• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.769-779
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• 2020

This study investigates the selective fractionation of lignin with uniform structures and lower molecular weight. Lignin solubilization was first performed using a solution of acetic acid (AA) and hydrogen peroxide (HP) (4:1, (v/v)) to form peracetic acid (PAA), which is a strong oxidant. After the PAA-induced solubilization that occurred at 80℃, totally soluble lignin was extracted by ethyl acetate (EA) and divided into organic- and water-soluble fractions. The EA fraction was then fractionated by open-column using three solutions (chloroform-ethyl acetate, methanol, and water) sequentially. With an increase in the solvent polarity during the fractionation step, the molecular weight of the lignin-derived compounds in the fraction increased. Remarkably, some lignin fractions did not have aromatic structures. These fractions were identified as carboxylic acid-containing polymers like poly-carboxylates. These results conclude that the selective production of lignin-derived polymers with specific molecular weight and structural characteristics could be possible through open-column fractionation.

• Journal of the Korean Wood Science and Technology
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• 제48권3호
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• pp.405-413
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• 2020

Recycling of ionic liquid (1-ethyl-3-methylimidazolium acetate, [EMIM]Ac) after the pretreatment of Salix gracilistyla Miq. was conducted and the effect of the recycling number on the enzymatic saccharification yield was investigated. Enzymatic saccharification was performed using an enzyme cocktail (Acremonium cellulase and Optimash BG) at 50 ℃ for 72 h. All recycled [EMIM]Ac samples showed a lower amount of water soluble fraction than pure [EMIM]Ac. On increasing the recycling number from 1 to 4, the amount of water soluble fraction decreased from 18% to 15%. The X-ray diffraction pattern of the products pretreated with recycled [EMIM]Ac showed cellulose I crystalline polymorph. The crystallinity of the product pretreated with recycled [EMIM]Ac was 47-49%, which was lower than 33% of that with pure [EMIM]Ac. The yields of glucose and xylose decreased in the pretreatment with recycled [EMIM]Ac compared to that with pure [EMIM]Ac.

• 한국물환경학회지
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• 제20권6호
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• pp.708-713
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• 2004

This study was performed to investigate the variations of hydrophilic and hydrophobic organic matter fractions in soluble organic matter according to livestock wastewater treatment by ionized gas and coagulation effect to these fractions after ionized gas contact. As a result of experiment, because of ionized gas contact, particle in the surface of livestock wastewater was more smaller and the result was consisted of particle size analysis and the amount of small size was increased. Also, we confirmed that organic matters in livestock wastewater by ionized gas contact were removed. The relation equation between ionized gas contact time(X) and $TCOD_{cr}$(Y) was shown as yscale(y)=3.748-0.431* xscale(X). That between ionized gas contact time(X) and $TCOD_{cr}$(Y) was yscale(y)=3.283-0.463* xscale(X). As respects the HPL(hydrophilic matter)and HPO(hydrophobic matter) fractions of raw in livestock wastewater treatment plant, HPL fraction was 53.2% and HPO fraction was 46.8%. But, HPO fraction according to ionized gas treatment was increased at 30min and after that time, HPL fraction was increased. Also, when we performed coagulation process after ionized gas treatment of raw wastewater, the removal efficiency of organic matter was the highest at 30min of ionized gas treatment because of the variation of HPL and HPO fractions in organic matter by ionized gas. In coagulation process following after ionized gas process, HPO was removed more effective than HPL.

• 한국초지조사료학회지
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• 제11권1호
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• pp.12-16
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• 1991

용액중 칼륨수준을 달리한 조건에서 수경재배된 오차드그라스에 들어있는 무기물중 칼륨, 마그네숨, 칼슘을 각각 물, 알코올, 산에 가용성언 깃으로 성분분획했는데, 그 결과는 다음과 같다. (1) 목초에 함유된 칼륨함량 전체에 대한 물, 알코올, 0.5% 개산에 의해 용출된 성분의 비솔은 수경액중 칼륨수준에 영향을 받지 않았으며 각각 90~93%,4~6%,2~3% 의 범위였다,(2) 마그네슘량의 약 80%가 수용성이었으며, 14~22%는 0,5% 염산에 의해 용출되었다 (3) 칼슘함량 전체에 대한 물, 알코올, 0.5% 및 1몰의 염산에 의해 용출된 성분의 비솔은 수경액중 칼륨수준에 영향을 받았는데. 각각 26~46%, 44~54% 및 8~22%의 범위였다. 이상의 결과로부터, 3가지 무기물중 물에 의해 용출되는 성분의 비솔은, 칼륨>마그네슘>칼슘의 순서였으나, 산에 의해 용출되는 성분의 비솔은 그 반대인 칼륨<마그네슘<칼슘이였다.

• 한국환경과학회지
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• 제28권5호
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• pp.511-520
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• 2019

This study was investigated to improve the phosphorus release and water quality by transformation of sedimentary P fraction for application of $CaO_2$. For the experiment, 0.5% (w/w) of $CaO_2$ was homogenized in the sediment and incubated with the control for 20 days. The analytical results showed that pH increased with $CaO_2$ and redox potential (ORP) was improved in the sediment of the reactor. The growth rate of chlorophyll-a was lower in the $CaO_2$ reactor and Dissolved Oxygen (DO) of overlying water maintained higher than that of the control. Total phosphorus (T-P) concentration in the overlying water increased from the initial concentration to 0.304mg/L in the control at 20 days. The reactor of $CaO_2$ was lowered by 29.3%. Ex-P, Fe-P and Ca-P in sediment P fraction were increased with the $CaO_2$. The formation of bound Fe-P and Ca-P in the sediments seemed to control the release of P by removing the Soluble Reactive Phosphorus (SRP) presented in the pore water. From the result, this indicated that the reduction of P release from the sediments seems to be effective in suppressing the eutrophication of P and improving the oxygen condition in the water quality with the application of $CaO_2$.

• 한국환경과학회지
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• 제29권1호
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• pp.79-93
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• 2020

To determine the size distributions of water-soluble inorganic ionic species (WSIS) in roadside aerosols, sampling experiments were carried out in the urban roadside area of Jeju City on August 2018 and January 2019 by using the eight-stage cascade impactor sampler. The mass of roadside aerosols were partitioned at 57% in fine fraction, 36-37% in coarse fraction, and 6-7% in giant fraction, regardless of summer and winter. The mass concentrations of WSIS except for Na+ and SO42- in roadside aerosols were higher in winter than in summer. The size distributions of Na⁺, Mg²⁺, Ca²⁺ and Cl^- were characterized by bimodal types with coarse particle mode peaking around 3.3-4.7 ㎛ and 5.8-9.0 ㎛. The size distributions of NO₃^- and K⁺ shifted from a single fine mode peaking around 0.7-1.1 ㎛ in winter to bimodal and/or trimodal types with peaks around coarse mode in summer. SO₄^2- and NH₄⁺ showed a single fine mode peaking around 0.7-1.1 ㎛. The MMAD of roadside aerosols was lower than that of Na⁺, Mg²⁺, Ca²⁺ and Cl-. Based on the marine enrichment factors and the ratio values of WSIS and the corresponding value for sea water, the composition of roadside aerosols in Jeju City may be practically affected by terrestrial sources rather than marine source.

• 한국패류학회지
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• 제26권2호
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• pp.157-163
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• 2010

원유의 WSF가 북방전복의 유생 및 치패 발생에 미치는 영향을 알아보기 위하여 발생소요시간, 발생률 및 부착률, 생존율, 유생 및 부착치패의 각성장 그리고 수온에 따른 치패의 생존율 및 아가미의 조직학적 변화를 조사하였다. 발생 소요시간은 대조구에 비해 노출구에서 느리게 나타났다. 발생률 및 부착률은 0.4 mg/L 이상의 농도에서 대조구에 비해 유의적인 감소를 보였다 (P < 0.05). 북방전복 유생의 생존율은 0.4 mg/L 이상에서, 부착치패는 2.4 mg/L 이상에서 유의적인 감소가 나타났다 (P < 0.05). 각성장은 2.4 mg/L 이상의 농도에서 대조구에 비해 감소하였다 (P < 0.05). 수온에 따른 치패의 생존율은 $17^{\circ}C$와 $25^{\circ}C$ 모두 노출농도에서 감소하였으며, 특히 고수온에서 전체적인 생존율이 낮게 나타났다. 또한 아가미에서 나타난 조직학적 변화는 주로 새엽 상피세포 핵의 위축 및 상피세포의 공포화 그리고 상피층의 괴사를 동반한 붕괴 등이 관찰되었으며, 이는 $17^{\circ}C$에 노출된 개체들 보다는 고수온인 $25^{\circ}C$에 노출된 개체들에서 심하게 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권10호
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• pp.1386-1398
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• 2010

Soybean contains a high concentration of carbohydrates that consist mainly of non-starch polysaccharides (NSP) and oligosaccharides. The NSP can be divided into insoluble NSP (mainly cellulose) and soluble NSP (composed mainly of pectic polymers, which are partially soluble in water). Monogastric animals do not have the enzymes to hydrolyze these carbohydrates, and thus their digestion occurs by means of bacterial fermentation. The fermentation of soybean carbohydrates produces short chain fatty acids that can be used as an energy source by animals. The utilization efficiency of the carbohydrates is related to the chemical structure, the level of inclusion in the diet, species and age of the animal. In poultry, soluble NSP can increase digesta viscosity, reduce the digestibility of nutrients and depress growth performance. In growing pigs, these effects, in particular the effect on gut viscosity, are often not so obvious. However, in weaning piglets, it is reported that soy oligosaccharides and soluble NSP can cause detrimental effects on intestinal health. In monogastrics, consideration must be given to the anti-nutritive effect of the NSP on nutrient digestion and absorption on one hand, as well as the potential benefits or detriments of intestinal fermentation products to the host. This mirrors the needs for i) increasing efficiency of utilization of fibrous materials in monogastrics, and ii) the maintenance and improvement of animal health in antibiotic-free production systems, on the other hand. For example, ethanol/water extraction removes the low molecular weight carbohydrate fractions, such as the oligosaccharides and part of the soluble pectins, leaving behind the insoluble fraction of the NSP, which is devoid of anti-nutritive activities. The resultant product is a high quality soy protein concentrate. This paper presents the composition and chemical structures of carbohydrates present in soybeans and discusses their nutritive and anti-nutritive effects on digestion and absorption of nutrients in pigs and poultry.

• 한국환경과학회지
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• 제26권4호
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• pp.447-456
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• 2017

Chemical properties of aerosols were investigated by analyzing the inorganic water-soluble content in $PM_{2.5}$ collected in the downtown area of Jeju City in Jeju Island. Due to an increase in both the number of visiting tourists and the size of local population, the number of cars in this area is increasing, causing an increase in $PM_{2.5}$. Eight $PM_{2.5}$-bound major inorganic ions were analyzed during the summer and winter periods. The water-soluble inorganic component represents a significant fraction of $PM_{2.5}$. In particular, secondary inorganic aerosols contribute 36.2% and 47.5% of $PM_{2.5}$ mass in summer and winter, respectively. Nitrate concentrations increase for $[NH_4{^+}]/[SO_4{^{2-}}]$>1.5, and excess ammonium, which is necessary for ammonium nitrate formation, is linearly correlated with nitrate. These results are clearly observed during the winter because conditions are more conducive to the formation of ammonium nitrate. A significant negative correlation between Nitrogen Oxidation Ratio (NOR) and temperature was observed. The obtained results can be useful for a better understanding of the aerosol dynamics in the downtown area in Jeju City.

• Natural Product Sciences
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• 제7권1호
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• pp.1-4
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• 2001

The antioxidant activity of Pinus densiflora was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The methanol extract of P. densiflora showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate>n-butanol>water>dichloromethane> n-hexane fraction. The ethyl acetate soluble fraction exhibiting strong antioxidant activity was further purified by repeated silica gel column chromatography. Antioxidant (+)-catechin was isolated as one of the active principles from the ethyl acetate fraction, together with the inactive components, dihydrokaempferol and 1-O-benzoylglucose. The radical scavenging effect of (+)-catechin on DPPH radical exceeded to that of L-ascorbic acid which is a well known antioxidant.