Multi-walled carbon nanotubes (MWCNTs), widely recognized for their excellent electrical, thermal, and mechanical properties, have gained significant attention across various fields. However, aggregation due to their high Van der Waals force limits their processability and applications. Surface functionalization can offer a solution to these limitations and broadens their potential uses. Nevertheless, the low reaction rates of covalent functionalization in conventional batch reactors, caused by MWCNT aggregation, remain a significant challenge to overcome. Moreover, controlling the degree of functionalization in batch reactors is difficult. In this work, we demonstrated covalent functionalization of MWCNT with 4-bromoaniline to produce MWCNT-PhBr with high, controllable degrees of functionalization, using a customized packed-bed flow reactor. The reaction was performed under various conditions, including the reactant injection sequence, reaction time (1–3 h), temperature (60–80 ℃), and concentration of reactant (0.42–1.72 M). The resulting degree of functionalization was controlled within the range of 1.81–5.70 wt%. Notably, the highest degree of functionalization obtained under the optimized flow conditions (5.70 wt% at 70 °C and 1.72 M) represents a 2.11-fold increase compared to that achieved under the optimized batch conditions (2.70 wt% at 60 °C and 0.86 M). These results suggest that the flow system is an efficient and reliable method for synthesizing functionalized MWCNTs with the desired functional group content.

본 연구는 방사선학과 학생들을 대상으로 전공만족도가 진로결정몰입에 미치는 영향을 알아보고자 실시하였다. 구조화된 설문지를 사용하여 218명의 방사선학과 학생들을 대상으로 자가 보고식 조사를 실시하였다. 방사선과 학생들의 전공만족도는 ‘보통’ 정도였으며 진로결정몰입도는 ‘보통’에서 ‘미몰입’ 수준으로 1 학년에서 가장 낮게 나타났고 4학년에서 가장 높게 나타났다. 전공만족도는 진로결정몰입도에 영향을 주고 있었는데 특히, 하부요인인 전공 자부심이 진로결정 몰입에 가장 많은 영향을 주고 있었다. 본 연구에서 방사선학과 학생들의 진로결정몰입도는 미몰입 수준으로 낮게 나타나서 진로결정몰입도를 향상시킬 수 있는 방안이 필요한 것으로 보인다.

Urban Heat Island has become a serious problem in urban area. Tree is considered as effective measure for mitigating urban heat. The purpose of this study is reviewing urban heat island mitigation effect of tree, focusing on evaluation indices related to temperature reduction. We selected 49 previous studies and classified studies considering type of site and variables related to mitigate urban heat. Studies were classified as tree, vegetation, green roof/wall and green area. Variables of each group were categorized as space, function, individual and environment variables. Each study site showed different mitigation effects and considered different variables. Therefore, plans or designs for green area in urban area should consider differences among sites and use integrated evaluation indices including humidity and wind speed for mitigating urban heat.