• 펄프종이기술
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• 제33권1호
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• pp.64-72
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• 2001

The cigarette ventilation affects not only the amount of tar and nicotine delivery by a cigarette, but also the composition of the smoke. Therefore, it is important to stabilize of variability in cigarette ventilation that would be affected by changes in cigarette components. This work was conducted to determine the major factors that influence the cigarette ventilation and also to provide fundamental informations for improving the uniformity of cigarette performances. To evaluate the effect of cigarette ventilation as a dependant variable, the three independent factors were the air permeability of plugwrap, tipping paper and the filter pressure drop. We determined the effect of paper permeability on ventilation variability and the optimum condition in combinations of independent factors. The mean of cigarette ventilation was increased as plugwrap permeability increases, particularly at 26,000 CU. However, it was exhibited that standard deviation and coefficient of variation of the cigarette ventilation were decreased with increasing plugwrap permeability. At the 600 CU and 1,200 CU of tipping paper permeability, process capability index (Cp) of the cigarette ventilation increased as plugwrap permeability increases. Following the optimum condition of cigarette ventilation induced by fitted regression equation, one was to optimize 50% ventilation level is by combination with plugwrap permeability of 16,000 CU, tipping paper permeability of 810 CU, filter pressure drop of 319 mm$H_2O$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.26-30
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• 1995

We describe the preparation and characterization of epitaxial thin films made with high temperature superconductor, $YBa_2Cu_3O_{7-\delta}$. The influence of processing parameters for YBCO thin films on MgO substrates in-situ grown by the pulsed laser deposition, including parameters of a laser beam energy, oxygen pressure, substrate temperature, target-substrate dis-tance is discussed. The characteristics of YBCO thin films were analyzed by using XRD, R-T measurement, AFM, crosssectional TEM, and RBS. For examples of microwave device applications, The fabrication and characterization of the microstrip lowpass filter and bandpass filter are also presented.

• 대한방사선기술학회지:방사선기술과학
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• 제23권1호
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• pp.91-96
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• 2000

This work was on the reduction of exposure dose and contrast improvement by Use of Heavy Elements Filter From the result of experimental evaluation, it was found that the beam harding of X-ray was not showed in Ho and Gd, heavy elements filters, contrast to Cu and Al filters In which the harding showed. And the ratio of transit dose to surface dose and the load of X-ray tube increase in order of Al, Cu, Gd and Ho, respectively. The contrast of X-ray images using the intensifying screen and the input phosphor showed the higher value in order of Cu, Al, Gd and Ho. Therefore, in the case of using contrast media and phosphor in region of diagnostic radiology, X-ray image quality depends primarily on kVp and heavy elements filters.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 춘계학술대회 논문집
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• pp.549-554
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• 2002

Recently, interest in hygiene has been arouse in the health care field. Consequently, Filters with antibacterial agent applied to improve air quality by sterilizing bacteria, fungi, etc. We actually installed antibacterial air filter containing 2.5wt%Ag zeolite on the air intake route to air-conditioner in passenger cu, and evaluated filter's performance on antibacterial effect. By the microbe liquid spattering method, we found that the antibacterial air filter has notably sufficient antibacterial efficiency against standard strains and wild type strains. Antibacterial effect was observed at whole area of filter media by zone of inhibition test. The evaluation of microbe quantity was conducted through mixing dilution plate culture method. In comparison with ordinary filter, the amount of germs attached on antibacterial air filters was larger. The amount of germs attached on ordinary filters was very small since ordinary filters contained less dust. In comparison in antibacterial air filter with thickness, the amount of germs attached on 9mm filter was smaller than that of on 6mm filter. i.e. thicker filter, superior efficiency.

• 대한방사선기술학회지:방사선기술과학
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• 제17권2호
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• pp.29-35
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• 1994

Tomographic examination requires several times of exposure usually, therefore, reduction of radiation dose per exposure without loss of image quality proves of great benefit to patient. We compared the exposure doses under the following experimental conditions, A and B. A is the combination of SRO 380(rare earth screen) and SRH(high contrast film) with additional Cu filters or without. B is the widely used combination which is BH-III and Cronex-4 without additional filter. As a result, comparing with the condition B, the condition A with additional filter of Cu 0.15 mm + Al 0.7 mm, Cu 0.4 mm+ Al 0.4 mm and Cu 0.8 mm showed better Image quality and lower surface dose, 44 %, 31 % and 24 % of the condition B, respectively.

• 한국자기학회지
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• 제14권6호
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• pp.236-239
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• 2004

미소 자유자성층에 인접한 스핀필터층 (SFL; spin filter layer)을 갖는 Ta3/NiFe2/IrMn7/CoFe1/(NOL1)/CoFe2/Cu 1.8/CoFe( $T_{f}$)/Cu( $t_{SF}$ )/(NOL2)/Ta3.5 (두께단위 nm) 구조의 스페큘라 스핀밸브 (SSV; specular spin valve)를 마그네트론 스퍼터링 장치를 사용하여 제작하였다. 반강자성체 I $r_{22}$M $n_{78}$을 속박층으로 한 스핀필터 스페큘라 스핀밸브 (SFSSV; spin filter specular spin valve) 박막에 대하여 자유자성층의 두께 ( $t_{F}$)와 SFL의 두께 ( $t_{SF}$ )가 각각 1.5nm일 때 극대 자기저항 (MR; magnetoresistance)비 11.9%를 얻었으며, $t_{SF}$ 가 1.0nm으로 감소하여도 11%이상의 MR비를 유지하였다. 이것은 나노산화층 (NOL; nano-oxide layer)에 의한 스페큘라 전자와 SFL에 의한 전류분류효과의 증가 때문이다. 또한, 자유자성층과 피속박층 사이의 층간결합장 ( $H_{int}$; interlayer coupling field)은 RKKY력과 정자기결합력으로 설명할 수 있다. 자유자성층의 보자력 ( $H_{cf}$ ; coercivity of the free layer)은 기존의 스핀밸브 (TSV; traditional spin valve)에 비해 현저히 감소했으며, $t_{F}$가 1nm에서 4nm로 변하여도 4 Oe이하의 값을 유지하였다. 따라서 SFL의 삽입으로 자유자성층의 연자성 특성을 떨어뜨리지 않으면서 자유자성층 두께의 감소와 MR비의 향상을 가능하게 하였다.

• Journal of Magnetics
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• 제10권4호
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• pp.163-170
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• 2005

The RF integrated noise filters are fabricated by photolithography. The stack for the electromagnetic noise filters consists of the nano-granular ($Co_{41}Fe_{38}AI_{13}O_8$) soft magnetic film / $SiO_2$ / Cu transmission line / seed layer (Cu/Ti) / $SiO_2$-substrate. A good signal-attenuation feature along with a low signal-reflection feature is observed in the present filters. Especially in the noise filter incorporated with a $Co_{41}Fe_{38}AI_{13}O_8$ magnetic film with lateral dimensions of $2000{\mu}m$ wide, 15 mm long and $1{\mu}m$ thick, the maximum magnitude of signal attenuation reaches -55 dB, and the magnitude of signal reflection is below -10 dB in the overall frequency range. And this level of signal attenuation is much larger than that of a noise filter incorporated with a Fe magnetic film.

• 대한전자공학회논문지SD
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• 제40권3호
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• pp.1-9
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• 2003

본 연구에서는 1-단자 표면탄성파 공진기를 적용한 사다리형 구조 필터에 대한 전극 두께, 공진기의 반사기 하중 및 정적 정전용량비에 따른 주파수 응답특성의 고찰이 이루어졌으며, 최적화된 매개변수를 이용하여 송신 및 수신단용 RF 필터를 제작하였다. 제작된 필터는 800㎒ 대역 이동통신 시스템에 적용 가능하며, 외부회로에 의한 임피던스 정합이 필요하지 않다. 36°LiTaO₃ 압전기판 위에 Al-Cu(W 3%) 전극을 형성하여 제작하였으며, 3.8㎜×3.8㎜×1.5㎜세라믹 패키지에 실장되었다. 통과대역(25 ㎒)에서의 최소 삽입손실은 2.3 dB, 3-dB 대역폭은 약 33 ㎒, 통과대역 리플은 0.5 dB 미만이며, 약 30 dB 이상의 저지대역 감쇄를 확보할 수 있었다. 또한, 제작된 RF 필터의 내전력성 및 온도 변화에 따른 주파수 응답특성 실험을 통해 약 3.5 W의 내전력성과 -20℃∼80℃에서 최대 0.09 dB/℃의 3-dB 삽입손실 변화를 측정할 수 있었다.

• 분석과학
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• 제16권2호
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• pp.174-178
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• 2003

Analytical chemists frequently use filter papers during the course of experiments without any hesitation. However, the results of analysis could be deteriorated by the various ions which are extracted from filter papers. In some filter paper made for qualitative use, about $300{\mu}g$ sodium and many other cations were detected. Although the quantities of contaminants was low in the filter paper made for quantitative use, significant amount of Fe, Si, Al, Cu and Zn was detected as well as alkali element. Many cations and anions were also detected in the filtrate obtained from the glass fiber filter.

• Progress in Superconductivity
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• 제1권1호
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• pp.42-46
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• 1999

A high-temperature superconducting 1.78 GHz bandpass filter, designed for PCS applications, is presented. The structure consists of microstrip pseudo-lumped elements, which enables miniaturization of the filter. A 5-pole microstrip filter could be realized on a 37 mm $\times$ 9 mm $LaAlO_3$ substrate, using double-sided high-temperature superconducting $YBa_2Cu_3O{7-\delta}$ thin film. This filter showed 0.7 % fractional bandwidth, 0.3 dB insertion loss, and 12 dB return loss in the passband at 60 K.