• Economic and Environmental Geology
• /
• v.34 no.6
• /
• pp.617-625
• /
• 2001

The Skaergaard intrusion is widely considered a type example of a strongly fractionated, layered intrusion that has undergone extensive in situ igneous differentiation. The Intrusion, therefore, should be a good locality for modeling trace element vriation in a closed system. Previous studios (Haskin and Haskin, 1968; Faster et al., 1974), however, have suggested thats the rare earth elements in whole rocks and mineeral separates from the Intrusion did not fellow the expected trend for closed system crystatllization. Trace element modeling using published distribution coefficients, modal abundances of the coexisting minerals, and the concentration of trace elements In whole rocks and mineral separates from the Skaergaard Intrusion, reveals that the rare earth elements were significantly Influenced by the crystallization of abundant apatite in the Layered Series suring the final stages of crystallization. The results of trace element modeling also suggcsts that apatite, which appears sporadically in the UBS, is not a primary liquidus phase in these samples as previously suggested (Naslund, 1984) but an interstitial phase that (lid not directly effect trace element abundances In the evolving magma As the Skaergaard magma coaled convection, or convected as small Isolated cells during the final stages of differentiation, an elebated $P_{H2O}$ Induced by accumulation of volatile elements near the roof of the magma chamber ingibited or delayed the precipitation of primary apatite in the UBS If the Skaergaard differentiation Is modeler assuming primary apatite crystallization In the upper par of the LS where abundant modal apatite is present, and only late stage crystallization of apatite In the UBS where apatite Is less abundant, rare earth elements abundances follow a closed system variation trend. These results rule but any differentiation model for the Skaergaard Intrusion that Includesvolumetrically significant injections or discharges of magma Into or out of the chamber during the final 20% of the crystallization history.

• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.1
• /
• pp.173-190
• /
• 1992

Considerable number of offshore platforms have been built in Korean shipyards ever since 1976. Unlike for the cases of building ships, however, negligible efforts have been made to establish planning methodology for building onshore platforms. Severe congestion has been shown in the processes of assemblying modules of platforms. The module which is the upper part of a platform is a steel structure accommodating various types of outfittings and machinaries. The production planned without proper consideration on allocating work loads by trade used to show severe interferences among trades of workers and resulted in delayed completion. In this paper, a method of planning module assembly in consideration of leveling work loads by trade is discussed. A system of planning has been formulated and tested on a exampled case of producing a mix of 72 modules. The test showed a possibility of saving 31% of manpower and trimming 11% of through put time.

• Korean Journal of Plant Resources
• /
• v.8 no.3
• /
• pp.237-246
• /
• 1995

In this study, the callus was induced and regenerated from the immature embryo and ultrastructural characteristics of developmental stages in Citrus junos SIEB, were investigated. The yellowish callus was induced by 5 to 6 week of culture of citrus. In proliferation callus after 6 weeks of culture, large vacuole was formed by fusion between adjacent small ones. In the non-embryogenic callus cultured for 12weeks, re-differentiated cells of callus showed the large nucleus with globular nucleus and amyloplast with large size of starches. In the embryogenic callus cltured for 14-16 weeks, the active exocytosis occurred in cells, secretory vesicles appeared on cell membrane and small particles from cytoplasm were released to intercelluar space. In the embryogenic callus cultured for 24 weeks, a sperical type of chloroplast bounded on cytoplasm by double membrane and typical grana was dispersed equally among matrix. In the normal plantlet after 26 weeks of culture, a lot of vessels and companion cells apperaed in the leaf cell of plantlet. In the normal plantlet after 30 weeks of culture, the immature leaf showed many small companion cells, sieve tubes and central vacuole. Also, the secondary vacuole protruded into the central vacuole and elongated chloroplasts near plasma membrane. In the matured plant habituated on the soil, palisada tissue composed of orderly arranged cells contained the nucleus in the center of the cell and large vacuoles on either side of the nucleus.

• Korean Journal of Plant Resources
• /
• v.20 no.4
• /
• pp.292-297
• /
• 2007

To explain the relationship between plant size and seed production, change of sexual organs, relationship between each organs of Convallaria keiskei population, which is located in Gwiyeo-2-ri, Namjong-myeon, Gwangju-si, Gyeonggi-do these were studied from April to August 2002. This study was carried out two ways. One way was to set up the permanent quadrat to explain the change of sexual organs. The other was to carry the collected sample to the laboratory and analysis it to explain the relationship between each organs and energy division of seed production. In the Convallaria keiskei population, the average number of leaf which blooming shoot in the permanent quadrat was 2 and I could find the late leaf size was larger. It was found that, per shoot, the average number of flower was 7.9, fruit was 5.4 and seed was 16.1. Each properties in the sexual organ, underground part size and leaf size, had correlation of 1% or within 5%. The flowering time of the Convallaria keiskei was from April 26 to May 11. Therefore, it can be estimated that the blooming period was $8{\sim}9$ days in just one flower. Among that flowers bloom at the beginning May, 80% fruit at the end of May, and 68% fruit at the end of August. The dry weight of seed had more correlation dry weight of underground part than leaf area.

• Journal of the Korean association of regional geographers
• /
• v.5 no.2
• /
• pp.29-45
• /
• 1999

This study reviewed theories on entrepreneurial local governance and inquired the changing regional policy in Chonnam region. The region became exposure as the direct investment unit of global capital by globalization of capital, the inter-regional competition and the relative reduction of the role and function of nation state. Therefore local government have the relative autonomy and the region is effected as the chosen space by capital according to the free movement of capital. It has been argued that there has been a reorientation of urban governance away from the local provision of welfare and services to a more outward-orientated stance designed to foster and encourage local growth and economic development. These profound changes in the way that cities operate have seen the public sector taking over characteristics once distinctive to the private sector leading many commentators to term such modes of governance as entrepreneurial. In Chonnam region, many local governments are introducing entrepreneurial policies for regional development. It appears as place marketing strategy to attract capital and tourists. This strategy is very important to used identity or culture of region in order to make the attractive region. The entrepreneurial characteristics and strategies appear as image unification of region, commodity development of natural or cultural resource, event and business projects. From this point of view, the entrepreneurial policy that is based upon regional growth can cause the problem of social justice like distributional distortion and inequality.

• Korean Journal of Plant Resources
• /
• v.33 no.2
• /
• pp.63-72
• /
• 2020

Fermented complex from garlic and nine medicinal plants were developed as a natural whitening material. Tyrosinase inhibition activity was determined and four active compounds were isolated. The nutritional components of fermented garlic complex (FGC) were analyzed to confirm the applicability as a functional food material. Tyrosinase inhibitory effect of FGC was 88.6%. Methanol extract was partitioned with EtOAc, n-BuOH and H₂O. From the EtOAc fraction (47 g), which showed the highest yield, active fractions were separated by repeated TLC, silica gel and ODS column chromatography to isolate active compounds. The chemical structures of the isolated compounds were analyzed by NMR and MS spectra. Phenylpropanoid compounds of 2,4,5-trihydroxy-benzenepropanoic acid (1) (1.9 mg) and 2,3,5-trihydroxy-benzenepropanoic acid (2) were confirmed. In addition, 2,4-dihydroxy-hydrocinnamic acid (3) (3.3 mg) and (+)sesamin (4) (6.1 mg) were isolated. These compounds will be useful as index compounds or functional compounds in FGC.

• Environmental and Resource Economics Review
• /
• v.20 no.4
• /
• pp.827-858
• /
• 2011

In Korea, various environmentally harmful subsidies are granted in agriculture, fishery, energy, electricity, transportation, steel and shipbuilding industry. Examples include tax-exempt fuel for agriculture & fishery, VAT- exemption for briquette & anthracite, temporary subsidy for fuel, production stabilizing subsidy for coal mining, subsidy for briquette. Korea's yearly total subsidy in energy area is about 5,291 billion won, among them is 4,870 billion won. To reduce air pollutants and to mitigate climate change, Korea has to review the phase-out of environmentally harmful subsidies and the phase-in of environment-friendly subsidy. The reduction or removal of environmentally harmful subsidies will enhance economic efficiency and bring about environmental benefits. Economic efficiency means less use of inputs, which reduces environmental cost and improves social benefits. This paper applies the Shoven and Whalley's model to the Korean economy and analyzes the general equilibrium incidence effects of reforming environmentally harmful subsidies in the energy and electricity in Korea. We consider several counterfactual scenarios in which current environmentally harmful subsidies are reduced or abolished, compare them with the reference case in the economy, and evaluated the change in efficiency costs and distributional incidence of tax reforms related to subsidies.

• Economic and Environmental Geology
• /
• v.34 no.2
• /
• pp.157-166
• /
• 2001

Numerous base-metal bearing hydrothermal quartz vein deposits occur in the Hunan province of southern China. The Tangguanpu lead-zinc-tin-silver mine is the major producer among these deposits. Lead-zinc-tin-silver mineralization occurs in a single stage of massive quartz veins which filled fractures in fault zones within Paleozoic metasedimentary rocks. Sphalerite, chalcopyrite, galena, pyrite, arsenopyrite and pyrrhotite are the principal sulphide minerals in the Tangguanpu lead-zinc ores with minor amounts of tin- and antimony-bearing sulphides (stannite, teallite, boulangerite and tetrahedrite). Based on the iron and zinc partitioning between coexisting stannite and sphalerite, the formation temperature for this mineral assemblage range from 300$^{\circ}$ to 330$^{\circ}$C, which relatively agree with the upper part of homogenization temperature of fluid inclusion in quartz (20T-358$^{\circ}$C). Fluid inclusion data show that main lead-zine-tin-silver mineralization occurred from $H_{2}O$-NaCl fluids with relatively low salinities (11.2-7.3 wl.% eg. NaCI) at temperatures between 207$^{\circ}$ and 358$^{\circ}$C. The relationship between homogenization temperature and salinity suggests a history of cooling and dilution followed by initial boiling. Evidence of initial fluid boiling may indicate the fluid trapping pressures of 180 bars. The ${\delta}^{34}S{{\Sigma}S}$ values of -5.0 to 1.1 %, indicate an igneous source of sulfur in the Tangguanpu lead-zinc-tin-silver hydrothermal fluids.

• Resources Recycling
• /
• v.26 no.4
• /
• pp.79-87
• /
• 2017

Extraction and separation behaviors of La, Ce, Pr, Nd and Sm from light rare earth multi - component mixed solutions by Cyanex 572 were studied. As extractant concentration increased, the $pH_{50}$ values of all the five components decreased. When extractant concentration was larger than 0.6 M, the separation factor of La and Ce, Nd and Sm was higher than 10, while the separation factor between Ce and Pr, Pr and Nd was as low as 0.5~2.2. Addition of TBP to the 0.6 M Cyanex 572 had little synergistic effect on the phase separation rate and separation factor. From the analysis of experiment results, group separation of [La]/[Pr, Nd, Sm] and [Pr, Nd]/[Sm] could be possible, but in case of the group separation between [La, Ce] and [Pr, Nd] was not available because of the low separation factor between Ce and Pr.

• Analytical Science and Technology
• /
• v.22 no.3
• /
• pp.219-227
• /
• 2009

The steroid compounds in Rhodiola sachalinensis were determined with adsorption column chromatographic purification and GC/MS. Sterols were extracted by sonication and Soxhlet with ethanol and dichloromethane, respectively. The extract was partitioned with chloroform and water using liquid-liquid extraction, and purified with a silica column after the sterols had been converted to the corresponding silyl derivatives with BSTFA. Eighteen free sterols, including $\beta$-sitosterol, stigmasterol and cycloartenol, and nine sterol conjugates were found from Rhodiola sachalinensis by GC/MS. Among them, cholest-5-ene-3-ol, cholesterol, stigmasterol, $\beta$-sitosterol were confirmed and quantified with sterol standards. Most sterols were presented in the chloroform part, with $C_{29}$ being the most abundant group in this sterol group. $\beta$-sitosterol was the most abundant compound with a relative content of 45.94% followed by ergost-7-ene-3-ol (11.33%), 4,14-dimethyl-ergosta-8,24(28)-diene-3-ol (7.07%), stigmasterol (6.09%), cycloartenol (5.43%) and 4-methyl-cholest-5-ene-3-ol (5.39%).