• 한국식품영양학회지
• /
• 제12권2호
• /
• pp.191-191
• /
• 1999

A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{\circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{\circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$\mu$g/ml and the purge efficiency of each compound was over 70%.

• Bulletin of the Korean Chemical Society
• /
• 제22권2호
• /
• pp.171-178
• /
• 2001

A Purge and Trap Concentrator has been used to analyze various volatile organic compounds in water, operating several parameters affecting the extraction efficiencies of these compounds. The object of the present study was to observe the purge efficiencies of 40 volatile organic compounds (VOCs) in water, according to the change of parameters (purge time, dry purge time, sample temperature), and to determine the optimum condition of analysis of VOCs. The Purge and Trap Concentrator was interfaced with a narrow capillary connected to a gas chromatography mass spectrometer. At this condition, the detection limits of VOCs were in the range of 0.1-0.5 ㎍/L.

• 한국자동차공학회논문집
• /
• 제9권6호
• /
• pp.85-93
• /
• 2001

Minimized canister flow restriction and maximized flow uniformity are desired to maximize a purge capability. With the impending ORVR(On Board Refueling Vapor Recovery) systems, the reduction of restriction and increase of flow uniformity in a carbon canister becomes even more critical to meet the stringent regulation. In this study, three-dimensional numerical simulations have been performed to investigate the three-dimensional internal flow patterns in a carbon canister during purge. The effects of the declined angle of the purge pipe and the number of partitions on the pressure drop and purge efficiency in a carbon packed bed are examined. Results show that the purge efficiency and space velocity distribution are affected in the upstream region of 40% of total canister bed by porosity of carbon granule and angle of purge pipe. It is also found that the purge efficiency decreases with increasing the number of partitions.

• 대한한의학원전학회지
• /
• 제32권4호
• /
• pp.35-46
• /
• 2019

Objectives : While Comparative Pulse Diagnosis of Renying pulse(人迎脈) and Cunkou pulse(寸口脈) is one of the three major pulse diagnostic methods in "Huangdineijing" along with Three Positions and Nine Indicators Pulse Diagnosis(三部九候脈診法) and Cunkou Pulse Diagnosis(寸口脈診法), it has died out in later periods. This study aims to examine this lost method. Methods : Annotations of "Huangdineijing" were examined along with descriptions of the author's own experience. Results & Conclusions : Renying is the Renying(人迎) point from the Stomach Channel(ST), while Cunkou is the Taiyuan(太淵) point from the Lung Channel(LU). These two points are compared in order to determine the deficiency and excess of the Zangfu(臟腑). Normal pulses(平脈) are Soft(軟脈) or Moderate(緩脈), while Stirred pulses(躁脈) are Stringy(弦脈), Tight(緊脈), Slippery(滑脈) or Long(長脈). If the Renying is once active where Shaoyang pulse is active, purge the Gallbladder and supplement the Liver. If there is Stirred pulse, purge the Triple Burner and supplement the Pericardium. If the Renying is twice active where Taiyang pulse is active, purge the Bladder and supplement the Kidney. If there is Stirred pulse, purge the Small Intestine and supplement the Heart. If the Renying is three times active, where Yangming pulse is active, purge the Stomach and supplement the Spleen. If there is Stirred pulse, purge the Large Intestine and supplement the Lung. If the Cunkou is once active where the Jueyin pulse is active, purge the Liver and supplement the Gallbladder. If there is Stirred pulse, purge the Pericardium and supplement the Triple Energizer. If the Cunkou is twice active where the Shaoyin pulse is active, purge the Kidney and supplement the Bladder. If there is stirred pulse, purge the Heart and supplement the Small Intestine. If the Cunkou is three times active where the Taiyin pulse is active, purge the Stomach and supplement the Spleen. If there is Stirred pulse, purge the Lung and supplement the Large Intestine.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
• /
• pp.336-340
• /
• 2009

This paper presents experimental results carried out on the purge characteristic of the anodic dead-end mode fuelcell and how to improve the cell performance by pulsation effects. The dead-end mode fuelcell has some merits that a fuel supplying device is not needed and the cell power is higher than that in the open mode fuelcell. However, the purge is necessary for preventing the porous media from being flooded by liquid water formed in the channel. At this time, the un-reacted fuel is discharged with the liquid water together in purge process. The discharged fuel can make the fuel efficiency lower. Therefore, the number of purge times should be decreased for the better fuel efficiency. In this study, the outlet of the anode channel was equipped with a purge solenoid valve and a pulsation generator. The purge times was decreased when the current density decreased and operation pressure increased without the pulsation effects. In addition, when the pulsation effects such as various frequencies or amplitudes were applied, purge times was alleviated up to 40%.

• Korean Chemical Engineering Research
• /
• 제57권4호
• /
• pp.531-538
• /
• 2019

고분자전해질 연료전지(PEMFC)의 성능이 개선됨에 따라 생성물인 물과 열의 발생이 증가하고 이를 처리하기 위한 관리기법이 중요해지고 있다. 본 연구에서는 물 관리 기법으로 수소 재순환을 적용하였고, 수소 재순환 유량(flow rate)과 퍼지 간격(purge interval) 및 지속 시간(duration)이 연료전지의 성능에 미치는 영향에 대한 실험을 수행하였다. Purge 조건의 영향을 해석하기 위하여 수소극의 압력, 연료의 습도, 운전 간의 연료 이용 효율과 물 배출 양을 측정하였다. 수소 재순환 유량이 증가할수록 수소극 출구의 압력 저하로 인하여 스택 성능이 낮아졌다. Purge 조건에 따라서 물을 효과적으로 배출하지 못해 순간적인 전압 강하가 발생하거나 혹은 잦은 purge로 인해 수소극의 습도를 유지하지 못하여 성능이 점차적으로 감소하는 것을 확인하였다. Purge 조건 실험을 통하여 수소극의 습도를 유지하고 응축된 물을 충분히 배출할 수 있는 purge interval과 duration을 선정하였고, 이를 통하여 스택의 성능과 연료 이용 효율을 향상시킬 수 있었다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.175-179
• /
• 2000

A combustion project was completed regarding the development of a high-flow-rate purge burner in cooperation with three city gas companies(Pusan, Taegu, Samchulli). The project, started in May 1991, aimed at purging the line-packed-gas safely and quickly before getting into gas pipe working or relocation. According to the results, the purging noise is less than 80dB due to silencer screen. multi-nozzle and outlet inserted tube employed. In addition, the developed burner shows an increased work efficiency of 40-50% more as compared to the performance of conventional purge equipments. The project result is regarded as the first high-flow-rate purge burner developed within Korea. contributing to shortening purge hours, safe field work and easiness of purge site selection.

• 한국응용과학기술학회지
• /
• 제19권2호
• /
• pp.108-116
• /
• 2002

Experimental Study was carried out for benzene desorption by purge gas or evacuation in an activated carbon bed. As purge gas flow rate increased, desorption rate increased due to the higher interstitial linear gas velocity. For various purge gas flow rates, desoption curves almost got together if they were plotted against dimensionless time. At a higher flow rate, mass transfer zone became narrower. Temperature drop in the bed was more fast and severe at higher flow rates and higher outer temperature. It was found out that desorption was almost completed when the temperature in the drop of the bed returned to the initial temperature before temperature drop. Desorption by vacuum purge was completed in shorter time than desorption by purge gas. Countercurrent purge was more effective than cocurrent purge.

• 대한화학회지
• /
• 제39권8호
• /
• pp.635-642
• /
• 1995

Purge & Trap-GC/MS 전처리 방법과 capillary column gas chromatography/ mass spectrometry 분석법을 이용한 휘발성유기물 분석에 있어서, 보다 효울적으로 시료를 주입하는 방법에 대하여 연구하였다. 미국환경청에서 제시한 물 중의 휘발성 유기물 분석방법에서 이용하는 moisture control nodule 과 cryorefocusing에 따르는 여러가지 문제점을 관찰하였다. 이러한 무제점을 해결하기 위해 개선된 시료 주입방식을 제시하고, 여러가지 트랩과 컬럼의 특성을 조사하여 최적 실험조건을 구하였다. 이때 사용한 Purge & Trap 장치의 트랩은 carbopack B/carboxen 1000과 1001이었으며, 기체 크로마토그라프의 컬럼은 주문 제작한 dimethyldiphenylpolysiloxane crosslingking moiety capillary 컬럼을 사용하였다. 본 연구에서 제시한 방법으로 물 중에 포함된 54종의 휘발성유기물을 대상으로 동시분석할 때의 정확도와 정밀도에 대해 조사하였으며, 각 화합물에 대한 method detection limit를 구하였다.

• 분석과학
• /
• 제14권5호
• /
• pp.392-399
• /
• 2001

생물시료에 존재하는 휘발성 유기화합물 중 n-butylbenzene과 1,2-dibromo-3-chloropropane (DBCP)를 기체크로마토그래피/질량분석기-선택이온검색법에 의해 수행하였다. 시료 중 휘발성 유기화합물은 $100{\mu}m$ polydimethyl siloxane (PDMS) fiber를 사용하여 headspace solid phase microextractio (SPME) 및 purge & trap 방법에 의해 추출 및 비교하였다. SPME에 의한 회수율은 n-butylbenzene의 경우 85.8%, DBCP의 경우 92.4%로 나타났고 검출한계는 각각 $0.15{\mu}g/kg$, $0.05{\mu}g/kg$로 나타났다. 반면, purge & trap의 경우 회수율은 n-butylbenzene의 경우 115.2%, DBCP의 경우는 80.9%로 나타났고 검출한계는 각각 $0.04{\mu}g/kg$ 및 $0.70{\mu}g/kg$로 나타나 두 방법에 있어 국내에서 규제하는 검출한계측면에서 큰 차이는 없었다.