After tunnel blasting, a large amount of CO will be produced and accumulated in the dead-end tunnel. If the ventilation discharge is not proper and the entry time into the dead-end tunnel is not appropriate, then it can cause workers to suffer from poisoning, hypoxia, and suffocation. Therefore, to understand the airflow and diffusion characteristics of CO in the dead-end tunnel after excavation and improve the working environment quality of the heading excavation tunnel, this paper uses numerical simulation and on-site verification to study the influence of different ventilation parameters on the airflow and CO diffusion characteristics in the dead-end tunnel after excavation and blasting. The research results show that the higher the air velocity of the duct, the smaller the distance between the duct and the working face, and the higher the hanging height of the duct, the easier it is for CO to be discharged from the dead-end tunnel. The larger the distance between the duct and the side wall, the more vortices there are in the dead-end tunnel and the more difficult it is to discharge CO from the tunnel. This study provides theoretical guidance for the research of the migration law of CO after tunnel blasting and has important value for ensuring a safe working environment and clean production in tunnel excavation.
20 December 2023 in Mining, Metallurgy & Exploration
The pollution of heavy metals in soil is a problem of great concern to international scholars today. This research investigates the current research activities in the field of soil heavy metal pollution remediation and discusses the current areas of research focus and development trends. We conducted a bibliometric analysis of the literature on soil heavy metal pollution remediation from 1999 to 2020. CiteSpace and Vosviewer were used to conduct document co-citation and cluster analyses on the collected data. The research was mainly carried out based on the following factors: chronological distribution, country and institution distribution, source journal analysis, keyword co-occurrence analysis, and reference co-citation analysis. China (2173, 28.64%) and the United States (946, 12.47%) are the top two countries in terms of the number of articles published, and Environmental Science and Pollution Research (384, 5.06%) and Science of the Total Environment (345, 4.55%) published the most articles. The Chinese Academy of Science (485) is the organization that has contributed the most to the total number of publications. Furthermore, based on a keyword co-word analysis with Vosviewer and CitesSpace, it was concluded that the applications of phytoremediation and biochar in the remediation of heavy metals in soil are current research hotspots. Additionally, future research should focus on repair mechanisms, the development of new repair technology and joint repair systems.
Of all mine disasters, fires are very threatening to mine safety and often lead to the most serious consequences. Research on mine fire prevention technology and theory has experienced significant growth and is attracting escalating academic interest and attention. However, dedicated literature reviews on this topic are scarce. For the purpose of uncovering the research characteristics and trends on mine fire prevention technology and theory, this paper employs bibliometric analysis using the Web of Science Core Collection database. This study presents a detailed analysis of relevant articles published between 2010 and 2022. An assessment of the influences of journals, countries, institutions, and authors was conducted through a citation analysis. Furthermore, this paper describes co-authorship networks among different countries, institutions, and authors. Lastly, a review of the mine fire prevention techniques and theories researched during this period was carried out through a keyword clustering analysis. Four main research topics in mine fire prevention research were identified: “mine fire control technology”, “mine fire occurrence mechanism”, “mine fire prediction technology”, and “mine fire monitoring technology”. Additionally, the theory study of spontaneous combustion and its underlying mechanisms may represent a potential focus for future research. These findings contribute to providing a solid foundation for future research endeavors in this field of fire prevention.
Landslide hazards on roadbed slopes pose significant safety risks, leading to casualties, property losses, and environmental damage. With the rapid expansion of global railway and highway construction, roadbed slope stability has become a critical research focus. However, systematic reviews and prospective studies based on bibliometric analysis in this field remain limited; such a lack is likely to lead to a lag in the theoretical development of the field. To address this gap, this study analyzes 453 papers from 2014 to 2023 using the Web of Science (WOS) core collection and tools like VOSviewer, CiteSpace, and Bibliometrix R. This study focuses on the following: (i) Visualizing research trends through knowledge graphs, covering document quantity, the authors, the countries, and the keywords. (ii) The objectives, the methods, specific objects, and the environmental conditions of the literature in this field are categorized and discussed, and the limitations of numerical simulation and other research shortcomings in this field are pointed out. (iii) Future research directions, focusing on the actual working conditions and utilizing advanced and flexible subroutine functions to simulate complex conditions with multi-physical field coupling, are discussed to ensure the accuracy of this research and the sustainability of road construction development. This paper can help scholars comprehensively and quickly understand the research status and hotspots in the field of roadbed slope research, with a view to providing theoretical support for future research and exploration.
In the process of uniaxial loading of rocks, the original temperature information of infrared radiation is easily submerged in the noise signal, which leads to distortion of the obtained infrared radiation response information. In this paper, we propose a multi-band pseudo-emissivity denoising algorithm. Based on the basic theory of infrared radiation, by separating the infrared temperature measurement from the emissivity of the measured object, we constructed an infrared multi-band temperature measurement vector group that does not involve the emissivity to reduce the noise interference caused by the infrared temperature measurement results and the emissivity. Under a loading experiment of rock under uniaxial compression, the change of infrared radiation (IR) characteristics with loading was observed. The research results show that the multi-band pseudo-emissivity algorithm could effectively denoise infrared images and, using the denoised rock surface MIRT, AIRT and IRV as indicators, the characteristics of infrared radiation change in the process of uniaxial compression loading and fracturing of real rocks were analyzed.