• 한국광학회지
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• 제16권4호
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• pp.297-303
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• 2005

우리는 $^{87}Rb$ 원자의 $5S_{1/2}-5P_{3/2}-4D_{3/2,\;5/2}$ 전이선을 이용하여 레이저의 세기, 편광조합, 그리고 정렬상태에 따른 이중공명광펌핑(double resonance optical pumping; DROP) 스펙트럼을 조사하였다. $5P_{3/2}-4D_{5/2}$ 전이선에서 레이저의 세기에 따른 초미세 구조간의 DROP 신호의 변화가 크게 나타났고, 그 원인은 순환전이선의 낮은 광펌핑 효율 때문이었다. 두 레이저의 편광조합을 달리 했을 때 이중공명의 전이율이 변하고, 이러한 효과가DROP스펙트럼의 변화로 나타났다. 또한 두 레이저가 같은 방향으로 진행하는 경우와 반대 방향으로 진행하는 경우를 비교했을 때, 스펙트럼의 선폭은 각각 12.2 MHz 와 6.9 MHz로 측정되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.111-122
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• 2014

Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

• Journal of Oral Medicine and Pain
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• 제24권1호
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• pp.9-24
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• 1999

Pumping into the upper joint cavity of the TMJ was done on patients who had reducible disc displacement with pain. This article discusses the change in TMJ sounds before and after the Pumping treatment. 20subjects(mean age of $32.1{\pm}10.2yr$)were selected among those who visited the department of Oral Medicine of Yonsei University for the treatment of craniomandibular dysfunctions. Through a thorough history taking, clinical exam and X-ray taking these subjects were diagnosed as reducible disc displacement patients, and they were subdivided into two groups as acute and chronic according to the time the TMJ sound was made. Sonopak was used to measure the TMJ sound before, right after and one-week after the Pumping treatment. VAS was used to measure the degree of subjective TMJ complaints(sounds and pain) before and one-week after the Pumping treatment. Vibration related items included total integral, high integral, low integral, ratio of high integral to low integral, peak amplitude, peak frequency and median frquency. 1. It was not statistically significant between the acute and chronic groups before the treatment. However, total integral, high integral, low integral, peak amplitude, peak frequency, median frequency showed to be greater in the chronic group. 2. In all the subjects, just after the Pumping treatment was done, total integral, high and low integral, peak amplitude and peak frequency significantly decreased (p<0.05). Even after one week, low integral, peak frequency and median frequency significantly decreased (p<0,05), and the TMJ sound diminished accordingly. 3. Comparing the two groups(before and right after the Pumping treatment), there was the following difference ; in the acute group, high integral, high amplitude, high frequency and median frequency significantly decreased(p<0.05). In the chronic group, total integral, high integral, low integral, ratio, peak amplitude and peak frequency significantly decreased(p<0,05). It was not statistically significant between the acute and chronic group. 4. Comparing the two groups(right after and one week after the Pumping treatment), there was the following difference : in the acute group, high integral, high amplitude, high frequency and median frequency significantly decreased(p<0.05), In the chronic group, low integral significantly decreased(p<0.05). However, although it was not statistically significant, after one week, there was an increase in total integral, ratio, peak amplitude and peak frequency compared to right after the treatment group. 5. In the VAS of before and one week after the Pumping treatment of the TMJ pain and sound, the TMJ pain significantly decreased(p<0.05) in both the acute and chronic group. However, it was not statistically significant between the two groups. There was a statistically significant decrease(p<0.05) in the TMJ sound in the acute group after one week of Pumping treatment, but no change was notable in the chronic group and it was not statistically significant between the two groups. From the above results, we can conclude that Pumping into the upper joint cavity of patients having reducible disc displacement is effective in reducing clicking and pain. Therefore, it can be applied in diverse clinical fields.

• 한국유체기계학회 논문집
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• 제6권1호
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• pp.14-22
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• 2003

In this paper the leakage prediction md rotordynamic analysis of an annular seal with a smooth rotor and spiral-grooved stator is performed. For the development of a theoretical model, the three-control-volume analysis of the circumferentially-grooved seal is expanded by considering pressure reduction due to the pumping effect of spiral groove and pressurized flow through the spiral groove. Validation on the present analysis is achieved by comparisons with available experimental data. For the leakage prediction the present analysis generally shows a reasonable agreement with experimental results. Rotordynamic coefficients for rotor speed with spiral angles show same trend, but the magnitudes of rotordynamic coefficients yield differences between analysis and experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.799-804
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• 2002

In this paper the leakage prediction and rotordynamic analysis of an annular seal with a smooth rotor and spiral-grooved stator are performed. For developing a theoretical model, the three-control-volume analysis of the circumferentially-grooved seal is expanded by considering pressure reduction due to the pumping effect of spiral groove and pressure flow through the spiral groove. Results by the present analysis are compared with available experimental data. For leakage the analysis results generally show a reasonable agreement to the experimental results. For rotordynamic coefficients the analysis results show the same trend as the experimental results for rotor speed with spiral angles, but their magnitudes show somewhat large deviations.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.379.1-379
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• 2002

In this paper the leakage prediction and rotordynamic analysis of an annular seal with a smooth rotor and spiral-grooved stator are performed. For developing a theoretical model, the three-control-volume analysis of the circumferentially-grooved seal is expanded by considering pressure reduction due to the pumping effect of spiral groove and pressure flow through the spiral groove. Validation to the present analysis is achieved by comparisons with available experimental data. (omitted)

• 대한기계학회논문집B
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• 제28권12호
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• pp.1501-1510
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• 2004

The pumping characteristics of a single-stage disk-type drag pump (DTDP) are calculated for the variation of the vertical clearance between a rotor and stator by the three-dimensional direct simulation Monte Carlo (DSMC) method. The gas flow mainly belongs to the molecular transition flow region. Spiral channels of a DTDP are cut on the both the upper and lower sides of a rotating disk, but a stationary disk is planar. The interaction between molecules is described by the variable hard-sphere model. The no time counter method is used as a collision sampling technique. The vertical clearance has a significant effect on the pumping performance. Experiments are performed under the outlet pressure range of 0.4∼533 Pa. When the numerical results are compared with the experimental data, the numerical results agree well quantitatively

• Transactions on Electrical and Electronic Materials
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• 제1권2호
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• pp.1-6
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• 2000

This article presents the experiments and considerations possible about gate etching in polysilicon when oxygen gas is added in chamber, We propose the novel study with optical emission spectroscopy in polysilicon etching. It is shown that added oxygen gases play an important role in enhencement of density in chlorine gases as a scavenger of silicon from SiCl$\_$x/. And a small amount of Si-O bonds are deposited and then the deposited thin film protect silicon dioxyde against reaction chlorine with silicon in SiO$_2$. Consequently, we can improve the selectivity of polysilicon the silicon dioxide, which is clearly explained in this model.

• 지질공학
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• 제29권4호
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• pp.439-449
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• 2019

하천 건천화 예방 및 하천수와 지하수의 효율적 연계 이용을 위해서는 지하수 이용이 하천의 수량에 미치는 영향 평가가 수반되어야 한다. 이를 위해서는 대수층과 하천의 다양한 수리특성 조건에 대해 지하수 양수에 따른 하천수량의 변화 분석이 필요하다. 본 연구에서는 하천수위 변동을 반영할 수 있고 지하수 양수에 따른 하천수 감소량을 산정할 수 있는 Baalousha 해석해를 이용하여 하천수위가 지수함수적으로 감소하는 경우와, 감소 후 다시 회복되는 경우에 대해 지하수 양수로 인한 하천수 감소량의 변화 특성을 분석하였다. 대수층의 수리특성으로 투수량계수 10~100 ㎡/d 및 저류계수 0.05~0.3, 하천의 수리특성으로 하상수리전도성 0.01~20 m/d, 하천수위 감수상수 0.1~1.0 1/d, 그리고 하천과 관정의 이격거리 100~500 m 조건에 대해 지하수 양수량 대비 하천수 감소량인 하천수 기여도를 산정하고 그 거동 특성을 하천수위 변동 유무에 따라 종합적으로 분석, 제시하였다. 하천수위 감소 영향을 고려하였을 경우 하천수 기여도가 크게 감소하고 하천-관정 이격거리와 수리확산도의 함수인 하천고갈인자 값에 영향을 작게 받는 것으로 나타났으며, 반면에 하천수위 감소 후 회복되는 조건에서의 하천수 기여도는 하천수위 변동이 없는 경우와 큰 차이가 없는 것으로 나타났다. 이러한 결과는 하천수위 조절을 통해 지하수 양수시 하천수 및 대수층 저류량에 미치는 상대적 영향의 통제가 가능함을 의미한다.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2003년도 somma/kms meeting
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• pp.79-79
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• 2003