• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.1
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• pp.44-57
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• 2003

Seasonal variations of bacterial abundance and production, heterotrophic nanoflagellate (HNF) abundance and HNF ingestion rates on bacteria using FLB together with environmental variables were investigated at intervals of a month in Kyeonggi Bay from December 1991 to November 1998. Bacterial abundance and production ranged from 0.38$\times$10$^{9}$ ~ 3.25$\times$10$^{9}$ cells 1$^{-1}$ (average 1.19$\pm$0.69$\times$10$^{9}$ cells 1$^{-1}$ ) and from 1.51 to 20.4 cells 1$^{-1}$ h$^{-1}$ (average 6.04$\pm$ 1.88$\times$10$^{6}$ cells 1$^{-1}$ h$^{-1}$ ), respectively. Bacterial abundance and production showed no differences at the high tide and low tide, and bacterial abundances were not different with depth, but bacterial production decreased with depth. Seasonal variation of bacterial abundance showed almost similar fluctuation pattern to those of DOC (dissolved organic carbon). HNF abundances ranged from 388 to 4,374 cells ml$^{-1}$ (average 1,344$\pm$130 cells ml$^{-1}$ ), were high in March, April, July and August. HNF abundance showed no difference between the high tide and low tide, and was not different with depth. The ingestion rates of HNF on bacteria were 1.0 to 6.3$\pm$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ (average 3.12$\pm$0.55$\times$10$^{6}$ bacteria 1$^{-1}$ h$^{-1}$ ), resulting ingestion rates of HNF removed 19.4 to 141.4 %(average 62.3$\pm$12.0%) of bacterial production. Ingestion rates and grazing pressure of HNF on bacteria showed high correlation with HNF abundance. Although we cannot exactly discussion about seasonal variation of bacteria community in this study area where physical and chemical parameters were very complex, the results indicate that bacterial abundance and production were mainly controlled by resources supply as dissolved organic carbon and chlorophyll-a(bottom-up) except March which bacterial abundance and production uncoupled chlorophyll-a because of low dissolved organic carbon and low temperature, and were controlled by HNF grazing pressure(top-down) in the warm seasons except the winter.

• Economic and Environmental Geology
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• v.19 no.spc
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• pp.193-206
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• 1986

A number of auriferous veins occur in the Precambrian metamorphic terrain from Chungju to Mugeug district. These gold (-silver) deposits consist mainly of the fissure-filling quartz veins intruding the Precambrian gneiss or schist and Jurassic or Cretaceous granite. These gold (-silver) deposits can be 'divided into two mineralization epochs, (a) gold-rich veins related to Daebo igneous activity, and (b) gold-silver veins related to Bulgugsa igneous activity. These two groups of ore deposits with different generation can be characterized by the mode of occurrence of ore vein and the ore mineral associations. The auriferous quartz veins of Taechang and Boryeon mines associated with late Jurassic igneous activity are massive in character, and show the simple mineral assemblages and low Ag/Au ratio in the ores, representing a single mineralization system. The ore minerals are predominantly quartz containing minor or trace amonts of pyrrhotite, sphalerite, galena, pyrite, chalcopyrite and electrum. Electrum is closely associated with pyrrhotite and has chemical compositions from 61.4 to 78.5 atomic % Au. Fluid inclusion data suggest that ore minerals were deposited at temperatures between 238 and $390^{\circ}C$ from $CO_2$-rich fluids. The gold and/or silver-bearing quartz veins of Geumwang mine related to middle Cretaceous igneous activity are characterized by the multistage history, diverse mineral assemblages with high Ag/Au ratio in the ores. The ores of Geumwang mine have two contrasting mineral assemblages (1) pyrite+galena+sphalerite+arsenopyrite+electrum+argentite, representing the higher gold mineralization, and (2) pyrite+chalcopyrite+ galena +sphalerite+ arsenopyrite+silver sulfosalts+ electrum+ native silver+argentite, representing the higher silver mineralization. Electrum is closely associated with pyrite and has chemical compositions from 11.2 to 49.9 atomic % Au. The depositional environment during the higher gold mineralization can be estimated as the range of both temperature and sulfur fugacity, T= $200{\sim}300^{\circ}C$, log f ($S_2$) = $10^{-10}{\sim}10^{-15}$. The higher silver mineralization may be interpreted to have formed a range of falling temperature ($150{\sim}200^{\circ}C$) and low sulfur fugacity($10^{-10}{\sim}10^{-15}$). These temperature data are consistent with homogenization temperatures of fluId inclusions in quartz. Thus, the gold veins related to the Daebo igneous activity may be formed by the environment of higher temperature and pressure than the gold-silver veins associated with the Bulgugsa igneous activity.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.521-525
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• 2006

Korean ginseng was heat treated at various temperatures (110, 120, 130, 140 and $150^{\circ}C$) and times (1, 2, 3, 4, and 5 hr). The heat treated ginseng extract was analyzed for the total polyphenol content, total flavonoid content, DPPH free-radical scavenging, 5-HMF and ginsenoside. The total phenolics and flavonoid content increased with increasing treatment temperature and time. The highest total phenolics content was 29.46 mg/g (d.b) in $150^{\circ}C$ for 1hr (control: 2.68 mg/g). The highest total flavonoid content was 4.75mg/g (d.b) in $150^{\circ}C$ for 2hr (control: 0.39 mg/g). The antioxidant activity increased until $140^{\circ}C$ for 3 hours. An extension of the treatment time did not have any effect, and the antioxidant activity decreased at temperatures higher than $150^{\circ}C$ for more than 2 hours. The content of ginsenoside $Rg_1$, Re, $Rb_2$ and Rb3 rapidly decreased with increasing treatment temperature and time. Ginsenoside $Rg_3$ and $Rh_2$ were newly produced, or their contents increased with increasing treatment temperature and time.

• Atmosphere
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• v.26 no.2
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• pp.347-356
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• 2016

Radiosonde is an observation equipment that measures pressure (geopotential height), temperature, relative humidity and wind by being launched up from the ground. Radiosonde data which serves as an important element of weather forecast and research often causes a bias in a model output due to accuracy and sensitivity between the different manufacturers. Although Korean Meteorological Administration (KMA) and several institutes have conducted routine and intensive radiosonde observations, very few studies have been done before on the characteristics of radiosonde performance. Analyzing radiosonde observation data without proper understanding of the unique nature of those sensors may lead to a significant bias in the analysis of results. To evaluate performance and reliability of radiosonde, we analyzed the differences between two sensors made by the different manufacturers, which have been used in the campaign of Experiment on Snow Storm At Yeongdong (ESSAY). We improved a couple of methods to launch the balloon being attached with the sensors. Further we examined cloud-layer impacts on temperature and humidity differences for the analysis of both sensors' performance among various weather conditions, and also compared daytime and nighttime profiles to understand temporal dependence of meteorological sensors. The overall results showed that there are small but consistent biases in both temperature and humidity between different manufactured sensors, which could eventually secure reliable precisions of both sensors, irrespective of accuracy. This study would contribute to an improved sounding of atmospheric vertical states through development and improvement of the meteorological sensors.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.3
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• pp.236-247
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• 2011

This study investigates sea level (SL) rise due to global warming in the Northwestern Pacific (NWP) and Seas around the Korean peninsula (KP) using outputs of IPCC AR4 climate models. Particularly, components of the SL rise induced by a local steric effect, which was not considered in most climate models, were computed using model-projected 3-dimensional temperature and salinity data. Analysis of the SL data shows that the ratio of the SL rise in the NWP and KP was about two times higher than that in global mean and particularly the ratio in the Kuroshio extension region was the highest. The SL rises over 100 years estimated from MPI_ECHAM5 and GFDL_CM2.1 model by A1B scenario considering the thermosteric effect were 24 cm and 28 cm for the NWP and 27 cm and 31 cm for the Seas around the KP, respectively. Statistical analysis reveals that these SL rises are caused by the weakening of the Siberian High in winter as well as variations of pressure system in the NWP and by the resultant change of water temperature. It also found that the highest SL rise in the Kuroshio extension region of the NWP was connected with the large increase of water temperature in this area.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.48-54
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• 1997

Among the various vegetables eggplant and gourd family can stand against high temperature environmental condition, about 35$^{\circ}C$. However, most of greenhouse farmers are giving up crop cultivation during hot summer season due to extreme temperature, 4$0^{\circ}C$ or above, condition of greenhouse interior. To improve this inferior crop growth condition, for nozzle system was installed in the pet greenhouse and the effect of fog system was investigated in order to determine fog water amount and the required fog nozzle numbers according to house volumes. MEE fog nozzle was selected for this Investigation which can produce water particle size of 27${\mu}{\textrm}{m}$ with water amount of 100$m\ell$ at pumping pressure of 70kg/$\textrm{cm}^2$. House cooling test was conducted in the pet greenhouse with one minute fogging and one minute air ventilation without stopping. It maintained 32$^{\circ}C$ at the house interior when the atmosphere and the house temperature were 35 and 4$0^{\circ}C$, respectively. And, an experimental equation was developed through calculating the changes of relative humidity and temperature with psychrometric equation which revealed the moisture transfer pattern between the house air and fog system. It showed that the required water fogging amounts to reduce 1$0^{\circ}C$, 40 to 3$0^{\circ}C$, needs 80.7$\ell$ for 1-2W(8,350㎥) and 99.9$\ell$ for 3-2G-3S(10,330㎥) type greenhouse with particle size of 27${\mu}{\textrm}{m}$.

• Design & Manufacturing
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• v.13 no.2
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• pp.17-21
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• 2019

In this study, selective laser sintered 3D printing mold core and metal core were used to investigate the difference of the thickness shrinkage from the gate of the injection molded part at a constant interval. SLS 3D printing mold core was made of nylon-based PA2200 powder and the metal core was manufactured by conventional machining method. As the PA2200 powder material has low strength, thermal conductivity and high specific heat characteristics compared with metal, molding conditions were set with the consideration of molten temperature and injection pressure. Crystalline resin(PP) and amorphous resin(PS) with low melting temperature and viscosity were selected for the injection molding experiment. Cooling time for processing condition was selected by checking the temperature change of the cores with a cavity temperature sensor. The cooling time of the 3D printing core was required a longer time than that of the metal core. The thickness shrinkage of the molded part compared to the core depth was measured from the gate by a constant interval. It was shown that the thickness shrinkage of the 3D printing core was 2.02 ~ 4.34% larger than that of metal core. In additions, in the case of metal core, thickness shrinkage was increased with distance from the gate, on the contrary, in the case of polymer core showed reversed aspect.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.237-244
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• 2009

We investigated the effects of acupuncture stimulation on pulse wave variables and heart rate variability (HRV) in healthy adults. To evaluate twenty healthy volunteers (10 men, 10 women) had acupuncture into both Hapkok (Ll4) and Taechung (Liv3) for 15 minutes. Radial pulse, Heart Rate Variability, body temperature and blood pressure were checked before and after acupuncture to evaluate Pulse Wave Variability and Autonomous Function. The results were as follows; Heart rate was significantly increased while systolic blood pressure (mmHg) and diastolic blood pressure (mmHg) were significantly increased after acupuncture treatment. Sixteen subjects didn't change representative pulse wave variables after acupuncture treatment. Energy, height of main peak (H1), height of pre-dicrotic valley (H2) and height of descending valley (H4) were decreased while height of dicrotic peak (H5) was significantly decreased after acupuncture treatment. Time to main peak (T1), time to pre-dicrotic valley (T2), time to dicrotic peak (T5), total time (T) and T-T4 were decreased while time to descending valley (T4) was increased after acupuncture treatment. Total area (At), area of main peak (Aw) and ratio of diastolic period area (Ad) were decreased while ratio of systolic period area (As) and angle of main peak (MPA) were increased after acupuncture treatment. The standard deviation of all normal RR intervals (SDNN) was increased while the root mean square of successive differences between the normal heart beats (RMSSD) was significantly increased after acupuncture treatment by time domain analysis. Low frequency power (LF) and LF/HF ratio were decreased while high frequency power (HF) was significantly increased after acupuncture treatment by frequency domain analysis. This study suggests that acupuncture treatment changes pulse wave variability and heart rate variability. Further study on various acupuncture treatment for pulse wave variability and heart rate variability is required.

• Journal of Chest Surgery
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• v.8 no.2
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• pp.135-142
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• 1975

Total body perfusion using Sarns Heart-Lung-Machine, five head pump motor system with Travenol disposable bubble oxygenator was attempted in the dogs by the hemodilution method with total prime of buffered Hartman`s solution under moderate hypothermia. The first of all, the functions of Sarns Heart-Lung-Machine and effects of the hemodilution perfusion by buffered Hartman`s solution was studied. At the same time the changes of pressure of artery and vein, gas contents of the blood, and influence on the blood pictures were observed before, during, and after perfusion in 1-2 days. Hemodilution rates were the ranges of 85.0ml/kg to 97.3ml/kg and perfusion flow rates were maintained with the average 80. 5ml/kg/min [the ranges of 73.3ml/kg/min to 92.8ml/kg/min]. Hypothermia was employed between $35^{\circ}C$ and $31^{\circ} of the esophageal temperature. The total body perfusion was continued for 50-60 minutes. In the total cardiopulmonary bypass, atriotomy, ventriculotomy, and atrioventriculotomy were performed respectively. Arterial pressure was ranged approximately between 50 mmHg and 140 mmHg, but generally, it was maintained over 75 mmHg. Venous pressure was measured between 3.8 cm$H_2O$ and 16.0 cm$H_2O$. Optimum oxygenation could be achieved when oxygen flow into the oxygenator was maintained approximately at 5. 5L/min. In this way, the $pO_2$, $pCO_2$, and oxygen saturation were measured before, during, and afterperfusion in 1-2 days. The $pCO_2$ ranged approximately between 26.0 mmHg and 38.5 mmHg, but generally, it was maintained in the average 30.9-32.5mmHg. The $pO_2$ was ranged between 73.0mmHg and 332.2 mmHg, but it was maintained in the average 103.0-219.0 mmHg. Oxygen saturation was measured over 95. 0% during and after extracorporeal circulation respectively. Erythrocyte count, hemoglobin, hematocrit, and leucocyte count were decreased to 49.2%, 49.0%, 49.4%, and 21. 1% of the preoperative value during extracorporeal circulation respectively and these reductions were not recovered until 1-2 days after perfusion. These. resulted from relatively high degree of hemodilution rate and operative bleeding during these experimental studies. The platelets count was also decreased about to 71% during perfusion, on the contrary, it was increased progressively after perfusion and in 1-21 days after perfusion, the value was returned to preoperative contro1 level. Three dogs were all recovered after extracorporeal circulation.

• Food Science and Preservation
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• v.15 no.6
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• pp.847-851
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• 2008

The handling and processing of agricultural products in Korea is done manually. Small plastic boxes, nets, and corrugated cardboard boxes are used as containers during harvesting, sorting and other product handling operations. However, these practices are labor-intensive, time-consuming, require various kinds of packing materials, and are expensive because of high operating costs. To overcome these problems, the use of pallet bins with pre-cooling and storage features for handling and processing bulk farm products was investigated. The airflow resistances through bulk potato, onion and mandarin stocks were measured, and the pallet bins and a pressure pre-cooling device were manufactured. The opening ratio, bed depth and airflow rate through bulk potato, onion and mandarin in the pallet bin were defined with regression equations. The cooling rates of bulk potato, onion and mandarin were 0.8C/h ($21.7{\rightarrow}0C$, 14.5 h), 0.4C/h ($15.4{\rightarrow}.0C$, 32.2 h) and 0.7C/h ($13.7{\rightarrow}C$, 18.8 h), respectively, with the pressure pre-cooling system. Temperature deviances for storage of bulk potato, onion and mandarin were 0.12C, 0.12C and 0.17C, respectively.