• Applied Biological Chemistry
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• v.22 no.2
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• pp.65-90
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• 1979

This study was conducted to establish the brewing method which would be useful for the production of Kochuzang. Kojis, which were made from various materials and microorganisms under a covered condition, were investigated and compared. Yeasts (Saccharomyces rouxii and Torulopsis versatilis) were added to Kochuzang, and the enzyme activity, microflora, chemical composition, nitrogen content, alcohol content and free sugars of Kochuzang were investigated and analysed. The results obtained are as follows: 1. Koji making (1) Glutinous rice-soybean group was superior to glutinous rice group in the saccharogenic and liquefying amylase activities of three day-Koji. (2) Protease activity (acid, neutral and alkaline) of glutinous rice-soybean Koji, which was inoculated with Aspergillus oryzae A, was increased till the 5th day, while other groups showed maximum activity after the 3rd day. (3) The maximum cellulose activity of Aspergillus oryzae B-Koji and A-Koji was observed after the 2nd day and the 3rd day, respectively. High cellulose activity of Aspergillus oryzae B-Koji and A-Koji was respectively shown in glutinous rice group and glutinous rice-soybean group at maximum. (4) Compared with glutinous rice Koji, glutinous rice-soybean Koji gave larger number of yeast and aerobic bacteria. 2. Kochuzang Fermentation (1) Each Kochuzang group shoved different liquefying and saccharogenic amylase activities. The highest activities were generally shown in 10 to 40 days after mashing and remarkably reduced in the last stage of aging. (2) Protease activities of each group were strong in order of acid, neutral and alkaline protease. Especially acid protease showed highest activity at the 40th to 50th day Kochuzang. (3) Each group showed maximum cellulase activity in the 40th and 50th day-Kochuzang and then decreased. (4) Osmophilic yeast of yeast-added Kochuzang after one-month aging was distinctively outnumbered compared with non-yeast-added Kochuzang, but two groups were similar after two months. (5) Yeast-added group and non-added group gave almost the same number of halophilic lactic acid bacteria in Kochuzang, but the non-added group gave slightly larger number of aerobic bacteria than the yeast-added group. (6) Amino nitrogen contents in all test group were increased rapidly till the 60th day of Kochuzang aged. After that the contents were increased slowly. (7) Ethyl alcohol contents of 20day-fermented Kochuzang were high in order of Saccharomyces rouxii-added group, Torulopsis versatilis-added group, Saccharomyces rouxii and Torulopsis versatilis mixed group and non-yeast-added group. But all test group showed about 2% in ethyl alcohol content after 40days of aging. (8) Alcohol content in the 7 month-aged Kochuzang of all test groups was high in order of ethyl alcohol, n-butyl alcohol, n-propyl alcohol and iso-propyl alcohol. Torulopsis versatilis-added group had the highest value of ethyl alcohol, n-propyl alcohol and n-butyl alcohol. (9) Reducing sugar in Kochuzang was increased after 20 days of aging compared with the 10days-ferment. The reducing sugar content in Saccharomyces rouxii-added group was distinctively small compared with that of other groups, decreasing after 30days of aging. (10) Rhamnose, fructose, glucose and maltose were isolated from the 10 day fermented Kochuzang. Raffinose was also found after 300 days-aged group, and fructose content was high in the 300days-aged Kochuzang. However, glucose content was smaller than that of 10days-fermented Kochuzang. (11) For the organoleptic tests of Kochuzang, taste, flavour and color of yeast-added group were superior to the non yeast-added group. Especially the complex yeast group among the yeast added groups were the best of all. Yeast-added group after 300 days of aging took higher paint in flavour test than that of non-added group. Therefore, brewing method like complex yeast added group seems to be advantageous for short time brewing Kochuzang.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.486-492
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• 2007

Seminal plasma(SP) is usually removed from semen that is to be cryopreserved. However, some reports indicate that SP has beneficial effects on spermatozoa during chilling and freezing. The purpose of this study was to determine the effect of SP on sperm survival by adding SP to the extender before cooling and freezing canine spermatozoa. In replicate experiments, ejaculates obtained from four healthy dogs(1-4 years old) of various breeds were pooled, centrifuged at $300{\times}g$ for 10 min at $25^{\circ}C$, and the supernatant of seminal plasma was decanted. Spermatozoa were suspended in egg yolk-Tris(EYT) buffer. The study comprised two experiments: [Exp 1] Sperm were suspended in EYT extender containing either 0, 20, 40, 80 or 100% SP and were slowly cooled to $4^{\circ}C$ for 2h or held at $25^{\circ}C$ as controls. Sperm concentration was adjusted to $2{\times}10^8/ml$. [Exp II] Sperm samples, each of which contained $1{\times}10^8/ml$, were assigned to nine groups to be frozen. In the first four groups, sperm in EYT containing either 20, 40, 80 or 100% SP were cooled to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol and then were frozen. The final concentrations of SP were 10, 20, 40 or 50%. In the other four groups, sperm in EYT alone were first cooled slowly to $4^{\circ}C$, then diluted to contain final concentrations of EYT+0.6M glycerol plus 10, 20, 40 or 50% SP and then were frozen. Spermatozoa, which chilled in EYT alone and diluted to contain final concentrations of EYT+0.6M glycerol without seminal plasma, and then frozen, was regarded as control. Spermatozoa were frozen at $25^{\circ}C/min$ of cooling rate in plastic straws that were suspended above liquid nitrogen and thawed in water at $38^{\circ}C$ for 1 min. Sperm survival was assayed by determining progressive motility and integrity of plasma and acrosome membranes. Progressive motility was determined by microscopic examination at $200{\times}$ magnification. Membrane integrity was assessed by use of a double fluorescent dye, and acrosome integrity by staining sperm with Pisum sativum agglutinin. The results of the first experiment showed that adding SP did not improve motility of spermatozoa compared to those incubated without SP regardless of temperature. The results of the second experiment showed that spermatozoa suspended in EYT+0.6M glycerol containing SP exhibited the higher progressive motility before being frozen(P<0.05). However, frozen-thawed spermatozoa that had suspended in EYT+0.6M glycerol containing SP showed the similar or lower viability(P<0.05). In summary, although seminal plasma did not affect spermatozoa that were chilled in EYT without cryoprotectant(CPA), addition of seminal plasma to EYT containing CPA did significantly improved progressive motility of canine spermatozoa that were chilled.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.4
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• pp.181-195
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• 2005

To study the effects of aquaculture activity of marine cage fish farms on marine environment, field researches including hydrography, sediment, benthos and trap experiment at the marine cage fish farms(Site A) around estuaries of Tongyeong city were carried out during June $26\~27$, 2003. A simulation using numerical model-DEPOMOD was conducted to predict the solid deposition from fish cage and to assess the probable solid deposition, and the efficiency of environmental management of marine cage fish farms was studied. The marine cage fish farms cultured mainly common sea bass (Lateolabrax japonicus), red seabream (Pagrus major), striped breakperch (Oplegnathus fasciatus) and black rockfish(Sebastes schlegeli), and total amount of cultured fish of the Site A were 23.1MT. The amount of husbandry fish by unit area(and volume) of the fish cage was $43.0kg\;m^{-2}(6.1kg\;m^{-3})$. The daily mean amounts of food fed by unit biomass and cage area were $30.8g\;kg^{-1}day^{-1},\;1.32kg\;m^{-2}day^{-1},$ respectively, at the Site A. The concentration of ORP of the sediment below the center at the Site A was -334.6 mV and the concentrations of AVS, COD, Carbon and Nitrogen were $0.43mg\;g^{-1}dry,\;17.75mg\;g^{-1}dry,\;10.19mg\;g^{-1}dry\;and\;3.49mg\;g^{-1}dry$, respectively. Capitella capitata was dominant benthic species which occupied $57.8\%$ of total species, and the Infaunal Trophical Index(ITI) was marked below 20 within 20 m distance from the edge of the Site A. The result of trap experiment, the solid deposition from the Site A was $34,485g\;m^{-2}yr^{-1}$ at 0 m from the center of the cage and $18,915g\;m^{-2}yr^{-1}$ at 42 m. From a model simulation, it was estimated that using a model simulation, the proportion of unfed food was $40\%$ at the Site A and the annual total amount of solid deposition was 63,401 accounting for $24.4\%$ of the annual total food fed at the Site A. The area solid deposition settled was estimated to be $8,450m^2$, which was about 16 times of the total area of fish cage at the Site A. And concerning ITI and abundance of benthos, the model predicted that sustainable solid flux at the Site A was below $10,000gm^{-2}yr^{-1}$. The percentage of food wasted was main element of solid deposition at the marine cage fish farms, and for minimizing solid deposition it is necessary to increase the efficiency of the food uptake. Based on the result of the model simulation, if the percentage of food wasted decreases to $10\%$ from the current $40\%$, then the solid deposition could decrease to a half. In addition, it was predicted that if farmers use EP pellets as food fed instead of MP and fish trash, solid deposition could decrease by $57\%$. Also this study proposes that the cage facility ratio of the licensed area be decreased to less than $5\%$ to minimize the sediment pollution.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.1-26
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• 2009

We conclude the following with air pollution data measured from city measurement net administered and managed in Gwangju for the last 7 years from January in 2001 to December in 2007. In addition, some major statistics governed by Gwangju city and data administered by Gwangju as national official statistics obtained by estimating the amount of national air pollutant emission from National Institute of Environmental Research were used. The results are as follows ; 1. The distribution by main managements of air emission factory is the following ; Gwangju City Hall(67.8%) > Gwangsan District Office(13.6%) > Buk District Office(9.8%) > Seo District Office(5.5%) > Nam District Office(3.0%) > Dong District Office(0.3%) and the distribution by districts of air emission factory ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%). That by types(Year 2004~2007 average) is also following ; Type 5(45.2%) > Type 4(40.7%) > Type 3(8.6%) > Type 2(3.2%) > Type 1(2.2%) and the most of them are small size of factory, Type 4 and 5. 2. The distribution by districts of the number of car registrations is the following ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%) and the distribution by use of car fuel in 2001 ; Gasoline(56.3%) > Diesel(30.3%) > LPG(13.4%) > etc.(0.2%). In 2007, there was no ranking change ; Gasoline(47.8%) > Diesel(35.6%) > LPG(16.2%) >etc.(0.4%). The number of gasoline cars increased slightly, but that of diesel and LPG cars increased remarkably. 3. The distribution by items of the amount of air pollutant emission in Gwangju is the following; CO(36.7%) > NOx(32.7%) > VOC(26.7%) > SOx(2.3%) > PM-10(1.5%). The amount of CO and NOx, which are generally generated from cars, is very large percentage among them. 4. The distribution by mean of air pollutant emission(SOx, NOx, CO, VOC, PM-10) of each county for 5 years(2001~2005) is the following ; Buk District(31.0%) > Gwangsan District(28.2%) > Seo District(20.4%) > Nam District(12.5%) > Dong District(7.9%). The amount of air pollutant emission in Buk District, which has the most population, car registrations, and air pollutant emission businesses, was the highest. On the other hand, that of air pollutant emission in Dong District, which has the least population, car registrations, and air pollutant emission businesses, was the least. 5. The average rates of SOx for 5 years(2001~2005) in Gwangju is the following ; Non industrial combustion(59.5%) > Combustion in manufacturing industry(20.4%) > Road transportation(11.4%) > Non-road transportation(3.8%) > Waste disposal(3.7%) > Production process(1.1%). And the distribution of average amount of SOx emission of each county is shown as Gwangsan District(33.3%) > Buk District(28.0%) > Seo District(19.3%) > Nam District(10.2%) > Dong District(9.1%). 6. The distribution of the amount of NOx emission in Gwangju is shown as Road transportation(59.1%) > Non-road transportation(18.9%) > Non industrial combustion(13.3%) > Combustion in manufacturing industry(6.9%) > Waste disposal(1.6%) > Production process(0.1%). And the distribution of the amount of NOx emission from each county is the following ; Buk District(30.7%) > Gwangsan District(28.8%) > Seo District(20.5%) > Nam District(12.2%) > Dong District(7.8%). 7. The distribution of the amount of carbon monoxide emission in Gwangju is shown as Road transportation(82.0%) > Non industrial combustion(10.6%) > Non-road transportation(5.4%) > Combustion in manufacturing industry(1.7%) > Waste disposal(0.3%). And the distribution of the amount of carbon monoxide emission from each county is the following ; Buk District(33.0%) > Seo District(22.3%) > Gwangsan District(21.3%) > Nam District(14.3%) > Dong District(9.1%). 8. The distribution of the amount of Volatile Organic Compound emission in Gwangju is shown as Solvent utilization(69.5%) > Road transportation(19.8%) > Energy storage & transport(4.4%) > Non-road transportation(2.8%) > Waste disposal(2.4%) > Non industrial combustion(0.5%) > Production process(0.4%) > Combustion in manufacturing industry(0.3%). And the distribution of the amount of Volatile Organic Compound emission from each county is the following ; Gwangsan District(36.8%) > Buk District(28.7%) > Seo District(17.8%) > Nam District(10.4%) > Dong District(6.3%). 9. The distribution of the amount of minute dust emission in Gwangju is shown as Road transportation(76.7%) > Non-road transportation(16.3%) > Non industrial combustion(6.1%) > Combustion in manufacturing industry(0.7%) > Waste disposal(0.2%) > Production process(0.1%). And the distribution of the amount of minute dust emission from each county is the following ; Buk District(32.8%) > Gwangsan District(26.0%) > Seo District(19.5%) > Nam District(13.2%) > Dong District(8.5%). 10. According to the major source of emission of each items, that of oxides of sulfur is Non industrial combustion, heating of residence, business and agriculture and stockbreeding. And that of NOx, carbon monoxide, minute dust is Road transportation, emission of cars and two-wheeled vehicles. Also, that of VOC is Solvent utilization emission facilities due to Solvent utilization. 11. The concentration of sulfurous acid gas has been 0.004ppm since 2001 and there has not been no concentration change year by year. It is considered that the use of sulfurous acid gas is now reaching to the stabilization stage. This is found by the facts that the use of fuel is steadily changing from solid or liquid fuel to low sulfur liquid fuel containing very little amount of sulfur element or gas, so that nearly no change in concentration has been shown regularly. 12. Concerning changes of the concentration of throughout time, the concentration of NO has been shown relatively higher than that of $NO_2$ between 6AM~1PM and the concentration of $NO_2$ higher during the other time. The concentration of NOx(NO, $NO_2$) has been relatively high during weekday evenings. This result shows that there is correlation between the concentration of NOx and car traffics as we can see the Road transportation which accounts for 59.1% among the amount of NOx emission. 13. 49.1~61.2% of PM-10 shows PM-2.5 concerning the relationship between PM-10 and PM-2.5 and PM-2.5 among dust accounts for 45.4%~44.5% of PM-10 during March and April which is the lowest rates. This proves that particles of yellow sand that are bigger than the size $2.5\;{\mu}m$ are sent more than those that are smaller from China. This result shows that particles smaller than $2.5\;{\mu}m$ among dust exist much during July~August and December~January and 76.7% of minute dust is proved to be road transportation in Gwangju.

• Korean Journal of Weed Science
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• v.13 no.4
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• pp.210-233
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• 1993

The herbicide has become indispensable as much as nitrogen fertilizer in Korean agriculture from 1970 onwards. It is estimated that in 1991 more than 40 herbicides were registered for rice crop and treated to an area 1.41 times the rice acreage ; more than 30 herbicides were registered for field crops and treated to 89% of the crop area ; the treatment acreage of 3 non-selective foliar-applied herbicides reached 2,555 thousand hectares. During the last 25 years herbicides have benefited the Korean farmers substantially in labor, cost and time of farming. Any herbicide which causes crop injury in ordinary uses is not allowed to register in most country. Herbicides, however, can cause crop injury more or less when they are misused, abused or used under adverse environments. The herbicide use more than 100% of crop acreage means an increased probability of which herbicides are used wrong or under adverse situation. This is true as evidenced by that about 25% of farmers have experienced the herbicide caused crop injury more than once during last 10 years on authors' nationwide surveys in 1992 and 1993 ; one-half of the injury incidences were with crop yield loss greater than 10%. Crop injury caused by herbicide had not occurred to a serious extent in the 1960s when the herbicides fewer than 5 were used by farmers to the field less than 12% of total acreage. Farmers ascribed about 53% of the herbicidal injury incidences at their fields to their misuses such as overdose, careless or improper application, off-time application or wrong choice of the herbicide, etc. While 47% of the incidences were mainly due to adverse natural conditions. Such misuses can be reduced to a minimum through enhanced education/extension services for right uses and, although undesirable, increased farmers' experiences of phytotoxicity. The most difficult primary problem arises from lack of countermeasures for farmers to cope with various adverse environmental conditions. At present almost all the herbicides have"Do not use!" instructions on label to avoid crop injury under adverse environments. These "Do not use!" situations Include sandy, highly percolating, or infertile soils, cool water gushing paddy, poorly draining paddy, terraced paddy, too wet or dry soils, days of abnormally cool or high air temperature, etc. Meanwhile, the cultivated lands are under poor conditions : the average organic matter content ranges 2.5 to 2.8% in paddy soil and 2.0 to 2.6% in upland soil ; the canon exchange capacity ranges 8 to 12 m.e. ; approximately 43% of paddy and 56% of upland are of sandy to sandy gravel soil ; only 42% of paddy and 16% of upland fields are on flat land. The present situation would mean that about 40 to 50% of soil applied herbicides are used on the field where the label instructs "Do not use!". Yet no positive effort has been made for 25 years long by government or companies to develop countermeasures. It is a really sophisticated social problem. In the 1960s and 1970s a subside program to incoporate hillside red clayish soil into sandy paddy as well as campaign for increased application of compost to the field had been operating. Yet majority of the sandy soils remains sandy and the program and campaign had been stopped. With regard to this sandy soil problem the authors have developed a method of "split application of a herbicide onto sandy soil field". A model case study has been carried out with success and is introduced with key procedure in this paper. Climate is variable in its nature. Among the climatic components sudden fall or rise in temperature is hardly avoidable for a crop plant. Our spring air temperature fluctuates so much ; for example, the daily mean air temperature of Inchon city varied from 6.31 to $16.81^{\circ}C$ on April 20, early seeding time of crops, within${\times}$2Sd range of 30 year records. Seeding early in season means an increased liability to phytotoxicity, and this will be more evident in direct water-seeding of rice. About 20% of farmers depend on the cold underground-water pumped for rice irrigation. If the well is deep over 70m, the fresh water may be about $10^{\circ}C$ cold. The water should be warmed to about $20^{\circ}C$ before irrigation. This is not so practiced well by farmers. In addition to the forementioned adverse conditions there exist many other aspects to be amended. Among them the worst for liquid spray type herbicides is almost total lacking in proper knowledge of nozzle types and concern with even spray by the administrative, rural extension officers, company and farmers. Even not available in the market are the nozzles and sprayers appropriate for herbicides spray. Most people perceive all the pesticide sprayers same and concern much with the speed and easiness of spray, not with correct spray. There exist many points to be improved to minimize herbicidal phytotoxicity in Korea and many ways to achieve the goal. First of all it is suggested that 1) the present evaluation of a new herbicide at standard and double doses in registration trials is to be an evaluation for standard, double and triple doses to exploit the response slope in making decision for approval and recommendation of different dose for different situation on label, 2) the government is to recognize the facts and nature of the present problem to correct the present misperceptions and to develop an appropriate national program for improvement of soil conditions, spray equipment, extention manpower and services, 3) the researchers are to enhance researches on the countermeasures and 4) the herbicide makers/dealers are to correct their misperceptions and policy for sales, to develop database on the detailed use conditions of consumer one by one and to serve the consumers with direct counsel based on the database.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.1
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• pp.1-13
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• 2006

A field survey on the spatio-temporal distribution characteristics and origins of organic matter in surface sediments was carried out monthly at six stations in Gamak Bay, South Korea from April 2000 to March 2002. The range of ignition loss(IL) was $4.6{\sim}11.6%(7.1{\pm}1.6%)$, while chemical oxygen demand(CODs) ranged from $12.25{\sim}99.26mgO_2/g-dry(30.98{\pm}19.09mgO_2/g-dry)$, acid volatile sulfide(AVS) went from no detection(ND)${\sim}10.29mgS/g-dry(1.02{\pm}0.58mgS/g-dry)$, and phaeopigment was $6.84{\sim}116.18{\mu}g/g-dry(23.72{\pm}21.16{\mu}g/g-dry)$. The ranges of particulate organic carbon(POC) and particulate organic nitrogen(PON) were $5.45{\sim}23.24 mgC/g-dty(10.34{\pm}4.40C\;mgC/g-dry)$ and $0.71{\sim}2.99mgN/g-dry(1.37{\pm}0.58mgN/g-dry)$, respectively. Water content was in the range of $43.1{\sim}77.6%(55.8{\pm}5.6%)$, and mud content(silt+clay) was higher than 95% at all stations. The spatial distribution of organic matter in surface sediments was greatly divided between the northwestern, central and eastern areas, southern entrance area from the distribution characteristic of their organic matters. The concentrations of almost all items were greater at the northwestern and southern entrance area than at the other areas in Gamak Bay. In particular, sedimentary pollution was very serious at the northwestern area, because the area had an excessive supply of organic matter due to aquaculture activity and the inflow of sewage from the land. These materials stayed longer because of the topographical characteristics of such as basin and the anoxic conditions in the bottom seawater environment caused by thermocline in the summer. The tendency of temporal change was most prominently in the period of high-water temperatures than low-water ones at the northwestern and southern entrance areas. On the other hand, the central and eastern areas did not show a regular trend for changing the concentrations of each item but mainly showed a higher tendency during the low-water temperatures. This was observed for all but AVS concentrations which were higher during the period of high-water temperature at all stations. Especially, the central and eastern areas showed a large temporal increase of AVS concentration during those periods of high-water temperature where the concentration of CODs was in excess of $20mgO_2/g-dry$. The results show that the organic matters in surface sediments in Gamak Bay actually originated from autochthonous organic matters with eight or less in average C/N ratio including the organic matters generated by the use of ocean, rather than terrigenous organic matters. However, the formation of autochthonous organic matter was mainly derived from detritus than living phytoplankton, indicated the results of the POC/phaeopigment ratio. In addition, the CODs/IL ratio results demonstrate that the detritus was the product of artificial activities such as dregs feeding and fecal pellets of farm organisms caused by aquaculture activities rather than the dynamic of natural ocean activities.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.47-72
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• 1991

To obtain the principal data for useful treatment and processing of Korean geoduck (Panope japonica A. ADAMS) which inhabit mostly at Dong-Hae coastal area in Korea, changes of $NH_2$-N, TMAO, TMA, total creatinine, protein composition and fatty acid composition in raw and blanched geoduck muscle during storage at $-20^{\circ}C$ were investigated. In addition, its chemical composition variation in the whole year was elucidated. The moisture content in geoduck muscle meat was 78.1% to 82% in the whole year. Particularly, in July its moisture content was maximum as 82% and in September minimum as 78.1%. Crude protein was in the range of 12.3-16.4%, crude lipid the average was 1.5%, crude ash on the average was 1.4%. The abundant fatty acids in geoduck muscle oil were $C_{16}$ : 0, $C_{16}$ : 1, $C_{18}$ : 0, $C_{18}$ : 1, $C_{20}$ : 5, and $C_{22}$ : 6 acids. During storage at $-20^{\circ}C$, content of unsaturated fatty acid such as eicosapentaenoic acid (EPA, $C_{20}$ : 5) and docosahexaenoic acid (DHA, $C_{22}$ : 6)in raw geoduck muscle decreased somewhat and the raw geoduck was slightly oxidized. Trimethylamine (TMA), volatile basic nitrogen (VBN)and $NH_2$-N of raw muscle increased compared to blanched muscle. Trimethylamine oxide (TMAO) was slightly decreased during the storage period. The muscle protein was approximately composed of 37% sarcoplasmic, 29% myofibrillar, 22% alkali soluble, and 12% stroma protein. Among several proteins, myofibrillar protein content decreased mostly, while the alkali-soluble and stroma protein content increased slightly during storage at $-20^{\circ}C$.

• Journal of Wetlands Research
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• v.25 no.1
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• pp.35-47
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• 2023

Korean facility horticulture and hydroponic cultivation methods increase, requiring the management of waste water generated. In this study, the amount of fertilizer contained in the discharged waste liquid was determined. By evaluating this as a price, it was suggested to reduce water treatment costs and recycle fertilizer components. It was evaluated based on the results of major water quality analysis of waste liquid by crop, such as tomatoes, paprika, cucumbers, and strawberries, and in the case of P component, it was analyzed by converting it to the amount of phosphoric acid (P₂O₅). The amount of nitrogen (N) can be calculated by discharging 1,145.90kg·ha^-1 of tomatoes, 920.43kg·ha^-1 of paprika, 804.16kg·ha^-1 of cucumbers, 405.83kg·ha^-1 of strawberries, and the fertilizer content of P₂O₅ is 830.65kg·ha^-1 of paprika, 622.32kg·ha^-1 of tomatoes, 477.67kg·ha^-1 of cucumbers. In addition, trace elements such as potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn) were also analyzed to be emitted. The price per kg of each item calculated by averaging the price of fertilizer sold on the market can be evaluated as KRW, N 860.7, P 2,378.2, K 2,121.7, Ca 981.2, Mg 1,036.3, Fe 126,076.9, Mn 62,322.1, Zn 15,825.0, Cu 31,362.0, B 4,238.0, Mo 149,041.7. The annual fertilizer loss amount for each crop was calculated by comprehensively considering the price per kg calculated based on the market price of fertilizer, the concentration of waste by crop analyzed earlier, and the average annual emission of hydroponic cultivation. As a result of the analysis, the average of the four hydroponic crops was 5,475,361.1 won in fertilizer ingredients, with tomatoes valued at 6,995,622.3 won, paprika valued at 7,384,923.8 won, cucumbers valued at 5,091,607.9 won, and strawberries valued at 2,429,290.6 won. It was expected that if hydroponic drainage is managed through self-treatment or threshing before discharge rather than by leaking it into a river and treating it as a pollutant, it can be a valuable reusable fertilizer ingredient along with reducing water treatment costs.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.31-40
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• 2003

A research has been done for growing characteristics of Korean ginseng in Geumsan of Chungnam Province. It had been made to determine the transitional element concentrations of the rocks, divided by biotitic granite(GR) and phyllite(PH). The physical and chemical properties of their weathering soils and ginseng nursery soils were analyzed. The texture in the GR weathering and ginseng nursery soils were sandy clay, and the texture of the PH weathering and ginseng nursery soils were heavy or silty clay. The bulk densities of the GR and PH weathering soils were $1.21{\sim}1.32g/cm^3$ and $1.26{\sim}1.38g/cm^3$, respectively. Also, the bulk densities of the GR and PH ginseng nursery soils were $1.02{\sim}1.10g/cm^3$, respectively. The pH (4.80) of the GR weathering soil were lower than the pH of the PH(5.34) weathering soil. The pH in the 2 year and 4 year-ginseng nursery soil of the GR were 4.39 and 4.40. In addition, those of the PH were 5.24 and 5.34, respectively. The difference in pH of the two nursery soils could be from the pH difference between the two parent materials. The organic matter contents of the GR weathering soils(0.24%) were higher than those of the PH(1.02%) weathering soils. The organic matter of the 2 and 4 year-ginseng GR nursery soils were 0.87% and 1.52%, and of the PH nursery soils were 2.06% and 2.96%, respectively. The total nitrogen contents of the GR weathering soils were 259.43ppm and of the PH weathering soils were 657.22ppm. Those of 2 and 4 year-ginseng GR nursery soils were 588.04ppm and 657.22ppm and those of the PH nursery soils were 1037.72ppm and 1227.96ppm, respectively. The nitrate and ammonium contents of the GR weathering soils were the extremely small, and those of the PH weathering soils were 6.7ppm and 9.94ppm. Those of 2 year-ginseng GR nursery soils(223.09ppm and 26.96ppm) were higher than those of PH(19.46ppm and 8.23ppm) nursery soils. And those of 2 year-ginseng PH nursery soils(14.22ppm and 16.84ppm) were lower than those of PH(306.93ppm, 34.21ppm) nursery soils. The difference was due to fertilizer types and more deposits of nitrate after oxidation of ammonium. The phosphate contents of the GR and PH weathering soils were 14.41ppm and 38.60ppm. Those of GR 2 and 4 year-ginseng nursery soils were 46.89ppm and 102.44ppm and those of the PH nursery soils were 147.04ppm and 38.60ppm. The cation exchange capacities of the GR weathering soils were 12.34me/100g and those of the PH weathering soils were 15.40me/100g. Those of 2 and 4 year-ginseng GR nursery soils were 15.80me/100g and 7.70me/100g and those of PH nursery soils were 12.14me/100g and 12.83me/100g. All of exchangeable cation($K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$) contents in the nursery soils were higher than those in the weathering soils. The $SO_4{^2-}$ contents of the weathering soils in both of the GR(5.98ppm) and PH(9.94ppm) were higher than those of the GR and PH ginseng nursery soils. The $Cl^-$) contents of the GR and PH weathering soils were a very small and those of the nursery soils(2-yr GR: 39.06ppm, 4-yr GR: 273.43ppm, 2-yr PH: 66.41ppm, 4-yr PH: 406.24ppm) were high because of fertilizer inputs.

• The Korean Journal of Mycology
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• v.7 no.2
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• pp.91-116
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• 1979

This paper is to investigate the standing crops and microfungal flora in soil in Phyllostachys reticulata forests in both the Yesan area (A) and the Kwangsan area (B). The stand density of the bamboo revealed 17,250 shoots per ha in area A, and in area B 14,780 shoots which were 16.1% less in number than area A. In respect to the environmental factors between the two areas, the mean temperature during the growth period was $1.5{\sim}2^{\circ}C$ higher in area B than in area A, soil tempeature also was $1{\sim}2^{\circ}C$ higher in area B, and the total quantities of nitrogen, phosphoric acid and organic compounds contained in the soil of area B were also slightly higher than those of area A. In area B the quantities of dried leaf matter, humus, and vegetation in the bamboo forest were also larger than in area A. In addition, five more species of microfungi which playa role in the decomposition of the various organic materials in the bamboo forests were identified in area B: Mortierella elongata, Mucor circinelloides, Aspergillus japonicus, Penicillium waksmani and Trichoderma lignorum. The atmospheric temperature in the inner portions of the bamboo forests was lower than the outside temperature, but the humidity was higher. The rates of relative illuminance were measured in area A at 4.19%, and in area B at 2.7%. These values revealed that the photosynthetic acitivity in the lower part of the bamboo was lost but it was considered that lower illuminance increased the microfungal activities in the vicinity of the surface soil. Since the productive structure of the bamboo showed that the maximum amount of photosynthesis was located in the upper portion of the bamboo in area B, it was considered to be an effective structure in maintaining the high productivity of the bamboo. The allometric relation between $D^2H$ and dry weight of stems(Ws), branches(Wb) and leaves(Wl) of the bamboo in area A were appoximated by log Ws=0.5262 log $D^2H$+1.9546; log Wb=0.6288 log $D^2H$+1.5723; log Wl=0.5181 log $D^2H$+1.8732, and those of the bamboo in area B were approximated by log Ws=0.5433 log $D^2H$+1.8610; log Wb=0.1630 log $D^2H$+2.3475; log Wl=0.4509 log $D^2H$+2.0041. From the above, the standing crops in area A were measured thus: Ws was 1,128. 83kg; Wb, 689.05kg; Wl, 926.69kg and Wl, 2,744.57kg per 10a. In area B, Ws was 1,206. 66kg; Wb, 679.92kg; Wl, 1,112.51kg and Wt, 2.999kg per l0a. Significant differences from the result of t-test were for $D^2H$ Ws, Wl and Wt between areas A and B. But no significant difference was found for Wb. In order to record as completely as possible the microfungal flora of the areas, every possible means was tried, and 158 strains of fungi were isolated, and of these, the microfungi of 55 species were identified. The dominant species were Trichoderma viride, Penicillium janthinellum, P. commune, Aspergillus oryzae, A. niger, A. gigantus, A. fumigatus, Mortierella ramaniana, var. anguliFPora, Mucor hiemalis and Zygorhynchus moelleri. According to the above results, it was revealed that optimum soil, the increases of soil materials, more species of soil microfungi, and the atmospheric temperature during the growth period have made the bamboo flourish and bring more species and larger quantities of vegetation in the bamboo forests. The correlation between the standing crops and environmental factors in the bamboo forest is considered to be a complicated relationship of all the factors, but the stand density is thought to be the most important factor involved.