• Korean Chemical Engineering Research
• /
• 제60권3호
• /
• pp.414-422
• /
• 2022

본 연구의 목적은 국내 대표적인 농경잔류물인, 볏짚과 보릿짚을 이용하여 헤미셀룰로오스 부분의 최대 가용화를 위한 산 촉매 열수 분별공정의 타당성을 조사한 것이다. 1.2-2.9 범위의 반응가혹도(CS; Combined reaction severity)에서 다양한 분별 조건들을 사용하여 초기 반응조건 기준을 설정했다. 볏짚의 경우, 160 ℃의 반응온도, 0.75%(w/v)의 H₂SO₄, 20분의 반응시간, 그리고 1:15의 고체/액체 비율을 가진 반응 조건에서 56.6%의 헤미셀룰로스 당 수율을 얻을 수 있었으며, 보릿짚의 경우, 150 ℃ 반응온도, 0.75%(w/v) H₂SO₄, 15분의 반응시간, 1:10의 고체/액체 비율에서 83.0%의 헤미셀룰로스 당 수율을 얻었다. 따라서, 볏짚과 비교하여 보릿짚의 경우 산촉매 열수분획을 효과적으로 수행할 수 있었다. 분별과정 후 남은 분획된 고형분은 볏짚과 보릿짚에서 각각 48.5%와 57.5%였다. 분별된 볏짚과 보릿짚의 XMG(Xylan+Mannan+Galactan) 함량은 17.3% 및 17.6%에서 6.0% 및 2.6%로 각각 감소하였으며, 이는 원료 짚 기준으로 각각 16.7% 및 8.5%에 해당한다. 또한, 보리 짚의 산촉매 열수분별 과정에서 과도한 분해로 인해 셀룰로오스 및 XMG의 5.6% 및 8.5%만 손실된 반면, 볏짚의 셀룰로오스 및 XMG 손실은 6.4% 및 26.6%이었다. 볏짚의 헤미셀룰로스 당은 산 촉매 열수 분별공정중, 다소 높은 반응가혹도로 인해 심하게 과분해된 것에 기인한다.

• 동의생리병리학회지
• /
• 제16권1호
• /
• pp.160-164
• /
• 2002

The water extract of Sophorae radix was tested for its preventive effects against cardiovascular anaphylaxis elicited in experimental animals. H₂O and ethyl acetate fractionation of Sophorae radix water extract improved anaphylactic cardiac dysfunction in passively sensitized isolated guinea hearts: improvement was noted in the maximal contractile force, post-challenge contractile force, post-challenge coronary flow and creatine kinase change elevation. These results suggest that H₂O and ethyl acute fractionation of Sophorae radix water extract possesses anti-anaphylactic effect in cardiovascular system.

• 한국가시화정보학회지
• /
• 제15권2호
• /
• pp.41-47
• /
• 2017

Microring/nanoring structure has high applicability for nano-antenna and biosensor thanks to its superior optical characteristics. Although coiling nanowires manufactured using immiscible emulsion droplets have an advantage in mass production, this process also forms nanowire bundles. In this study, we solved the nanowire bundle problem by size-selective sorting of the emulsion droplets in a pinched flow fractionation microchannel. Utilizing silver nanowires and immiscible emsulsion droplets, we investigated the correlation between the size of ring droplets and bundle droplet. We visualized the sorting process for glass particles and microring-containing emulsion droplets. Droplets were sorted based on their size, and the ratio of bundle droplets in solution decreased. This droplet-sorting strategy has potential to help the printing and coating process for manufacturing of ring structure patterns and developing of functional materials.

• 한국축산식품학회지
• /
• 제38권4호
• /
• pp.693-702
• /
• 2018

The purpose of this study was to develop a commercially viable method for synthesis of conjugated linoleic acid (CLA) using the linoleic acid fraction obtained from six pork by-products (liver, lung, heart, stomach, small intestine, and large intestine). The workflow of CLA synthesis from each by-product was as follows: washing${\rightarrow}$crude fat extraction${\rightarrow}$fractionation into saturated and unsaturated fatty acids${\rightarrow}$repeat unsaturated fatty acid fractionation${\rightarrow}$CLA synthesis. Cis-9, trans-11, and trans-10, cis-12 CLA was synthesized from pork by-products. The yield of CLA synthesis of pork by-products ranged from 1.55 to 11.18 g per 100 g of by-products. The amount of synthesized CLA was the highest in the small intestine and large intestine by-products. Fractionation of pork by-products nearly doubled the yield of CLA. We suggest that commercial fractionation methods could increase the yield of CLA at low cost, reduce waste, and improve the efficiency of by-product utilization.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권1호
• /
• pp.65-68
• /
• 2004

The purpose of the present study was to examine the efficacy and mechanism of fraction IV cold ethanol fractionation and pasteurization (60$^{\circ}C$ heat treatment for 10 h), involved in the manufacture of albumin from human plasma, in the removal and/or inactivation of the hepatitis A virus (HAV). Samples from the relevant stages of the production process were spiked with HAV and the amount of virus in each fraction then quantified using a 50% tissue culture infectious dose (TCID$\_$50/). HAV was effectively partitioned from albumin during the fraction IV cold ethanol fractionation with a log reduction factor of 3.43. Pasteurization was also found to be a robust and effective step in inactivating HAV, where the titers were reduced from an initial titer of 7.60 log TCID$\_$50/ to undetectable levels within 5 h of treatment. The log reduction factor achieved during pasteurization was $\geq$4.76. Therefore, the current results indicate that the production process for albumin has sufficient HAV reducing capacity to achieve a high margin of virus safety.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제18권3호
• /
• pp.1-10
• /
• 2013

This study was performed to summarize application of ${\delta}^{13}C$, ${\delta}^{37}Cl$ and ${\delta}D$ of trichloroethylene (TCE) to studies on environmental forensic field regarding identification of TCE sources and evaluation of contribution of TCE to groundwater using data collected from literatures. ${\delta}^{13}C$, ${\delta}^{37}Cl$ and ${\delta}D$ of TCE give some information regarding sources of TCE because they show specific value according to manufacturing method. Also, TCE do not show a significant isotopic fractionation owing to adsorption and dilution. The isotopic fractionation mainly occurs by biodegradation. In addition, isotopic fractionation factor for TCE is different according to a kind of microorganism participated in biodegradation. However, the isotopic data of TCE have to be applied with chemical compositions of TCE and other hydrogeologic factors because isotopic fractionation of TCE is influenced by various factors.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제16권4호
• /
• pp.10-22
• /
• 2011

Human health risk assessment for petroleum, oil and lubricant (POL) contaminated sites is challenging as total petroleum hydrocarbon (TPH) is not a single compound but rather a mixture of numerous substances. To address this concern, several TPH fractionation approaches have been proposed and used as an effective management tool for the POL-contaminated sites in many countries. In Korea, there are also recognized needs to establish a reliable and cost-effective human health risk assessment strategy based on the TPH fractionation method. In order to satisfy the social and institutional demand, this study suggested that the comprehensive risk assessment strategy based on a newly modified TPH fractionation method with 10 fractions, the Korean Standard Test Method (KSTM)-based analytical protocol and a stepwise risk assessment framework should be introduced into the domestic contaminated land management system. Under the proposed strategy, POL-contaminated sites can be effectively managed in terms of human health protection, and remedial cost and time can be determined reasonably. In addition, more researches required to increase our understanding of environmental risks and improve the domestic management system were proposed.

• 한국토양비료학회지
• /
• 제40권4호
• /
• pp.326-329
• /
• 2007

Quantifying soil organic carbon (SOC) has long been considered to improve our understanding of soil productivity, soil carbon dynamics, and soil quality. And also SOC could contribute as a major soil management factor for prescribing fertilizers and controlling of soil erosion and runoff. Reducing tillage intensity has been recommended to sequester SOC into soil. On the other hand, determination of traditional SOC could barely identify the tillage practices effect. Physical soil fractionation has been reported to improve interpretation of soil tillage practices impact on SOC dynamics. However, most of these researches were focused onupland soils and few researches were conducted on paddy soils. Therefore, the objective of this research was to evaluate paddy soil tillage impact on SOC by physical soil fractionation. Soils were sampled in conventional-tillage (CT), partial-tillage (PT), no-tillage (NT), and shallow-tillage (ST)plots at the National Institute of Crop Science research farm. Samples were obtained at the three sampling depth with 7.5-cm increment from the surface and were sieved with 0.25- and 0.053-mm screen. Soil organic carbon was determined by wet combustion method. Significant difference of SOC contentwas found among sampling soil depth and soil particle size. SOC content tended to increase at the ST plot with increasing size of soil particle fraction. We conclude that quantifying soil organic carbon by physical soil particle fractionation could improve understanding of SOC dynamics by soil tillage practices.

• 상하수도학회지
• /
• 제24권4호
• /
• pp.387-394
• /
• 2010

The influent COD of municipal wastewater has been divided into 4 fractions; readily soluble biodegradable, slowly particulate biodegradable, soluble and particulate unbiodegradable COD. The mathematical modeling of biological wastewater treatment processes and the design and operation of nutrient removal plants require a reliable and accurate estimate of the composition of influent wastewater COD. COD utilization rate is proportional to the oxygen uptake rate(OUR), so a batch biodegradation test with OUR measurement has been effectively used for the determination of COD fractionation. But the mathematical model of COD utilization and heterotrophs synthesis is essential to interpret the OUR measurement. Mamais method is another method for determining readily biodegradable soluble COD. Like the OUR test method, batch biodegradation test is necessary but it does not require mathematical model. These two methods for determining COD fractionation are introduced here in detail. Experimental results showed that COD composition by Mamais method is not different to that by OUR test method so, either of them can be used.

• 펄프종이기술
• /
• 제32권4호
• /
• pp.27-33
• /
• 2000

A new technique for fractionating pulp stock into a long fiber portion and fines fraction was developed by KRICT in order to enhance the drainage and strength properties of recycled OCC pulp. In order to investigate the effect of fines contents in stock and stages of flotation on fractionation efficiency, flotations were performed at varied fines contents and flotation stages. Based on the result of multi-stage flotation fractionation it could be said that fines smaller than 15${\mu}{\textrm}{m}$ stabilize flotation froth of OCC. Although the amounts and the fines contents of flotation reject could be increased by multi-stage flotation fractionation of OCC, flotation stages more than 3 times were found to be inefficient in terms of fines concentrating degree. In order to satisfy the both conditions of reducing long fiber loss and of increasing flotation reject, several kinds of fractionating promoters were searched and investigated. And high molecular weight cationic polyacrylamide was chosen as a long fiber flocculating and flotation froth-stabilizing agent.