The tunable conduction of coumarin-based composites has attracted considerable attention in a wide range of applications due to their unique chemical structures and fascinating properties. The incorporation of graphene oxide (GO) further enhances coumarin properties, including strong fluorescence, reversible photodimerization, and good thermal stability, expanding their potential use in advanced technological applications. This review describes the developmental evolution from GO, GO-polymer, and coumarin-based polymer to the coumarin-GO composite, concerning their synthesis, characterization, unique properties, and wide applications. We especially highlight the outstanding progress in the synthesis and structural characteristics along with their physical and chemical properties. Therefore, understanding their structure-property relations is very important to acquire scientific and technological information for developing the advanced materials with interesting performance in optoelectronic and energy applications as well as in the biomedical field. Given the expertise of influenced factors (e.g., dispersion quality, functionalization, and loading level) on the overall extent of enhancement, future research directions include optimizing coumarin-GO composites by varying the nanofiller types and coumarin compositions, which could significantly promote the development of next-generation polymer composites for specific applications.
This article presents the validation of a virtue-based leadership development questionnaire (LID). Leadership is defined as the human action of guiding others toward a common good, which requires the exercise of personal competencies and virtues. The theoretical and factorial structure of LID has three domains: intellectual, relational and performative. The LID was administered to a sample of 1759 university students from Mexico and Spain for factor analysis. Subsequently, it was applied to a sample of 1906 students from a Mexican university for confirmatory factor analysis and to 171 Mexican students for a convergent validity study with the Socially Responsible Leadership Scale (SRLS). Psychometric analyses indicate that the questionnaire is reliable and valid. Confirmatory factor analysis indicates that the questionnaire fits the theoretical model and has convergent validity with the SRLS. This questionnaire aims to contribute to the leadership education of university students.
This review provides an overview of the importance of nanoparticles in various fields of science, their classification, synthesis, reinforcements, and applications in numerous areas of interest. Normally nanoparticles are particles having a size of 100 nm or less that would be included in the larger category of nanoparticles. Generally, these materials are either 0-D, 1-D, 2-D, or 3-D. They are classified into groups based on their composition like being organic and inorganic, shapes, and sizes. These nanomaterials are synthesized with the help of top-down bottom and bottom-up methods. In case of plant-based synthesis i.e., the synthesis using plant extracts is non-toxic, making plants the best choice for producing nanoparticles. Several physicochemical characterization techniques are available such as ultraviolet spectrophotometry, Fourier transform infrared spectroscopy, the atomic force microscopy, the scanning electron microscopy, the vibrating specimen magnetometer, the superconducting complex optical device, the energy dispersive X-ray spectrometry, and X-ray photoelectron spectroscopy to investigate the nanomaterials. In the meanwhile, there are some challenges associated with the use of nanoparticles, which need to be addressed for the sustainable environment.
Paraffin wax is the most common phase change material (PCM) that has been broadly studied, leading to a reliable optimal for thermal energy storage in solar energy applications. The main advantages of paraffin are its high latent heat of fusion and low melting point that appropriate solar thermal energy application. In addition to its accessibility, ease of use, and ability to be stored at room temperature for extended periods of time, Nevertheless, improving its low thermal conductivity is still a big, noticeable challenge in recently published work. In this work, the effect of adding nano-Cu2O, nano-Al2O3 and hybrid nano-Cu2O-Al2O3 (1:1) at different mass concentrations (1, 3, and 5 wt%) on the thermal characteristics of paraffin wax is investigated. The measured results showed that the peak values of thermal conductivity and diffusivity are achieved at a wight concentration of 3% when nano-Cu2O and nano-Al2O3 are added to paraffin wax with significant superiority for nano-Cu2O. While both of those thermal properties are negatively affected by increasing the concentration beyond this value. The results also showed the excellence of the proposed hybrid nanoparticles compared to nano-Cu2O and nano-Al2O3 as they achieve the highest values of thermal conductivity and diffusivity at a weight concentration of 5.0 wt%.
With the continuous development of network has also greatly developed, exploring the role of social network relationships and attachment emotions on consumer intention helps community managers to promote community purchases for more consumer. As another core component of social e-commerce, social media influencer also has a significant influence on consumer intention. This study systematically analyzed the effects of social network relationships and social media influencer characteristics on consumer purchase intentions. Introduced consumer attachment and perceived value as mediating variables to construct the research framework of this study. This article adopts quantitative analysis methods to test the research hypotheses proposed. This article collected 600 first-hand data in the form of a survey questionnaire and analyzed the data using AMOS and SPSS statistical software. The empirical analysis in this article confirms that social network relationships has a significant impact on consumer purchase intentions; social media influencer characteristics has a significant impact on consumer purchase intentions; consumer attachment has a significant impact on perceived value; consumer attachment plays a mediating role in the effect of social network relationships on consumers purchase intentions; perceived value plays no mediating role in the effect of social media influencer characteristics on consumer purchase intentions; perceived value plays a mediating role in the effect of consumer attachment on consumer purchase intentions; consumer attachment and perceived value have a chain mediating role between social network relationships and consumer purchase intentions.
Cross-border ecological cooperation is always a challenging issue. Ecological cooperation in the Guangdong-Hong Kong-Macao Greater Bay Area has its own uniqueness as it is cross-border cooperation under “One Country, Two Systems”, which is different from multinational cooperation or regional collaboration within one country. This paper analyses the cooperation documents of Guangdong, Hong Kong and Macao, official reports and academic literature, and then summarises the unique pattern of ecological cooperation in the Greater Bay Area under “One Country, Two Systems”. It outlines four characteristics: different priorities in ecological management of each side, case by base cooperation, government-dominated cooperation with low public participation, and huge institutional gap between three sides. This article also identifies several problems and causes: lack of common ecological targets for each side and effective cross-border regulative measures, cumbersome coordination in cross-border cooperation. Finally, four feasible recommendations have been put forwarded: creating new institutional arrangements under the context of “One Country, Two Systems”, establishing the efficient decision-making platform for the inter-city cooperation, introducing the market-based resource allocation, and encouraging public participation in ecological monitoring.
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