• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.217-220
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• 1995

By substituting Cd$\^$2+/ into both A-site and B-site in PNN-PZ-PT ternary perovskite material, it is possible to determine the effects of the substitution site of Cd$\^$2+/ on sintering behavior. Sintering was performed in the temperature range from 1000$^{\circ}C$ to 1300$^{\circ}C$. The substitution site of Cd$\^$2+/ is identified by XPS spectra. Although Cd$\^$2+/ is substituted into both A-site and B-site in PNN-PZ-PT, Cd$\^$2+/ prefers A-site to B-site. The density is influenced by substitution site of Cd$\^$2+/. If Cd$\^$2+/ replaces Pv$\^$2+/, weight gain is observed during sinterig process. On the contrary, if Cd$\^$2+/ replaces Ni$\^$2+/, weight loss is promoted during sintering. From these weight changes, it is believed that Cd$\^$2+/ changes the bonding strength between B-site cation and oxygen of octahedron in perovskite structure. The changes of lattice parameters as a function of Cd$\^$2+/ content were consistent with those of the bonding strength. The densities of A-site-doped compositions were higher than those of B-site-doped composition.

• Journal of the Korean Ceramic Society
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• v.37 no.5
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• pp.491-496
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• 2000

Single phae Pb(Mg1/3Nb2/3)O3-based solid solutions, the Mg2+ of which are replaced by 20mol% of Ni2+, Zn2+, Cd2+, and the Pb2+ of which are replaced by 0∼20 mol% of La3+, were synthesized and their ordering structures of B-site cations were investigated by XRD and TEM. The B'-site cations (Mg2+, Ni2+, Zn2+, Cd2+) are disordered while these B'-site cations and the B"-site cations (Nb5+) are nonstoichiometrically 1:1 ordered within the ordered nano-domains dispersed in the Nb5+-rich disordered matrix. The charge imbalance between the B'-rich ordered nano-domains and the B"-rich disordered matrix are compensated by the doping of electron donor such as La3+, which enhances the degree of nonstoichiometric 1:1 ordering. For a given La3+ content, the degree of nonstoichiometric 1:1 ordering increases as the average ionic size difference between the B'-and B"-site cations increases, Ni2+

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.1
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• pp.16-23
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• 1996

Spatial distribution characteristics, volume backscattering strength and species composition of midwater trawling catch was analyzed biological and acoustical characteristics of anchovy shoal, using a high resolution echo - sounder at the south region of East sea of Korea. 1) In the survey site A of Lat.35$^{\circ}$55'N, Long.129$^{\circ}$45'E, the anchovy shoal of small to middle size with the horizontal range of 10~25m and large size with the horizontal range of 40~50m were distributed together. However in the survey site B of Lat.35$^{\circ}$38'N, Long.129$^{\circ}$40'E, the anchovy shoal was observed to be mainly small size which about 78% of the detected shoal. Another was that the anchovy shoal with the vertical range of 2~8m occupied about 68.6% in the survey site A and that of 6~12m occupied about 42.5% in the survey site B. The mainly the site A and B were found to be 10~50m super (2), 64.5% and 20~80m super (2), 66%, respectively. 2) The volume backscattering strength in the site A and B were observed to be -44.0~ -28.0dB, respectively. In the site A, the backscattering strength of -40.0~ -30.0dB was analyzed about 41.4%. 3) Most of total anchovy shoal was concentrated in the water layer of 50~100m in depth with 15.3~18.5$^{\circ}C$, 34.0~34.3$\textperthousand$ in the survey site A and 14.2~16.4$^{\circ}C$, 34.1~34.2$\textperthousand$ in the survey site B. 4) Mean total length(TL) and body weight(BW) of anchovy in the survey site A were 9.9cm and 4.4g respectively, with TL-BW relationship of BW=0.0007T$L^3.65$super (3.85). In site B, mean total length(TL) and body weight(BW) were 11.2cm and 8.7g, with TL-BW relationship of BW=0.0023T$L^3.36$.

• The Korean Journal of Ceramics
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• v.2 no.2
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• pp.76-82
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• 1996

PLZT ceramics having two nominal compositions, $Pb_{1-3x/2}La_xV_{x/2}(Zr_{03}Ti_{03})O_3$ and $Pb_{1-x}La_x(Zr_{0.2}Ti_{0.5})_{1-x/4}V_{x/4}O_3$ (V: vacancy) with x=0.00~0.30, were prepared. The physical, structural, and dielectric properties were investigated by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, and measurements of bulk density and dielectric constant. The two series with A-stie and B-site vacancies showed different physical, structural, dielectric properties, and, specially, Curie temperature. In comparison to PLZT with B-site vacancies, PLZT with A-site vacancies showed high Curie temperatures and low maxima of dielectric constant. Consequently, it is evident that the properties of PLZT ceramics depend on the vacancy formula adopted as a batch composition in preparation.

• Korean Journal of Materials Research
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• v.11 no.1
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• pp.3-7
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• 2001

$M\"{o}ssbauer$ spectra of the $Ni_{1+x}Ti_xFe_{2-2x}O_4$ systems ($0{\leqq}x{\leqq}0.7$), which appear as single phase spinel structure, were examined at RT. The $M\"{o}ssbauer$ spectra reveal two sextet for $0{\leqq}x{\leqq}0.3$, two sextet and a doublet for $0.4{\leqq}x{\leqq}0.6$, and a doublet for x=0.7 As x increases, the area ratio of B-site and A-site($A_B/A_A$) of the sextet decreases, and the area ratio of the doublet and the total areas($A_{doublet}/A_{tot.}$) increases. The isomer shift(I.S.) of A-site slightly increases and magnetic hyperfine fields($H_{hf}$) of two sites decrease as the increasing x. From these results, we have obtained the cation distributions of the samples and concluded that the increasing x leads to the decrease of covalency of $Fe^{3+}-O^{2-}$ bond in A-sites and A-B superexchange interactions.eractions.

• The Korean Journal of Ecology
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• v.10 no.1
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• pp.23-31
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• 1987

This study was carried out to investigate by the MGP analysis the composition of oribatid mite in coniferous and broad-leaved forests, Kwang Yng experiment plantation, Chola Nam Do Province, southern part of Korea. In these study area, 157 species of oribatid mites (Acari: Cryptogimata) were identified. Among them 6 species such as; Brachychochthonius jugatus JACOT, B hungaricus BALOGH, Eremulus translamealtus BALOGH et. MAHUNKA, Brachioppiella ctenifera GOLOSOVA, Striatoppia opuntiseta BALOGH et. MAHUNKA, Suctobelba perdentata baculifer BALOGH et. MAHUNKA have not been described in Korea. Species compositions were as follows; Among them 69 species were found in all the six sampling sites, 33 species scattered sporadically in all the area, 12 species found in coniferous forest, 10 species in broad-leaved forest only, and 33 species sampled at one site. According to the MGP analysis I, site B-1, B-2, and B-3 were found to be "Type G" and site C-1, C-2, and C-3 were "Type MG". According to the MGP analysis II, site B were found to be all "Type G". But site C-1 was "Type MG", C-2 was "Type M" and C-3 was "Type G" suggesting that "Group M" increased in the site C.e G" suggesting that "Group M" increased in the site C. in the site C.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.140-145
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• 2005

Streptomyces natalensis ATCC27448 produces natamycin, a commercially important macrolide antifungal antibiotic. For molecular genetic study of S. natalensis, we have developed a system for introducing DNA into S. natalensis via conjugal transfer from Escherichia coli. An effective transformation procedure for S. natalensis was established based on transconjugation from E, coli ET12567/pUZ8002 using a ${\Phi}C31$-derived integration vector, pSET152, containing oriT and attP fragments. The high frequency was obtained on MS medium containing 10 mM $MgCl_2$ using $6.25\times10^8$ of E.coli donor cells without heat treatment of spores. In addition, southern blot analysis of exconjugants and the sequence of plasmids containing DNA flanking the insertion sites from the chromosome revealed that S. natalensis contains a single ${\Phi}C31$ attB site and at least a secondary or pseudo attB site. Similar to the case of various Streptomyces species, a single ${\Phi}C31$ attB site of S. natalensis is present within an ORF encoding a pirin-homolog, but a pseudo-attB site is present within a distinct site (GenBank accession no. $YP\_117731$) and also its sequence deviates from the consensus sequences of attB sequence.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.84-88
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• 2016

To understand the effects of habitat characteristics on the genetic diversity of Persicaria thunbergii, three sites of different environmental conditions in a water system were surveyed. Site A was the closest to the source of the water system, and there was a dam between sites A and B. Site C is located on the lowest downstream in the water system. Vegetation survey of four quadrats at each site was performed, and soil samples were collected for physicochemical analysis. Random amplification of polymorphic DNA (RAPD) analysis of ten P. thunbergii individuals at each site was conducted to calculate population genetic diversity and genetic distance among populations. Soil was sterile sand at site A, whereas loamy soil at sites B and C. A pure stand of P. thunbergii appeared at site A, while other species occurred together (such as Humulus japonicus and Phragmites australis) at sites B (Shannon-Wiener index; $H_B=0.309$) and C ($H_C=0.299$). Similar to the species diversity, genetic diversity (Nei's gene diversity; h) within population of site A ($h_A=0.2381$) was relatively lower than sites B ($h_B=0.2761$) and C ($h_C=0.2618$). However, site C was separated from sites A and B in genetic distance rather than the geographical distance (Nei's genetic distance; A~B, 0.0338; B~C, 0.0685; A~C, 0.0833).

• Economic and Environmental Geology
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• v.47 no.1
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• pp.71-85
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• 2014

To study biogeochemical characteristics and origin organic matter, sediment samples were taken from Site of 1249C and Stie 1251B of ODP Leg 204. Data of Rock-Eval, isotope, and element analysis generally indicate dominance of marine organic matter in sediments deposited under marine sedimentary environment. Only Rock-Eval data are somewhat different from those of others owing to under-maturation of organic matter. Samples of Site 1249C show high content of gas hydrate, whereas Site 1251B low content of gas hydrate in some intervals of the core. This result may be accounted to different location of two cores and presence of transportation passage (Horizon A, BSR 2) of thermogenic gas in the core, 1249 C. However, Site 1251B Located in the basin of low accumulation of gas hydrate is presumed to be limited in the gas hydrate production. Because not only transportation passage is limited to move thermogenic gas from the core, but also gas supply was not enough. Therefore, the biogenic gas that resulted from diagenesis of there sediment is superior.

• IE interfaces
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• v.17 no.1
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• pp.33-45
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• 2004

In the web environment for general information seeking and business-to-customer and business-to-business electronic commerce, users are customers. Understanding their expectations and how they feel about the web sites they use is becoming a very serious concern. While the success of a company or an organization is dependent on many factors, its web site plays a central role. This paper described the use of WebQual2.0 to evaluate the various web sites of B2B and B2C. WebQual2.0 has been extended and refined to encompass an interaction-quality literature. Furthermore, this paper described the use of Kano model to evaluate the various web sites which classified by internet business types. The result showed that the inherent characteristics of B2B and B2C web site should be considered in initial site construction. Further, customers in a web domain do not regard all quality factors as equally important and the rankings of important quality factors differ from one web domain to another. This study was focused on the identifying the weights of web quality factors according to the each web site of the internet business types.