• 한국미생물·생명공학회지
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• 제17권6호
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• pp.556-562
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• 1989

The bioconversion of mandarin orange peel press liquor to single cell protein (SCP) by two yeast strains, F-60, and C-7, which were isolated from mandarin orange peel was carried out and compared with that of using Candida utilis IFO 0598. Experiments were directed toward the high yield of biomass and high protein in cultures of the strains mentioned above. Candida utilis IFO 0598, F-60 and C-7 strains were cultivated at 3$0^{\circ}C$, pH 5.2 for 3 days in shaking flasks. The effects of some nutrients on cell growth were studied. Cell mass and protein content per cell mass were increased by addition of urea 1%, KH$_2$PO$_4$ 0.1% and MgSO$_4$ㆍ7$H_2O$ 0.05%, When the F-60 strain cultured under the optimal conditions, cell mass, growth yield and protein content were 41.2g/l, 53.9%, 59.7%, respectively. Cell mass was also increased up to 15% by modifying the fermentation condition on the bench type 20l jar fermentor. Crude fat content (10.3%) of dried C-7 cell was higher than those of C. utilis and F-60, 4.9% and 5.6% respectively. Total protein content of the F-60 strain was 59.7% per dry weight. And we compared their amino acid compositions with that of FAO provisional pattern. In the case of the F-60 strains, amino acid contents such as lysine, leucine and isoleucine were much higher than those of methionine, cystine and tryptophan.

• 대한수의학회지
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• 제36권2호
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• pp.395-403
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• 1996

Monoclonal antibodies(MAbs) against field isolates of the bovine rotavirus A strain(G6), V strain(G10) and reference I-801 strain(G8) were produced and characterized. Six MAbs(4C2, 4D9, 5E1, 5E7, 5D5, 3E4) against A strain had neutralizing activity and reacted only with the G6 bovine rotaviruses determined by fluorescence focus neutralization (FFN) test. Otherwise, five neutralizing MAbs(1G2, 2G6, 5E2, 5E12, 5H7) against I-801 strain neutralized the G6 and G8 bovine rotaviruses. Five non-neutralizing MAbs(5F12, 7F12, 5E11, 2A11, 2B12) were VP6-specific and cross-reacted with all bovine and porcine rotaviruses examined by fluorescence antibody(FA) test. None of the MAbs reacted with bovie viral diarrhea virus(BVDV) and bovine coronavirus(BCV) determined by FA and FFN test.

• 한국지반공학회논문집
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• 제32권12호
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• pp.15-22
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• 2016

본 연구에서는 Strain wedge 해석모델을 이용하여 수평하중이 작용하는 단말뚝의 극한수평저항력 산정식을 제안하였다. 저항특성은 쐐기 후면부의 수평저항토압, 쐐기 측면부의 전단저항, 그리고 말뚝과 지반의 마찰저항으로 구분하였고, 이들의 합으로써 극한수평저항력을 산정하였다. 제안된 식을 기존의 쐐기 이론과 현장실험, 유한차분법과비교 분석하였다. 그 결과 제안식의 값이 기존의 쐐기 이론과 1.03%, 현장실험과는 0.40~3.32%, 유한차분법과는 6.02%의 차이를 보였다.

• International Journal of Concrete Structures and Materials
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• 제9권1호
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• pp.1-20
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• 2015

This work is devoted to the study of fresh and hardened properties of concrete containing recycled gravel. Four formulations were studied, the concrete of reference and three concretes containing recycled gravel with 30, 65 and 100 % replacement ratios. All materials were formulated on the basis of S4 class of flowability and a target C35 class of compressive strength according to the standard EN 206-1. The paper first presents the mix design method which was based on the optimization of cementitious paste and granular skeleton, then discusses experimental results. The results show that the elastic modulus and the tensile strength decrease while the peak strain in compression increases. Correlation with the water porosity is also established. The validity of analytical expressions proposed by Eurocode 2 is also discussed. The obtained results, together with results from the literature, show that these relationships do not predict adequately the mechanical properties as well as the stress-strain curve of tested materials. New expressions were established to predict the elastic modulus and the peak strain from the compressive strength of natural concrete. It was found that the proposed relationship E-$f_c$ is applicable for any type of concrete while the effect of substitution has to be introduced into the stress-strain (${\varepsilon}_{c1}-f_c$) relationship for recycled aggregate concrete. For the full stress-strain curve, the model of Carreira and Chu seems more adequate.

• 한국잠사곤충학회지
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• 제48권2호
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• pp.61-67
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• 2006

천잠의 우량형질 선발을 위하여 실내와 야외에서 사육하면서 수정율, 부화율, 용화율, 전견중 등을 비교 조사하였다. 실내사육 결과, 유충체색에 있어서 강건성은 담록체색이 우수하였으나, 견질은 암록체색이 우수한 것으로 나타났다. 전견중에 따라 분리된 등급간에는 약간의 차이가 인정되었다. 또한 $F_1$ 교잡종은 수정율과 부화율은 원종보다 떨어졌으나, 용화율과 견질 등에서 잡종강세효과가 확인되었으나 $F_2$ 교잡종은 효과가 인정되지 않았다. 야외사육의 경우 실내사육에 비해 감잠비율은 낮으나 유실잠이 많은 경향을 보였다. 또한 전견중, 전층중 및 견층비율 등 견질성적 이 실내사육보다 우수하였다.

• The Plant Pathology Journal
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• 제36권4호
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• pp.355-363
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• 2020

Bacterial traits for virulence of Ralstonia solanacearum causing lethal wilt in plants were extensively studied but are not yet fully understood. Other than the known virulence factors of Ralstonia solanacearum, this study aimed to identify the novel gene(s) contributing to bacterial virulence of R. solanacearum. Among the transposon-inserted mutants that were previously generated, we selected mutant SL341F12 strain produced exopolysaccharide equivalent to wild type strain but showed reduced virulence compared to wild type. In this mutant, a transposon was found to disrupt the murI gene encoding glutamate racemase which converts L-glutamate to D-glutamate. SL341F12 lost its motility, and its virulence in the tomato plant was markedly diminished compared to that of the wild type. The altered phenotypes of SL341F12 were restored by introducing a full-length murI gene. The expression of genes required for flagella assembly was significantly reduced in SL341F12 compared to that of the wild type or complemented strain, indicating that the loss of bacterial motility in the mutant was due to reduced flagella assembly. A dramatic reduction of the mutant population compared to its wild type was apparent in planta (i.e., root) than its wild type but not in soil and rhizosphere. This may contribute to the impaired virulence in the mutant strain. Accordingly, we concluded that murI in R. solanacearum may be involved in controlling flagella assembly and consequently, the mutation affects bacterial motility and virulence.

• Preventive Nutrition and Food Science
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• 제18권4호
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• pp.273-279
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• 2013

Protease widely exists in the digestive tract of animals and humans, playing a very important role in protein digestion and absorption. In this study, a high protease-producing strain Planomicrobium sp. L-2 was isolated and identified from the digestive tract of Octopus variabilis. The strain was identified by physiological and biochemical experiments and 16S rDNA sequences analysis. A protease was obtained from the strain Planomicrobium sp. L-2 through ammonium sulfate precipitation, dialysis and enrichment, DEAE-Sephadex A50 anion-exchange chromatography, and Sephadex G-100 gel chromatography. The molecular weight and properties of the protease were characterized, including optimum temperature and pH, thermal stability, protease inhibitions and metal ions. According to our results, the protease from Planomicrobium sp. L-2 strain designated as F1-1 was obtained by three-step separation and purification from crude enzyme. The molecular weight of the protease was 61.4 kDa and its optimum temperature was $40^{\circ}C$. The protease F1-1 showed a broad pH profile for casein hydrolysis between 5.0~11.0. No residual activity was observed after incubation for 40 min at $60^{\circ}C$ and 60 min at $50^{\circ}C$. F1-1 protease was inhibited by $Mn^{2+}$, $Hg^{2+}$, $Pb^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ ions, as well as PMSF, indicating that the protease F1-1 was a serine protease. Additionally, research basis provided by this study could be considered for industrial application of octopus intestinal proteases.

• 한국응용곤충학회지
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• 제43권1호
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• pp.43-48
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• 2004

2000년 8월 충남 부여의 장미 재배지에서 채집한 점박이응애가 etoxazole에 대해 3,700배의 저항성을 나타내었다. 이 집단을 실내에서 3년 동안 etoxazole로 100회 이상 도태하여 5,000,000배 이상의 저항성계통을 얻었다. 이 계통은 약제처리 없는 조건 하에서 1년 이상 경과된 후에도 암컷 성충의 etoxazole에 대한 저항성 수준은 변화가 없었다. 이 저항성계통의 유전과 교차저항성 유무를 조사하였다. 감수성계통 수컷과 저항성계통 암컷을 상호 교배( $R_{♂}$${\times}$ $S_{♂}$)하여 얻은 $F_1$과 $F_2$의 우성도는 각각 0.98과 0.98로 완전우성이었으며, $S_{♀}$${\times}$ $R_{♂}$으로 상호 교배하여 얻은 $F_1$과 $F_2$의 우성도는 각각 -0.97과 -0,68로 불완전열성이었다. 따라서 etoxazole저항성을 지배하는 유전인자는 수컷보다 암컷성충에 의존하여 완전우성에 의해 지배되는 것으로 나타났다. 이 저항성 성충은 acequinocyl과 emamectin benzoate에 대해 각각 10.4배와 14.0배의 교차저항성을 나타내었고, 알은 milbemectin, amitraz, pyridaben에 대해 각각 52.0배, 14.6배, 9.4배의 교차저항성을 나타내었다. 한편 카바제이트계 살비제인 bifenazate에 대해서는 역상관 교차저항성을 나타내었으므로, etoxazole에 저항성을 보이는 농가에서는 bifenazate를 교호살포하면 점박이응애를 효율적으로 방제할 수 있을 것이다

• 수산해양기술연구
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• 제20권1호
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• pp.1-5
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• 1984

고기가 자망에 이망될 숙건하에 그물면에 작용하는 붕어(Carassius carassius)의 유영력을 시험수조에서 strain gauge를 써서 즉정한 결과는 다음과 같다. 1. 순간최대유영력 및 지속최대유영력과의 체중과의 관계는 F 하(M) =1.45W, F 하(s) =0.29W 이다. 2. 순관최대유영력 및 지속최대유영력과의 체중과의 관계는 F 하(M) =0.11L 상(2.63), F 하(S) =0.15L 상(1.77)이다. 3. 붕어의 유체저항계수는 C 하(s) ≒0.287이다.

• 한국응용곤충학회지
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• 제33권4호
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• pp.230-236
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• 1994

실내에서 사육한 점박이응애(Tetranychus urticae Koch)의 감수성계통(S)을 유기염소계 살비제안인 dico-fol을 공시하여 인위적으로 도태선발하여 저항성 발달과 저항성 유전을 조사하고, 교차저항성 유무를 검토하였다. Dicofol을 150회 처리하여 얻은 선발계통($R_d$$LC_{50}$값이 27.5배증가하였다. 감수성계통과 저항성계통의 상호교배에서 얻어진 $F_1$ (R♀, XS♂, R♂, XS♀)은 농도와 사망률 관계에서 감수성 차이가 있었다. 또 $F_1$ (R♀, XS♂, R♂, XS♀)의 우성도는 암컷성충에서 각각 -0.29, -0.72, 수컷성충에서 각각 -0.42, -0.93로 나타났다. 따라서 dicofol 저항성 유전자는 불완전열성에 의해 지배되는 것으로 판단되었다. $R_d$ 계통 은 아미트라즈계인 amitraz에 대해서 높은 교차저항성을 나타내었고, 또한 pyethroid 계 살비제인 acrinathrin, bifenthrin에 대해서도 교차저항성을 나타내었다. Abamectin, chlofenson, clofente-zine, cyhexatin, fenbutation oxide, fenpyroximate, hexythiazox, monocrotophos, propargite, tetradifon에 대해서는 비교차저항성을 나타내었다. 한편 유기주석계인 azocyclotin과 fenbutatin oxide에 대해서느 역상관교차저항성을 나타내었다.