Mechanically enhanced supramolecular carbon nanotube (CNT) films were prepared in water by employing the π-electronrich phenyl, naphthalenyl, and pyrenyl end-functionalized polyethylene oxides (PEOs) as supramolecular linkers, followed by vacuum filtration. Among them, the supramolecular CNT film produced by the pyrenyl end-functionalized PEO (PEOPy) exhibited the highest mechanical strength, which was ~ 1.5–2 times higher than that of the CNT films produced using the typical dispersant, Triton X-100, although the functionality of PEO-Py was lower than that prepared using other linkers, and the content of PEO-Py in the CNT films was lower than that obtained using Triton X-100. Fluorescence and UV–Vis spectroscopy demonstrated that the improved mechanical properties of the supramolecular CNT film result from the formation of π–π interactions between the CNT and the pyrene moieties of the PEO-Py linker. Finally, the supramolecular CNT film exhibited a 40–50 dB electromagnetic shielding efficiency through hybridization with silver nanowires.

As the concept of “marriage age” gradually disappears, the consumption class of the wedding market includes not only X and Y generations but also Z generations, and each generation has its own characteristics as it is already known, and there are differences in the consumption. So this research analyzed age-related behavior differences in both awareness of and preparation for marriage. Three hundred sixteen unmarried Korean males and females comprised the study population and data was collected from March 5, 2019, to April 3, 2019. The SPSS Statistics 23.0 Package was used for analysis, specifically the functions of frequency, cross tabulation, factor analysis, chi-squared test, Cronbach’s alpha, Duncans’s new multiple range test (MRT), and analysis of variance (ANOVA). Marriage motivation was analyzed by three factors, and there were significant differences in two types. Marital involvement was analyzed by two factors, and both factors showed significant age-related differences. Concerns relating to marriage preparation were analyzed by four factors, and two varied according to respondent age. Regarding marriage preparation behaviors, the analysis revealed that the marriage preparation method appreciably differed between age groups. Our analysis also found significant age-related differences in “the main media usually used to acquire information” and “the paths preferred for acquiring information in preparing for marriage”. We expect that study results will be useful for identifying new research directions, understanding the dimensions of the wedding industry, and developing related marketing strategies.

올레핀/파라핀 분리를 위해 silver nanoparticle을 운반체로 이용하는 촉진수송막이 최근 많은 관심을 받고 있다. 기존 연구에서는 silver nanoparticle의 전구체로서 AgBF4가 사용되어 왔다. 하지만 상대적으로 고가에 속하는 AgBF4는 상업화에 적합하지 않기 때문에 비교적 저렴한 AgClO4를 전구체로 이용해 제조된 silver nanopaticle를 활용해서 PEBAX-5513/AgNPs (전구체: AgClO4)/7,7,8,8-tetracyanoquinodimethane (TCNQ) 복합막이 제조되었다. 그러나 여러 조성의 복합막이 제조되었으 나 올레핀 분리성능은 관찰되지 않았다. FT-IR 분석 결과는 PEBAX-5513 고분자 내에서 silver nanoparticle이 형성되고 TCNQ에 의해 표면이 양극성화 되는 것을 확인하였지만 형성된 silver nanoparticle이 안정화 되지 못한 것으로 분석되었다. 이러한 결과들을 통해 은염 전구체의 음이온이 올레핀/파라핀 분리막에서 중요한 역할을 하는 것으로 판단되었다.

본 연구는 대학생의 계획된 우연 기술이 진로적응성과 진로준비행동에 미치는 영향을 확인 하고 계획된 우연 기술의 향상을 위한 진로코칭 교육의 필요성에 대해 논의하는 것을 목적으로 진행하였다. 이를 위하여 본 연구는 서울 소재 4년제 대학교에 재학 중인 3, 4학년 학생 256명의 설문조사 결과를 분석하였다. 본 연구의 결과는 다음과 같다. 첫째, 대학생의 계획된 우연 기술은 진로적응성에 정적인 영향을 미치는 것으로 나타났다. 계획된 우연 기술의 호기심, 인내심과 낙관성 요인은 진로적 응성에 정적인 영향을 미치는 것으로 확인되었으며 낙관성 요인은 진로적응성의 모든 하위요인들에 정적인 영향이 있음을 확인하였다. 둘째, 대학생의 계획된 우연 기술은 진로준비행동에 정적인 영향을 미치는 것으로 확인되었다. 계획된 우연 기술의 호기심, 낙관성과 위험감수 요인은 진로준비행동에 정적인 영향을 미치는 것으로 나타났으며 호기심, 인내심, 낙관성과 위험 감수 요인은 진로준비행동의 하위요인들에 부분적으로 영향을 미치는 것으로 확인되었다. 대학생의 계획된 우연 기술을 향상하기 위하여 기존의 진로코칭 프로그램과 더불어 진로코칭 교육의 확대 실시가 필요하다고 사료된다. 아울러 이에 대한 대학 당국과 교수자들의 이해와 실천에 대해 제언하고자 한다.

In the present study, rutile phase titanium dioxide nanoparticles (R-TiO2 NPs) were prepared by hydrolysis of titanium tetrachloride in an aqueous solution followed by calcination at 900℃. The composition of R-TiO2 NPs was determined by the analysis of X-ray diffraction data, and the characteristic features of R-TiO2 NPs such as the surface functional group, particle size, shape, surface topography, and morphological behavior were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, and zeta potential measurements. The average size of the prepared R-TiO2 NPs was 76 nm, the surface area was 19 m2/g, zeta potential was −20.8 mV, and average hydrodynamic diameter in dimethyl sulfoxide (DMSO)–H2O solution was 550 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological observations revealed that R-TiO2 NPs were cytocompatible with oral cancer cells, with no inhibition of cell growth and proliferation. This suggests the efficacy of R-TiO2 NPs for the aesthetic white pigmentation of teeth.

In this study, activated carbon with well-developed mesopores was fabricated using kenaf short fibers as a representative biomass. Concentrated phosphoric acid was selected as an activation agent to create highly developed porous structures, and pore development was observed to occur in relation to the weight ratio of phosphoric acid and kenaf. The pore characteristics of the kenaf-based activated carbon were determined using the N2/ 77K adsorption isotherm, and its microcrystalline structure was analyzed using X-ray diffraction. The highest specific surface area (1570 m2/g) was observed when the weight ratio of phosphoric acid to kenaf was 3:1, and the highest mesopore fraction (74%) was observed at 4:1. The carbonization yield was 45–35%, which is higher than that of commercial activated carbon. The production of porous carbon material by this method offers high potential for application because it can be controlled over a wide range of average pore diameter from 2.48 to 5.44 nm.

Petroleum-based impregnating pitches were prepared from pyrolysis fuel oil (PFO) using a two-step heat treatment without a separation process. The pressurized heat treatment, the first step, was used to improve the properties of the pitches and enhance the product yield by promoting the cracking and polymerization of the components in the PFO. An atmospheric heat treatment as the second step was used only to synthesize the impregnating pitches from the liquid pitches prepared during the first step. The prepared impregnating pitches had the properties of a commercial petroleum-based impregnating pitch. The impregnation performance was evaluated by HT-XRD and an impregnation test. The HT-XRD results showed changes in the stacked structure of the pitches at the impregnation temperature. The bulk density of the carbon block was increased to 14.3% and the porosity was reduced by 10.3% after the impregnation/recarbonization process. The high reaction temperature during the first step induced the formation of quinoline insoluble (QI) components during the second step of the treatment, and the QI components adversely affected the impregnation process.

To meet the current demand in the fields of permanent magnets for achieving a high energy density, it is imperative to prepare nano-to-microscale rare-earth-based magnets with well-defined microstructures, controlled homogeneity, and magnetic characteristics via a bottom-up approach. Here, on the basis of a microstructural study and qualitative magnetic measurements, optimized reduction conditions for the preparation of nanostructured Sm-Co magnets are proposed, and the elucidation of the reduction-diffusion behavior in the binary phase system is clearly manifested. In addition, we have investigated the microstructural, crystallographic, and magnetic properties of the Sm-Co magnets prepared under different reduction conditions, that is, H2 gas, calcium, and calcium hydride. This work provides a potential approach to prepare high-quality Sm-Co-based nanofibers, and moreover, it can be extended to the experimental design of other magnetic alloys.

Highly active, stable and low-cost noble metal-free electrocatalysts are essential for production of hydrogen. However, preparation of such catalysts is still highly challenging so far. In this work, the Mo2C– carbon nanomaterials have been prepared by controlled thermal technique. By controlling concentration of the reactants in the experimental condition, the Mo2C– carbon nanomaterials have been fabricated, which leads to decreases in contact resistance b/w Mo2C– carbon nanomaterials and graphitic carbon atoms. As a result, the Mo2C– carbon nanomaterial electrode shows remarkable activity for hydrogen evolution reactions with a small onset overpotential of 95 mV, a Tafel slope of 62 mV dec−1, an high exchange current density of 0.32 mA cm−2, good stability during long-term 1000 cycles and exhibits long-term durability for several days. This study opens a new method for the preparation of highly active non-noble electrode for production of hydrogen from water splitting.