• Korean Journal of Ecology and Environment
• /
• v.51 no.1
• /
• pp.60-70
• /
• 2018

The distribution of benthic macroinvertebrates was investigated at 1,157 sites of 7 main water systems in Korea, including 442 sites of Han River system (Namhan River, Bukhan River, Han River main stream, Anseongcheon, etc.), 305 sites of Nakdong River system (Nakdong River, Hyeongsan River, Taehwa River, etc.), 199 sites of Geum River system (Geum River, Sapgyocheon, Mangyeong River, Dongjin River, etc.) 102 sites of Seomjin River system (Seomjin River), 102 sites of Yeongsan River system (Yeongsan River, Tamjin River, etc.), and 7 sites of Jeju stream system. A total of 151 families were found in the whole survey sites, including 141 families in Han River, 122 in Nakdong River, 115 in Geum River, 106 in Seomjin River, 113 in Yeongsan River, and 50 in Jeju. Chironomidae (20.8%) was the most dominant species in Korea, followed by Hydropsychidae (17.1%), Baetidae (12.6%), Tubificidae (10.3%), Heptageniidae (8.6%), Ephemerellidae (6.3%), Asellidae (2.7%), Leptophlebiidae (2.4%), Planariidae (1.7%), and Tipulidae (1.6%). Substrates compositions consisted of large sand (22.6%), large gravel (18.4%), silt (10.5%), and boulder (8.2%). The mean stream width was 133.5 m and the mean watercourse width was 61.7 m. The mean water depth and velocity were 30.2 cm and $33.1cm\;s^{-1}$, respectively. Results of cluster analysis based on distributional characteristics of benthic macroinvertebrates were divided into six groups according to the frequency of benthic macroinvertebrate taxa which appeared in the study area. Finally, altitude, current velocity and substrate composition were the most influencial factors determining the distribution patterns of macroinvertebrate communities.

• Korean Journal of Food Science and Technology
• /
• v.2 no.2
• /
• pp.17-25
• /
• 1970

Juice were extracted from fresh leaves of 70 species of plants growing in Korea by mincing and pressing the resulting pulp through a cotton cloth. Leaf protein concentrates could be prepared from many species of land and water plants that are at present economically unimportant. The choice of plants is of considerable important. Total-N, protein-N and pH determinations were made on the extracts, and total-N remaining in the fibre were calculated. Leaf protein concentrates were precipitated from the extracts at $75{\sim}80^{\circ}C$, and analysed total-N as protein-N of products. The present paper deals with the calculated yields of leaf protein concentrates from various plants, relations between yield of leaf protein concentrates and total-N of leaves, or pH of extracts, and the amino acid compositions of leaf protein concentrates. Results are summarized as follows. 1. Spinach and radish were the best sources of easily extractable, but good results were also obtained with indian mustard, kail, chenopod, red bean, cucumber, squash, houndberry, white flowered gourd, potato, Humulus japonicus, arrowroot and soybean as a good resources for the production of leaf protein concentrates. 2. In general, the greater the protein content of leaves the greater the yield of leaf protein concentrates. However, there are some plants difficult to make a adequate protein extraction by a simple mechanical process. 3. It was to be expected that leaf protein concentrates would be more extractable with the higher pH of extracts. There were a poor yield of the leaf protein concentrate in the pH values lower than 5.50 of the first extracts. 4. Protein content of the leaf protein concentrate shows marked differences, depending on species and season. It ranged between 29 to 80% of protein contents. However, the majority of plants yielded products containing more than 50% of protein. Products containing more than 75% of protein were obtained from two species of radish and indian mustard. Cabbage and Digitaria sanguinalis cilialis (summer) made products containing 29 to 32% of protein. 5. The amino acid composition of leaf protein concentrates was not greatly altered by species of plants. On an amino acid compositional basis, the leaf protein concentrate has a favorable balance of essential and non-essential amino acids, the only exception being methionine, which was usually low in all cases.

• Journal of fish pathology
• /
• v.8 no.2
• /
• pp.119-134
• /
• 1995

To induce an overpopulated melanomacrophage centers(MMCs) within spleen and kidney in tilapias, two methods were applied through the intraperitoneal inoculation of V. anguillarum FKC with a repeated dose of saline(the 1st induction group), and of colloidal carbon (the 2nd induction group). In the 1st group, both number and size of MMCs were slightly increased in spleen and head kidney. However in the 2nd group the two hemopoietic tissues were nearly occupied with quite a large number of MMCs. Regardless of induction groups, many of MMCs were confined within the walls of blood vessels in the spleen. Especially in the 2nd group, the MMCs without fibrous capsules often had concentrically or eccentrically located, thin-walled lumens of vessels, which strongly suggests to be ellipsoids. In head kidney, nearly all MMCs were located within or just around the lymphocytic areas but the precise relationship to blood vessel wall was not obvious. Despite of such overpopulated MMCs, no histopathological degenerative findings in hemopoetic parenchymas of both organs were recognized. To evaluate the effect on defensive function, tilapias of the 2nd group were challenged with E. tarda. Susceptabilities to E. tarda were never increased but rather significantly decreased compared to control. Weekly antibody titres in sera were determined for all induction groups, in which the titres in the 1st and 2nd groups were 4 or 8 times higher than in the control, and then remained high until the 4th week. Also with the hemopoietic function, cellular compositions of peripheral blood were analyzed at weekly intervals but no significant changes resulted. From those results, it is suggested that overcrowding of MMCs would not lead to any morphological as well as functional deteriorations of spleen and head kidney but have an intimate association with enhancement of protective immune system in tilapias.

• Applied Biological Chemistry
• /
• v.32 no.1
• /
• pp.14-22
• /
• 1989

Chemical composition of the oyster mushroom(Pleurotus spp.) at different cropping stage were analyzed. The contents of crude protein, soluble protein, reducing sugar, total sugar and crude fat in Pleurotus ostreatus 201 were a little higher than those of Pleurotus sajorcaju. The Component contents were not different from the first to the second flush, while the contents were slightly decreased from the third flush. A11 component contents were highest in $3{\sim}5cm$ pileus size, the contents were slightly decreased as pileus size increase to over $3{\sim}5cm$, except for reducing sugar. Crude fiber content in Pleurotus sajor-caju were a little more than Pleurotus ostreatus 201, and in course of increasing cropping time, ash contens of two strains were simmilar, and were decreased after the second flush. These component contents mere increased by the growth of the pileus. The sugars were identified as xylose, glucose, mannitol and trehalose in Pleurotus sajor-caju, and xylose, fructose, glucose, mannitol and trehalose in Pleurotus ostreatus 201, respectively. Mannitol and trehalose contents in Pleurotus sajor-caju were a little more than that in Pleurotus ostreatus 201. Glucose content of Pleurotus sajor-caju and Pleurotus ostreatus 201 was highest in $1{\sim}3cm$ pileus size, while other sugars in $3{\sim}5cm$ pileus size, and the sugar contents were decreased at over the above size of the pileus.

• The Journal of the Petrological Society of Korea
• /
• v.4 no.1
• /
• pp.61-87
• /
• 1995

On the basis of lithology, the Precambrian Hongjesa Granitic Gneiss can be locally zoned into granoblastic granitic gneiss, porphyroblastic granitic gneiss, migmatitic gneiss from its center to the marginal part. There are no distinct differences in mineral assemblages by lithologic zoning, but it partly shows the change of mineral assemblage in the adjacent with migmatitic gneiss, thus mineral assemblage can be subdivided into Zone I and Zone II. In terms of mineral compositions, the characteristics of Zone I are coexisting K-feldspar+muscovite+sillimanite. The characteristics of Zone II are (1) breakdown of muscovite, (2) coexisting garnetScordierite, (3) coexisting garnet+cordierite + orthoamphibole. The Buncheon Granitic Gneiss is mainly composed of augen gneiss. In the adjacent area with Honjesa Granitic Gneisses, Buncheon Granitic Gneiss has the mineral assemblage of sillimanite+biotite+K-feldspar+(kyanite). Kyanite occurs as relict grains in the Buncheon and Hongjesa Granitic Gneissess. Kyanite shows anhedral to subhedral form and coexists with sillimanite in only one of these samples. Garnet from a migmatitic gneiss (Zone 11) has relatively high $X_{Fe}$ value in core and rim. Garnet from a porphyroblastic granitic gneiss(Zone I) has relatively homogemeous core but compositionally-zoned rim. Biotites show various colour from greenish-brown, brown to reddish brown at maximum adsorption. Also, the Ti, and Mg content in biotites increases from Zone I to Zone II. The plagioclases shows the chemical composition of $Ab_{84}An_{16}$ -$Ab_{70}An_{30}$ (oligoclase) in Zone I and $Ab_{70}An_{30}$ -$Ab_{50}An_{50}$(andesine) in Zone 11. These variations indicate that the gneisses in the study area experienced a upperamphibolite facies. The presence of kyanite as relict grains indicates that the metamorphic rocks in this area exprienced a high-temperature/medium-pressure type metamorphism, followed by high-temperaturellow-pressure metamorphism. Metamorphic P-T conditions for each gneiss estimated from various geothermobarometers and phase equilibria are 698-$729^{\circ}C$/6.3-11.3 kbar in augen gneiss, 621-$667^{\circ}C$/1.0-5.4 kbar in migmatitic gneiss, and 602-$624^{\circ}C$/1.9-3.4 kbar in porphyroblastic granitic gneiss. These data suggest that the study area was subjected to a clockwise P-T path with isothermal decompression (dP/dT=about 60 bar/$^{\circ}C$).

• Korean Journal of Veterinary Research
• /
• v.32 no.4
• /
• pp.531-542
• /
• 1992

The present study was performed to identify the factors influencing on early pregnacy and embryo implantation in rabbit. Serum, uterine fluid, and uterine tissue were collected on day 0, 3, 5, 7 and 9 of pregnancy. The intrauterine environment of receptive phase and refractory phase was compared by measuring protein synthetic capacity of endometrium, amino acid composition and concentrations of lipids(phospholipid, cholesterol). The results obstained were as follows : 1. The concentrations of total protein were significantly increased (p<0.01) on day 5 ($7.00{\pm}0.55$), 7($6.29{\pm}0.65$), and 9($6.34{\pm}0.61$), compared to those on day 0($5.50{\pm}0.12g/100m{\ell}$) in serum. The concentration of albumin on day 0 was $0.81{\pm}0.05$ and reached maximum on day 5 ($1.59{\pm}0.07g/100m{\ell}$) in serum. The concentrations of total protein were significantly increased(p<0.01) on day 5($1.56{\pm}0.10$), 7($1.99{\pm}0.22$), compared to those on day 0($0.38{\pm}0.02g/100m{\ell}$) in uterine fluid. The concentration of albumin on day 5($0.78{\pm}0.05g/100m{\ell}$) was higher than those on the other days in uterine fluid. 2. The incorporation rates of [$^3H$]-leucine into protein were significantly increased(p<0.01) on day 5 ($919.6{\pm}97.5$), 7($1445.4{\pm}95.9$) and 9($450.38{\pm}28.71$), compared to those on day 0($328.2{\pm}38.9cpm/mg$ protein) in endometrium. The incorporation rates in colehicine-treated endometrium on day 5 ($1341.9{\pm}73.8$), 7($1729.4{\pm}63.3cpm/mg$ protein) were significantly higher(p<0.01) than those on the other days. 3. The compositions of amino acid were not distinctly changed during early pregnancy in serum. The composition ratios of methione, lysine were distinctly decreased on day 3, compared to those on day 0 in uterine fluid. Those of glycine, alanine were increased on day 9, compared to those on other days but his tidine decreased in uterine fluid. 4. The concentrations of total phospholipid and total cholesterol were significantly decreased(p<0.01) on day 3($77.9{\pm}15.5$, $61.5{\pm}21.2$), compared to those on day 0($164.0{\pm}33.9$, $167.2{\pm}46.2mg/100m{\ell}$)in serum. The concentrations of total phospholipid and total cholesterol on day 9 ($47.3{\pm}13.4$, $37.7{\pm}9.6mg/100m{\ell}$) were significantly higher(p<0.01) than those on the other days in uterine fluid. 5. Total phopholipid/total cholesterol ratios were not significantly changed during early pregnancy in serum. However, total phospholipid/total cholesterol ratios on day 5 ($2.00{\pm}0.42$), 7 ($1.11{\pm}0.77$) and 9 ($1.47{\pm}0.30$) were higher than those on day 3($0.84{\pm}0.41$) in uterine fluid. 6. The concentrations of phosphatidylcholine and phosphatidylserine were significantly increased (p<0.01) on the other days, compared to those on day 0 during early pregnancy in serum. The concentrations of phosphatidylcholine were significantly increased(p<0.01),compared to those on day 0 and those of phosphatidyl-ethanolamine were consistently increased but not significant in early pregnancy in uterine fluid.

• Journal of the Mineralogical Society of Korea
• /
• v.24 no.3
• /
• pp.235-244
• /
• 2011

A batch experiment of pyrite oxidation was performed and the surfaces of the reacted pyrite were regularly observed with the scanning electron microscope (SEM) together with the chemical compositions of the solution to help understand the oxidation mechanisms of pyrite by Acidithiobacillus ferrooxidans (Af). The dissolved Fe concentrations clearly indicated that Af experiences the lag and then exponential growth phase. An Af cell was observed to be attached to the surface of pyrite during the lag, implying that a direct leaching by the microbe really happens for the period. It is not certain, however, whether the main mechanism of pyrite oxidation during that time was the direct leaching or not, because there were just a few cells confirmed to be attached and most of the dissolved Fe was Fe(III). The dissolved Fe concentration stayed almost constant from the mid-lag phase to just before the onset of the exponential phase, suggesting that AI needs an adaptation time to switch its oxidation mechanism from one to the other whichever it is during that stage of growth. The moment of Af's cell division was observed by SEM on the surface of pyrite during the lag phase. The corrosion outline around the dividing cell was quite similar to the shape of the cell itself, which implies that the rate of the microbial oxidation is very uneven and the rate when the cell metabolizes should be much faster than that calculated from the concentration variation of the dissolved Fe. The number of etch holes by Af is much higher on the inoculated surfaces, indicating the average rate of pyrite oxidation is also much faster than that of abiotic oxidation. The microbial etch holes on pyrite surface are small and deep, which may influence the transition of the growth phases of Af from lag to exponential.

• Analytical Science and Technology
• /
• v.23 no.4
• /
• pp.371-382
• /
• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.1
• /
• pp.83-90
• /
• 2020

The Graphite Isotope Ratio Method (GIRM) can verify non-proliferation of nuclear weapon by estimating the total plutonium production in a graphite-moderated reactor. Using the reactor, plutonium is generated and accumulated through the ²³⁸U neutron capture reaction, and impurities in the graphite are converted to nuclides due to the nuclear reaction. Therefore, the amount of plutonium production and concentration of the impurities are correlated. However, the plutonium production cannot be predicted using only the absolute concentration of the impurities. It can only be predicted when the initial concentration of the impurities is obtained because the concentration, at a certain time, depends on it. Nevertheless, the ratios of the isotopes in an element are known regardless of the impurity of an element in the graphite moderator. Thus, the correlation between the isotope ratio and amount of plutonium produced helps predict plutonium production in a graphite-moderated reactor. Boron, Lithium, Chlorine, Titanium, and Uranium are known as indicator elements in the GIRM. To assess whether the correlation between the indicator isotope and amount of plutonium produced is independent of the initial concentration of the impurities, four different impurity compositions of graphite were used. ¹⁰B/¹¹B, ³⁶Cl/³⁵Cl, ⁴⁸Ti/⁴⁹Ti, and ²³⁵U/²³⁸U had a consistent correlation with the cumulative plutonium production, regardless of the initial impurity concentration of the graphite, because these isotopes were not generated through the nuclear reaction of other elements. On the other hand, the correlation between ⁶Li/⁷Li and plutonium production depended on the initial concentration of the impurities in graphite. Although ⁷Li can be produced through the neutron capture reaction of ⁶Li, the (n, α) reaction of ¹⁰B was the major source of ⁷Li. Therefore, the initial concentration of ¹⁰B affected the production of ⁷Li, making Li unsuitable as an indicator element for the GIRM.

• Applied Biological Chemistry
• /
• v.38 no.2
• /
• pp.141-146
• /
• 1995

Changes of physicochemical properties of citron juice prepared by two different extraction methods, rotary-crushing and belt-pressing method, were investigated during the storage at $5^{\circ}C$ and $-20^{\circ}C$. Temperature drop of citron juice extracted by belt-pressing method was faster than that of citron juice prepared by rotary-crushing method and its freezing point was $0.8{\sim}0.9^{\circ}C$. During the storage, pH of stored citron juice with rotary-crushing method was increased up to 3.5 after 6 months storage while that of citron juice extracted by belt-pressing method was not changed significantly during the same storage time. Acidity of rotary-crushed citron juice was reduced a little more than that of belt-pressed citron juice during the storage. However, changes of soluble solid content were influenced largely by the storage temperature than by the extraction method. Contents of formol nitrogen and vitamin C were reduced remarkably in all of stored citron juice and $92{\sim}82%$ of farmol nitrogen and $72{\sim}43%$ of vitamin C were remained after 6 months of storage. Among the changes of color value, L values were reduced in the whole stored citron juice and a and b value had a different change pattern respectively according to the extraction and storage temperature. Changes in the content of both amino acid and fatty acid compositions was also observed after same storage period. Especially, in the case of change of fatty acid composition, content of linoleic acid and linolenic acid were reduced after 6 months storage, while those of palmitic acid, stearic acid and oleic acid were increased.