• 한국세라믹학회지
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• 제54권3호
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• pp.211-216
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• 2017

ZnO nanopowder was synthesized using a relatively facile and convenient glycol process. ZnO nanopowder was successfully synthesized at temperatures as low as $125^{\circ}C$ using zinc acetate as the Zn source and 1,4-butanediol as the solvent. Then, the effects of water content on the growth process and morphological evolution of ZnO powders were investigated using 1,4-butanediol and water as binary solvent mixtures. Using pure 1,4-butanediol at a temperature above $125^{\circ}C$, the prepared hexagonal ZnO nanopowder exhibited a quasi-spherical shape with average crystalline size of approximately 30 - 50 nm. It is also demonstrated that the morphology of ZnO powders can be controlled by the addition of various water content in 1,4-butanediol. With increasing water content, the morphologies of the ZnO powders changed sequentially from quasi-spherical to hexagonal plate and pyramid, and finally to hexagonal prismatic with a pyramidal tip. A sharp peak centered at 384 nm in the UV region and a weak broad peak in the visible region between 450 and 700 nm were shown in the room temperature PL spectra of the ZnO synthesized using the glycol process, regardless of the addition of water, suggesting that ZnO nanopowders with the best crystallinity were obtained under these conditions.

• 한국표면공학회지
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• 제38권3호
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• pp.106-111
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• 2005

Ternary Ti-B-C coatings were synthesized on WC-Co and Si wafers substrates by a PECVD technique using a gaseous mixture of $TiCl_4,\;BCl_3,\;CH_4,\;Ar,\;and\; H_2$. The effects of deposition variables such as substrate temperature, gas ratio, $R_x=[BCl_3/(CH_4+BCl_3)]$ on the microstructure and mechanical properties of Ti-B-C coatings were investigated. From our instrumental analyses, the synthesized Ti-B-C coatings was confirmed to be composites consisting of nanocrystallites TiC, quasi-amorphous TiB2, and amorphous carbon at low boron content, on the contrary, nanocrystallites $TiB_2$, quasi-amorphous TiC, and amorphous carbon at relatively high boron content. The microhardness of the Ti-B-C coatings increased from $\~23 GPa$ of TiC to $\~38 GPa$ of $Ti_{0.33}B_{0.55}C_{0.11}$ coatings with increasing the boron content. The $Ti_{0.33}B_{0.55}C_{0.11}$ coatings showed lower average friction coefficient of 0.45, in addition, it showed relatively better wear behavior compared to other binary coatings of $TiB_2$ and TiC. The microstruture and microhardness value of Ti-B-C coatings were largely depend on the deposition temperature.

• 한국재료학회지
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• 제31권9호
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• pp.481-487
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• 2021

ZnO particles are successfully synthesized at 150 ℃ for 30 min using zinc acetate as the Zn source and 1,4-butanediol as solvent using a relatively facile and convenient glycol process. The effect of ammonium hydroxide amounts on the growth behavior and the morphological evolution of ZnO particles are investigated. The prepared ZnO nanoparticle with hexagonal structure exhibits a quasi-spherical shape with an average crystallite size of approximately 30 nm. It is also demonstrated that the morphology of ZnO particles can be controlled by 1,4-butanediol with an additive of ammonium hydroxide. The morphologies of ZnO particles are changed sequentially from a quasi-spherical shape to a rod-like shape and a hexagonal rod shape with a truncated pyramidal tip, exhibiting preferential growth along the [001] direction with increasing ammonium hydroxide amounts. It is demonstrated that much higher OH^- amounts can produce a nano-tip shape grown along the [001] direction at the corners and center of the (001) top polar plane, and a flat hexagonal symmetry shape of the bottom polar plane on ZnO hexagonal prisms. The results indicate that the presence of NH⁴⁺ and OH^- ions in the solution greatly affects the growth behaviors of ZnO particles. A sharp near-band-edge (NBE) emission peak centered at 383 nm in the UV region and a weak broad peak in the visible region between 450 nm and 700 nm are shown in the PL spectra of the ZnO synthesized using the glycol process, regardless of adding ammonium hydroxide. Although the broad peak of the deep-level-emission (DLE) increases with the addition of ammonium hydroxide, it is suggested that the prominent NBE emission peaks indicate that ZnO nanoparticles with good crystallization are obtained under these conditions.

• 여성건강간호학회지
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• 제27권3호
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• pp.196-208
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• 2021

Purpose: This study aimed to test the efficacy of a nurse-led postpartum self-care (NLPPSC) intervention at reducing postpartum fatigue (PPF) and depressive mood and promoting maternal functioning among first-time mothers in Bangladesh. Methods: A non-synchronized quasi-experimental design was used. First-time mothers were recruited during postpartum and assigned to the experimental or control group (34 each). The experimental group received the NLPPSC in the hospital, a 1-day intervention that focused on increasing self-efficacy. The control group received usual care. Data on PPF, depressive mood, maternal functioning, self-care behaviors, postpartum self-efficacy, and self-care knowledge were collected at postpartum 2 weeks (attrition 23.5%) and 6 weeks (attrition 16.1%). Data were analyzed using descriptive statistics, bivariate statistics, and linear mixed model analysis. Results: One-third (33.3%) of new mothers experienced depressive mood (Edinburgh Postnatal Depression Scale scores of ≥13 points). The NLPPSC intervention was statistically significant in decreasing PPF (β=-6.17, SE=1.81, t=-3.39, p<.01) and increased maternal functioning at postpartum 6 weeks in the experimental group (β=13.72, t=3.73, p<.01) compared to the control. Knowledge was also statistically significant for increased maternal functioning over time (β=.37, SE=.18, t=2.03, p<.05). However, there were no statistically significant differences in depressive mood over time. Conclusion: The NLPPSC intervention was feasible and effective in improving fatigue and maternal functioning in Bangladeshi mothers by postpartum 6 weeks and thus supports implementing the NLPPSC intervention for new mothers after childbirth.

• 여성건강간호학회지
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• 제27권4호
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• pp.278-285
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• 2021

Purpose: This study aimed to examine the effect of a newborn care education program using ubiquitous learning (UL-NCEP) on exclusive breastfeeding and maternal role confidence of first-time mothers in Vietnam. Methods: This quasi-experimental study with a nonequivalent control group design was conducted at a university hospital in Hue city, Vietnam, between June and July 2018. Eligible first-time mothers were conveniently allocated to the experimental (n=27) and the control group (n=25). Mothers in the control group received only routine care, whereas mothers in the experimental group received UL-NCEP through tablet personal computers in addition to routine care in the hospital. Then, the educational content was provided to mothers by their smartphone for reviewing at home. UL-NCEP was developed based on the World Health Organization's "Essential Newborn Care Course" guidelines. The exclusive breastfeeding rate and maternal role confidence level after birth and at 4 weeks postpartum were assessed in both groups to assess the effect of UL-NCEP. Results: At 4 weeks postpartum, the experimental group showed a significantly higher level than the control, for exclusive breastfeeding rate (p<.05) as well as mean maternal role confidence (p<.05). Conclusion: UL-NCEP was a feasible and effective intervention in increasing first-time Vietnamese mothers' exclusive breastfeeding rate and maternal role confidence level. This program may be integrated into routine care for postpartum mothers to promote mother and infant health among first-time mothers in Vietnam.

• 여성건강간호학회지
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• 제29권3호
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• pp.219-228
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• 2023

Purpose: Preterm birth is increasing, and obstetric nurses should have the competency to provide timely care. Therefore, training is necessary in the maternal nursing practicum. This study aimed to investigate the effects of practice education using a preterm-labor assessment algorithm on preterm labor-related knowledge and clinical practice confidence in senior nursing students. Methods: A pre-post quasi-experimental design with three groups was used for 61 students. The preterm-labor assessment algorithm was modified into three modules from the preterm-labor assessment algorithm by March of Dimes. We evaluated preterm labor-related knowledge, clinical practice confidence, and educational satisfaction. Data were analyzed with the paired t-test and repeated-measures analysis of variance. Results: The practice education using a preterm-labor assessment algorithm significantly improved both preterm labor-related knowledge and clinical practice confidence (paired t=-7.17, p<.001; paired t=-5.51, p<.001, respectively). The effects of the practice education using a preterm-labor assessment algorithm on knowledge lasted until 8 weeks but decreased significantly at 11 and 13 weeks after the program, while the clinical practice confidence significantly decreased at 8 weeks post-program. Conclusion: The practice education using a preterm-labor assessment algorithm was effective in improving preterm labor-related knowledge and clinical practice confidence. The findings suggest that follow-up education should be conducted at 8 weeks, or as soon as possible thereafter, to maintain knowledge and clinical confidence, and the effects should be evaluated.

• 대한화장품학회지
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• 제29권2호
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• pp.67-77
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• 2003

Two categories of cosmetic products, cosmetics and quasi-drugs, have been established by the Ministry of Health, Labor and Welfare (MHLW) in Japan. Japanese pharmaceutical law has defined that products categorized as cosmetics do not exhibit any effects on human skin. In fact, cosmetic products are not permitted to claim any efficacy. On the other hand, products in the quasi-drug category can claim several efficacies such as anti-inflammatory effects, whitening/lightning effects, hair growth effects and so on. Unfortunately, the Japanese MHLW has not yet approved the efficacy of anti-aging/anti-wrinkle effects as a claim point. However, the population is aging, and the demand for anti-aging/anti-wrinkle products is increasing year by year. Japanese cosmetic companies have proposed to the MHLW that anti-aging/anti-wrinkle agents be approved as a claim concept of a quasi-drug. However, unified evaluation methods for anti-aging/anti-wrinkle effects have not been established. Currently, each company evaluates the efficacy of products/materials using their own original methods. Thus, to request approval of the MHLW, the establishment of a unified evaluation method is needed. Consequently, the Japan Cosmetic Industry Association (JCIA) has established a task force to develop guidelines for evaluating anti-wrinkle effects in 1998. In conclusion, the JCIA would like to adopt visual and image analysis scales to evaluate the anti-wrinkle effects objectively. Generally, wrinkles are roughly classified into three groups as fine wrinkles, linear deep wrinkles and crow's feet. However, academic societies of dermatology or cosmetics have not yet established a definition of wrinkles in Japan. Thus, in advance of setting up an evaluation method, the definition of wrinkles f3r evaluation must be decided. Wrinkles are defined by the task force of the JCIA as follows; furrows that people can recognize visually and that appear on the forehead, the corners of the eyes and the backs of the neck with aging. In addition, furrows are emphasized by exposure to solar light and by dry conditions. Visual evaluation is the most sensitive method and can be applied to most types of wrinkles. However, visual evaluation is hard to express digitally as results. Besides, in the case of image analysis, comparisons of data obtained from distinct examinations can not be done, because data from image analysis are relative values. Thus, to enhance the reliability of the evaluations, the adoption of an objective scale was required. The principle of the evaluation method is to analyze images taken from silicone replicas of wrinkle areas using several parameters, such as the proportion of the wrinkle $area({\%})$, the mean depth of the wrinkles (mm), the mean depth of the deepest wrinkle (m) and the deepest point on the deepest wrinkle. Lights are shown on the skin replica from an orthogonal direction of the main orientation of the wrinkle, and the resulting shadow images are quantified by the image analysis method. To increase the precision of the data or to allow comparisons of independent examinations, a scale with furrows of several depths, 200, 400, 600, 800, and $1000{\mu}m$, is adapted in the evaluation system. I will explain the guidelines established by the JCIA in the presentation.

• 공연문화연구
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• 제40호
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• pp.5-35
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• 2020

정동(affect)은 신체가 외부 세계를 감각함으로써 생성되는 강렬함(intensity)과 특질(quality)이다. 이렇게 체험된 정동 중에서 의미와 해석이 부여된 관념이 감정(emotion)이다. 정동 이론(affect theory)은 감정과 정동을 분별하고 정동에 주목함으로써 신체의 반응과 변화를 분석할 수 있는 방법을 제공하고 있으며, 신체를 매체로 하는 공연예술 연구에 새로운 가능성을 제시하고 있다. 농악은 '재현'(representation)보다는 정동의 발생 자체에 주력하는 예술이다. 농악은 소리, 색깔, 질감, 신체 운동 등이 중첩되어 공감각적으로 현존하는 공연이다. 여기에는 인간의 신체를 중심으로 악기, 소품, 의상, 무대장치 등 물질적인 것들과 리듬, 기분, 분위기 등 비물질적인 것들이 동원된다. 신체는 이런 것들에 자극되어 공연에 적절하도록 경향성을 띄며, 공연에 몰입할수록 '이미지 없는 신체'(the body without an image)가 되어 '의사-신체성'(quasi-corporeality)을 보이며 행동한다. 마치 의식이 없는 것처럼 자동으로 움직이는 이런 신체는 집단 속에서 더 쉽게 나타난다. 일상의 개인을 집단 속의 '이미지 없는 신체'로 이행(transition)시키기 위해서 농악에서는 '진풀이'라는 집단적인 신체 운동을 수행한다. 이런 신체 운동은 비언어적인 교감과 소통을 높여 정동을 증강시키고, 상호 신뢰와 귀속감 속에서 개개인들의 창조력을 발휘하게 한다. 농악이 일으키는 정동과 감정은 자신과 집단의 존재, 활력, 능력을 확인하고 긍정하는 것으로 작용한다. 이런 긍정성은 집단의 차원에서 농악을 의미 있고 중요한 가치로 기억하게 하였고, 보존하고 전승해야 하는 공연양식으로 인식하게 하였다.

• 한국재료학회지
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• 제28권8호
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• pp.478-488
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• 2018

In this study, three kinds of steels are manufactured by varying the rolling conditions, and their microstructures are analyzed. Tensile and Charpy impact tests are performed at room temperature to investigate the correlation between microstructure and mechanical properties. In addition, heat affected zone(HAZ) specimens are fabricated through the simulation of the welding process, and the HAZ microstructure is analyzed. The Charpy impact test of the HAZ specimens is performed at $-40^{\circ}C$ to investigate the low temperature HAZ toughness. The main microstructures of steels are quasi-polygonal ferrite and pearlite with fine grains. Because coarse granular bainite forms with an increasing finish rolling temperature, the strength decreases and elongation increases. In the steel with the lowest reduction ratio, coarse granular bainite forms. In the HAZ specimens, fine acicular ferrites are the main features of the microstructure. The volume fraction of coarse bainitic ferrite and granular bainite increases with an increasing finish rolling temperature. The Charpy impact energy at $-40^{\circ}C$ decreases with an increasing volume fraction of bainitic ferrite and granular bainite. In the HAZ specimen with the lowest reduction ratio, coarse bainitic ferrite and granular bainite forms and the Charpy impact energy at $-40^{\circ}C$ is the lowest.

• 보건교육건강증진학회지
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• 제20권4호
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• pp.79-93
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• 2003

Childhood injuries are the primary cause of death and disability among children aged 5 to 14. Consistent practice of learned safety behaviors can reduce the occurrence of severe injuries among children. However, safety behavior concern is low among Korean-American children specifically and American children, in general. The objective of the study is to evaluate the impact of an unintentional injury prevention curriculum, Risk Watch among Korean-American children. A quasi-experimental design with a nonequivalent control group was used for the designed of the study. Two intervention and two control Korean schools in Atlanta participated in this study. The intervention consisted of weekly lessons in traffic, bicycle, pedestrian, and fire safety. One hundred and two students completed a pre-test and a post-test. The main outcomes were safety behaviors (seat belt use or helmet use), behavioral intentions, and safety knowledge. Analysis of covariance was used for the statistical analyses. Strong intervention effects were found for increasing knowledge of all safety topics in the intervention group. Additionally, statistically significant intervention effects were detected for increasing seat belt and helmet use, as well as behavioral intentions of wearing a seat belt and wearing a helmet, among pre-kindergarten and kindergarten students. For students in grades 1 and 2, intervention effects were found for increasing helmet use. Among students in grades 3 to 8, the intervention group showed statistically significant increases for seat belt use. Limitations of the study and recommendations for modifying and supporting unintentional injury prevention programs for school children are discussed.