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Rock burst is a major disaster in deep mining, where bursting liability is an important indicator of rock burst risk. This study therefore intends to explore the impact of microwave thermal shock on rocks with strong bursting liability by testing the microwave thermal shock and uniaxial compression of typical hard brittle sandstone and analyzing their physical and mechanical properties and the response of bursting liability indicators after microwave thermal shock. The research results show that: (1) After microwaving, the surface temperature of the sandstone continues to rise with the increase of thermal shock time, until it breaks at 150 s; (2) Microwave thermal shock has a significant effect on the structural damage of sandstone. After 120 s of microwaving, the longitudinal wave velocity and elastic modulus decrease by 15.12 % and 8 % respectively. The AE signal density increases at each stage of uniaxial compression, and the maximum absolute energy at the final destruction of sandstone decreases by 42.3 %; The dynamic failure time of rock increases by 259 %, the impact energy index decreases by 95 %, and the elastic energy index decreases by 92 %. This research offer references for efficient rock breaking in deep earth engineering and prevention and control of rock burst in resource mining.

This paper focuses on the differences in crowding perception among different types of passengers in trains, aiming to optimize passenger experience and improve the level of service of urban rail transit. Based on data from a passenger survey on the Beijing subway, this paper introduces the concept of Crowding Perception Threshold (CPT) and analyzes the principle of passenger spatiotemporal crowding. Considering factors such as gender, age, travel purpose, and standing density of passengers, the paper constructs a quantitative model of crowding perception using the ordered logit model and proposes a method for classifying the level of service accordingly. The study results indicate that the CPTs for all types of passengers range from 91.8% to 101.6%, with the females, elderly individuals, and noncommuters showing greater sensitivity to crowding. In the temporal dimension, all types of passengers have higher CPTs during peak hours than during off-peak hours, influenced by passengers' crowding expectations. In the spatial dimension, the level of service for most types of passengers is considered crowded at standing densities of 6-7pax/m[sup.2] during peak hours, while the level of service for all types of passengers is deemed to be very crowded at 8pax/m[sup.2], at which point additional passengers are not recommended., Author(s): Xia Lu [1]; Baohua Mao (corresponding author) [1]; Min Wang (corresponding author) [2,3]; Yixin Zhao [1]; Peining Tian [1] 1. Introduction In some cities in China, the issue of [...]

This study aims to tackle the problem of frequent coal-rock dynamic events caused by local stress concentration in deep mining working face under high static stress environment. Specifically, by taking the deep working face of Hongqinghe Mine located in Xinjie Mining Area as an example for analysisthis paper investigates the geological conditions of No. 3-1coal seam that are affected by the mining method and the coal rock dynamic disaster events occurred during mining; utilizes numerical simulation to simulate the mining stress field and energy field of the stope; analyzes the potential coal burst instability area and mechanism of coal burst gestation and catastrophe in the stope during the mining of the No. 3-1103 working face; probes into the sources of catastrophic stress and influencing factors of coal-rock disasters in dangerous areas, puts forward targeted prevention and control measures. Results show that: ① the roof strata structure, goaf and coal pillar are the key factors influencing coal burst in the stope during the mining of the No. 3-1103 working face; ② the simulation results indicatethe location and characteristics of the coal burst instability area in the stope of the No. 3-1103 working faces, as well as the simulation outlines 5 strong coal burst areas and 11 medium coal burst areas presented in the stope; ③ Measures are proposed for coal burst during mining from the perspective of cutting off the dynamic load source, reducing static load stress concentration, and blocking the transmission of high concentration stress. Detailed measures include implementing multi-source prevention and control in areas with high static or high static+dynamic loads, implement pre-pressure off-load measures prior to mining, and local risk relief and coal burst prevention and reduction treatments during mining.

Pharmaceuticals and personal care products (PPCPs) are found in wastewater, and thus, the environment. In this study, current knowledge about the occurrence and fate of PPCPs in aquatic systems-including wastewater treatment plants (WWTPs) and natural waters around the world-is critically reviewed to inform the state of the science and highlight existing knowledge gaps. Excretion by humans is the primary route of PPCPs entry into municipal wastewater systems, but significant contributions also occur through emissions from hospitals, PPCPs manufacturers, and agriculture. Abundance of PPCPs in raw wastewater is influenced by several factors, including the population density and demography served by WWTPs, presence of hospitals and drugs manufacturers in the sewershed, disease burden of the population served, local regulations, and climatic conditions. Based on the data obtained from WWTPs, analgesics, antibiotics, and stimulants (e.g., caffeine) are the most abundant PPCPs in raw wastewater. In conventional WWTPs, most removal of PPCPs occurs during secondary treatment, and overall removal exceeds 90% for treatable PPCPs. Regardless, the total PPCP mass discharged with effluent by an average WWTP into receiving waters (7.35-20,160 g/day) is still considerable, because potential adverse effects of some PPCPs (such as ibuprofen) on aquatic organisms occur within measured concentrations found in surface waters.

Making clear the vibration response law of buildings(structures)due to blasting is of great significance both engineeringly and the economically. By conducting blasting experiment at subway station entrance A, the vibration signal of building NO.2 was analyzed through Hilbert-Huang transform. Results indicate that as height increases, the three-vector peak vibration velocity attenuate sharply, and then shows a wave-shaped change in the middle and amplify on the top floor, which was divided into attenuation area(0~26.15 m], fluctuation area(26.15~71.75 m]and amplification area(71.75~94.55 m]. The shape of the Hilbert spectrum gradually changes from three-peak to single-peak, the dominant frequency band attenuates from 75~125 Hz to 10~40 Hz and the energy amplitude decreases. This demonstrates that the lower vibration frequency of the floor in the amplification area could easily cause resonance. Based on the composition of the top-level energy spectrum fitted by the ground measuring points, it is verified that the essence of the top-level amplification effect is to selectively amplify the energy close to the natural frequency of the building in the blasting seismic wave.

Background: This study aims to elucidate characteristics of the symptom network of work–family conflict (WFC) and sleep disorders among Chinese correctional personnels while accounting for job burnout as a possible confounder. Method: A total of 472 correctional personnel were included. Their WFC, sleep disorders, and job burnout were measured using a Chinese version of Work–Family Conflict Scale (WFCS), the Athens Insomnia Scale (AIS), and a revised Chinese version of Maslach Burnout Inventory‐General Survey (MBI‐GS), respectively. Central symptoms and bridge symptoms were respectively identified based on centrality indices and bridge centrality indices. Network stability was examined using the case‐dropping procedure. Results: Daytime condition (strength = 0.01) and strain‐based work interference with family (WFCs, strength = 1.45) symptoms had the highest centrality values in the WFC‐sleep disorder network structure, which were also identified as two bridge symptoms. Emotional exhaustion, daytime condition, and WFCs appeared to be potential bridge symptoms in the WFC–sleep disorder–burnout network structure. Conclusions: In this study, among Chinese correctional personnel, daytime conditions, and WFCs were found to be central symptoms in the WFC–sleep disorder network structure, with emotional exhaustion as the bridge symptom in the WFC–sleep disorder–burnout network structure. We encourage relevant organizations to provide timely and effective education and guidance for regulatory personnel regarding these bridge symptoms. Subsequent research should follow up to assess the impact of relevant interventions on symptoms in the WFC–sleep disorder–burnout network, thereby advocating for the mental and physical health of correctional personnel. [ABSTRACT FROM AUTHOR]

This research systematically investigates the influence of raw material particle size and calcium content on the geopolymerization process to gain insight into the physical and mechanical properties of geopolymer gels, including setting time, fluidity, pore structure, compressive strength, and leaching characteristics of encapsulated Cr3+ heavy metal ions. Utilizing a diverse range of particle sizes of metakaolin (MK; 3.75, 7.5, and 12 µm) and fly ash (FA; 18, 45, and 75 µm), along with varied calcium levels, this study assesses the dual impact of these factors on the final properties of both metakaolin- and fly-ash-based geopolymers. Employing sophisticated analytical techniques such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR), the research meticulously documents alterations in chemical bonding, micro-morphology, and pore structures. Key findings reveal that reducing the size of MK and FA particles to 3.75 and 18 µm, respectively, enhances the compressive strength of their matrices by 128.37 and 297.58%, respectively, compared to their original values (63.59 and 33.87 MPa, respectively) at larger particle sizes. While smaller particle sizes significantly bolster compressive strength, they adversely affect slurry flow and reduce the leaching rates of Cr3+ from MK- and FA-based matrices, reaching 0.42 and 0.75 mg/L at 3.75 and 18 µm, respectively. Conversely, increased calcium content markedly enhances setting times and contributes to the formation of dense microstructures through the production of calcium aluminate silicate hydrate (C-A-S-H) gels, thus improving the overall curing performance and durability of the materials. These insights underline the importance of fine-tuning particle size and calcium content to optimize geopolymer formulations, offering substantial benefits for varied engineering applications and promoting more sustainable construction practices. [ABSTRACT FROM AUTHOR]

Chronic spontaneous urticaria (CSU) is a common and complex autoimmune disease characterized by cutaneous eruptions, usually poorly controlled and accompanied by persistent itching, which severely affects the quality of life of patients. The pathogenesis of CSU is not fully investigated, and mast cell activation by autoantibodies through the immunoglobulin E (IgE)-high affinity IgE receptor (FceR I) axis appears to be important in the disease process. In recent years, in addition to the anti-IgE antibody omalizumab (OMZ), many novel therapeutic biologies (NTBs) are emerging as potential adjunctive therapeutic drugs for CSU and other autoimmune diseases. In this paper, we review the mechanism, efficacy and safety of NTBs in CSU treatment. [ABSTRACT FROM AUTHOR]