http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Investigation of heterogeneous of ellipsoid particle interaction field using optical laser tweezers
최규환,강동우,박범준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
Heterogeneity among particles is their inherent feature, which makes the prediction of the properties of assembled structures and materials composed of many particles non-deterministic. Here, we report a promising strategy to quantify and visualize the field of heterogeneous and anisotropic interactions between non-spherical particles using the rotational measurement of optical laser tweezers. The mutual configuration and separation of two particles at an oil-water interface were optically controlled, and the corresponding capillary interaction behaviors were directly measured. As a result, the optimal particle configuration at an energetically favorable state was determined, depending on the interparticle distance. Visualization of the capillary field around individual particles demonstrated that the interface deformation by the presence of non-spherical particles and thus the capillary force were highly influenced by undulation of the meniscus as well as geodesic curvature.
Heterogeneous colloidal interactions field mapping method using optical laser tweezers
최규환,강동우,박범준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
Heterogeneity among particles is their inherent feature, which makes the prediction of the properties of assembled structures and materials composed of many particles non-deterministic. Here, we report a promising strategy to quantify and visualize the field of heterogeneous and anisotropic interactions between non-spherical particles using the rotational measurement of optical laser tweezers. The mutual configuration and separation of two particles at an oil-water interface were optically controlled, and the corresponding capillary interaction behaviors were directly measured. As a result, the optimal particle configuration at an energetically favorable state was determined, depending on the interparticle distance. Visualization of the capillary field around individual particles demonstrated that the interface deformation by the presence of non-spherical particles and thus the capillary force were highly influenced by undulation of the meniscus as well as geodesic curvature.
최규환,정호균 관광경영학회 2017 관광경영연구 Vol.79 No.-
The aims of this study is to analyze the tourism teaching style according to the profile of tourism students. A total of 800 questionnaires were distributed to the students, with 698 copies were used for data analysis. The result of empirical analysis showed that tourism teaching style is comprised of multidimensional structure with four factors of suggestive, assertive, facilitative and collaborative. Results founded that there were significant differences of tourism teaching style as preferred by male and female students. Male students were found to prefer more suggestive, facilitative, and collaborative than female students. But there were not significant differences of tourism teaching style between grade and age group. In addition, results of 1 sample t-test indicated that all male and female, and grade group students preferred the collaborative teaching style as the most highly preferred followed by suggestive and facilitative. Therefore, we have to consider extending the model of tourism teaching style-course satisfaction and academic achievement, and include gender and a form of universities in order to understand this model broadly. Theoretical and managerial implications based on findings are discussed.
최규환,강동우,박범준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
When polymer particles are dispersed in an organic solvent or solvent mixtures with moderate dielectric constants, such as cyclohexyl bromide (CHB, ε = 7.92), a relatively small amount of surface charges are produced, whereas charge screening occurs less. The resulting electrostatic repulsive force between the particles is stronger than it is in aqueous dispersions. In this study, we added n-decane to CHB to lower the refractive index of the solvent. The increased visibility of PMMA particles dispersed in the liquid medium enabled direct measurements of the repulsive force between the particles. We varied the volume fraction of n-decane in the medium and measured the magnitude changes in the interactive forces between paired particles with optical laser tweezers.