• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.4
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• pp.233-250
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• 1970

The present paper deals with the results of the observations on the characteristics of the eggs being ripen by injection of synahorin and the larvae of the black porgy. Mylio macrocehalus (Basilewsky). The adult fish used in the experiments, during May 11th to June 5th, 1970, were obtained from a fish-farm of the Atsumi Fish Culture Company in Aichi Prefecture, Japan, The results obtained are as follows: 1. The egg is colorless and buoyant, spherical in shape, measuring from $0.81\~0.96\;mm$ in dia-meter with a single oil globule, measuring $0.20\~0.23\;mm$. 2. Hatching took place within about 35 hours and 50 minutes after insemination of eggs at the water temperature $19.6\~22.5^{\circ}C$ (Mean, $20.6^{\circ}$). 3. The newly hatched larvae were 1.57 mm in total length, with the oil globule situated at the posterior part of the elongated oval-shaped yolk sac. Melanophores and xanthophores were distributed on the middle of the caudal region, and were scattered on the surface of the oil globule, but none on the yolk sac. 4. The diameter of the eggs ill each adult is distinguished into two types, large and small. The former is in the range of $0.811\~0.873\;mm$, the latter is $0.874\~0.963\;mm$. 3. The hatching rate of black porgy was in the range of $78.63\~95.19\%$ in large and $68.84\~74.80\%$ in small eggs. The mean hatching rate of total eggs was $79.80\%$. 6. The optimum temperature of hatching black porgy is in the range of $20\~26^{\circ}C$. The highest temperature limit of hatching the black porgy is from $26.71\~28.56^{\circ}C$. 7. The total length of hatched larvae is not maintained pararell to diameter of eggs and total length of the large larvae is from $1.976\~2.225mm$, and that of small larvae is $1.526\~1.90mm$. 8. The diameter of yolk sac of black porgy is in the range of $0.878\~0.979\;mm$ 9. The initial survived larva of the black porgy was $13.71\%$ in minimum, and $79\%$ in maximam. And the mean initial survived rate was $48.3\%$. 10. In conclusion, the biological characteristics of hatched larva of black porgy is seemed to be possible for large scale production of artificial seedlings. But experimental results make initial food the prime object believed to be supplemented.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.762-767
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• 2009

In this study, the feasibility of using vegetable oil extracted from tropical crop seed as a biodiesel feedstock was investigated by producing biodiesel and analysing the quality parameters as a transport fuel. In order to produce biodiesel efficiently, two step reaction process(pre-treatment and transesterificaion) was required because the tropical crop oil have a high content of free fatty acids. To determine the suitable acid catalyst for the pre-esterification, three kinds of acid catalysts were tested and sulfuric acid was identified as the best catalyst. After constructing the experimental matrix based on RSM and analysing the statistical data, the optimal pre-treatment conditions were determined to be 26.7% of methanol and 0.982% of sulfuric acid. Trans-esterification experiments of the pre-esterified oil based on RSM were carried out, then discovered 1.24% of KOH catalyst and 22.76% of methanol as the optimal trans-esterification conditions. However, the quantity of KOH was higher than the previously established KOH concentration of our team. So, we carried out supplemental experiment to determine the quantity of catalyst and methanol. As a result, the optimal transesterification conditions were determined to be 0.8% of KOH and 16.13% of methanol. After trans-esterification of tropical crop oil, the produced biodiesel could meet the major quality standard specifications; 100.8% of FAME, 0.45 mgKOH/g of acid value, 0.00% of water, 0.04% of total glycerol, $4.041mm^2/s$ of kinematic viscosity(at $40^{\circ}C$).

• The Korean Journal of Mycology
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• v.17 no.1
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• pp.1-6
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• 1989

The mycelia of Pyricularia oryzae were treated with enzyme solution mixture consisting of Driselase, ${\beta}-Glucuronidase$, Cellulase, and Macerozyme R-10 for the production of protoplasts. More protoplasts were formed from mycelia of race KJ 101 of P. oryzae than that of race KI 315a in the enzyme mixtures. The number of protoplasts was decreased in the untreated control three hrs after the enzyme treatment, whereas the number was increased in the treatments with 10, 50 and 100 mM 2-mercaptoethanol, respectively. The number of protoplasts increased to reach maximum at five hrs after treatment of 10 mM 2-mercaptoethanol, but the least was found in 200 mM. The protoplasts of P. oryzae in a liquid medium containing 2.5% yeast extract, and 2% dextrose reverted to the mycelia after five hrs shaking incubation at $27^{\circ}C$. Some protoplasts produced yeast like buds and the buds were developed to irregularly shaped chains of cell protruded a germ tube like hypha from the distal cell. Once in a while a germ tube like hypha protruded directly from the protoplasts. Except in the first type of reversion, other protoplasts reverted to the normal mycelia. The reversion frequency was highest on PDA with stabilizer of 0.6 M KCl. No reversion of protoplasts occurred on water agar regaardless oftreaatments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.687-697
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• 2019

By monitoring sediment grain size and level variation of tidal flat surface for 6 years (2005-2011), and also by mooring TISDOS (tidal-flat sediment dynamics observation system) on the low intertidal flat in 2008, we investigated the sedimentary environment of tidal flat in the dammed Yeongsan River Estuary. The tidal flat of the Yeongsan River Estuary lost 82 % of its area because of coastal development projects, and a narrow tidal flat below mean sea level now remains. Most of the tidal flat sediments are composed of silt up to 70-94 %, and show the characteristics of clay deficiency and silt dominance. This is closely related with the coastal development, which led to the destruction of high tidal flats where most mud settled, and the modification of tidal current patterns. Moreover, the estuarine tidal-flat sediments reveal seasonal variation. They are coarse with abundant silt during windy autumn to spring, fine with abundant clay during the less-windy and high-discharge summer. This phenomenon indicates that the behavior of sediment particles on the low intertidal flats of the Yeongsan River Estuary is influenced by wind waves for silt and fresh water discharge and the tidal process for clay. Monitoring results of the altitude of tidal flat surface showed that the study area had eroded at an average rate of -2.6 cm/y during the period of 2005-2011, and also that an unusual deposition with a rate of 4 cm/y occurred in 2010. The erosion can be explained by an increased tidal amplitude and a strengthened ebb-dominant tidal asymmetry after the construction of an estuary dike and the Yeongam Kumho Seawall. The deposition in 2010 seems to have been closely related to the mass production of suspended materials from dredging of the estuary.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.52-60
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• 2016

The biological activity of polysaccharide is greatly influenced by polysaccharide structure and molecular distribution. Here, we developed a rapid and convenient isolation method for fractionating polysaccharides with different characteristics and optimized it using a polysaccharide mixture from Korean persimmon leaves. A crude polysaccharide mixture, persimmon leaves-enzyme (PLE) fraction, was isolated from persimmon leaves digested with pectinase and ethanol precipitation. The PLE fraction was further fractionated with a serially diluted ethanol solution (ethanol : deionized water=4:1, 2:1, 1.5:1, 1:1, and 0.5:1) to produce 10 subfractions (five precipitate fractions labeled from PLE-4 to PLE-0.5 and five supernatant fractions labeled from PLE-4S to PLE-0.5S). HPLC analysis indicated that PLE-4 and -2 consisted of diverse polysaccharides, whereas PLE-1.5, -1, and -0.5 contained high molecular weight (MW) polysaccharides. The fractions from PLE-4 to PLE-1 were mostly composed of 13 different characteristic sugars in rhamnogalacturonan (RG) I and II, and the sugars contained an arabino-${\beta}$-3,6-galactan moiety. However, PLE-0.5 did not contain RG-II or ${\beta}$-arabino-3,6-galactan. Treatment of macrophages with fractions PLE-1.5S and PLE-1S led to a $10{\mu}g/mL$ increase in interleukin (IL)-6 production, whereas treatment with PLE-4S and PLE-2S fractions composed of low MW polysaccharides resulted in reduced levels of IL-6. These results indicate that this isolation method may be useful for the rapid and convenient fractionation of bioactive RGs from polysaccharide mixtures with various properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1017-1024
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• 2011

Korean wheat semolina (FS: fine semolina) with similar characteristics to durum wheat semolina was substituted at rates of 0, 10, 20, 30, 40, and 50% in pasta dough and the physical and cooking characteristics were investigated for making optimal pasta. Water absorption of the dough increased with the 10, 20, and 30% substitution ratio of FS. Development times were high with >30% substituted FS. This result positively influenced an increase in production and the preparation of the fresh noodle pasta. Furthermore, soft textured fresh noodles could be made due to the decrease in stability and increased weakness of the >30% substituted FS. The amylograph gelatinization characteristics of Korean wheat semolina exhibited an increase of gelatinization temperature and decrease of maximum viscosity when compared with durum wheat. The handling property of the dough showed more than 4 points in all sample groups. Weight and volume decreased and turbidity and cooking loss increased according to the increasing amount of substituted FS. However, samples with ${\leq}$ 30% FS substitution ratio had similar volumes and cooking losses when compared to the control. The L- and a-values increased and the b-value of color decreased as more FS was added. In a texture analysis, the hardness of the cooking noodles showed a low value with the >30% substituted FS. Springiness, gumminess, and chewiness exhibited a high value. In the results of a sensory evaluation, overall acceptability was high score with more than 7 points for the 30% added FS. The preferences for pasta colors were divided into white, which is similar to the Korean traditional noodle, and yellow, which is similar to durum wheat. Flavor and taste were not affected by substituting with FS. Low hardness and high chewiness was the most preferred noodle. These results suggest that >30% substituted FS was suitable for increasing quality and organoleptic qualities of Korean wheat pasta.

• Korean Chemical Engineering Research
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• v.55 no.3
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• pp.385-394
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• 2017

In this study, reaction mechanism and curing characteristics of adhesives formulated with NaOH- and $H_2SO_4$-hydrolyzed chicken feather (CF) and formaldehyde-based crosslinkers were investigated by FT-IR and DSC. In addition, adhesive properties and formaldehyde emission of medium-density fiberboards (MDF) applied with the adhesives were measured. CF-based adhesives having a solid content of 40% and over were very viscous at $25^{\circ}C$, but the viscosity reduced to $300{\sim}660m{\cdot}Pa{\cdot}s$ at $50^{\circ}C$. Consequently, the adhesives could be used as a sprayable resin. Through the FT-IR spectra of liquid and cured CF-based adhesives, addition reaction of methylol group and condensation reaction between the functional groups with the use of formaldehyde-based crosslinkers were identified. From the analysis of DSC, it was elucidated for CF-based adhesives to require a higher pressing temperature or longer pressing time comparing to commercial urea-formaldehyde (C-UF) resin. MDF bonded with CF-based adhesives, which was formulated with 5% NaOH-hydrolyzed CF (CF-AK-5%) and PF of formaldehyde to phenol mole ratio of 2.5 (PF-2.5), and pressed for 8 min had higher MOR and IB than those with other CF-based adhesives. MOR and IB of MDF bonded with the CF-based adhesives regardless of formulation type and pressing time were higher than those with C-UF resin. When the values compared with the minimum requirements of KS standard, IB exceeded the KS standard in all formulations and pressing time, but MOR of only MDF bonded with CF-AK-5% and PF-2.5 and pressed for 8 min satisfied the KS standard. What was worse, 24-TS of MDF bonded with all CF-based adhesives did not satisfied the KS standard. However, MOR and 24-TS can be improved by increasing the target density of MDF or the amount of wax emulsion, which is added to improve the water resistance of MDF. Importantly, the use of CF-based adhesives decreased greatly the formaldehyde emission. Based on the results, we reached the conclusion that CF-based adhesives formulated under proper conditions had a potential as a sprayable resin for the production of wood panels.

• Journal of Bio-Environment Control
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• v.26 no.1
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• pp.43-48
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• 2017

This experiment was conducted to test the suitability of various organic materials in order to reduce the use dependence of peatmoss as a soil pH regulator and to examine the effect of soil organic matter supply. A 2-year old northern-highbush blueberry (Vaccinium corymbosum L.) 'Duke' plants were planted in the field at $2.0m{\times}2.5m$ spacing in spring. Before planting, organic materials were incorporated into the soil including the planting hole at 20 liter per plant, as the following mixtures: peatmoss only (20 L), peatmoss (10 L) + pine needle (10 L, PN), peatmoss (10 L) + rice hull (10 L, RH), and peatmoss (10 L) + sawdust (10 L, SD). The pH of organic materials was lowest in peatmoss (pH 4.3), followed by PN (pH 4.8), SD (pH 5.7) and RH (pH 7.8). Soil pH measured right after planting ranged from 5.3 to 5.9 and was lower in PM only and PM + PN than PM + RH and SD treatments. In the third year, the pH lowered to the range of 4.2 to 4.5, with PM and PM + PN still maintaining lower values. The early growth was good in the mixed treatment of PM and PN, and the plant height and width and the number of new shoots were good in the PM treatment. Soil water content was maintained highest in PM + PN, followed by PM, PM + SD and PM + RH. Vegetative growth was maintained better in PM and PM + PN, and the number of flower cluster and yield were also slightly higher in those treatments while mean fruit weight was similar among all treatments. Fruit quality indices such as total soluble solids, titratable acidity and firmness were not affected.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.4
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• pp.71-102
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• 2007

There were many comprehensive analyses conducted within the existing research activities wherein factors affecting technology progress including investment in R&D vis-${\Box}$-vis their influences act as the determinants of TFP. Note, however, that there were few comprehensive analysis in the industrial research performed regarding the impact of the economy of scale as it affects TFP; most of these research studies dealt with the analysis of the non -parametric Malmquist productivity index or used the stochastic frontier production function models. No comprehensive analysis on the impacts of individual independent variables affecting TFP was performed. Therefore, this study obtained the TFP increase rate of each industry by analyzing the factors of the existing growth accounting equation and comprehensively analyzed the TFP determinants by constructing a comprehensive analysis model considering the investment in R&D and economy of scale (smallness by industry) as the influencers of TFP by industry. First, for the TFP increase rate of the 15 industries as a whole, the annual average increase rate for 1993${\sim}$ 1997 was approximately 3.8% only; during 1999${\sim}$ 2000 following the foreign exchange crisis, however, the annual increase rate rose to approximately 7.8%. By industry, the annual average increase rate of TFP between 1993 and 2000 stood at 11.6%, the highest in the electrical and electronic equipment manufacturing business and IT manufacturing sector. In contrast, a -0.4% increase rate was recorded in the furniture and other product manufacturing sectors. In the case of the service industry, the TFP increase rate was 7.3% in the transportation, warehousing, and communication sectors. This is much higher than the 2.9% posted in the electricity, water, and gas sectors and -3.7% recorded in the wholesale, food, and hotel businesses. The results of the comprehensive analysis conducted on the determinants of TFP showed that the correlations between R&D and TFP in general were positive (+) correlations whose significance has yet to be validated; in the model where the self-employed and unpaid family workers were used as proxy variables indicating the smallness of industry out of the total number of workers, however, significant negative (-) correlations were noted. On the other hand, the estimation factors of variables surrogating the smallness of scale in each industry showed that a consistently high "smallness of scale" in an industry means a decrease in the increase rate of TFP in the same industry.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.231-236
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• 2007

A feeding trial was conducted to study the effects of dietary supplement of fermented clay mineral (FCM) on the growth performance and immune stimulation in broiler chickens. A total of 36,800 broilers, (of) Ross strain-208, were randomly allotted into 2 experimental (diet) groups. Control group was fed the basal diet (corn-soybean meal based), and treatment group was fed the natural clay mineral that was fermented with aboriginal microorganisms at $37^{\circ}C$ for 72 h. Feed and water were provided ad libitum throughout the experiment for 5 weeks of experimental feeding period. Daily weight gain of treatment group fed 0.3% fermented clay mineral was significantly increased in comparison with control group. Feed intake of treatment group was significantly increased 21.4% (p<0.05), and feed efficiency was also increased 2.7% compared to control group. Especially, growth rate and production index of treatment group were significantly higher as much as 4.4% and 4.8%, respectively, than those of control group (p<0.05). By the feeding of dietary 0.3 % FCM, the antibody productions against Newcastle Disease and Infectious Bursal Disease antigens were shown to increase 13.8 % and 15.7 %, respectively, more than control group chickens. From these results, it appears that the supply of fermented clay mineral at 0.3 % level in the broiler chicken diet could enhance the growth performance and immune stimulation of broiler chickens.