• The Korean Journal of Ecology
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• 제16권4호
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• pp.477-487
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• 1993

온대낙엽수림의 수 종 목본식물에서 생육초기의 기온과 개엽시기와 관계를 규명하기 위하여 남한산성과 지역에서 1991, 1992 및 1993년 대관령 지역에서 1992년, 3월부터 5월까지 겨울눈의 파열 시기, 개엽이 완료된 시기, 개화 및 낙화의 시기를 관찰 조사하고 이것을 기상자료와 관련시켜 분석하였다. 남한산성 지역에서 개엽이 이른 종은 신갈나무, 진달래, 개벚나무, 노린재나무 등으로 4월 초순이었으며, 늦은 종은 굴참나무, 떡갈나무, 다릅나무 등으로 4월 하순이었다. 그리고 가장 빠른종인 진달래 (4월 8일)와 가장 늦은 종인 굴참나무, 다릅나무 및 떡갈나무 (5월 4일)의 차이는 27일 이었다. 두 지여간 동일 수종의 개엽시기를 비교하면, 남한산성의 것은 대관령 지역의 것보다 8~24일 빨랐다. 한편, 두 지역간 개화시기의 차이는 0~22일로 개엽시기의것보다 적었다. 겨울눈의 파열시기는 일적사온량지수(YDI)와 관계가 있지만 개엽이 완료되는 시기나 개화시기를 예측하는 데는 YDI보다 Nuttonoson의 온량지수(Tn)가 더욱 유효한 것으로 나타났다.

• Parasites, Hosts and Diseases
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• 제56권5호
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• pp.521-525
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• 2018

Rodents are well-known reservoirs and vectors of many emerging and re-emerging infectious diseases, but little is known about their role in zoonotic disease transmission in Bhutan. In this study, a cross-sectional investigation of zoonotic disease pathogens in rodents was performed in Chukha district, Bhutan, where a high incidence of scrub typhus and cases of acute undifferentiated febrile illness had been reported in people during the preceding 4-6 months. Twelve rodents were trapped alive using wire-mesh traps. Following euthanasia, liver and kidney tissues were removed and tested using PCR for Orientia tsutsugamushi and other bacterial and rickettsial pathogens causing bartonellosis, borreliosis, human monocytic ehrlichiosis, human granulocytic anaplasmosis, leptospirosis, and rickettsiosis. A phylogenetic analysis was performed on all rodent species captured and pathogens detected. Four out of the 12 rodents (33.3%) tested positive by PCR for zoonotic pathogens. Anaplasma phagocytophilum, Bartonella grahamii, and B. queenslandensis were identified for the first time in Bhutan. Leptospira interrogans was also detected for the first time from rodents in Bhutan. The findings demonstrate the presence of these zoonotic pathogens in rodents in Bhutan, which may pose a risk of disease transmission to humans.

• Journal of the Korean Wood Science and Technology
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• 제18권3호
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• pp.53-68
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• 1990

This research has been executed for maximization of lumber yield and more efficient use of small diameter logs. Sample logs from thinnings carne from densed artificial stands at the Kwangnung Experimental Forests situated in the central region of Korean peninsula. Species of sample logs were obtained to execute sawing and strength test for larch, and lumber strength test in full size for pitch pine and Korean pine. A survey on sawmills consuming domestic logs was carried out to know sawmill production, costs and utilization structure of lumber as a guide to business analysis. Results showed that sawing pattern from small logs less than 15cm in diameter was necessary to cut 9cm by 9cm square per one log in order to obtain high lumber recovery and provide for wide market needs. The total lumber yield of squares plus side boards was 56 percent to 58 percent from small logs and the yield for log sweep in 30 percent decreased by 24.5 percent in sawing production, compared to yield for straight logs. In sawing efficiency, production of lumber by twin band saw could be improved 238 percent higher than lumber of the same species produced by conventional sawmilling methods, and sawing accuracy with twin band saw was much higher at the lumber production than band saw. Lumber from the small larch logs has shown 70 knots per $m^2$ on its faces and also lumber showed lots of face checkings by air drying on the yard, compared to other species. MOR in bending of lumber in full size from small logs of larch was found ranging from 380kg/$cm^2$ to 460kg/$cm^2$, resulting in 40 percent less than the strength from clear small specimens. In lumber containing knots, cross grain, etc, longitudinal stress wave speed was delayed about 48 percent by defects in lumber from both larch and pitch pine logs. The surveyed sample sawmills consumed the domestic logs at the rate of 54 percent to 84 percent in the total timber consumption, showing high consumption at mills located in the mountains.

• 한국잠사곤충학회지
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• 제16권1호
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• pp.57-65
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• 1974

5령기에 있어서 사료중 단백질 함량이 유충의 증체량, 사료방률에 미치는 영향과 간접적으로 유충의 소화액 Amylase 활성에 미치는 영향을 알기 위하여 상엽분말을 넣은 인공사료를 사용해서 단백질 급원으로 Soybean meal함량에 따라 6종의 사료를 만들어 누에를 사육한 결과 다음과 같은 결과를 얻었다. 1. 사료중 단백질 함량의 증가에 비례하여 유충의 증체량도 비례하여 많았다. 2. 사료중 단백질 함량의 증가에 비례하여 전견중 및 견층중도 비례하여 무겁다. 3. 사료중 단백질 함량의 증가에 비례하여 유충의 소화양 및 소화율도 비례하여 높았다. 4. 사료중 단백질 함량의 증가에 비례하여 유충의 사료방률도 비례하여 높았다. 5. 그러나 사료중 단백질 함량의 증가와 유충의 소화액 Amylase 활성 간에는 일정한 상관관계가 없었다.

• Journal of the Korean Wood Science and Technology
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• 제46권6호
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• pp.726-734
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• 2018

In this study, for using effectively domestic (temperate) small and medium diameter logs as a wooden floorboard, cross-laminated wood panels were manufactured using domestic larch and tulip woods as a base material for teak and merbau wood flooring, and static bending strength performances were measured to investigate the applicability as the base materials of wooden flooring in place of plywood. Static bending MOE was much influenced by the strength performances of the top layer lamina than that of the laminae for base materials. Bending MOR showed the higher values in tulip wood that was hardwoods than in larch wood that was softwoods regardless of the strength performances of the top layer laminae, and it was found that the values were much influenced by the strength performances of the base materials used in the core and bottom layers. However these values were 1.4-2.5 times higher values than the bending strength of the wooden floorboards specified in KS, it was found that it can be sufficiently applied to the base materials of wooden floorboards in place of plywood.

• Journal of Microbiology and Biotechnology
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• 제8권6호
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• pp.650-655
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• 1998

The chromosomal DNA fragment from Phaffia rhodozyma CBS 6938 which is able to autonomously replicate in the yeast Saccharomyces cerevisiae was cloned on an integrative URA3 plasmid. Its minimal fragment exhibiting autonomously replicating activiy in the S. cerevisiae gave a higher frequency transformation efficiency than that found for centromere-based plasmid, and enabled extrachromosoma1ly stable transmission of the plasmids in one copy per yeast cell under non-selective culture condition. The 836-bp DNA element lacked an ORF and did not contain any acceptable match to an ARS core consensus. Sequence analysis, however, displayed a cluster of three hairpin-Ioop-sequences with individual $\triangle {G_{25}}^{\circ}C$ free energy value of -10.0, -17.5, and -17.0 kcal. $mor^{-l}$as well as a 9-bp sequence with two base pair mismatches to the S. cerevisiae/E. coli gyrase-binding site. This 836-bp sequence also included one 7-bp sequence analogous to the core consensus of centromeric DNA element III (CDEIII) of S. cerevisiae, but CDEIII-like 7 bp sequence alone did not give a replicative function in this yeast.

• 한국가축번식학회지
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• 제20권1호
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• pp.77-84
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• 1996

본 연구는 배양액의 삼투압과 비타민이 체외 배발생에 미치는 영향을 조사하기 위하여 소의 미성숙 난포란을 체외성숙 및 수정 후 무단백 한정배양액에서 체외배양하였다. 0.35mM phosphate와 19종 아미노산이 포함된 무단백 한정배양액의 삼투압을 NaCl농도에 의하여 달리하였을 때 소 수정란의 발생능력은 265mOsm과 290mOsm에서 유의적으로 증가하였다(p<0.05). 수정 후 120시간에 5.56mM포도당이 포함된 새로운 배양액에서 배발생을 계속시켰을 때 상실배는 290mOsm과 315mOsm에서 유의적으로 증가하였으며, 배반포는 290mOsm배양액에서 유의적으로 증가하였다. Glutamine과 아미노산이 첨가된 배양액에서 비타민은 소수정란의 발생에 영향을 미치지 않았다.

• Journal of the Korean Wood Science and Technology
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• 제29권2호
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• pp.76-83
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• 2001

춘재부와 추재부로 분리한 일본삼나무재 시험편을 이용하여 목재의 목리방향에 평행하는 압축응력에 대한 목재의 역학적 거동을 관찰하였다. 그 결과, 춘재와 추재간에는 역학적 거동의 차이가 있었는데, 춘재는 하나의 연륜내에서 거의 동일한 세포벽율을 나타내며 응력의 증가에 대하여 변형이 직선적으로 증가하였다. 그러나 한 연륜내에서 수에서 수피방향으로 세포벽율이 점차 증가하는 추재부에서는 응력의 증가에 따라 변형량이 더 커져서 곡선적으로 증가하는 경향을 나타내었다. 또한 하중속도가 변화할 때 종적탄성율의 하중속도 의존성은 춘재부와 추재부에서 비슷하게 나타났다. 추재부의 종압축강도와 종압축탄성율은 춘재부의 약 4백의 수치를 나타내었다.

• Journal of the Korean Wood Science and Technology
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• 제22권1호
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• pp.44-53
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• 1994

This research was carried out to investigate the effect of paper sludge addition on formaldehyde emission, and physical and mechanical properties of UF-particleboard. In order to investigate the effect of paper sludge addition to resin, particleboards were bonded with urea-formaldehyde resins containing 5, 10, 15% paper sludge powders of three types(A Type: -200 mesh, B Type: -100~+200 mesh. C Type: -50~+100 mesh), based on weight of resin solid. Also the effect of paper sludge addition to furnish was studied from particleboards fabricated with ratios of sludge to particle of 5:95, 10:90, 15:85 based on oven-dry weight. Tests were conducted on the manufactured particleboards to determine formaldehyde emission, bending properties, internal bond strength and thickness swelling. The obtained results were summarized as follows: The addition of paper sludge powder to resin yielded a higher pH of cured resin. Formaldehyde emission decreased with the increase of paper sludge powder addition to resin and paper sludge composition ratio to furnish. Particleboard bonded with urea-formaldehyde resin containing paper sludge powder and particleboard mixed with paper sludge have similar bending properties(MOR, MOE) and thickness swelling compared with control particleboard. Internal bond strength of particleboards treated with paper sludge were lower than that of control particleboard. The use of paper sludge as scavenger was achieved reduction of formaldehyde emission without depression of physical and mechanical properties of particleboard. Also the use of paper sludge was able to concluded that there is possibility of partial substitution of wood particle materials.

• Journal of the Korean Wood Science and Technology
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• 제44권3호
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• pp.315-322
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• 2016

2개 이상의 보부재 집성재 요소들의 측면접착으로 제작된 "블록접착집성재"는 대단면 목조건축물의 건축부재로 활용 가능한 구조용재다. 블록접착집성재의 측면은 접착제의 종류와 도포량 및 압체압력을 각기 다른 조합으로 접착하여 박리시험과 전단블록시험으로 접착성능을 검토하였다. 실험결과 레조시놀접착제 $500g/m^2$을 도포하고 압체압력 1.5 MPa의 조건으로 제작된 블록접착집성재의 측면접착성능이 가장 양호하였다. 양호한 측면접착조건으로 제작된 블록접착집성재는 동일단면계수의 대조군 집성재와 휨 강도 성능을 비교 검토하였다. 블록접착집성재의 휨 탄성계수는 대조군 집성재와 유사하였으며, 파괴계수는 대조군집성재 보다 27% 향상되었다. 할렬은 대조군집성재 보다 블록접착집성재에서 다량 발생하였으며, 블록접착집성재의 측면접착층에서 계면파괴나 응집파괴는 관찰되지 않았다.