• Korean Chemical Engineering Research
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• 제43권1호
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• pp.140-145
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• 2005

The desulfurization abilities using GC/microreactor have been examined for $CuO-Fe_2O_3$ sorbents with respect to calcination temperatures of 700, 900 and $1,100^{\circ}C$. CuO was used as a main active component, $Fe_2O_3$ was used as an additive one and 25 wt% $SiO_2$ was used as a support. The desulfurization reaction temperature was $500^{\circ}C$ and the regeneration reaction temperature was $700^{\circ}C$. From the XRD results, the $CuFeO_2$ compound has been observed for the fresh sorbent calcined at $1,100^{\circ}C$ and the $CuFeS_2$ compound for the reacted sorbent calcined at $1,100^{\circ}C$. By the BET results, however any significant differences among sorbents calcined at the three different temperatures of 700, 900 and $1,100^{\circ}C$ haven't been observed. Especially CFS1 (CuO : $Fe_2O_3$ : $SiO_2$=67.5 wt% : 7.5 wt% : 25 wt%) sorbent calcined at $1,100^{\circ}C$ maintained about 10 g sulfur/100 g sorbent for 100 cycles by the cyclic test.

• Korean Security Journal
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• 제15호
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• pp.221-242
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• 2008

Protection is to maximize the protectee's physical security by minimizing the threats and minimizing the damages caused by the threats. From this point of view, the assassination case of Israel's former Premier Yitzhak Rabin who devoted himself to proceed peace process in Middle East, on November 4, 1995, gives us a lot of lessons on protection. At that time, Israeli society was chaotic with anti-Rabin and anti-government demonstrations which is against Rabin's peace process, and they openly threatened to assassinate Premier Rabin. However, Shin Bet, Israeli Protective Agency, didn't reacted against the assassination threats effectively. Also they have to try to secure friendly public to widen the width of selection in case of crisis and to secure the credibility of the organization. They have to prevent harmful activities in advance by securing wide intelligence networks to collect and analyze various protective intelligences and preparing proper protective countermeasures. Intelligence is a basic element in protection and any protective measures not supported by intelligence activities are not useful and effective. Potential attackers study their target thoroughly and make an elaborate plan before their attack. Advance team is required to conduct security measures on a basis of analysis of vulnerability and threat factors, and close protection team should be prepared for the changing situations with crisis-consciousness. Is security, 100% perfection is not possible. However, Shin Bet failed to analyze and approach to the existing threats. They forgot the fact that security environment reflects social situations. Protection agents should be conscious of the fact that today is different from yesterday. So we have to expect what is not expected when not expected.

• Clean Technology
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• 제14권3호
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• pp.166-170
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• 2008

In this study, imidazolium salt ionic liquid on amorphous silica was prepared and its catalytic performance in the cycloaddition of $CO_2$ with allyl glycidyl ether (AGE) to produce heterocyclic carbonate was investigated. The ionic liquid was generated on chloropropyl functionalized silica through the immobilization of imidazole. The prepared catalyst was characterized using a number of instrumental analysis including XRD, BET, $^{29}Si$ MAS-NMR and SEM. $^{29}Si$ MAS-NMR showed that the ionic liquid formed adduct with the chloropropyl groups attached to the silica surface. The immobilized ionic liquid showed very good catalytic activity for the cycloaddition of $CO_2$ with AGE, showing 55-61% of AGE conversion with over 85% of the carbonate selectivity at $80-120^{\circ}C$. Its AGE conversion and selectivity to the carbonate were even higher than the homogeneous analog, 1-n-butyl-3-methyl imidazolium bromide (BMImBr).

• Journal of Korean Academy of Nursing
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• 제15권3호
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• pp.74-80
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• 1985

This study was attempted to identify the difference between body image of the patients with lower limb fracture and that of normal persons, and to examine if supportive group care could offer an apportunity for positive change in body image of the patient with lower limb fracture under the Quasi-experimental design. The subjects for this study were obtained by ta-king convenient sample of soldiers; the experimental group were 44 lower limb fractured patients hospitalized on the orthopedic Surgery unit in S Army General Hospital, while the control group were 44 normal enlisted men serving in the B Army regiment. Supportive group nursing care was given to the lower limb fractured patients who belong to the experimental group. Pre-and post-tests were administered to the experimental and the control group. The instruments to measure body image of the subjects were body Cathexis Scale developed by Scord and Jourard (1953) and Body Meaning Scale dove-loped by the reseacher. The reliability coefficients by Cronhach's u-test were .95 in body Cathexis Scale and .89 in Body Meaning Scale in this study. Data for this study were collected over a period 12 days from the 12th to the 24th of October, 1984 by the questionnaire. Data were analyzed by computer. Frequency, Percentage and x²-test were used to examine general chacteristics of the subjects. t-test was used to analyze the hypotheses. Analysis of variance was used to test difference in body image between groups classified by the general characteristics. Pearson Correlation Coefficient was used to identify the correlation between Body Cathexis Scale and Body Cathexis Scale and Body Meaning Scale. The results of this study were as follows: 1. No significant difference was found between the experimental and the control group on general characteristics of the subjects (p> .05). 2. Hypothesis I:“There will be a difference in body image between patiens with lower limb fracture and normal persons,”was supported(Body Cathexis t=6.91, p<.001, Body Meaning t=5.66, p< .001). 3. Hypothesis Ⅱ;“The will be a difference in body image of patients with lower limb fracture bet-ween after and before, supportive group nursing care was provided,”was supported (Body Cathexis t=5.90, p<.001, Body Meaning t=4.45, p <.001). 4. There was no significant difference in body image between groups classified by the general characteristics (p> .05). 5. The correlation between Body Cathexis Scale and Body Meaning Scale: It was reported that Body Cathexis Scale correlated with Body Meaning Scale in total subjects of the experimental and control group (r=.744, p<.001). That is, there was relatively high correlation between two scales. body Cathexis Scale correlated with Body Meaning Scale in the experimental group(r=.738, p <.001) and in the control group (r=.352, p <.001). That is, there was more than moderate correlation between two scales. In conclusion, it was found that there was a difference in body image between patients with lower limb fracture and normal persons, and supportive group nursing care offered an opportunity for positive change in body image of the patient with lower limb fracture.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.157.1-157.1
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• 2011

선택적 CO 산화반응(PrOx)에 사용되는 촉매 중 Pt, Ru, Rh 등의 귀금속 계 촉매들은 비귀금속 계 촉매에 비해 활성이 좋은 반면 가격이 비싸다는 경제적인 제한점이 있다. 따라서 소량의 귀금속을 사용하여 높은 활성의 촉매를 제조하고자 활성금속의 고분산 담지 방법에 대한 연구가 이루어지고 있다. 본 연구에서는 담체인 ${\gamma}-Al_2O_3$ 표면에 활성금속인 Pt의 고분산 담지를 위해 증착-침전법(Deposition-precipitation)을 적용하였으며 용액의 pH 변화에 따른 Pt 금속 입자의 분산도에 대한 영향을 살펴보았다. Pt의 함량은 1wt%로 고정하였고 침전제로 NaOH를 사용하여 용액의 pH를 pH 7.5 ~ 10.5로 변화시켰다. 제조된 촉매는 세척 후 $400^{\circ}C$, 3시간 소성 하였다. 제조된 1wt% Pt/$Al_2O_3$ 촉매의 특성분석을 위해 BET, TPR, CO-chemisorption을 수행하였다. PrOx 반응 실험은 GHSV=60,000 $ml/g_{cat}{\cdot}h$, $T=100{\sim}200^{\circ}C$, ${\lambda}$=4 조건에서 수행되었으며 반응 전에 촉매는 $400^{\circ}C$, 3시간 환원 후 사용하였다. 촉매의 특성분석과 PrOx 반응 실험 결과를 통해 촉매가 담체 위에 고분산 되는 최적의 pH를 확인할 수 있었으며, 기존의 함침법으로 제조된 촉매와 성능 비교를 통해 제조방법에 따른 영향을 살펴보았다.

• Applied Chemistry for Engineering
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• 제20권6호
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• pp.658-662
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• 2009

In this work, the amine-treated activated carbon nanotubes (A-MWNTs) were used to investigate the $CO_2$ adsorption behaviors. A-MWNTs were prepared by impregnation with amine in methanol after chemical activation methods using a KOH. The characteristics of amine-treated A-MWNTs were studied by X-ray photoelectron spectroscopy (XPS), $N_2$ adsorption, desorption isotherms at 77 K. The specific surface area and pore volume of the A-MWNTs were analyzed by BET equation, BJH method, and t-plot method. $CO_2$ capture capacity as a function of temperature was measured by temperature programmed desorption (TPD). From the results, the amine treatment increased the basicity and nitrogen content of the A-MWNTs. The $CO_2$ adsorption capacity of the amine-nontreated A-MWNTs showed the highest value at room temperature and then greatly decreased with increasing the temperature. However, the amine-treated A-MWNTs presented a softer slope with temperature compared to the amine-nontreated ones. It was due to the strong interactions between $CO_2$ and amino groups presented on the carbon surfaces studied.

• Journal of the Korea Institute of Military Science and Technology
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• 제6권3호
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• pp.54-61
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• 2003

$SnO_2$ gas sensor for the detection DMMP, simulant of nerve gas was fabricated and its characteristics were examined. Sensing materials were $SnO_2$ added by TEX>$\alpha$-$Al_{2}O_{3}$ with 0∼20wt.% and $In_{2}O_{3}$ with 0∼3wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Its dimension was 7$\times$10$\times$0.6$\textrm{mm}^2$. Crystallite size 8t phase identification, specific surface area and morphology of fabricated $SnO_2$ powders were analyzed by X-ray diffraction(XRD), surface area analyzer(BET) and by a scanning electron microscope(SEM), respectively. Sensor was measured as flow type and sensor resistance change was monitored as real time using LabVIEW program. The best sensitivities were 75% at adding 4wt.% TEX>$\alpha$-$Al_{2}O_{3}$, operating temperature $300^{\circ}C$ and 87% at adding 2wt.% $In_{2}O_{3}$, operating temperature $350^{\circ}C$ to DMMP 0.5ppm. Response and recovery times were about 1 and 3 min., respectively. Repetition measurement was very good with $\pm$3% in full scale. As a result, operating temperature was lower TEX>$\alpha$-$Al_{2}O_{3}$ than $In_{2}O_{3}$, but sensitivity was higher $In_{2}O_{3}$ than $\alpha$-$Al_{2}O_{3}$.

• Clean Technology
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• 제22권2호
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• pp.82-88
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• 2016

The loss of activity by coke is an important cause of catalyst deactivation during industrial operation. In this study, hydrogen ratio of reaction condition, which has influenced on coke formation over Pt-Sn catalyst, and regeneration of catalysts activity by coke burning, Pt sintering of coke burning as coke contents, effects of coke formation and deactivation with different Sn contents were confirmed. Pt-Sn-K catalyst supported on θ-alumina and γ-alumina was prepared progressively. Activity of regenerated catalyst for propane dehydrogenation was compared with fresh catalyst by coke burning, after propane dehydrogenation was carried out with different hydrogen ratio at 620 ℃ on fresh catalyst. Regenerated catalyst’s physical characterization such as BET, coke analysis and XRD was investigated. Through catalytic activity test and characterization, Sn contents of catalyst and hydrogen ratio in feed stream could affect coke formation on catalyst surface. Excessive coke makes loss of activity and Pt sintering during air regeneration process.

• Journal of the Mineralogical Society of Korea
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• 제31권1호
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• pp.47-55
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• 2018

Talc, hydrous magnesium phyllosilicate, is one of the most popular industrial minerals due to their chemical stability and adsorptivity. While micro-sized talc has long been used as a filler and coating, nano-sized talc recently is attracting attention as additives for improving the stability of nanocomposites. In this study, we produced the nano-sized talc powder by mechanical method using high energy ball mill and investigated the changes in particle size and crystallinity with increasing milling time up to 720 minutes. X-ray diffraction results show that the peak width of talc gradually as the milling proceeded, and after 720 minutes of pulverization, the talc showed an amorphous-like X-ray diffraction pattern. Lase diffraction particle size analysis presents that particle size of talc which was ${\sim}12{\mu}m$ decreased to ${\sim}0.45{\mu}m$ as the milling progressed, but no significant reduction of particle size was observed even after grinding for 120 minutes or more. BET specific surface area, however, steadily increases up to the milling time of 720 minutes, indicating that the particle size and morphology change steadily as the milling progressed. Scanning electron microscope and transmission electron microscope images shows that layered particles of about 100 to 300 nm was aggregated as micro-sized particles after pulverization for 720 minutes. As the grinding time increases, the particle size and morphology of talc continuously change, but the nano-sized talc particles form micro sized agglomerates. These results suggest that there is a critical size along the a, b axes in which the size of plates is reduced even though the grinding proceeds, and the reduction of plate thickness along the c axis leads the increase in specific surface area with further grinding. This study could enhance the understanding of the mechanism of the formation of nano-sized talc by mechanical grinding.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권9호
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• pp.390-396
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• 2019

This study was undertaken to analyze factors influencing the emotional labor and emotional intelligence of a dental hygienist on organizational effectiveness. The study was conducted between September 4, 2018 to December 7, 2018, enrolling a total of 233 dental hygienists living in the Jeollabuk-do province. The data were analyzed by independent t-test, one-way ANOVA, $Scheff{\acute{e}}$ test, Pearson's correlation coefficient, and stepwise multiple regression, using SPSS 18.0. The regression model obtained was F=138.917, P<0.05, with an explanatory percentage of 58.2. Emotional labor (${\beta}=0.608$) was determined to be the most influential variable among independent variables, and other factors affecting the organizational effectiveness of a dental hygienist include the highest level of education, career, and emotional intelligence. We conclude that in order to improve organizational effectiveness among dental hygienists, it is necessary to establish an effective plan for reducing emotional labor and promote emotional intelligence.