journal of Fisheries and Marine Sciences Education
• /
• v.23 no.3
• /
• pp.410-424
• /
• 2011

This study was investigated for the purpose of obtaining basic data which can be applied to processing of canned sea mussel using tomato paste. Shell were washed, and then steamed and shucked. Sea mussel meat was prepared with ratio of sea mussel 90g, tomato paste sauce 65g(tomato paste 42%, gum guar 1.0%, salt 2.0%, starch syrup 2.0%, cooking wine 1%, water 52%). The sea mussel meats were packed with vacuum seamer in 301-3 can, and then sterilized for various F0 value(F0 8-12 min.) in a steam system retort at $118^{\circ}C$. The factors such as pH, VBN, amino-N, total amino acid, free amino acid, chemical composition, color value (L, a, b), texture profile, TBA value, mineral, sensory evaluation and viable bacterial count of the canned sea mussel produced with various sterilization condition(F0 8-12 min.) were measured. The same element was also measured during preservation. The results showed that the product sterilized at F0 8 min. and preserved for 90 days were the most desirable.

• Resources Recycling
• /
• v.5 no.4
• /
• pp.32-41
• /
• 1996

The objective of this study was to investigate the facton affecting the property of CaCO, farmed from CaClz-Na,CO,-HiOsystem. The effcct of the concentmtlon of reaclants, impurity, the pH of reaction, the addition of sccd crystal, and injectingvelocity af reaclant solution an thc yield oI CaCO; polymorphs. parlide size and whiteness of CaCO, were investigated. Thcmqor resulls are ;o fallows; I The optimum concentratinn of reildilnts for forming vaterlte and aragonite is the range of 0.1-1.0 mol/l, when the yicld of vittcrite and araga~nles howed 7542% and XU-90%. respedively. 2. Among thc composition of impunticscontained h limestone, Fe' decrease the wh~tcness nf CaCO;. md Mg" increase the yield of aragonite. 3. The pHrange of vaterite and aragonite are formed with high yield is 8-11, and Calcite is famed in pH 6-8 with big particle size of 1over and in pH 11-13 with small particle size of I under. 4. The yicld of calcite and aragonite was increased by addingthc seed cryst.al nf itself.d cryst.al nf itself.

• Management & Information Systems Review
• /
• v.32 no.5
• /
• pp.69-88
• /
• 2013

This study aimed to analyze the effects that the exchange relationship among employees engaged in the wedding industry in Busan, Ulsan and Gyeongnam area exerted on job satisfaction and voluntary service intentions. For this purpose, a theoretical model was presented based on previous studies and the relationship among variables was analyzed based on the analysis results through a survey. There have recently been great difficulties in the whole wedding industry due to the global economic depression and the low birthrate. Moreover, it is hard to optimize the future business environment. In particular, the low birthrate has weakened the demand base of the wedding industry. As a result, it is expected that the competition among companies will be more fierce in the wedding industry. Employees' voluntary service intention become much more important to overcome difficulties in this industry. Employees' voluntary service intentions can be possible when their job satisfaction is achieved. Many studies report the result that this job satisfaction can naturally be achieved when the high quality exchange relationship among a leader, team members (co-workers) and customers is formed. It is viewed that employees' voluntary service intentions should be induced through job satisfaction to improve the profitability through the efficient operation and management of the system. A leader of the organization should make an effort to form the high-quality exchange relationship with members, support so that team members(coworkers) and other employees can get along together and the teamwork can be improved and induce them to improve a high level of service quality with friendly customer services. In spite of the significance of the study discussed above, there are the following limitations in this study. There is a limit to a certain extent in generalizing study conclusions because the study was limited to the Busan, Ulsan and Gyeongnam area. If practical surveys which full- and part-time employees are included in the composition of samples are conducted for wedding suppliers in the country in the future, the quality of study will be able to improve.