• Journal of the Korean institute of surface engineering
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• v.17 no.4
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• pp.106-119
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• 1984

Brass was electrodeposited over the range of the current densities from 2 to 8 A/$dm^2$ in cyanide bath at 20 and 40$^{\circ}C$. The cathode overpotential increased and the cathode efficiency was decreased respectively with decreasing temperature, increasing current density and addition of organic substance. The perferred orientation of the deposits were associated with the cathode overpotential and the nucleation energy of lattice planes. The (111) preferred orientation developed at the low current density and low cathode overpotential (440-520mV). On the other hand, the (111)+(100) preferred orientation developed at higher cathode overpotential (528-680mV). The (111)+(100) preferred orientation developed over the whole range of overpotential in the cyanide solution with organic additive. The copper content of deposit decreased with increasing current density and decreasing temperature. The morphology of the deposits with no additive was the polygonal body type of structure and the structure of the cross section was columnar structure. The morphology of the deposits with additive, on the other hand, was fine crystallite type of structure. And the structure of the cross section of them was the finer granular structure.

• Korean Journal of Organic Agriculture
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• v.3 no.1
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• pp.71-78
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• 1994

This experiment was conducted to investigate the effects of mixed application of earthworm cast and N-fertilizer on dry matter(DM) yield in orchardgrass(Dactylis glomerate L.). Experimental plot were designed by a randomized block design with 3 replications of six different treatments-Control(0:0), 100% earthworm cast(0:100), 3 levels of mixed application(25:75:, 50:50, 75:25) of earthworm cast and N-fertilizer, and 100% N-fertilizer(100:0)based on content (%) of nitrogen. The experiment was carried out from March to October, 1993, on the forage experimental field of Kon-Kuk Univ. in Seoul. The results obtained are summarized as follows: 1. Annual dry matter yield was significantly increased according to increasing of N-fertilizer 2. Dry matter yield for each treatment as cutting time was passing was decreased. However, dry matter yield was slightly increased at 75%, 50%, and 25% mixed application of earthworm cast at the third cutting time than the second cutting time(p<0.05). 3. concerning each treatment per cutting time, dry matter yield was higher at 100% N fertilizer than the other treatments at the first, second, and fourth cutting time except the third cutting time only(p<0.05). And according to decreasing of mixing ratio of N fertilizer, dry matter yield was decreased, too. 4. Dry matter yield of 100% earthworm cast was significantly higher than control at the fourth cutting time(p<0.05).

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.161-164
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• 2011

Nitrogen fixation by legumes can be valuable sources for organic farming. This study was to investigate the effect of different legume mixtures on nitrogen fixation and transfer to grasses on spring paddy field. Three different mixtures were used (rye+hairy vetch, Italian ryegrass+crimson clover, oat+pea) in a randomized complete block design with three replications and sowed in pots with different sowing rate (5:5 rye:hairy vetch,7:3=Italian:crimson, 6:4=oat:pea) on early March. $(^{15}NH_4)SO_4$ solution at. 99.8 atom%$^{15}N$ was applied to the each pot at the rate of 2kg N $ha^{-1}$ on $16^{th}$ April. Forage were harvested at ground level in heading stage and separated into legume and grass. Total N content and $^{15}N$ value were determined using a continuous flow stable isotope ratio mass spectrometry. DM yield of rye+vetch, Italian+crimson and oat+pea were 6,607, 3,213 and 4,312kg/ha, respectively. Proportion of N from fixation was 0.73(rye+vetch), 0.42(Italian+crimson) and 0.93(oat+pea). The percentages of N transfer from legume to grass were from 61% to 24% in different method by treatments and -35% to 21% in isotope dilution method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.3
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• pp.271-279
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• 2021

Ultrasound-assisted extraction (UAE) conditions, including extraction time, extraction temperature, and ethanol concentration, were optimized to increase the total flavonoid content (TFC), tyrosinase inhibitory activity (TIA), and collagenase inhibitory activity (CIA) of Spirulina platensis through central composite design (CCD). For the optimization of the three dependent variables, a quadratic regression model was derived from 17 experimental sets for the simultaneous maximization of TFC, TIA, and CIA. The predicted optimal UAE conditions were 44.0 min of extraction time, 82.8℃ of extraction temperature, and 96.0% of ethanol concentration. Under these conditions, 0.93 mg QE/g DM of TFC, 81.9% of CIA, and 92.1% of TIA were predicted. The CCD-based UAE optimization enabled an increase in TFC, CIA, and TIA, thereby confirming that the S. platensis extract can be used in the development of a cosmetic material with skin whitening and anti-wrinkle effects.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.323-330
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• 2008

This study was carried out to evaluate the effect of application of cattle manure and chemical fertilizer on dry matter productivity and nutritive values of rye and hairy vetch according to two different sowing methods such as single or mixed-sowed cultivation. Dry matter and TDN yields for rye single culture, and rye and hairy vetch mixed culture were 7.2 and 4.0 ton/ha, and 8.0 and 4.4 ton/ha, respectively. They were significantly (p<0.05) higher than that (4.5 and 2.7 ton/ha) of hairy vetch single culture. Moreover, plots produced by mixed-sowing cultivation had a higher crude protein (CP) as 7.7% than that of only rye plot, and higher TDN and RFV as 55.8 and 79.4%, respectively. Within rye alone plots, completely cattle slurry application produced significantly higher annual DM and TDN yields (7.4 and 4.1 ton/ha) than those of P+K fertilization (7.2 and 3.9 ton/ha) as a chemical fertilizer and non-fertilizer (5.5 and 3.1 ton/ha). Cattle slurry application plot revealed 75.52 and 78.97% of N+P+K fertilization plot for annual DM and TDN, respectively. Within mixed-sowing cultivation with rye and hairy vetch, completely cattle slurry application produced 7.6 ton/ha DM and 4.5 ton/ha TDN, showing 79.50 and 86.77% of N+P+K fertilization plot, respectively. Furthermore, the CP content for cattle slurry plots was 8.5%, which was significantly (p<0.05) higher than those of other plots, and it was also highest in TDN (58.3%) and RFV (86). Overall, rye mixed-sowing with hairy vetch rather than rye alone sowing reduced DM yields, but leaded to enhancement of feed value and nutritive yields. And also, it would be expected that cattle slurry application in comparison with chemical fertilizers might result in reutilization of resources, improved forage quality and, extended harvest period by preventing feed value from rapidly deteriorating.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.116-120
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• 1991

Silage productivity of two sorghum hybrids. Pioneer(P) 931 and P 956, and green fodder productivity of a sorghum-sudangrass hybrid, P 988, were tested at four levels of seeding rates (1, 2, 3, and 4 kg/lOa). The 1st-cut of sorghum hybrids of P 931 and P 956 was made at milk ripe stage for silage on July 22 and 31, respectively and regrowth was harvested on Oct. 13. The 1st-and 2nd-cut of a sorghum-sudangrass hybrid were made at flag leaf emerging stage for green fodder on July 26 and Aug. 16 and 3rd-cut was harvested on Oct. 13. The results obtained are summarized as follows:1. Growth stage, culm length or plant height, and percent dry matter (DM) were similar among the seeding rates. Percent DM of sorghum hybrids ranged 26.9-31.2% regardless hybrids and t ~ m e of harvest. However, in the sorghum-sudangrass hybrid percent DM of the 1st-cut. 2nd-cut, and 3rd-cut ranged 10.0-10.7% 18.2-19.97% and 24.6-27.8% respectively.2. In sorghum hybrids crude(C) fiber content of P 931 was higher, but nitrogen free extract (NFE) was lower compared with those of P 956 and C. protein and C. fat were similar between two hybrids. However, C. protein and C. ash of sorghum hybrids were lower, but C. fiber and NFE were higher compared with those of a sorghum-sudangrass hybrid and C. fat was similar between two crops.3. Total DM yield was greater in the order of P 931>P 956>P 988. The optimum seeding rate for both silage yield of sorghum hybrids and green fodder of a sorghum-sudangrass hybrid was 2-4 kg/lOa. However, yield of the 1st-cut tended to increase as seeding rate increased.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.115-120
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• 2010

This study was carried out to determine the forage production and quality of Italian ryegrass (IRG) and forage barley sown in early spring in Suwon, 2009. The five treatments used in this experiment were IRG Kowinearly (early maturity), IRG Kowinmaster (medium maturity), Yuyeon barley, Kowinearly + Yuyeon mixture, and Kowinmaster + Yuyeon mixture. The lodging was observed in IRG, but no lodging was found IRG + barley mixtures. The heading date of Kowinearly and Kowinmaster were 16 May and 22 May, respectively, and that of barley was 13 May. The dry matter (DM) percentage at harvest was 22.2~27.6%. The forage quality among treatments were similar, but the crude protein (CP) content of IRG was higher than that of barley, and in vitro DM digestibility was a little low in Kowinmaster. The yields of DM, CP and digestible DM were high in Kowinearly + Yuyeon barley mixtures as a 13,816 kg, 1,384 kg and 10,387 kg per ha, respectively (p<0.05). In conclusion, the mixture cultivation of IRG and forage barley was very effective, because of preventing of IRG lodging, increasing of forage yield, and stable production of forages. The optimum harvest date for silage manufacture of IRG and barley sown in early spring was recommended early June instead of May.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.4
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• pp.317-324
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• 1999

This study was conducted to evaluate the dry matter yield and quality of mixture swards associated with Festulolium braunii(Festuca pratensis Huds. ${\times}$ Lolium multiflorum Lam.). The experiment was arranged in a randomized block design with four mixture types: A(control); orchardgrass(seeding rate 60%) + tall fescue 20% + Kentucky bluegrass 10% + white clover 10%, B; orchardgrass 60% + tall fescue 20% + Festulolium braunii 10% + white clover 10%, C; orchardgrass 60% + Festulolium braunii 20% + Kentucky bluegrass 10% + white clover 10%, and D; orchardgrass 30% + Festulolium braunii 30% + red clover 40%. This study was carried out from Sept. 1996 to Dec. 1998 at Chungnam National University. The DM yield of D mixture type was higher than that of other mixture types(P<0.05). Compared with A(control) mixture type, the DM yield of the B mixture type which substitutes Kentucky bluegrass with Festulolium braunii was higher, but the C mixture type which substitutes tall fescue with Festulolium braunii was lower than that of A(control) mixture type. The content of CP, NDF, ADF, hemi-cellulose and cellulose among mixture types shows no significant differdence. Howerever, the DMD was not significantly different among mixture types in 1997, but the DMD of C and D mixture type were significantly higher than those of other mixture types in 1998(P<0.05). On the otherhand, the yield of CP and DDM in D mixture types was higher than those of the other mixture types(P<0.05). In botanical composition, the Festulolium braunii percentage of B, C and D mixture type with mixed Festulolium braunii wasd highly maintained, especially D mixture type was ranging from 40% to 60% in experimental periods. Following the above result, It is the most favorable mixture method for Festulolium braunii to make use of top grass like orchardgrass + red clover. It is also recommened to substitute bottom grass like Kentucky bluegrass with Festulolium braunii rather than with tall fescue in A(control) mixture type.

• Journal of The Korean Society of Grassland and Forage Science
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• v.31 no.1
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• pp.39-46
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• 2011

This study was carried out to determine the forage yield, quality, and regrowth of Italian ryegrass (IRG) and barley sown on 2 March 2009 in Suwon. The five treatments were two IRG cultivars (Kowinearly with early maturity and Kowinmaster with medium maturity), one barley cultivar (Yuyeon), and two mixtures (Kowinearly + Yuyeon and Kowinmaster + Yuyeon). The first harvest date was 26 May, which was at late heading, heading and early dough stage of Kowinearly, Kowinmaster and barley, respectively. Regrowth yield was investigated on 29 June. The heading dates of Kowinearly and Kowinmaster were 16 May and 22 May, respectively, and that of barley was 13 May. The dry matter (DM) percentage were 13.0~18.4% at first harvest, and 22.5~24.8% at regrowth in all treatments. The forage yield of barley and Kowinmaster + Yuyeon mixture at first harvest was higher than that of IRG (p<0.05), but higher regrowth yield was observed in IRG, and then IRG + barley mixtures (p<0.05). The crude protein (CP) content and in vitro DM digestibility (IVDMD) of IRG at first harvest were 16.7~17.1% and 78.3~80.4%, respectively, which were higher than those of barley (CP 12.2% and IVDMD 72.6%) and IRG + barley mixtures. The total yields of DM, CP and digestible DM were high in Kowinmaster + Yuyeon mixture as 11,628 kg, 1,669 kg and 8,457 kg per ha, respectively. In conclusion, spring seeding of IRG + barley mixtures and/or barley were recommended when early harvest. Regrowth of IRG sown in early spring was vigorous. Mixture cultivation of IRG and barley was effective, because of forage yield and stable production, and harvest at June instead of May was desirable for forage productivity of spring sown IRG and barley.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.115-122
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• 2002

In this study, the effects of alfalfa hay included in different ratios of 60%(A), 50%(B), 40%(C) and 30%(D) for the diets of young weaned Korean native goats were investigated on feed intake, digestibilities of nutrients, nitrogen retention, average daily gain and feed efficiency. Crude protein contents of experimental diets were 18% in all treatments. The contents of ADF, NDF and crude ash were higher in A as 26.1, 37.0 and 9.0% compared to the lowest values in D of 20.3, 30.4 and 6.6%. However the contents of non-structural carbohydrates was in the opposite tendency. Daily feed intake (DM) was highest in A (414.4g) and B (417.7g) and significantly (p<0.05) lower in D(362.6g). Dry matter intake per metabolic basal weight (DM g/kg of $BW^{0.75}$ ) were highest in A(73.9g) and lowest in D(64.0g). Average daily gain and feed efficiencies were in the range of 33.3~48.7g and 8.1~13.4% respectively with no statistical differences, however with the increasing trends according to higher percent of roughage in the diets. Digestibilities of dry matter (DM), organic matter (OM), crude protein (CP), ADF, NBF, crude ash (CA) and non-structural carbohydrates (NSC) were in the tendency of becoming higher according to higher ratios of concentrate but becoming lower according to higher ratio of alfalfa hay in the diets fed to Korean native goats. Nitrogen retention was lowest in A (1.8g, 15.5%) and highest in D (2.7g, 25.7%). In overall, inclusion of 30~40% alfalfa hay as a roughage in the diets of weaned Korean native goats was superior to the higher rates of inclusion of alfalfa hay in aspects of average daily gain and feed efficiency. The fixed 18% of crude protein content in the diets was efficient for the growth of weaned goats.