• International Journal of Precision Engineering and Manufacturing
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• 제6권3호
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• pp.51-55
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• 2005

This study addresses the contamination sensitivity test of a typical fuel pump for an automotive vehicle. The objective of the study is to find the contamination sensitivity coefficient of a fuel pump on specific contaminant particle sizes so that an optimal fuel filter could be selected. To achieve the objective, the degradation of discharge flow rate of the fuel pump is measured under the experiments of various contaminants size ranges of ISO test dust up to $80\;{\mu}m$. The fundamental theory of contamination sensitivity is introduced and the contamination sensitivity coefficients are estimated using the experimental data. Maximum contamination sensitivity coefficient of $5\chi\;10^{-6}\;L/min{\cdot}Ea$ is found in the contaminant size range of $40\;{\mu}m\~50\;{\mu}m$. The magnified picture of the surface of vane disc reveals that the abrasive wear is the principal cause of discharge flow rate degradation. Hence, this study reveals that a high efficiency filter for contaminant particles especially in the size range of $30\;{\mu}m\~70\;{\mu}m$ especially should be used to maintain the service life of the fuel filter.

• 한국정밀공학회지
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• 제21권6호
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• pp.102-108
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• 2004

This study addresses the contamination sensitivity test of a typical fuel pump for automotive vehicle. The objective of the study is to find the contamination sensitivity coefficient of fuel pump on specific contaminant particle sizes so that optimal fuel filter could be selected. To achieve the objective, the degradation of discharge flow rate of fuel pump was measured under the experiments of various contaminants size ranges of ISO test dust up to 80${\mu}{\textrm}{m}$. The fundamental theory of contamination sensitivity was introduced and the contamination sensitivity coefficients were estimated using the experimental data. Maximum contamination sensitivity coefficient of $5{\times}10^{-6}$ L/minㆍEa was found on the contaminant size range of 40${\mu}{\textrm}{m}$∼50${\mu}{\textrm}{m}$. The magnified picture of the surface of vane disc revealed that the abrasive wear was the principal cause of discharge flow rate degradation. Hence, this study revealed that high efficiency filter on the contaminant particle size range of 30${\mu}{\textrm}{m}$∼70${\mu}{\textrm}{m}$ especially should be used to maintain the service lift of the fuel filter.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.124-130
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• 1998

A mathematical model describing gear pump flow degradation in the presense of abrasive particles is presented. The model considers the operating parameters as Sommerfeld number, so that contamination sensitivity test results could be conversed to field application to predict contamination service life. A method to estimate the volumetric efficiency and the contamination level of a pump is proposed by measuring the temperature differences in the fluid. Test results show the validity of the theoretical establishments.

• Journal of Radiation Protection and Research
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• 제25권1호
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• pp.11-19
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• 2000

동적섭식경로모델 DYNACON에 대한 입력변수의 민감도 분석을 장반감기 핵종 $(^{137}Cs,\;^{90}Sr)$에 대해 침적시점의 함수로 평가하였다. 또한 장, 단기간 음식물 (곡류, 엽채류, 우유) 오염에 대한 입력변수의 영향이 고찰되었다. 입력변수는 LHS 기법으로 표본 추출되었으며, 민감도 지수는 PRCC로 나타냈다. 핵종과 음식물의 종류에 따른 민감도 지수는 침적시점 뿐 아니라 장, 단기간 오염에 있어서도 뚜렷이 다르게 나타났다. 작물의 성장기 침적의 경우 장, 단기간 오염 모두 잎흡수에 의한 오염 관련변수가 중요하였다. 또한 작물의 비성장기 침적의 경우 단기간 오염에 있어서도 잎흡수에 의한 오염 관련변수가 중요하였다. 장기간 오염의 경우 잎흡수에 의한 오염 관련변수의 영향은 줄고 뿌리흡수에 의한 오염 관련변수의 영향이 증가하였다. 특히 이러한 현상은 작물의 성장기 침적에 비해 비성장기 침적의 경우에, $^{l37}Cs$ 침적에 비해 $^{90}Sr$ 침적의 경우에 보다 뚜렷하였다. 목초의 성장기 침적의 경우 우유로의 핵종 전달계수, 젖소의 일일 목초 섭취량과 같은 가축 특성 관련변수가 상대적으로 우유의 오염에 중요한 입력변수로 나타났다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.665-668
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• 2006

Sodium is a serious contamination in LTPS TFT process. It causes the abnormal characteristics of TFT in operation. Contaminated areas can be seen in SEM images, but EDX measurements do not have adequate sensitivity to confirm the presence of superficial sodium residues. We employed SIMS as a fast analysis method to map the non-uniform distribution of sodium on the surface. SIMS can also indicate the thickness of the contamination.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.330-337
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• 2006

Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for delineation of subsurface contamination in situ, and then be supplemented with a minimum confirmatory sampling and laboratory testing program. While the resistivity measurement have potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements for delineating the subsurface contamination. This study is focused on verifying the applicability of resistivity and capacitance measurements on CPT module to provide information on contaminated subsurface by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination.

• 한국동물위생학회지
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• 제37권4호
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• pp.253-261
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• 2014

Porcine circovirus disease (PCVD) is a major problem of swine industry worldwide, and diagnosis of PCV2, causal agent of PCVD, has been doing in clinical laboratories of pig disease by polymerase chain reaction (PCR) methods. But the PCR analyses have a serious problem of misdiagnosis by contamination of DNA, in particular, from carryover contamination with previously amplified DNA or extracted DNA from field samples. In this study, an uracil DNA glycosylase (UNG)-based direct PCR (udPCR) without DNA extraction process and DNA carryover contamination was developed and evaluated on PCV2 culture and field pig samples. The sensitivity of the udPCR combined with dPCR and uPCR was same or better than that of the commercial PCR (cPCR) kit (Median diagnostics, Korea) on PCV2-positive serum, lymph node and lung samples of the pigs. In addition, the udPCR method confirmed to have a preventing ability of mis-amplification by contamination of pre-amplified PCV2 DNA from previous udPCR. In clinical application, 170 pig samples (86 tissues and 84 serum) were analysed by cPCR kit and resulted in 37% (63/170) of positive reaction, while the udPCR was able to detect the PCV2 DNA in 45.3% (77/170) with higher sensitivity than cPCR. In conclusion, the udPCR developed in the study is a time, labor and cost saving method for the detection of PCV2 and providing a preventing effect for DNA carryover contamination that can occurred in PCR process. Therefore, the udPCR assay could be an useful alternative method for the diagnosis of PCV2 in the swine disease diagnostic laboratories.

• 한국자기학회지
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• 제10권6호
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• pp.310-317
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• 2000

먼지 입자에 의한 thermal asperity(TA)써 발생은 드라이브의 신뢰성에 큰 영향을 미친다. 본 논문에서는 드라이브의 입자 분사 시험 등을 통하여 헤드 및 디스크의 TA민감도를 분석하고 TA발생의 중요 인자들을 고찰하였다. 헤드의 TA 민감도는 MR 및 GMR 센서의 재질 및 특성에 많은 영향을 받으며 특히 바이어스 전류가 증가함에 띠라 TA 민감도는 증가한다. 한편 슬라이더의 ABS 형태를 적절히 설계 함으로서 TA를 어느 정도 감소시킬 수 있다. 디스크의 경우 디스크 카본 overcoat층의 scratch저항력을 증가시킴으로써 TA의 발생을 감소시킬 수 있다. 그러나 먼지 입자가 디스크 표면에 부착되는 정도를 결정하는 표면에너지는 TA 발생에 거의 영향을 미치지 않는다. 이는 TA 발생을 초래하는 먼지 입자의 크기가 1-2 $\mu\textrm{m}$로서 디스크 표면의 윤활막에 의한 모세관력이 너무 커서 입자들이 디스크표면으로부터 이탈할 수 없기 때문이다

• 한국식품위생안전성학회지
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• 제12권4호
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• pp.294-299
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• 1997

A study was conducted to determine contamination status of fish sold at wholesale market in Seoul. A total of 79 samples (35 different kindry fish) were collected from the wholesale market. E. coli and coliform group bacteria were cultured and tested for sensitivity against antibiotics. The results are summarized as follows; 1. E. coli was isolated from 23 out of 79 samples (29.1%), and coliform groups from 53 out of 79 (67.1%). 2. Of coliform group, Citrobacter freundii was the most common and Enterobacter clacae was the next. 3.23 E. coli strains isolated from fishes were resistant to Oxacillin, Erythromycin and Lincomycin, meanwhile 23 E. coli strains were sensitive to Cefoperazone, Ceftazidime, Imipenem, and Ciprofloxacin.

• Current Photovoltaic Research
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• 제6권1호
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• pp.17-20
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• 2018

The dependency of the photovoltaic performance of p-/n-type silicon solar-cells on the metallic contaminant type (Fe, Cu, and Ni) and concentration was investigated. The minority-carrier recombination lifetime was degraded with increasing metallic contaminant concentration, however, the degradation sensitivity of recombination lifetime was lower at n-type than p-type silicon wafer, which means n-type silicon wafer have an immunity to the effect of metallic contamination. This is because heavy metal ions with positive charge have a much larger capture cross section of electron than hole, so that reaction with electrons occurs much more easily. The power conversion efficiency of n-type solar-cells was degraded by 9.73% when metallic impurities were introduced in the silicon bulk, which is lower degradation compared to p-type solar-cells (15.61% of efficiency degradation). Therefore, n-type silicon solar-cells have a potential to achieve high efficiency of the solar-cell in the future with a merit of immunity against metal contamination.