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.

National unity is a matter of great concern for many countries around the world today. The study of policy evaluation is an important aspect of the study of national unity. The evaluation of policy implementation effects can help policymakers analyze whether there are problems in the formulation and implementation of the policy, thereby promoting further policy adjustments to better achieve national unity. This article adopts thematic searches and a systematic literature review as research methods. Through the systematic review, it summarizes and analyzes the research on national unity policies across different regions and countries. The article has two objectives: First, to explore the current perspectives in the research on national unity policies, and second, to analyze the state of research regarding the effectiveness of national unity policies. Among the 35 papers analyzed, 7 were on integration policy, 6 were on education policy and 4 were on language policy. To a certain extent, this reflects the perspectives of some countries in Europe, Asia and Africa, including France, Greece, Russia, Turkey, China, Sri Lanka, Nepal, Kenya, South Africa, Nigeria and other countries on the governance of national unity. Research on policy effectiveness is mainly conducted from the perspectives of policy content and policy implementation. However, there is little analysis of successful cases that achieved the desired goals. The main contributions of this article are as follows: first, it summarizes and identifies the characteristics of national solidarity-related policies in different continents and countries. Secondly, the experience of the success and failure of the national unity policy is studied and summarized. In addition, this article also found that there are still gaps in the research on successful experiences and causes.

Research on community resilience has been ongoing for decades. Several studies have been carried out on resilience in different groups and contexts. However, few address the relationship between community resilience and depopulated rural areas. This study aims to dig deeper into this, considering the concrete impact of population decline in Spain. We carried out a systematic review of the most relevant contributions. A search protocol was developed and used to consult ten databases. Different combinations of terms such as ‘community resilience’, ‘rural’, and ‘depopulation’, or related terms, were used. 22 scientific texts were analysed. We obtained a set of publications that demonstrate the heterogeneity of research methods, approaches and analytical processes applied to the study of this relationship. A mostly qualitative approach was observed, either as the main technique or complementary to documentary reviews. The results underscore the complex nature of rural depopulation and related constructs. It emphasizes the specific importance of community resilience in these territories in terms of social capital, endogenous resources, sustainability, economic dynamism, local responsibility and effective governance. The findings identify a scarce mention to social intervention professions, which should have a more important role due to their core values. In the studies reviewed, it appears as an emerging and scientifically relevant area to explore, both for investigation and intervention purposes. The strength of a multidisciplinary approach to addressing the phenomena appears in the discussion as a main potential line of research.

In today’s manufacturing sector, high-quality materials that satisfy customers’ needs at a reduced cost are drawing attention in the global market. Also, as new applications are emerging, high-performance biocomposite products that complement them are required. The production of such high-performance materials requires suitable optimization techniques in the formulation/process design, not simply mixing natural fibre/filler, additives, and plastics, and characterization of the resulting biocomposites. However, a comprehensive review of the optimization strategies in biocomposite production intended for infrastructural applications is lacking. This study, therefore, presents a detailed discussion of the various optimization approaches, their strengths, and weaknesses in the formulation/process parameters of biocomposite manufacturing. The report explores the recent progress in optimization techniques in biocomposite material production to provide baseline information to researchers and industrialists in this field. Therefore, this review consolidates prior studies to explore new areas.

The study of authoritarian leadership has undergone significant development, with researchers exploring its different dimensions and consequences. This leadership style, characterized by a top-down approach and centralized decision-making authority, has been extensively examined in psychology, organizational behavior, and management literature. Scholars have delved into the effects of authoritarian leadership on various aspects of organizations such as employee satisfaction, motivation levels, productivity rates, turnover rates, and team dynamics. The research landscape surrounding authoritarian leadership has witnessed a recent surge in interest as scholars strive to understand its intricate connections with different variables. The primary objective of this study is to conduct a comprehensive bibliometric analysis on authoritarian leadership, aiming to identify the key research areas, influential authors, prominent journals in the field, and citation patterns. To our knowledge, no bibliometric analysis on authoritarian leadership can be found in the Scopus database, highlighting the novelty of our research. Through a source-based examination of scholarly articles and their citations pertaining to authoritarian leadership, this analysis offers valuable insights into the current state of research in this domain. By focusing on publications from the past decade onwards, we aim to uncover trends and potential gaps within existing literature while also providing guidance for future research endeavors. Our research findings will provide valuable insights into the phenomenon of authoritarian leadership, contributing to a deeper understanding of its implications. By delving into this topic, we hope to pave the way for future studies and investigations in this field that can build upon our findings and expand knowledge even further.