• Elastomers and Composites
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• v.37 no.3
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• pp.159-169
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• 2002

The improvement of flame retardancy of the foams based on NBR/GTR compounds was conducted by formulating various materials i.e. NBR, GTR, inorganic and phosphorus containing flame retardants, foaming agent, cross-linking agent and activator. The foaming properties, morphology, smoke density and flame retardancy of the specimens were investigated using SEM, LOI tester, smoke density control system and cone calorimeter. The phosphorus containing flame retardant reduces heat release rate, increases the limiting oxygen index and a char formation. The inorganic flame retardant increases the limiting oxygen index and reduces heat release rate with an increased CO yield by char formation, and smoke suppressing effect. The formed char seemed to intercept the oxygen transport and heat transfer into the core area. When the composition ratios of the compounds of NBR/GTR were $100{\sim}80/0{\sim}20 wt.%$, and the ratios of the rubbers/flame retardants were $1/1.55{\sim}3.60 wt.%$, we could developed foams with low heat release rate, high limiting oxygen index($28.0{\sim}39.3$), closed or semi-closed cell of uniformity and reasonable expandability($225{\sim}250 %$).

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.42-50
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• 2013

Since 1990's, a plywood for flooring base has gotten customers' demand. Costs of raw material and production increased because of changed environment of industry. Tropical timber such as Red Meranti (Shorea acuminate) used for raw material of the floor has been depleting beside countries in South Eastern Asia changed species of afforestation. As a result, it gets hard to secure good quality of raw material for plywood. Moreover plywood price is increased suddenly after earthquake in Japan. Eucalyptus (Eucalyptus globulus) in china has been using for raw material as a countermeasure of changed environment of industry. In this study, possibility of using flooring consisted of Eucalyptus veneer as crossband layers was checked by deflection experiments. Flooring consisted of Red Meranti was used for comparison. Two factors which impact on deflection are a type of density gradient and density difference between Long-grain veneer and Short-grain veneer. Red Meranti samples are M type of density gradient on the other hand Eucalyptus samples are W type of density gradient. The more samples have high density difference, the more deformation was checked. A sample which has big density difference between core and cross bands layer warp more also deform. Flooring was deformed smaller than plywood and samples which have big density difference was deformed more.

• Journal of the Mineralogical Society of Korea
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• v.17 no.1
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• pp.99-114
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• 2004

Mineralogical characteristics of fracture-filling minerals from deep borehole in the Yuseong area were studied for the radioactive waste disposal project. There are many fracture zones in the deep drill holes of the Yuseong granite, which was locally affected by the hydrothermal alteration. According to the results of hole rock analysis of drill core samples, $SiO_2$ contents are distinctly decreased, whereas $Al_2$$O_3$ and CaO contents and L.O.I. values are increased in the -90 m∼-130 m and -230 m∼-250 m zone, which is related to the formations of filling minerals. Fracture-filling minerals mainly consist of zeolite minerals (laumontite and heulandite), calcite, illite ($2M_1$ and 1Md polytypes), chlorite, epidote and kaolinite. The relative frequency of occurrence among the fracture-filling minerals is calcite zeolite mineral > illite > epidote chlorite kaolinite. Judging from the SEM observation and EPMA analysis, there is no systematic change in the texture and chemical composition of the fracture-filling minerals with depth. In the study area, low temperature hydrothermal alteration was overlapped with water-rock interactions for a long geological time through the fracture zone developed in the granite body. Therefore the further study on the origin and paragenesis of the fracture-filling minerals are required.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.454-462
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• 1997

Thermotropic block copolyester(TLCP-b-PBN) based on poly(tetramethylene 2,6-(naphthaloyldioxy)dibenzoates)(TLCP) and poly(butylene 2,6-naphthalate)(PBN) was synthesized by solution polycondensation and melt-blended with poly(ethylene 2,6-naphthalate)(PEN) for in-situ composites. The TLCP domains showed nematic behavior in melt. The composition of block copolymer was determined from $^1H-NMR$ spectroscopy. The DSC thermogram of block copolymer revealed the presence of two major melting transitions, corresponding to the separete melting of PBN and TLCP domains. The glass transition temperature(Tg) of the PEN in the blends decreased with increasing the content of TLCP-b-PBN and the TLCP-b-PBN acted as a nucleating agent for the matrix polymers. In the 20% TLCP-b-PBN blend, well oriented TLCP fibriles were observed at temperature above the melting point of the PEN by optical microscopy. By scanning electron micrographs of cryogenically fractured surfaces of extruded blends, the TLCp domains were found to be finely and uniformely dispersed in 0.15 to $0.2{\mu}m$ size. Interfacial adhesion between the TLCP and matrix polymer was seemed to be good. Under certain condition TLCP formed a fiver structure in the PEN matrix, with thin oriented TLCP fibril in the skin region and spherical TLCP domains in the core.

• Journal of Gastric Cancer
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• v.18 no.2
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• pp.118-133
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• 2018

Purpose: Exercise intervention after surgery has been found to improve physical fitness and quality of life (QOL). The purpose of this study was to investigate the feasibility and effects of a postoperative recovery exercise program developed specifically for gastric cancer patients (PREP-GC) undergoing minimally invasive gastrectomy. Materials and Methods: Twenty-four patients treated surgically for early gastric cancer were enrolled in the PREP-GC. The exercise program comprised sessions of In-hospital Exercise (1 week), Home Exercise (1 week), and Fitness Improvement Exercise (8 weeks). Adherence and compliance to PREP-GC were evaluated. In addition, body composition, physical fitness, and QOL were assessed during the preoperative period, after the postoperative recovery (2 weeks after surgery), and upon completing the PREP-GC (10 weeks after surgery). Results: Of the 24 enrolled patients, 20 completed the study without any adverse events related to the PREP-GC. Adherence and compliance rates to the Fitness Improvement Exercise were 79.4% and 99.4%, respectively. Upon completing the PREP-GC, patients also exhibited restored cardiopulmonary function and muscular strength, with improved muscular endurance and flexibility (P<0.05). Compared to those in the preoperative period, no differences were found in symptom scale scores measured using the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) and Quality of Life Questionnaire-Stomach Cancer-Specific Module (QLQ-STO22); however, higher scores for global health status and emotional functioning were observed after completing the PREP-GC (P<0.05). Conclusions: In gastric cancer patients undergoing minimally invasive gastrectomy, PREP-GC was found to be feasible and safe, with high adherence and compliance. Although randomized studies evaluating the benefits of exercise intervention during postoperative recovery are needed, surgeons should encourage patients to participate in systematic exercise intervention programs in the early postoperative period (Registered at the ClinicalTrials.gov, NCT01751880).

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.941-951
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• 2012

The changes of forest habitats and maeulsoops(village forests) in Jinan-gun, Jeollabuk-do, South Korea are examined using landscape indices and morphological pattern analysis, and their landscape-ecological implications on conserving biological diversity are presented. We used FRAGSTATS and GUIDOS software, as well as land cover maps(of 1989 and 2006) to analyze the spatial and temporal patterns of habitat composition and configuration in surrounding landscapes of 34 representative maeulsoops and Jinan-gun. The results showed decreases in the amount of core habitats and corridors and habitat connectivity at a regional scale since 1989. In addition, multi-scale habitat analysis at a focal scale revealed that the structural and functional connectivity between forest habitats surrounding maeulsoops of the year 2006 was lower than that of the year 1989. In order to reduce forest fragmentation and to enhance the connectivity among habitats, it is necessary to provide the additional habitat corridors as well as preserving existing corridors and surrounding landscapes of maeulsoops. We also suggest that a combination of landscape indices and morphological spatial pattern analysis can provide an effective tool to assess the habitat functions and configuration in a rapidly changing landscape.

• Korean Journal of Plant Taxonomy
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• v.37 no.1
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• pp.41-59
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• 2007

This study was to establish the floristic composition of northern region in Gyeonggi-Province area($126^{\circ}45^{\prime}-127^{\circ}37^{\prime}E$, $37^{\circ}31^{\prime}-38^{\circ}17^{\prime}N$). This work was investigated from April, 1988 to October, 2004. The flora of vascular plants of northern region in Gyeonggi-Province were consisted of total 2,030 taxa; 145 families, 656 genera, 1,611 species, 7 subspecies, 320 varieties, 1 subvarieties and 91 formae. Among them, Korean endemic species were composed of 46 families, 85 genera, 84 species, 35 varieties, 1 subvarieties, and 18 formae, total 138 taxa. The rare and endangered plants based on floral region indicated by Ministry of Environment were 416 taxa; V rank species 18 taxa, IV rank species 79 taxa, III rank species 111 taxa, II rank species 80 taxa, I rank species 128 taxa. Also the naturalized plants were 114 species, correspond to 39.7% of among total 287 species appeared in South Korea. the result of PCA, Gwangju mountain chain at northern region of Gyeonggi-Province has rich and diverse vascular plants, and there are many Korean endemic, rare and endangered plants. therefore Gwangju mountain chain must be the core axis in for conserving the plant biodiversity and richness.

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.163-174
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• 2006

The $Ph{\acute{e}}bus$ FP project is an international reactor safety project. Its main objective is to study the release, transport and retention of fission products in a severe accident of a light water reactor (LWR). The FPT4 test was performed with a fuel debris bed geometry, to look at late phase core degradation and the releases of low volatile fission products and actinides. Post Test Analyses results indicate that releases of noble gases (Xe, Kr) and high-volatile fission products (Cs, I) were nearly complete and comparable to those obtained during $Ph{\acute{e}}bus$ tests performed with a fuel bundle geometry (FPT1, FPT2). Volatile fission products such as Mo, Te, Rb, Sb were released significantly as in previous tests. Ba integral release was greater than that observed during FPT1. Release of Ru was comparable to that observed during FPT1 and FPT2. As in other $Ph{\acute{e}}bus$ tests, the Ru distribution suggests Ru volatilization followed by fast redeposition in the fuelled section. The similar release fraction for all lanthanides and fuel elements suggests the released fuel particles deposited onto the plenum surfaces. A blockage by molten material induced a steam by-pass which may explain some of the low releases. The revaporisation testing under different atmospheres (pure steam, $H_2/N_2$ and steam /$H_2$) and up to $1000^{\circ}C$ was performed on samples from the first upper plenum. These showed high releases of Cs for all the atmospheres tested. However, different kinetics of revaporisation were observed depending on the gas composition and temperature. Besides Cs, significant revaporisations of other elements were observed: e.g. Ag under reducing conditions, Cd and Sn in steam-containing atmospheres. Revaporisation of small amounts of fuel was also observed in pure steam atmosphere.

• The Journal of the Petrological Society of Korea
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• v.14 no.3 s.41
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• pp.127-140
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• 2005

The Samyuri area of Jeoksang-myeon, Muju-gun at the Middle Yeongnam Massif consists of granitic gneiss, porphyroblastic gneiss and leucocratic gneiss, which correspond to Precambrian Wonnam Series. Here we discuss a geochemical implication of the data based on major element composition, trace element, rare earth element (REE), Sm-Nd and Rb-Sr isotope systematics of the boring cores in the granite gneiss area. The boring cores are granitic gneiss (including biotite gneiss) and amphibolite. The major and trace element compositions of granitic gneiss and amphibolite suggest that the protolith belongs to TTG (Tonalite-Trondhjemite-Granodiorite) and tholeiitic series, respectively. Chondrte-normalized REE patterns vary in LREE, HREE and Eu anomalies. The granitic gneiss and amphibolite have Sm-Nd whole rock age of $2,026{\pm}230(2{\sigma})$ Ma with an initial Nd isotopic ratio of $0.50979{\pm}0.00028(2{\sigma})$ (initial ${\epsilon}_{Nd}=-4.4$), which suggests that the source material was derived from old crustal material. Particularly, this initial ${\epsilon}$ Nd value belongs to the range of the geochemical evolution of Archean basement in North-China Craton, and also corresponds to the initial Nd isotope evolution line by Lee et al. (2005). In addition, chondrite-normalized REE pattern and initial Nd value of amphibolite are very similar to those of juvenile magma in crustal formation process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.323-330
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• 1994

Benzyladenine(BA) and Diphenylurea(DPU) at 10ppm level were foliar-applied one to three times at an interval of 10 days from heading stage of rice variety, Dongjinbyeo. One time treatment of both cytokinins did not delayed leaf senescence substantially, but consecutive treatments of two to three times markedly retarded leaf senescence. Leaf senescence retarding effects were greater in BA than DPU. Ripened grain ratio, grain weight and grain yield were not improved by the treatments. BA treatments increased the percentage of green and white belly kernels with no effects on opaque and white core kernels. BA and DPU treatments did not altered amylose content, but BA treatments significantly decreased protein content of polished rice. Consecutive treatments of BA and DPU twice or three times at an interval of 10 days from heading increased oil content by 30 to 78% as compared to non-treated control, but one time treatment at any stage did not enhance it of polished rice. Fatty acid composition was slightly altered in favor of unsaturated fatty acid by BA and DPU treatments.