• Applied Microscopy
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• 제44권2호
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• pp.61-67
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• 2014

Layered structures of fiber cell wall of Korean red pine (Pinus densiflora) were investigated by confocal reflection microscopy (CRM). CRM micrographs revealed detailed structures of the fiber cell wall such as S1, S2, and S3 layers as well as transition layers (S12 and S23 layers), which are present between the S1, S2, and S3 layers. Microfibril angle (MFA) measurement was possible for the S2 and S3 layer in the cell wall. The experimental results suggest that CRM is a versatile microscopic method for investigation of layered structures and MFA measurement in individual sub layer of the tracheid cell wall.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권2호
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• pp.117-123
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• 2009

$Pb_{x}Cd_{1-x}S$ films are prepared in the composition range of 0.05${\leq}x{\leq}$0.25, using a chemical bath deposition growth technique under optimum conditions amide at realizing good photo response. The x-ray diffraction results show that the films are of PbS-CdS composite with individual CdS and PbS planes. The films exhibit two direct band gaps, 2.4 eV attributed to CdS, while the other varies continuously from 2.4 eV to 1.3 eV. The films surface morphology is smooth with crystallite, whose grain size increases with increasing mole fraction (x). The decrease in band gap with increase in lead concentration suggests inter-metallic compound of PbS (Eg=0.41 eV) with CdS (Eg=2.4 eV)

• 한국안광학회지
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• 제5권1호
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• pp.43-48
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• 2000

Polarizer와 Analyzer의 Rotation 각에 의해 광의 luminance를 조절할 수 있다. Contrast Sensitivity에 대응한 luminance 값 $L_{max}$, $L_{min}$은 평균 luminance($L_m$)의 회전각 ${\theta}_m$ 최대 진폭과 최소 진폭에 대응하는 회전각 (${\theta}_{max}$, ${\theta}_{min}$)로 부터 구할 수 있다. $$L_{max}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1+C_s^{-1})$$ $$L_{min}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1-C_s^{-1})$$ 평균 luminance($L_m$)의 회전각 ${\theta}_m$과 측정할 Contrast Sensitivity($C_s$)로부터 polarizer와 analyzer의 회전각(${\theta}_{max}$, ${\theta}_{min}$)을 얻었다. $${\theta}_{max}=cos^{-1}[cos{\theta}_m{\cdot}(1+C_s^{-1})^{1/2}]$$ $${\theta}_{min}=cos^{-1}[cos{\theta}_m{\cdot}(1-C_s^{-1})^{1/2}]$$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.56-59
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• 2004

The stochiometric composition of $AgGaS_2$ polycrystal source materials for the $AgGaS_2/GaAs$ epilayer was prepared from horizontal furnace. From the extrapolation method of X-ray diffraction patterns it was found that the polycrystal $AgGaS_2$ has tetragonal structure of which lattice constant $a_0$ and $c_0$ were 5.756 ${\AA}$ and 10.305 ${\AA}$, respectively. $AgGaS_2/GaAs$ epilayer was deposited on throughly etched GaAs (100) substrate from mixed crystal $AgGaS_2$ by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $590^{\circ}C$ and $440^{\circ}C$ respectively. The crystallinity of the grown $AgGaS_2/GaAs$ epilayer was investigated by the DCRC (double crystal X-ray diffraction rocking curve). The optical energy gaps were found to be 2.61 eV for $AgGaS_2/GaAs$ epilayer at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation, then the constants in the Varshni equation are given by ${\alpha}=8.695{\times}10^{-4}eV/K$, and $\beta$=332 K. From the photocurrent spectra by illumination of polarized light of the $AgGaS_2/GaAs$ epilayer, we have found that crystal field splitting $\Delta$ Cr was 0.28 eV at 20 K. From the PL spectra at 20 K, the peaks corresponding to free and bound excitons and a broad emission band due to D-A pairs are identified. The binding energy of the free excitons are determined to be 0.2676 eV and 0.2430 eV and the dissociation energy of the bound excitons to be 0.4695 eV.

• Journal of Plant Biotechnology
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• 제30권1호
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• pp.7-11
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• 2003

2배체 담배인 Nicotiana plumbaginifolia를 대상으로 상염색법과 FISH 기법을 통한 염색체 분석을 수행하여 다음과 같은 결과를 얻었다. N. plumbaginifolia의 체세포 염색체 수는 2n=20이며, arm ratio 비교를 통한 핵형 분석에서 중기 염색체 조성은 3쌍의 중부 염색체 (염색체 1,2 및 7)와 7쌍의 차중부 염색체 (염색체 3, 4, 5, 6, 7, 9 및 10)로 관찰되었다. 염색체의 길이는 2.29~4.50 $\mu\textrm{m}$로 나타났으며, 염색체 1번과 2번은 부수체 염색체로 관찰되었다. 5S와 45S rDNA를 탐침으로 FISH를 수행한 결과 2번 염색체의 동원체 부위에서 한 쌍의 5S signal이 확인되었고, 1번 염색체의 부수체에서 한 쌍의 45S signal이 관찰되었다.

• 센서학회지
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• 제16권6호
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• pp.419-427
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• 2007

Single crystal $ZnIn_{2}S_{4}$ layers were grown on a thoroughly etched semi-insulating GaAs(100) substrate at $450^{\circ}C$ with the hot wall epitaxy (HWE) system by evaporating the polycrystal source of $ZnIn_{2}S_{4}$ at $610^{\circ}C$ prepared from horizontal electric furnace. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $ZnIn_{2}S_{4}$ thin films measured with Hall effect by van der Pauw method are $8.51{\times}10^{17}\;electron/cm^{-3}$, $291{\;}cm^{2}/v-s$ at 293 K, respectively. The photocurrent and the absorption spectra of $ZnIn_{2}S_{4}$/SI(Semi-Insulated) GaAs(100) are measured ranging from 293 K to 10 K. The temperature dependence of the energy band gap of the $ZnIn_{2}S_{4}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)$=2.9514 eV. ($7.24{\times}10^{-4}\;eV/K$)$T^{2}$/(T+489 K). Using the photocurrent spectra and the Hopfield quasicubic model, the crystal field energy(${\Delta}cr$) and the spin-orbit splitting energy(${\Delta}so$) for the valence band of the $ZnIn_{2}S_{4}$ have been estimated to be 167.8 meV and 14.8 meV at 10 K, respectively. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}$-, $B_{1}$-, and $C_{41}$-exciton peaks.

• 대한간호학회지
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• 제4권2호
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• pp.144-158
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• 1974

This study was undertaken in an attempt to; 1) measure value orientation of nursing activities, 2) identify the relationship between nurse's role perception and patient's expectation, and 3) evaluate the pattern of nursing education and nursing service administration. 203 hospitalized adults and 203 professional nurses from 11 general hospitals in Seoul during the period of July to December 1973 were tested according to questionnaire based on 4 categories of clinical nursing activities, 1) physical care, 2) observation and control, 3) psycho-social care and 4) therapeutic measures. Results of the study are as follows: 1. Nurses were more concerned than patients in the physical care category. Significant difference was revealed by p<.01 level (t=2.800). Mean value score of nurses was average (2.84), and mean value score of patients was relative' y low (2.49). None of the physical care category questionnaire items were over 3.5. 2. Respondents from hospitals of total care system revealed significant difference in the physical care category by P〈.025 level. (t=2.242). Mean value score of both group were average level (nurse 2.90, patient 2.53), nurses showed higher concern. 3. Difference between nurse's role perception and patient's expectation in observation and control category was revealed non- significance by p〉0.05. level (t=1.238). Mean value score of both group revealed relatively high (nurse=3.44, patient 3.19). 4. Difference between nurse's role perception and patient〉expectation in psycho-social cart category revealed non- significance by p〉.05 level (t=0.758), Mean value score of both group revealed average level (nurse =2.71, patient =2.53), 5. Non- significant difference was noted between B. S. N. and diploma nurse's role perception in the psycho- social care category by p> 0.1 level (t=0.316). 4. Difference between nurse's role perception and patient's expectation in the rapeutic me assures category revealed non- significance by p〉0.05 level) t=0.503). Horses showed high concern by mean value score 3.56 level and patients relatively high by 3.41. All items of this category revealed very high or relatively high value score.

• 분석과학
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• 제14권3호
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• pp.259-265
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• 2001

ZnO, CdS, rutile-$TiO_2$ 및 혼합 rutile-$TiO_2$/ZnO와 같은 여러 반도체를 이용하여 Congo Red를 광 촉매 분해시켰다. 연구 결과 ZnO, CdS, rutile-$TiO_2$ 중에서는 CdS의 광 촉매 효과가 제일 컸는데 이것은 CdS가 제일 작은 band gap 에너지를 가지고 있기 때문이었다. 또한 혼합 촉매에서는 ZnO의 함량이 rutile-$TiO_2$에 비하여 상대적으로 높을수록 분해 반응을 촉진하였다. 이것은 $Zn^{2+}$ 가수분해 생성물이 구조적으로 안정한 화합물인 rutile-$TiO_2$의 표면을 덮음으로서 자외선 흡수를 차단하기 때문에 라디칼 생성을 저해하기 때문이었다.

• 시멘트
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• 통권92호
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• pp.41-54
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• 1983

Calcium Silicate의 생성 및 분해에 미치는 $K_2SO_4$와 $MgSO_4$의 영향을 비교 검토하였으며 Calcium Silicate의 생성을 최대로 하는 $SO_3$, MgO와 $K_2O$의 최적비를 반응표면분석기법으로 조사하였다. $K_2SO_4$의 혼합비 증감에 따라 $C_3S$의 생성촉진에 미치는 영향은 없었다. $C_3S$의 조합원료에 $CaSO_4$를 4.0wt$\%$이상 첨가시 $CaSO_4$는 $C_2S$주위에 Sulphate reaction rim을 형성함으로써 $C_2S$와 CaO의 반응을 방해해 $C_3S$의 생성을 억제하였으나 적당량의 MgO가 첨가되면 $CaSO_4$가 4.0wt$/%$이상이라도 $C_3S$의 생성은 억제되지 않았다. $C_3S$의 생성을 최대로 하기 위한 $SO_3$, MgO와 $K_2O$의 최적비를 반응표면분석기법을 이용하여 다음과 같은 결론을 얻었다. 1. $K_2SO_4$는 $K_2O$에 비해 소결에 미치는 영향이 적으므로 크링카에 고용되고 남은 $K_2O$는 전량 $K_2SO_4$로 전환시켜야한다. 2. $SO_3$와 $K_2O$의 최적비율은 1.5이다. 3. $CaSO_4$와 MgO의 최적비율을 유지하기 위해서는 $CaSO_4$중의 wt$\%SO_3$=0.7의 수준으로 Sulphate의 함량을 조절하여야 한다. 4. $SO_3$와 결합하고 남은 $K_2O$가 0wt$\%$인 경우는 $K_2SO_4$=2.3wt$\%$, MgO=1.5wt$\%$일때 $C_3S$의 생성이 최대로 된다. 5. $SO_3$와 결합하고 남은 $K_2O$가 2.0wt$\%$인 경우는 $K_2$$SO_4$=4.5wt$\%$, MgO=3.0wt$\%$일때 $C_3S$의 생성이 최대로 된다.

• 대한수학회논문집
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• 제15권4호
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• pp.675-681
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• 2000

Let f : M longrightarrow M be a homotopically periodic self-map of a closed surface M. Except for M = $S^2$, the Nielsen number N(f) and the Lefschetz number L(f) of the self-map f are the same. This is a generalization of Kwasik and Lee's result to 2-dimensional case. On the 2-sphere $S^2$, N(f) = 1 and L(f) = deg(f) + 1 for any self-map f : $S^2$longrightarrow$S^2$.