• Journal of the Korean earth science society
• /
• v.30 no.4
• /
• pp.409-426
• /
• 2009

In the four sedimentary cores from Yeoja Bay, the analyses of grain size, benthic foraminiferal species compositions, assemblages and statistics were carried out to investigate the effects of late Holocene sea-level change on benthic foraminifera. The core sediments were mainly composed of fine-grained silt and clay. The benthic foraminifera were classified into 27 species of 16 genera, 30 species of 21 genera, 50 species of 29 genera and 52 species of 29 genera in Core YC-1 to 4, respectively. In the result of cluster analysis, it seemed that Group 1 (Core YC-1 and 2) of representative A. beccarii assemblages was deposited in upper bay environment and Group 2 (Core YC-3 and 4) of representative E. clavatum-A. beccarii assemblages was deposited in inner bay environment affected by offshore water. In the result of species composition analysis, the production frequency of A. beccarii was gradually decreased from low layer to upper layer, whereas production frequency of E. clavatum and P.F./T.F. was gradually increased to upward. These change patterns appeared in benthic and planktonic foraminifera seemed to reflect the late Holocene sea-level rise in Yeoja Bay.

• Journal of the Korean earth science society
• /
• v.29 no.4
• /
• pp.328-340
• /
• 2008

To discriminate the provenance of shelf sediments in the western part off Jeju Island, the textual and elemental compositions were analyzed and compared with the sediments originating from Changjiang and Huanghe Rivers of China and the Korean (Keum) River. The sediments in the study area are composed of coarse silt with a mean pain size of $3.6{\sim}8.5{\phi}$ and their $CaCO_3$ contents ranged from 0.92 to 9.75 wt.%. The ratios of TOC over total nitrogen (TN) showed that the study area sediments contained more organic matters of marine origin than those of terrigenous origin. The high concentration of Fe/Al, Ti/Al and Mn/Al figures were found in the southwestern part near the Changjiang esturay, indicating that it seemed to result from the influence of the Changjiang River. The discrimination diagrams including Sc/Al vs Cr/Th, Th/Sc vs Nb/Co and Ti/Nb vs Th/Sc were thus used as provenance indicators to identify the sediment origins of the western part off Jeju Island. Based on these discriminated diagrams it clearly showed that most of the sediment in the western part were originated from the Huanghe River, but the sediments in the southwestern part near the Changjiang esturay might come from the Changjiang River. In contrast, the sediment samples of the northeastern part showed the higher figures than those of the river sediments and other regions, suggesting that the sediments in the western part off Jeju Island must be originated from diverse sources.

• Korean Chemical Engineering Research
• /
• v.43 no.3
• /
• pp.401-406
• /
• 2005

In this work, the effect of chemical treatment of multiwalled carbon nanotubes (MWNTs) on glass transition temperature (Tg), thermal stability, and dynamic viscoelastic behaviors of MWNTs-reinforced epoxy matrix composites has been studied by differencial scanning calorimeter (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) measurements. The MWNTs were chemically treated with 35 wt％ $H_3PO_4$ (A-MWNTs) or 35 wt％ KOH (B-MWNTs) solutions and the changes of surface properties of chemically treated MWNTs were examined by pH, acid and base values, Fourier transfer-infrared spectroscopy (FT-IR), and x-ray photoelectron spectroscopy (XPS) analyses. The chemical treatments based on acid and base reactions led to a significant change of surface characteristics and chemical compositions of the MWNTs, especially A-MWNTs/epoxy composites had higher thermal stability and dynamic viscoelastic properties than those of B-MWNTs and non-treated MWNTs/epoxy composites. These results were probably due to the improvement of interfacial bonding strength, resulting from the acid-base interaction and hydrogen bonding between the epoxy resins and the MWNT fillers.

• Korean Chemical Engineering Research
• /
• v.43 no.3
• /
• pp.419-424
• /
• 2005

Effect of temperature($22-32^{\circ}C$), pH(5-7) and medium composition on the mycelial growth for the submerged culture of Inonotus obliquus. The concentrations of glucose, starch, peptone, yeast extract, $K_2HPO_4$, $MgSO_4{\cdot}7H_2O$ and $CaCl_2$ were examined in the ranges of 30-120 g/L, 0-10 g/L, 0-20 g/L, 0-15 g/L, 0-2 g/L, 0-1.5 g/L and 0-0.5g/L, respectively. The maximum mycelial growth of Inonotus obliquus was obtained for $26-27^{\circ}C$ and pH 6. The concentrations of glucose, yeast extract and $CaCl_2$, which gave the maximum mycelial growth of Inonotus obliquus, were 70 g/L, 5 g/L and 0.1 g/L, respectively. In the cases of starch, peptone and $K_2HPO_4$, the mycelial growth of Inonotus obliquus increased with increasing the concentrations. However, as the concentration of $MgSO_4{\cdot}7H_2O$ increased, the mycelial growth of Inonotus obliquus decreased. The medium for maximum mycelial growth of Inonotus obliquus consisted of (per 1 L): glucose, 70 g; peptone, 5-20 g; starch, 10 g; yeast extract, 5 g; $K_2HPO_4$, 2 g and $CaCl_2$, 0.1 g.

• Korean Chemical Engineering Research
• /
• v.51 no.3
• /
• pp.335-341
• /
• 2013

Ammonia circulation reactor (ACR) was devised for the effective pretreatment of corn stover. This method is designed to circulate aqueous ammonia continuously so that it can reduce the chemical and water consumption during pretreatment. In this study, ammonia pretreatment with various reaction conditions such as reaction time (4~12 hour), temperature ($60{\sim}80^{\circ}C$), and solid:liquid ratio (1:3~1:8) was tested. Chemical compositions including solid remaining after reaction, lignin and carbohydrates were analyzed and enzymatic digestibility was also measured. It was observed that as reaction conditions become more severe, lignin removal was significantly affected, which was in the range of 47.6~70.6%. On the other hands, glucan and xylan losses were not substantial as compared to that of lignin. At all tested conditions, the glucan loss was not changed substantially, which was between 4.7% and 15.2%, while the xylan loss varied, which was between 7.4% and 25.8%. With (15 FPU-GC220+30 CBU)/g-glucan of enzyme loading, corn stover treated using ammonia circulation reactor for 8~12 hours resulted in 90.1~94.5% of 72-h glucan digestibility, which was higher than 92.7% of $Avicel^{(R)}$-101. In addition, initial hydrolysis rate (at 24 hour) of this treated corn stover was 73.0~79.4%, which was shown to be much faster than 69.5% of $Avicel^{(R)}$-101. As reaction time increased, more lignin removal and it was assumed that the enhanced enzymatic digestibility of treated biomass was attributed to the lignin removal.

• The Korean Journal of Elementary Counseling
• /
• v.9 no.2
• /
• pp.195-215
• /
• 2010

The purpose of this study is to have a preliminary study in order to develop a test which can comprehensively measure anxiety of elementary schoolchildren in middle grade. Following things are conducted to meet this task; first, to look into compositions of the anxiety of elementary schoolchildren in middle grade, to prepare proper questions to measure it and to develop a test; second, to look into whether such questions are fully understood by schoolchildren; third, to look into whether reliability and adequacy thereof are proper or not. Conclusion of the study is as follows; anxiety test of elementary schoolchildren in middle grade showed all the things related to general anxiety, social anxiety, study anxiety, examination anxiety, announcement anxiety. However, there were differences as per subordinate factor and detailed area. And reliability and adequacy of anxiety test for elementary schoolchildren in middle grade were appropriate. and such data could be valuably used for preparing anxiety test. To summarize the study result above, the test developed in this study supplements weak point of existing test instrument and reveals anxiety experienced by elementary schoolchildren in middle grade, and harmoniously composes all the kinds. It is meaningful that the test lowered applicable object to schoolchildren in middle grade who are in anxiety formation stage and also feel anxiety most strongly. In addition, it may be used usefully for living guidance and consultation to efficiently cope with anxiety by measuring base line regarding anxiety of individual schoolchildren in middle grade.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.553-558
• /
• 2010

This study was conducted to clarify the differences in rodents population densities between natural restored and red pine silvicultured forests after forest fire in Samcheok, Gangwon Province, Korea from March to December 2008. One ha size of 3 study plots were set up in each natural restored and silvicultured stand. We trapped the small rodents during 4 consecutive nights every 2 months in each stand. Understory coverage and number of shrub stems were higher in silvicultured stand than in natural restored stand. Coverage of overstory, suboverstory and midstory, number of tree stem, woody seedling stems and dead wood, and amount of coarse woody debris were higher in natural restored stand than in silvicultured stand. Six hundred eighty eight individuals of four species, such as Apodemus agrarius, A. peninsulae, Eothenomys regulus and Tamias sibiricus were captured in our study. Number of captured small rodents were higher in natural restored stand than in silvicultured stand. Also, species compositions were differed in both stands. The captured number of A. agrarius and A. peninsulae were most highest in April and December. E. regulus were shown higher number of captured in April and June, and T. sibiricus were in June and October. Removal of coarse woody debris and silvicultural practice would not be good for the inhabitation of small rodents. For the conservation of small rodents diversity, management of understory and canopy would be needed in forest fired area.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.5
• /
• pp.580-586
• /
• 2009

Black raspberry was fermented with or without seeds. Chemical characteristics were analyzed during wine fermentation. pH of black raspberry wine decreased in the early stage of the fermentation and thereafter increased. Total acidity increased until the 4th day of fermentation with little change afterwards. Both pH and acidity were not affected by the blending of the seeds. Sugar concentration decreased and alcohol concentration increased during the fermentation, and they were not influenced by the blending of the seeds. $L^*$, $a^*$, and $b^*$ values of black raspberry wines tended to increase until the 12th day of the fermentation and decreased or little changed thereafter. $L^*$, $a^*$, and $b^*$ values of black raspberry wines made from the fruits with seeds (BRSW) were lower than those of black raspberry wines without seeds (BRW) with no significance. Monomeric anthocyanin (MA) and polyphenol contents (PC) decreased during fermentation. MA was not significantly influenced by the blending of the seeds. PC in BRSW were higher than those in BRW with no significance. Alcohols were the major volatile components, and there were no differences between alcohol compositions in the two wines. There were also no differences in color, flavor, taste and overall acceptability in sensory characteristics. Similarity in the chemical characteristics between the BRSW and BRW suggests that development of black raspberry wine with seeds blended is possible.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.4
• /
• pp.525-528
• /
• 2009

In this study, phytosterol content and fatty acid composition of grape seeds from fourteen different cultivars produced in Korea were determined. Although the total phytosterol contents depended upon the cultivars, the major phytosterol was $\beta$-sitosterol (64.9$\sim$119.3 mg/100 g) in all samples. The fatty acid composition of the grape seeds were analyzed as palmitic (16:0, 6.8$\sim$16.8%), palmitoleic (16:1, 0.1$\sim$0.2%), stearic (18:0, 4.7$\sim$5.2%), oleic (18:1, 16.6$\sim$26.1%), linoleic (18:2, 16.6$\sim$20.1%), linolenic acid (18:3, 0.3$\sim$0.5%) and arachidic acid (20:0, 0.3$\sim$0.5%). Campbell early, the mainly produced and consumed cultivar in Korea, contained relatively high phytosterol content compared to other samples and high proportion of unsaturated fatty acids. Therefore, the seeds from Campbell early might be used for functional oil production and as food ingredients.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.5
• /
• pp.730-735
• /
• 2013

This study compared the nutritional components (proximate components, fatty acids, amino acids, minerals and vitamins) between genetically modified (GM) drought-tolerant rice and a parental rice cultivar (Ilmibyeo) as a non-GM control. Both GM and non-GM rices were grown and harvested in two different locations, Gunwi and Suweon in Korea. Proximate components (moisture, starch, protein, lipid, and ash contents) were similar between the drought-tolerant GM rice and the conventional non-GM rice. There were no significant differences between the GM and non-GM rice in most of their nutrient compositions, despite minor locational differences of some amino acids and minerals. These results indicate that transgenic rice with a genetically improved resistance to drought is equivalent to the parental rice cultivar without major changes in its chemical contents.