• Food Science and Biotechnology
• /
• 제18권4호
• /
• pp.978-984
• /
• 2009

An analytical method for the simultaneous determination of 9 quinolones (QNs) in porcine, chicken, and bovine muscles was developed and validated using liquid chromatography-fluorescence detector (LC-FLD). The samples were extracted using a liquid-liquid extraction (LLE) process. Chromatographic separation was achieved on a reverse phase $C_8$ column with a gradient elution using a mobile phase of 200 mM ammonium acetate buffer (pH 4.5) and acetonitrile (ACN). The proposed method was validated according to the Food and Drug Administration (FDA) guideline for bioanalytical assay procedures. Recoveries of QNs were 83.1-111.9% with relative standard deviations (RSDs) below 15%. Linearity within a range of 30-500 ${\mu}g/kg$ was obtained with the correlation coefficient ($R^2$) of 0.9967-0.9999. The limits of detection (LOD) were 1-16 ${\mu}g/kg$. These values were lower than the maximum residues limits (MRLs) established by the European Union (EU). The present method was successfully applied to determine QNs in edible muscles.

• Food Science and Biotechnology
• /
• 제18권5호
• /
• pp.1124-1131
• /
• 2009

Acanthopanax senticosus has been used in East Asia as a traditional medicine. The purpose of this study is the investigation of an extraction method for A. senticosus var subinermis (ASvS) leaves to improve their antioxidant and anti-inflammatory activities. Six extracts were prepared: extracted with water (W), ethanol (Eth), water or ethanol after ultra high pressure (WP, EthP), and water or ethanol after an extrusion process (WEx, EthEx). Diphenylpicrylhydrazyl (DPPH) radical scavenging activity and ferric reducing ability showed that all extracts had a significant antioxidant activity. In anti-inflammatory activities, Eth and EthEx significantly inhibited the release of lipopolysaccharide (LPS)-induced nitric oxide (NO), tumor necrosis factor (TNF)-${\alpha}$, and interleukin (IL)-$1{\beta}$ independent of cell viability in RAW 264.7 macrophage cells. Inducible NO synthase (iNOS) protein was significantly decreased by EthEx. These findings present that Eth and EthEx extracts of ASvS leaves have anti-inflammatory activities, and EthEx extract suppresses LPS-induced NO through the down-regulation of iNOS and pro-inflammatory cytokines.

• 한국식품영양과학회지
• /
• 제23권2호
• /
• pp.225-231
• /
• 1994

As the way of mass process of red pepper, extraction of oleoresin, which is labile during distribtuion and long-term storage, is alternative way to minimize markdown of red pepper quality. Changes of carotenoid pigments in modified oleoresin during cooking at high temperature were investigated. Dried red peperwas milled to 100 mesh of size particle and oily compounds were extracted by reduced pressure steam distillation. The rest part was reetracted and concentrated. The extracts were combined . The same volume of water and 4 % of polyglycerol condensed ricinoleate (PGDR) were added to the combined extract, and emulsified to make oleroesin. Capsanthin among dried red pepper, was the most abundant carotenoid (97.80mg%) followed by $\beta$ -cartoene, cryptoxanghin ,violaxanthin, crypotocapsin, and capsorubin. Oleoresin is acquiesce in the same order of raw red pepper. Transmittal of color components from raw red pepper to oleroresin was over 85% in cryptoxanthin, crytocapsin, and $\beta$ -carotene, over 70% in capsolutein and hydroxycapsolutein, and under 50% in antheraxanthin and mutatoxanthi Crytocapsin cryptoxanthin, an capsorubin in oleoresin red pepper were remained 72.1, 51.8 and 25.25, respectively, after cooking for 5hours at10$0^{\circ}C$. Color compounds were unsteady by cooking , About 90% of color compounds were destroyed by 3 hours cooking at 15$0^{\circ}C$. But, they were more thermostable under nitrogen circumstance than air one.

• 한국기계가공학회지
• /
• 제21권5호
• /
• pp.98-104
• /
• 2022

When processing parts, the cutting oil can improve the cooling performance of the workpiece and tool to increase the precision of the workpiece or extend the life of the tool and facilitate chip extraction. Since such cutting oil has a harmful effect on the environment and the human body due to additives such as sulfur, research on a minimum lubrication supply method using an eco-friendly oil is recently underway. The minimum lubrication supply method minimizes the amount of cutting oil used during processing and processes it, which can reduce the amount of cutting oil used, but has a problem in that cooling performance efficiency is poor. Therefore, this study conducted a study on mist cooling of lubricants to reduce the amount of cutting oil used and maximize the cooling effect of processing heat generated during tapping processing. Spray pressure, processing speed, direction, and lubricant spray amount, which are considered to have an effect on cooling performance, were set as process conditions, and the effect on temperature was analyzed by performing an experiment using the box benquin method among experiments were analyzed. Through the experimental analysis results, the optimal conditions for mist and processing that maximize the cooling effect were derived, and the validity of the results derived through additional experiments was verified. In the case of processing by applying the mist lubrication method verified through this study, it is considered that high-precision processing is possible by improving the cooling effect.

• 한국수산과학회지
• /
• 제34권3호
• /
• pp.213-217
• /
• 2001

동결 건조된 미역 가공 부산물로부터 색소 및 지방산의 추출 및 조건은 시료 30g, 압력 $10.3\~17.2MPa$, 유량 15mL/min와 온도 $30\~45^{\circ}C$에서 추출 실험을 실시하였다. 지방산의 경우 초임계 처리하지 않은 것에 비해 불포화 지방산의 함량이 높게 나타났고, 온도 $40^{\circ}C$의 조건에서 보조용매 (entrainer)로 에탄올을 첨가하여 압력의 변화에 따른 회수율을 실험한 결과 12.4MPa에서 최대 $92\%$의 회수율을 보였다. 그리고 압력이 증가하면서 초임계 이산화탄소에 대한 용질의 용해도가 감소하는 retrograde 현상이 나타났다 시료입자의 크기를 $500\~1,000{\mu}\;m$와 12.4MPa에서 온도의 변화를 주어 실험한 결과 입자의 크기 $500{\mu}m$가 $1000{\mu}m$에 비해 색소의 추출량이 1.8배정도 많았다 최적 조건 (압력 12.4MPa,온도 $35^{\circ}C$, 입자크기 $500{\mu}m$)에서 추출시간에 따른 chlorophyll a 함량을 비교한 결과 에탄올을 각각 3mL/min, 5mL/min 첨가하였을 때 모두 20분까지 함량이 증가한 후 감소하였으며, 최적 추출시간은 30분까지로 판단되었다. 유기용매 추출과 초임계 추출을 비교한 결과 유기용매로 48시간 추출시 chlorophyll a 함량이 150mg/L였지만 초임계로 1시간 추출시 최대 172mg/L로 약 $20\%$ 증가하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
• /
• pp.169-169
• /
• 2008

To keep pace with scaling trends of CMOS technologies, high-k metal oxides are to be introduced. Due to their high permittivity, high-k materials can achieve the required capacitance with stacks of higher physical thickness to reduce the leakage current through the scaled gate oxide, which make it become much more promising materials to instead of $SiO_2$. As further studying on high-k, an understanding of the relation between the etch characteristics of high-k dielectric materials and plasma properties is required for the low damaged removal process to match standard processing procedure. There are some reports on the dry etching of different high-k materials in ICP and ECR plasma with various plasma parameters, such as different gas combinations ($Cl_2$, $Cl_2/BCl_3$, $Cl_2$/Ar, $SF_6$/Ar, and $CH_4/H_2$/Ar etc). Understanding of the complex behavior of particles at surfaces requires detailed knowledge of both macroscopic and microscopic processes that take place; also certain processes depend critically on temperature and gas pressure. The choice of $BCl_3$ as the chemically active gas results from the fact that it is widely used for the etching o the materials covered by the native oxides due to the effective extraction of oxygen in the form of $BCl_xO_y$ compounds. In this study, the surface reactions and the etch rate of $Al_2O_3$ films in $BCl_3/Cl_2$/Ar plasma were investigated in an inductively coupled plasma(ICP) reactor in terms of the gas mixing ratio, RF power, DC bias and chamber pressure. The variations of relative volume densities for the particles were measured with optical emission spectroscopy (OES). The surface imagination was measured by AFM and SEM. The chemical states of film was investigated using X-ray photoelectron spectroscopy (XPS), which confirmed the existence of nonvolatile etch byproducts.

• 한국분말재료학회지
• /
• 제1권1호
• /
• pp.72-78
• /
• 1994

Two kinds of $U_3Si$ powders and $U_3Si$ dispersed nuclear fuel meats have been prepared by conventional comminution process and a newly developed rotating disk atomization process. In contrast to angular shape and broad size distribution of the conventionally processed powder, the atomized powder was spherical and showed narrow size distribution. For the atomized powder, the heat treatment time for the formation of $U_3Si$ by a peritectoid reaction was reduced to about one tenth, thanks to microstructure refinement by rapid cooling of about 5$\times$104 K/s. The extruding pressure of atomized $U_3Si$ powder and Al powder mixture was lower than that of comminuted $U_3Si$ and Al powder mixture. The elongation of the atomization processed fuel meats was much higher than that of the comminution processed fuel meats and remained over 10% up to 80wt.% of $U_3Si$ powder fraction in the fuel meats. It appears therefore that the loading density of $U_3Si$ in fuel meat can be increased by using atomized $U_3Si$ powder. The atomized spherical particles were randomly distributed, while the comminuted particles with angular and longish shape were considerably aligned along the extrusion direction. Along the transverse direction of the extraction the electrical conductivity of the atomization processed fuel meats was appreciably higher than that of comminution processed fuel meats. This tendency became pronounced as $U_3Si$ content increased. Because the thermal conduction which is believed to be proportioned to the electrical conduction in the nuclear fuel meats occurs in radial direction, the atomization processed fuel can be better used in research reactors where high thermal conductivity is required.

• Korean Chemical Engineering Research
• /
• 제54권4호
• /
• pp.443-447
• /
• 2016

미세조류 세포벽은 셀룰로오스가 주요 구성성분으로 리그닌을 포함하지 않아 낮은 온도의 전처리 조건에서도 효과적으로 셀룰로오스와 헤미셀룰로오스 분해가 가능하다. 차세대 바이오매스로 주목 받는 미세조류(Tetraselmis KCTC 12236BP)로부터 $120^{\circ}C$ 이하의 낮은 온도 조건에서 열수전처리를 이용한 발효당 생산 증대를 위해 공정조건을 최적화하였다. 주요 공정조건인 추출온도, 황산농도와 추출시간에 따른 당화율 변화를 확인하였을 때, 온도와 황산농도가 글루코오스 생산에 큰 영향을 컸으며 당화율이 비례하여 증가하는 경향을 보였다. 경제성을 고려한 열수전처리 최적조건은 $120^{\circ}C$, 2 mol 황산, 40분으로 95.9%의 당화율을 얻을 수 있었다. 탈지미세조류의 황산 열수전처리와 효소당화를 비교했을 때, 황산 열수전처리의 당화율이 2.1배 이상 높고 전처리 시간이 짧아 황산 열수전처리가 효소당화에 비해 효과적인 공정임을 확인하였다.

• Journal of the Korean Wood Science and Technology
• /
• 제7권2호
• /
• pp.3-30
• /
• 1979

우리나라에서는 일본잎갈나무가 대량(大量) 조림(造林)되어 축적(蓄積)과 생장량(生長量)으로 보아 주요(主要)한 조림(造林) 수종(樹種)이나 각종(各種) 추출물(抽出物)과 활성(活性) phenol 성분(成分)이 많고 심재율(心材率)이 높아 펄프화(化)에서 수율저하(收率低下)와 표백곤란(漂白困難)이 초래(招來)되어 펄프원료(原料)로서의 이용(利用)이 기피(忌避)되고 있다. 따라서 일본잎갈나무의 화학(化學)펄프 원료화(原料化)의 제고(提高)로서 펄프수율(收率) 향상(向上)과 표백성(漂白性) 개선(改善)을 위하여 셀룰로오스보호제를 첨가(添加)한 소다펄프화(化) 특성(特性)을 구명(究明)하였다. 증해(蒸解)는 최고온도(最高溫度) 170$^{\circ}C$까지 90분간(分間) 가열(加熱)하고 90분간(分間) 유지(維持)하는 일정조건(一定條件)으로 황화도(黃化度) 25%, 활성(活性)알칼리 18%의 크라프트법(法)으로 일본잎갈나무의 수령별(樹齡別) 펄프화(化) 특성(特性)을 구명(究明)하고, 18%활성(活性) 알칼리의 소다증해(蒸解)에 첨가제로 2.5% $MgSO_4$, 2.5% $ZnSO_4$, 2.5% $Al_2(SO_4)_3$, 2.5% KI, 2.5% hydroquinone, 2.5% ethylene diamine 또는 0.1~1.0% anthraquinone를 가(加)하여 15년생(年生) 일본잎갈나무의 변재(邊材)와 심재별(心材別) 소다펄프화(化) 특성(特性)을 구명(究明)한 후(後), 0.5% anthraquinone과 18% 활성(活性)알칼리로 증해(蒸解)된 펄프를 3%, 6%, 9% NaOH를 투입(投入)한 30%의 고농도(高農度)펄프를 상압(常壓) 산소표백(酸素漂白)하고, 이산화염소(二酸化鹽素)의 DED로 계속표백(繼續漂白)한 결과(結果) 다음과 같은 결론(結論)을 얻었다. 1. 일본잎갈나무의 수령별(樹齡別) 크라프트펄프는 수령간(樹齡間)에 펄프의 정선수율(精選收率)은 차(差)가 없으나, 수령(樹齡)이 증가함에 따라 펄프의 총수율(總收率)은 감소(減少)하고 비인열도(比引裂度)는 증가하였으며, 목재(木材)의 심재율(心材率), 용적밀도(容積密度) 수(數), 섬유장(纖維長) 및 온수추출물(溫水抽出物)도 증가하는 경향(傾向)을 나타냈다. 2. 일본잎갈나무의 변재(邊材)와 심재별(心材別) 소다증해(蒸解)에 셀룰로오스 보호제로 첨가(添加)된 7종(種)의 첨가제들은 변재(邊材)와 심재(心材)펄프화(化)에 대한 영향(影響)이 대체로 소다법(法)보다 증가되었으나 크라프트법(法)에 미치지 못하고, 크라프트펄프법(法)에 가까운 첨가제는 펄프수율(收率)에서 KI $MgSO_4$, anthraquinone이며, 특(特)히 다른 첨가제의 25분(分) 1이 첨가(添加)된 anthraquinone은 펄프의 정선수율(精選收率)과 KappaNo. 및 비파열도(比破裂度)에서 다른 첨가제보다 효과적이었다. 3. anthraquinone첨가량(添加量)에 따른 변재(邊材)와 심재별(心材別) 소다펄프의 품질(品質)은 변재(邊材)와 심재(心材) 모두 첨가량(添加量)이 많을수록 탈(脫)리그닌도(度)와 펄프수율(收率)이 높으나 활성(活性)알칼리가 낮으면 정선수율(精選收率)도 낮았으며 활성(活性)알칼리 17%의 소다 증해액(蒸解液)에 0.5% anthraquinone을 첨가(添加)한 조건(條件)에서는 크라프트펄프보다 비교적(比較的) 양호(良好)한 펄프가 얻어졌다. 4. 일반화(一般化)된 CEDED표백중(漂白中) 염소화(鹽素化)와 알칼리 추출단계(抽出段階) 대신(代身)에 30%의 고농도(高濃度)펄프에 상압(常壓) 산소표백(酸素漂白)한 ODED표백(漂白)은 산소단계(酸素段階)에서 변재(邊材)와 심재(心材)펄프 모두 NaOH투입량(投入量)이 증가될수록 백색도(白色度)와 비인열도(比引裂度)가 향상(向上)되나 펄프수율(收率)과 Kapa No.는 감소(減少)되었으며, NaOH 투입량(投入量)이 높을수록 펄프품질(品質)은 CEDED 표백(漂白)과 유사(類似)하나 펄프수율(收率)이 떨어졌다. 5. 따라서 본(本) 실험(實驗)에서는 펄프수율(收率) 향상(向上)을 위해서는 원료(原料)에서 심재율(心材率)이 낮은 수령(樹齡)의 경우가 펄프재(材)로 적당(適當)하고, 0.5% anthraquinone을 첨가(添加)한 활성(活性)알카리 18%의 소다증해(蒸解)하는 것이 적당(適當)하며 폐수중(廢水中)의 염소화합물(鹽素化合物)을 감소(減少)시키기 위하여서는 펄프농도(濃度) 30%이상(以上)의 고농도(高濃度)에서 상압(常壓) 산소(酸素)로 표백후(漂白後) 이산화(二酸化) 염소(鹽素)로 DED 표백(漂白)하면 일본잎갈나무의 크라프트법(法)보다 비교적(比較的) 우수(優秀)한 펄프를 얻을 수 있다.