• 임상간호연구
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• 제17권2호
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• pp.138-149
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• 2011

Purpose: The objective of this research was to explore levels of patient safety and safe nursing activities depending on the level of nurse staffing, in order to provide effective management of nurse personnel. Methods: The research was conducted with 455 nurses from eight hospitals in B city. Data were collected according to the level of nurse personnel from second (nurse vs. patient ratio of 2.0-2.5) to fifth (ratio of 3.5-4.0) rank. The survey tools were, 'Questionnaire on Patient Safety, a Hospital Survey on Patient Safety Culture developed by AHRQ (2007), and 'Questionnaire on Patient Safety Nursing Act, in which the questions were selected from nursing-related items (Medication 6 & Safety Nursing Assurance Act 4) in the Safety Evaluation developed by Evaluation Institute of Medical Institution. Data were analyzed with SPSS PC 12.0 program using descriptive statistics, $x^2$ test, ANCOVA and $Scheff{\grave{e}}$. Results: The nurses' overall cognition level on patient safety and safe nursing activities showed that nurses who are in the second and third rank had higher scores than those in lower ranks. Conclusion: The results of this study indicate that hospitals need a higher ratio level for nurse personnel in order to assure patient safety and safe nursing activities.

• Advances in nano research
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• 제5권3호
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• pp.261-279
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• 2017

Spectroscopic investigation of Si quantum dots (Si-QDs) embedded in silicon nitride was performed over a broad stoichiometry range to optimize light emission. Plasma-enhanced chemical vapor deposition was used to grow the $SiN_x$ films on Si (001) substrates. The film composition was controlled via the flow ratio of silane ($SiH_4$) and ammonia ($NH_3$) in the range of R = 0.45-1.0 allowed to vary the Si excess in the range of 21-62 at.%. The films were submitted to annealing at $1100^{\circ}C$ for 30 min in nitrogen to form the Si-QDs. The properties of as-deposited and annealed films were investigated using spectroscopic ellipsometry, Fourier transform infrared spectroscopy, Raman scattering and photoluminescence (PL) methods. Si-QDs were detected in $SiN_x$ films demonstrating the increase of sizes with Si excess. The residual amorphous Si clusters were found to be present in the films grown with Si excess higher than 50 at.%. Multi-component PL spectra at 300 K in the range of 1.5-3.5 eV were detected and nonmonotonous varying total PL peak versus Si excess was revealed. To identify the different PL components, the temperature dependence of PL spectra was investigated in the range of 20-300 K. The analysis allowed concluding that the "blue-orange" emission is due to the radiative defects in a $SiN_x$ matrix, whereas the "red" and "infrared" PL bands are caused by the exciton recombination in crystalline Si-QDs and amorphous Si clusters. The nature of radiative and no radiative defects in $SiN_x$ films is discussed. The ways to control the dominant PL emission mechanisms are proposed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.158-158
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• 2011

$Cu(In_xGa_{1-x})Se_2$ (CIGS) thin film solar cell is one of the most promising solar cells in photovoltaic devices. CIGS has a direct band gap which varied from 1.0 to 1.26 eV, depending on the Ga to In ratio. Also, CIGS has been studying for an absorber in thin film solar cells due to their highest absorption coefficient which is $1{\times}10^5cm^{-1}$ and good stability for deposition process at high temperature of $450{\sim}590^{\circ}C$. Currently, the highest efficiency of CIGS thin film solar cell is approximately 20.3%, which is closely approaching to the efficiency of poly-silicon solar cell. The deposition technique is one of the most important points in preparing CIGS thin film solar cells. Among the various deposition techniques, the sputtering is known to be very effective and feasible process for mass production. In this study, CIGS thin films have been prepared by rf magnetron sputtering method using a single target. The optical and structural properties of CIGS films are generally dependent on deposition parameters. Therefore, we will explore the influence of deposition power on the properties of CIGS films and the films will be deposited by rf magnetron sputtering using CIGS single target on Mo coated soda lime glass at $500^{\circ}C$. The thickness of CIGS films will be measured by Tencor-P1 profiler. The optical properties will be measured by UV-visible spectroscopy. The crystal structure will be analyzed using X-ray diffraction (XRD). Finally the optimal deposition conditions for CIGS thin films will be developed.

• 한국해양공학회지
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• 제13권4호통권35호
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• pp.151-158
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• 1999

A model harbour with Plan scale of $1.08{\times}1.08m$ is built on a tidal tank using a Froude relationship from a real harbour($432{\times}432m$). Velocity components are measured by a ultrasonic velocity meter and flow structure is then predicted using a 2-D depth integrated hydrodynamic model. In the finite difference model implemented in this study, various wall boundary conditions, i.e. no-slip, free-slip, partial-slip and semi-slip are used to represent turbulent diffusion terms, e.g. ${\partial}^2U_{ij}/{\partial}x^2\;or\;{\partial}^2U_{ij}/{\partial}y^2$. These conditions are focused to investigate their influence on the flow structure along the wall and basin of the harbour with aspect ratio of unity, i.e. Length/Breadth. Numerical experiments are compared with the measurements and used to analyse flow patterns in the basin during tidal cycles. It is shown from the results that no-slip closed boundary condition is the most appropriate method with respect to the location of the eddy centre, although the condition underestimates velocity components along the wall.

• Journal of Photoscience
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• 제11권2호
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• pp.71-74
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• 2004

The macrocycle L exhibited a switch on-off behavior through the fluorescent responses by aromatic imine molecule 1 (X=H) / trifluoroacetic acid (TFA). In the 'switch on' state, it was supposed that the aromatic imine molecule 1 is in the cavity of macrocycle L and a photoinduced electron transfer (PET) from the nitrogen of azacrown part to the anthryl group is inhibited by the interaction between the aromatic imine molecule 1 and the azacrown part of macrocycle L. In the 'switch off' state, it was supposed that the protonated imine molecule 1 is induced by the continuous addition of TFA and a repulsion between the protonated azacrown part and the protonated imine molecule 1 is occurred. It was considered that this process induces the intermolecular PET from the protonated imine molecule 1 to the anthryl group of macrocycle L because of a proximity effect between the anthryl group and the protonated imine molecule 1. From the investigation of the transient emission decay curve, the macrocycle L showed three components (3.45 ns (79.72%), 0.61 ns (14.53%), and 0.10 ns (5.75%). When the imine molecule 1 was added in the macrocycle L as molar ratio=1:1, the first main component showed a little longer lifetime as 3.68 ns (82.75%) although the other two components were similar as 0.64 ns (14.28%) and 0.08 ns (2.96%). On the contrary, when the imine molecule 3 (X=C1) was added in the macrocycle L as molar ratio=l:1, all the three components were decreased such as 3.27 ns (69.83%), 0.44 ns (13.24%), and 0.06 ns (16.93%). The fluorescent pH titration of macrocycle L was carried out from pH=3 to pH=9. The macrocycle L and C $U^{2+}$- macrocycle L complex were intersected at about pH=5, while the E $u^{3+}$ -macrocycle L complex was intersected at about pH=5.5. In addtion, we investigated the fluorescence change of macrocycle L as a function of the substituent constant ($\sigma$$_{p}$$^{o}$) showing in the para-substituent with electron withdrawing groups (X=F, Cl) and electron donating groups (X=C $H_3$, OC $H_3$, N(C $H_3$)$_2$), respectively, as well as non-substituent (X=H).).ctively, as well as non-substituent (X=H).

• Journal of Preventive Medicine and Public Health
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• 제32권2호
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• pp.123-129
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• 1999

1997년 3월부터 1998년 6월까지 충북대학교병원 내과에 입원하여 치료를 받은 폐암환자 98명과 암 아닌 다른 질환을 가진 대조군 98명을 대상으로 흡연, 음주, 여러 가지 질병과거력 등을 포함한 생활습관과, GSTM1과 GSTT1, 그리고 CYP1A1, CYP1E1 유전자 다형성 양상을 조사하여 다음과 같은 결론을 얻었다. 1. GSTM1의 결손은 환자군이 67.01%, 대조군이 58.16%로 확인되었으며, OR(95% CI)이 1.46(0.82-2.62)으로 폐암 발생에 대해 유의한 영향을 미치지 않는 것으로 나타났다. 2. GSTT1의 결손은 환자군이 58.76%, 대조군이 50.00%로 확인되었으며, OR (95% CD가 1.43(0.81-2.51)으로 폐암 발생과 관련이 없는 것으로 나타났다. 3. CYP1A1 유전자 다형성은 Ile/Ile, Ile/Val, Val/Val 환자군이 각각 59.18%, 35.71%, 5.10%, 대조군이 각각 52.04%, 45.92%, 2.04%로 CYP1A1 유전자 다형성과 폐암 위험도 사이의 관련성은 유의하지 않은 것으로 나타났다$(x^2trend=0.253,\;p-value>0.05)$. 4. CYP1E1 유전자 다형성은 c1/c1, c1/c2, c2/c2 형 이 환자군에서 각각 50.00%, 42.86%, 7.14%, 대조군에서 각각 66.33%, 30.61%, 3.06%로 CYP1E1 활성이 폐암 발생에 유의한 영향을 미치는 것으로 나타났다$(x^2trend=5.783,\;p-value<0.05)$. 특히 환자군이 대조군에 비하여 아주 드문 대립유전자인 c2형이 더 많은 것으로 나타났다. 5. 폐암과 밀접한 연관이 있는 흡연습관의 OR(95% CI)이 3.03(1.58-5.81)으로 확인되어, 폐암의 위험인자로 재확인 되었다. 6. GSTM1, GSTT1, CYP1A1, CYP2-E1과 흡연습관을 포함한 다변량 분석에서 흡연습관만이 유의한 폐암의 위험인자로 나타났다. 이 결과로부터 위의 4가지 유전자의 다형성이 폐암발생에 미치는 영향은, 흡연을 포함한 환경적 요인에 비하여 크지 않을 것으로 판단된다.

• Journal of Microbiology
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• 제45권6호
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• pp.510-514
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• 2007

Twenty-five bacterial strains that secrete mucous materials were isolated from sediment obtained from King George Island, Antarctica. Seven of these strains proved capable of producing cryoprotective exopolysaccharides. The strain KOPRI 21653 was selected for the further study of an anti-ice-nucleating polysaccharide (ANP), which originated from a polar region. KOPRI 21653 was identified as Pseudoalteromonas arctica as the result of 16S rRNA analysis. The exopolysaccharide, P-21653, was purified completely from the KOPRI 21653 cell culture via column chromatography and protease treatment. The principal sugar components of P-21653 were determined to be galactose and glucose, at a ratio of 1:1.5, via GC-MS analysis. The cryoprotective activity of P-21653 was characterized via an E. coli viability test. In the presence of 0.1% (w/v) P-21653, the survival ratio of E. coli cells was as high as 82.6% over three repeated freeze-thaw cycles. The survival ratio decreased drastically to 71.5 and 48.1 %, respectively, in five and seven repeated cycle conditions; however, the survival ratios were greater over three (96.6-92.1%) to seven (100.5-91.6%) freeze-thaw cycles in the presence of 0.5 and 1.0% (w/v) P-21653. In addition, at much lower concentrations (0.1-1.0%), P-21653 resulted in survival ratios (83.1-98.4%) similar to those of two commercially available cryoprotectants ($V_{EG}$ plus X-1000, 92.9% and $V_{M3}$, 95.3%), which were utilized at the recommended concentrations (90%). The biochemical characteristics of exopolysaccharide P-21653 reflect that this compound may be developed as a useful cryoprotectant for use in medical applications and in the food industry.

• 한국표면공학회지
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• 제49권5호
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• pp.454-460
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• 2016

Double-layered Al-Mg films have been deposited by using an e-beam deposition method on a cold-rolled steel sheet(CR), which the structure of the film was Al/Mg/CR. The micro-structure, alloy phase, and corrosion resistance of the Al-Mg coated CR were investigated before and after heat treatment at $400^{\circ}C$ for 2, 3, and 10 min in a nitrogen atmosphere. Total thickness of Al-Mg films was fixed at $3{\mu}m$ and the thickness ratio of Al and Mg layers(Al:Mg) has been changed from 5:1 to 1:5. The cross-sectional morphology of the films, which had the thickness ratio of 2:1(Al:Mg), 1:1, and 1:2, was changed after heat treatment from columnar to featureless structure. The x-ray diffraction data for as-deposited films showed only pure Al and Mg peaks. Al-Mg alloy peaks such as $Al_3Mg_2$ and $Al_{12}Mg_{17}$ phase appeared after the heat treatment. The Al-Mg coating with the thickness ratio of 1:1(Al:Mg) showed the best corrosion resistance of up to 500 hours by salt spray test.

• 대한토목학회논문집
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• 제8권2호
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• pp.135-145
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• 1988

본(本) 연구(硏究)는 재료(材料)의 배합(配合)이 단순한 mortar를 제작 그 균열발생을 관찰, 측정하여 정적하중(靜的荷重)에 의한 균열 및 일정진폭을 갖는 동적하중(動的荷重)에 의한 균열성장영역 예측을 시도한 것이다. 사용시편은 mortar의 배합비(配合比)와 물-시멘트비(比)를 달리하여 ASTM E 561-80에서 제안한 CLWL-DCB(crack-line-loaded-double-cantilever-beam)의 제1방법인 벽개형(劈開型)모드(opening mode)에 의거 균열성장거동을 측정하였다. 본(本) 실험(實驗)에서는 X-Y recorder에 나타난 하중(荷重)(P)-균열개구변위($2V_1$), 균열개구변위($2V_1$)-균열선단개구변위($2V_2$)의 diagram을 해석하여 정적하중(靜的荷重)에 의한 균열선단의 비선형적인 미소균열을 포함하는 유효균열길이(effective crack length; $a_e$)와 균열선단의 미소균열을 제외한 물리적균열길이(physical crack length; $a_m$) 및 replica 필름으로 구한 균열길이(replica crack length; $a_t$)의 상관관계와 일정진폭을 갖는 반복하중에 의한 $a_e$, $a_m$, $a_t$를 구하여 정적하중(靜的荷重)에 의한 균열특성과 동적하중(動的荷重)에 의한 균열특성을 조사한 것이다.

• 한국농공학회지
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• 제31권1호
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• pp.82-95
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• 1989

This study was carried out for the stability analysis of earth dam by the variation of compaction density. The test samples were taken from five kinds of soil used for banking material and the degree of compaction for this samples were chosen 100, 95, 90, 85, and 80 percent. The stability problems were analysed by the settlement and camber( extra banking) of dam, strength parameter and dam slope, and coefficient of permeability and seapage flow through dam body. The results of the stability analysis of earth dam are as follows. 1. The more the fine particle increases and lower the compaction degree becomes, the lower the preconsolidation load becomes but the compression index becomes higher. 2. Sixty to eighty percent of settlement of dam occurs during the construction period and the settlement ratio after completion of dam is inversly proportional to the degree of compaction. 3. The camber of dam has heigher value in condition that it has more fine particle(N) and heigher dam height(H) with the relation of H= e(aN-bH-e). 4. The cohesion(C) decreases in proportion to compaction degree(D) and fine particle(N) with the relation of C= aD+ bN-c, but the internal friction angle is almost constant regardless of change of degree of compaction. 5. In fine soil, strength parameter from triaxial compression test is smaller than that from direct shear test but, they are almost same in coarse soil regardless of the test method. 6. The safety factor of the dam slope generally decreases in proportion to cohesion and degree of compaction but, in case of coarse soil, it is less related to the degree of compaction and is mainly afected by internal friction angle. 7. Soil permeability(K) decreases by the increases of the degree of compaction and fine particle with relation of K=e(a-bl)-cN) 8. The more compaction thickness is, the less vertical permeability (Kv) is but the more h6rzontal permeability (KH) is, and ratio of Kv versus KH is largest in range from 85 to 90 percent of degree of corn paction. 9. With the compaction more than 85 percent and coefficient of permeability less than ${\alpha}$X 10-$^3$cm/sec, the earth dam is generally safe from the piping action.