• Journal of the Mineralogical Society of Korea
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• v.26 no.1
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• pp.45-54
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• 2013

In order to dissolve Au, Ag, and other valuable metals from gold ore concentrate, raw gold concentrate was pre-treated by roasting and salt-roasting at $750^{\circ}C$. The roasted concentrate was treated with aqua regia digestion to dissolve the valuable metals and higher amount of Au, Ag, and valuable metals were extracted from the roasted concentrates than from the raw concentrate. Higher amount of these metals were also extracted from the salt-roasted concentrate than from the roasted concentrate. The results of the gold dissolution experiments showed that the gold dissolution was most efficient when particle size, roasting temperature, and the percentage of added salt in salt roasting were about $181{\sim}127{\mu}m$, $750^{\circ}C$, and was 20.0%, respectively. The XRD analysis suggests that quartz and pyrite were not destroyed even through roasting at $750^{\circ}C$ and decomposition with aqua regia. However, through salt roasting, pyrite was completely decomposed, whereas quartz could not be destroyed through salt-roasting at $750^{\circ}C$ and aqua regia digestion. Accordingly, it was expected that the gold contained in quartz can not be dissolved through salt-roasting and treatment with aqua regia.

• Korean Journal of Organic Agriculture
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• v.21 no.3
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• pp.403-411
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• 2013

This study was performed to examine whether it is possible to promote rice growth by midsummer drainage without damage of golden apple snails in environment-friendly rice farming. The effect of drainage on the life of snails was examined in a greenhouse before the filed experiment. Spats (young shells) of snails survived 100% at 12 days after drainage, and 93.3% at 15 days after drainage. The midsized shells survived 100% at 9 days, 93.3% at 12 days, and 86.6% at 15 days after drainage. In the field experiment, 10-days drainage did not affect the snail population and there was no significant difference of weeding activity of snails between the midsummer drainage treatment and the continuous submerged treatment. The plant height and the effective tiller number in the midsummer drainage treatment were higher than those of the continuous submerged treatment. The rice yield of midsummer drainage plot was 511kg/10a, which was 66kg/10a higher than 445kg/10a of continuous submerged plot. In conclusion, midsummer drainage could increase rice growth and yield without damage of golden apple snails in the environment-friendly rice farming.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.9-15
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• 2009

The purpose of this study was to find out the optimum SMP carriers in seeds of 12 pepper cultivars to alternate Micro-eel E. It showed that calcium carbonate caused the lower germination rates in proportion of water volumes and the radicle protrusion during priming period. Micro-cel E induced also the radical protrusion, even though it shortened $T_{50}$ in Wang cultivar, in proportion of water volumes. Diatomaceous earth shortened both $T_{50}$ and Mean days germination(MDG) in Choyang and Hyangchon cultivars, although it caused the radicle protrusion in treatment of $1.5{\times}$ water proportion. In Wang cultivar, Diatomaceous earth shortened $T_{50}$ by 0.60 and 0.05 days at 1.0 and $1.5{\times}$ water proportions respectively compared to the Micro-cel E at 5.0 and $7.0{\times}$ water proportions. Therefore, it could be suggested that Diatomaceous earth for the carrier might be suitable in pepper cultivars to alternate Micro-cel E, and $1.0{\times}$ water proportion should be available for processing.

• Journal of the Korean Society of Floral Art and Design
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• no.37
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• pp.157-166
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• 2017

To select fruit trees for urban garden with Elaeagnus umbellata var. coreana, Malus domestica 'Alps Otome', Prunus mume, Ribes nigrum, Rubus fructicosus, and Vaccinium corymbosum 'Reka', growth characteristics of these 6 species were compared and effect of trickle irrigation and shading on the growth of these fruit trees were investigated that these treatments were carried out how much these trees are endurable exposed to improper conditions. After passing the winter, E. umbellata var. coreana, M. domestica 'Alps Otome', P. mume, and V. corymbosum 'Reka' showed the highest survival rate, in contrast to R. nigrum with the lowest of 56.0%. In 9 months after planting, the hight growth rate of 62.3% was shown in P. mume but that of E. umbellata var. coreana was stagnant during experimental period. Flowering rate over 80.0% were shown in E. umbellata var. coreana, M. domestica 'Alps Otome', R. fructicosus, and V. corymbosum 'Reka'. On the other hand, R. nigrum has not ever flowering branches. Other species except E. umbellata var. coreana and R. nigrum have about 10 days in flowering duration. After flowering, fruition rate has shown significant difference among 6 species. As a result of both treatment of trickle irrigation and shading, leaf area and leaf weight of E. umbellata var. coreana, M. domestica 'Alps Otome' significantly inceased with treatments that have not affected other species. Based on these result, it is possible to deploy suitable fruit trees to specific garden condition after selecting various fruit trees.

• Journal of the Mineralogical Society of Korea
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• v.25 no.3
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• pp.123-130
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• 2012

Leaching experiments of gold and silver from roasted concentrate were carried out using a chlorine-hypochlorite solution. The leaching rate of gold was 75% at 1.5:1 ratio of chlorine and hypochlorite and increased to 81% with adding 1 M NaCl. However, at 1% pulp density and at $65^{\circ}C$, the leaching rates of Au were close to 100%. XRD analysis identified quartz in the solid residues after digestion of roasted concentrate with aqua regia or chlorine-hypochloride leaching solution. This suggests that the gold may not be leached out of the quartz in aqua regia or chlorine-hypochlorite solution. In order to leach the gold from the quartz, the concentrate will have to be pre-treated through ultra-fine grinding or treated with stronger oxidative agents.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.1-8
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• 2009

Treatment duration of 12 pepper species by 3, 5, 7 days examined result, optimum processor of 12 pepper cultivars and carrier : water proportion was difference in species. However, radicle protrusion during priming(RPDP) does not happened and heightens germination rate, and Wang and Manitta species were 1:3(ratio), 7 day by treated that can shorten $T_{50}$, and all of the 10 cultivars were regard to processing of 1:7(ratio), 3 days was make satisfactory progress. Also cultivars of Jongggip was investigated by cultivars which germination rate and $T_{50}$ according to treatment duration and water proportion was irregular tendency than other cultivars. It was suggested that $20^{\circ}C$ was stable to radical protrusion and improved germination, while from $15^{\circ}C$ to $35^{\circ}C$ examined.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.234-240
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• 2005

This study was conducted to identify cross compatibility with table grape and pollen characteristics by flower type in Vitis amurensis Rupr. (GW-22, GW-45, GW-56, GW-200, GW-202 and GW-300) collected in Gangwon area. Flower structure, germinability and morphology of pollen, and cross compatibility with table grape were examined. Flowers of GW-22 and GW-56 had an aborted gynoecium and five erect fdaments, and all of them was male. The percentage of pollen germination of GW-22 and GW-56 on the agar medium was 27.6-29.8%. Flowers of GW-45, GW-200, GW-202 and GW-300 had well-developed pistils and five stamens with curled filaments. The percentage of pollen germination of female plant on the agar medium was 0%. Pollen grail)s from GW-22 and GW-56 (male flower) have symmetrically distributed three furrows on their surface and each furrow contains a germ pore at the equatorial level (Tricolporated). GW-45, GW-200, GW202, and GW-300 (Female flower) produced pollen grains with no germinative structures (acolporated). In self-pollina-tion of female flowers, berries of clusters were no berry and no seed. Therefore, flower structure in V. amurensis proved to be that of other dioecious Vitis species. In cross combination of female and male flower of V. amurensis made normal seeds. In cross combination of table grape and V. amurensis of male flower made normal seeds. But, in cross combination of female flower of V. amurensis did not make seeds. Therefore, V. amurensis was cross compatible with vitis spp, and V. amurensis varieties may contribute to breeding studies of Vitis spp.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.363-373
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• 2013

This study investigates the dispersion and behavior of Au and heavy metals in the water system (soil, AMD and stream sediment) at the abandoned Bonjeong gold mine, based on XRD, aqua regia, sequential extraction, and physico-chemical analyses. The XRD analyses targeted quartz and kaolinite in the mine waste soil and quartz and goethite in stream sediment. The physico-chemical analyses of AMD with increasing distance from water system showed that pH increased from 3.00 to 3.19 and Eh decreased from 450 to 396 mV. The Au content in AMD ranged from 0.68 to 0.97 mg/L upstream, but was not detected downstream. The Au content of stream sediment was 13.76 to 22.85 mg/kg. Sequential extraction from stream sediment revealed 10.84% exchangeable (STEP I), 11.09% carbonates (STEP II), 25.53% Fe-Mn oxides (STEP III), 26.62% organic matter (STEP IV), and 24.61% residual (STEP V).

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.61-65
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• 2005

Egg-forming and preservation methods for the indoor-rearing system of the emma field cricket, Teleogryllus emma, were investigated. The oviposition preference experiment on different mats, soil(natural oviposition mat) and $oasis^{\circledR}$(artificial oviposition mat), showed that T. emma preferred to oviposit on the $oasis^{\circledR}$. On the other hand, $oasis^{\circledR}$ had more inactive number of eggs laid per female and hatchability than another. However, the number of eggs laid per female and hatchability within 50 days after emergence were better than soil. The experiment on the hatching of the eggs showed that eggs could be stocked at $10^{\circ}C$ for 40 days with 14 day pre-period after laying, representing $62.1\%$ hatchability, when considering generation shortening. On the other hand, When it had been kept in cold storage for 90 days at $7.5^{\circ}C$ with 14 day pre-period after laying it, appeared to be the most suitable for long period-storage method by hatchability $65.1\%$.

• Journal of Conservation Science
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• v.33 no.1
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• pp.25-33
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• 2017

The stone lantern of the four guardian kings in the Beopjusa temple at Boeun was mainly made of biotite granodiorite consisting of porphyritic-textured potassium feldspar and included in ilmenite series. A base stone made of alkali granite was buried, after founded its place during an earlier restoration process. Cracking and break out are noticeable on this object. In addition, discoloration, salt crusting, and epiphytes were observed. The lantern was vulnerable in terms of physical and structural stability caused by cracking in the front and back of the light chamber and in the non-horizontal direction. According to the conservational condition of the stone lantern, structural reinforcement was carried out based on calculations, including those on the position, size, and anchor length of the titanium stiffener. Chemical and biological pollutants were washed off without damage to the surface of the stone material. Oxygenated iron pieces were replaced with titanium. Ethyl silicate was applied to the surface of the lantern for consolidation and smooth drainage.