• 한국세라믹학회지
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• 제39권6호
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• pp.598-603
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• 2002

(M $g_{0.93}$C $a_{0.07}$)Ti $O_3$마이크로파 유전체 세라믹스에 alumine borosilicate계 유리를 5~30wt% 첨가하여 저온소결 특성과 마이크로파 유전 특성을 조사하였다. (M $g_{0.93}$C $a_{0.07}$)Ti $O_3$에 alumine borosilicate계 유리를 첨가함으로서 소결온도를 135$0^{\circ}C$에서 95$0^{\circ}C$로 낮추었으며, 유리의 첨가량이 증가함에 따라 소결밀도의 증가 및 입성장이 뚜렷이 나타났고 20~30wt%의 유리가 첨가된 영역에서는 95%의 상대밀도를 갖는 소결체를 얻을 수 있었다. (M $g_{0.93}$C $a_{0.07}$)Ti $O_3$에 20wt%의 alumino boiosilicate계 유리를 첨가함으로서 95$0^{\circ}C$에서 유전율($\varepsilon$$_{r}$)은 15~16, 품질계수(Q$\times$f)는 8000이었으며, 이때 공진주파수의 온도 계수($ au$$_{cf}$ )는 -45 ppm/$^{\circ}C$을 나타내었다.

• 한국산림과학회지
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• 제98권4호
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• pp.496-503
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• 2009

간척지는 높은 토양 염도와 지하수위로 인해 수목의 생육에 적합하지 않은 환경으로 알려져있다. 그러나 과거 농경지로 사용되던 간척지가 최근 들어 산업단지, 주거단지, 또는 공원으로 전환되면서 이 지역에 수목 식재의 필요성이 높아지고 있다. 본 연구는 농경지에서 다른 용도로 전환되는 지역 중 하나인 충남 서산 간척지에 도입할 수 있는 내염성 수종을 선택하기 위하여 수행되었다. 서로 다른 복토 재료(준설토, 준설토+산토)와 복토 높이(1.5 m, 2.0 m)를 이용하여 시험 포지를 조성한 후 8개 수종-소나무(Pinus densiflora), 곰솔(Pinus thunbergii), 메타세콰이어(Metasequoia glyptostroboides), 이팝나무(Chionanthus retusus), 산딸나무(Cornus kousa), 산벚나무(Prunus sargentii), 상수리나무(Quercus acutissima), 느티나무(Zelkova serrata)-의 묘목을 대상으로 2006년 4월에서 2008년 11월까지 매년 고사율과 수목 생장을 조사하였다. 3년간 묘목의 생존율은 수종 간 유의한 차이를 보였다(F=9.632, P<0.001). 산딸나무, 상수리나무, 산벚나무는 50% 이상의 상대적으로 높은 고사율을 보였으며, 해송, 메타세콰이어, 느티나무가 각각 3년 평균 고사율 6.4%, 2.3%, 24.7%로 상대적으로 생존율이 높았다. 묘목의 수고 생장 역시 수종간 유의한 차이를 보였다(F=4.749, P=0.002). 메타세콰이어와 느티나무가 절대생장과 식재 당시 대비 상대 생장 모두를 고려했을 때 상대적으로 높은 수고 생장을 보였다. 대부분의 수종들이 이식 다음해에는 낮은 생장을 보였으며, 이식 2년 후부터 생장이 회복되었다. 수종에 관계없이 복토 높이가 높을수록, 준설토보다는 산림토양을 복토하였을 때에 수목의 생존율과 생장이 높게 나타났다. 해송, 메타세콰이어, 느티나무가 타 수종에 비해 높은 생존율과 생장을 보여 이 지역에 상대적으로 적합한 수종으로 나타났으며, 이팝나무, 산딸나무와 산벚나무는 이 지역에서 적응력이 떨어지는 것으로 판단되었다.

• 생태와환경
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• 제39권4호통권118호
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• pp.450-461
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• 2006

본 연구에서는 pH 5.5에서 연안퇴적물내 납과 카드뮴의 흡착 동력학을 실험실규모의 회분식 반응기를 이용하여 조사하였다. 4종류의 모델: 단일영역 물질전달모델 (one-site mass transfer model, OSMTM), 겉보기 1차속도모델 (pseudo-first-order kinetic model, PFOKM), 겉보기 2차속도모델 (pseudo-second-order kinetic model, PSOKM)과 두영역 1차속도모델 (two compartment first-order kinetic model, TCFOKM)을 사용하여 흡착속도를 분석하였다. 관련된 모델매개변수의 수에서 기대되듯이 변수가 3개인 TCFOKM이 변수가 2개인 OSMTM, PFOKM, PSOKM 보다 흡착속도를 더 잘 표현할 수 있었다. 납과 카드뮴의 대부분의 흡착은 초기 3시간 이내에 빠르게 완료되었으며, 이후 기간 동안은 느린 흡착이 이루어졌다. 모든 모델에서 겉보기 흡착평형농도($q_{e,s}$)는 퇴적물의 양이온 교환능 (CEC)과 표면적이 증가함에 따라 증가하는 것으로 예측되었으며, 이는 초기 중금속 투여 농도와 중금속 및 퇴적물의 형태와 무관하였다. OSMTM에서의 흡착속도 상수 ($k_s,\;hr^{-1}$)는 퇴적물의 CEC와 표면적이 증가함에 따라 증가하였다. PFOKM의 겉보기 1차흡착속도상수 ($k_{p1,s},\;hr^{-1}$)는 퇴적물의 특성과 관련이 없었다. PSOM 분석결과 겉보기 2차흡착속도상수 ($k_{p2,s},\;g\;mmol^{-1}\;hr^{-1}$)와 초기흡착속도 ($v_{o,s},\;mg\;g^{-1}\;hr^{-1}$)는 퇴적물의 특성과 연관되지 않았다. TCFOKM의 빠른 흡착영역의 분율($f_{1,s}$)은 수용액상의 초기농도와는 무관하게 퇴적물의 CEC와 표면적이 증가함에 따라 증가하였다. 빠른 부분에서의 흡착속도 상수 ($k_{1,s}=10^{0.1}-10^{1.0}\;hr^{-1}$)는 느린 부분에서의 흡착속도 상수 ($k_{2,s}=10^{-2}-10^{-4}\;hr^{-1}$)보다 훨씬 더 큰 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.755-765
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• 2013

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD), Landrace (CL) and Yorkshire (CY) swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.

• 한국산림과학회지
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• 제111권2호
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• pp.234-241
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• 2022

본 연구는 고령토 광산 식생 복원지와 인접 소나무 임분을 대상으로 토양양분 저장량을 비교하고 복원지 식생의 잎 양분 농도와 토양 특성과의 관계를 조사하였다. 경상남도 산청군에 위치한 고령토 광산은 복원 식생으로 목본은 상수리나무와 잣나무, 초본은 큰김의털과 비수리가 식재 또는 파종되었다. 한편, 일부 식생 복원지는 인접 산림으로부터 유입된 물오리나무, 아까시나무, 싸리류 등이 침입 식생으로 분포하였다. 토양 0~10 cm 깊이의 탄소 및 질소 저장량은 소나무 임분이 식생 복원지에 비해 유의적으로 높았으나(P < 0.05), 인, 포타슘, 마그네슘 저장량은 유의적인 차이가 없었으며, 칼슘 저장량은 식생 복원지가 높게 나타났다. 식생 복원지에 조성된 비수리 잎 내 질소 농도는 20.28 mg N g^-1로 큰김의털 5.67 mg N g^-1에 비해 약 3배 정도 높았으나, 포타슘 농도는 비수리가 9.07 mg K g^-1로 큰김의털 18.8 mg K g^-1에 비해 약 2배정도 낮았다. 침입 식생인 물오리나무, 싸리류, 아까시나무는 잣나무나 상수리나무 같은 식재 수종에 비해 잎 내 질소 농도가 2~4배 정도 높게 나타났다. 본 연구에 따르면 고령토 광산 식생 복원지의 열악한 토양 특성을 고려할 때 복원 수종으로 질소고정식물을 식재하거나 파종하고 토양 비옥도를 향상할 수 있는 산림 사업이 필요한 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.267-271
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• 2012

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol ($1{\alpha}$-OH $D_3$) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of $1{\alpha}$-OH $D_3$ (0, 5, and 10 ${\mu}g$/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin $D_3$. As a result of this study, the addition of $1{\alpha}$-OH $D_3$ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary $1{\alpha}$-OH $D_3$ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, $1{\alpha}$-OH $D_3$ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the $1{\alpha}$-OH $D_3$ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1197-1205
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• 2006

This experiment was conducted to compare the effects of feeding DL-2-hydroxy-4-(methylthio)butanoic acid (HMTBA) and DL-methionine (DLM) supplemented corn-soybean-cottonseed meal diets on growth performance, carcass composition, and muscle color of broilers. The trial was designed as a $2{\times}3{\times}2$ factorial experiment, including two methionine (Met) sources (HMTBA and DLM), three equimolar graded levels of Met supplementation (i.e., 0.08, 0.16, and 0.24% in the starter diet and 0.07, 0.14, and 0.21% in the grower and finisher diets, respectively), and two sexes (male and female). Additionally, one basal diet for each sex was formulated to be limiting in Met to test the dosage response of increasing supplemental Met levels. Four hundred and twenty 10-d-old broilers were randomly allotted to 14 treatments (seven each for males and females), with five replicate pens per treatment and six chicks per pen. There was no difference (p>0.05) between the two Met sources in growth performance and muscle deposition of broilers throughout the whole experimental period (d 10 to 49). With the increasing Met supplementation levels, average daily gain was increased (quadratic; p<0.01) during the starter, grower, and overall phases, average daily feed intake was increased (quadratic; p<0.01) during the starter phase, and feed:gain ratio was decreased (quadratic; p<0.05) during the grower and overall phases. At the end of finisher phase, Met supplementation increased breast muscle content (quadratic; p<0.01) and thigh muscle content (linear; p<0.05), and decreased abdominal fat content (quadratic; p<0.02). Compared to the broiler fed DLM, broilers fed HMTBA had superior breast and thigh muscle coloration (p<0.01). Male broilers had higher weight gain and feed intake and better feed conversion than female broilers (p<0.01). The fat content of thigh muscle in female broilers was higher than that of male broilers (p<0.03). The best fit comparison of HMTBA vs. DLM was determined by Schwarz Bayesian Criteria index, which indicated that the average relative bioefficacy of HMTBA vs. DLM was 120% with 95% confidence limit 67 to 172%. These results indicated that Met supplementation improved growth performance and carcass quality of broilers fed corn-soybean-cottonseed meal diets irrespective of Met sources. Compared to DLM, HMTBA has the same molar bioefficacy on improving the growth performance and carcass quality of broilers; however, HMTBA fed birds had superior meat color to DLM fed birds.

• Animal Bioscience
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• 제34권2호
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• pp.276-284
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• 2021

Objective: The objective of this study was to determine whether a dietary vitamin E (VE) supplement could alleviate any detrimental effects of aged corn on lipid metabolism and antioxidant status in laying hens. Methods: The experiment consisted of a 2×3 factorial design with two corn types (normal corn and aged corn (stored for 4 yr) and three concentrations of VE (0, 20, and 100 IU/kg). A total of 216 Lohmann laying hens (50 wk of age) were randomly allocated into six treatment diets for 12 wk. Each treatment had 6 replicates of 6 hens per replicate. Results: The results show that aged corn significantly decreased the content of low-density lipoprotein cholesterol (p<0.05), and reduced chemokine-like receptor 1 (CMKLR1) mRNA expression (p<0.05) in the liver compared to controls. Diet with VE did not alter the content of crude fat and cholesterol (p>0.05), or acetyl-CoA carboxylase, lipoprotein lipase, fatty acid synthase or CMKLR1 mRNA expression (p>0.05) in the liver among treatment groups. Aged corn significantly increased the content of malondialdehyde (MDA) (p<0.05) and decreased superoxide dismutase (SOD) activity (p<0.05) in the liver. The VE increased the content of MDA (p<0.05) but decreased glutathione peroxidase (GSH-Px) activity in serum (p<0.01) and in the ovaries (p<0.05). Adding VE at 20 and 100 IU/kg significantly increased GSH-Px activity (p<0.05) in liver and in serum (p<0.01), 100 IU/kg VE significantly increased SOD activity (p<0.05) in serum. Aged corn had no significant effects on GSH-Px mRNA or SOD mRNA expression (p<0.01) in the liver and ovaries. Addition of 100 IU/kg VE could significantly increase SOD mRNA expression (p<0.01) in the liver and ovary. Conclusion: Aged corn affected lipid metabolism and decreased the antioxidant function of laying hens. Dietary VE supplementation was unable to counteract the negative effects of aged corn on lipid metabolism. However, addition of 100 IU/kg VE prevented aged corninduced lipid peroxidation in the organs of laying hens.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.928-935
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• 2008

The myostatin gene of seven important meat (Beltex (Australia), Beltex$\times$Huyang (F1), Meat and Multi-Prolific Chinese Merino Fine Wool, Meat Chinese Merino Fine Wool and Dorper (South Africa)) and non-meat (Huyang and Kazak) sheep breeds was analyzed to study the genetic basis of muscular hypertrophy (double muscling) phenotype in sheep. SNPs, four in regulatory regions and several in the introns in the myostatin gene, were identified, and the former four SNPs were used for further studies. Twelve haplotypes were predicted by PHASE program, of which four main haplotypes (1, 3, 7, 9) were present in 90% of the 364 sheep in the study. Haplotypes 1-4 were mainly present in meat breeds while haplotypes 7 and 9 dominated the non-meat breeds. The association between haplotypes and average daily gain (ADG) was analyzed among 116 sheep with production data, Haplo2 (CGAA) and Haplo8 (TGAA) were identified to have significant (p<0.05) effect on ADG by the model (JMP5.1 software) taking into account the effects of breed, family background, haplotype, birth weight and sex. ADG of these haplotype groups also correlated well (r = 0.82) with hypertrophic phenotype scores. In conclusion, the mutations -956 (T$\rightarrow$C), -41 (C$\rightarrow$A) and 6223 (G$\rightarrow$A) involved in Haplo2 and 8 may be associated with the double-muscling trait by influencing myostatin function and be suitable markers in selecting meat sheep.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.285-295
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• 1999

Electroluminescent(EL) devices based on organic materials have been of great interest due to their possible applications for large-area flat-panel displays. They are attractive because of their capability of multi-color emission, and low operation voltage. An approach to realize such device characteristics is to use active layers of lanthanide complexes with their inherent extremely sharp emission bands in stead of commonly known organic dyes. In general, organic molecular compounds show emission due to their $\pi$-$\pi*$ transitions resulting in luminescence bandwidths of about 80 to 100nm. Spin statistic estimations lead to an internal quantum efficiency of dye-based EL devices limited to 25%. On the contrary, the fluorescence of lanthanide complexes is based on an intramolecular energy transfer from the triplet of the organic ligand to the 4f energy states of the ion. Therefore, theoretical internal quantum efficiency is principally not limited. In this study, Powders of TPD, $Eu(TTA)_3(phen) and AlQ_3$ in a boat were subsequently heated to their sublimation temperatures to obtain the growth rates of 0.2~0.3nm/s. Organic electrolumnescent devices(OELD) with a structure of $glass substrate/ITO/Eu(TTA)_3(phen)/AI, glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AI and glass substrate/ITO/TPD/Eu(TTA)_3(phen)/AIQ_3AI$ structures were fabricated by vacuum evaporation method, where aromatic diamine(TPD) was used as a hole transporting material, $Eu(TTA)_3(phen)$ as an emitting material, and Tris(8-hydroxyquinoline)Aluminum$(AlQ_3)$ as an electron transporting layer. Electroluminescent(EL) and current density-voltage(J-V) characteristics of these OELDs with various thickness of $Eu(TTA)_3(phen)$ layer were investigated. The triple-layer structure devices show the red EL spectrum at the wavelength of 613nm, which is almost the same as the photoluminescent(PL) spectrum of $Eu(TTA)_3(phen)$.It was found from the J-V characteristics of these devices that the current density is not dependent on the applied field, but on the electric field.