• Polymer(Korea)
• /
• v.38 no.2
• /
• pp.257-264
• /
• 2014

In this study, we modified silica nanoparticles with bis[3-(trimethoxysilyl)propyl]ethylenediamine (BTPED) silane coupling agent, which has two secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used acrylate group containing 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce polymerizable methacrylate groups by Michael addition reaction. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and liquid and solid state cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to understand the reactions between N-H groups of BTPED modified silica surface and acrylate groups of AHM monomer. We confirmed Michael addition reaction between BTPED modified silica and AHM completed in 2 hr reaction time. We also found increased methacrylate group introduction with increase of mol ratio of the acrylate group of AHM to N-H group of BTPED modified silica by increase of C=O peak area of measured FTIR spectra. These results were also supported by EA and solid state $^{13}C$ and $^{29}Si$ NMR results.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.11 no.2 s.54
• /
• pp.11-17
• /
• 2007

In current seismic design practice, the response modification factor (R-factor) is used as a factor to reduce the elastic base shear demand to the design force level. As is well-known, the R-factor is a committee-consensus factor and, as such, highly qualitative and empirical. The relationship between the R-factor and the connection rotation capacity available in a particular structural system has remained a missing link. In this paper, a rational procedure to evaluate the R-factor is proposed. To this end, the relationship between the available connection rotation capacity and the R-factor is defined and quantified using nonlinear pushover analysis. An RRS steel frame designed according to IBC 2000 was used to illustrate and verify the proposed procedure. Nonlinear time history analysis results indicated that the R-factor definition proposed in this study is generally conservative from design perspective.

• Korean Journal of Veterinary Research
• /
• v.33 no.4
• /
• pp.579-589
• /
• 1993

The regional distribution and the relative frequencies of endocrine cells were studied in nine portions of the blue fox GI tract, and the distribution pattern and cell types of the pancreativc endocrine cells were also studied in the pancreas by immunohistochemical method. Six kinds of immunoreactive cells were identified in the GI tract, and four kinds of immunoreactive cells were also identified in the pancreas. Although numerous 5-HT- and somatostatin-immunoreactive cells were seen throughout the GI tract, somatostatin- immunoreactive cells were a few in the intestine. Very numerous Gas/CCK-immunoreactive cells were restricted generally in the pyloric region and duodenum. Numerous glucagon-immunoreactive cells were found in the stomach except the pyloric region, and generally a few in the intestine. Moderate number of BPP-immunoreactive cells were found in the stomach except the pyloric region, and a few in the large intestine. Numerous porcine CG-immunoreactive cells were restricted to the cardiac and fundic region. In the pancreas, four types of pancreatic endocrine cells- somatostatin-, glucagon-, BPP- and insulin-immunoreactive- were identified in the pancreatic islet and exocrine portion. These results suggest that the regional distribution, the relative frequencies and cell types of the GEP endocrine cells in the GI tract and pancreas varies considerably among the species.

• Korean Journal of Veterinary Research
• /
• v.36 no.2
• /
• pp.297-303
• /
• 1996

The regional distribution and relative frequency of endocrine cells in the GIT of the snakehead, Channa(Oph icephalus) argus were studied immunohistochemically. Five kinds of endocrine cells and one kind of nerve cell were identified in this study. A few numbers of secretin-immunoreactive cells were restricted to the cardia and fundus of the stomach. Moti-lin- and GRP-immunoreactive cells were rare in the epithelium of the distal and proximal intestines. PYY-immunoreactive cells were found in a few number in the pyloric caeca and were rare in the distal intestine. Substance P-immunoreactive cells were distributed relatively numerous from the fundus to the distal intetsine. Also, their nerve cells were detected in occurrence in the lamina propria in the distal intestine. No neurotensin-, met-Enk- and GIP-immunoreactive cells were found in the GIT of the snakehead.

• Korean Journal of Veterinary Research
• /
• v.32 no.4
• /
• pp.523-529
• /
• 1992

The GEP endocrine cells of the African clawed toad, Xenopus laevis, were studied immunohistochemically. Five kinds of the endocrine cells were identified in this study A moderated number of 5-HT-immunoreactive cells were detected throughout the gastro intestinal tract, being almost uniform frequency. Gas/CCK -immunoreactive cells were restricted to the basal portion of the pyloric gland and among the duodenal mucosa. A rare glucagon-immunoreactive cells were weakly reacted in the fundic region of the stomach and observed in the exocrine portions of the pancreas. Somatostatine-immunoreactive cells were distributed throughout the gastrointestinal tract with except for the rectum, and not only the periphery of the islets but also the exocrine portions in the pancreas. No CGs- and insulin-immunoreactive cells were found in the gastrointestinal tract, whereas in the pancreas, the later was seen in the central region of the islets and the exocrine portions.

• International Area Studies Review
• /
• v.21 no.1
• /
• pp.181-200
• /
• 2017

This study investigates the impact of exchange rate and exchange rate volatility on the stock prices of eight industries from 2006 to 2015. The first and second exchange rate exposure of these eight industries is estimated with respect to four different exchange rates, namely the US dollar, Japanese yen, European currency unit, and British pound. In exchange rate exposure, stock prices in foods-beverages, paper-wood, electricity-gas, and banks industries are negatively related to exchange rate, whereas stock prices in electrical-electronic equp. and transport-equp. industries are positively related to exchange rate as expected. However stock price in machinery industry is negatively related to exchange rate, which is opposite to the expectation. Negative relationship is found between stock price in chemicals industry and exchange rate. In exchange rate volatility exposure, stock price in paper-wood industry is found to be negatively related to exchange rate volatility. Stock price in banks industry is also negatively related to exchange rate volatility. This result is opposite as expected, because banks are supposed to get more revenue by issuing derivatives related to foreign exchange when exchange rate volatility increases.

• Plant Journal
• /
• v.13 no.3
• /
• pp.36-46
• /
• 2017

In the reaction furnace of modified Claus process, chemical equilibrium reactions and kinetic reactions occur simultaneously. The main kinetic components are hydrogen ($H_2$), carbon monoxide (CO), carbonyl sulphide (COS) and carbon disulphide ($CS_2$). The equilibrium calculations, empirical correlations and sulfur recovery technology providers' (licensors) data for kinetic components (COS and $CS_2$) in the reaction furnace were analyzed to evaluate the amount of kinetic components by applying them to five different projects in which GS Engineering & Construction participated. Kinetic components ($H_2$ and CO) are also calculated and the results are analyzed to evaluate the impact of temperature in the reaction furnace and the waste heat boiler. Total required $O_2$ deviations for combustion in the reaction furnace are additionally shown, with and without side reactions. A full understanding of side reactions in the modified Claus process can help to improve sulfur recovery efficiency and optimize equipment design.

• Korean Journal of Veterinary Research
• /
• v.35 no.1
• /
• pp.39-44
• /
• 1995

Using immunohistochemical technique, three endocrine cell types were observed in the GIT of the Korean salamander, Hynobius leechii. BPP-immunoreactive cells were distributed from the pyloric region to the small intestine. A moderated number of somatostatin-immunoreactive cells were restricted to the pyloric region. 5-HT-immunoreactive cells were demonstrated throughout the GIT, reaching a peak in the pyloric region. The presence of BPP- and 5-HT-immunoreactive cells are identified for the first time in Hynobius leechii.

• Korean Journal of Veterinary Research
• /
• v.41 no.2
• /
• pp.133-138
• /
• 2001

The distributions and relative frequencies of the serotonin-immunoreactive cells were studied in dorsal, ventral, third and splenic lobes of developing chicken pancreas during embryonic periods (10 days of incubation to hatching) by immunohistochemical methods. The regions of pancreas were subdivided into three regions, exocrine, light and dark islets. Round and/or oval shaped serotonin-immunoreactive cells were detected in all four lobes. According to developmental stages, the types of lobes and the regions of pancreas, these immunoreactive cells were showed various distributions and relative frequencies. In exocrine portions, serotonin-immunoreactive cells were found in the splenic lobes at 13-14 days of incubation, in the third lobes from 10 days to 19 days of incubation, in the ventral lobes from 10 days of incubation to hatching and in the dorsal lobes from 11 days of incubation to hatching. In pancreatic islets, these cells were detected only in the dark islets of splenic lobes at 15 and 16 day of incubation with rare frequency. In conclusion, serotonin-immunoreactive cells decreased with developmental stages in all four lobes and their relative frequencies decreased with developmental stages.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.03a
• /
• pp.61-75
• /
• 2004

최근, 분리막의 응용에서 가장 활발하게 연구되고 있는 것이 반응과 분리를 동시에 수행하는 분리막 반응기(막 반응기)이다. 분리박 반응기 (membrane reactor)는 분리박과 반응기를 결합하여 분리와 반응의 단위공정을 하나로 결합하여 전체공정을 단순화하고 반응 효율을 높이고자 하는 새로운 기술이다. 반응과 분리를 동시에 수행할 수 있는 막 반응기를 도입하면, 생성물이 분리막을 이용하여 선택적으로 제거함으로서, 열역학적 평형을 뛰어넘는 전환율과 부반응물(by-product) 억제에 의한 반응 효율을 향상시킨다. (중략)