• Korean Journal of Organic Agriculture
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• v.32 no.3
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• pp.277-288
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• 2024

The present study was conducted to investigate the effects of seaweeds on in vitro ruminal fermentation characteristics and methane gas production. Five seaweeds (Dictyota dichotoma, DD; Chrysymenia wrightii Yamada, CW; Codium fragile, CF; Sargassum fusiforme, SF; Gracilaria vermiculophylla, GV) were obtained from National Institute of Fisheries Science (NIFS) in South Korea. The ruminal fluids were collected from 3 rumen-cannulated Hanwoo steers (average 12-months-old). The buffered ruminal fluids (50 mL) were incubated with substrates (0.4 g of concentrate and 0.1 g of rice straw in dry matter basis) and seaweeds (5% of substrates) at 39℃ for 24 and 48 hours. The total gas and methane production of all treatments incubated for 24 hours were not affected by the seaweed. However, methane production (mL/g of digested dry matter) in the CW and CF treatments incubated for 48 hours was decreased compared to control (p<0.05). Additionally, the ruminal pH of all treatments incubated for 24 and 48 hours was lower than control (p<0.05). There was no signigicant difference in total VFA concentration at 24 hours of incubation, but it was higher in the CF treatment at 48 hours of incubation (p<0.05). The dry matter digestibility of all treatments incubated for 24 and 48 hours were not affected by the seaweed. In conclusion, Codium fragile reduced in vitro methane production without negative effects on rumen fermentation characteristics.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.39-46
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• 2015

Objective of this research was to investigate the influence of compositions and concentrations of fertilizer solutions on the vegetative growth and nutrient uptake of 'Seolhyang' strawberry. To achieve this, the solutions of acid fertilizer (AF), neutral fertilizer (NF), and basic fertilizer (BF) were prepared at concentrations of 100 or $200mg{\cdot}L^{-1}$ based on N and applied during the 100 days after transplanting. The changes in chemical properties of the soil solution were analysed every two weeks, and crop growth measurements as well as tissue analyses for mineral contents were conducted 100 days after fertilization. The growth was the highest in the treatments with BF, followed by those with NF and AF. The heaviest fresh and dry weights among treatments were 151.3 and 37.8 g, respectively, with BF $200mg{\cdot}L^{-1}$. In terms of tissue nutrient contents, the highest N, P and Na contents, of 3.08, 0.54, and 0.10%, respectively, were observed in the treatment with NF $200mg{\cdot}L^{-1}$. The highest K content was 2.83%, in the treatment with AF $200mg{\cdot}L^{-1}$, while the highest Ca and Mg were 0.98 and 0.42%, respectively, in BF $100mg{\cdot}L^{-1}$. The AF treatments had higher tissue Fe, Mn, Zn, and Cu contents compared to those of NF or BF when fertilizer concentrations were controlled to equal. During the 100 days after fertilization, the highest and lowest pH in soil solution of root media among all treatments tested were 6.67 in BF $100mg{\cdot}L^{-1}$ and 4.69 in AF $200mg{\cdot}L^{-1}$, respectively. The highest and lowest ECs were $5.132dS{\cdot}m^{-1}$ in BF $200mg{\cdot}L^{-1}$ and $1.448dS{\cdot}m^{-1}$ in BF $100mg{\cdot}L^{-1}$, respectively. For the concentrations of macronutrients in the soil solution of root media, the AF $200mg{\cdot}L^{-1}$ treatment gave the highest $NH_4$ concentrations followed by NF $200mg{\cdot}L^{-1}$ and AF $100mg{\cdot}L^{-1}$. The K concentrations in all treatments rose gradually after day 42 in all treatments. When fertilizer concentrations were controlled to equal, the highest Ca and Mg concentrations were observed in AF followed by NF and BF until day 84 in fertilization. The BF treatments produced the highest $NO_3$ concentrations, followed by NF and AF. The trends in the change of $PO_4$ concentration were similar in all treatments. The $SO_4$ concentrations were higher in treatments with AF than those with NF or BF until day 70 in fertilization. These results indicate that compositions of fertilizer solution should to be modified to contain more alkali nutrients when 'Seolhyang' strawberry is cultivated through inert media and nutri-culture systems.

• Applied Biological Chemistry
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• v.13 no.2
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• pp.111-129
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• 1970

As a series of studies on the nucleic acids and their related substances 210 samples were collected from 76 places such as farm soil, compost of heap, nuruk and meju to obtain microbial strains which produce 5'-phosphodiesterase. From these samples total of 758 strains were isolated by the use of dilution pour plate method. For all isolated strains primary screening of the productivity of RNA depolymerase was performed and useful strains with regard to 5'-phosphodiesterase productivities were identified. For these useful strains optimum condition, the effect of various compounds on the activity of 5'-phosphodiesterase, and the optimum condition for enzyme reaction were discussed. The quantitative of 5'-mononucleotides produced by the action of 5'-phosphodiesterase was performed using anion-exchange column chromatography and their identified was done by paper chromatography, thinlayer chromatography, ultra violet spectrophotometry, and characteristic color reaction using carbazole and schiff's reagent. (1) Penicillium citreo-viride PO 2-11 and Streptomyces aureus SOA 4-21 from soil were identified as a potent 5'-phosphodiesterase producing strains. (2) Optimum culture conditions for Penicillium citreo-viride PO 2-11 strain isolated were found to be pH 5.0 and $30^{\circ}C$, and the optimum conditions for enzyme action of 5'-phosphodiesterase were pH 4.2 and $60^{\circ}C$. Best carbon source for the production of 5'-phosphodiesterase was found to be sucrose and ammonium nitrate for nitrogen source. Addition of 0.01% corn steep liquor or yeast extract exhibited 20% increase in the amount of 5'-phosphodiesterase production compared to the control. 5'-phosphodiesterase produced by this strain was activated by $Mg^{++},\;Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by EDTA, citrate, $Cu^{++},\;CO^{++}$. 5'-phosphodiesterase produced 5'-mononucleotide from RNA at a rate of 65.81%, and among the 5'-mononucleotides accumulated 5'-GMP only was found to have flavorous and the strain was also found lack of 5'-AMP deaminase. Productivity of flavorous 5'-GMP was found to be 186.7mg per gram of RNA. (3) Optimum culture canditions for the isolated Streptomyces aureus SOA 4-21 strain were pH 7.0 and $28^{\circ}C$, and the optimum conditions for the action of 5'-phosphodiesterase were pH 7.3 and $50^{\circ}C$. The best carbon source for 5'-phosphodiesterase production was found to be glucose and that of nitrogen was asparagine. Addition of 0.01% yeast extract exhibited increased productivity of 5'-phosphodiesterase by 40% compared to the non-added control. 5'-phosphodiesterase produced by this strain was activated by $Ca^{++},\;Zn^{++},\;Mn^{++}$ and was inhibited by citrate, EDTA, $Cu^{++}$. It was also found that the strain produce 5'-AMP deaminase in addition to 5'-phosphodiesterase. For this reason although decomposition rate was 63.58% the accumulation of 5'-AMP, 5'-CMP, 5'-GMP and 5'-UMP occurred by the breakdown of RNA. In the course of these reaction 5'-AMP deaminase converted 60% of 5'-AMP thus produced into 5'-IMP and flavorous 5'-mono nucleotide production was significantly increased by this strain over the above mentioned one. Production rates were found to be 171.8mg per grain of RNA for 5'-IMP and 148.2mg per gram of RNA for 5'-GMP, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.651-658
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• 2009

Four multiparous lactating Holstein cows fitted with rumen cannulae were fed diets varying in the amount and source of rumen-degradable carbohydrates (starch vs. sucrose) to examine their effects on rumen fermentation, nitrogen metabolism and lactation performance. A $4{\times}4$ Latin square with four diets and four periods of 28 days each was employed. Corn starch and sucrose were added to diets and corn starch was replaced with sucrose at 0 (0 S), 2.5 (2.5 S), 5.0 (5.0 S) 7.5% (7.5 S) of diet dry matter in a total mixed ration (TMR) containing 60% concentrate and 40% forage (DM basis). Replacing corn starch with sucrose did not affect (p>0.05) ruminal pH which averaged 6.41, but the ruminal pH for 7.5 S decreased more rapidly at 2 h after morning feeding compared with other treatments. Sucrose reduced ($p{\leq}0.05$) ruminal $NH_3-N$ concentration (13.90 vs. 17.09 mg/dl) but did not affect peptide-N concentration. There was no dietary effect on total volatile fatty acids (110.53 mmol/L) or the acetate to propionate ratio (2.72). No differences (p>0.05) in molar proportion of most of the individual VFA were found among diets, except for the molar proportion of butyrate that was increased ($p{\leq}0.05$) with the inclusion of sucrose. Total branched chain volatile fatty acids tended to increase ($p{\geq}0.051$) for the control treatment (0 S) compared with the 7.5 S treatment. Dry matter intake, body weight changes and digestibility of DM, OM, CP, NDF and ADF were not affected by treatments. Sucrose inclusion in the total mixed ration did not affect milk yield, but increased milk fat and total solid percentage ($p{\leq}0.05$). Sucrose tended ($p{\geq}0.063$) to increase milk protein percentage (3.28 vs. 3.05) and reduced ($p{\leq}0.05$) milk urea nitrogen concentration (12.75 vs. 15.48 mg/dl), suggesting a more efficient utilization of the rapidly available nitrogen components in the diet and hence improving nitrogen metabolism in the rumen.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1705-1712
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• 2007

The effect of different tropical feed sources on rumen ecology, cellulolytic bacteria, feed intake and digestibility of beef cattle was investigated. Four fistulated, castrated male crossbred cattle were randomly allocated to a $4{\times}4$ Latin square design. The treatments were: T1) urea-treated (5%) rice straw (UTS); T2) cassava hay (CH); T3) fresh cassava foliage (FCF); T4) UTS:FCF (1:1 dry matter basis). Animals were fed concentrates at 0.3% of body weight on a DM basis and their respective diets on an ad libitum basis. The experimental period was 21 days. The results revealed that the use of UTS, CH, FCF and UTS:FCF as roughage sources could provide effective fiber and maintain an optimal range of ruminal pH and $NH_3-N$. Total viable and cellulolytic bacterial populations were enhanced (p<0.05) with UTS as the roughage source. Animals fed FCF had a higher rumen propionate production (p<0.05) with a lower cellulolytic bacteria count. Moreover, three predominant cellulolytic bacteria species, namely Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens, were found in all treatment groups. Roughage intake and total DM intake were highest with UTS (2.2 and 2.5% BW, respectively) as the roughage source (p<0.05). Nutrient intake in terms of organic matter intake (OMI) was similar in UTS, CH and UTS:FCF treatments (8.0, 6.8 and 8.7 kg/d, respectively), while crude protein intake (CPI) was enhanced in CH, FCF and UTS:FCF as compared to the UTS treatment (p<0.05). Digestion coefficients of DM and organic matter (OM) were similar among treatments, while the CP digestion coefficients were similar in CH, FCF and UTS:FCF treatments, but were higher (p<0.05) in CH than in UTS. CP and ADF digestible intakes (kg/d) were highest (p<0.05) on the CH and UTS treatments, respectively. It was also observed that feeding FCF as a full-feed resulted in ataxia as well as frequent urination; therefore, FCF should only be fed fresh as part of the feed or be fed wilted. Hence, combined use of FCF and UTS as well as CH and FCF were recommended.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.73-81
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• 2011

Six male crossbred (Thai Native${\times}$Anglo Nubian) goats, with an average initial weight of $22{\pm}2\;kg$, were randomly assigned according to a $3{\times}2$ factorial arrangement in a $6{\times}6$ Latin square design with a 21-d period to evaluate the effect of feeding rubber seed kernel (RSK) and palm kernel cake (PKC) in combination on nutrient utilization, rumen fermentation characteristics, and nitrogen utilization. The dietary treatments were as follows: i) concentrate containing 0% RSK and 20% PKC ($T_1$), ii) 0% RSK and 30% PKC ($T_2$), iii) 20% RSK and 20% PKC ($T_3$), iv) 20% RSK and 30% PKC ($T_4$), v) 30% RSK and 20% PKC ($T_5$), and vi) 30% RSK and 30% PKC ($T_6$). During the experiment, signal hay was given on an ad libitum basis as the roughage. It was found that RSK levels and PKC levels had no interaction effects on feed intake, apparent digestibility, $NH_3$-N, blood metabolites, VFA concentrations, and nitrogen utilization, but there were interactions between RSK levels and PKC levels with respect to total DMI (kg/d) and total VFA concentrations, and goats receiving 30% RSK had lower values (p<0.05) than those receiving 0 and 20% RSK, respectively. Feeding different PKC levels did not affect (p>0.05) feed intake, digestibility, rumen fermentation patterns, blood metabolites, and nitrogen utilization. However, increasing RSK levels (>20%) resulted in a slightly lower daily DMI (% BW and g/kg $BW^{0.75}$), apparent digestibility (NDF and ADF), total N intake, and N excretion than in goats fed on 0 and 20% RSK. BUN, blood glucose, and propionate were variable among treatment and were highest in 0% RSK with the 20% PKC fed group having values which were higher than those in other groups. However, there were no differences (p>0.05) among treatments with respect to N retention, PD output, and microbial N supply. Based on this study, RSK levels up to 20% and PKC at 20-30% in concentrate could be efficiently utilized for goats fed on signal hay.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.429-429
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• 2016

Organolead halide perovskite have attracted much attention over the past three years as the third generation photovoltaic due to simple fabrication process via solution process and their great photovoltaic properties. Many structures such as mesoporous scaffold, planar heterojunction or 1-D TiO2 or ZnO nanorod array structures have been studied to enhance performances. And the photovoltaic performances and carrier transport properties were studied depending on the cell structures and shape of perovskite film. For example, the perovskite cell based on TiO2/ZnO nanorod electron transport materials showed higher electron mobility than the mesoporous structured semiconductor layer due to 1-D direct pathway for electron transport. However, the reason for enhanced performance was not fully understood whether either the shape of perovskite or the structure of TiO2/ZnO nanorod scaffold play a dominant role. In this regard, for a clear understanding of the shape/structure of perovskite layer, we applied anodized aluminum oxide material which is good candidate as the inactive scaffold that does not influence the charge transport. We fabricated vertical one dimensional (1-D) nanostructured methylammonium lead mixed halide perovskite (CH3NH3PbI3-xClx) solar cell by infiltrating perovskite in the pore of anodized aluminum oxide (AAO). AAO template, one of the common nanostructured materials with one dimensional pore and controllable pore diameters, was successfully fabricated by anodizing and widening of the thermally evaporated Al film on the compact TiO2 layer. Using AAO as a scaffold for perovskite, we obtained 1-D shaped perovskite absorber, and over 15% photo conversion efficiency was obtained. I-V measurement, photoluminescence, impedance, and time-limited current collection were performed to determine vertically arrayed 1-D perovskite solar cells shaped in comparison with planar heterojunction and mesoporous alumina structured solar cells. Our findings lead to reveal the influence of the shape of perovskite layer on photoelectrical properties.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.341-341
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• 2016

The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1416-1423
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• 2016

This study was designed to investigate the effect of grape pomace powder (GPP), mangosteen peel powder (MPP) and monensin on feed intake, nutrients digestibility, microorganisms, rumen fermentation characteristic, microbial protein synthesis and nitrogen balance in dairy steers. Four, rumen fistulated dairy steers with initial body weight (BW) of $220{\pm}15kg$ were randomly assigned according to a $4{\times}4$ Latin square design to receive four treatments. The treatments were as follows: T1 = control, T2 = supplementation with monensin at 33 mg/kg diet, T3 = supplementation with GPP at 2% of dry matter intake, and T4 = supplementation with MPP at 30 g/kg diet. The steers were offered the concentrate diet at 0.2% BW and 3% urea treated rice straw (UTRS) was fed ad libitum. It was found that GPP supplemented group had higher UTRS intake and nutrient digestibility in terms of neutral detergent fiber and acid detergent fiber than those in control group (p<0.05). Ammonia nitrogen ($NH_3-N$) and blood urea-nitrogen concentration were higher in monensin, GPP and MPP supplemented groups (p<0.05). Total volatile fatty acids and propionate in the GPP group were higher than those in the control group (p<0.05) while acetate concentration, and acetate to propionate ratio were decreased (p<0.01) when steers were supplemented with GPP, monensin, and MPP, respectively. Moreover, protozoal populations in GPP, MPP, and monensin supplementation were significantly lower than those in the control group (p<0.05), while cellulolytic bacterial population was significantly higher in the control group (p<0.05). Nitrogen retention, microbial crude protein and efficiency of microbial nitrogen synthesis were found significantly higher in steers that received GPP (p<0.05). Based on this study it could be concluded that the GPP has potential as an alternative feed supplement in concentrate diets which can result in improved rumen fermentation efficiency, digestibility and microbial protein synthesis in steers fed on treated rice straw.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.149-159
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• 1988

This study was made to investigate the effect of pesticides on microflora to nitrogen metabolism, nitrification and nitrogen fixing activity in the submerged soil. The results are summarized as follows; Pesticides treatment leaded to the inhibition of $NH_4{^-}$-oxdizers, $NO_3{^-}$-reducer, and denitrifying bacteria population. $NO_2{^-}$-oxdizers were inhibited by cabamate compounds, carbofuran and MIPC. Simetryne seemed to stimulate the denitrifying bacteria at 60 days after incubation. Generally, formation of $NO_2{^-}$ and $NO_3{^-}$ tended to decrease by pesticides application. Pesticides application stimulated Azotobacter and Clostridia populations, while simetryne inhibited Athiorhodaceae and Thiorhodaceae. However acephate seemed to be stimulatory to blue-geen algae. $C_2H_2$-reducing activity by acephate was clearly appeared. The change of $C_2H_2$-reducing activity did not seems to be affected by pesticides application.