• 전기학회논문지
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• 제59권2호
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• pp.385-389
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• 2010

This paper presents a microfabricated nanowire diluter which dilutes the concentration of nanowires in solution instead of by the conventional centrifuge process. The device has 16 pairs of gold electrodes in a micro channel composed of a glass substrate and PDMS. We prepared nickel nanowires by the template-directed electrodeposition method using nanoporous anodized aluminum template (AAO). We injected the Dimethylformamide (DMF) solution containing nanowires into the inlet of the diluter while applying square wave voltages on the electrodes to trap the nanowires at the subsequent gold electrodes by means of dielectrophoretic attraction forces. The concentration of nanowires at the outlet of the micro channel was changed as we expected, which illustrates that the device can effectively dilute nanowires and can be applied to a controlled assembly of nanowires.

• 한국입자에어로졸학회지
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• 제15권3호
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• pp.105-113
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• 2019

The exhaust emissions from coal-fired power plants have received much attention because coal-fired power plants are the one of the largest sources of particulate matter (PM) emissions in South Korea. To measure the PM10 and PM2.5, we developed the novel diluter which is comprised of ejector and porous tube in series. The dilution ratio must be defined to calculate particle concentrations of the sampled air as well as to probe match for the isokinetic sampling. For this reason, we verified the dilution ratio of the developed diluter by the flow rate, numerical solution, gas concentration and particle concentration. The ejector-supplied flow rates were 10-50 L/min and the porous tube-supplied flow rates were 30, 50 L/min in this study. All methods above showed similar dilution ratios to each other within 10 % error rate. The dilution ratio was confirmed by comparing mass concentrations before and after the dilution process.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1484-1485
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• 2008

The control of the number and dimension of nanowires is essential for dielectrophoretic(DEP) nanoscale assembly process. However, it is difficult to control the number of nanowires assembled between the electrodes. We have developed a nanowire diluter device, which consists of a glass substrate with gold electrodes and a PDMS layer with microchannel. The diluter device is fabricated by the conventional and soft lithographies using a SU-8 mold. Nickel nanowires (30${\mu}m$-long) are fabricated by a template-directed electrodeposition process using nanoporous alumina templates. A solution containing nanowires is injected into an inlet whereby pulsed voltages are applied to 16 pairs of electrodes in this experiment. The nanowires are trapped or released depending on the pulsed electric field from inlet to outlet (the channel). Therefore, the number of nanowires can be decreased correspondingly if the fixed frequency at each electrode is decreased from electrode to electrode.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2007년도 추계학술대회 논문집
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• pp.382-383
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• 2007

• 한국입자에어로졸학회지
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• 제13권4호
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• pp.165-172
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• 2017

For precise particle measurements in combustion environments, various dilution sampling methods were compared. Dilution equipments using dilution tunnels and hot/cold dilution with porous tube dilutors were most frequently used so far. The combination of porous tube dilutor and ejector diluter has relatively small footprint, and it results in lower particle losses compared to other methods. To determine the portion of condensable particulate matter, proper temperature control and flow control is required.

• 한국대기환경학회지
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• 제18권6호
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• pp.527-538
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• 2002

In this study, the performance of sampling and of analytical methodology was examined against a number of selected volatile organic compounds (VOCs) in the ambient air. The canister-based sampling method for VOCs has been a viable and widely used approach that is based on research and evaluation performed over the past several years. VOCs were determined using canisters by GCMSD analysis. A total of target analyses in this study included approximately 30 VOCs designated in TO-l4A categories including BTEX. The methodology for QC(quality control) was intensively investigated with a wide range of performance criteria such as; (1) cleanliness of canisters, (2) reproducibility of diluter, (3) instrumental detection limits of preconcentrator and GCMSD, and (4) precision and accuracy of GCMSD. For most of the compounds tested, precision was less than $\pm$5%, IDL was 0.2 ppbv, accuracy was $\pm$5%, respectively. This study demonstrated that the combination of canister sampling and GC/MSD analysis could be reliably applied to the measurements of BTEX in ppbv levels that are typically observed in/outdoor air environment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3102-3107
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• 2008

This paper was focused on the particulate matter (PM) on the gasoline and bio ethanol. Bio ethanol as a clean fuel is considered one of the alternative fuels that decreased the PM emission from the vehicle. Particle formation in SI engine was depended on the fuel and engine operating condition. In this paper, Particle number concentration behaviors were analyzed by DMS500 (Differential Mobility Spectrometer) and CPC (Condensation Particle Counter) instrument which was recommended by PMP (Particle Measurement Programme). Particle emissions were measured with various engine operating variables such as air excess ratio ($\lambda$), spark timing and intake valve opening (IVO) at part load condition. In vehicle test, the number of particulate matter was analyzed with golden particle measurement system, which was consist of CVS (Constant Volume Sampler), particle number counter and particle number diluter.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.67-73
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• 2009

Recently, Europe decided to start the regulation of diesel engine nanoparticles because of its well known adverse health effects. The diesel nanoparticles can be classified as solid carbon particles and volatile particles. The volatile particles generates during dilution process by condensation of gas phase volatile compounds such as hydrocarbon. The new nanoparticle regulation considers only solid particles because of difficulty of measurement of volatile particles. The aim of this study is to suggest a proper dilution method that prevent the volatile particle generation. As a result, it is found that the $1^{st}$ dilution air temperature should be above $120^{\circ}C$ in order to prevent volatile particle generation effectively. It is also found that the volatile particles can be removed effectively in the evaporation tube by the increase of evaporation tube temperature. But when exhaust gas is hot enough (>$190^{\circ}C$, in this study) and it is diluted in the first diluter with high temperature air (>$120^{\circ}C$), removal phenomenon of volatile particles by increasing of evaporation tube temperature can not be seen. It means that there are no volatile particles in the diluted exhaust gas. Additionally, dilution ratio is not an important factor for volatile particle generation compared with dilution air temperature or evaporation tube temperature.

• 공업화학
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• 제19권3호
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• pp.264-269
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• 2008

크롬산납안료입자의 합성과정에서 반응조건의 변화에 따른 입자의 성장특성, 첨가제 첨가에 의한 영향, 그리고 마이크로캡슐화에 관하여 조사하였다. 크롬산납 무기안료의 합성과정에서 생성용액의 pH가 낮을수록, 반응물질의 초기농도가 묽을수록 입자크기가 작은 균일한 분산입자를 얻을 수 있었다. 교반속도가 큰 경우에서 평균입자크기의 감소 및 증가에 대한 변화폭이 크게 나타남을 알 수 있었다. 합성된 크롬산납 안료입자의 숙성과정에 황산알루미늄을 첨가하여 표면처리 함으로써 입자크기의 제어가 가능하였고, 입자의 입도분포 상태를 최적 분산 상태로 유지하는 효과가 있음을 알 수 있었다. 안료입자의 마이크로캡슐화가 진행되는 용액의 pH 범위를 9~10, 반응온도를 $90^{\circ}C$ 이상으로 유지하고 마이크로캡슐화 후 충분한 건조를 통해 입자의 수분함량을 0.5% 이하로 유지할 때 최적의 마이크로캡슐화가 됨을 알 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1247-1255
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• 2016

Heparin binding proteins (HBPs) are produced by accessory glands. These are secreted into the seminal fluid, bind to the spermatozoa at the time of ejaculation, favour capacitation, acrosome reaction, and alter the immune system response toward the sperm. The present study was conducted with an objective to assess the effect of purified seminal plasma-HBPs (SP-HBPs) on cross bred cattle bull sperm attributes during two phases of cryopreservation: Pre freezing and freezing-thawing. SP-HBPs were purified from pooled seminal plasma by heparin affinity chromatography. Three doses of SP-HBPs i.e. 10, 20, $40{\mu}g/mLs$ semen were standardized to find out the optimum dose and $20{\mu}g/mLs$ was found to be an optimum dose. Semen as such and treated with SP-HBPs was diluted with sodium citrate-egg yolk diluter and cryopreserved as per the standard protocol. Sperm parameters i.e. motility, viability, Hypo-osmotic swelling test (HOST), acrosome damage, in vitro capacitation and lipid peroxidation were evaluated in SP-HBP treated and untreated (control) semen at both phases of cryopreservation. A considerable variation in percent sperm motility, viability, membrane integrity (HOST), acrosome damage, acrosome reaction and lipid peroxidation was observed at both phases among the bulls irrespective of the treatment. Incubation of neat semen with $20{\mu}g/mL$ SP-HBP before processing for cryopreservation enhanced the average motility, viability, membrane integrity by 7.2%, 1.5%, 7.9%, and 5.6%, 6.6%, 7.4% in pre-frozen and frozen-thawed semen in comparison to control. There was also an average increase of 4.1%/3.9% in in vitro capacitation and acrosome reaction in SP-HBPs-treated frozen-thawed semen as compared to control. However, binding of SP-HBPs to the sperm declined acrosome damage and lipid peroxidation by 1.3%/4.1% and 22.1/$32.7{\mu}M$/$10^9$ spermatozoa in SP-HBP treated pre-frozen/frozen-thawed semen as compared to control, respectively. Significant (p<0.05) effects were observed only in motility, HOST and in vitro acrosome reaction. It can be concluded that treatment of neat semen with SP-HBPs before cryopreservation minimized the cryoinjury by decreasing the generation of reactive oxygen species.