• Journal of Life Science
• /
• v.18 no.3
• /
• pp.409-413
• /
• 2008

The occurences of proteins relating to Antheraea pernyi arylphorin in haemolymph, fat body, integument, midgut and silkgland of the wild silkmoths, Antheraea yamamai, Antheraea pernyi, Samia cynthia pryeri and Actias gnoma in the 5th larval instar were investigated by immunoblot analysis using mouse polyclonal antibody against A. pernyi arylphorin as probe. In A. yamamai, A. pernyi, S. cynthia pryeri and A. gnoma, the major immunoreactive antigenic proteins with a molecular weight of 80 KDa against the antisera of the A. pernyi arylphorin were clearly observed in the haemolymph, but in the integument, fat body, midgut and silkgland of the corresponding wild silkmoths the presence of the immunoreactive proteins were very variable. These results suggest that the A. pernyi arylphorin has almost same immunological identity with those of the wild silkmoths, A. yamamai, S. cynthia pryeri and A. gnoma though the distribution of the corresponding antigenic arylphorins is different according to the tissues of the wild silkmoths.

• Korean Journal of Food Science and Technology
• /
• v.29 no.4
• /
• pp.648-656
• /
• 1997

Thermal treatment of soymilk residue was carried out at 140, 150, and $160^{\circ}C$ for possible use as a raw material for dietary fiber, and some physicochemical properties of the extracts were investigated. Soluble dietary fiber(SDF) content of the extracts prepared under optimal conditions was more than 30% suggesting the conversion of insoluble dietary fiber to SDF. The main sugar components of the extracts were glucose, galactose, and arabinose. Analysis of the moelcular weight distribution by high performance size exclusion chromatography revealed that the proportion of high molecular weight fraction decreased and that of middle-sized polymer increased as the extraction temperature increased. The viscosity of aqueous solution of the extracts decreased with an increase in extraction temperature, but showed no trend as pH changed. The solubility increased with extraction temperature showing the highest at $160^{\circ}C$. The extract at $140^{\circ}C$ had the biggest calcium-binding capacity, which correlated with the changes in viscosity.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.33 no.3
• /
• pp.72-83
• /
• 2015

A plant diversity, which consists of indigenous plant community with Orientla thuja community (Natural monument no. 1) in Dodong, Daegu, is identified and analyzed as ecological characteristic to consider worth plants and vegetation resource of the region. The vascular plants of Thuja orientalis community were listed as 219 taxa (3.7% of all 4,881 taxa of Korean vascular plants); 67 families, 147 genera, 199 species, 16 varieties, and 4 forms. Vulnerable species (VU) and least concerned species (LC) were recorded based on IUCN standard; Koelretueria paniculata (VU), Thuja orientalis (LC), and Exochorda serratifolia (LC). Although the study site is a non-limestone area, a total of 15 taxa of calciphilous plants were identified; Cheilanthes argentea, Hypodematium glandulosopilosum, Asplenium retamuraria, Thuja orientalis, Spiraea blumei, Smilax sieboldii, etc. A total of 4 taxa endemic plants were identified; Prunus mandshurica for. barbinervis, Lespedeza maximowiczii var. tomentella, Forythia koreana (artificial origin), and Veronica pyrethrina. Among the list, 8 taxa of naturalized plants were identified; Fallopia dentatoalalta, Rumex crispus, Nasturtium officinale, Bidens frondosa, Erigeron annuus etc. Naturalization rate (NR) was 3.6%, of all 219 taxa of vascular plants and urbanization index (UI) was 2.2% of all 321 taxa of naturalized plants. Thuja orientalis occupies a lot of indigenous landscape in this study area which is the southern-limited part of a natural distribution where it can survive. The T. orientalis community, where indigenous plants have formed a characterful species composition based on habitat, has been confirmed as a worth national vegetation resource in an indigeous flora. It has been considered of plans for persistent conservation.

• Korean Journal of Environment and Ecology
• /
• v.27 no.5
• /
• pp.550-560
• /
• 2013

This study was investigated the morphological characters, secondary sexual dimorphism, and habitat patterns of Korean Rattus animals collected on Jeju Island from April 2005 to October 2012. Two wild rat species, namely R. norvegicus and R. tanezumi were identified on Jeju Island based on morphological characteristics and molecular data; however, R. rattus, which had recorded formerly, was not found in this study. Individuals of R. norvegicus were captured from urban, rural, and natural habitats, while those of R. tanezumi were specially found in animal farms and the surrounding areas. Comparing of morphological characters of two species, R. norvegicus had a shorter tail and ears than R. tanezumi (p<0.05), and the ratios of tail length and ear length to those of head-body length showed significantly differences between two species (p<0.05). The body weights (BW) of urban populations of R. norvegicus were significantly heavier than those of rural populations (p<0.05). No secondary sexual dimorphism was found in R. norvegicus, but females of R. tanezumi showed heavier BW than those of males (p<0.05). These findings suggest that it is necessary to revise the records for the existence of R. tanezumi and to confirm the animal fauna and elucidate the distribution and ecological characteristics from further studies using extensive sampling and detailed investigations on Jeju Island and also on the Korean Peninsula.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.546-546
• /
• 2008

Copper (Cu) Chemical mechanical polishing (CMP) has been an essential process for Cu wifing of DRAM and NAND flash memory beyond 45nm. Copper has been employed as ideal material for interconnect and metal line due to the low resistivity and high resistant to electro-migration. Damascene process is currently used in conjunction with CMP in the fabrication of multi-level copper interconnects for advanced logic and memory devices. Cu CMP involves removal of material by the combination of chemical and mechanical action. Chemicals in slurry aid in material removal by modifying the surface film while abrasion between the particles, pad, and the modified film facilitates mechanical removal. In our research, we emphasized on the role of chemical effect of slurry on Cu CMP, especially on the effect of amine functional group on removal rate selectivity between Cu and Tantalum-nitride (TaN) film. We investigated the two different kinds of complexing agent both with amine functional group. On the one hand, Polyacrylamide as a polymer affected the stability of abrasive, viscosity of slurry and the corrosion current of copper film especially at high concentration. At higher concentration, the aggregation of abrasive particles was suppressed by the steric effect of PAM, thus showed higher fraction of small particle distribution. It also showed a fluctuation behavior of the viscosity of slurry at high shear rate due to transformation of polymer chain. Also, because of forming thick passivation layer on the surface of Cu film, the diffusion of oxidant to the Cu surface was inhibited; therefore, the corrosion current with 0.7wt% PAM was smaller than that without PAM. the polishing rate of Cu film slightly increased up to 0.3wt%, then decreased with increasing of PAM concentration. On the contrary, the polishing rate of TaN film was strongly suppressed and saturated with increasing of PAM concentration at 0.3wt%. We also studied the electrostatic interaction between abrasive particle and Cu/TaN film with different PAM concentration. On the other hand, amino-methyl-propanol (AMP) as a single molecule does not affect the stability, rheological and corrosion behavior of the slurry as the polymer PAM. The polishing behavior of TaN film and selectivity with AMP appeared the similar trend to the slurry with PAM. The polishing behavior of Cu film with AMP, however, was quite different with that of PAM. We assume this difference was originated from different compactness of surface passivation layer on the Cu film under the same concentration due to the different molecular weight of PAM and AMP.

• Journal of the Korean Chemical Society
• /
• v.62 no.4
• /
• pp.288-298
• /
• 2018

In this study, we surveyed pre- and post-perceptions of fourteen science teachers related to the atmosphere composition of molecules with different masses by the developed test. As a result of the test, the teachers were classified into two types of thoughts; One of them is considered the atmosphere to be a homogeneous solution, and the other is a thought that the composition ratio of the atmosphere was not homogeneous considering the different weights of particles. The two types were reclassified into three categories; one of them is considering large gravity effect, another is considering small gravity effect, and the other is considering medium scale gravity effect. Total six types of thoughts were found from the pre-test. After introducing crosscutting concepts which are related to the composition of atmosphere. The teachers discussed the phenomena with the molecular motion by weights of atoms and temperature, the homogeneity of the solution of air in chemistry domain. They also discussed with the relationship between mass and gravity and distance in physics domain. And the discussion included distribution of the atmosphere, convection phenomena, etc. After the discussion, the teachers changed their pre-conceptions to post-concoctions considering combined perspectives of gravity, mass, temperature, altitude etc. Through these changes, we are able to confirm the importance of crosscutting concepts covered in various disciplines. In the integrated science, we should help teachers to provide students with these types of thinking in order to form a coherent world-view and to carry out inquiry thinking as an intellectual tool.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.34 no.3
• /
• pp.317-324
• /
• 2010

Metal-supported solid oxide fuel cells (SOFCs) have been developed to commercialize SOFCs. This new type of SOFC has high mechanical strength, but its mass transfer rate may be low due to the presence of a contact layer. In this study, the mass transfer characteristics of an anode-supported SOFC and a metal-supported SOFC are studied by performing numerical simulation. Governing equations, electrochemical reactions, and ceramic physical-property models are determined simultaneously; molecular diffusion and Knudsen diffusion are considered in mass transport analysis of porous media. The experimental results are compared with simulation data to validate the results of numerical simulation. The average current density of the metal-supported SOFC is 23% lower than that of the anode-supported SOFC. However, because of the presence of the contact layer, the metal-supported SOFC has a more uniform distribution than the anode-supported SOFC.

• Polymer(Korea)
• /
• v.27 no.1
• /
• pp.9-16
• /
• 2003

Ipriflavone (IP) stimulates proliferation and differentiation of osteoblast and also enhances calcitonin secretion in the presence of estrogen. Poly(lactide-co-glycolide) (PLCA) due to its controllable biodegradability and relatively good biocompatibility is one of the most significant candidates for the study of drug controlled release system. In this study, IP-loaded PLGA microspheres (MSs) was prepared by using conventional O/W solvent evaporation method. The size of MSs was in the range of 5~200 $mu extrm{m}$. The morphology of MSs was characterized by SEM. And, in vitro release amounts of IP were analyzed by HPLC. The highest encapsulation efficiency were obtained by using gelatin and polyvinyl alcohol (PVA) as emulsifiers. The morphology, size distribution, and in vitro release pattern of MSs were changed by several preparation parameters such as molecular weights (8, 20, 33 and 90 kg/mol), polymer concentrations (2.5, 5, 10 and 20%), emulsifier types (PVA, gelatin and Tween 80), initial drug loading amount (5, 10, 20 and 30%) and stirring speed (250, 500 and 1000 rpm). The release of IP in vitro was more prolonged over 30 days, with close to zero-order pattern by controlling the preparation parameters. The physicochemical properties of IP-loaded PLGA MSs were investigated by XRD and DSC.

• Korean Journal of Food Science and Technology
• /
• v.16 no.2
• /
• pp.228-234
• /
• 1984

A partial hydrolysis of soybean protein isolate was carried out by using pepsin and trypsin. The degree of hydrolysis was evaluated by chemical analysis, viscometric measurements and gel electrophoresis. The functional properties of the hydrolyzates such as flow behavior, emulsion properties and foaming properties were evaluated. A selective hydrolysis of 11S protein fraction by pepsin was observed from the SDS-PAG electrophoresis. The changes in the molecular weight distribution by different conditions of enzyme hydrolysis were evaluated. The changes in the intrinsic viscosity of the protein hydrolylate by reaction time were highly correlated to the contents of TCA soluble protein and 0.03 M $CaCl_2$ soluble nitrogen. The degree of hydrolysis ($DH_{TCA}$, $DH_{Ca}$) were used to evaluate the effect of enzyme treatment on the functional properties of the hydrolyzate. The apparent viscosity and emulsion capacity and stability of the protein solution decreased as DH increased, while the foaming capacity increased linearly with the increasing DH.

• Korean Journal of Microbiology
• /
• v.54 no.2
• /
• pp.98-104
• /
• 2018

Naegleria fowleri and Acanthamoeba spp. are free-living amoebas that are widely distributed in natural environments. Although uncommon, infection with these protozoans can cause fatal disease in humans and animals. In this study, in order to select the appropriate method to survey Naegleria fowleri and Acanthamoeba spp. in water samples, four molecular biology techniques and one commercially available kit for real-time PCR were compared. The results indicated that the duplex real-time PCR was the most sensitive, and could be used to simultaneously detect two different free-living amoebas. Using the duplex real-time PCR approach, the two free-living amoebas were surveyed in three local streams in Daejeon, Republic of Korea. The concentrated free-living amoebas were inoculated onto non-nutrient agar plates which had been spread with heat-inactivated Escherichia coli and incubated for 5~7 days. After incubation, gDNA was extracted and used as the template for amplification by duplex real-time PCR. Acanthamoeba spp. and N. fowleri was detected from ten (83.3%) and two (16.6%) of the twelve samples, respectively. As these two free-living amoebas can be fatal, continuous surveillance is needed to track their distribution in the aquatic environment for the drinking water safety.