• Resources Recycling
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• v.12 no.6
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• pp.57-63
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• 2003

In this study, the separation of neodymium was investigated from NdFeB permanent magnet scrap. Decomposition and leach-ing process of NdFeB permanent magnet scrap by oxidation roasting and sulfuric arid leaching were examined. Neodymium could be separated from iron by double salt precipitation using sodium sulfate. The optimum conditions established for decom-position and leaching are as follows: oxidation roasting temperature is $500^{\circ}C$ for sintered scrap and $700^{\circ}C$ for bonded scrap, concentration of sulfuric acid in leaching solution is 2.0 M, leaching temperature and time is $50^{\circ}C$ and 2 hrs, and pulp density is 15%. The leaching yield of neodymium and iron was 99.4% and 95.7% respectively. The optimum condition for separation of neodymium by double-salt precipitation was 2 equivalents of sodium sulfate and $50^{\circ}C$ The yield of neodymium was above 99.9%.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.41-48
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• 1999

This study was intended to investigated the effect of pulp type and intital calendering on the properties of recycled fiber. As the number of recycling is increased, at least by the fourth recycling , the freeness of the SW-BKP and HW-BKP increased. And then that decrease after the fifth recycling. Especially the freeness of CTMP increased more rapidly than any other pulp in first recycling. And there was no difference of freeness in all kind of pulp by initial calendering . The speed of dewatering in making sheet consistetly became slow by proceeding recycling on condition of all calendering. and the order of the speed of dewatering was as followed. CTMP>HW-BKP>SW-BKP. However in case of HW-BKP, which was low -yield pulp, the tendency of the speed of dewatering was similar to that of CTMP which was high-yield pulp and had high content lignin . There was no change of fiber length and no effect of calendering by recycling of HW-BKP and CTMP. Howeverfiber length of SW-BKP generally decreased, especially in calendering of high temperature and high pressure conditions. The WRV of SW-BKP diminished by proceeding recycling but that of HW-BKP and CTMP diminished in the first recycling and then there was no change of the WRV of HW-BKP and CTMP. The contents of fines of HW-BKP consistently decreased by the fourth recycling and then increased in the fifth recycling . On the other hand there was no tendency in the content of fines of SW-BKP and CTMP by the number of recycling.

• Journal of Korean Society of Steel Construction
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• v.29 no.1
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• pp.73-80
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• 2017

In this study, cyclic loading analysis was conducted in order to understand the behavior of self-centering connections based on the number of PT(posttensioning) strands and initial posttensioning force. The initial posttensioning force needs to be above the yield moment of an angle for obtaining noticeable self-centering effect and it is proper that decompression moment ratio needs to be below 0.35 to minimize the residual displacement of major elements. As the number of PT strands increased, self-centering capacity also improved since initial posttensiong force in each PT strand has been decreased. It is also appropriate that initial posttensiong force needs to be less than or equal to 75% of yield strength of PT strands.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.157-167
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• 2016

The interspecific estimation for tolerance capacities of upland crop species to excessive soil water stress in paddy field is significant in agricultural practices. Most of upland crops can be damaged by either excessive soil water or capillary rise of the water table during rainy season in paddy fields. The major objective of this study was to evaluate water stress of upland crops under different drainage classes in converted paddy field. This experiment was carried out in poorly drained soil (PDS) and imperfectly drained soil (IDS) of alluvial sloping area located at Toero-ri, Bubuk-myeon, Miryang-si, Gyeongsangnam-do. The soil was Gagog series, which was a member of the fine silty, mixed, nonacid, mesic family of Aeric Endoaquepts (Low Humic-Gley soils). Two drainage methods, namely under Open ditch drainage methods (ODM) and, Closed pipe drainage methods (PDM) were installed within 1-m position at the lower edge of the upper paddy fields. The results showed that sum of excess water days ($SWD_{30}$), which was used to represent the moisture stress index, was 42 days (the lowest) in the PDM compared with 110 days in the ODM. Most of upland crops were more susceptible to excessive soil water during panicle initial stage on more PDS than on IDS. Yield of upland crops in the PDM was continuously increased by the rate of 15.1% on sorghum, 15.4% foxtail millet, 53.6% proso millet, 49.6% soybean and 47.9% adzuki bean as compared in the ODM. The capacity for tolerance by excessive soil water based on yield of each upland crop in the poorly drained sloping paddy fields was the order of sorghum, soybean, foxtail millet, proso millet and adzuki bean. Therefore, Sorghum is relatively tolerant to excessive soil water conditions and, may be grown successfully in converted paddy field.

• Food Science and Preservation
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• v.14 no.1
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• pp.100-104
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• 2007

This study was designed to investigate quality characteristics and conditions of acetic acid fermentation of kiwi vinegar following addition of oligosaccharide. During the acid fermentation alcohol concentration and total acidity were shown to be 6% and 1.0%, respectively, with the highest acetic acid yield. Acetic acid fermentation of kiwi following addition of oligosaccharide showed the highest acetic acid yield with 15% oligosaccharide. Free forms of sugars in kiwi vinegar were detected to be fructose, glucose and maltose. Organic acid of kiwi vinegar were malic, lactic, acetic, citric and succinic acid. Total content of organic acid was shown to be the highest with 15% oligosaccharide. Mineral content was shown to be lower when oligosaccharide amount was increased. In conclusion, oligosaccharide addition has an insignificant effect on acetic acid fermentation of kiwi, and was evaluated to be suitable at 15%.

• Korean Journal of Plant Resources
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• v.29 no.6
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• pp.704-711
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• 2016

Tomatoes are considered as one of the main components of daily meals in most households. Thus, it is important to invest in studies enhancing their yield and nutritional value. The study evaluated the effect of wood vinegar (WV) on tomato under greenhouse conditions. Data on fruit number, fruit weight, and plant height were recorded. Total phenolic content (TPC) and antioxidant activity of tomato were determined using the Folin-Ciocalteu reagent and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, respectively. FRR-CF+500x-WV significantly increased the fruit number (86.11%) and fruit weight (81.78%) over the control. Results were comparable to HRR-CF+250x-WV, indicating that conventional fertilizer and WV may have synergistic effect on each other. TPC and scavenging effect on DPPH radical was improved by 250x-WV application. The increase in the phenolic compounds can be attributed to WV as a direct source or as a factor triggering the plants to produce more secondary metabolites with the purpose of increasing natural defenses. The significant effect obtained by applying the full recommended rate of conventional fertilizer on the carotenoid content was due to the availability of the major nutrients needed by the plant. Correlation analysis showed that carotenoids have negative correlation with TPC and DPPH. However, TPC and DPPH showed that these are positively correlated with each other. Tomatoes are excellent source of antioxidants associated with the reduction of some human diseases and improved health. The results provided evidence that WV alone and/or its combination with conventional fertilizers has favorable effects on the quality of tomato.

• Korean Journal of Medicinal Crop Science
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• v.8 no.3
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• pp.209-215
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• 2000

This study was conducted to improve the productivety of Ligusticum chuanxiong HORT. and Cnidium officinale MAKINO by establishing the effects of cultivating conditions. Growth characteristics of underground part of L. chuanxiong under the different mulching treatment showed the highest growth and yield in black vinyl mulching treatment. The highest dry weight of underground parts per plant in mulching treatment was 47.9g at white shading treatment while the lowest one was 16.5g at black shading treatment. Growth characteristics of underground parts C. officinale under the different mulching treatment were the higher in black vinyl mulching rather than in rice straw mulching and white vinyl mulching. Dry weight of underground parts per plant of C. officinale under the different shading treatments was the highest(37.8g) under the white shading while it was lowest(12. 2g) under the black shading.

• Journal of the Korean Ceramic Society
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• v.31 no.11
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• pp.1401-1413
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• 1994

The synthesis of kaolinite mineral from domestic diatomite for silica resource, commercial vailable gibbsite or alumina for alumina resource were made under various hydrothermal treatment, and the sythetic effect of acidic mineralizers, temperature treatment with time duration, particle size of alumina on formation of kaolinite mineral and the plastic properties of synthesized kaolinite were investigated. The various acidic mineralizers which are HCl, HNO3, H2SO4 and Oxalic acid were employed for hydrothermal reaction in the range of 0.01 mol/ι to 2 mol/ι concentration of each mineralizers. It was found that HCl in the level of 1 mol/ι solution produced highly yields of well-crystallized and platy form kaolinite mineral and gave the most effective extraction of iron oxide, compared to that of others, that HNO3 produced highly yield of kaolinite but lower extraction of iron oxide, that H2SO4 produced low yield of kaolinite and formed alunite mineral, and that oxialic acid formed spherical crystalline kaolinite and gave low extraction of iron oxide. Moreover, it showed that kaolinite minerals were well synthesized in a wide range of less than 2 mol/ι acids, but were poorly synthesized at more than 2 mol/ι acids. However, boehmite and kaolinite were coexistently formed in the temperature range of 18$0^{\circ}C$ and 20$0^{\circ}C$ when the calcined diatomite and gibbsite were involved. The well-ordered kaolinite mineral as a platy form was highly synthesized in the temperature range of 220 and 24$0^{\circ}C$, when the same marterials as above were used with treatment of 1 mol/ι HCl solution. The results also revealed that the size of crystalline platy form kaolinite, synthesized from alumina and calcined diatomite with treatment in 1 mol/ιHCl solution at 24$0^{\circ}C$, was much larger than that of gibbsite and calcined diatomite shown previously, and that kaolinite and corundum minerals were coexistently formed under any hydrothermal treatment conditions. The plasticity of synthesized kaolinite from under 2 ${\mu}{\textrm}{m}$ alumina and calcined diatomite was very poor, and that of the synthesized kaolinite from raw diatomite and gibbsite gave higher than that of calcined diatomite and gibbsite.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.369-373
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• 2004

In order to elucidate the possibility of artificial production of p. ferulae by solid-state culture, the optimization of culture conditions was carried out. When $NH_4H_2PO_4$ and $CaCO_3$ were used in the cultures using test tube with 30 g of Populus sawdust at $25^{\circ}C{\pm}1$ in the dark, the favored mycelial growth was observed with $1\%$ of $NH_4H_2PO_4$ and the production of polysaccharide was 7.85 mg/100 mg of mycelium with $1\%$ of $CaCO_3$. The mixtures of $80\%$ of Populus Sawdust and $20\%$ of rice bran at $60\%$ of water content were determined to be optimal for the production of fruiting bodies in the sawdust culture. When three treatments containing various ratios of garlic powder were conducted, yields of fruiting bodies were drasti[ally higher than those of Synthetic mixture without garlic powder The highest yield (143 g/bag) was obtained with $7\%$ garlic powder. The yield of synthetic mixture containing $7\%$ of garlic powder was $83\%$ higher than that of Sawdust culture. The reason why garlic powder did support growth was not clear but it is possible that garlic powder might contain effective components for the formation of fruiting body. The optimal synthetic mixture composition consisted of cotton seed $77\%$, lime $6.4\%,\;K_2HPO_4\;0.2\%,\;KH_2PO_4\;0.2\%,\;CaHPO_4\;0.2\%$, corn flour $4\%$, wheat flour $5\%$, and garlic pow-der $7\%$.

• KSBB Journal
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• v.27 no.3
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• pp.137-144
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• 2012

Among various pretreatment processes for bioethanol production, extrusion pretreatment, one of cheap and simple process was investigated to efficiently produce fermentable sugars from micro alga, Chlorella sp. The biomass was pretreated in a single screw extruder at five different barrel temperatures of 45, 50, 55, 60 and $65^{\circ}C$, respectively with five screw rotation speed of 10, 50, 100, 150 and 200 rpm. The pretreated biomass was reacted with two different hydrolyzing enzymes of cellulase and amyloglucosidase since the biomass contained different types of carbohydrates, compared to cellulose of agricultural by-products such wheat and corn stovers, etc. In general, higher glucose conversion yield was obtained as 13.24 (%, w/w) at $55^{\circ}C$ of barrel temperature and 100 rpm of screw speed conditions. In treating 5 FPU/glucan of cellulase and 150 Unit/mL of amyloglucosidase, ca. 64% of cellulose and 40% of polysaccharides in the micro alga were converted into glucose, which was higher yields than those from other reported data without applying an extrusion process. 84% of the fermentable sugars obtained from the hyrolyzing processes were fermented into ethanol in considering 50% of theoretical maximum fermentation yield of the yeast. These results implied that high speed extrusion could be suitable as a pretreatment process for the production of bioethanol from Chlorella sp.