• 한국환경과학회지
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• 제1권1호
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• pp.41-46
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• 1992

주거지역에서 대기오염물 시료채취에 대한 장기간 연구를 수행하기 위해서 휘발성 유기 화합물 분석에 적합한 24시간동안의 종합적인 공기시료를 채취하기 위해 공기시료 채취기가 제작되었다. 이 시료 채취기는 시료채취시 요구되는 모든 특성을 포함할 뿐만 아니라, 일반가정에 근접해서 설치되어야하므로 심미적 특성도 포함한다. 이 공기시료 채취기는 흡착제(티넥스)로 채워진 5/8인치 외경의 스테인레스 스틸 트랩 네개를 수용할수 있고, 분당 5-50 밀리리터의 범위에서 네 종류의 공기유속을 이용할수 있게 고안 되었다. 금속필도(10마이크로미터)가 트랩 어댑터의 입구에 직접 부착되었다. 부가적인 특성은 다음과 같다. : 1) 유기물질에 불활성인 재료로 제작 되었고, 2) 날씨에 영향을 받지 않고, 3) 전지를 이용하고, 4) 사람의 호흡영역에서 공기 시료를 채취하고, 그리고 5) 방음제로 싸여진 작은 펌프를 이용하여 조용하게 작동된다. 펌프/전지 장치는 시료채취기의 본체로부터 분리 되었다. 이 장치로 부터 야기되는 소음수준은 주거지역의 허용기준치(뉴저지주 환경보호국 기준)보다 낮았다. 이 공기시료 채취기는 일상 주거지역과 단층의 한 국민학교 옥상에서 성공적으로 작동되었다.

• Bulletin of the Korean Chemical Society
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• 제26권9호
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• pp.1415-1420
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• 2005

The spectral interferences of OH from aqueous solvents in ICP-AES have been studied and eliminated using a cryogenic argon trap. The prominent lines of Bi I 306.772 nm, Al I 309.271 nm, and V II 310.230 nm, which are very seriously overlapped with the OH band, were examined. With an extended torch and high tangential flow of 20 L/min, water vapor from air entrainment was prevented. The combination of a condenser and argon cryogenic trap was able to eliminated most of water vapor carried by the argon sample gas. Removal of OH spectral interference could extend the linearity of the calibration curve 5-10 times on the lower concentration for ICP-AES. Interference Equivalent Concentration (IEC) has been reduced to 5.6, 5.9, and 12.4 times for Bi, Al and V, respectively.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.315-320
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• 2003

Headspace volatile compounds of oxidized fish oil were analyzed by the combination of hexane solvent or solid phase microextraction, gas chromatography and mass selective detector. The optimum condition of headspace analysis by hexane trapping was 23 min absorption time, 96$^{\circ}C$ sample temperature and 20 mL/min air flow rate. The numbers of volatile compounds identified by solvent trapping and SPME were 35 and 14, respectively. Groups having the largest amount and many kinds were hydrocarbons and aldehydes, respectively. The numbers of aldehydes were 15 and 6 for solvent trap and SPME, respectively. These basic data could be used as indicators for the quality changes of fish oil.

• Environmental Analysis Health and Toxicology
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• 제17권2호
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• pp.147-160
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• 2002

Volatile organic compounds (VOCs) are an important public health issue in Korea and many important questions remain to be addressed with respect to assessing exposure to these compounds. Because they are ubiquitous and highly volatile, special techniques must be applied in their analytic determination Valid Personal exposure assessment methods are needed to evaluate exposure frequency, duration and intensity, as well as their relationship to personal exposure characteristics. Biological monitoring is also important since it may contribute significantly in risk assessment by allowing the estimation of effective absorbed doses. This study was on ducted to establish the environmental measurement, personal dosimetry and biological monitoring methods for VOCs. These methods are needed to compare blood, urinary and exhalation breath VOC levels and to provide tools for risk assessment of VOC exposure. Passive monitors (badge type) and a active samplers (trap) for the VOCs collection were used for air sampling. Methods development included determining the minimum detectable amounts of VOCs in each media, as well as evaluating collection methods and developing analytical procedures. Method reliability was assessed by determining breakthrough volumes and comparing results between laboratories and with other methods. A total capacity of trap used in this study was 60ι. Although variable by compound, the average breakthrough was 20％. Also, there was no loss of compounds in trap even if keep for 45 day in -7$0^{\circ}C$. The recovery of active and passive methods was 69％ ~ 126％ and method detection limit was 0.24 $\mu\textrm{g}$/trap and 0.07 $\mu\textrm{g}$/badge. There was no statistical difference (P > 0.05) between active and passive methods.

• Environmental Analysis Health and Toxicology
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• 제17권2호
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• pp.117-123
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• 2002

A gas chromatographic method for the determination of airborne formaldehyde was established. In order to be highly detectable with the electron capture detector, formaldehyde was derivatized to its pentafluorobenzyl oxime form by reacting with O- (2,3,4,5,6- pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) at pH of 4.6 and temperature of 50$^{\circ}C$ for 1 hour. Air samples were collected into a Tedlar$\^$(R)/ bag followed by transferring into water contained in two impingers in series. Collection efficiency in the front trap was higher than 90％. Measurement of selected indoor and outdoor air samples showed higher formaldehyde concentrations in indoor air environments and the importance of ventilation for reducing indoor pollution.

• 한국산림과학회지
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• 제89권1호
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• pp.135-140
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• 2000

솔껍질깍지벌레의 수컷성충이 합성페로몬에 반응하여 비행하는 행동습성을 규명하고자 수직으로 세운 대나무 막대에 지상 0.1m부터 2.0m의 범위에 끈끈이 트랩을 5개 배열하고 그중 0.1m, 1.0m, 2.0m중의 한곳에 합성페로몬을 처리한 bait를 부착하여 각 끈끈이 트랩에서의 수컷부착수를 수관 울폐도별로 조사한 결과는 다음과 같다. 솔껍질깍지벌레 피해 해송림 근처의 공터에서, 페로몬 bait를 지상 2m 및 1m에 설치했을 때 동일 수직 막대상에 있는 각 높이의 트랩당 수컷부착수는 차이가 없었으나 지면근처에 bait를 설치한 경우 지면근처에 수컷이 집중적으로 비행하고 있었다. 수관 울폐도가 소한 임지의 경우, bait를 지상 2m에 설치한 것은 동일 수직막대상에 있는 각 높이의 트랩당 수컷부착수는 차이가 없었으나 지상 1m에 설치한 것은 bait 부위를 중심으로 많은 수컷이 비행하고 있었고, 수관 울폐도가 밀한 장소에서는 bait의 지상높이에 관계없이 수컷은 그 bait의 근처에서 많이 비행하고 있었다. 3개 지역 공히 지면부위에 bait를 설치한 처리구에서 지면부위의 트랩에 가장 많은 수컷이 부착되어 본 해충의 선단지 조사를 위한 페로몬 트랩 설치장소는 지면부위가 가장 적합한 것으로 판단된다. 풍속별 수컷의 페로몬에 대한 반응조사 결과, 페로몬을 감지한 수컷은 풍속이 낮은 공간을 주로 비행하는 것으로 조사되었다.

• Journal of Korean Society for Atmospheric Environment
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• 제9권E호
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• pp.373-381
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• 1993

To understand the human exposure levels of volatile halogenated hydrocar-bons in ambient air, a new rapid and convenient analytical method for determination of the compounds in gaseous phase was evaluated and established. The method is based upon passsive diffusion to personal sampler containing adsorbent and solvent extraction followed by purge trap/ on-column cryof-ocusing method. A new method needs no special instrumentation for gas collection because it is based upon the passive diffusion principle. The typical chromatogram obtained in this study proved that rapid and simultaneous determination of target analytes was possible with good resolution. The developed method was successfully applied to determine the volatile halogenated hydrocarbons in indoor air and the values obtained by this new method were compared with those by direct suction method. The concentration of carbon tetrachloride, 1,1,2-trichloroethylene, chloroform showed the values below 400$\mug/m^3$ except the maximum of 1,513$\mug/m^3$ of chloroform. 1,1,1-Trichloroethane showed approximately 1,000 to 5,000$\mug/m^3$ range of diurnal fluctuation in indoor air.

• 한국전기전자재료학회논문지
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• 제22권11호
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• pp.949-955
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• 2009

In this study, we investigated the effects of Cr dopant (1.0 at% $Cr_2O_3$ sintered at $1000^{\circ}C$ for 1 h in air) on the bulk trap (i.e. defect) and interface state levels of ZnO using dielectric functions ($Z^*$, $M^*$, $Y^*$, $\varepsilon^*$, and $tan{\delta}$), admittance spectroscopy (AS), and impedance-modulus spectroscopy (IS & MS). For the identification of the bulk trap levels, we examine the zero-biased admittance spectroscopy and dielectric functions as a function of frequency and temperature. Impedance and electric modulus spectroscopy is a powerful technique to characterize grain boundaries of electronic ceramic materials as well. As a result, three kinds of bulk defect trap levels were found below the conduction band edge of ZnO in 1.0 at% Cr-doped ZnO (Cr-ZnO) as 0.11 eV, 0.21 eV, and 0.31 eV. The overlapped defect levels ($Zn^{..}_i$ and $V^{\cdot}_0$) in admittance spectra were successfully separated by the combination of dielectric function such as $M^*$, $\varepsilon^*$, and $tan{\delta}$. In Cr-ZnO, the interfacial state level was about 1.17 eV by IS and MS. Also we measured the resistance ($R_{gb}$) and capacitance ($C_{gb}$) of grain boundaries with temperature using impedance-modulus spectroscopy. It have discussed about the stability and homogeneity of grain boundaries using distribution parameter ($\alpha$) simulated with the Z"-logf plots with temperature.

• International Journal of Automotive Technology
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• 제3권3호
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• pp.111-115
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• 2002

Suddenly increasing numbers of automobiles result in making worse air pollution problems. In particular, the emissions from automobiles affect badly on atmosphere. Nowadays, research on catalyst converter and filter trap as a modem technology is very active because PM is designated as a major cancer material and stringent regulations on this are necessary and required. The ceramic filter is very efficient in reducing particular materials up to 80-90% and is evaluated as a very efficient after-treatment technology. However, it comes with decreased engine performance due to increased back-pressure occurred by thermal crack. In order to solve these problems, several methods are proposed such as fuel additive, electric heater and burner types. This experimental study has been conducted with equipped and unequipped a ceramic filter on a displacement 11,000cc diesel engine and compared in terms of engine performance and emission. To measure the emission, D-13 mode is applied and measured quantities of the exhaust gases, particularly in CO, HC, PM, and NOx. Therefore, this research is focused on the basic mechanism and characteristics on harmful materials generated by ceramic filter.

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6047-6052
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• 2013

화장품제조업은 동일한 제품을 대량으로 생산하고 소비되는 구조로 금형을 통한 생산은 필연적이다. 화장품을 담는 용기는 소비자의 구매의사에도 영향을 주는 요소이며 완제품가격에서 차지하는 부분이 크기 때문에 경제성, 심미성과 기능성을 충족시키는 금형이 필요하다. 화장품 용기 중에 사각형태의 용기는 미성형 불량이 다른 형태의 제품보다 자주 발생하는 특징을 가진다. 기존에 사각형 형태의 화장품용기 제작공정은 2단 금형에 사이드게이트 구조로 금형을 제작하는데 이는 후가공과 게이트 흔적이 남는 단점이 있다. 본 연구에서 제안한 오버랩게이트는 후가공이 거의 없고 음각으로 게이트가 절단되는 특징이 있으며, 사이드게이트와 비교하여 Moldflow를 이용한 유동시스템을 시뮬레이션 하였다. 오버랩게이트가 유동성, 고화, 밀도, 에어트랩 등에서 유동성 향상과 불량률을 낮출 수 있는 결과를 확인하였으며, 해석결과를 기반으로 금형을 제작을 하고 사출성형 하였다. 본 연구를 통해 미성형 불량을 줄이고 심미성, 기능성 등의 특성을 가지는 화장품용기 제품의 대량생산 가능성을 검증하였다