• Membrane and Water Treatment
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• 제8권1호
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• pp.19-34
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• 2017

Boron exists in dilute concentrations in sea water, ground water and waste waters. Reactive liquid extraction can be used for removing boron to make the treated water suitable for drinking and irrigation, with its final concentration less than 0.5 ppm. The results of equilibrium experiments are reported on the removal of boron using 2-butyl-2-ethyl-1, 3-propanediol (BEPD as a nonionic carrier) in sunflower oil, a non-traditional solvent. The results of removal of boron from aqueous solutions in the concentration range 0.5-20 ppm are presented. It is shown that this new liquid membrane system, is able to remove boron from ground waters at their natural pH of 6-8 (without any chemical addition for pH adjustments). The removal efficiency is good when the process is upgraded to a hollow-fibre membrane contactor and approximately 45% boron can be removed in a single-stage contact. There are additional advantages of this new approach that includes reduced operational health and safety and environmental issues. The results reported here provide guidelines to the development of boron removal process using renewable, biodegradable, safe and cheap solvent system such as sunflower oil.

• Membrane and Water Treatment
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• 제4권2호
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• pp.95-108
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• 2013

Metal ions exist in seawater, groundwater and industrial wastewaters. These source waters can be recycled if their concentrations are reduced. A number of processes can be applied for this purpose. Liquid-liquid extraction is one of the promising methods. In this paper, experimental results are presented on the removal of Cr(VI) using Aliquat-336, a reactive carrier, in sunflower oil (a non-toxic solvent). The performance of this new system is compared with those of kerosene (a toxic solvent). The extent of removal of Cr(VI) from samples with high and low concentrations are presented. The process was upgraded to a bench-scale module that can selectively remove about 50-90% Cr(VI) from samples of groundwater. Thus this process can produce water within the acceptable range for recycling and for use in secondary purposes such as irrigation.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.143-145
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• 1998

식품공업 분야에서 특정 성분의 분리, 정제, 농축은 매우 중요한 단위공정으로써 추출(Extraction), 여과(Filtration), 증류(Distillation), 증발(Evaporation)등의 조작을 통하여 실시되고 있다. 최근 들어 화학공업, 기계공업, 식품공업의 지속적인 발전에 힘입어 단위조작을 효율적으로 실시할 수 있는 기술로써 국내의 산업화되고 있는 것이 분리막 기술이다. 현재 식품공업 분야에서 활용되고 있는 분리막공정의 종류는 정밀여과(Microfiltration), 한외여과(Ultrafiltration), 초정밀여과(Nanofiltration), 역삼투(Reverse Osmosis) 시스템으로 유제품, 조미료, 음료공업, 장유산업, 기능성 인자의 분리 등에 공업적으로 점차 그 도입 가능성이 증가하고 있다.

• 대한의용생체공학회:의공학회지
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• 제30권4호
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• pp.311-317
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• 2009

An automatic control system is proposed and implemented for a miniaturized DNA extraction system using magnetic bead. A host-local system is employed for the accommodation of the graphical user interface and the basic control function. The functional partitioning into the local and the host system is discussed. The control functions are classified and formalized for the flexible control scenario, which is the input of the proposed system. As the proposed scenario is consists of the sequence of the user-centric actions, the user goal can be easily programmed and modified. The DNA extraction performance of the implemented system was compared with the existing silica-membrane-based method, resulting in the comparable concentration and purity of the extracted DNA. The proposed system is currently being utilized for the development of the DNA extraction system only changing scenario, without any alteration of the system.

• 기술사
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• 제32권2호
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• pp.99-109
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• 1999

The dried sea tangle added for soup prepatation to improved the taste in Korean and Japaness for long time. Attempts were made to develop the best procedures for extraction and removal of alginate by ultrafiltration and diafiltration. The summerized results of this study are as follows: 1) For hot water extraction in temperature range of 60～100$^{\circ}C$ for 4 hours, the higher temperature resulted higher yields in solids and protein. 2) Optimum sea tangle hot water extraction condition were 60～65$^{\circ}C$ for 1 hour which was cheap operating cost and high yield of good taste components. 3) The membrane flux was more higher GR 51 PP. and increase of flow rate permeate flow rate was accordingly increased. but limiting flow volume was 3.7 l/min. 4) It was found that ultration was relatively of higher recovery rate, solid and taste components, and low rejection coefficient rate than diafiltration.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.49-55
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• 2007

Three kind of ASE (Accelerated Solvent Extraction) and SPMDs (Semi-Permeable Membrane Devices) combined methods (ASE-SPMDs, ASE-accelerated SPMDs and SPMDs without extraction) and general Soxhlet-GPC were compared each other for the analysis of PCDD/FS in sediment. The average recovery rate of three types ASE and SPMDs combined methods (108.1%) were higher than that of the Soxhlet-GPC (79.5%) for three samples in each method using surrogate internal standards. The average coefficient of variation (10%, $2.1{\sim}25.2%$) for each congener of PCDD/Fs shows the reasonable results. Total PCDD/Fs concentrations after SPMDs without extraction were quite low, but those after ASE-SPMDs and ASE-accelerated SPMDs methods were close to the Soxhlet-GPC. Thus, the ASE-SPMDs and ASE-accelerated SPMDs methods are considered as the excellent pre-treatments method because they need less solvent and time without quality degradation.

• Journal of Periodontal and Implant Science
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• 제51권4호
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• pp.285-295
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• 2021

Purpose: The aims of the present study were 1) to quantitatively evaluate the extent of sinus pneumatization and 2) to determine the factors affecting sinus pneumatization. Methods: Based on implant treatment records, a list of patients who underwent implant placement on the posterior maxilla was obtained. Among them, patients with pre-extraction and post-extraction (before implant placement) panoramic radiographs were selected. After excluding radiographs with low resolution and image distortion, the radiographs before and after extraction were superimposed using computer software. Subsequently, the extent of sinus pneumatization (the vertical change of the sinus floor) was measured. Simple and multiple mixed models were used to determine the factors affecting sinus pneumatization. Results: A total of 145 patients were eligible for the present investigation. The average extent of sinus pneumatization was 1.56±3.93 mm at 176 tooth sites. Male sex, single tooth extraction, extraction of an endodontically compromised tooth, a class I root-sinus relationship, and sinus membrane thickening >10 mm favored pneumatization, but without statistical significance. The maxillary second molar presented the greatest pneumatization (2.25±4.39 mm) compared with other tooth types. This finding was confirmed in the multiple mixed model, which demonstrated a statistically significant impact of the extraction of a second molar compared with the extraction of a first premolar. Conclusions: Maxillary sinus pneumatization was 1.56±3.93 mm on average. The extraction of a second molar led to the greatest extent of pneumatization, which should be considered in the treatment plan for this tooth site.

• 한국산학기술학회논문지
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• 제4권2호
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• pp.114-119
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• 2003

본 연구는 폐수로부터 몇 가지의 유기오염물(Phenol, 2-Chlorophenol, Nitrobenzene)을 비분산 용매추출법으로 동시 제거하는 실험이다. 몇 가지의 용매(MIBK, IPAc, Hexane)에 대하여 분배계수를 구하였고, 용매와 폐수사이의 향류와 병류 흐름에 의한 추출 실험을 하였다. 수용액상의 유량이 증가함에 따라 용매와의 접촉시간이 짧아져 제거율이 떨어지고, 용매의 유량이 증가함에 따라 제거율이 증가함을 알 수 있었다. 그리고 병류보다는 향류에서 유기오염물의 제거율이 증가하는 것을 알 수 있었다. 이러한 결과를 토대로 유기오염물만이 아닌 다른 중금속 오염물 둥도 처리할 수 있는 산업용 폐수처리장치의 개발을 위한 기초자료로 쓰일 수 있다.

• 한국토양환경학회지
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• 제2권2호
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• pp.95-103
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• 1997

유기화합물로 오염된 지반을 정화하는 방법 가운데 화학약액을 주입하는 흙세척 방법은 매우 효과적인 것으로 알려져 있다. 이를 실험실에서 재현하는 경우에는 일반적으로 연성벽체의 주상실험을 실시하게 된다. 이때 유기화합물로 오염된 시편을 화학약액으로 세척하는 과정 중에서 일부의 유기화합물은 연성벽체를 통하여 확산되고, 확산된 양은 화학약액에 의한 세척효율 산정시 반드시 고려하여야 할 것으로 나타났다. 연성벽막을 통한 확산량을 조사하고자 다섯가지의 유기화합물(페놀, 아닐린, 나이트로벤젠, 퀴놀린, 및 2나프톨)을 이용하여 breakthrough 시험을 실시하였다. 나이트로벤젠은 75% 이상이 벽막을 통하여 확산되었다. 나머지의 유기화합물은 25%이하의 확산량을 보였다. 실험중 생분해 효과는 관찰되지 않았다.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2320-2324
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• 2012

A novel approach for metabolite extraction and fingerprinting was introduced based upon the nano-baskets and emulsion liquid membrane-nuclear magnetic resonance (ELM-NMR) technique. The objective of this method is optimizing the fingerprints, minimizing the metabolic variation from analysis, increasing the likelihood differences, and obtaining the maximum extraction yield. Low molecular weight metabolites in rat serum were recovered by ELMs using 12 nano-baskets of calixarene, as both emulsifier and carrier. The yields of ELMs were optimized by the method of one-at-a-time. According to NMR data, the maximum metabolic variation was achieved using scaffold 4 (4 wt %), n-decane membrane, stirring rate of 300 rpm, treat and phase ratios of 0.3 and 0.8, respectively. The results revealed that some calixarenes tend to extract non-specific macromolecules; and repeatability of fingerprints for 7-mediated ELM was maximum and for 3-mediated ELM was minimum. The yield of extractions was obtained to be higher for n-decane and lower for carbon tetrachloride. Among different membranes, the fingerprints by chlorinated liquid membranes were more repeatable than using toluene or n-decane.