• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.18 no.3
• /
• pp.122-130
• /
• 2013

To examine floc characteristics of cohesive bed sediment of the Yeongsan River estuary, a floc camera system has been developed and utilized to observe flocs under varying conditions. In order to validate the floc camera system, sand particles were passed through 88-125 and $63-88{\mu}m$ sieves and observed within the laboratory. Mean grain size and settling velocities were found to be 102 and $56.2{\mu}m$ and 6.7 and 5.9 mm/s, respectively. Artifacts of particles estimated outside of the sieve range are attributed to being imaged out of the depth of focus. However, as mean grain size and settling velocity of each size class were within the confidence interval, the floc camera system was confidently used to examine cohesive bed sediments of Yeongsan River estuary. The bed sediment sample was prepared with a concentration of 0.1 g/L in 0 psu deionized water. The mean grain size, settling velocity and fractal dimension of flocs were $40.6{\pm}0.66{\mu}m$, 14 mm/s, and 2.86, respectively. Experiments were also conducted using different salinities (10 and 34 psu) and sediment concentrations (0.1 and 0.3 g/L). Despite changing these parameters, the mean observed grain size and settling velocities were found to be the same within the error range of the system. The relatively higher values of settling velocity and fractal dimension are considered a result of the sediment containing relatively small concentrations of organic matter. Moreover, consistent floc size over various grain sizes and concentrations may be the result of insufficient turbulence to aggregate flocs.

• Economic and Environmental Geology
• /
• v.42 no.4
• /
• pp.301-314
• /
• 2009

The Taebaeksan mineralized province, which is the most important one in South Korea, is rich in zinc-lead-tungsten-iron-copper-molybdenum-silver-gold mineral resources and has a diversity of deposit styles. These deposits principally coexist in time and space with porphyry-related epigenetic deposit such as skarn, hydrothermal replacement, mesothermal vein, and Carlin-like deposits. The magmatic-hydrothermal systems in the Taebaek fold belt is genetically characterized by the Bulguksa subvolcanic rocks(ca. $110{\sim}50\;Ma$) related to northwestward subduction of the paleo-Pacific Plate. The most important zinc-lead deposits in the area are the Uljin, Yeonhwa II and Shinyemi skarn, the Janggun hydrothermal replacement, and the Yeonhwa I intermediate-mixed (skarn/hydrothermal replacement) ones. In the present study, we present a compilation of metal production and mineral assemblage of the zinc-lead deposits. The metal difference of deposit styles in the area indicates a cooling path from intermediate-sulfidation to low-sulfidation state in the polymetallic hydrothermal system, reflecting spatial proximity to a magmatic source.

• Economic and Environmental Geology
• /
• v.26 no.2
• /
• pp.187-191
• /
• 1993

FT dating of twelve zircon concentrates was carried out on the igneous rocks in the study area. The FT results from this study are younger than those of Rb-Sr or K-Ar by 20Ma, probably, due to the different closing temperature of the minerals. The obtained ages are $161{\pm}11Ma$ to $150{\pm}10Ma$ for the gneissose granodiorite and the Geochang granodiorite. It is estimated that the intermediate and basic rocks were formed at twice: one from $148{\pm}13Ma$ to $144{\pm}8Ma$, and the other from $122{\pm}8Ma$ to $104{\pm}7Ma$. In the case of the Gajo granite, the age is $96.5{\pm}5.7Ma$ to $95.4{\pm}6.4Ma$. Although considering the fact that the FT age is younger than the K-Ar age, it is likely that the magmatism in the Jurassic period was most intense in the area, which was associated with the Daebo orogeny.

• Economic and Environmental Geology
• /
• v.46 no.2
• /
• pp.93-104
• /
• 2013

Daejiguksaptapbi (Tapbi) is a memorial stele which is inscribed with personal history of a state preceptor, Daejiguksa Beopkyeong. The Tapbi comprises tortoise-shaped pedestal, dragon top and body stone, and the body stone is remained in 255 pieces by excavation in Samcheonsaji temple site of Seoul. The Tapbi is composed of tuffaceous breccia for the body, coarse-grained pink feldspar granite for the pedestal and fine-grained granite for the top. As a result of geological survey to find a rock provenance of the Tapbi rock, the tuffaceous breccia is found in the banks of Gangwha straits, and the pink feldspar granite and fine-grained granite are found around the temple site in Mt. Bukhansan. Each rock shows similarities to the Tapbi in lithology and mineralogy. Also, geochemical data of major, some trace and rare earth elements verify their cognation in each rock type. It can be interpreted that the provenance of the body stone is distant as Gangwha area, and the provenance of the pedestal and top stones are near the temple site. The results can be utilized to restore the Tapbi by using the same rocks.

• Journal of Science Education
• /
• v.34 no.1
• /
• pp.93-104
• /
• 2010

The purpose of this study was to investigate the high school students' interests and and perceptions about the soil concepts. The data were obtained from 72 boys and 82 girls at a high school in Daegu area. The questionnaires were developed 8 questions for students' interest and 10 questions for students' understanding. The results of this study were as follows. In the examination of students' interest on the soil concepts, boys showed 3.2point(64.9%) out of 5point and girls showed 3.2point(64.6%) out of 5 point. Furthermore, a percentage of correct answers for understanding on the soil concepts was 47.4%. In detail, Boys had 48.2% and girls had 46.6%, boys showed higher understanding about soil concepts than girls. And students understood soil concepts by a visible side, to approach the soil concepts from a biological point of view, rather than a geologic one. Also high school students didn't think soil concepts to consist of minerals and rocks from a geologic point of view. Correlation between interest and understanding on the soil concepts was very weak by showing r=.170(p<.05).

• The Journal of the Petrological Society of Korea
• /
• v.23 no.4
• /
• pp.337-349
• /
• 2014

We measured rare earth element and Zr concentrations of USGS granite standard material GSP-2 and GSJ granite standard material JG-1a to clarify the effect of zircon during rare earth element analysis using ICP-MS. We also measured rare-earth element and zirconium (Zr) contents of zircon from granite by acid-digestion methods using conventional teflon vial and pressure-bomb. The results show that acid-digestion using teflon vial dissolved ca. 50% of zircon compared to pressure-bomb method. The Zr contents of JG-1a and GSP-2 gave ca 50% of reference value. However, rare-earth element abundance of JG-1a and GSP-2 were similar to those of reference values. This suggests that the decomposition degree of zircon might give a negligible effect on a petrological and geochemical interpretation using chondritenormalized REE pattern.

• The Journal of the Petrological Society of Korea
• /
• v.22 no.1
• /
• pp.1-8
• /
• 2013

Physical properties, XRF, UV-Vis, FTIR studies were carried out in order to characterize gemological features of ruby from Tajikistan. Fluorescence reaction of the Tajikistan ruby to short wave ultraviolet was moderate to very strong in red and long wave ultraviolet rays was weakly detected. UV-visible analysis strong absorption bands at 468.5, 475, 476.5 nm and broaden bands at 550 nm were observed for ruby due to $Cr^{3+}$. According to FT-IR analysis, all rubies from Tajikistan showed the similar patterns and kaolinite peaks at 3500, 3617, 3630, $3677cm^{-1}$ and boehmite broaden absorption bands at 3085 and $3320cm^{-1}$. Inclusions in Tajikistan ruby are observed solid inclusions, negative crystals, needle and silk inclusions. These distinctive characteristics mentioned above can be used to identify the locality and source of ruby stones from Tajikistan.

• Journal of the Korean earth science society
• /
• v.37 no.6
• /
• pp.332-345
• /
• 2016

The columnar joints in Goheung are developed in three places of Yuju-san area, Palyeong-san and Yongbawi area. Vertical and fan-shaped columnar joints which have maximum width 100 m and maximum heigh 50 m are developed in the Yuju-san area Columnar joints are developed next to the road near the the Yuju-san and along the coast of Jijuk-do. Thick columnar joints of maximum width 1m are developed in the Paryeong-san area. Horizontal columnar joints of maximum width 50 cm at length of polygon side are developed on dyke in the Yongbawi area. The columnar joints show high rate of rectangles and pentagons in the number of polygons. The length of polygon side of columnar joints in study area ranges from 10 to 100 cm, and 20 cm among the range appears in high frequency. Columnar joints are developed vertically to the ground from the cooling surface in Yuju-san and Palyeong-san area. Columnar joints in Yongbawi area are developed vertically to the contact of country rocks. As a result, the columnar joints began cooling from the country rock contact. And columnar joints are developed vertically to contact surface. The rocks in columnar joints is rhyolitic welded tuff in Yuju-san and Palyeong-san area, dacite in Yongbawi area. In the acid volcanic rocks flow structure well developed. The white phenocryst mineral about 2 mm size by eye, is usually feldspar, and includes some quartz. The rate of $SiO_2$ is 70wt.% or more. It is the last stage of differentiation to calc-alkaline series. The columnar joints of the Yuju-san area are expected to be distributed along a band that extends to about 1km east of the stone pit.

• Resources Recycling
• /
• v.8 no.4
• /
• pp.11-19
• /
• 1999

Fly ash generated from (he pulverized coal power plant have caused the serious ocean pollution due to the disposal in the ash pond, the life reduction of a power plant and the waste of re-utilizable resource The research to reuse the unburned carbon and mineral composing of the ash has been progressed. In this study. the physical and chemical characteristics of high grade ash and unburned carbon particles obtained from countercurrent column flotation are investigated. The cleaned ash of the less 0,5% loss on Ignition(LOI) in carbon content is a spherical sphere and 39.8${\mu}m$ in size of MMD(Mass Median Diameter). 2.22 $m^2/g$ of specific area. The morphology of high LOI carbon particles is a amorphousness, 76.6 ${\mu}m$ of particle size and 15.2 $m^2/g$ of specific The high grade cleaned ash and the high LOI ash have some difference in the light of physical. chemical and morphological characteristics

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.44 no.2
• /
• pp.201-210
• /
• 2018

In this study, we formulated oil-in-water emulsion composition for skin care products containing jadeite powder which is well known as far-infrared radiating material. Jadeite powder could sustain stable dispersion in aqueous solvents over a month and this helped mixing it high content in oil-in-water emulsion formulation. To identify the effect of jadeite as a far-infrared radiator materials relating to the skin surface temperature change, we applied emulsion formulation containing 2 weight percent jadeite powder onto facial skin surface and blank formulation together and analyzed surface temperature with thermo-vision. Our results showed that the temperature difference between jadeite powder formulation applied region and blank formulation reached to 1.5 ~ 2.0 degree Celsius. We also performed same test with nephrite powder and titanium dioxide powder but only jadeite powder containing formulation showed significant skin temperature change. To elucidate main cause of heat energy transfer, we tested heat radiation, energy dispersive spectrometer analysis and measured far infrared radiance emissivity, diffuse reflectance spectra and water evaporation rate. We found out jadeite powder could retard water evaporation effectively from the skin surface and resist temperature drop down. This is because of the innate chemical composition and surface structure of jadeite, which can bind with water molecules to form hydrogen bonds. It is concluded that we can develop novel skin care products for moisturizing and thermos with jadeite powder.