• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.254-259
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• 2001

In order to make clear the resistance of plane nettings u,sed widely in constructing net cages, the resistance R taken by $R=kSU^2$, where S was the wall area of nettings, U the flow velocity, and k the resistance coefficient, was measured in a circulating water channel by using nylon Raschel nettings and PE trawler-knotted nettings coated with anti-fouling paint or not and then the properties of coefficient k were investigated. The mesh size L and the angle $\phi$ between two adjacent bars was given by the function of Reynolds number ${\lambda}U/v$ in the region of ${\lambda}U/v<180$, i. e., $$k=350(\frac{\lambda U}{v})^{-0.25}$$.where $\lambda$ was the representative size of nettings expressed as $$\lambda=\frac{{\pi}d^2}{2L\;sin\;2{\phi}}$$On the other hand, the coefficient k was almost fixed between 92 and 102 ($kg{\cdot}s^2/m^4$) in the region of ${\lambda}U/v{\geq}180$ and varied according to the ratio $S_n/S$ of the total area $S_n$ of nettings projected to the plane perpendicular to the water flow to the wall area S of nettings, i.e., it was given by $$k=98.6(\frac{S_n}{S})^{1.19}$$ regardless of the coating of paint.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.115-121
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• 2002

To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.361-367
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• 1984

In previous paper(Lee et al., 1984), preparation formula and processing conditions of the fish meat (mackerel) paste using dielectric heating were described, that included the proper shape and size of product and the conditions of dielectric heating, hot air dehydration, and heating with electric heater to yield the minimum expansion and case hardening during heating and to controll the final rater activity of 0.86 to 0.83 accompanying with a complete reduction of viable cells and good texture. In present study, changes in VBN, pH, total plate count, water activity, texture, the loss of available lysine, color indexes, TBA value, and the content of TI were determined to assess the quality stability and shelf-life of the product during the storage for 35 days at $5^{\circ}C\;and\;25^{\circ}C$, respectively. And the effect of vacuum sealing and hot water treatment before storage on the storage stability of product was also mentioned. As the product was vacuum packed in K-flex film bag, heat treated in boiling water for 6 minutes, and stored, water activity was maintained 0.86 to 0.84 for 35 days regardless of storage temperature, and the increase of total plate count was negligible in case of $5^{\circ}C$ storage while tended to gain slightly after 25 days at $25^{\circ}C$ storage. Changes in VBN was also minimum with an increase of 1.5 mg/100g at $5^{\circ}C$ and 7.0mg/100g at $25^{\circ}C$, but in case of unpacked sample, it was 24.5mg/100g at $5^{\circ}C$ and 42.4 mg/100g at $25^{\circ}C$ even after 7 days. In textural property hardness tended to increase after 28 days and folding test score was down to A or B from AA grade. The loss of available lysine was $7.5\%\;at\;5^{\circ}C$ and $17.0\%\;at\;25^{\circ}C$ but brown color was not deeply developed as the color index score indicated. TBA value was not increased at $5^{\circ}C$ while it tended to increase rapidly after 30 days at $25^{\circ}C$. Changes in TI content was not obvious except that it showed a tendency of increase at the end of storage as well as in the change of lysine and TBA value. It is concluded from the results that the quality of the product, pasteurized and water activity controlled by dielectric heating, and vacuum packed in K-flex film would be stable for more than 35 days at $5^{\circ}C$ and at least 25 days even at room temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.103-108
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• 2008

To develop an optimal composite recipe for a functional abalone porridge including abalone viscera, this study investigated the effects of added viscera on the physical, textural and sensory characteristics of the porridge. Several kinds of abalone porridge were prepared with 1%, 2%, 3%, 4%, or 5% of the viscera (w/w) and with round rice, half rice, or ground rice. pH of the porridge with half and ground rice decreased with increasing amounts of the viscera. TBARS value increased with increasing size of rice and increased with increasing amount of the viscera in the porridge with round and ground rice. Yellowness of the porridge increased significantly by the addition of the viscra. Among the four textural properties, consistency and firmness increased with increasing size of rice; in contrast, viscosity and cohesivness decreased with increasing size of rice. However, textural properties of the porridge were not significantly different by the addition of the viscera. In the sensory evaluation, sensory scores of the porridge with round and half rice were higher than with round rice for texture, taste and total. In conclusion, concerning overall sensory evaluation, round rice porridge with 2% viscera, half rice porridge with 3% viscera and ground rice porridge with 4% viscera showed the best results, implying that developing functional abalone porridge using the viscera may be worthy.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.37-37
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• 2003

We have shown the $Ca^{2+}$-activated chloride current is present in cardiac myocyte in rabbit pulmonary vein (Kim et al., 2002). This current amplitude was increased as [N $a^{+}$]$_{i}$ was increased and we suggested this chloride current may be involve in the spontaneous action potential frequency change. Since this current is activated by the increase of intracellular $Ca^{2+}$, we would like to test what is the inducer of the increase of [C $a^{2+}$]$_{i}$ between a L-type $Ca^{2+}$-current or a reverse mode of N $a^{+}$-C $a^{2+}$ exchange current. White rabbit (1.5 kg) was used and anesthetized with Ketamin (100 mg/kg). Pulmonary vein (PV) was isolated and sleeve area between left atrium and PV was dissected. Using collagenase (Worthington 0.7 mg/cc), single cardiac myocytes were isolated. In the presence of 15 mM of N $a^{＋}$, three steps of voltage pulses were applied (holding potential : -40 ㎷, -80 ㎷ for 50 msec, 30 ㎷ for 5 msec, 10 ㎷ steps from -70 ㎷ to 60 ㎷). The inward and outward tail current was activated after brief 5 msec prepulse. The outward tail current was blocked by the removal of extracellular chloride substituted by glucuronic acid or by a chloride channel blocker, 5 mM 9-AC. But the inward tail current was still remained even though the amplitude was decreased. The reversal potentials were changed to the direction of the change of chloride equilibrium potential ( $E_{Cl}$ ) but the shift of equilibrium potential was not enough to match to the theoretical equilibrium potential shift. In the presence of L-type $Ca^{2+}$ channel blocker, nifedipine 1 uM, inward tail currents were greatly reduced but the outward current tail currents were still remained. In the presence of N $a^{+}$-C $a^{2+}$ exchange current blocker, 10 uM KB-R7943, the inward and outward tail currents were blocked almost completely. We tried to test the $Ca^{2+}$sensitivity of the chloride current with various [C $a^{2+}$]$_{i}$ in pipette solution from 100 nM to 1 uM but we failed to activate $Ca^{2＋}$-activated chloride currents even though the cell became contracted in the presence of 1 uM $Ca^{2+}$. From these results, we could conclude that the increase of [C $a^{2+}$]$_{i}$ to activate the outward $Ca^{2+}$-activated chloride current was mainly induced by the activation of the reverse mode of N $a^{+}$-C $a^{2+}$ exchanger, But for the increase of [C $a^{2+}$]$_{i}$ to activate the inward tail current, L-type $Ca^{2+}$ current may be the major provoking current. Since the cytosolic increase of [C $a^{2+}$]$_{i}$ through pipette solution have failed to activate $Ca^{2+}$-activated chloride current, this chloride current may have very low $Ca^{2+}$ sensitivity or a comparmental increase $Ca^{2+}$ such as in subsarcolemmal space may activate the chloride current. Since there are several reports and models that the increase of $Ca^{2+}$ in subsarcolemmal space would be over several to tens of uM, both possibility may be valid together.uM, both possibility may be valid together.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.31-34
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• 1979

In this study, enzymatic hydrolysis of the substrate of the waste wood of Cortinellus edodes was investigated using crude cellulase preparation of Trichoderma viride Pers. ex. Fr. SANK 16374. The crude cellulase was produced by the submerged culture process and produced in the culture fluid was salted out quantitatively by the use of ammonium sulfate. Reducing sugar was determined by the dinitrosalisylic acid (DNS) method. 1. The chemical composition of the waste wood was crude protein 2.26%, c. fat 2.57%, c. fibre 44.60%, c. ash 5.58% and lignin 13.62%. In amino acid composition, no cystine and methionine was showed, but trace amount of Vitamin A, $B_1$, and $B_2$, niacine and chloride were detected. (Table 1) 2. As heat treatment of the substrate was found to produce the highest reducing sugar yield being reacted for 48hr. with T.v cellulase, the substrate was heated to $190{\pm}5^{\circ}C$. for 45 min. either before or immediately after milling. 3. The substrate heated and ball milled at $190{\pm}5^{\circ}C$. for 45 min. the reducing sugar yield reached to 11.5%. 4. The substrate without any treatment was found to produce the highest reducing sugar yield being reacted 72hr. with T. v cellulase, the reducing sugar yield reached to 10.1%. 5. The rate of reducing sugar per each treated substrate was decreased by the order of the substrated, heated and then ball milled at $190{\pm}5^{\circ}C$. for 45 min. (11.5%)> without any treatment (10.1)> ball milled and heated at $190{\pm}5^{\circ}C$. for 45 min. (6.9%). 6. Saccharification of waste wood has been shown to be possible by heat treated and milling the substrate in contact with cellulase. And it is likely to be recommended that the waste wood may be valuable for raw materials of saccharification.

• Journal of Korean Society of Forest Science
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• v.27 no.1
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• pp.15-21
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• 1975

According to Yoshihisa Kuroki's report that the total amount of carotenoid was more in the susceptible to pine bark beetle, than in the resistant ones, carotenoids were extracted from needle leaves of one year old seedlings of Pinus thunbergii, Pinus desiflora, Pinus rigida, Pinus koraiensis, Pinus rigitaeda and Pinus taeda which are all important pines in Korea, to find their resistant ratio to the insect. The carotenoids were analyzed and compared using the spectra of them by spectrophotometer. The results were as follows: 1. The visible absorption spectra of carotenoids in those pine trees were proved to be very similar. 2. The total amount of carotenoids in needles differed with the tree species and the contents were arranged in decreasing order P. koraiensis>P. rigida>P. thunbergii>P. rigitaeda>P. taeda, it seemed that there was corelation between the cartenoid content and the extent of harm caused by the pine bark beetles except P. koraiensis. 3. But carotenoids were contained in Robinia pseudoacacia, Castanea crenata, Chamaecyparis obtusa and Cedrus deodra leaves too. 4. The total amounts of carotenoids in these pines of 9 species were arranged in decreasing order Robinia pseudoacacia>Pinus koraiensis>Pinus rigida>Pinus thunbergii>Castanea crenata>Pinus rigitaeda>Pinus taeda>Chamaecyparis obtusa>Cedrus deodara. Therefore, it was proved that there was no correlation between carotenoid cotent and extent of resistance to the insect. 5. In the thin-layer chromatography of these carotenoids, 13 kinds of components in P. densiftora, P. koraiensis and P. rigida and 12 kinds of spots in other pines, were detected respectively, under ultra-violet fluorescent lamp $3,600{\AA}$ and $2,537{\AA}$. 6. The eighth spots from the bottom in P. densiflora, P. koraiensis and P. rigida were not found in other pines and other 4 species (Robinia pseudoacacia, Castanea crenata, Chamacyparis obtusa, Cedrus deodra). Especially the spot in P. densiflora fluoresced strong cobalt blue-fluorescence under ultra-violet fluorescent lamp $2,537{\AA}$.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.415-421
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• 1997

The objectives of this study were to obtain standardized basic data on cambial electrical resistance (CER) of ornamental trees to be used for estimation of tree vigor and to compare CER between shrubs, deciduous, and coniferous trees in relation to bud opening, flowering, and growth cessation. Eighty healthy trees with four trees each for twenty ornamental tree species growing at an university campus in Suwon were selected and their CER was measured using a Shigometer every week from March to May, once a month from June to October and every two weeks in November, 1996. The CER of all tree species was high in March, started to decrease in April, maintained minimum in May through August, began to increase in September, and returned in November to the similar high level to March. Among the 20 species, Metasequoia glyptostroboides showed the lowest($5.5k{\Omega}$) annual average CER, while Cercis chinensis and Ligustrum obtusifolium had the highest($22.7k{\Omega}$, $22.9k{\Omega}$) annual average CER. The lowest CER($2.4k{\Omega}$) in summer(June through August) was obtained from Wisteria floribunda, second lowest($2.5k{\Omega}$) from Metasequoia glyptostroboides, the highest CER($46.8k{\Omega}$) during dormant season from Euonymus japonica, and second highest($45.0k{\Omega}$) obtained from Ligustrum obtusifolium. The CER of most species, particularly shrub species, started to decrease with bud opening, and many species, particularly shrubs and deciduous trees with large amount of flowers, showed sharp decrease with flowering. When CER was compared between shrubs and trees, shrubs showed higher average CER than trees, and seasonal difference in CER of evergreen species was smaller than that of deciduous species. It is interesting to note that the deciduous Metasequoia glyptostroboides had the lowest annual average CER.

• Journal of the Korean Geophysical Society
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• v.3 no.2
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• pp.99-112
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• 2000

The Iksan Jurassic Granite shows relatively less fractures and homogeneous rock fabrics, and is one of the most popular stone materials for architectures and sculptures. Almost mutually perpendicular rift, grain, and halfway in the Iksan Jurassic Granite are well known to quarrymen based on its splitting directions, and therefore it should exhibit orthorhombic symmetry. Theoretically, there are 9 independent elastic stiffness coefficients $(C_{1111},\;C_{2222},\;C_{3333},\;C_{2323},\;C_{1313},\;C_{1212},\;C_{1122},\;C_{2233},\;and\;C_{1133})$ for orthorhombic anisotropy. In order to characterize the static and dynamic elastic properties of the Iksan Jurassic Granite, triaxial strains under uniaxial compressive stresses and ultrasonic velocities of elastic waves in three different polarizations are measured. Both experiments are carried out with six directional core samples from massive rock body. Using the results of experiments and the densities measured independently, the static and dynamic elastic coefficients are computed by simple mathematical manipulation derived from the governing equations for general anisotropic media. The static elastic coefficients increase ar uniaxial compressive stress rises. Among those, the static elastic coefficients at uniaxial compressive stress of a 24.5 MPa appear to be similar to the dynamic elastic coefficients under ambient condition. Although some deviations are observed, the preferred orientations of microcracks appear to be parallel or subparallel to the rift, the grain, and the hardway from microscopic observation of thin sections. This indicates that the preferred orientations of microcracks cause the elastic anisotropy of the Iksan Jurassic Granite. The results are to be applied to the effective use of the Iksan Jurassic Granite as stone materials, and can be used for the non-destructive safety test.

• Sijohaknonchong
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• v.23
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• pp.71-105
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• 2005

Toson-Shibigok(Twelve Songs of Toson) which T'oegye, Yi Hwang, composed has received a lot of attention in terms of its educational implications. These implications have become the essential part of Gojeon Sigas(classic songs and poems), and solid evidence has also been accumulated in the literature. Therefore, the purposes of this study are twofold, that is 1) to explore the impact of T'oegye's fundamental structure of the first education at that time and 2) describe how these educational attitudes will eventually yield meta- educational values. What T'oegye meant by fundamental structure of the first education was that Sijos originated from his own experience should be the vital part of teaching method. One can say that T'oegye's teaching method is more integrative than that of modern literature education in that it includes songs. Not only using his own teaching method, but T'oegye tried to demonstrate his own literary structure to his colleagues and the future generations. In the end, Meta-Education which comprises the heart of recent educational theories well reflects Toegye's theoretical propositions. Rather than giving practical knowledge, his method offers the paradigms of thought patterns and shows the learners' attitudes in approaching the truth. Moreover, T'oegye's teaching method has become a good example to the future generations as well as his contemporary followers. In sum, although a lot of years have passed since he died, T'oegye's Sijo works and life still have invaluable impact on the field of education.