• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.305-310
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• 2004

The development of Myzus persicae (Sulzer) was studied at temperatures ranging from 15 to $32.5^{\circ}C$ under $70{\pm}5\%$ RH, and a photoperiod of 16:8 (L:D). Mortality of 1st-2nd nymph was higher than that of 3rd-4th nymph at the most temperature ranges whereas at high temperature of $32.5^{\circ}C$, more 3-4nymph stage individuals died. The total developmental time ranged from 12.4 days at $15^{\circ}C$ to 4.9 days at $27.5^{\circ}C$, suggesting that higher the temperature, faster the development. However, at higher end temperature ranges of 30 and $32.5^{\circ}C$, the development took 5.0 and 6.3 days, respectively. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were $4.9^{\circ}C$ and 116.5 day-degrees. The nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with pre-nymph, post-nymph, and total nymph stages in descending order. The coefficient of determination $r^2$ ranged between 0.87 and 0.94.

• Journal of Korean Society on Water Environment
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• v.30 no.5
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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.

• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.446-451
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• 2018

Effective ingredients were extracted using wheat sprout with high levels of flavonoids, and the extraction process was optimized with a central composite design model. The response value of the central composite design model establishes the extraction yield and the content of the flavonoids. The main and interactive effects were then analyzed depending on independent variables such as the extraction time, the volume ratio of alcohol to ultrapure water, and the extraction temperature. The extraction time and temperature were relatively large for the extraction yield. For the total flavonoids, the extraction time was most significantly affected. Considering both the extraction yield and the content of the total flavonoids, optimal extraction conditions were as follows: the extraction time (2.44 h), volume ratio of alcohol to ultrapure water (50.00 vol%), extraction temperature ($54.41^{\circ}C$). Under these condition, the extraction yield was 30.14 wt% and the content of the total flavonoids was $35.37{\mu}g\;QE/mL\;dw$. From the actual experimental result, the extraction yield under this condition was 29.92 wt% and the content of the total flavonoids was $35.32{\mu}g\;QE/mL\;dw$, which had an error rate of 0.39% and 0.74%, respectively. This is a multi-analysis comprehensive analysis that analyzes two simultaneous values of responses, but is considered to be highly accurate and also provides an excellent reliability of the optimization process in this study.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.211-216
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• 2003

Development and reproduction of Dichromothrips smithi were investigated under different temperatures, Durations of the development from egg to pre-adult of D. smithi were measured under 11 temperature ranges and it was 44.0 days at 13$^{\circ}C$ and 8.7 days at 32$^{\circ}C$. Developmental zero point and total effective temperature for the development of egg and larva, prepupa, pupa and for the complete development (egg to emergence) were 9.4, 8.9, 10.5, 10.8 and 9.5$^{\circ}C$, and 46.1, 90.1, 23.9, 41.2 and 204.4 degree days, respectively. The adult longevity was 28.3 days at 15 C and 14.3 days at 30$^{\circ}C$. The highest average fecundity per female was 69.3 at 25 C. The highest intrinsic rate of natural increase (r$\_$m/) and the highest net reproduction rate (R$\_$o/) were 0.241 at 30$^{\circ}C$ and 56.56 at 25$^{\circ}C$. The optimum temperature range for the growth of D. smithi was between 25$^{\circ}C$ and 30$^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.161-164
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• 1979

The effect of acidity and the metal surface area of the Pd loaded zeolite catalysts; prepared from $Ca^{2+}-,\;La^{3+}-,\;NH_4^+-$exchanged Y and dealuminated HY was studied for the reaction of n-butane. The amount of strong acid site determined by the temperature programmed desorption of ammonia increased in the order NaY < CaY < LaY. Total amount of acid site decreased with increasing degree of dealumination, but the portion of strong acid site increased with increasing $SiO_2/Al_2O_3$ ratio. The effective metal surface area determined by the CO adsorption technique was large for those zeolite catalysts having strong acidity. It was found that conversion of n-butane was strongly dependent on the acidity and the effective metal surface area of the catalysts. The fact that the conversion of n-butane was proportional to the effective metal surface area suggests that the dehydrogenation by metallic component is the primary step in the reaction of n-butane.

• Journal of Korean Academy of Nursing
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• v.4 no.2
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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.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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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 $({\phi} 1.2-1.2).$

• Journal of the Korean Society for Precision Engineering
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• v.12 no.3
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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.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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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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• 2006.11a
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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.