• Journal of the Mineralogical Society of Korea
• /
• v.24 no.4
• /
• pp.301-312
• /
• 2011

The study on the atomic structure of iron-bearing silicate glasses has significant geological implications for both diverse igneous processes on Earth surface and ultra-low velocity zones at the core-mantle boundary. Here, we report experimental results on the effect of iron content on the atomic structure in iron-bearing alkali silicate glasses ($Na_2O-Fe_2O_3-SiO_2$ glasses, up to 16.07 wt% $Fe_2O_3$) using $^{29}Si$ and $^{17}O$ solid-state NMR spectroscopy. $^{29}Si$ spin-lattice ($T_1$) relaxation time for the glasses decreases with increasing iron content due to an enhanced interaction between nuclear spin and unpaired electron in iron. $^{29}Si$ MAS NMR spectra for the glasses show a decrease in signal intensity and an increase in peak width with increasing iron content. However, the heterogeneous peak broa-dening in $^{29}Si$ MAS NMR spectra suggests the heterogeneous distribution of $Q^n$ species around iron in iron-bearing silicate glasses. While nonbridging oxygen ($Na-O-Si$) and bridging oxygen (Si-O-Si) peaks are partially resolved in $^{17}O$ MAS NMR spectrum for iron-free silicate glass, it is difficult to distinguish the oxygen clusters in iron-bearing silicate glass. The Lorentzian peak shape for $^{29}Si$ and $^{17}O$ MAS NMR spectra may reflect life-time broadening due to spin-electron interaction. These results demonstrate that solid-state NMR can be an effective probe of the detailed structure in iron-bearing silicate glasses.

• Journal of the Korea Concrete Institute
• /
• v.18 no.1 s.91
• /
• pp.21-28
• /
• 2006

This paper presents both experimental and analytical studies for the development of an ECC(Engineered Cementitious Composites) using ground granulated blast furnace slag(slag). This material has been focused on achieving moderately high composite strength while maintaining high ductility, represented by strain-hardening behavior in uniaxial tension. In the material development, micromechanics was adopted to properly select optimized range of the composition based on steady-state cracking theory and experimental studies on matrix, and interfacial properties. A single fiber pullout test and a wedge splitting test were employed to measure the bond properties of the fiber in a matrix and the fracture toughness of mortar matrix. The addition of the slag resulted in slight increases in the frictional bond strength and the fracture toughness. Subsequent direct tensile tests demonstrate that the fiber reinforced mortar exhibited high ductile uniaxial tension behavior with a maximum strain capacity of 3.6%. Both ductility and tensile strength(~5.3 MPa) of the composite produced with slag were measured to be significantly higher than those of the composite without slag. The slag particles contribute to improving matrix strength and fiber dispersion, which is incorporated with enhanced workability attributed to the oxidized grain surface. This result suggests that, within the limited slag dosage employed in the present study, the contribution of slag particles to the workability overwhelms the side-effect of decreased potential of saturated multiple cracking.

• Journal of Life Science
• /
• v.16 no.6
• /
• pp.904-910
• /
• 2006

Dendritic cells (DCs) are the only antigen presenting cells (APCs) capable of initiating immune responses, which is crucial for priming the specific cytotoxic T lymphocyte (CTL) response and tumor immunity. Upon activation by DCs, CD4+ helper T cells can cross-prime CD8+ CTLs via IL-12. However, recently activated DCs were described to prime in vitro strong T helper cell type 1 $(Th_1)$ responses, whereas at later time points, they preferentially prime $Th_2$ cells. Therfore, we examined in this study the optimum kinetic state of DCs activation impacted on in vivo priming of tumor-specific CTLs by using ovalbumin (OVA) tumor antigen model. Bone-marrow-derived DCs showed an appropriate expression of surface MHC and costimulatory molecules after 6 or 7-day differentiation. The 6-day differentiated DCs pulsed with OVA antigen for 8 h (8-h DC) and followed by restimulation with LPS for 24 h maintained high interleukin (IL)-12 production potential, accompanying the decreased level in their secretion by delayed re-exposure time to LPS. Furthermore, immunization with 8-h DC induced higher intracellular $interferon(IFN)-{\gamma}+/CD8+T$ cells and elicited more powerful cytotoxicity of splenocytes to EG7 cells, a clone of EL4 cells transfected with an OVA cDNA, than immunization with 24-h DC. In the animal study for the evaluation of therapeutic or protective antitumor immunity, immunization with 8-h DC induced an effective antitumor immunity against tumor of EG7 cells and completely protected mice from tumor formation and prolonged survival, respectively. The most commonly used and clinically applied DC-based vaccine is based on in vitro antigen loading for 24 h. However, our data indicated that antigen stimulation over 8 h decreased antitumor immunity with functional exhaustion of DCs, and that the 8-h DC would be an optimum activation state impacted on in vivo priming of tumor-specific CTLs and subsequently lead to induction of strong antitumor immunity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.17 no.4
• /
• pp.270-282
• /
• 2012

This study was conducted to investigate the impact of sand addition to an intertidal for the development of the Manila clam habitat on benthic community structure. For this, we focused on the spatio-temporal changes in the surface sediment condition and benthic community structure before and after the event. Study site was an sandbank in Gonam-myeon, Taean-gun where sand added to on July 2010. We set three stations at each of sand adding area (experimental plot) and non sand-adding area (control plot) and did sampling works ten times from June 2010 to October 2011. Directly after the event, surface sediments changed to very coarse sand, but the state was not maintained over four months because of seasonal sedimentation and finally got back to very fine sand in eight months. The number of species and density were temporarily reduced right after the event and crustacean species such as Apocorophium acutum, Photis sp. were most negatively affected by the event. However, the number of species recovered from the reduction in three months and density did in four months due to the recolonization by the existing species and species in the vicinity of the plot. During the study period, dominant species continuously changed from the species such as A. acutum, Photis sp. at the time before the event, through the species such as Heteromastus filiformis, Macrophthalmus japonicus at the time right after the event, to the species such as Musculista senhousia, Ruditapes philippinarum, Mediomastus californiensis in the latter part of the study period. Although surface sediment properties and ecological indices recovered within a certain period after the event, the recovery of community structure has never been observed up to the end of the study.

• Economic and Environmental Geology
• /
• v.34 no.5
• /
• pp.471-483
• /
• 2001

The pH values of the mine and surface water from the Tohyun mine creek were higher compared with those of groundwater, and 2nd round samples in same sites were even alkaline. The stream and mine waters belong to the characteristics of (Ca+Mg)-(SO$_4$) and (Ca+Mg)-(HCO$_3$) types, and groundwaters have to the (Ca+Mg+Na+K)-(HCO$_3$+SO$_4$) type. As the 2nd samples. concentrations of mostly anions are increasing compared with the forder samples. However, the mostly cation concentrations are decreasing. The hydrogeochemistry indicate that water quality is different chemical characteristics and evolution trends. The range of $\delta$D and $\delta$$^{18}$ valutes (relative to SMOW) in the waters are shown in -62.2 to -70.1$\textperthousand$, and -8.1 to -9.4$\textperthousand$. The values are plowed parallel to $\delta$D=8$\delta$$^{18}$ O+ (6$\pm$4). The d values of groundwater show 2.4, which is lower than the surface (5.2) and mine (7.6) waters. Strontium concentra titans range from 0.025 to 11.844 mg/$\ell$ in all kinds of water samples, but the groundwater has the highest contents The $^{87}$ Sr/$^{86}$ Sr ratios (0.7115 to 0.7129) show more lightened to the groundwater. The $\delta$$^{18}$ O value, Ca and Sr contents are decreased with $^{87}$ Sr/$^{86}$ Sr increasing, because it is support to the altitude effects of the sampling sites rather than a water-rock interaction of environmental isotope. Using computer code of WATEQ4F, saturation indices of albite, Quartz, gibssite and gypsum are calculated to be soluble. The calcite and dolomite show super saturation state, however, clay mineral species are plotted boundary between undersaturation and supersaturation. In the Tohyun mine creek, reaction materials with ore wastes arid precipitation have influence upon increasing EC and TDS of the waters independent of pH. The SO$_4$ concentrations in the mine water is 181.845 mg/$\ell$. This is abruptly increase in surface water and then detected 249.727 mg/$\ell$ in the groundwater. As a results of the calculated sulfate mineral solubilities, the sulfate ions became saturation states an above 150 mg/$\ell$ concentrations.

• Journal of the Korean GEO-environmental Society
• /
• v.16 no.12
• /
• pp.45-52
• /
• 2015

With the rising interest in the environment, more attention on ecological restoration for damaged slope surface to restore its original state has been drawn. Generally, the most useful method is vegetation based spray work. This method uses green soil including sewage sludge, sawdust, paper sludge, and weathered granite soil. However, because there are neither accurate information nor test values about green soil, green soil is often lost by environmental factors such as rainfalls and strong winds. To solve the problem of green soil, it is necessary to prepare design standards about green soil, and conduct studies to deal with green soil loss in consideration of various variables including basic material property, soil quality of slope surface, and weather. This study was conducted in the mixture of green soil and eco-friendly soil stabilizer. With green soil, basic material property test and compaction test were conducted for the analysis on the basic characteristics of green soil. In the mixture with soil stabilizer at a certain ratio, we conducted shear strength test depending on the ratio in order to analyze the maximum shear strength, cohesion and the change in internal friction angles. Furthermore, in the mixture ratio of green soil and soil stabilizer, which is the same as the ratio in the shear strength test, an inclination of slope surface was made in laboratory for the analysis on erosion and germination rate. Finally, this study evaluated the most effective and economic mixing ratio of soil stabilizer to cope with neighboring environmental factors. According to the test, the shear strength of green soil increased up to 51% rely onto the mixing ratio of and a curing period, and its cohesion and internal friction angle also gradually increases. It is judged that the mixture of soil stabilizer was effective in improving shear strength and thereby increased the stability of green soil.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.3
• /
• pp.223-233
• /
• 2015

In order to evaluate the pollution of heavy metals in offshore surface sediments around shipyards in Korea, surface sediment samples were collected at eleven stations around four major shipyards located in the southeastern coast of Korea in summer 2010 and nine kinds of heavy metals such as copper(Cu), zinc(Zn), cadmium(Cd), lead(Pb), chrome(Cr), arsenic(As), mercury(Hg), iron(Fe) and aluminum(Al) in sediments were analyzed. The concentrations of Cu at all sampling stations were in the range of 47.10~414.96 mg/kg and exceeded TEL(Threshold Effects Level) 20.6 mg-Cu/kg of Korean marine environmental standards for offshore sediments and ERL(Effect Range-Low) 34.0 mg-Cu/kg. The concentrations of Cu at seven stations around four shipyards were 65.18~414.96 mg/kg and exceeded PEL(Probable Effects Level) 64.4 mg-Cu/kg of Korean marine environmental standards for offshore sediments. The concentration of Cu at one station around B-shipyard was 414.96 mg/kg and exceeded ERM(Effect Range-Median) 270.0 mg-Cu/kg. The concentrations of Zn at all stations were in the range of 135.09~388.79 mg/kg which exceeded ERL 150.0 mg-Zn/kg. The concentrations of Zn at seven stations around four shipyards were 157.57~388.79 mg/kg and exceeded PEL 157.0 mg-Zn/kg. The concentration of Zn at one station around B-shipyard was 388.79 mg/kg and was approaching ERM 410.0 mg-Zn/kg. The concentrations of Cd at all stations were in the range of 0.11~0.54 mg/kg and were below TEL 0.75 mg-Cd/kg and ERL 1.2 mg-Cd/kg. The concentrations of Pb at all stations were in the range of 18.04~105.62 mg/kg. The concentrations of Pb at two stations around B-shipyard were 73.87~105.62 mg/kg which exceeded TEL 44.0 mg-Pb/kg and ERL 46.7 mg-Pb/kg, and were below PEL 119.0 mg-Pb/kg and ERM 218.0 mg-Pb/kg. The concentrations of Cr at all stations were in the range of 51.26~85.39 mg/kg. The concentration of Cr at one station around B-shipyard was 85.39 mg/kg and exceeded ERL 81.0 mg-Cr/kg. The concentrations of As at all stations were in the range of 8.70~22.15 mg/kg which exceeded ERL 8.2 mg-As/kg and were below ERM 70.0 mg-As/kg. The concentrations of As at eight stations around A-shipyard, B-shipyard and D-shipyard were 14.93~22.15 mg/kg which exceeded TEL 14.5 mg-As/kg and were below PEL 75.5 mg-As/kg. The concentrations of Hg at all stations were in the range of 0.02~0.35 mg/kg. The concentrations of Hg at three stations around A-shipyard were 0.11~0.13 mg/kg which were almost equal to TEL 0.11 mg-Hg/kg. Those at two stations around B-shipyard were 0.27~0.35 mg/kg which exceeded TEL 0.11 mg-Hg/kg and ERL 0.15 mg-Hg/kg, and were below PEL 0.62 mg-Hg/kg and ERM 0.71 mg-Hg/kg. The concentrations of Fe and Al at all stations were in the range of 2.90 3.66 % and 3.12 6.80 %, respectively. These results imply that heavy metals such as copper, zinc, lead, arsenic and mercury were likely to be transferred to marine environment from shipyards, especially from B-shipyard.

• Korean Journal of Organic Agriculture
• /
• v.25 no.1
• /
• pp.135-148
• /
• 2017

Response Surface Methodology (RSM), which is combining with Plackett-Burman design and Box-Behnken experimental design, was applied to optimize the ratios of the nutrient components for carotenoid production by Rhodobacter sphaeroides PS-24 in liquid state fermentation. Nine nutrient ingredients containing yeast extract, sodium acetate, NaCl, $K_2HPO_4$, $MgSO_4$, mono-sodium glutamate, $Na_2CO_3$, $NH_4Cl$ and $CaCl_2$ were finally selected for optimizing the medium composition based on their statistical significance and positive effects on carotenoid yield. Box-Behnken design was employed for further optimization of the selected nutrient components in order to increase carotenoid production. Based on the Box-Behnken assay data, the secondary order coefficient model was set up to investigate the relationship between the carotenoid productivity and nutrient ingredients. The important factors having influence on optimal medium constituents for carotenoid production by Rhodobacter sphaeroides PS-24 were determined as follows: yeast extract 1.23 g, sodium acetate 1 g, $NH_4Cl$ 1.75 g, NaCl 2.5 g, $K_2HPO_4$ 2 g, $MgSO_4$ 1.0 g, mono-sodium glutamate 7.5 g, $Na_2CO_3$ 3.71 g, $NH_4Cl$ 3.5g, $CaCl_2$ 0.01 g, per liter. Maximum carotenoid yield of 18.11 mg/L was measured by confirmatory experiment in liquid culture using 500 L fermenter.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.30 no.2
• /
• pp.17-28
• /
• 2022

The application of supplemental activated biochar pellet fertilizers (ABPFs) was evaluated by investigating key factors such as changes of surface paddy water and soil chemical properties and rice growth responses during the growing season. The treatments consisted of control, activated rice hull biochar pellet (ARHBP-40%), and activated palm biochar pellet (APBP-40%) applications. It was shown that the lowest NH₄⁺-N and PO₄^--P concentrations were observed in surface paddy water to the ARHBP-40%, while the NH₄⁺-N concentration in the control was abruptly decreased until 30 days after transplant in the soil. However, the lowest NH₄⁺-N concentration in the blended biochar application was 9.18 mg L^-1 at 1 day of transplant, but its ABPFs application was observed to be less than 1 mg L^-1 at 56 days after transplant. The lowest PO₄^--P concentration in paddy water treated ARHBP-40% ranged from 0.06 mg L^-1 to 0.08 mg L^-1 until 30 days after transplant among the treatments. For the paddy soil, the NH₄⁺-N concentration in the control was abruptly decreased from 177.7 mg kg^-1 to 49.4 mg kg^-1, while NO₃^--N concentration was highest, 13.2 mg kg^-1 in 14 days after transplant. The P₂O₅ concentrations in the soils increased from rice transplants until the harvesting period regardless of the treatments. The highest K₂O concentration was 252.8 mg kg^-1 in the APBP-40% at 84 days after transplant. For the rice growth responses, plant height in the control was relatively high compared to others, but grain yield was not significantly different between the control and ARHBP-40%. The application of ARHBP-40% can minimize nitrogen and phosphorous application rates into the agro-ecosystem.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.50 no.1
• /
• pp.59-65
• /
• 2024

For plasma cosmetics, it is important to ensure the long-term stability of plasma in the formulation. This study examined the suitability of containers for efficient plasma cosmetics development. By varying the surface area covered by the plasma, 4 cm², 25 cm², 75 cm², and 175 cm² containers were injected with cosmetic plasma, and the amount of nitric oxide (NO), the main active species of nitrogen plasma, was analyzed. As a result, the surface area and stability exposed to plasma tended to be inversely proportional, and it was most effective in a 4 cm² container. Furthermore, 25 mm, 40 mm, and 50 mm vials were treated with plasma, which resulted in relative long-term stability of NO at 25 mm, a smaller surface area of the container exposed to air. Water mist and stratified mist were selected as cosmetic formulations, and NO plasma was injected into the water layer to observe the changes in formulation properties and the state of the injected NO plasma. In both formulations, the amount of NO plasma injected was about 1.5 times higher in the water phase mist than in the stratified mist, and the stratified mist gradually decreased with time and was found to disappear after 3 weeks. The stability of the nitrogen plasma was studied at low temperature (4 ℃), room temperature (25 ℃), and high temperature (37 ℃, 50 ℃). As a result, it was found that the water mist did not affect the stability, but the stratified mist observed a color change in the oil phase layer. Overall, this study demonstrates the container suitability of nitrogen plasma and suggests the importance of ensuring the stability of injected nitrogen plasma in cosmetic formulations.