• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.758-763
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• 2014

Soil microbial fuel cells (SMFC) have gained a great attention as an eco-friendly technology that can simultaneously generate electricity and treat organic pollutants from the contaminated soil. We evaluated the effect of electrode spacing and size on the performance of SMFC treating soil contaminated with organic pollutants. Maximum power density decreased with increase in electrode distance or decrease in electrode size, likely due to higher internal resistance. The maximum voltage and power density decreased from 326 mV and $19.5mW/m^2$ with 4 cm of electrode distance to 222 mV and $5.9mW/m^2$ with 9 cm of electrode distance. In case of electrode size test, the maximum voltage and power density generated was 291 mV, $0.34mW/m^3$ when both of anode and cathode area were $64cm^2$ with 4 cm of electrode distance. The maximum voltage decreased by 19~29% when the anode area decreased to $16cm^2$ while only 3~12% of voltage decreased with cathode area decrease. The maximum power density decreased by 49~68% with decreasing anode size, and by 29~47% with decreasing cathode size. These results showed that the anode area had more significant effects than the cathode area on the power generation of SMFC which has a high internal resistance due to a coexistence of soil and wastewater in the reactor.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.689-698
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• 2007

This study aims to estimate the genetic parameters for carcass traits on Hanwoo of breeding farmhouses using Animal Products Grading Service’s data of 428,812 cattle from 101 slaughterhouses nationwide from 2000 to 2005. Using carcass traits of carcass weight, eye muscle area, backfat thickness, marbling score, meat color and fat color that greatly influence Hanwoo's grade, the effects of carcass year, carcass season, sex and carcass region were estimated. Based upon carcass traits of carcass weight, eye muscle area, backfat thickness, marbling score and meat color that greatly influence Hanwoo’s grade, the heritabilities and genetic parameters were estimated of 17,578 Hanwoo slaughtered in 2005 with existing herdbook, where EM-REML algorithm was used in estimating genetic parameters. The mean and standard deviation of each carcass trait are 321.42±53.62kg, 76.25±10.43cm2, 9.96± 4.14mm, 3.75±2.00, 4.83±0.48 and 2.99±0.40, for carcass weight, eye muscle area, backfat thickness, marbling score, meat color and fat color, respectively. As a result of analysis on the effects of carcass year, the carcass weight, backfat thickness and meat color came out highest as 359.40±0.181, 9.82±0.017 and 4.90±0.002, respectively in 2004. As a result of analysis on the effects of carcass season, the carcass weight and eye muscle area came out highest as 345.88±0.144 and 79.57±0.033 respectively in spring, and the backfat thickness was highest as 8.78±0.013 in winter, and the meat color and fat color slightly came out higher as 4.88±0.002 and 2.96±0.001 in fall, while the marbling score was highest as 3.29±0.006 in summer. The results of the analysis on the effects of sex indicated that the backfat thickness and fat color were highest as 10.53±0.010 and 3.07±0.001 in cow, the carcass weight came out highest in Hanwoo steer as 368.03±0.068kg, the eye muscle area were highest as 82.96±0.042 in bull, and the marbling score was highest as 4.19±0.007 in steer, and the meat color was highest as 4.89±0.001 in cow. Regarding the results of analysis on the effects of carcass region, the carcass weight, eye muscle area,

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.104-113
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• 1993

The experiment was conducted in 1992 to find out the approach to the development of prediction model of weed population in paddy fields. The weed seeds of 88% over were separated from the soil by using $K_2CO_3$ 50% solution with specific gravity 1.34. The weed seeds which were floated on the solution due to the difference of specific gravity between soil particles and the seeds were effectively withdrawn by using a vaccum pump attached with an aspirator. The seeds withdrawn together with solution were taken by filtering with a nylon net of $0.31{\times}0.16mm$ mesh. The pressing method was more efficient and practical for the viability test of weed seeds separated from the soil compared with the germination test and the TTC test. For the prediction of weed population by the number of weed seedlings emerged at the sampled soil, the sampling method of 0-10cm deep at 5-6 sites per field was applicable. At the prediction method by the number of seedlings emerged, the smaller the seed sizes, the lower the prediction coefficients of weed species. It was considered that the prediction method by the number of seedlings emerged was more practical than the prediction method by the number of seeds separated from sampled soil, in relation to similarities to weed population, time and expenses required for examining, technical difficulties and applicability of weed species.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.756-763
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• 2013

Mechanical hair removal of carrot seed causes seed injuries and suppresses the germination in carrot cultivation. This study was performed to develop molecular markers for breeding high quality cultivars with short-hair seed. To meet this objective, random amplified polymorphic DNA (RAPD)-sequence characterized amplified region (SCAR) markers specifically linked to seed-hair characteristic were identified using CT-SMR 616 OP 389-1 line with short-haired seed and CT-SMR 616 OP 616-33 line with long-haired seed, bred by self-pollination for 6 years from 2008 to 2013, as parents. After seed hair lengths of these lines were analyzed using microscope, next generations were advanced and compared with the molecular markers polymorphism. From RAPD analysis using fixed lines in 2011, twelve RAPD primers showing polymorphic bands specific between the two lines were identified from 80 random primers. To develop RAPD-SACR marker, SCAR primers were designed based on sequence analysis of these specific RAPD bands and more than three combinations of primers were tested. As a result, it was found that the $SCA2_{1.2}$ amplified single polymorphic band from short-haired seed line. To confirm this result, $SCA2_{1.2}$ marker was retested by applying to the 2012 and 2013 progenies. Finally, it was concluded that the developed $SCA2_{1.2}$ marker distinguished short-haired line from long-haired seed line. Therefore, SCAR marker, $SCA2_{1.2}$ is expected to be utilized for breeding of the short-haired seed cultivars.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.782-789
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• 2013

Carrot (Daucus carota L. var. sativa) is one of the most widely used crops in the world and is nutritionally important crop. However, seed-hair which is generated in epidermal cell of seeds causes the difficulty of the seedling process, because of the seed germination and absorption inhibitions. For these reasons, carrot seeds are commercialized after mechanical hair removal process. However, in this process, various damage and seed loss occur and breeding of hairless-seed carrot cultivar is needed to overcome these various weaknesses and additional seed production costs. In this study, cDNA libraries using 2 combinations, which were composed of short-hair seed CT-ATR 615 OP 666-13 & long-hair seed CT-ATR 615 OP 671-9, and short-hair seed CT-SMR 616 OP 659-1 & long-hair seed CT-SMR 616 OP 677-14, were constructed and EST sequences of each individuals were analyzed to reveal carrot seed-hair characteristics. Firstly, analyzed EST sequences were classified into FunCat functional categories. As a result, significant differences have been identified in metabolism category, protein folding and stabilization, protein binding, C-compound binding category from both of two combinations. Secondly, several candidate EST sequences related to seed trichome differentiation and cellulose biosynthetic process were selected based on GO data of EST sequences. These differences based on FunCat categories and candidate EST obtained by GO data analysis are thought to be involved in the formation of carrot seed hair. Finally, 741 SSR sites and 33 SNP sites were identified from analyzed EST sequences of two combinations. Then we designed SNP and SSR primer sets to develop molecular markers. These molecular markers will be used for classification of carrot cultivars and study seed-hair characteristic.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.285-299
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• 1987

Timing and placement of fertilizer applications are two managerial means to improve the fertilizer use efficiency. The relative importance of these two means is determined by the application rate. With the realistic rate of N application recommended to the small farmers in the tropics, at present and in the near future, basal application in right manner, seems to be more important than split application at different times. In wetland rice soils, deep placement by whatever available means is desirable. But in the situations where perfect deep placement is very difficult to implement, the whole-layer application may be worth trying, until better methods become available. In rainfed uplands, N fertilizer application plans should be contingent upon the amount and distribution of rainfall: apply a less risky rate as subsurface banding near the crop rows to start with; then, depending upon the rainfall prospects in the season, apply or omit the additional dose. Because the patterns of crop response to N fertilizer can be significantly different between the research farms and farmers' fields, it seems imperative to have information on the patterns of crop response to N under farmers' management conditions, for the development of realistic fertilizer application recommendations. To enable the farmers to adopt improved fertilizer application technologies, it is essential to develop and make available to farmers convenient fertilizer applicators. Past experience with the improved fertilizer use technologies indicates that, in the long run, the development of fertilizers that are not only effective and convenient for farmers to use but also easy to produce without major modifications of existing fertilizer production systems is the ultimate solution to the problem of low N fertilizer use efficiency.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.37-45
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• 1970

The processing management forms of our country's filature factories in 1969 are summarized as follows. (1) About 80％ of total cocoon collection is made within 5 days involving peak day, and 10％ of cocoon collection is finished until 3 days before and after the peak day, (2) About 92％ of alive cocoons transported on unpaved road, and about 40％ of the cocoons purchased by all factories are loaded on trucks from common selling station which is far beyond 40km, therefore a new packing system of alive cocoons to drop the damage of cocoon qualities, should be taken. (3) 22％ of all factories in our. country have only low-temperature cocoon drying machine. Therefore the installment of hot-air cocoon drying machine is required urgently. (4) In view of cocoon qualities in our country, the grouping method of cocoon for reeling. taken by about 50％ of the factories at percent, which classify cocoons for reeling as high group (1,2,3,4 grades) and low group(5,6 grades), will have to be replaced by the method tat classify them high group (1,2 grades) middle group (3,4 grades), low group (5,6 grades). (5) The .ratio of cocoon assorting stood about 10％ in multi-ends reeling, about 15％ in automatic reeling, conclusively, the ratio of cocoon assorting for automatic reeling was higher tan that for multi-ends reeling. One person's ability for a day in cocoon assorting reaches to about 80-100kg. (6) Cocoon cooking condition requires the increase of the cooking time, the pressure and temperature used to be prolonged as much as the qualities of cocoons are material cocoon ior automatic and double cocoon machines are treated uncompletely. (7) Automatic silk reeling is being performed at 1-2$^{\circ}C$ lower in reeling water temperature and operated at about twice velocity. (8) The temperature and humidity of rereeling room stood at 25$^{\circ}C$, 67.2％ R.H and 32.3$^{\circ}C$, 51.9％ R.H of rereeling machine are showed, Average rereeling velocity is 233m/min and large reefs charged for one person are 7.5 reels and form of skein used in all factories is double skein. (9) About 73％ of water sources for filature used under-earth water. About 48％ of all filature factories in our country have not yet water purifying equipments. Installation of the equipment for these factories seems to be urgent, (10) Denier .balance, sizing reel, seriplane, are being used in most factories as self-inspection apparatus. (11) More than 90％ of the factories use the vacum tank in rereeling process and about 20％ of them use it in cocoon cooing process (12) Only 21％ of the factories use chemicals in filature process. About all them use "Seracol 100" in cocoon cooking process and "Seracol 500" in rereeling process, (13) Above survey results explain each all factories show large difference in the processing management. Therefore, it is believed that intercommunication through seminar or technical exchange will contribute to the production evaluation of cocoon in our filature industry.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.625-634
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• 2004

The objective of this experiment is to study the possibility of lactate dehydrogenase(LDH) enzyme to prevent lactate accumulation in the rumen, For understanding capacity of bacterial LDH in rumen environments, this study was conducted to explore the effects of temperature, pH, VFAs and metal ions on Lactobacillus sp. FFy111-1's LDH activity, and the LDH activation in rumen fluid accumulated lactate. The optimum pH and temperature of LDH were pH 7.5 and 40$^{\circ}C$, respectively. The LDH activity had a good thennostability at range from 30 to 50$^{\circ}C$. The highest pH stability of the enzyme was at ranges from pH 7.0 to 8.0 and the enzyme activities showed above 64% level of non-treated one at pH 6.0 and 6.5. The LDH was inactivated by VFAs treatments but was enhanced by metal ion treatments without NaCl and $CuSO_4$ Especially, the LDH activity was increased to 127% and 124% of its original activity by 2 mM of $BaCl_2$ and $MnSO_4$, addition, respectively. When the acidic rumen fluid was treated by LDH enzyme of Lactobacillus sp. FFy111-1, the lactate concentration in the rumen fluid was lower compared with non-treated rumen fluid(P<0.05). This lactate reduction was resulted from an action of LDH. It was proved by result of purified D,L-LDH addition that showed the lowest lactate concentration among the treatments(P<0.05). Although further investigation of microbial LDH and ruminal lactate is needed, these findings suggest that the bacterial LDH has the potential capability to decrease the lactate accumulated in an acidic rumen fluid. Also, screening of super LDH producing bacteria and technical development for improving enzyme activity in rumen environment are essential keys for practical application.

• Korean Journal of Environmental Agriculture
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• v.25 no.2
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• pp.138-146
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• 2006

To understand the status of water quality and work out a suitable countermeasures in Seonakdong watershed which has poor agro- environmental condition because of severe point and non-point source pollution by popularized city and near sea, we investigated the pollution sources and water quality from '03 and '05 and the result were mapped with GIS and RS for end-users's convenient comprehense and conjunction of water quality and geological data. The most degraded tributary was Hogeo stream which was affected directly by highly popularized Gimhae city, the main pollution source of the watershed. The pollution of tributaries in watershed increased the T-N of main body that reached over 4 mg/L during dry season. Pyeonggang stream and the lower part of main water way were suffered from high salt contents induced near sea and the EC value of those area were increased to 2.25 dS/m. The delivered loads of T-N and T-P were largest in Joman river as 56% and 61% of total delivered loads 1mm tributaries because of lots of stream flow. When Management mandate for irrigation water in Seonakdong river watershed was mapped for estimating integrated water quality as the basis of classification of EC and T-N contents in water, Hogeo and Shineo catchments were showed the requiring countermeasures none against nutrients hazard and Pyeonggang catchment was the vulnerable zone against nutrients and salts hazard. As the result, Seonakdong watershed had very various status of water quality by characteristics of catchments and countermeasures for improving water quality and crop productivity safely should changed depend on that.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.21-27
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• 2006

This study was conducted to determine the distribution of cat follicles among varying ages and produce oocytes from preantral follicles cultured in vitro. We used ovaries from 41 cats ranging in age from 0.3 to 5 years. Ovaries were obtained from cats undergoing routine ovariectomy at local veterinary clinics. As a prelude to in vitro culture of preantral follicles, the length and the width and the weight of ovaries among cats of varying ages were measured. Ovaries were fixed in 10% formalin, embedded in paraffin, cut into $3{\mu}m$-sections, mounted on slides and stained with hematoxylin and eosin. Follicles were evaluated at 200X and 400X magnification. Distribution of follicles among cats of varying ages were evaluated according to follicle classification: primordial, primary, transitional, preantral and antral follicles. Preantral follicles were isolated by the simple mechanical procedure. Each follicle was cultured in a well containing $100{\mu}l$ of medium 199 supplemented with 10% fetal bovine serum (FBS) or polyvinylalcohol (PVA) for 16 days. Follicle diameters were measured under inverted microscope every 4 days. The length, the width and the weight of ovaries were increased gradually according to ages but there was not significant difference among cats of varying ages. Majority of follicles were primordial follicles (84%) regardless of cat ages (p<0.05). Follicle diameter increased until 4 days of culture. However, period longer than 4 days of culture in vitro had a deleterious effect on follicle survival regardless of supplement (FBS or PVA). A few oocytes were collected from preantral follicles cultured in vitro. These basic reproductive techniques in domestic cats can be a useful tool to save endangered feline species.