• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.237-248
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• 2018

The vertical distribution of hydrometeor before precipitation near the cloud base has been analyzed using a scanning lidar, rawinsonde data, and Cloud-Resolving Storm Simulator (CReSS). This study mostly focuses on 13 Desember 2016 only. The typical synoptic pattern of lake-effect snowstorm induced easterly in the Yeongdong region. Clouds generated due to high temperature difference between 850 hPa and sea surface (SST) penentrated in the Yeongdong region along with northerly and northeasterly, which eventually resulted precipitation. The cloud base height before the precipitation changed from 750 m to 1,280 m, which was in agreement with that from ceilometer at Sokcho. However, ceilometer tended to detect the cloud base 50 m ~ 100 m below strong signal of lidar backscattering coefficient. As a result, the depolarization ratio increased vertically while the backscattering coefficient decreased about 1,010 m~1,200 m above the ground. Lidar signal might be interpreted to be attenuated with the penetration depth of the cloud layer with of nonspherical hydrometeor (snow, ice cloud). An increase in backscattering signal and a decrease in depolarization ratio occured in the layer of 800 to 1,010 m, probably being associated with an increase in non-spherical particles. There seemed to be a shallow liquid layer with a low depolarization ratio (<0.1) in the layer of 850~900 m. As the altitude increases in the 680 m~850 m, the backscattering coefficient and depolarization ratio increase at the same time. In this range of height, the maximum value (0.6) is displayed. Such a result can be inferred that the nonspherical hydrometeor are distributed by a low density. At this time, the depolarization ratio and the backscattering coefficient did not increase under observed melting layer of 680 m. The lidar has a disadvantage that it is difficult for its beam to penetrate deep into clouds due to attenuation problem. However it is promising to distinguish hydrometeor morphology by utilizing the depolarization ratio and the backscattering coefficient, since its vertical high resolution (2.5 m) enable us to analyze detailed cloud microphysics. It would contribute to understanding cloud microphysics of cold clouds and snowfall when remote sensings including lidar, radar, and in-situ measurements could be timely utilized altogether.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.71-79
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• 2018

This study was conducted to compare the physicochemical properties of newly developed artificial medium and conventional plug medium and to investigate the proper irrigation interval to produce the high quality tomato seedlings. The five existing artificial media (organic medium coir, mixed medium Tosilee and Q plug, and inorganic medium LC and rockwool) and four newly developed artificial medium (mixed medium TP-S1 and inorganic medium PU 14-S1, PU-7B, and PU 15-S1) were used to grow tomato 'Yegwang' with irrigation interval of one-day (14 times), two-day (7 times), and three-day (5 times) for 14 days. The pH was the significantly highest in the PU 15-S1. All growing medium measured were in the range of pH 5.17-6.90. EC was the highest in the Q plug. The initial germination rate was the highest in the PU 15-S1. The final germination rate and mean daily germination were not significantly different in all growing medium except for the PU 14-S1. Growth of tomato seedlings at 15 days after sowing was the greatest in the Q plug. At 29 days after sowing, seedlings were also the greatest in the Q plug, followed by rockwool and PU-7B. Also, growth was better in the one-day interval treatment. As a result, we confirmed the applicability of the artificial medium to tomato plug seedlings in this experiment, and seedlings were the greatest in the Q plug. Therefor, it is considered that adding nutrients to the artificial medium of the newly developed medium PU-7B, and applying the irrigation one-day interval can produces high quality tomato seedlings similar to using Q plug.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.194-205
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• 1999

Hydrogeochemical variation and environmental isotope at the some abandoned metal mine (Sanggok, Keumsil, Jangpung and Samdeok) creeks of the Hwanggangri mining district were carried out based upon the physicochemical properties for surface water collected of February in 1998. Hydrogeochemical composition of the all water samples are characterized by the relatively significant enrichment of Ca$^{2}$, alkaline ions, N $O_3$$^{－}$ and Cl$^{－}$ in normal surface water, whereas the surface waters near the mining area are relatively enriched in Ca$^{2+$, Mg$^{2＋}$, heavy metals. HC $O_3$$^{－}$ and S $O_4$$^{2－}$. Surface waters of the mining creek have low pH, high EC and extremely high concentrations of TDS compared with surface water of the non-mining creeks. The range of $\delta$D and $\delta$$^{18}$O values (SMOW) in the waters are shown in －65.0 to－71.2$\textperthousand$ and －9.1 to－10.2$\textperthousand$. The d($\delta$D－$\delta$$^{18}$O) value with those of water samples ranged from 7.3 to 10.9. These $\delta$D and $\delta$$^{18/}$ of the acid mine water are more heavy values than those of surface water. The values have revealed the positive correlation between isotopic compositions and major elements, because those $\delta$D and $\delta$$^{18}$O values increase with increasing TDS. HC $O_3$$^{－}$ , S $O_4$$^{2－}$ and Ca$^{2＋}$ concentration. Using WATEQ4F, saturation index of albite calcite, dolomite and mostly clay minerals in water of the mining area show undersaturated and progressively evolved toward the equilibrium condition due to fresh water mixing, however, surface waters of the non-mining area are nearly saturated and/or supersaturated. Geochemical modeling showed that mostly toxic heavy metals within water in the mining creek may exist largely in the from of metal-sulfate (MS $O_4$$^{2－}$), free metal (M$^{2＋}$/), C $O_3$$^{－}$ and/or OH$^{－}$ complex ions. Based on the geology, water chemistry and environmental istopic data the water compositions from the Sanggok and Keumsil mine creek (consist mainly of Cambro-Ordovician carbonate rocks of the Cho-seon Supergroup) show higher PH, Ca$^{2＋}$, Mg$^{2＋}$ , HC $O_3$$^{－}$ and more heavy $\delta$D and $\delta$$^{18}$O values than those from the Jangpung and Samdeok mine creek (consist of age -unknown metasedimentary rocks of the Ogcheon Supergroup and/or Jurassic grani-toids), but each of these waters represents a similar hydrogeochemical evolution path by the mine water mixing.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.361-369
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• 1997

A microbiological nitrate determination method by E. coli is modified in Korea, using K12 wildtype, KCTC 1116, for the quantitative reduction of $NO_3{^-}$ to $NO_2{^-}$. The nitrate in plant, soil or water sample is determined spectrophotometrically after being diazotized with sulfaniamide and N-(1-naphthl)-ethlenediamine. The modified E. coli cell method and principle for nitrate determination using Korean wildtype E. coli strain is described, and cell culture and preparation of stock suspension for E. coli as well. This modified E. coli cell method can be managed simply and fast, it is suitable for the investigation of the large serials, it can be also automated and has a high degree of sensitivity up to 0.01ppm $NO_3{^-}-N$ in the sample solution. The applicability of the modified E. coli cell method has been tested for plant, soil and water analysis on a wide range of different samples. Recovery rates of added nitrate have been determined and comparisons with other standard nitrate analytical procedures have been carried out. The results with the modified E. coli cell method show high correlation ($r^2=0.98$) with those gained by the standard analytical procedures. The advantages and disadvantages of the method are also discussed to other nitrate determination methods.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.77-98
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• 1974

This study was carried out ill an attempt to investigate the properties and activities of sericin obtained from silk cocoon shells in silk reeling water through various instrumental analyses. In addition, the effects of the characteristics in sericin solubility on the reeling process and silk qualities were also studied on the basis of tile above conditions. The results obtained are as follows： I. The sericin properties and activities through various analytical instruments. 1. The water solubility of each amino acid such as serine, glycine. glutamic and aspartic acids against the pH modified water by using automatic amino acid analyzer, showed the lowest solubility at PH 5, but it increased according to drifting toward the alkalinity. 2. When the obtained sericin particles by water pH variation were observed with the electronic microscope, it was found for the sericin Particles to expand in the alkaline regions. 3. The IR spectrum results showed the differences among the pH modified sericin solutions at the range of 2,100cm-1 and 1.890cm-1 of wave number. 4. The existence of sericin with in silk fabrics made differences in the X-ray interference intencity, that is, the non-degummed fabrics had the interference peak at 2$\theta$=14$^{\circ}$, 17$^{\circ}$, 24$^{\circ}$, and the degummed ones had it at 2$\theta$=17$^{\circ}$, 18$^{\circ}$, 20$^{\circ}$, 23$^{\circ}$, 26$^{\circ}$. II. The results of sericin solubility for silk reeling process. 1. The sericin solubility and swelling had a tendency to increase up with high M-alkalinity and pH value of water. But in case of acidity. water hardness and concentration of ethylene glycol were high, the sericin solubility and swelling were decreased. 2. With the filature experiments, the best conditions of filature orator are summarized as fellows ; a. pH; 6.9${\pm}$0.2 d. acidity; below10ppm b. total hardness; 55：5ppm e. Fe ion; none c. M-alkalinity; 40${\pm}$10ppm

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.619-625
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• 2006

Background: Peripheral arterial disease is frequently accompanied with systemic arteriosclerosis and more than half of the cause of deaths is due to the development of coronary arterial disease. Moreover, it is known that the most frequent cause of death after a bypass surgery of chronic arterial obstruction is heart related complications. Especially in patients with atherosclerotic arterial obstruction in the lower extremities who had no history of heart disease or had no presenting symptoms of ischemic heart disease showed a high rate of postoperative mortality and for this reason we suggest preoperative evaluation in these patients to evaluate whether or not coronary arterial disease is accompanied. Material and Method: Since Feb. 2001 to Oct. 2004, we analyzed 52 patients who were operated on for atherosclerotic arterial obstruction in the lower extremities, with the exception of patients with a past history of heart disease or symptoms of ischemic heart disease. They underwent on the same day a coronary and femoral angiography for evaluation of accompanying coronary arterial disease. Of among these patients, we compared those who received bypass surgery of the arteries of the peripheral extremities alone to those who underwent combined coronary artery bypass surgery. Result: 63% of the reported cases of atherosclerotic arterial obstruction in the lower extremities were accompanied with coronary arterial disease. Old age, hypertension, diabetes mellitus, smoking, and hypercholesterolemia are known risk factors for arteriosclerosis and of these, only old age and hypertension had statistically significance in patients with severe atherosclerotic arterial obstruction in the lower extremities accompanied with coronary arterial disease. Diabetes, smoking, and hypercholesterolemia showed no statistical significance in this group. With the increase in severity of the range and the degree of atherosclerotic arterial obstruction, coronary arterial disease is frequently accompanied and its severity also increased. Patients who received both peripheral artery and coronary artery bypass surgery showed no difference in the period of hospitalization and ICU stay period compared with patients who received bypass surgery of the arteries of the lower extremities alone. Conclusion: Patients with atherosclerotic arterial obstruction in the lower extremities without symptoms of ischem to evaluate coronary arterial disease for active treatment, especially in the patients with old age, hypertension and high AVD scores.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.329-343
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• 2001

The deep environment and geochemical evolution of the Bugok geothennal waters, located in the Kyeongnam Province, was re-interpreted based on the hydrochemical and isotopic data published by Yun et al. (1998). The geothermal waters of the Bugok area is geochemically divided into three groups; Geothennal water I, II and III groups. Groups I and II are geochemically similar; high temperature (55.2-77.2$^{\circ}$C) and chemically belonging to Na-S04 types. However, pH and Eh values are a little different each other and Group II water is highly enriched in S04 compared to Group I water. Group III water, occurring from peripheral sites of the central part of the geothennal waters, shows temperature range of 29.3 to 47.0$^{\circ}$C and belongs to $Na-HCO_3-S0_4$ types. The deep environment and geochemical evolution of the Bugok geothennal waters, showing the diversity of geochemistry, can be interpreted as follows; I) Descending to great depth of meteoric waters that originated at high elevation and reacting with sediments and/or granites in depth. The $S0_4$ concentration of the waters has been increased by the dissolution of sulfate minerals in sediments. 2) During the continuous descending, the waters has met with the reduction environment, producing the $H_2S$ gas due to sulfate reduction. The waters has been heated up to 130$^{\circ}$C and the extent of water-rock reaction was increased. At this point, pH of waters are increased, S04 concentration decreased and calcite precipitated, therefore, the waters show the $Na-S0_4$ type. 3) Ascending of the geothennal waters along the flow path of fluids and mixing with less-deeply circulated waters. The $S0_4$ concentration is re-increased due to the oxidation of $H_2S$ gas and/or sulfide minerals in sediments. During continuous ascending, these geothennal waters are mixed with shallow groundwater.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.42-46
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• 2016

The radioactive iodine ($^{131}I$) presents in the environment through the excrete process of nuclear medicine patients. In the detecting of low level of $^{131}I$ in the public water, the counting uncertainty has an effect on the accuracy and reliability of detecting $^{131}I$ radioactivity concentration. In this study, the contribution of sample amount, radioactivity concentration and counting time to the uncertainty was investigated in the case of public water sample. Sampling points are public water and the effluents of a sewage treatment plant at Sapkyocheon stream, Geumgang river. In each point, 1, 10 and 20 L of liquid samples were collected and prepared by evaporation method. The HPGe (High Purity Germanium) detector was used to detect and analyze emitted gamma-ray from samples. The radioactivity concentration of $^{131}I$ were in the range of 0.03 to 1.8 Bq/L. The comparison of the counting uncertainty of the sample amount, 1 L sample is unable to verify the existence of the $^{131}I$ under 0.5 Bq/L radioactivity concentration. Considering the short half-life of $^{131}I$ (8.03 days), a method for measuring 1 L sample was used. However comparing the detecting and preparing time of 1, 10 L respectively, detecting 10 L sample would be an appropriate method to distinguish $^{131}I$ concentration in the public water.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.156-164
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• 2015

High temperature stress would affect rice production in the future as heat wave is expected to occur frequently under climate change conditions. The objective of this study was to obtain rudimentary information to assess the impact of heat stress on rice yield and its yield component in Korea. Two rice cultivars "Hwaseongbyeo" (Japonica) and "Dasanbyeo" (Tongil-type) were grown at different nitrogen fertilization levels in two seasons. These cultivars were grown in 1/5000a Wagner pot placed within four plastic houses where temperature was controlled at ambient, ambient$+1.5^{\circ}C$, ambient$+3^{\circ}C$ and ambient$+5^{\circ}C$ throughout the rice growing season in Suwon ($37^{\circ}16^{\prime}N$, $128^{\circ}59^{\prime}E$), Korea. The degree of temperature change affected grain yield whereas the level of nitrogen had little impact on grain yield. The number of panicle per pot and spikelet per panicle were not significantly different among temperature treatments in both cultivars tested. In contrast, 1000-grain weight and ripened grain ratio were decreased significantly under the treatments raising the air temperature to the level of $5.0^{\circ}C$ and $1.5^{\circ}C$ above the ambient air temperature in Dasanbyeo and Hwaseongbyeo, respectively. Reduction of 1000-grain weight and ripened grain ratio under the temperature treatments of $3.0^{\circ}C$ and $5.0^{\circ}C$ above the ambient air temperature resulted in significantly less grain yield for Dasanbyeo and Hwaseongbyeo, respectively. The greater sensitivity of grain yield to temperature increase in Dasanbyeo was attributable to the sharp decrease of 1000-grain weight and ripened grain ratio with the temperature rise above $23^{\circ}C$ during ripening period. On the other hand, Hwaseongbyeo had little variation of them in the temperature range of $23-27^{\circ}C$. These results suggested that grain yield would decrease under future climate conditions due to grain weight decreased by shorter grain filling period as well as the ripened grain ratio reduced by spikelet sterility and early abortion of rice kernel development. Thus, it would be essential to use cultivars tolerant to heat stress for climate change adaptation, which merits further studies for developing varieties that have traits to avoid spikelet sterility and early abortion of rice kernel, e.g., early morning flowering, under heat wave.