• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.514-519
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• 2000

In order to develop the method for the calculation of flow resistance acting on cage net, the relation between the velocity reduction factor and $S_n/S$, the ratio of total area of netting projected to the perpendicular to the water flow $S_n$ to wall area of netting S, was derived based on the numerical and experimental analysis of the wake flow through a netting twine simplified by a cylinder and a netting panel. The velocity was reduced in accordance with the velocity reduction factor when the flow passed the netting panel upstream of a cage net. The proposed method for the calculation of fluid force acting on a square cage net was based upon the assumption that it could be divided into four side panels and one bottom panel. It was proved that the force could be calculated by the sum of the drag forces acting on the individual netting panels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.405-411
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• 1994

This study was carried out to determined the optimum seeding rate and number of seedling stands per unit area for high yield with two varieties of rice, Nakdongbyeo (Japonica type) and Samgangbyeo (Indica x Japonica type), in direct water-seeded rice culture at Crop Experiment Station. Seeds coated with $CaO_2$ after germination were sowed at May 4 in 7 levels, such as 1.6, 1.8, 2.1, 2.7, 3.5, 4.0, 4.3kg /10a, and the number of seedling stands per square meter was adjusted to be 30, 40, 60, 80, 100, 120, 140 plants, respectively. The maximum number of tillers increased as the seeding rates increased, but the ratio of effective tillers decreased. The critical dates of effective tillering of tested varieties were delayed by the lower seeding rates, and the date was June 18 at the plot of seeding rate with 3.5kg /10a. The number of panicles per unit area increased in accordance with the increased seeding rates. The number of spikelets per panicle in Nakdongbyeo was not affected by the seeding rates, but in Samgangbyeo it decreased as the seeding rate increased. The optimum number of seedling stand per square meter appeared to be 78 in Nakdongbyeo and 120 in Samgangbyeo, respectively. It meant that the optimum seeding rates for Nakdongbyeo and Samgangbyeo were about 2.7 and 4.0kg /10a, respectively.

• The Korean Journal of Nuclear Medicine
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• v.9 no.1
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• pp.51-58
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• 1975

It is a great value to find an early detection of involvement of ureteric obstruction in the carcinoma of cervix. Little or no knowledge of the condition of the kidneys or the lower urinary tract are able to elucidate by the biochemical studies such as blood nitrogen or urine creatinine in carcinoma of cervix. Findings of urography delineates the condition of urinary tract stasis in the renal pelvis and ureters, however, slight stasis maybe difficult to demonstrate. On the other hand isotope nephrography is accepted as a sensitive method to observe renal function especially in regarding to the excretory function of kidney. It was attempted to analysis the findings of urography conjunction with isotope nephrography in 50 cases of unselected patients with invasive carcinoma of cervix through pre and post irradiation follow up studies. Urography was done as a routine procedure and.analysed emphasising changes of collecting systems and ureter condition. Isotope nephrography was carried out by means of $15{\mu}ci\;I^{131}$-Hippuran injected intravenously and the curves were analysed as follows. Parameter were; time of maximum amplitude ($T_{max}$), half time of maximum amplitude ($T\frac{1}{2}$), Kac and Kex value calculated from these two parameters in Tobe's method. The excretion index by Aurell defines the ratio between the maximum activity and the activity measured on the slope of the third phase ten minites after it has reached its maximum. Results: 1. 28.8% had an abnormal IVP suggestive of ureteric involvement before irradiation therapy and the patient of stage III and IV were the great part. 2. 21.7% had abnormal findings of per-irradiation renogram whom showed normal IVP. The other group showed normal IVP which group also showed normal renogram prior irradiation. 3. The more severe the ureteric involvement, the change of excretion index was greater. 4. Even in stage I and II patient, abnormal renogram was revealed in 12 cases (39.4%) among 31 cases. 5. All cases of TAH showed abnormal findings of IVP and renogram. 6. No. definite change of renogram was obtained just after the irradiation therapy (point $A:8000{\sim}9000rads,\;B:5000{\sim}6000rads,\;Co:11000{\sim}13000rads$). Each 3 month follow up study was performed and comparing with preirradiation study which showed significant changes of excretion index of renogram were 42.8% in $6{\sim}9$ month follow-up and 75% in $9{\sim}12$ month, respectively. 7. It seems to be important to observe the parameter Kex and excretion index of renogram to determine early abnormality of kidney excretory function by means of post-irradiation follow up study.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.1-6
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• 2005

With recent interest organic farming the use of legumes including vetch and clover to provide N to adjacent crops is increasing in Korea. In the present studies, we conducted a trial to investigate the effects of the application of N rate on nitrogen fixation and transfer from vetch to barley in mixed stands. The experiment was arranged in a randomized complete block design with three replications. Four different N rates(0, 75, 113 and 150/ha) was used and vetch+barley was broadcasted manually on 1.5 $\times$2 m plot in Oct. 2001. Half of urea and K$_{2}O, 200 Phosphate and 75 kg potash per ha were applied as basal dressing md half of N md 75 potash were used for topdressing to soil surface on MarctL 2002. The equivalent of 1kg ha$^{-1}$ at($^{15}$NH$_{4}$)$_{2}$SO$_{4}$ solution at 99.8 atom $\%$$^{15}$N excess was applied to the microplot in mid April. Forage was harvested from each plot at ground level and separated into barley and vetch. Total N content and It values of samples were determined using a continuous flow stable isotope ratio mass spectrometry(IsoPrime-EA. Micromass, UK.). The percentage of legume H fixed from atmospheric N2 were 95.0, 93.8, 94.4 and $84.8\%$ with increment of N levels. The percentage of N transfer from vetch to barley by N-difference method with increment of N fertilizer were from 58 to$49\%$ while 39 to $23\%$ in $^{15}$N-dilution method. The amount of transfer from vetch to barley were 87 to 68 kg/ ha with N level by N-difference moth여 and 58 to -56/ha with N application levels by $^{15}$N dilution method. The amount of nitrogen fixation per ha were from 150 kg / ha to 219 kg / ha by different method, but on the other side 49 to 105kg/ha by N$^{15}$-dilution.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.682-688
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• 2014

The in vitro digestibility and molecular and crystalline structures of rice starches (Seilmi, Dasan1, and Segoami) with differing amylose content were investigated. Segoami had the highest amylose content (30.9%), whereas Dasan1 had the lowest amylose content (21.2%). The molecular weight ($\bar{M}_w$) of amylose and amylopectin in Segoami was much lower than that of the other two rice starches. Segoami had the highest proportion (8.7%) of amylopectin short branch chains (DP 6-12) and the lowest proportion of B1 chains (DP 13-24). The relative crystallinity, intensity ratio of $1047-1022cm^{-1}$ (1047/1022) and gelatinization enthalpy followed the order: Segoami>Seilmi~Dasan1. Segoami showed substantially low pasting viscosity. Rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) contents showed the highest value in Seilmi, Dasan1, and Segoami, respectively. The expected glycemic index (eGI) of Segoami was lower than that of the other two rice starches. Overall results suggested that the digestibility of rice starch could be highly influenced by their molecular and crystalline structure.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.251-256
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• 2007

The crystal structure of fully dehydrated partially Cs+-exchanged zeolite X, [Cs52Na40Si100Al92O384], a = 24.9765(10) A, has been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21 °C. The crystal was prepared by flow method for 5 days using exchange solution in which mole ratio of CsOH and CsNO3 was 1 : 1 with total concentration of 0.05 M. The crystal was then dehydrated at 400 °C and 2 × 10-6 Torr for 2 days. The structure was refined to the final error indices, R1 = 0.051 and wR2 (based on F2) = 0.094 with 247 reflections for which Fo > 4σ (Fo). In this structure, about fifty-two Cs+ ions per unit cell are located at six different crystallographic sites with special selectivity; about one Cs+ ion is located at site I, at the centers of double oxygen-rings (D6Rs), two Cs+ ions are located at site I', and six Cs+ ions are found at site II'. This is contrary to common view that Cs+ ions cannot pass sodalite cavities nor D6Rs because six-ring entrances are too small. Ring-opening by the formation of ?OH groups and ring-flexing make Cs+ ions at sites I, I', and II' enter six-oxygen rings. The defects of zeolite frameworks also give enough mobility to Cs+ ions to enter sodalite cavities and D6Rs. Another six Cs+ ions are found at site II, thirty-six are located at site III, and one is located at site III' in the supercage, respectively. Forty Na+ ions per unit cell are located at two different crystallographic sites; about fourteen are located at site I, the centers of D6Rs and twenty-six are also located at site II in the supercage. Cs+ ions and Na+ ions at site II are recessed ca. 0.34(1) A and 1.91(1) A into the supercage, respectively. In this work, the highest exchange level of Cs+ ions per unit cell was achieved in zeolite X by conventional aqueous solution methods and it was also shown that Cs+ ion could pass through the sixoxygen rings.

• Korean Journal of Agricultural Science
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• v.29 no.1
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• pp.66-83
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• 2002

The economic feasibility analysis including benefit-cost ratio and internal rate of return of a land consolidation and on-farm development project was mainly depended upon the direct benefits and costs arising during project life. Therefore the projects were neglected in allocating the government's financial funds and loans on account of the low economic rate of return of the project. Accordingly the extended benefit-cost analysis method should be introduced and adapted to cover not only the benefit s such as non-market values of environmental and food security fun ct ions of the project but also market values of the project outputs. The main purposes of this study are (1) to prepare a guide line for economic feasibility analysis based on the IBRD and ADB guidelines, (2) to estimate the benefits from productivity increase, labor saving, savings of O&M cost of farm mechanization and project facilities, savings of farmer's burden for their public health, increasing environmental and public functional value of paddy fields, improving food security condition and formation of peaceful and uncontroversial rural society by implementing the land consolidation and on-farm development, (3) to introduce the newly adapted analytical method as the extended benefit cost analysis which could make possible to be included the values of non-market goods such as the food security and the environmental public function of paddy fields. To carry out this study, the existing publications on the guidelines for economic agricultural projects were reviewed and consultation was made with a For the post evaluation study of the land consolidation and on-farm development project, field survey in Jigok and other comparative area were made to get available information. According to the project completion report, Jigok land consolidation and on-farm development project has 55ha of benefit area out of 69ha of gross area. The project was started in November 11th, 2000 and completed october 30th, 2001. The total project costs were amounted to 2,548 million won and the annual project benefits were estimated at 335million won evaluated by domestic market prices. The ERR(Economic Rate of Return) and SRR(Social Rate of Return) of the project based on the shadow pricing system were estimated at 4.4% and 16% respectively. On the other hand, the ERR and SRR based on the domestic market value system were amounted to 6.37% and 14.62%. In conclusion, Korean land consolidation and on-farm development projects have not carried out from the view point of economic rate of return under shadow pricing system but from the view point of domestic pricing system. For the future feasibility studies on land consolidation projects have to be carried out including the non-market values as environmental and food security function of the projects.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.200-206
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• 1998

The distributions and characteristics of bacteria on the deodorizing biofilters were studied as a part of biofiltration research for odor gas removal. The odor gas originated from a currently operating nightsoil treatment plant were mainly nitrogenous compounds of ammonia and amines. The filter media were consisted various ratio of pine bark, nightsoil cast and compost, and were sampled before and after operation of 153 days. Before operation, the level of bacteria on nitrification agar medium, nutrient agar medium and thiosulfate agar medium were around $10^7{\sim}10^8cfu/g$ media. After operation, the level decreased but still high as $10^5{\sim}10^7cfu/g$ media. The bacteria from reactors before and after operations were either rod or coccus after growth on nitrification agar media. The 45 isolated heterotrophic bacteria were further characterized and Pseudomonas, Bacillus, Flavobacterium, Alcaligenes were dominant genera. Genus Alcaligenes was particularly dominant when the isolates were incubated on nitrification agar media first and then transfered to nutrient media. The portion of Alcaligenes in the biofilter increased after operation, and was higher in the media contained nightsoil cast, which showed better treatment than the media with pine bark only.

• Tribology and Lubricants
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• v.37 no.6
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• pp.232-239
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• 2021

Petroleum is the most consumed energy source in Korea with a usage rate of 38.7% among the available primary energy sources. The price of liquid petroleum products in Korea includes taxes such as transportation·environment·energy tax. Thus, illegal production and distribution of liquid petroleum is widespread because of its huge price difference from that of the normal product and its tax-free nature. Generally, the illegal petroleum product is produced by mixing liquid petroleum with other similar petroleum alternatives. The two kinds of gasoline, common gasoline and premium gasoline, are being distributed in Korea. The premium gasoline is often adulterated with cheaper common gasoline that lowers the octane number of gasoline. It is possible to distinguish them with their color difference, green and yellow for different grade gasoline. However, when small volume of common gasoline is added to premium gasoline, it is difficult to determine whether premium gasoline contained common grade or not. In this study, we inspect gasoline, which is illegally produced by mixing common gasoline to premium gasoline. When the ratio of mixing common gasoline is increased, premium gasoline shows decreasing absorbance at 600 nm and 650 nm under UV-Vis spectrometer. Moreover, the detected intensity (mV·s) of green dye in high performance liquid chromatography (HPLC) was decreased by common gasoline under 0.99 correlation value. The more the common gasoline is mixed, the more olefin and naphthene are detected by gas chromatography. In addition, trimethyl pentane as octane improver, paraffin and toluene are decreased by common gasoline mixing. The findings of this study suggests that illegal petroleum can be identified by analysis of components and simulated samples.

• The Journal of Natural Sciences
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• v.4
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• pp.103-142
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• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.