• International Journal of Industrial Entomology and Biomaterials
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• 제16권2호
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• pp.101-107
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• 2008

To improve mating rate of the bumblebee, Bombus terrestris, temperature, photoperiod and illumination during mating periods favorable for B. terrestris were investigated. The mating rate of queen mated at $19^{\circ}C$ was 92.1%, which was 2.1-5.9% higher than that of $22^{\circ}C$ and $25^{\circ}C$. $19^{\circ}C$ was more effective than at $22^{\circ}C$ and $25^{\circ}C$ in death rate during mating periods. The survival rate after hibernation of queen mated at $19^{\circ}C$ was 3.0-17.7% higher than that of $22^{\circ}C$ and $25^{\circ}C$. At the photoperiod regimes during mating periods, queen mated at 14 L was more effective than 12 L and 16 L in death rate during mating, survival rate after hibernation, and egg-characteristics. In case of illumination during mating periods, intensity of over 1000 lux was suitable for mating B. terrestris queen in colony development. Therefore, we supposed that mating temperature favorable for B. terrestris was $19^{\circ}C$ and photoperiod for mating was 14 L, and illumination was over 1000 lux.

• 한국안전학회지
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• 제9권4호
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• pp.29-41
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• 1994

High temperature tensiles tests, steady state creep tests, internal stress tests and creep rupture tests using Al 7075 alloy were performed over the temperature range of 9$0^{\circ}C$~50$0^{\circ}C$ and stress range of 0.64~17.2(kgf/$\textrm{mm}^2$) in order to investigate the creep behavior and predict creep rupture life From the apparent activation energy Qc and the applied stress exponent n measured, at the temperature range of 9$0^{\circ}C$~l2$0^{\circ}C$, the creep deformation seemed to be controlled by cross slip. On the other hand at the temperature of 20$0^{\circ}C$~23$0^{\circ}C$ the creep deformation seemed to be controlled by dislocation climb but at 47$0^{\circ}C$~50$0^{\circ}C$, by diffusion creep. And the rupture life(t$_{f}$) might be represented by anthermal process attributed to the difference of the applied stress dependence of Internal stress and the ratio of the Internal stress to the applied stress, the thermal activated process attributied to the temperature dependence of the internal stress. Also the ratio between stress dependence of primary creep rate and that of minimum creep rate was measured 0.46, the minimum creep rate is expected to be appromately obtained from master creep curve including the relationship primary creep rate and minumum creep rate. Finally the relationship new rupture parameter and logarithmic stress was represented with including the ratio between the dependence of primary creep rate and that of minimum creep rate, using the new rupture parameter the rupture life predition is exactly expected.d.

• 한국수산과학회지
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• 제28권5호
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• pp.589-598
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• 1995

본 연구는 수온과 크기의 영향을 포함하는 양식굴 C. gigas의 단위시간당 여과수량 산출식을 제시하였다. 여수율의 측정은 폐쇄순환계에서 지표물질의 농도 저감속도를 측정하는 간접법으로 수행되었으며, 지표물질은 배양한 규조류 Chaetoceros calcitrans를 사용하였고, 이 규조의 $chlorophyll-\alpha$양에 직선적으로 비례하는 675nm의 흡광도 값으로 부터 농도감소계수 Z를 구하고, Z를 감소율로 변환하여 수량 V에서 여수율 FR을 산출하였다. $Z=-In(\frac{C_t}{C_0})/t$, $FR=V{\codt}(1-e^{-z})$ 양식굴의 여수율은 다음과 같이 수온 및 개체건조 육중량을 변수로 하는 지수함수식으로 나타낼 수 있다. 여수율은 수온과 더불어 지수함수적으로 증가하며, 상한측 임계온도는 $28-29^{\circ}C$ 사이에 있는 것으로 여겨진다. $\frac{FR}{DW}$, 1/hr/g, dry meat wt = $Exp(0.208{\cdot}T-4.324){\cdot}(DW)^{-0.7771}$, FR, 1/hr/animal = $Exp(0.208{\cdot}T-4.324){\cdot}(DW)^{0.223}$

• 열처리공학회지
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• 제19권5호
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• pp.270-279
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• 2006

The effects of eight types of spheroidizing annealing conditions including annealing temperature, annealing time, cooling rate, and furnace atmosphere on the microstructure and hardeness were determined in SCM440 steel which has been widely used for automotive parts. The well-spheroidized structure and minimum hardness were obtained when the steel was heat-treated at $770^{\circ}C$ for 6 hours, cooled to $720^{\circ}C$ at a cooling rate of $24^{\circ}C/h$, and then kept for 7 hours at the $720^{\circ}C$ followed by air cooling. In order to increase the productivity and to save the manufacturing cost, it is desirable to apply a faster cooling rate to the spheroidizing annealing. It was found that a cooling rate of $100^{\circ}C/hr$ was the fastest cooling rate applicable to the SCM440 steel among the four cooling rates used in this study. The microstructure consisted of ferrite and very fine spheroidized cementite when the steel was annealed for 13 hours at $720^{\circ}C$ below $A_{C1}$ temperature. This was caused by the short annealing time and the retarding effect of Cr and Mo on both the dissolution of pearlite to cementite and coarsening of spheroidized cementite. The steel heat treated in air showed the decarburized layer of about $125{\mu}m$ in thickness at the surface.

• 한국세라믹학회지
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• 제35권12호
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• pp.1329-1336
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• 1998

A twt -step carbothermal reduction scheme has been employed for the synthesis of SiC whiskers in an Ar or a H2 atmosphere via vapor-solid two-stage and vapor-liquid-solid growth mechanism respectively. It has been shown that the whisker growth proceed through the following reaction mechanism in an Ar at-mosphere : SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) the third reaction appears to be the rate-controlling reaction since the overall reaction rates are dominated by the carbon which is participated in this reaction. The whisker growth proceeded through the following reaction mechaism in a H2 atmosphere : SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) The first reaction appears to be the rate-controlling reaction since the overall reaction rates are enhanced byincreasing the SiO vapor generation rate.

• 한국동물학회지
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• 제29권3호
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• pp.201-207
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• 1986

소금쟁이 (Gerris paludum insuralis)성체의 호흡률을 $25^\\circ C, 30^\\circ C, 35^\\circ C$ 및 $40^\\circ C$에서 암, 수별로 각각 1시간동안 매 5분간격으로 산소소비율을 측정하여 다음과 같은 결론을 얻었다. (1) $30^\\circ C$에서는 시간경과에 따른 산소소비량의 변화가 다른 온도군에 비해 매우 적었으며, 첫 5분간과 마지막 5분간의 양이 거의 비슷하여 생활적온으로 판단되며, 그 외의 온도에서는 시간경과에 따라 단위시간당 산소소비량은 주기적인 감소상을 나타내었다. (2) 산소소비율은 대체로 수컷이 암컷보다 많았다. (3) 산소소비량은 $25^\\circ C, 30^\\circ C, 35^\\circ C$ 및 $40^\\circ C$에서 각각 0.42, 0.49, 0.79 및 1.11 $\\mu$l/mg/hr로서 온도가 높아짐에 따라 증가하였다. (4) $Q_10$은 수컷에서는 $25^\\circ C \\sim 35^\\circ C$의 온도간격에서 높았고, 암컷은 $30^\\circ C \\sim 40^\\circ C$의 온도간격에서 높았다. 평균 $Q_10$은 2.12였다. (5) 생체량 10 mg, 건조중량 5 mg이상에서는 체중이 높을수록 산소소비량은 감소하였다. (6) 호흡정지고온과 호흡정지저온은 각각 $48.31^\\circ C$와 $17.68^\\circ C$였다. (7) $30^\\circ C$를 제외한 세 온도군에서 호흡이 정지되는 시간은 약 110분 후로 추정되었다.

• Nuclear Engineering and Technology
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• 제8권4호
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• pp.203-207
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• 1976

질칼로이-4에 있어서 flow stress strain rate 의존성을 냉간가공 및 소둔된 시편에 대해 20$0^{\circ}C$-45$0^{\circ}C$ 온도 구간에서 응력이완 실험으로 조사하였다. 전체 실험온도에서 In-3-ln i 관계식은 $10^{-5}$-$10^{-3}$ sec$^{-1}$ strain rate의 구간에 걸쳐 선형관계를 보였다. 냉간 가공된 질칼로이 -4의 strain rate sensitivity, m값은 30$0^{\circ}C$에서 최소값을 보인 반면, 소둔된 시편의 경우 30$0^{\circ}C$와 45$0^{\circ}C$에서 최소값들을 보였다. 최소값의 m이 나타나는 온도는 가공시효값이 극대값을 보이는 온도와 일치한다는 사실이 확인되었다. m값의 감소는 활동자유전위들이 산소원자에 의해 pinning된 결과로 유발되는 가공 시효와 관련된 것으로 고려된다. 그리고 소둔된 시편이 45$0^{\circ}C$에서 가지는 최소 m값은 철 원자들로 인한 가공 시효에서 기인된 것으로 생각된다.

• 대한미생물학회지
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• 제21권2호
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• pp.261-270
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• 1986

A total of 339 urethral, vaginal swab and eye discharge materials from the out-patients in the hospitals of Seoul area was microbiologically collected for the detection of Chlamydia trachomatis infection during May through August, 1985. McCoy cell culture system (MCC) and enzyme-likned immunosorbent assay (EIA) methods were employed in this study as the tools for the detection of C. trachomatis, and the detectabilities of two methods were compared. The results obtained in this study are summarized as follows: 1. The positive rate of C. trachomatis in 339 swab specimens was 18.6%, and the rate in females (20.1%) was much higher than that in males (7.1%). 2. The positive rate of C. trachomatis infection the prostitutes was the highest (24.2%), and the rate in the eye discharge specimens obtained from the new barns was 12.8%. 3. The positive rates of C. trachmoatis infection detected in the specimens from the patients with vaginitis and leucorrhea, with infertility, with cystitis and with nongonococcal urethritis were 17.2%, 21.9%. 18.0% and 7.1%, respectively. 4. The positive rate of C. trachomatis infection in 20-25 age group was 30.5%. This rate was the highest among the other age groups. 5. The positive rate of C. trachomatis infection in the randomly screened 89 swab specimens by EIA (30.3%) was much higher than the rate detected by MCC (18.6%). 6. The positive rate of C. trachomatis infection in females detected by EIA was also much higher than in males, and the 20-25 age group showed the highest positive rate as compared to the other age groups. 7. Sensitivity and specificity of EIA for the detection on C. trachomatis were 100% and 88.6%, respectively, in case that MCC was regarded as perfect method. In summarizing the above results, it is known that considerable cases with genital diseases and with eye discharges were associated with C. trachomatis, and that EIA method is recommendable for the detection of C. trachomatis especially in the specimens swabed from the genital tracts.

• 한국식품과학회지
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• 제19권5호
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• pp.451-452
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• 1987

취반온도가 밥의 저장($4^{\circ}C$, 72시간)중 노화속도에 미치는 영향을 조사하였다. 취반온도($100{\sim}120^{\circ}C$)가 올라갈수록 밥의 노화속도는 감소하였다. 노화시간 상수(속도상수의 역수)는 $110^{\circ}C$ 및 $120^{\circ}C$에서 취반한 밥이 $100^{\circ}C$의 밥보다 각각 1.2 및 1.5배 큰 값을 보였다. 취반온도가 올라갈수록 밥의 저장중 노화될 수 있는 물질의 양 및 노화된 물질의 양은 모두 감소하였다.

• 한국세라믹학회지
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• 제35권12호
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• pp.1336-1336
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• 1998

2단계 열탄소환원법으로 탄화규소 휘스커를 Ar과 H2분위기에서 기상-고상, 2단계, 기상-액상-고상 성장기구를 통해 각각 합성하였다. Ar분위기에서 탄화규소 휘스커는 다음과 같은 반응기구로 성장하였다. SiO2(S)+C(s)-SiO(v)+CO(v) SiO(v)3CO(v)=SiC(s)whisker+2CO2(v) 2C(s)+2CO2(v)=4CO(v) 이때 전체 반응속도는 세번째 반응에 참여하는 탄소에 의해 지배되었다. 따라서 이 반응이 휘스커 합성의 율속반응으로 판단되었다. 한편 H2 분위기에서 탄화규소 휘스커는 다음과 같은 반응기구로 성장하였다.SiO2(s)+C(s)=SiO(v)+CO(v) 2C(s)+4H2(v)=2CH4(v) SiO(v)+2CH4(v)=SiC(s)whisker+CO(v)+4H2(v) 이때 전체 반응속도는 SiO(v) 기체의발생 속도에 의해 지배되었다. 따라서 첫번째 반응이 휘스커 합성의 율속 반응인 것으로 판단되었다.