• Korean Journal of Veterinary Research
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• v.12 no.1
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• pp.37-50
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• 1972

Another comparison of alveolar gas pressures, in a continuously rebreathing dog lung, with pulmonary arterial (mixed venous) blood, again showed alveolar pressures to be the higher for $CO_2$ and usually $O_2$ (positive ${\Delta}Pco_2$, and ${\Delta}Po_2$). ${\Delta}Pco_2$ was almost invariably positive, it was independant of time and of plasma pH changes produced by acid or bicarbonate infusion, but proportional to blood $CO_2$ level. It was seemingly little affected by the distribution or magnitude of blood flow nor did it result from failure of $CO_2$ equilibrium within the blood, but it did rise with carbonic anhydrase inhibition. ${\Delta}Po_2$ was more variable and sometimes negative, particularly at low blood flow rates. It seemed in dependant of time, and plasma pH changes, apart from an inverse relationship with that resulting from $CO_2$ changes. It existed despite considerable potential for gas exchange, and was unaffected by inhibition of the $CO_2$ reactions.

• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.44-52
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• 1980

Ionic dissociation rates of $\alpha$-chlorobenzyl ethyl ether in each solvent of toluene-$d_8$ and carbon tetrachloride were measured by the method of dynamic NMR spectroscopy. The spin system of these 1H NMR spectra was $AB_3$. The theoretical spectrum was calculated by computer simulation of dynamic NMR spectra, which agreed very well with observed spectra. From this computer simulation, the ionic dissociation rate constant k was obtained, and by Eyring plot with it, slope and intercept length was gained, from which kinetic parameters were calculated.The easiness of ionic dissociation depended upon solvent polarity. Activation enthalpy was 4.7 kcal/mole in toluene-$d_8$, 10.7 kcal/mole in carbon tetrachloride, and activation entropy was -35. 8 e.u. in toluene-$d_8$, -14.4 e.u. in carbon tetrachloride. It was understood that though the ${\Delta}H^{neq}$ value was small, this ionic dissociation had an easier procession in nonpolar solvents with increasing temperatures. Considering that the ionic dissociation could be thought as the first step of $S_N1$ mechanism, attention might be paid to the results that the value of ${\Delta}S^{neq}$ had a large negative value in comparison with a small ${\Delta}H^{neq}$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.761-772
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• 2015

Microfin tubes having an outside diameter (O.D.) of 7.0 mm are widely used in residential air conditioning systems and heat pumps. It is known that the mass fluxes for air conditioners and heat pumps under partial load conditions are several tens of $kg/m^2s$. However, literature surveys reveal that previous investigations were limited to mass flux over $100kg/m^2s$. In this study, we conduct R-410A evaporation heat-transfer tests at low mass fluxes ($50-250kg/m^2s$) using a 7.0 mm O.D. microfin tube. During the test, the saturation temperature was maintained at $8^{\circ}C$, and the heat flux was maintained at $4.0kW/m^2$. For comparison purposes, we also test a smooth tube with a 7.0 mm O.D. The results showed that the heat-transfer enhancement factor of the microfin tube increased as the mass flux decreased up to $150kg/m^2s$, which decreased as the mass flux further decreased. The reason for this was attributed to the change of the flow pattern from an annular flow to a stratified flow. Within the test range, the frictional pressure drops of the microfin tube were approximately the same as those of the smooth tube. We then compare experimental data obtained with the predictions obtained for the existing correlations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.207-212
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• 1980

Growth rates of oysters at four oyster farms in Hansan-Geoje Bay, near Chungmu, southern Korea, and density-dependent relative shell growth were investigated from November 1979 to May 1980 with the following results: The oysters at Sorang farm showed the best growth, the shell height in May 1980 attaining 10.10 cm, at Hwado 8.69cm and Songdo 8.57cm, all of which started growing in June 1979. At Chubong the oysters which started growing in July attained 8.6cm. The best grown oysters at Sorang shelved relatively slow growth in meat weight until February 1980, and then showed rapid growth upto May. At Hwado and Songdo they grew fast from December 1979 to February 1950, and from April to May 1980. Those at Chubong gradually increased growth rate from December 1979, and in April and May they showed rapid growth but still being smaller than the others. The ratio of meat weight to shell weight increased at Whado, Songdo and Chuhong after December 1979, but at Sorang it increased rapidly after February 1980. The ratio of shell length to shell height was 0.60 and up when the individual number of oysters attached to each cultch-disc(oyster shell) was less than 13, 0.56 to 0.60 when 14 to 25, and 0.51 or less when over 28, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.648-655
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• 2016

As the FTAs' implementations are accelerated, an Ex-post assessment, such as an analysis of the tariff schedule and agricultural trade has been emerging as an important national issue for an agricultural sector Korea-EU FTA, which was to be implemented in the five years from July 2016 as one of the giant FTA. The purpose of this study was to determine the demand of an ex-post assessment on agricultural sector as a trade negotiation procedural law. In addition, by providing policy direction for the agricultural policy part requiring amendments and supplements through ex-post assessment, the conflicting arguments between agricultural and non-agricultural sector can be evaluated more objectively. The current evaluation method on the economic impact ex-post assessment of a FTA is generally compared using the change in trade balance before and after the time of FTA implementation. On the other hand, this comparison cannot be said to be the pure FTA effects and objective, tightening economic impact assessment of the FTA in all combined situations, such as the effects of exchange rates and international macroeconomic changes and climate change & occurrence of pests. Over the last 4 years, however, Korea-EU FTA's total accumulated agricultural GDP loss was measured to be 2,178 billion by these research attempts with dynamic analysis as ex-post assessment methodology. The greatest impact was mainly livestock and pork followed by cereals and vegetables. In addition, this research is expected to contribute to policy evaluations in the future.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.4
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• pp.597-605
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• 2006

It is introduced that pit and fissure sealant is the most universal and effective to prevent occlusal dental caries. In processing of being applied the pit and fissure sealant, the various kinds of methods are developed to remove organic matters, plaque, microflora and debris in the pit and fissure for increasing the rates of maintain the sealant. Recently, the Er:YAG laser has been used as a new enamel surface treatment method. The purpose of this thesis is compared whether that enamel surface treatment method is superior to other methods or not. 1. 100mJ 5Hz Er:YAG lased enamel surface was similar to acid-etched enamel in SEM evaluation. 2, Mechanical preparation showed decreased microleakage when compared with acid-etching only, but no significant differences in both method. 3. After laser and acid-etching method showed decreased microleakage when compared with acid-etching only.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.2
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• pp.121-127
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• 1993

The barley plant for whole crop forage is advantageous to have traits with higher photosynthetic rate, biomass, lodging resistance, and awnless spikes. The objective of this study is to investigate performance of near-isogenic line pairs for the awned and awnless in the field, and to observe the variations in photosynthetic rate, yield and their related traits under removal of flag leaf and awns. Grain yield was 6% higher, but biomass and photosynthetic rate were 6～16% and 6% lower in the awned line than those in the awnless grown in the field ,respectively. Defoliation of flag leaf resulted in approximately 3～4%, and 5～6% decreases in 1,000 kernels and grain weights, respectively. Deawning at the heading stage of the long awned line decreased 1,000 kernels and grain weights by 7% and 15%, respectively, The removal of both assimilative tissues caused 14 and 21% decrements in 1,000 kernels and grain weights. Apparent photosynthetic rate of leaf blade in awnless line was 6.1 -9. 7 $CO_2$$_2$ ${\mu}$mole $m^{-2}$ $s{-1}$, much higher than that in awned line. The relative rates in the second and third leaves were about 93% and 55～63%, respectively as compared with that in the flag leaf. The results of the experiments suggest that the awnless line selected for whole crop forage is a potential plant type with higher photosynthetic rate, leaf area and greater biomass.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.115-121
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• 1992

Avermectin B1(abamectin) is an very effective acaricide/insecticide. Because it is applied at low rates, the resultant residue level would be quite low and this requires highly sensitive analytical method. In this study, three analytical methods for avermectin $B1_a$, were compared in view of detectability and sensitivity. The first analytical method was an HPLC method employing the fluorescence detection of avermectin. The second analytical technique to quantitate avermectin $B1_a$, and its photodegradative delta 8,9-isomer employed trifluoroacetic anhydride and 1-methylimidazole in DMF. The new method was the modification of trifluorescence method. The average recoveries of avermectin $B1_a$ for the concentration range from 1 and 10 ng/g in whole apple fruit by fluorescence method were 90.3% and 88.2% respectively. In trifluorescence method, the recoveries of the avermectin $B1_a$ and delta 8,9-isomer were 100.7% and 94.7% in concentration from 5 ng/g and 25 ng/g. The average recoveries of 5 ng and 25 ng/g in the newly modified method were 95.0, 99.0. 96.0, 92.8% in whole apple and soil respectively.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.490-494
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• 2011

Rice stripe virus (RSV) has been the main viral disease of rice plant in western coastal region of Korea since 2000. The control of the vector insect, small brown planthopper (Laodelphax striatellus), is the most effective management method of the persistently-transmitted viral disease. Thus, ecological study between RSV and the vector insect was needed and investigated in order to make effective control plan, especially about study on the feeding and transmission of the virus by the vector insect. Each larval stage of vector insect differed in vector competence; larvae over 4th stage were shown as higher transmission after feeding on RSV-infected rice plant. These 4th and 5th larvae had higher transmission rates, 69.2% and 67.9% respectively, than 44.8% of the adult stage. The vector competence, however, was changed according to temperature; the highest transmission rate was 93.3% on $30^{\circ}C$ in comparison to 70.6% on $25^{\circ}C$ and 43.8% on $20^{\circ}C$.

• Korean journal of applied entomology
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• v.41 no.1
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• pp.55-60
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• 2002

Predation amount and density suppression ability of three species of phytoseiid mites (one native, Amblyseius womersleys Schica; two introduced species, Amblyseius fallacis Garman and Typhlodromus occidentalis Nesbit) on Panonychus citri McGregor were examined in laboratory condition (25$\pm$1$\^{C}$, RH 65$\pm$5%, 16L:8D). A. fallacis and T. occidentalis consumed 20.1 and 9.1 eggs of P. citri, respectively, whereas A. womersleyi consumed 1.1 eggs. When each larva, protonymph and deutonymph of P. citri were supplied as prey for 24 hours. A. womersleyi consumed 23.8, 16.5 and 9.0, and A. fallacis consumed 26.1, 18.2 and 7.4, respectively. However, T. occidentalis consumed only 7.8, 4.2 and 4.2. respectively Density suppression ability of A. womersleyi and A. fallacis against P. citri was very high at the release ratios of 20 : 1 (prey : predator). However, T. occidentalis did not regulate P. citri population effectively Developmental periods from egg to adult of A. womersleyi and A. fallacis was 6.1 and 5.9 days at 25$\^{C}$, respectively.