• 제목/요약/키워드: extracting methods

검색결과 947건 처리시간 0.033초

Efficiency for extracting icariin from Epimedium koreanum Nakai by temperature and solvent variations

  • Baek, Hum-Young;Lee, Young-Sang
    • Plant Resources
    • /
    • 제6권3호
    • /
    • pp.221-226
    • /
    • 2003
  • To improve industrial scale extraction method for extraction of icariin from Epimedium koreanum Nakai, the yields under different extracting conditions such as solvent, temperature, duration and solvent to plant material weight ratio were compared. Regarding extracting solution, highest extracts and icariin yield could be achieved when 10% EtOH was used. In case of plant material to extracting solvent ratio, no significant differences could be observed from 1/10 to 1/50, indicating 1/10 was the most efficient. Extracting temperature significantly affected extracts and icariin yields in that 9$0^{\circ}C$ increased the collected extracts and icariin contents up to 29.6% and 0.76%, respectively, compared to 27.2%, 0.33% at 7$0^{\circ}C$. The yield of extracts was less dependent upon extracting temperature compared to icariin yield. Regarding extraction time, 4 hr and 6 hr resulted in high extracts and icariin yield, respectively. We found extracting Epimedium koreanum Nakai in 10 times volume of 10% EtOH for 4 and 6 hr at 9$0^{\circ}C$ seem to be relatively efficient methods for extracts and icariin, respectively.

  • PDF

투석과 건조방법이 다시마(Laminaria japonica) 알긴산의 물성에 미치는 영향 (Effects of Dialysis and Various Drying Methods on Physical Properties of Alginates Prepared from Sea Tangle, Laminaria japonica)

  • 임영선;유병진
    • 한국수산과학회지
    • /
    • 제38권4호
    • /
    • pp.226-231
    • /
    • 2005
  • To investigate the physical properties of sea tangle (Laminaria japonica) alginates, extracted by the Mexican process, the effects of extracting time and drying methods on intrinsic viscosities, MWs and DPs of alginates were examined. The MWs of alginates before and after dialysis decreased with increase of extracting time. The MW s before dialysis were lower than those after dialysis. The ash contents before dialysis decreased with increase of extracting time. After dialysis the ash contents of the alginates showed 10.4-10.9% of those, which were little affected by extracting time. In the ash composition after dialysis, the sodium content was 4.4 g/100 g, $90\%$ of total ash content. The ash contents, the intrinsic viscosities, the average molecular weight and the DPs of the alginates dried by AD before dialysis were higher than those by VF. The ash and uronic acid contents of alginates after dialysis showed $10.6-10.9\%\;and\l88.1-88.9\%$, respectively. But the intrinsic viscosities, the MWs and DPs of the alginates after dialysis gradually decreased by following dry methods. The decreased order was ADAD, ADVF, VFAD, VFVF. The coefficient of determination between MWs and DPs in the alginates having more than 300 kDa was 0.999.

Survey of Temporal Information Extraction

  • Lim, Chae-Gyun;Jeong, Young-Seob;Choi, Ho-Jin
    • Journal of Information Processing Systems
    • /
    • 제15권4호
    • /
    • pp.931-956
    • /
    • 2019
  • Documents contain information that can be used for various applications, such as question answering (QA) system, information retrieval (IR) system, and recommendation system. To use the information, it is necessary to develop a method of extracting such information from the documents written in a form of natural language. There are several kinds of the information (e.g., temporal information, spatial information, semantic role information), where different kinds of information will be extracted with different methods. In this paper, the existing studies about the methods of extracting the temporal information are reported and several related issues are discussed. The issues are about the task boundary of the temporal information extraction, the history of the annotation languages and shared tasks, the research issues, the applications using the temporal information, and evaluation metrics. Although the history of the tasks of temporal information extraction is not long, there have been many studies that tried various methods. This paper gives which approach is known to be the better way of extracting a particular part of the temporal information, and also provides a future research direction.

용접흄내 중금속분석시 전처리 방법별 효율비교 (A Comparison of Efficiency of Two Pretreatment Methods for Extracting Heavy Metals from Welding Fume Samples)

  • 손두영;김현욱
    • 한국산업보건학회지
    • /
    • 제9권2호
    • /
    • pp.135-144
    • /
    • 1999
  • The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.

  • PDF

양파의 Quercetin 관련 물질의 분리 기술 개발 2. 양파의 Quercetin 물질의 최적 추출조건 (Development of Separating Techniques on Quercetin-Related Substances in Onion(Allium cepa L.) 2. Optimal Extracting Condition of quercertin-Related Substances in Onion)

  • 강성구;김용두;현규환;김영환;서재신;박양균
    • 한국식품영양과학회지
    • /
    • 제27권4호
    • /
    • pp.687-692
    • /
    • 1998
  • To use onion(Allium cepa L.) residue as raw materials of food product, yields of onion-juice according to various extracting methods and optimal extracting condition of quercetin and its related glycosides were carried out. Onion juices gained by the methods of pressing, rotary crushing, freeze pressing and enzyme treatment. The yield by the method of enzyme treatment was higher than others. The yields of juice from fresh onion and heat-treated onion(8$0^{\circ}C$/10min) by pressing were 66% and 83%, respectively. Ethanol extraction of onion was efficient at 75$^{\circ}C$ and acetic acid extraction was proper at 3% concentration for 3 hours at 11$0^{\circ}C$. The onion extract was fractionated in the order of hexane, chloroform, ethylacetate and butanol to test flavonoids. The highest abundant flavonoids were found in ethylacetate and butanol fraction.

  • PDF

A Study on Concept Generation and Development for Street Furniture Design through Extracting Design Factors from the Space Design

  • In, Chi-Ho
    • 한국가구학회지
    • /
    • 제22권3호
    • /
    • pp.183-189
    • /
    • 2011
  • This is a study on methods for designers of furniture and products to generate and develop design concept in consideration of design and existing conditions of the space when they design street furniture. In particular, in case when they participate in a process of designing new space, this study aims to reveal methods generating strategic elements and basic ideas for designing street furniture through cases study of projects by understanding and analyzing concept of overall space design and by extracting artistic elements for deployment of specific designs. First, Design DNA, which decides overall flow of design concept of street furniture, is extracted through analyses of basic concepts of space design. Next, by applying 3V Design Process, alternatives of the concept generation are suggested through methods of storytelling and design language under the two approach methods of verbalization stage and visualization stage. Also its methods were explored through suggestion of designs by developing each idea of the respective concepts into specific design vocabulary.

  • PDF

계내김(鷄內金)에서 추출한 protease를 이용한 녹용(鹿茸) 추출 특성 연구 (A study on the extracting characteristics of velvet antlers using kyenegum protease)

  • 박재호;김도완
    • 대한본초학회지
    • /
    • 제26권4호
    • /
    • pp.89-94
    • /
    • 2011
  • Objective : Kyenegum has been frequently used for characterizing digestive symptoms in the traditional and oriental medicines. This study was conducted to investigate the characteristics of extracts from velvet antlers using the 4 different kinds of extracting methods. Methods : The extracts of velvet antlers were extracted using a $65^{\circ}C$ DW (9hrs), a Kyenegum crude enzyme, a $121^{\circ}C$ DW (2hrs), and a Kyenegum protease. To evaluate the characteristic of velvet antler extracts, we examined the brix, soluble solid, amino acid, mineral composition, and collagen protein. Results : As a result of the comparisons of velvet antlers extracted by the traditional extraction and the crude enzyme of kyenegum, the brix and soluble solid showed the higher contents for kyenegum enzymes. Also, mineral contents of the extracted velvet antlers were higher, particularly in Ca and P for those. The contents of collagen protein, hydroxyproline and hydroxylysine, were found to be more than twice in kyenegum protease compared with other extracting methods. Conclusion : These results indicated that the Kyenegum crude enzyme and protease are very effective to extract of velvet antlers.

Extraction Methods of Organic Components from Rubber Composites and Analysis of the Extract Using Gas Chromatography/Mass Spectrometry

  • Chae, Eunji;Choi, Sung-Seen
    • Elastomers and Composites
    • /
    • 제54권3호
    • /
    • pp.188-200
    • /
    • 2019
  • Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

그레이스케일 히스토그램을 이용한 에지의 수평 정보획득 영상검색 (Gray scale image histogram using the horizontal edge information search)

  • 정일회;박종안
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2008년도 춘계종합학술대회 A
    • /
    • pp.151-154
    • /
    • 2008
  • 본 논문은 현 검색시스템의 단순한 키워드 입력 방식에서 발생하는 오차를 줄이기 위해 이미지의 그레이스케일 히스토그램과 에지정보를 이용하는 검색 시스템 구현을 하였다. 검색알고리즘은 질의 이미지의 특징을 추출하는 단계, 이미지 정제 및 에지정보 추출단계, 추출된 특징을 분석하는 단계, 분석된 특징들로부터 필요한 정보를 확보하는 단계, 확보된 정보를 데이터베이스로부터 검색하는 단계, 검색된 데이터베이스에서 이미지를 비교 추출단계로 이루어진다. 제안한 검색시스템은 빠른 검색과 고 정확도를 목적으로 실현되며 시뮬레이션을 통해 이를 검증하고자 하였다.

  • PDF