• 한국응용곤충학회지
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• 제43권4호
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• pp.305-310
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• 2004

복숭아혹진딧물(Myzus persicae)의 온도별 발육상을 조사하기 위해 $15^{\circ}C$에서 $32.5^{\circ}C$까지 $2.5^{\circ}C$ 간격으로 8개 온도에서 조사를 하였으며, 상대습도는 $70{\pm}5\%$, 광주기는 16L:8D 조건으로 처리하였다. 일반적으로 진딧물의 약충 단계는 1령에서 4령가지로 구분하나 본 연구에서는 1-2령을 (1st-2nd nymph), 3-4령을(3rd-4th nymph)이라 하여 2단계로 구분하였다. 대부분의 온도에서 사망률은 초기 1-2령이 3-4령보다 더 높았으나 $32.5^{\circ}C$에서는 오히려 3-4령의 사망률이 대부분을 차지하였다. 온도별 발육기간은 $15^{\circ}C$에서 12.4일로 가장 길었고 온도가 상승함에 따라 점차 짧아져 $27.5^{\circ}C$에서는 4.9일로 가장 짧았으나 30에서 $32.5^{\circ}C$까지는 오히려 5.0일과 6.3일로 발육 기간이 길어지는 양상을 보였다. 약충의 발육영점온도는 $4.9^{\circ}C$이고, 유효적산온도는 116.5일도 이었다. 각 온도별 발육률은 변형된 Sharpe와 DeMichele의 비선형 모형에 잘 적합되었다. 발육단계별 발육기간을 표준화하여 누적시킨 값을 3개의 변수를 갖는 Weibull function에 적용하여 보았을 때 1-2령${\to}$3-4령${\to}$ 전체 약충 순으로 발육기간이 짧아지는 경향을 보여 주었고 $r^2$는 0.87-0.94로 나타났다.

• 한국물환경학회지
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• 제30권5호
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• pp.539-548
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• 2014

This study was carried out to investigate algal community structures and their correlations with environmental factors on five weir areas in the Nakdong River, South Korea. Water qualities, hydrodynamics, meteorological conditions and algal species compositions were observed in studied sites from May 2010 to Dec. 2013. Results showed that average total phosphorus concentration of 2013 was decreased by 52.4% in comparing with that from 2010 to 2011. Chlorophyll.a concentrations were positive significant with water temperature, pH, total phosphorus and total nitrogen, but is not significant with turbidity and suspended solids. Seasonal successions of algae were observed that Stephanodiscus sp. was dominant species with 65.3% of dominant frequency in studied site. Large algal biomass of the low temperature-adapted diatoms were observed during temperature range of $4{\sim}9^{\circ}C$, but large cyanobacterial biomass mainly during high temperature period ranged from $22^{\circ}C$ to $32^{\circ}C$. Microcystis sp. dominated during high water temperature in summer. The yearly correlations of algal biomass with accumulated solar radiations were not significant but seasonal correlations of summer from June to August were significant with correlation coefficient 0.33 (p<0.05). There were not significant correlations between turbidities and algal biomass. Turbidity and suspended solids concentrations were not significant correlation with algal biomass. According to the results, algal communities had strong correlation with water temperature and had partially correlation with solar radiation. For an effective management of algal blooms, water managers should survey with more long-term monitoring of various environmental factors and algal communities.

• 공업화학
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• 제29권4호
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• pp.446-451
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• 2018

플라보노이드성분 함량이 높은 밀싹을 이용하여 유효성분을 추출하고, 중심합성계획모델을 이용하여 추출공정을 최적화하였다. 중심합성계획모델의 반응치로는 추출수율과 플라보노이드성분 함량을 설정하고, 독립변수인 추출시간, 주정/초순수 부피비, 추출온도에 따른 주효과도와 교호효과도를 해석하였다. 추출수율의 경우 추출시간과 추출온도가 상대적으로 큰 영향을 미쳤으며, 플라보노이드성분 함량의 경우에는 추출시간의 영향이 가장 크게 나타났다. 추출수율과 플라보노이드성분 함량을 모두 고려한 결과 최적추출조건은 추출시간(2.44 h), 주정/초순수의 부피비(50.00 vol%), 추출온도($54.41^{\circ}C$)이었으며, 이때 추출수율은 30.14 wt%, 플라보노이드성분 함량은 $35.37{\mu}g\;QE/mL\;dw$이었다. 이 조건의 실제 실험결과 추출수율(29.92 wt%), 플라보노이드성분 함량($35.32{\mu}g\;QE/mL\;dw$)으로 오차율은 각각 0.39%, 0.74%이었다. 이는 두 개의 반응치를 동시에 분석하는 다중분석 종합분석임에도 높은 정확도를 나타낸 것으로 본 연구에서의 최적화과정 신뢰도가 우수한 것으로 사료된다.

• 한국응용곤충학회지
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• 제42권3호
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• pp.211-216
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• 2003

최근 국내에 유입된 해충으로서 시설재배 난을 가해하는 난총채벌레(Dichromorhrips smithi)의 발육생태 및 생식을 구명할 목적으로 온도별 알, 유충, 전용, 용의 발육기간, 성충수명 및 산란수를 조사하였다. 알에서 우화까지의 발육기간은 13$^{\circ}C$에서 44.0일이고, 32$^{\circ}C$에서 8.7일이었다. 온도가 높을수록 짧은 발육기간을 보였다. 알, 유충, 전용, 용, 알에서 우화까지의 발육영점온도와 유효적산온도는 각각 9.4$^{\circ}C$, 8.9$^{\circ}C$, 10.5$^{\circ}C$, 10.8$^{\circ}C$, 9.5$^{\circ}C$ 그리고 46.1, 90.1, 23.9, 41.2, 204.4일도이었다. 암컷 성충수명은 15$^{\circ}C$에서 28.3일이고 3$0^{\circ}C$에서 14.3일로 온도가 높을수록 짧았으며, 암컷 한 마리당 산란수는 $25^{\circ}C$에서 69.3개로 가장 많았다. 내적자연증가율(r$_{m}$ )은 3$0^{\circ}C$에서 0.241, 1세대당 순증식율(R$_{o}$ )은 $25^{\circ}C$에서 56.56로 가장 높았다. 결과적으로 난총채벌레의 성장에 적합한 온도범위는 25-3$0^{\circ}C$이었다.

• 대한기계학회논문집
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• 제18권2호
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• pp.389-396
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• 1994

It is very important to clarify the ignition and flame propagation processes of methanol fuel in the Spark-ignition engine. High speed Schlieren photography and pressure trace analyses were used to study on combustion characteristics of methanol fuel in a constant volume chamber. Methanol-air mixtures equivalence rations from lean limit to 1.4 were ignited at initial pressure (0.1, 0.3, 0.5 MPa), temperature (313 343, 373 K) and ignition energy (40, 180 mJ). As the result of this study, we verified the characteristics such as ignition delay, effective thermal efficiency, flame propagation velocity, lean limit, ignitability and combustion duration. Obatained results are as follows. (1) The time to 10% reach of maximum pressure was 40-50% of the total combustion duration for this experimental condition hardly affected by equivalence ratio. (2) The Effective thermal efficiency, as calculated from maximum pressure was the highest when the mixture was slightly lean $({\phi} 0.8-0.9)$ and maximum pressure was the highest when the mixiture was slightly rich $({\phi} 1.2-1.2).$

• 한국정밀공학회지
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• 제12권3호
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• pp.42-52
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• 1995

An UBET(Upper Bound Elemental Techniquel) program has been developed to analyze forging load, die-cavity filling and effective strain distribution for flashless non-axisymmetric forging. To analyze the process easily, it is suggested that the deforma- tion is divided into two different parts. Those are axisymmetric part in corner and plane- strain part in lateral. The total power consumption is minimized through combination of two deformation parts by building block method, form which the upper-bound forging load, the flow pattern, the grid pattern, the velocity distribution and the effective strain are deter- mined. To show the merit of flashless forging, the results of flashless and flash-forging processes are compared through theory and experiment. Experiments have been carried out with plasticine billets at room temperature. The theoretical predictions of the forging load and the flow pattern are in good agrement with the experimental results.

• 대한화학회지
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• 제23권3호
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• pp.161-164
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• 1979

$Ca^{2+},\;La^{3+},\;NH_4^+$ 등으로 양이온을 교혼하거나, 알루미늄을 추출한 합성 zeolite Y에 팔라듐을 담지시켜, 촉매산성도 및 담지된 금속의 유효표면적을, n-butane의 분해반응에서 촉매활성과 관련지어 조사하였다. 암모니아의 TPD(Temperature Programmed Desorption) 실험에 의하면 NaY < CaY < LaY 순으로 강한 산점의 양이 많아졌으며, 알루미늄 추출로 $SiO_2/Al_2O_3$의 비가 커질 수록 전체산점의 양은 감소되었으나, 강한 산점의 양은 증가되었다. CO의 화학흡착으로 측정한 담지금속의 유효표면적은 산성도가 큰 촉매에서 비교적 컸다. n-Butane의 zeolite 촉매에서의 반응은, 촉매의 산성도와 금속성분의 유효표면적에 관계되나, 전화율이 측정한 범위내에서의 유효표면적에 비례하므로 금속성분에 의한 탈수소반응이 중요한 단계로 생각된다.

• 대한간호학회지
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• 제4권2호
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• pp.44-56
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• 1974

Very few studies regarding the effects of preoperative nursing intervention on children's welfare after surgery have been conducted. The purpose of this study was 1) to evaluate the effects of preoperative nursing instructions on children's physical recovery and emotional state after surgery and 2) to analyse the relationship between the effects of preoperative nursing instructions and the age and general anxiety of child. The study was conducted flow: August 15th to October 30th at Severance Hospital, Seoul, Korea. A total of 41 Pediatric surgical Patients, between the age of 4 to 14, participated in the study. Twenty patients, randomly selected, were visited by the experimenter in the evening before, surgery and received specific preoperative nursing instructions. These instructions were designed to alleviate emotional stress and were adopted to the age of child. The postoperative recovery of these patients were then compared with a randomly selected control group of 21 patients who received only the routine preoperative care by the staff in the hospital Dependent variable were vomiting, pain medication, ability to void, elevation of temperature, infection, the between surgery and hospital discharge and postoperative emotional stress which was measured by the vital signs. Because of the limitation of the sample size it was difficult to obtain valid statistical results. However, the analysis of the raw data indicates that: 1) the preoperative nursing instructions appears to promote physical recovery and it seems especially effective in preventing elevation of temperature and shortening the length of the hospital stay, 2) the preoperative nursing instruction also seems to be effective in relieving the child's emotional stress(situational anxiety) after surgery, 3) the patient's general anxiety level preparatively seems to be a predictor of postoperative problems, 4) the preoperative nursing instructions were an effective means of promoting physical recovery in every age group as long as the child understood the instructions. The above data would seem to indicate that all preoperative pediatric patients four years of age or older, if they can understand, should have preoperative nursing instruction in order to alleviate postoperative stress and enhance physical recovery. The level of general anxiety preparatively deserves special attention since the amount of nursing instruction needed seems to vary with tile level of anxiety.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.178-181
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• 2008

Cylindrical stainless-steel/sodium heat pipe for a high-temperature application was manufactured and tested for transient and steady-state operations. The container material was made of stainless-steel 316, and the working fluid was sodium. Stainless-steel 316 mesh screen was inserted as a capillary structure. The working fluid fill charge ratio was approximately 64 $\sim$ 181% based on the pore space of the wick. The outer diameter of the heat pipe was 12.7 mm and the total length was 250 mm. The evaporator part was 150 mm and the condenser 80 mm. The performance test of the heat pipe has been conducted in the furnace with up to 800 W. The variation of the average heat transfer coefficient was investigated as a function of heat flux and vapor temperature. As input thermal load increased, it was showed that difference of temperatures in evaporator and condenser decreased and that operating section and heat transfer characteristics at the heat pipe increased.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.32-35
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• 2006

The validation of a groundwater source heat pump system installation site is estimated by bydrogeothermic model ing. The hydraulic characteristics of the aquifer system is evaluated from pumping and recovery tests. In addition, the temperature distribution by the pumping and the injection of groundwater, and water level fluctuations are simulated by numerical modeling. The total cooling and heating load for the building is designed as 120RT(refrigeration ton) and the ground water source heat pump system covers 50RT as a subsidiary system The scenario of heat pump operation is organized as pumping and inject ion of groundwater that is performed for 8 hours per day in cooling mode for 90 days during the summer season The heat transfer by the injected warm water is limited near the inject ion wells in the simulated temperature distribution. The reason is that the given operation time is too short to expect broad thermal diffusion in large volume of the aquifer in the simulation time The simulated groundwater level and temperature distribution can be used as important data to develope an energy effective pumping and injection well system. Also it will be very useful to evaluate the hydraulic capacity of a target groundwater reservoir.