• 한국결정학회지
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• 제9권1호
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• pp.21-29
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• 1998

현재까지 알려진 마이크로 레이저 호스트용 물질 중에서 가장 우수한 물리적 특성을 갖고 잇는 LaSc3(BO3)4를 융액 인상법 조건하에서 단결정으로 육성시킬 수 있는 최적 성장조건을 규명하고자 하였다. 우선 LaSc3(B(3)4의 융융특성을 규명하기 위해 DTA에 의해 La(BO3)-Sc(BO3)계의 상평형도를 작성한 결과, 이 2성분계에서 LaSc3(BO3)4는 유일한 중간상(Intermediate phase)이었으며, 용융 전에 1495 ±2℃에서 Sc(BO3)와 융액으로 분리되는 비조화 분해반응(peritectic reaction)을 나타내었다 : LaSc3(BO3)4=Sc(BO3)+melt 히타 및 도가니의 상호관계와 단열 혹은 보온상태를 적절히 조절함으로써, 성장로의 열구조를 단결정 성장에 적합하게 하기 위해 열전대를 애프터히타 최상부로부터 융체 내부까지 상승 또는 하강시키면서 4개의 열 구조에 대해 온도분포와 온도구배를 측정 및 산출하였으며, 장단점을 비교하여 최적 성장조건을 확립하였다. LaSc3(BO3)4는 부조화 용융특성이 있으므로 화학양론적 조성에 La(BO3)를 다소 추가하여 특성 성분의 융액을 만들고, 인상속도를 0.7mm/hr이하, 회전속도는 7-10rpm의 환원조건 하에서 단결정을 성장시킬 수 있었다. 또한 결정성장때, Ir 및 백금 도가니를 사용할 수 있으나, 도가니의 수명은 가열/용융/냉각 주기가 최대 8-10회이다. 실험 결과 배플판 직경 등의 애프터 히타의 구조를 변화시킴으로써, 도가니 상부의 온도를 50-100℃ 증가시키는 것이 가능하였으며, 수직 및 수평적 온도구배는 배플판의 직경에 정비례하여 증감하였고, 특히 수평적 온도구배는 열구조에 의한 의존성이 크다는 것이 확인되었다.

• 대한화학회지
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• 제38권4호
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• pp.276-282
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• 1994

Citrate sol-gel법을 이용하여 perovskite형 복합산화물 LaBO$_3$(B = Mn, Fe, Co)을 공기 중 $850^{\circ}C$에서 24시간 동안 소성하여 제조하였다. X-선 회절분석(XRD)과 TPR결과에 의하면 이들 산화물의 결정구조와 산소화학양론은 LaMnO$_{3.16}$(a = 5.507, c = 13.329 $\AA$, hexagonal), LaFeO$_{3.17}$(a = 5.554, b = 5.555, c = 7.863 $\AA$, orthorhomibic), LaCoO$_{3.0}$(a = 5.436, c = 13.095 $\AA$, hexagonal)으로 수소 분위기(300torr)에서의 TPR결과에 의하면 이들 산화물은 2단계 환원반응으로 반응이 진행되며, 열적안정성은 LaMnO$_3$ > LaFeO$_3$ > LaCoO$_3$순으로 나타났고, 반응속도론적 결과 역시 LaCoO$_3$의 활성화에너지 값이 가장 낮음을 보였다.

• Journal of Animal Science and Technology
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• 제63권2호
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• pp.248-261
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• 2021

Attributable to their major function in pathogen recognition, the use of bovine leukocyte antigens (BoLA) as disease markers in immunological traits in cattle is well established. However, limited report exists on polymorphism of the BoLA gene in zebu cattle breeds by high resolution typing methods. Thus, we used a polymerase chain reaction sequence-based typing (PCR-SBT) method to sequence exon 2 of the BoLA class II DRB3 gene from 100 animals (Boran, n = 13; Sheko, n = 20; Fogera, n = 16; Horro, n = 19), Hanwoo cattle (n = 18) and Bangladesh Red Chittagong zebu (n = 14). Out of the 59 detected alleles, 43 were already deposited under the Immuno Polymorphism Database for major histocompatibility complex (IPD-MHC) while 16 were unique to this study. Assessment of the level of genetic variability at the population and sequence levels with genetic distance in the breeds considered in this study showed that Zebu breeds had a gene diversity score greater than 0.752, nucleotide diversity score greater than 0.152, and mean number of pairwise differences higher than 14, being very comparable to those investigated for other cattle breeds. Regarding neutrality tests analyzed, we investigated that all the breeds except Hanwoo had an excess number of alleles and could be expected from a recent population expansion or genetic hitchhiking. Howbeit, the observed heterozygosity was not significantly (p < 0.05) higher than the expected heterozygosity. The Hardy Weinberg equilibrium (HWE) analysis revealed non-significant excess of heterozygote animals, indicative of plausible over-dominant selection. The pairwise FST values suggested a low genetic variation among all the breeds (FST = 0.056; p < 0.05), besides the rooting from the evolutionary or domestication history of the cattle. No detached clade was observed in the evolutionary divergence study of the BoLA-DRB3 gene, inferred from the phylogenetic tree based on the maximum likelihood model. The investigation herein indicated the clear differences in BoLA-DRB3 gene variability between African and Asian cattle breeds.

• Current Photovoltaic Research
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• 제2권2호
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• pp.53-58
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• 2014

$Tb^{3+}$ - or $Ce^{3+}$-doped $LaBO_3$ phosphors were synthesized by a solid-state reaction process with different concentrations of activator ions. The XRD spectra showed the monoclinic $LaBO_3$ pattern with the main peak occurring at (014) plane, irrespective of the kind of activator ions. The crystallite size was determined by using the Scherrer formula, and the maximum was obtained with an activator concentration of 0.05 mol for both phosphors. The emission spectra of $LaBO_3$ phosphors doped with $Tb^{3+}$ ions under excitation at 269 nm exhibited three major emission bands at 488, 544, and 587 nm. The strongest emission was green at 544 nm owing to the $^5D_4-^7F_5$ transition at a $Tb^{3+}$ ion concentration of 0.05 mol. For the $Ce^{3+}$-doped $LaBO_3$ phosphors, one strong blue band centered at 469 nm and weak multipeaks were observed. These results suggest that the optimum green and blue emission can be realized by controlling the concentration and type of activator ions incorporated in the host crystal.

• 농업과학연구
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• 제25권1호
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• pp.79-88
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• 1998

본 연구는 축협중앙회 한우개량부에서 사육중인 한우의 혈액으로부터 genomic DNA를 추출하여 한우의 면역체계에 중요한 역할을 담당하고 있는 BoLA DRB3 exon2 유전자를 PCR기법을 이용하여 증폭하고 친자확인을 위한 이들 대립유전자들의 염기서열을 분석하여 한우의 효율적인 육종에 분자유전수준에서의 접목을 위한 기초자료를 얻고자 실시하였던바, 얻어진 결과를 요약하면 다음과 같다. 1 한우의 혈액에서 추출된 genomic DNA를 1.5% agarose gel에서 전기영동한 결과, 12.2kb이상의 단일밴드로 나타나, genomic DNA는 아주 잘 분리된 것으로 판단되었으며, 한편 genomic DNA로부터 PCR기법을 이용하여 BoLA DRB3 exon2 유전자를 증폭한 결과 284kb의 단편이 증폭 되었음을 확인하였다. 2. PCR 증폭산물을 pCR 2.1 vector를 사용하여 cloning 하고, 균주에 형질전환을 시켜 재조합 plasmid를 추출한 후, EcoR 1으로 처리한 결과 300bp 단편이 확인되어 증폭되어진 BoLA DRB3 exon2 유전자가 vector 내에 잘 삽입되었음을 확인하였다. 3. 부와 모의 BoLA DRB3 exon2 대립유전자의 염기서열을 분석한 결과 염기서열의 상동성은 부의 대립유전자간에는 82.0% 이었고, 모의 대립유전자간에는 90.1%이었다. 4. 친자를 확인하기 위해 부와 모 그리고 자손간의 가계에 대한 BoLA DRB3 exon2 대립유전자의 염기서열을 분석한 결과 Mendel 의 법칙에 따라 유전된다는 사실을 확인 할 수 있었다. 5. 이상의 결과를 종합하여보면 한우의 BoLA DRB3 exon2 유전자의 부와 모, 그리고 자손의 대립유전자에 대한 염기서열 수준에서의 친자확인이 가능하였으며, 이들 연구결과는 축우의 유전적 능력개량에 중요한 분자유전학적 기초 자료가 될 것으로 판단되었다.

• 농업과학연구
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• 제38권1호
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• pp.51-63
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• 2011

BoLA (bovine leukocyte antigens) have been known as gene complex related with bovine diseases and immunological traits. This study was conducted to find out the characteristics of BoLA-DRB3 gene related to mastitis and BL(bovine leukocyte) from 280 cattle [193 animals of Holstein cattle and 87 animals of Hanwoo]. As a result, five PCR-RFLP types (b, d, e, f and g) using HaeIII restriction enzyme, three BstYI restriction patterns (b, d and e) and eight RsaI restriction types(b, d, f, I, j, n, o and w) were identified. Moreover, we identified new d' type ($197{\rightarrow}175$/22), having one more cutting site by BstYI enzyme than d type allele and n' type ($180{\rightarrow}169$/11) having one more cutting site by RsaI enzyme than n allele was additionally identified. Next, we identified 53 SNPs in BoLA-DRB3 exon2 from 280 cattle. SNP frequency and heterozygosity of Holstein and Hanwoo were investigated in all the SNP genotype. These results might be based on research for identifying marker associated with bovine diseases.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.465-470
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• 2008

This study describes genetic variability in the BoLA-DRB3 gene in Iranian native cattle (Bos Indicus and Taurus) and relationships between these breeds. This is the first study of genetic polymorphism of the BoLA-DRB3 gene in Iranian native cattle. We examined exon 2 of the major histocompatibility complex (MHC) class II DRB3 gene from 203 individuals in four populations of Iranian native cattle (52 Sarabi, 52 Najdi, 49 Sistani, 50 Golpayegani cattle) using the hemi-nested PCR-RFLP method. We identified the 36 previously reported alleles and one novel pattern (*eac). Analysis of the frequencies of the various BoLA-DRB3.2 alleles in each breed indicated that DRB3.2*52 in Sarabi cattle (23%), DRB3.2 *14 and *24 alleles in Najdi cattle (13%), DRB3.2 *8 allele in Sistani cattle (22%) and DRB3.2*16 allele in Golpayegani cattle (14%), were the most frequent alleles. Allelic frequencies ranged from 1 to 23% among the 36 alleles and there were some alleles that were found only in Iranian cattle. Effective number of alleles in the four breeds was estimated to be 7.86, 11.68, 7.08 and 3.37 in Sarabi, Najdi, Sistani and Golpayegani, respectively. Observed heterozygosities were the highest in Sarabi (94%) and Najdi (94%). A population tree based on the frequency of BoLA-DRB3.2 alleles in each breed suggested that Najdi, Sarabi and Golpayegani cattle clustered together and Najdi and Sarabi were the closest breeds. Sistani cattle differed more from these three breeds. These new data suggest that allele frequencies differ between Iranian cattle breeds.

• Bulletin of the Korean Chemical Society
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• 제9권5호
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• pp.283-288
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• 1988

The titled properties on reduction of the perovskite $LaBO_3$ (B = Fe, Co, Ni) have been investigated by means of temperature-programmed reduction, isothermal reduction and X-ray diffraction methods. Nominal composition of $LaFeO_{3.18},\;LaCoO_{3.00}\;and\;LaNiO_{2.92}$ are determined. Reduction reaction of these mixed oxides differed according to B-site transition metal and thermal stability on reduction decreased as following order: $LaFeO_{3.18}$ > $LaCoO_{3.00}$ > $LaNiO_{2.92}$. From the results of isothermal reaction, kinetics on reduction of the perovskite has been discussed in detail.

• 한국세라믹학회지
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• 제53권6호
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• pp.712-718
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• 2016

In this study, we investigate the effect of the$Li_3BO_3$ additive on the densification and ionic conductivity of garnet-type $Li_7La_3Zr_2O_{12}$ solid electrolytes for all-solid-state lithium batteries. We analyze their densification behavior with the addition of $Li_3BO_3$ in the range of 2-10 wt.% by dilatometer measurements and isothermal sintering. Dilatometry analysis reveals that the sintering of $Li_7La_3Zr_2O_{12}-Li_3BO_3$ composites is characterized by two stages, resulting in two peaks, which show a significant dependence on the $Li_3BO_3$ additive content, in the shrinkage rate curves. Sintered density and total ion conductivity of the system increases with increasing $Li_3BO_3$ content. After sintering at $1100^{\circ}C$ for 8 h, the $Li_7La_3Zr_2O_{12}-8$ wt.% $Li_3BO_3$ composite shows a total ionic conductivity of $1.61{\times}10^{-5}Scm^{-1}$, while that of the pure $Li_7La_3Zr_2O_{12}$ is only $5.98{\times}10^{-6}Scm^{-1}$.

• 대한수의학회지
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• 제35권2호
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• pp.307-315
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• 1995

The characterization of the MHC of domestic animals may constitute a first step towards increasing the efficiency of food production through improved disease resistance. In order to study the role of the MHC in regulating immune response it is first necessary to identify the different MHC alleles. In this research we try to investigate the possible associations between BoLA of Korean native cattles and infectious cattle disease. For this purpose we used one approach, serology. The results were summarized as follows : 1. Korean native cattle's lymphocyte reacted with alloantisera which recognized seven official BoLA allele. Korean native cattle's lymphocytes were reacted same as European breeds(especially with 673/3(W20)). 2. Korean native cattle's lymphocytes reacted with alloantisera 773/2, 673/3, 638/3, 773/3, 602/2, 639/2 and 639/3 at high reaction frequency. But alloantisera 642/1 was not expressed on Korean native cattle. If this allele, recognized by alloantisera(642/1), officially certificate In BoLA workshop it will be characterization factor of Korean native cattle. 3. According to cellular similarity index, we can presume on genetic relativity which has no family relationship.