• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.3
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• pp.215-222
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• 2016

Nitrogen (N) fertilizer management is one of the important aspects of economic production of sorghums in sustainable agriculture. The aim of the study was to evaluate the effects of different N application rates and its split N application methods on productivity, growth characteristics, N accumulation, N use efficiency (NUE), and feed value of Sorghum ${\times}$ Sudangrass hybrids. Treatments consisted of five N application rates (0, 150, 200, 250, and $300kg\;ha^{-1}$) and two split N application methods (40% in basal N, 30% at the growing stage, and 30% after the first harvest vs. 50% in basal N and 50% after the first harvest). Plant height, leaf width, and stem diameter were increased ($p{\leq}0.05$) with increasing N fertility rates at each harvest. Chlorophyll content (expressed as SPAD values) was the highest at a rate of $300\;kg\;N\;ha^{-1)$ (first harvest, 46.32; second harvest, 33.09). It was the lowest at zero N (first harvest, 21.56; second harvest, 18.5). Total N, N uptake, and NUE were increased with higher N rates. Split N application had little effect on total N, amount of N uptake, or NUE. Total dry matter yields were the highest ($21,715\;kg\;ha^{-1}$) at a rate of $300\;kg\;N\;ha^{-1}$. It was the lowest ($10,054\;kg\;ha^{-1}$) at zero N. Our results suggest that more than $300\;kg\;N\;ha^{-1}$ can improve dry matter yield to be above 116% compared to zero N, thus enhancing the agronomic characters of sorghums. However, no significant effect had been found for split N application. Further work is needed to determine the optimal N levels and the effect of split N application rates.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.48-53
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• 2006

The purpose of this paper is to investigate the optimal condition of the SynGas production by reforming of propane using plasmatron. Plasma was generated by air and arc discharge. The effects of applied steam, $CO_2$ or Ni-catalyst on propane conversion, yield of hydrogen and $H_2/CO$ ratio as well as correlation of syngas were studied. When the variations of $O_2/C_3H_8$ flow ratio, $H_2O/C_3H_8$ flow ratio and $CO_2/C_3H_8$ flow ratio were $0.94{\sim}1.48,\;4.3{\sim}10\;and\;0.8{\sim}3.05$ respectively, Under the condition mentioned above, result of $H_2O/C_3H_8$ flow ratio was maximum $H_2$ concentration, or $28.2{\sim}31.6%$, and result of $H_2O/C_3H_8$ flow ratio with catalyst was minimum CO concentration or $6.6{\sim}7.1%$ and the ratio of hydrogen to carbon monoxide($H_2/CO$) were $3.89{\sim}4.86$.

• Microbiology and Biotechnology Letters
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• v.11 no.1
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• pp.59-66
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• 1983

Cultural conditions for the production of extracellar $\beta$-galactosidase by Loctobacillus sporogenes, a spore forming lactic acid bacterium, were investigated with shaken flask and jar fermenter cultures. The fermentation medium giving maximum $\beta$-galactosidase yield was found to consist of 1 % lactose as a carbon source, 1.5% peptone as an organic nitrogen source. 0.2% ammonium sulfate as an inorganic nitrogen source, 0.8% ammonium phosphate dibasic as a phosphorus source, and 0.05% potassium chloride and 0.001% ferric chloride as mineral source. Optimal initial pH of the medium was 7.0 and the highest enzyme excretion was observed after 40 hours of cultivation at 37$^{\circ}C$. In this experiment, the 500$m\ell$ conical flask containing 50-200$m\ell$ of medium was shaken at 140 strokes per minute with 7cm amplitude in a reciprocating shaker. The maximum enzyme value attained was 38 U/$m\ell$ of the culture broth which was found to be slightly higher than the highest intermolecular enzyme activity (30 U/$m\ell$) observed after 24 hours of incubation. In the fermentor culture, the fermentation profile was shown to be similar to that observed in the shaken flask experiment. But the maximum extracellular enzyme activity was 45 U/$m\ell$ to be even higher than the value obtained with the shaken flask culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.3
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• pp.247-252
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• 2002

To prepare the edible film based on fish protein, the optimal conditions for extracting soluble protein from Alaska pollack ( Theragra chalcogramma) and mackerel (Scomber japonious) muscle were defined. The effects of protein concentration, pH and temperature of protein solution on the physical properties of films were also investigated, Contents of moisture, crude protein, crude lipid and ash in Alaska pollack muscle were 79.6, 18.2, 0.6 and $1.2\%$, respectively. Contents of moisture, crude protein, crude lipid and ash in mackerel muscle were 69,1, 20.1, 9,5 and $1.3\%$, respectively. Both soluble protein contents extracted from Alaska pollack and mackerel were the highest at pH 12.0, and then un 2.0, 11.0. But they were extracted a little at neutral range. forward the recovery yield of protein by controlling isoelectric point was the highest at pH 4.8 ($79.8\%$) for Alaska pollack and at pH 5.0 ($64.1\%$) for mackerel, For the preparation of protein films from both Alaska pollack and mackerel, the most effective conditions of film forming solution were achieved, after supplied fish protein 4 g (glycerol 1,6 g) in 100 mL of distilled water, by adjusted to pH 10.0 and then heated at $90^{\circ}C$.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.342-349
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• 2010

Lactic acid is widely used in the food, chemical and pharmaceutical industries, and there is an increasing demand for lactic acid as the raw material of poly lactic acid(PLA), which is a biodegradable polymer. Lactic acid production has been changing over from production by synthesis to production by fermentation, since the fermentation process is more nature friendly and economic. However, the fermentation method generates excess water and impurities with high boilers. The presence of high boilers and non volatility of lactic acid makes the separation of lactic acid very difficult job. Also, the purification-separation process requires the many investment costs and energy costs. Reactive distillation concept was also introduced for the process, giving higher selectivity and yield compared to the convention method. We introduce a new highly integrated process, reactive diving wall column, to reduce the capital and energy cost for producing a pure lactic acid. The reactive dividing wall column combines reactive distillation and dividing wall column. We compared capital and energy consumption required for the purification of lactic acid the between the proposed design structures. And we examined the effect of major process variables on the process performance and determined optimal process.

• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.131-137
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• 1998

The cellulase components were partially purified from the culture filtrate of the alkalophilic bacterium Pseudomonas sp. AC-711 and its enzymatic properties were characterized. The specific activity of the purified major enzyme component was 3.5 units/mg protein as carboxymethyl cellulase and the yield was 23% of the total activity of the culture broth. The molecular weight of the component was 46,000 and the Km and Vmax on CMC were determined as $15.4mg\;mL^{-1}$ and $4.17{\mu}moles\;mL^{-1}\;min^{-1}$, respectively. The enzyme was stable at the temperatures below $60^{\circ}C$ and at the pH range of 4.0~11.0, and the optimal temperature and pH were $60^{\circ}C$ and pH 8.0, respectively. The enzyme activity was not significantly affected by the common surfactants (concentration: 0.05%) such as ${\alpha}$-olefin sulfonate, linear alkylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide and Tween 80. The enzyme was activated by the metal ions such as $Ca^{2+}$, $Cu^{2+}$, $Co^{2+}$, whereas inhibited by $Hg^{2+}$ and $Zn^{2+}$. The enzyme exhibited relatively high activity toward amorphous CMC as compared with crystalline substrates such as filter paper and avicel.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.479-483
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• 2006

[ ${\beta}-Glucan$ ], one of the cell wall components, is most plentiful polysaccharides in cell wall and has several advantages in immune system. In yeast ${\beta}-glucan$ is mainly contained in the yeast cell wall, and thus it is important to produce high levels of cell mass for the mass production of yeast ${\beta}-glucan$. The best carbon and nitrogen sources on cell mass production were high fructose syrup and yeast extract. Response surface methodology (RSM) was very potential tool for the optimization of process factor and medium component. It was applied to estimate the effects of medium components on the production of cell mass. Optimal concentrations of high fructose syrup and yeast extract by response surface methodology were 8.0% (v/v) and 5.2% (w/v), respectively and the cell mass predicted was $17.0\;g/{\ell}$ at 20 h of cultivation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.747-752
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• 2004

Alginates were extracted from the Laminaria religiosa, Undaria pinnatifida, and Hizikia fusiforme by using four different extraction methods and compared the yields of alginate. Acid-alkali soluble alginate (AASA) extraction method from Undaria pinnatifida resulted in the best yield of alginate among the seaweeds. The optimal condition for extracting alginate from Laminaria religiosa was 0.4 N H$_2$SO$_4$ and 3% NaCO$_3$ concentrations at the AASA extraction method. The alginate yields of hot water extractable material (HWEM) water soluble alginate (WSA), alkali soluble alginate (ASA) and AASA in Hizikia fusiforme were 18.6, 4.7, 22.5 and 26.5%, respectively. The alginates manufactured by the WSA extraction method showed more bright color than those of the ASA and AASA extraction methods. The alginate prepared by the ASA extraction method from Hizikia fusiforme showed the higher viscosity than that of the ASA extraction method. The molecular weight of the alginate from Hizikia fusiforme was 33.3 kDa to 121.6 kDa depending on the extraction method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.736-740
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• 2004

Preparation of ginseng concentrate with high content of acidic polysaccharide from white tail ginseng marc that was obtained after preparation of white tail ginseng extract. As a result of extraction of white tail ginseng under various concentrations of ethanol (0∼90%), both amount of acidic polysaccharide and extraction yield decreased by increasing the ethanol concentration. However, acidic polysaccharide extracted by water from white tail ginseng marc was increased in accordance with the increase of ethanol concentration. The optimal condition for the extraction of acidic polysaccharide from the marc was treatment of $\alpha$-amylase in 390∼650 unit/g residue/15 mL of distilled water for 5 min at 4$0^{\circ}C$. The amount of acidic polysaccharide in water extract of the marc was increased from 8.3% to 10.5% by the treatment of $\alpha$-amylase. A new ginseng extract mixture was manufactured by mixing 50% ethanol extract of white tail ginseng and water extract of alcoholic residue in the ratio of 8:2 (w/w). Crude saponin content and acidic polysaccharide content were 10.5% and 17%, respectively. The mixture had a same crude saponin content and twice acidic polysaccharide content comparing to 50% ethanol extract of white tail ginseng. It suggests that preparation of new ginseng concentrate with high content of acidic polysaccharide from white tail ginseng marc has high potencies in the utilization of waste material.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.341-353
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• 1995

Previous study had shown the diversities in the propriety for optimal bond strength on the concentration of the etchant. The aim of present study in vitro was to evaluate and compare the shear bond strength of orthodontic brackets to enamel and to measure the depth of etch on the phosphoric acid concentrations. A hundred and seventy six extracted bovine lower centrals were ground to yield flat surfaces and etched by the concentration $0%,\;5%,\;10%,\;20%,\;30%,\;40%,\;50%,\;60%,\;70%,\;80%\;and\;85\%$ of phosphoric acid respectively during 60 seconds. The shear bond strength of orthodontic brackets, the depth of etch and surface roughness of the enamel were measured, and scanning electron microscopic observations on the etched enamel surfaces were carried out. The data obtained from the very experiments were processed and statistically analyzed and evaluated. The gradual increase in the depth of etch to enamel as the accretion of the concentration of the phosphoric acid upto $40-50\%$ and decline henceforth were manifested. The surface roughness showed no correlation with the depth of etch, yet moderate correlation with the shear bond strength of brackets. Scanning electron microscopic investigation revealed that morphological patterns of the etched enamel surfaces for $5\%\;to\;40\%$ of concentrations were even and homogenous, and those for $50\%$ as well as $60\%$ exhibited the overetched and unhomogenous. The shear bond strengths kom $10\%\;to\;60\%$ of concentration showed no statistically significant differences. It was suggested that the shear bond strengths at $5\%\;and\;70\%$ were sufficient to tolerate the force levels of the ordinary orthodontic treatment notwithstanding to be significantly lower than those from $10\%\;to\;60\%$ phosphoric acid solution.