Search

This study presents the synthesis and characterization of non-isocyanate polyurethanes (NIPU) derived from the copolymerization of cyclic-carbonated soybean oil (CSBO) and cyclic carbonate (CC)-terminated poly(ether carbonate) (RCC). Using a double-metal cyanide catalyst, poly(ether carbonate) polyol was first synthesized through the copolymerization of carbon dioxide and propylene oxide. The terminal hydroxyl group was then subjected to a substitution reaction with a five-membered CC group using glycerol-1,2-carbonate and oxalyl chloride, yielding RCC. Attempts to prepare NIPU solely using RCC and diamine were unsuccessful, possibly due to the low CC functionality and the aminolysis of RCC's linear carbonate repeating units. However, when combined with CSBO, solid NIPUs were successfully obtained, exhibiting good thermal stability along with enhanced mechanical properties compared to conventional CSBO-based NIPU formulations. Overall, this study underscores the potential of leveraging renewable resources and carbon capture technologies to develop sustainable NIPUs with tailored properties, thereby expanding their range of applications. [ABSTRACT FROM AUTHOR]

In this study, the Taguchi experimental design method using an L16 orthogonal array was attempted in order to investigate the optimal operating conditions for the CO2 methanation process in Ni-based catalysts. The relative influence of the main factors affecting CO2 conversion and CH4 yield was ranked as follows: reactor pressure > space velocity > reaction temperature. The optimal combination of operating conditions was a reactor temperature of 315 °C, a pressure of 19 bar, and a space velocity of 6000 h−1. The effect of the H2/CO2 ratio on CO2 conversion and CH4 yield was further considered under these optimal operating conditions. Moreover, the catalyst was characterized in order to investigate the production of coke through Brunauer–Emmett–Teller analysis, thermogravimetric analysis, and scanning electron microscopy. The amount of coke produced after the reaction for approximately 24 h was ~2 wt.%. Therefore, the desired CH4 yield and long-term operational stability were successfully obtained using the Taguchi design method and catalyst characterization. [ABSTRACT FROM AUTHOR]

Background: We aimed to provide the baseline data of nursing intervention for promoting the health promotion and promotion of growth and development for elementary students., Methods: By subjecting the 887 elementary students from 20 elementary schools located in the northern area of Gyeonggi-do Province, South Korea, data were gathered from April 10-May 30, 2017. The SPSS was used for analysis of data., Results: Some elements of emotional intelligence were found to differ depending on the gender and family type of lower-grade children, and depending on gender, sleep time, family type, and physical activity experience of higher-grade children. Some factors of stress were found to have differences according to sleeping time of the lower grades, and according to gender, sleeping time, family type, and whether they have experience in physical activity of higher-graders., Conclusion: It is possible to improve emotional intelligence and solve the stress of elementary students. This study will be the baseline data on developing the Health Promotion Education Arbitration Program for elementary students., Competing Interests: Conflict of interest The authors declare that there is no conflict of interests., (Copyright © 2021 Park et al. Published by Tehran University of Medical Sciences.)