• Korean Journal of Soil Science and Fertilizer
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• v.38 no.6
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• pp.313-320
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• 2005

Various by-product composts are applied in alpine farmland, and some of them generate many problems especially when they are not completely composted. The objective of this study was to investigate the physicochemical and spectroscopic properties of by-product composts used in Gangweon alpine uplands. Average organic matter content, C/N ratio and NaCl content in 3 species of registered composts were 33%, 13 and 0.8%, respectively, and the general quality were better than the guideline of by-product compost. Odor and contents of $NH_3$ and $CO_2$ in the registered composts were relatively lower than those in the unregistered composts. Among the 13 unregistered composts tested in this experiment, 3 species contained organic matter content less than 25%, 5 species had C/N ratio less than 10, and 8 species contained NaCl exceeded the acceptable level. Eight species in the unregistered composts contained more than 50% of water. Contents of heavy metals in both the registered and unregistered composts were lower than the acceptable level. In spectroscopic property analysis, registered composts were Band P types, and unregistered composts were Rp and P types.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1164-1173
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• 1996

Treating methods and characteristics of waste from a nuclear fuel powder conversion plant were studied. To recovery or treat a trace uranium in liquid waste, the ammonium uranyl carbonate(AUC) filtrate must be heated for $CO_2$ expelling, essentially. Uranium content of final treated waste solution from fuel powder processes for a heavy water reactor(HWR) could be lowered to 1 ppm by the lime treatment after the ammonium di-uranate(ADU) precipitation by simple heating. Otherwise, in case of the waste from fuel powder processes for a pressurized light water reactor(PWR), it is result in 0.8 ppm as a form of uranium peroxide such as $UO_4{\cdot}2NH_4F$ compounds. Optimum condition was found at $101^{\circ}C$ by the simple heating method in case of HWR powder process waste. And in case of PWR powder process waste, optimum condition could be obtained by precipitating with adding hydrogen peroxide and adjusting at pH 9.5 with ammonia gas at $60^{\circ}C$ after heating the waste In order to expelling $CO_2$. As the characteristics of recovered uranium compounds, median particle size of ADU was increased with pH increasing in case of HWP waste. Also, in case of uranium proxide compound recovered from PWR waste, the property of $U_3O_8$ power obtained after thermal treatment in air atmosphere was similar to that of the powder prepared from AUC conversion plant.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.80-86
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• 2017

In this study, nitrogen functional groups were introduced on graphite fiber (GF) to modify their electrical properties, and heating properties were investigated according to the treatment conditions. GF was prepared by a thermal solid-state reaction at $200^{\circ}C$ for 2 h. Surface properties of the nitrogen doped GF were examined by XPS, and its resistance and heating temperature were measured using a programmable electrometer and thermo-graphic camera, respectively. The XPS result showed that the nitrogen functional groups on the GF surface were increased with increasing of urea contents, and the heating property of the GF was also improved as nitrogen functional groups were introduced. The maximum heating temperature of GF treated by urea was $53.8^{\circ}C$ at 60 V, which showed 55% improved heating characteristics compared to that of non-treated GF. We ascribe this effect to introduced nitrogen functional groups on the GF surface by thermal solid-state reaction, which significantly affects the heating characteristics of GF.

• Polymer(Korea)
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• v.30 no.2
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• pp.140-145
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• 2006

The mort commonly available substrate material is glass in the display fibrication process. However, glass is not desirable due to its heaviness and fragility. Recently, plastics such polysulfone (PSF), polyethesulfone (PES), polycarbonate (PC), polyethylene terephthalate (PET) and cyclic olefin polymers (COP) have been investigated to replace glass as a substrate material for display fibrication. Plastic substrates are advantageous in that they are lightweight, huh impart resistance, flexibility, and ability for roll to roll manufacturing process. But many plastics have poor chemical resistance in organic solvent. The chemica resistance is also lequired because they are exposed to solvents for various chemical treatments din the manufacturing process. So, we have an interest in the chemical modification of PSF to improve chemical resistance. We introduced crosslinkable imide moieties using chloromethylation method for the modification of PSF which could be overcome above shortcomings for display substrate based on plastic film. We prepared the cross-linked polysulfone films which were represented chemical resistance in HeOH, THF, DMSO and NMP. The thermal properties were measured by TGA, DSC and TMA. As the results, we have confirmed to enhance of the thermal property. They had low coefficient of thermal expansion (CTE) which decreased to 15% and had increased $T_g\;from\;180^{\circ}C\;to\;252^{\circ}C$. Cross-linked polysulfone films with imide side-chain had good optical properties and chemical resistance so that they could be used as flexible display substrate.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.562-566
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• 2012

A novel design of tubular segmented-in-series(SIS) solid oxide fuel cell (SOFC) sub module was presented in this paper. The tubular ceramic support was fabricated by the extrusion technique. The NiO-YSZ anode and the yttria-stabilized zirconia (YSZ) electrolyte were deposited onto the ceramic support by dip coating method. After sintering at $1350^{\circ}C$ for 5 h, a dense and crack-free YSZ film was successfully fabricated. Also, the multi-layered cathode composed of LSM-YSZ composite, LSM and LSCF were coated onto the sintered ceramic support by dip coating method and sintered at $1150^{\circ}C$. The performance of the tubular SIS SOFC cell and sub module electrically connected by the Ag-glass interconnect was measured and analysed with different fuel flow and operating temperature.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.421-428
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• 1996

The occurrence, optical property, chemical composition, crystal structure and formation environments of the phillipsite within deep-sea manganese nodules were systematically investigated in this study. Phillipsite in manganese nodules occurs in nucleus of nodules along with consolidated bottom sediments, weathered volcanic debris, and interstitial grains in the each layer of manganese encrusts. Phillipsite is predominantly pseudomorphs of volcanic shards, and occurs as white to pale yellow in color lath-shaped and equant crystals. These show aggregations of prismatic, blocky, and bladed of 2 to $20{\mu}m$ long, and 2 to $5{\mu}m$ thick. The simplified average chemical formula of phillipsite is $({Ca_{0.1}Mg_{0.3}Na_{1.1}K_{1.5}})_3{(Fe_{0.3}Al_{4.2}Si_{11.8})O_{32}{\cdot}10H_2O}$ with a very siliceous and alkalic. The $Si/(Al+Fe^{+3})$ ratio is 2.37 to 2.78 and alkalis greatly exceed the divalent exchangeable cations, and Na/K ratio is 0.59 to 0.81. The phillipsite is monoclinic ($P2_l/m$) with the unit-cell parameters, $a=10.005{\AA}$, $b=14.129{\AA}$, $c=8.686{\AA}$, ${\beta}=124.35^{\circ}$, and $V=1013.6{\AA}^3$. Phillipsites in manganese nodules formed apparently authigenically at a temperature less than $10^{\circ}C$, and they crystallized at a pressure of less than 0.7 kb, and pH of about 8 in deep-sea environments.

• Korean Journal of Head & Neck Oncology
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• v.25 no.1
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• pp.3-7
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• 2009

Background and Objectives : Panax ginseng C.A. Meyer is a medical plant that has been widely utilized as a tonic and nutritional agent since ancient times in Korea. Ginseng has anti-metastatic property of cancer and immunomodulating activity. The novel acidic polysaccharide compound(MB40) was isolated from the leaves of Panax ginseng C.A. Meyer. To determine immunomodulating activities of MB40, we evaluate anti-cancer and anti-metastatic effects of MB40 in tumor bearing immune competent mice. Material and Methods : C3H mice were divided into three equal groups(Cisplatin treatment group, MB40 treat-ment group, Cisplatin and MB40 treatment group) and were transplanted SCC(Squamous Cell Carcinoma) cells(2${\times}$106) to the lateral side of abdomen. From day 4 after transplantation, MB40 was administrated at dose of 10mg/kg, respectively, every other day by intratumoral injection. Cisplatin was systemically administrated at doses of 1mg/kg, respectively, every week by intraperitoneal injection. Results : 5 days after administration, tumors can be palpated in every mice group. After 13 days of administration, the mice group to which MB40 were administrated exhibited reduction in tumor size respectively, compared to cisplatin group. Overall status of mice such as body weight and activity were superior in MB40 group than cisplatin group. Conclusion : The result of this study indicates MB40 may have significant therapeutic effect and decreases complications induced by systemic chemotheraphy. MB40 may be developed as a novel and potent immunotropics to improve the cell immune system and anti-cancer drug for the treatment of cancer patients in head and neck squamous cell carcinoma.

• The Korean Journal of Community Living Science
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• v.26 no.2
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• pp.261-274
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• 2015

Although fasting programs have recently attracted close attention because of benefits of detoxification, few studies have examined these programs. This study investigates the effects of a modified juice-based fasting program on lipid metabolism. A total of 33 volunteers fasted for 10 days and participated in program lectures, exercise programs, water bath regimens, and enemas. Pre- and post-program blood samples were obtained to evaluate lipoprotein levels. A paired t-test was conducted using SPSS 18.0. Changes in the lipid profile were observed during the juice-based fasting program and attending 3 degrees. All lipid profiles decreased significantly, including total cholesterol (TC) (p<0.001), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) (p<0.05). Program participation was documented by assessing attendance levels as high, moderate, and low. TC decreased significantly in all programs and levels (p<0.05), TG decreased proportionally only in enemas according to the attending degree: high (48 %), moderate (20 %), and low (10 %). HDL-C decreased at all low levels, but moderate exercise ($53.8{\pm}12.5mg/dL$ to $55.6{\pm}10.2mg/dL$) and a high enema ($54.9{\pm}14.1mg/dL$ to $55.0{\pm}9.4mg/dL$) showed small increases. The antioxidant property of the juice-based fasting program in terms of the blood vessel, enemas, and exercise played an important role in preventing cardiovascular disease from increased levels of HDL-C. These results suggest that juice-based fasting and combined lifestyle programs may help improve lipid metabolism and protect against dyslipidemia.

• Polymer(Korea)
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• v.32 no.4
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• pp.359-365
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• 2008

We have fabricated a novel thermo-responsive nanofibrous surfaces by grafting PIPAAm by electron beam irradiation onto poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) nanofibrous mats. The electrospun PHBV nanofiber structures revealed randomly aligned fibers with average diameter of 400 nm. Increased atomic percent of nitrogen was observed on the PIPAAm-grafted PHBV mats after electron beam irradiation determined by ESCA. The amounts of PIPAAm-grafted onto PHBV films were $6.49{\mu}g/cm^2$ determined by ATR-FTIR. The PIPAAm-grafted surfaces exhibited decreasing contact angles by lowering the temperature from 37 to $20^{\circ}C$, while ungrafted PHBV surfaces had negligible contact angle change. This result indicates that PIPAAm surfaces, which are hydrophobic at the higher temperature, became markedly more hydrophilic in response to a temperature reduction due to spontaneous hydration of the surface-grafted PIPAAm. Thermo-responsive nanofibers showed good tissue compatibility. Cultured cells were well detached and recovered from the surfaces by changing culture temperature from 37 to $20^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1097-1102
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• 2002

Hydroxyapatite(HAp) powders were synthesized by wet-precipitation precess using $Ca(NO_3)_2{\cdot}4H_2O$ and $(NH_4)_2HPO_4$ and homogeneous composites of four type were prepared by mixing of synthetic HAp and Polyacrylic Acid(PAA). Ca/P ratio of synthetic HAps was determined using ICP analysis and the thermal property of HAp/PAA composites were investigated by TGA. Good crystalline HAp was obtained at pH 11 and $60{\circ}C$. The ratio of Ca/P in synthetic HAps was quantified in a range of 1.35~1.49, from which Ca-deficient HAp was obtained. The specific surface area of HAp/PAA composite increased with increasing the content of PAA and the weight loss of HAp/PAA composite at $800{\circ}C$ decreased in a range of 3.5~9.6% due to the degradation of PAA binder. From FT-IR analysis of HAp/PAA composite, it was confirmed that the ionic bond between ion of HAp and carboxyl group of PAA was formed.