• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.143-156
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• 2014

We reviewed investigation status on turbidity plume in the statement of marine environmental survey(2008 to 2012) associated with marine sand extraction projects. The survey statement from seven marine sand extraction sites (extraction area of Southern EEZ, extraction area of Western EEZ, relocation zone in the Western EEZ, sea area under jurisdiction of Taean-gun, sea area under jurisdiction of Ansan City, and two discrete sea areas under jurisdiction of Ongjin-gun) in the nearshore and offshore of Korea showed that in situ observations were carried out for the dispersion and transport of suspended sediments on two areas (One is a extraction area in the EEZs, the other is an area of coastal sites). However, sampling station and range have not been selected considering physical, geographical factors (tide, wave, stratification, water depth, etc.) and weather conditions (wind direction and velocity, fetch, duration, etc). Especially turbidity plumes originating from three sources, which include suspended sediments in overflow(or overspill) discharged from spillways and reject chutes of dredging vessel, and resuspended sediments from draghead at the seabed, may be transported to a far greater distance outside the boundary of the extraction site and have undesirable impacts on the marine environment and ecosystem. We address that behaviour of environmental pollutants such as suspended solids, nutrients, and metals should be extensively monitored and diagnosed during the dispersion and transport of the plume. Finally we suggest the necessity to supplement the current system of the sea area utilization consultation and establish the combined guidelines on marine sand extraction to collect basic data, to monitor cumulative effects, and to minimize environmental damages incurred by the aftermath of sand extraction.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.11-20
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• 2004

This pot experiment was conducted to investigate the effects of combined micronutrient application($T_1$;control, $T_2$; Fe, $T_3$; Fe＋Mn, $T_4$: Fe＋Mn＋Cu, $T_5$ ; Fe＋Mn＋Cu＋Zn, $T_6$ ; Fe＋Mn＋Cu＋Zn＋Mo, $T_7$ ;Fe＋Mn＋Cu＋Zn＋Mo＋B) on forage performance of pure and mixed cultures of orchardgrass and white clover. This 4th part was related to the changes in the contents of micronutrients(Fe, Mn, Cu, Zn, Mo, and B) in forages. The results obtained are summarized as follows: 1. General differences have been showed in the contents of micronutrients based on the treatments, forage species, pure/mixed culture, cutting order, and additional fertilization, especially N. Compared to pure culture, orchardgrass showed relatively high contents of Mn and Zn, and low contents of B and Fe in mixed culture. White clover, however, tended to be exactly opposed to the above trends. The contents of Cu and Mo did not show any differences between pure and mixed cultures. 2. In relative comparison, the $T_7$ influenced negatively on the contents of Cu, Zn, and Mo in orchardgrass. The $T_7$ also influenced negatively on the contents of Mo in white clover. However, the $T_7$ influenced positively on the contents of Mn in orchardgrass, and also influenced positively on the contents of Fe, Mn, and Cu in white clover. Because of the antagonism between Fe and Mn, the Fe contents in both forages were significantly decreased by the $T_3$. Under the various conditions, the differences among Fe contents tended to be more significant in white clover than in orchardgrass. 3. At the $T_6$ and $T_7$, the Mo contents in both forages tended to be relatively high. The Mo contents, however, were somewhat decreased by the $T_7$ 7/. The Mo-toxicity, which was caused by the high Mo-contents, tended to be diminished, and was likely to be prevented by the optimum B/Mo ratio and B application($T_7$ ).

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.4
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• pp.451-462
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• 2011

The purpose of this study was to investigate fungi and mycotoxin contamination of the rice straw bale silage in Korean. It was tested the 33 samples of rice straw round bale silage with various condition which fed cattle in the farm. The level of fungal contamination was $2.1{\times}10^6\;cfu\;g^{-1}$ in the average and $9.2{\times}10^8\;cfu\;g^{-1}$ in the maximum. The fungal contamination was detected in the all of normal samples which good condition of rice straw bale silage. When the fungi was isolate and identify, it was found 28 species and mycotoxin producing fungi were 8 species as following as Aspergillus flavus, Aspergillus fumigatus, Fusarium culmorum, Fusarium verticillioides, Penicillium carneum, Penicillium paneum, Penicillium roqueforti, Penicillium viridicatum. Specially, Penicillium paneum was found 42% of samples and Aspergillus sp. (A. flavus, A. fumigatus) are 21% of samples. In case of mycotoxin contamination, the 42% of samples are detected more than one kind of mycotoxin. Some samples are contaminated three kinds of mycotoxin. This study was not found aflatoxin ($B_1$, $B_2$, $G_1$, $G_2$) and fumonisin ($B_1$, $B_2$), but were detected the contamination of ochratoxin A (1.0~5.8 ug/kg), deoxynivalenol (DON, 156.0~776.7 ug/kg) and zearalenone (ZON, 38.0~750.0 ug/kg). Therefore, the above results show that rice straw round bale silage expose on hazard factors as mycotoxigenic fungi and mycotoxin contamination, and than need more research about mycotoxin in animal feed to protect animal and human healthy.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.4
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• pp.395-408
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• 2011

The study which it sees exclusions the copper and the zinc which contain in pig sludge, It study pig sludge resources fertilizer production which are rational, pig sludge resources fertilizers after seeding, silage corn it investigates growth characteristics and forage value, the result which investigates pig sludge resources fertilizers effectiveness with afterwards is same. With fertilizer ingredients in pig sludge chemical qualities, the content of the nitrogen and the phosphoric acid comes 4.4% to be 6.29%, pH 7.02 and content of the copper and the zinc which is a heavy metal which contains in pig sludge with 805 mg/kg and 1,704 mg/kg, it is a restrictive standard of the fertilizer, 300 mg/kg and 900 mg/kg it sees to be high, it manufactures citric acid 1 hydrate with the organic acid solution, heavy metals of pig sludge where it is a mixture ratio of the organic acid solution, it divides to 25%, 50%, 75% and 100% 4 kind levels, the result which measures the heavy metal exclusion ratio of the copper and the zinc, the mixture ratio of the organic acid solution to be many exclusion ratio of the copper and the zinc is showing a just interrelation, from organic acid solution 100% level content of pig sludge remains copper and zinc 330.03 mg/kg and 41.28 mg/kg, it shows the exclusion ratio of copper 59% zinc 97%. 'Cheonganok' growth characteristics with citric acid 1 hydrate, Treatment 2 and control growth characteristics etc, it exclusion the copper and the zinc it doesn't appear on significant difference statistically but, treatment 3 after only pig sludge in resources disposal where it seeding, growth characteristics of leaf area etc. is badness, it compares in control and treatment 2 the growth characteristics badness, it is appearing, it is caused by with disease and insects occurrence of $Ostrinia$ $furnacalis$ and brown spot, the damage was many. From forage value, Treatment 2 where it exclusion the heavy metal with the citric acid 1 hydrate with control it compares and there are not significant difference from crude protein and ADF and NDF contents etc., seeding only Pig Sludge in resources disposal treatment 3, it is caused by with $Ostrinia$ $furnacalis$ etc., trunk and aging of the leaf to be high ADF content is low. but from crude protein, the nitrogen ingredient which pig sludge has and interrelation it seemed and high numerical value were confirmed.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.115-126
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• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.707-716
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• 2001

This study was conducted four ecological survey of field mice of Mt. Chuisuh in Yangsan City, Kyungnam from June, 2000 to March, 2001 for the understanding of field mice damage to forest. The results are obtained as follows. 1. The species of field mice collected were Apodemus agrarius, Apodemus peninsulae and Eothenomys regulus, and Crocidura suaveolens of insectvore. 2. The total collecting rate were 8.1% collected 61 individuals of field mice from 758 trap. 3. The rate among the 61 field mice collected were 45.9% in Apodemus agrarius, 29.5% in Eothenomys regulus, 19.7% in Apodemus peninsulae, and 4.9% in Crocidura suaveolens. 4. The constitution of weight of field mice was 16-51.9g in Apodemus agrarius, 12-25.9g in Apodemus peninsulae, 16-45.9g in Eothenomys regulus, and 12-15.9g in Crocidura suaveolens. 5. The sex ratio of field mice was 48.0% : 52.0% in Apodemus agrarius, 50.0% : 50.0% in Apodemus peninsulae, 55.6% : 44.4% in Eothenomys regulus, and 66.7% : 33.3% in Crocidura suaveolens. 6. The average body lengh was 104.33mm in Eothenomys regulus, 96.04mm in Apodemus agrarius, 94.50mm in Apodemus peninsulae, and 76.33mm in Crocidura suaveolens. 7. The average tail lengh was 92.75mm in Apodemus peninsulae, 80.65mm in Apodemus agrarius, 41.0mm in Crocidura suaveolens, and 40.33mm in Eothenomys regulus. 8. The breeding period of field mice in Mt. Chuisuh presumes from about the early of March to end of October. Specially, The Eothenomys regulus was ascertained the breeding period in December, discovered first time in korea through this experimental study. 9. The average litter size of field mice was 4.5 in Apodemus agrarius, 4.7 in Apodemus peninsulae, and 3.4 in Eothenomys regulus.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.318-323
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• 2008

Nokwon, a new cultivar for vegetable soybean, was developed from the cross between Keunolkong and Hyangnam-1 and released in 2006. The pedigree of Nokwon, designated as Milyang 153 in 2003, was SS96425-2B-11-4-1-1-1. Nokwon, used as a vegetable soybean was characterized by dark green pod, large seed, very short plant height, and lodging resistance. Nokwon has determinate growth habit, white flowers, gray pubescence, oval leaf shape and brown pods at maturity. The mature seeds have a greenish yellow seed coat with brown hilum and yellow cotyledon. In Korea, Regional Yield Trials (RYT) for vegetable soybean from 2004 to 2006, Nokwon shows strong tolerance to soybean mosaic virus and lodging in fields. Fresh pods of Nokwon harvested at the beginning of August, and stem height was 11cm shorter than 45 cm of Hwaeomputkong. In the same tests, fresh pod of Nokwon (11.4 ton/ha) yielded 14% higher than Hwaeomputkong (10.0 ton/ha). Nokwon had 5.9 cm fresh pod length, 13.1 mm fresh pod width, 75.4 g seed weight per 100 green seed, 39.4% green seed protein content, and 17.3% green seed oil content.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.53-60
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• 1989

The results of the investigation on the effects of plant nutrio-physiological status and reemergence of sudden wilting in rice on the occurrence of sudden wilting were summarized as follows: 1. The occurrence of sudden wilting, degree of damage and occurring time in the investigated variety showed to concur with the results of the previous experiment. 2. Nitrogen and Potassium contents in leaves related an occurrence of sudden wilting at heading stage have a very high negative co-relation (the value is -0.9224 at Yushin and -0.8243 at Milyang 23). 3. Regarding the relation between occurrence of sudden wilting and root activity capacity at the late growth stage, the root activity capacity at productive growth stage showed higher than at reproductive growth stage, which is the same in the two varieties but Milyang 23 is higher than Yushin. It is confirmed that root activity capacity in the two varieties has become very low at reproductive growth stage. 4. The toot activity capacity in the field with potassium showed a small occurrence of sudden wilting and the root activity capacity in the field with no potassium showed a very high co-relation value (the value is 0.8947 at Yushin and 0.7301 at Milyang 23). 5. Regarding the relation between the occurrence of sudden wilting and water evaporation quantity, water evaporation quantity after the heading date has a more direct relation to sudden wilting than that which occurrs prior to the heading date. Water evaporation quantity is higher in the field with no potassium, low leaves and Yushin, than in the field with potassium high leaves and Milyang 23. 6. The starch content in culm of Yushin and Milyang 23 at ripening stage showed high value in proportion to potassium quantity, and the starch content is lower as internode is lower. However, in fourth internode, the starch content is greatly increased in the field with potassium contrasted to the field with no potassium.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.336-340
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• 2009

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October were investigated at Taean in 2007. Also, to estimate the contribution of ions on its acidity, ion composition characteristics and neutralization effects by cation ions were determined. The ion balance between cations and anions values showed high correlation. The mean values of pH and EC were 4.9 and $32.9{\mu}S\;cm^{-1}$, respectively. The EC of rainwater showed seasonal characteristic, which was $91.4{\mu}S\;cm^{-1}$ with relatively low rainfall compared with other monitoring periods. $Na^+$ was the main cation followed by $NH_4{^+}$ > $Ca^{2+}$ > $H^{+}$ > $Mg^{2+}$ > $K^+$. Among these ions, $Na^{+}$ and $NH_4{^+}$ covered over 70% of total cations. In the case of anion, the order was $SO_4{^{2-}}$ > $NO_3{^-}$ > $Cl^{-}$. The mean value of sulfate, which is main anion component in the samples was $152.1{\mu}eq\;L^{-1}$. Also, 90% of soluble sulfate in rainwater was $nss-SO_4{^{2-}}$(non-sea salt sulfate). With fractional acidity and theoretical acidity of rainwater samples, $NH_4{^+}$ and $Ca^{2+}$ contributed greatly in neutralizing the rain acidity.