• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.3
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• pp.233-242
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• 2019

Species composition and yearly variation of fish eggs and larval fishes were investigated from 2014 to 2016. During the study period, the fish eggs were identified as belonging to 14 taxa. The dominant species of fish eggs were Leiognathus nuchalis, Engraulis japonicus, and Konosirus punctatus. These three species accounted for 97.4% of the total number of individuals collected. The collected larval fishes were identified into 37 taxa, 22 families, and seven orders. The dominant species of larval fish were Leiognathus nuchalis, and Gobiidae fishes. These three species accounted for 85.4% of the total number of individuals collected. The diversity index of the larval fishes was the highest in 2014 (H' = 1.60) and the lowest in 2015 (H' = 1.15). The evenness index was the highest in 2016 (J = 0.51) and the lowest in 2015 (J = 0.39). The dominance index was the highest in 2015 (D = 83.5%) and the lowest in 2016 (D = 70.9%). In addition, the economically important species in this area were Engraulis japonicus, Konosirus punctatus, Hippocampus coronatus, Sebastes schlegelii, Acanthopagrus schlegeli, and Cynoglossus joyneri.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.27-32
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• 2005

The recovery of vegetation in the burned area after forest fire was investigated in Mt. Sirubng, Jinju city, from 1994 to 2000. The floristic composition of a burned area was 37 kinds in 2000. The life from spectra of six sites showed H-D1-R5-e type. This type is similar to the life form which has been usually showed in most of burned areas. Total diversity index of six burned sites showed 2.135 (1996), 3.784 (1998), and 2.948 (2000). whereas, total diversity index of six unburned sites was 2.642 (1996), 2.516 (1998), and 2.723 (2000). Evenness index of six sites showed 1.816 (1996), 2.641 (1998), and 1.925 (2000). The dominant index of burned and unburned areas were 0.012 and 0.250 (1996), 0.031 and 0.261 (1998, and 0.110 and 0.275 (2000), respectively. The degree of succession in the unburned area gradually increased and the burned area was recovered to be similar to the unburned area after three years.

• Membrane Journal
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• v.14 no.1
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• pp.26-36
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• 2004

Ultrafiltration membranes based on anion charged poly(bis[4-(3-aminophenoxy)phenyl]sulfone pyromellite) imide derivatives (ACPI) were prepared by the phase inversion method. The polymers have good solubility in aprotic polar solvents. The composition of casting solution and the casting conditions played an important role in determining the permeation characteristics of membrane because the membrane structure could be controlled by the preparation conditions. The extent of fouling-repression was observed by the relative ratio of permeate flux ($J_t$)/pure water flux ($J_0$) and the membrane filtration index (MFI). The characteristics were measured by aqueous solution of bovine serum albumin (BSA) over a pH range of 2.5-9.0. The ACPI membrane having a hydrophilic property was less fouled than the membrane prepared from the original polyimide. With increasing the ion exchange capacity of ACPI membrane, th $\varepsilon$ relative ratio of flux was higher while the membrane filtration index was lower as compared with the original polyimide membrane. From the further away from isoelectric point of bovin serum albumin, the permeation was higher as well as the formation of fouling was more diminish. ACPI membranes having various their properties could be obtained. Further, it was proved that their permeation properties could be determined from the preparation conditions, various operating conditions, and dim $\varepsilon$ rent ion exchange capacity of anion charged polyimide derivatives.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.2
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• pp.40-52
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• 1992

$PbTi0_3$ thin films were deposited at $550^{\circ}C$ by MOCVD method using titanium-iso-propoxide [$Ti(OC_3H_7)_4$] and tetra-ethyl-lead $[Pb(C_2H_5)_4]$as starting materials. In the present study, Ar and $O_2$were used as a carrier gas and a reaction gas, respectively, and the change of thickness and refractive index, Xray diffraction analysis, and CV characteristic measurements of the films were systematically investigated. As a result of CV characteristic analysis of the annealed $PbTiO_3$ thin films, it is assumed that the films interact with Si substrate at the interface, and X-ray diffraction patterns of the films show characteristic peaks for $PbTiO_3$ With increasing the annealing temperature and time, the thickness of the films tends to decrease but their refractive index increases.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.583-592
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• 2001

This study was undertaken to evaluate the clinical effect of inhibiting plaque formation of Lactococcus lactis 1370, a acid producing bacterium residing in the mouth. 30 children were asked to use 10ml of control mouth-wash and mouthwash containing Lactococcus lactis 1370. The plaque index and plaque area rate at 24h and 48h after the use of the mouthwashes were measured. And the number of Lactococcus lactis 1370 was counted at 1h, 3h, and 6h in the mouth. The results are as follow. 1. The mean plaque index at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.43 and 2.06, respectively. The inhibiting rate of plaque formation was 15% (P<0.05). 2. The mean plaque index at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 2.95 and 2.17, respectively. The inhibiting rate of plaque formation was 26%, showing more decrease than at 24h(P<0.05). 3. The mean plaque area rate at 24h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 21.2% and 15.6%, respectively. The inhibiting rate of plaque formation was 26% (P<0.05). 4. The mean plaque area rate at 48h after the use of the control mouthwash and the mouthwash containing Lactococcus lactis 1370 were 33.0% and 17.8%, respectively. The inhibiting rate of plaque formation was 46% (P<0.05). 5. The number of Lactococcus lactis 1370 in the mouth decreased significantly from mouthwashing to 3h, but increased slightly between 3h and 6h. As seen with the above results, we think that using the mouth wash with Lactococcus lactis 1370 would prevent the formation of plaque in the mouth and can be an effective method to prevent dental caries and periodontal disease.

• Journal of Environmental Health Sciences
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• v.29 no.2
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• pp.1-6
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• 2003

This paper reports on a pilot scale comparison of PACS coagulation with and without pH preadjustment. The pH of the water was adjusted with carbon dioxide and sulfuric acid. Process performance was assessed on the basis of total organic carbon(TOC), UV absorbance, turbidity and disinfection by-product(DBP) precursors. Coagulation pH appeared to be a determining factor for maximum NOM removal. The optimum coagulation pH in order to decrease TOC and turbidity were pH 7. Preadjustment of pH 7 increased TOC removal to as much as 43, 47 percent with sulfuric acid and carbon dioxide. Moreover, coagulation at pH 7 caused a reduction in UV$_{254}$, THMFP and HAAFP compared to the baseline coagulation. For preadjustment of pH 7 with carbon dioxide, the percentage of TOC, UV$_{254}$, THMFP and HAAFP shows the reduction rate of 3.8, 0.5, 4.8, 9.4％ comparing to the coagulation rendition using sulfuric acid. Acid addition to depress pH during coagulation decrease Langelier Saturation Index(LSI), potentially causing increase corrosion in water distribution systems. LSI for carbon dioxide and sulfuric acid at pH 6 was -2.3, -3.3. Therefore, carbon dioxide was more effective at controlling corrosion than sulfuric acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.263-269
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• 2017

The mineral contents, and free amino acid, and fatty acid composition of rack and bag or suspended cultured oysters Crassostrea gigas were compared. The moisture content did not change much from 82.8% to 86.3% in the different culture methods. The glycogen level was low 4.7% during rack and bag culture but high 7.2% during suspended culture. The sodium level was the highest during suspended culture, while copper and zinc level were highest during rack and bag culture. The taurine level was 1,385-1,375 mg/100 g in oyster cultured using the rack and bag method, but that in the market sample was lowest at 1,015.8 mg/100 g. Hydroxyproline, glutamic acid, proline, glycine, and alanine were detected at high levels in the experimental oysters. The polyunsaturated fatty acid content was similar among samples. The docosahexaenoic acid level was 14% with rack and bag culture and 12% with suspended culture, whereas the eicosapentaenoic acid level was 15% with rack and bag culture and 20% with suspended culture. The atherogenic index (AI), thrombogenicity index (TI), and hypocholesterolemic/ hypercholesterolemic (h/H) ratio were important factors in the nutritional evaluation. The AI and TI values were 0.5-0.2, and the h/H ratio were 2.0 and 2.4 with the rack and bag and suspended culture, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.4
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• pp.56-63
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• 2010

Microcrystalline cellulose (MCC) was prepared from Miscanthus in this study. Two pulping methods, soda pulping and alkaline sulfite pulping were applied as a pretreatment process. After pulping, two different bleaching processes such as $ClO_2$ treatment followed by $H_2O_2$ treatment and $O_3$ treatment followed by $H_2O_2$ treatment were carried out. Two concentration of $H_2SO_4$, 47% and 57% were applied to the purified Miscanthus cellulose as a acid hydrolysis process to make MCC. The crystallinity index and morphological properties of the produced MCC were evaluated with X-ray diffractometer and scanning electron microscopy. The MCC originated from the soda pulping sample showed the higher crystallinity index than that originated from the alkaline sulfite pulping sample. The two stages of treatmen twith $O_3$ and $H_2O_2$ resulted in the higher purified cellulose products.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.1
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• pp.34-48
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• 1993

This experiment were conducted to investigate heterosis and combining ability for several mutant characters by analyzing dialled crosses of flue-cured tobacco. In a dialled cross of 3 flue-cured varieties and the mutant line 83H -5, the heterosis was somewhat higher in Fl than in F2. For growth character, the heterosis was 0.28-6.03% in plant height, leaf number, leaf shape index and yield, and was 43.2% for bacterial wilt disease index. The mutant line 83H-5 showed significantly negative GCA effect for plant height, leaf width and bacterial wilt disease index in Fl and F2, leaf length in F2, and positive GCA effect for total alkaloids, total nitrogen in Fl and days to flower in F2, respectively. Specific combining ability(SCA) in 83H-5 x Hicks was significant in negative effect for leaf length(F2), number of leaves(F2), leaf shape(F1, F2), bacterial wilt(F2) and alkaloids(F1), and in 83H-5 x NC 2326 in positive effect for leaf length(F1, F2) and leaf width(F2), and for 83H-5 x NC 82 in positive effect for plant height(F1, F2) and leaf width(F2), and for 83H-5 x NC 82 in Positive effect for Plant height(F1, F2), leaf length(F2) and yield(F1, F2).

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.3
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• pp.274-284
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• 2003

Multi-level converter that is high-capacity electric power conversion system is used widely to electric motor drive system and FATCs(Flexible AC Transmission Systems). H-Bridge converter has been prevalently applied to shunt-type system because it can be easily expanded to the multi-level. In steady states, converter is normally operated in the range of 0.7∼0.8 of modulation Index. Even though zero vectors are not imposed to high modulation index, DC-Link voltage Is constant. It means that converter has another boost vector except for zero vectors among several vectors in 3-level converter. This paper has examined the principle of boost vector and investigated the difference between another boost vector and zero vectors in 3-level converter. In addition, this paper has analysed and compared the charging currents and the capacitor voltages of two topologies. The currents and voltages are related to reference voltage. Therefore, it proposed the calculation method for the voltage ripple and the charging current of each capacitor and compared various DC-Link voltage control methods through the simulation.