This research study explores the addition of chromium (Cr6+) ions as a nucleating agent in the alumino-silicate-glass (ASG) system (i.e., Al2O3-SiO2-MgO-B2O3-K2O-F). The important feature of this study is the induction of nucleation/crystallization in the base glass matrix on addition of Cr6+ content under annealing heat treatment (600 ± 10 °C) only. The melt-quenched glass is found to be amorphous, which in the presence of Cr6+ ions became crystalline with a predominant crystalline phase, Spinel (MgCr2O4). Microstructural experiment revealed the development of 200–500 nm crystallite particles in Cr6+-doped glass-ceramic matrix, and such type microstructure governed the mechanical properties. The machinability of the Cr-doped glass-ceramic was thereby higher compared to base alumino-silicate glass (ASG). From the nano-indentation experiment, the Young’s modulus was estimated 25(±10) GPa for base glass and increased to 894(±21) GPa for Cr-doped glass ceramics. Similarly, the microhardness for the base glass was 0.6(±0.5) GPa (nano-indentation measurements) and 3.63(±0.18) GPa (micro-indentation measurements). And that found increased to 8.4(±2.3) (nano-indentation measurements) and 3.94(±0.20) GPa (micro-indentation measurements) for Cr-containing glass ceramic.
Two kinds of solar thermal power generation systems (trough and tower) are selected as the research objects. The life cycle assessment (LCA) method is used to make a systematic and comprehensive environmental impact assessment on the trough and tower solar thermal power generation. This paper mainly analyzes the three stages of materials, production and transportation of two kinds of solar thermal power generation, calculates the unit energy consumption and environmental impact of the three stages respectively, and compares the analysis results of the two systems. At the same time, Rankine cycle is used to compare the thermal efficiency of the two systems.
This study evaluates the effectiveness of human resources (HR) practices on teaching and learning outcomes in primary education. The research was guided by four research questions and two research hypotheses. The study utilized a survey design via Google Forms for efficient data collection on human resources practices’ effectiveness in primary education. The questionnaire, validated by experts, garnered 60 responses within a month. Data analysis in Statistical Package for the Social Sciences (SPSS) included descriptive statistics and analysis of variance (ANOVA) techniques, adhering to ethical standards. The findings highlight the importance of HR practices that accommodate diversity, support inclusivity, and foster a sense of belonging for all students. Challenges in implementing inclusive HR practices are also identified, emphasizing the need for ongoing efforts to promote inclusivity and equity in primary education. The study concludes by advocating for the development and implementation of effective HR strategies to enhance teaching and learning outcomes in primary education.
The contraction of manufacturing economic activity in Latin American countries has been affected by the health crisis in the last few years. This phenomenon has negatively impacted the Latin American countries’ economies. In order to evaluate the impact of the manufacturing economy, this research integrates the impact of Foreign Direct Investment (FDI) on the growth of the Ecuadorian manufacturing sector, from 1981 to 2019, considering the role of the state through public spending using cointegration. The results are not consistent considering the empirical framework used; thus, FDI has a negative and significant influence on the manufacturing sector. Also, the manufacturing sector has a strong relationship with FDI in the short run and a less significant one in the long run. The results presented in this research suggest promoting domestic and FDI in the manufacturing sector, not only towards overexploited and monopolized sectors such as mining and telecommunications.
Using multiple evaluation methods and systems give a comprehensive assessment. A computer-based multiple-choice assessment system was designed, implemented, posted online, and used to assess students as part of their final evaluation marks for a discipline. The online system of evaluation was intended to be used multiple times for evaluating the assimilation degree of a specific course at the end of the course. The data recorded for the period 2017–2023 with about 1400 distinct users were used to analyze the performance of the evaluation system. The system worked fine and a slight modification of it served well on remote evaluation during COVID-19 period. However, the upturn of mobile phone applications requires the creation of a system adapted to the new virtual reality.
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