• Korean Journal of Environment and Ecology
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• v.6 no.1
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• pp.1-8
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• 1992

Artificial acid rain (pH 3.0, 4.0 and 5.0) was treated on the seeded pots of 4 species to examine its effects on germination, leaf injury and seedling growth. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water (pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots three times per week. About 5mm of artificial acid rain was treated each time from early April to early October, 1991. Germination, seedling establishment, leaf injury, soil acidity and seedling growth were measured and compared among the treatments. The results were summarized as follows; 1. Germination and seedling establishment rate of Pinus thunbergiana was highest on the pH 4.0 pot whereas that of Picea abies was highest on the pH 3.0 pot. Those of Pinus densiflora and Abies holophylla were not significantly differed among the treatments. 2. The differences in seedling height of all species were not significantly differed among the treatments. 3. Seedling dry weight of Pinus densiflora differed significantly among the treatments. but that of Pinus thunbergiana did not differ. 4. With decrease of pH value of artificial acid rain. the number of injured needle and injured individual tended to be increased. 5. The differences of soil acidity were significant among the treatments for all species.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.2
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• pp.109-112
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• 1987

This experiment was to study the effects of soil compaction and artificial pore space on the shoot density of tall fescue (Festuca arundinacea Schreb.). Tall fescue subjected to compaction treatments with control, 10, 20 and 40 kg power roller, used for two times bi-weekly during six months. Artificial pore space treatments were control, 13.5, 37.5 and 84.5% at 0-lOcm depth, respectively. 1. Soil compaction increased soil hardness and soil bulk density.2. Compaction level of lOkg (soil hardness 2.5kg/$cm^3$) showed the highest shoot density than that of other treatments. 3. Artificial pore space was positive significant correlated (p<0.01) with shoot density. 4. When over the 37.5% of total pore space could be mainternance for high shoot density after the soil compacted.

• Journal of Life Science
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• v.29 no.2
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• pp.272-278
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• 2019

The silkworm performs sexual reproduction for the production of its healthy offsprings from generations to generations. Parthenogenesis in the silkworm, Bombyx mori acquires immense use in the development of outstanding homozygouse lines with higher viability, hybrid vigour, combining ability and less phenotypic variability, and it can serve as a powerful tool in controlling sex of the offsprings as well as a useful tool in selection of breeding schemes. However, naturally occuring parthenogenesis in silkworm could not be found so far. Fortunately, artificial induction of parthenogenesis is possible in silkworm. So, it is very important to find out novel methods for induction of parthenogenesis. We investigated to attempt to get a novel parthenogenetic method. Accordingly, parthenogenetic studies on between unfertilized in vivo ovarian eggs of live silkworm moth(novel) and unfertilized in vitro ovarian eggs(conventional) taken out from live silkworm moth were investigated by hot water ($46^{\circ}C$), hot air ($46^{\circ}C$) and low temperature ($0^{\circ}C$ and $-20^{\circ}C$) treatments. The best ratio of parthenogenetic eggs was obtained with in vivo ovarian eggs of live silkworm moth rather than with in vitro ovarian eggs taken out from live silkworm moth in all the treatments. The optimum exposure time absolutely depended upon the temperatures of treatments and the forms of in vivo or in vitro ovarian eggs. From these results, we expect that in vivo artificial parthenogenetic treatments on live silkworm moth will be useful for the higher induction of parthenogenesis in the silkworm, B. mori.

• Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.336-343
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• 2023

This study aimed to know the response of deep-sea squid Sthenoteuthis oualaniensis to the light colors of the artificial bait. This experiment used the commercial artificial flashlight baits commonly sold in the fishing shop. The bait has several different light color combinations. The light colors were modified into several light colors by inactivating certain colors and used as treatments. The study is expected to be able to find flashlight bait's most effective color for squid fishing. We applied red-green, green, blue, and commercial bait lights in this study. Each treatment has 3 replications. The effect was expressed as the amount of squid caught. Data were analyzed by one-way analysis of variance. Results showed a significant effect on the number of squid catches. There was significantly different squid catches among the treatments. It indicates that this artificial flashlight bait could be developed to maximize squid catches. This finding can be used for the local fishermen's income and the squid fisheries development.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.987-996
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• 2003

This study was conducted to determine the effects of the artificial culture medium of wild-ginsengs on in vitro fermentation characteristics. NH$_3$-N concentration was showed the highest in 3% WGM treatment among all treatments and control. In addition, microbial protein synthesis was significantly different in all treatments throughout the incubation time, and WGM 3% treatment was the highest at the 9 h incubation(P〈0.05). Protozoa numbers within rumen were decreased in all WGM treatments at 9 h incubation time, whereas WGM 3% treatment was always decreased throughout the incubation(P〈0.05). NDF and ADF digestibility were proportionally increased as the incubation time in both control and treatments. NDF digestibility showed no significantly difference between control and the 3% treatment, and ADF digestibility was similar in all. Total volatile fatty acid(VFA) concentrations of WGM treatments without 5% were significantly higher than control (P〈0.05). No differences were observed in total VFA, acetate, propionate and butyrate concentration among the WGM treatments. Acetate/Propionate ratio of WGM treatments was higher than control after 12 h incubation(P〈0.05). As a result of the artificial culture medium of wild-ginseng on rumen fermentation characteristics in vitro, microbial protein synthesis of WGM treatment was higher than control, and WGM 3% was the highest in all treatments(P〈0.05). The effect of saponin in artificial culture medium of wild-ginseng tended to decrease NH$_3$-N concentration, while it increases the microbial synthesis in early incubation. Therefore, artificial cultures medium of wild-ginseng can increase utilization of feed by microbial and anti-protozoal effects of saponin, which may enhance microbial synthesis capacity in early fermentation period in rumen.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.92-94
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• 2001

An experiment was conducted to compare the dietary supplemental influence of artificial zeolite produced from fly ash and natural zeolite on performance and physiological related factor of broiler chicks for five weeks. Diets contained CP 21.5, 19% and ME 3,100, 3,100kcal/kg for starting and finishing period. Three hundred twenty chicks were replaced into five treatments with four replicates. Control, 1.5 and 3.0% artificial(AZ) or natural zeolite(NZ) were supplemented to the basal diets, respectively. Weight gain, feed intake and feed conversion were weekly examined. Blood cholesterol, intestinal microflora, nutrients availability were measured at the end of experiment. Weight gain of chicks fed NZ tended to increase, but was not statistically different. However, the birds of fed 3.0% AZ showed significant decrement of weight gain compared to that of control(P<0.05). Feed intake was no difference in all treatments. Feed conversion was significantly improved in 3.0% NZ treatment relative to that of 3.0% AZ(P<0.05). There were no consistency in intestinal microbes between control and supplemental groups. Blood cholesterol was significantly lower in 3.0% NZ treatments than other treatments(P<0.05). Crude fiber digestibility of birds fed 3.0% NZ was significantly improved compared to that .of other treatments(P<0.05). As the results, artificial zeolite showed no detrimental effect in less than 1.5% addition on performance of broiler chicks.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.237-245
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• 1991

Artificial acid rain (pH 3.0, 4.0 and 5.0) was treated on thd seeds of 5 coniferous species to examine its effects on germination and seedling growth. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water(pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots three times per week. About 5mm of artificial acid rain was treated each time from early April to early October, 1990. Germination, seedling establishment and seedling growth were measured and compared among the treatments. The results were summarized as follows ; 1. Germination, seedling establishment rate of Larix leptolepis and Picea koraiensis were highest on the pH 5.0 plot whereeas those of Abies holophylla and Cryptomeria japonica were highest on the control plot, and those of Abies koreana showed the highest value on the pH 3.0 plot. 2. The differences in seedling height growth of Larix leptolepis was signif- icant at 1% level among the treatment levels of acid rain, whereas those of other species were not significant, Height of Larix leptolepis, Abies koreana and Picea koraiensis were highest on the pH 4.0 plot, and that of Abies holuphylla and Cryptomeria japonica were highest on the pH 5.0 plot. 3. Seedling dry weight of Larix leptolepis and Abies holophylla differed significantly at 1% level among the treatments, but those of other species did not differ. Highest seedling dry weight of Larix leptolepis and Abies koreana were observed on the pH 4.0 plot, and that of Abies holophylla and Cryptomeria japonica did on the pH 3.0 plot, and that of Picea koraiensis did on the control plot. 4. With decrease of pH value of artificial acid rain, the number of injured needle and injured individual tended to be increased, obviously. 5. The differences of soil acidity were highly significant among the treatments for all species.

• KIEE International Transactions on Electrophysics and Applications
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• v.12C no.4
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• pp.214-219
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• 2002

The influence of ultraviolet (UV) irradiation and corona on the surface degradation of high temperature vulcanized (HTV) silicone rubber used for outdoor insulation through measuring surface voltage decay after corona charging, surface resistivity, contact angle and X-ray photoelectron spectroscopy (XPS) analysis was studied. The surface resistivity calculated by the surface voltage decay was compared with a value directly obtained from the three electrode method having the guard ring electrode. A good agreement between the two methods for surface resistivity was obtained. UV treated specimens showed the slower decrease of surface voltage decay, while the corona exposed specimens showed a dramatically faster decrease. Although both artificial treatments cause the same oxidative products, which was confirmed with XPS, we could distinguish the difference between the reactions of the two treatments by monitoring the surface voltage decay on corona-charged specimen. In addition, we could derive the specific surface states of the silicone rubber treated by accelerated artificial aging factors and the degradation process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.8
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• pp.678-686
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• 2002

This paper presents the effects of accumulation of surface charges on hydrophobic level and the changes of surface potential decay with various artificial environment treatments on high temperature vulcanized (HTV) silicone rubber used for outdoor insulating material. For this study, the charging apparatus by corona discharge, in which grid electrode was installed between the main corona and ground electrode, was used. From this study, it was found that the accumulation of surface charges above a critical surface potential on silicone insulating materials could lead to the temporary loss of surface hydrophobicity. In addition, corona stress and water absorption stress increase the decay rate of surface charges of HTV silicone rubber, while ultraviolet (UV) stress causes longer decay time. We could conclude that the effects of surface charges on hydrophobicity level and the changes of surface state by various artificial treatments were found through a trend of surface potential decay.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.1-10
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• 1999

In this paper, we have investigated the effects of the environmental factors on Low Molecular Weight (LMW) silicone fluid contents existing in high temperature vulcanized (HTV) silicone rubber sample, using dipping method and contact angle, current measurement. Artificial treatments such as immersion in water, elevated temperature, UV irradiation and dry band arcing under salt-fog condition are selected as the environmental factors. This results will be helpful to investigate the degradation with time and to expect a life time, because the LMW silicone content, which is important to recovery the hydrophobicity of silicone rubber surface, show different results by each environmental factors.