We develop a relatively cheap technology of processing a scrap in the form of already used tungsten-containing products (spirals, plates, wires, rods, etc.), as well not conditional tungsten powders. The main stages of the proposed W-scrap recycling method are its dispersing and subsequent dissolution under controlled conditions in hydrogen peroxide aqueous solution resulting in the PTA (PeroxpolyTungstic Acid) formation. The filtered solution, as well as the solid acid obtained by its evaporation, are used to synthesize various tungsten compounds and composites. Good solubility of PTA in water and some other solvents allows preparing homogeneous liquid charges, heat treatment of which yield WC and WC–Co in form of ultradispersed powders. GO (Graphene Oxide) and PTA composite is obtained and its phase transition in vacuum and reducing atmosphere (H2) is studied. By vacuum-thermal exfoliation of GO–PTA composite at 170–500℃ the rGO (reduced GO) and WO2.9 tungsten oxide are obtained, and at 700℃—rGO–WO2 composite. WC, W2C and WC–Co are obtained from PTA at high temperature (900–1000℃). By reducing PTA in a hydrogen atmosphere, metallic tungsten powder is obtained, which was used to obtain sandwich composites with boron carbide B4C, W/B4C, and W/(B4C–W), as neutron shield materials. Composites of sandwich morphology are formed by SPS (Spark-Plasma Sintering) method.
In this paper advanced Sentiment Analysis techniques were applied to evaluate public opinions reported by rail users with respect to four major European railway companies, i.e., Trenitalia and Italo in Italy, SNCF in France and Renfe in Spain. Two powerful language models were used, RoBERTa and BERT, to analyze big amount of text data collected from a social platform dedicated to customers reviews, i.e., TrustPilot. Data concerning the four European railway companies were first collected and classified into subcategories related to different aspects of the railway sector, such as train punctuality, quality of on-board services, safety, etc. Then, the RoBERTa and BERT models were developed to understand context and nuances of natural language. This study provides a useful support for railways companies to promote strategies for improving their service.
With the advancement of modernization, commoditization and grassroots governance have become important terms. Community governance not only promotes modern democracy but plays a key role in improving community governance capabilities and modernizing the governance system, which is receiving much attention. Despite the expanding number of articles on community governance, few evaluations investigate its evolution, tactics, and future goals. As a result, the particular goal of this study is to provide the findings of a thematic analysis of community governance research. Investigating the skills and procedures needed for practice-based community government. Data for this study were gathered through a thematic assessment of 66 papers published between 2018 and 2023. The pattern required by the researchers was provided by the ATLS.ti23 code used to record the review outcomes. This study proposes six central themes: 1) rural advancement, 2) community (social) capital, 3) public health and order governance, 4) governance technology, 5) sustainable development, and 6) governance model. The research results show that the research trend of community governance should focus on rural advancement, taking rural community governance as the starting point, the dilemma and adjustment of the governance model, community public health and order governance, and digital governance. It will yield new insights into new community governance standards and research trends.
Remote sensing technologies have revolutionized forestry analysis by providing valuable information about forest ecosystems on a large scale. This review article explores the latest advancements in remote sensing tools that leverage optical, thermal, RADAR, and LiDAR data, along with state-of-the-art methods of data processing and analysis. We investigate how these tools, combined with artificial intelligence (AI) techniques and cloud-computing facilities, enhance the analytical outreach and offer new insights in the fields of remote sensing and forestry disciplines. The article aims to provide a comprehensive overview of these advancements, discuss their potential applications, and highlight the challenges and future directions. Through this examination, we demonstrate the immense potential of integrating remote sensing and AI to revolutionize forest management and conservation practices.
In casting industries, issue of spent molding sand disposal is the origin of molding sand reclamation. Among from all reclamation concepts the thermal reclamation method is better for no-bake sand system. This study focuses on the evaluation of sand quality by considering physical and chemical characteristics of molding sand, which is reclaimed by thermal reclamation method. Electric fuel and fluidization mechanism is used in thermal reclamation system. Effect of reclamation temperature, soaking period and sand quantity on % reclamability, grain size, ADV and on LOI is investigated. The average grain size, low ADV, low LOI and acceptable % reclamability of thermally reclaimed sand are studied.
The main reason for the formation of nano-biotechnology is due to the penetration of nanotechnology in the biological field, nanotechnology research center is the study of nano-drug carrier. Nano-drug system targeted drug delivery to achieve drug release, increase the insoluble drugs and peptide drug bio-efficiency, reduce the toxicity and application of drugs and other aspects of the development of good prospects, and thus become one of the key research in recent years’ field. Synthesis and application of nanometer drug carriers this review is presented in recent years and its application to provide a comprehensive basis for the treatment process. Describes the nature and preparation of nano-drug carrier methods, in recent years, people have been widely concerned by scholars. Compared with the nano-drug delivery, the general pharmaceutical cannot have to extend the role of drugs, strong efficacy, and the advantages of small drug response. Nano-materials, the specific surface area, surface activity, high catalytic efficiency, surface active center, adsorption capacity and other characteristics, which has many excellent features and new features.
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