• 한국식품영양과학회지
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• 제30권3호
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• pp.395-402
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• 2001

Bacillus subtilis 돌연변이주 중 ${\gamma}-GTP$활성이 높은 SM-2와 SM-10을 융합시켜 획득한 융합주 중 ${\gamma}-GTP$활성이 높은 융합주 FG-21의 배양적 특성을 조사하였다. 융합주 FG-21에 의한 ${\gamma}-GTP$의 생산은 1% glycerol, 1% peptone, 0.1% citric acid, 5 mM $K_2HPO_4$, 1 mM $FeCl_3$, 1 mM $MgCl_2$, 1 mM $NH_4Cl$, pH 7.0의 배지에 의해 $37^{\circ}C$에서 36시간 배양했을 때 621 U/mL으로 최대한 활성을 보였다. 융합주 FG-21이 생산한 biopolymer A가 단백질함량이 38.4%이고 B. subtilis K-1이 생산하는 biopolymer B의 단백질함량은 19.3%로 융합주 FG-21이 생산하는 Biopolymer A보다 함량이 낮았다. 융합주 FG-21의 biopolymer가 모균주의 biopolymer B보다 단백질함량이 높은 것은 상대적으로 높은 ${\gamma}-GTP$활성이 높아서 생성된 PGA가 levan보다 함량이 많기 때문인 것으로 사료된다. 총당함량은 biopolymer A가 58.5%, biopolymer B가 76.5%로 나타났다. 융합주 FG-21과 모균주가 생산하는 biopolymer의 단백질함량과 총당함량비는 융합주 FG-21이 생성한 biopolymer는 38 : 59. 모균주가 생산한 biopolymer B는 19 : 78의 비율이었고 HPLC 분석에 의한 biopolymer A와 B의 fructose함량은 각각 537.7 mg/g biopolymer, 764.4 mg/g biopolymer으로 나타났다. Biopolymer A와 B의 glutamic acid함량은 각각 163.7 mg/g, 94.3 mg/g이었다. Biopolymer A와 B의 fructose와 glutamic acid의 함량비는 각각 78 : 22, 89 : 11의 비로 함유되어 있었다. 따라서 융합주에 의해 생산된 biopolymer는 모균주보다 구성상태가 변화된 biopolymer를 생산한 것으로 판단되어 fusion과 같은 균주개량을 통하여 물질의 구성적, 물질적 변화된 biopolymer를 생산할 수 있을 것이라 사료된다.

• Steel and Composite Structures
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• 제25권4호
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• pp.415-426
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• 2017

The thermo-mechanical vibration behavior of two dimensional functionally graded (2D-FG) porous nanobeam is reported in this paper. The material properties of the nanobeam are variable along thickness and length of the nanobeam according to the power law function. The nanobeam is modeled within the framework of Timoshenko beam theory. Eringen's nonlocal elasticity theory is used to develop the governing equations. Using the generalized differential quadrature method (GDQM) the governing equations are solved. The effect of porosity, temperature distribution, nonlocal value, L/h, FG power indexes along thickness and length and are investigated using parametric studies.

• 한국식품영양과학회지
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• 제41권5호
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• pp.655-660
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• 2012

밭마늘과 논마늘(영천산)의 매운맛 차이를 알아보고자, 마늘의 매운맛 생성에 관여하는 주요 인자들인 alliin과 allcin 그리고 SAC의 함량을 HPLC로 분석하고, 이들 함함성분의 생성에 관여하는 효소인 alliinase와 GTPase(${\gamma}$-glutamyl trans peptidase) 활성 및 pyruvate 생성량과 일반성분을 분석하였다. 수분함량은 논마늘이 밭마늘에 비하여 높았으며, 조회분, 조지방, 조단백, 탄수화물 함량 역시 밭마늘이 논마늘에 비하여 높았다. 마늘의 주요 매운맛 성분인 allicin 함량은 밭마늘이 $2.83{\pm}0.03$ mg/g, 논마늘이 $2.22{\pm}0.02$ mg/g을 나타내어 밭마늘이 논마늘에 비하여 유의적으로 높았다. Allicin의 전구체인 alliin의 함량은 밭마늘이 $8.97{\pm}0.09$ mg/g, 논마늘이 $8.22{\pm}0.08$ mg/g으로 나타났다. SAC 함량은 밭마늘이 $1.74{\pm}0.17$ mg/g으로, 논마늘의 $1.04{\pm}0.14$ mg/g에 비하여 유의적으로 높았다. 한편, 효소 alliinase 활성도는 밭마늘이 $285{\pm}43{\mu}mole/mg$ protein, 논마늘이 $239{\pm}34{\mu}mole/mg$ protein을 나타내어 유의적인 차이는 없었으나, GTPase 활성은 밭마늘이 86.3 ${\mu}mole/mg$ protein으로 논마늘의 78.4 ${\mu}mole/mg$ protein에 비하여 높게 나타내었다. 이상의 결과를 토대로 밭마늘이 매운 맛이 강한 것은 본 연구결과로부터 allicin 함량이 논마늘에 비하여 높은 데 기인된 것으로 파악되었다. 밭마늘은 논마늘에 비하여 alliinase 활성은 유사하였으나 alliin의 함량이 높아 allicin 생성량이 많았으며, SAC가 높고 GTPase의 활성이 높아 alliin의 함량이 높은 것으로 생각되었다. 따라서, 마늘을 기능성 식품소재로의 활용을 극대화하고자 한다면 밭마늘이 논마늘보다 더 적합한 것으로 생각된다.

• Preventive Nutrition and Food Science
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• 제4권4호
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• pp.241-245
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• 1999

The potential of hydroponic cultivated Chinese cabbage as a kimchi material was evaluated. The hydroponic-grown (HG) Chinese cabbage was heavier in weight, taller in height, wider in width, but less in number of leaves compared with the field-grown (FG) Chinese cabbage. The former showed higher contents of calcium, iron, vitamin A and niacin, and lower lipid and vitamin C than the latter. During fermentation of 28 days at 1$0^{\circ}C$, FG and HG kimchis showed comparable pH and acidity values, besides that the FG and HG kimchis showed a pH value of 4.2 and 4.0, respectively, at the 14th day. The FG kimchi showed higher numbers of total microbes as well as total and typical lactic acid bacteria than the HG kimchi at the 7th day. However, both kimchis did not show any difference at 14th day. There was no significant difference in the {TEX}$L^{*}${/TEX} value between FG and HG kimchis. However, HG kimchi showed a more reddish hue than FE kimchi between the 7th and 14th day of fermentation. In sensory evaluation, the HG kimchi revealed a slightly more sour taste and a less crispy texture than the FE kimchi at the 14th day. However, both kimchis did not show any difference in overall quality until the 21st day of fermentation.

• 대한의생명과학회지
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• 제24권4호
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• pp.390-397
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• 2018

For the specific detection of human Parvovirus B19 (HuPaV-B19), we designed ten specific PCR primers from 3,800~4,500 nucleotides of HuPaV-B19 complete genome (NC_000883.2). Seventeen candidate PCR primer sets for specific detecting HuPaV-B19 were constructed. In specific reaction of HuPaV-B19, seventeen PCR primer sets showed specific band, however five PCR primer sets were selected basis of band intensity, amplicon size and location. In non-specific reaction with seven reference viruses, four PCR primer sets showed non-specific band, however one PCR primer set is not. Detection sensitivity of final selective PCR primer set was $100fg/{\mu}L$ for 112 minute, and PCR amplicon is 539 base pairs (bp). In addition, nested PCR primer set was developed, for detection HuPaV-B19 from a low concentration of contaminated samples. Selection of nested PCR primer set was basis of sensitivity and groundwater sample tests. Detection sensitivity of final selective PCR and nested PCR primer sets for the detection of HuPaV-B19 were $100fg/{\mu}L$ and $100ag/{\mu}L$ basis of HuPaV-B19 plasmid, it was able to rapid and highly sensitive detection of HuPaV-B19 than previous reports. We expect developed PCR primer set in this study will used for detection of HuPaV-B19 in various samples.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.636-640
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• 2000

Cup-plant (Silphium perfoliatum L.) has potential to produce high biomass and highly digestible forage in the wetlands where other productive forages do not grow or produce well. However, high moisture content at harvest is a considerable disadvantage of cup-plant for the production of high quality silage. This study was conducted to determine the effect of moisture content on the characteristics of cup-plant silage. Harvested cup-plant was ensiled in farm scale plastic bag silos and laboratory silos. In the plastic bag silos, first growth (FG) and regrowth (RG) cup-plant was harvested, wilted and ensiled. Dry matter content of FG and RG was 280 g/kg and 320 g/kg after 48 hr of wilting. The silage made with FG had pH 5.3 and 5.63 g/kg DM of acetate as a major volatile fatty acid. The composition of lactate, butyrate and acetate production was 1.0: 0.9: 2.3. The pH of silage made with RG was 4.5 and lactate was a major fermentation end product (16.8 g/kg DM). In the laboratory silos, wilted and unwilted first growth cup-plant material was ensiled to compare the early fermentation end products at days 2, 4, 11, and 40. Wilting increased dry matter content by 42% in the harvested material. Wilted silage showed about one unit lower pH until day 11. The contents of ammonia nitrogen and acetate were higher in un wilted silage, while that of lactate was higher in wilted silage (p<0.05). Butyrate and propionate were not detected in the wilted silage until day 40. We conclude from the results that moisture control is essential for the production of high quality cup-plant silage and high pH of cup-plant silage is due to low concentrations of fermentation end products.

• 설비공학논문집
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• 제13권8호
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• pp.796-802
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• 2001

The purpose of the present study is to examine the heat transfer characteristics of the U-shape heat pipe for the cooling of semiconductor in subway train. Perflouro-carbon(PFC) was used as working fluid. Temperature distribution on the surface and heat transfer coefficients were investigated according to the working fluid volume percent and heating rate. The results were as follows; Optimum volumetric percent of working fluid was from 80% to 90%, and hat transfer coefficients of evaporation and condensation were as follows, respectively. $\hbar_ie=0.37\times(\frac{P_i}{P_O})$l_c}^0.3$,$\hbar_ic-4.2(\frac{\kappa_l^3p_l^2gh_fg}{\mu_lq_c_l_c}^\frac{1}{3}

• 한국임상수의학회지
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• 제15권1호
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• pp.140-145
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• 1998

The present study was carried out for the rapid and accurate detection of Anaplasma marginale in cattle using Polymerase Chain Reaction. One pair of primer, BAP-2 and AL34S, were designed to amplify a 409 Up fragment of the A marginale membrane surface protein encoding beta($msp{\beta}l$) gene with a hilly sensitive and specific PCR. A marginale isolated from naturally infected calf in Chonbuk area were used to obtain target genomic DNA for PCR. This study showed that a 409 bp of $msp{\beta}l$ gene fragment could be detected as little as 15 fg of purified A marginale genomic DNA. The amplified fragment with PCR was checked for the identification of $msp{\beta}l$ gene by enzyme restriction and sequencing. Also, the target DNA extracted directly from blood were used in the PCR reactions without prior purification to shorten the detection time. The PCR in the present study was considered convenient and rapid method for the detection of A marginale in whole blood of infected cattle.

• Earthquakes and Structures
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• 제24권4호
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• pp.237-245
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• 2023

Based on novel Galerkin's technique, the theoretical study gives a prediction to estimate the vibrations of FG rotating cylindrical shell. Terms of ring supports have been introduced by a polynomial function. Three different laws of volume fraction are utilized for the vibration of cylindrical shells. Variation frequencies with the locations of ring supports have been analyzed and these ring supports are placed round the circumferential direction. The base of this approach is an approximate estimation of eigenvalues of proper functions which are the results of solutions of vibrating equation. Each longitudinal wave number corresponds to a particular boundary condition. The results are given in tabular and graphical forms. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing length-to-radius ratio. There is a new form of frequencies is obtained for different positions of ring supports, which is bell shaped. Moreover, on increasing the rotating speed, the backward frequencies increase and forward frequencies decreases.

• 한국식품저장유통학회지
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• 제16권4호
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• pp.459-462
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• 2009

단감 '부유' 품종은 저장 단감의 대부분을 차지하고 있다. 저장중 발생하는 과정부갈변 현상과 과피흑변 현상은 과일의 상품성 저하의 주 원인이 되고 있으며, 과실내에서 칼슘함량이 상대적으로 낮은 부위에서 단감의 갈변이 발생하고 있다. 따라서 본 시험은 재배 중 토양관주 및 엽면시비가 토양 수체 및 과실내 칼슘 함량과 갈변발생에 미치는 영향을 알아보고자 실시하였다. 과실중 칼슘 함량은 Ca 엽면시비에서 칼슘 함량이 다른 처리구에 비해 가장 높게 나타났으며 다음으로 Ca + IBA 처리구와 Ca 관주 처리의 순으로 나타났다. 토양관주처리에 의한 흡수가 일정부분 이루어진 것으로 판단된다. 과일부위별 칼슘 함량은 경와부>적도면>과정부 순으로 나타나, 갈변이 주로 발생하는 부위인 과정부에서 가장 낮게 나타났다. 과일 특성 조사에서 당도, 경도, 중량은 처리간 뚜렷한 경향차를 보이지 않았다. 이후 저온 저장 후 상온 보관에서 1주일이 지났을 때 과정부갈변과 발생이 Ca 엽면시비에서 14%, Ca 관주에서 20%로 대조구의 50%에 비해 현저히 감소하는 경향을 보여주었다. 이상의 결과에서 토양관주처리와 엽면시비를 통해 토양, 엽 및 과실내 칼슘 함량이 증가함을 보여주었고, 특히 과실 과정부의 칼슘 함량의 증가로 저장중 과정부갈변이 크게 감소한 것으로 판단된다.