Safety assessment of sand casting explosion accidents by testing cavity pressure of the sand mold to protect employee health.

Excessive cavity pressure may result in a sand casting explosion, and corresponding measures should be adopted to prevent these consequences. In this study, the pressure variations in the cavity were first investigated based upon on-site testing by taking the resin contents into consideration, and then the evolution characteristics of sand casting explosion accidents were analyzed in depth by system dynamics, chaos theory, and the bow-tie model. When the resin contents are 1.3 wt%, 1.4 wt%, and 1.5 wt%, the pressures of the gas vent increase by 27.0 Pa, 32.8 Pa, and 35.6 Pa, respectively. To reduce the pressure of the cavity, the resin content should be reduced. The evolutionary process of sand casting explosion accidents has a noticeable butterfly effect and randomness, whose occurrence is comprehensively affected by human, object, environment, management and emergency subsystems. The leading causes of sand casting explosion accidents mainly include the extensive gas evolution characteristics of foundry sand, cavity exhaust blockage, and inadequate safety monitoring. The leading consequences of sand casting explosion accidents mainly include casualties, secondary disasters, and social panic. The implications of these findings concerning sand casting explosion accidents can be regarded as the foundation for accident prevention in practice.

Heterogeneity and threshold effects of environmental regulation on health expenditure: Considering the mediating role of environmental pollution.

A comprehensive understanding of the heterogeneity and threshold effects of environmental regulation on health expenditure is essential for policy design and decision-making. This case study seeks to analyze the heterogeneity and threshold effects using panel data, which covers 30 Chinese provinces from 2007 to 2017. We examine the linear and nonlinear impacts of environmental regulation on health expenditure by using the Bayesian quantile regression and panel threshold regression, respectively. The empirical research results indicate a significant heterogeneous effect of environmental regulation on health expenditure in provinces where health expenditure falls in different quintiles. It shows mainly two effects: a positive effect of environmental regulation on health expenditure in provinces in the low quintiles and high quintiles of health expenditure; and a negative interrelationship between environmental regulation and health expenditure for provinces in the medium quintiles of health expenditure. A single threshold effect of environmental regulation on health expenditure is found to be different among three regions: the eastern, central and western regions. Specifically, in eastern and western China, the environmental regulations are stricter, and this helps reduce the health expenditures relating to environmental pollution. However, it was found that stricter environmental regulations do not reduce health expenditures in central China.

How do environmental regulation and foreign investment behavior affect green productivity growth in the industrial sector? An empirical test based on Chinese provincial panel data.

This study investigates the impact of environmental regulations (ERs) and foreign direct investment (FDI) on the green total factor productivity (GTFP) of the industrial sectors in 30 provinces in China by controlling human capital, technological innovation, energy structure, degree of opening up, and ownership structure for the period of 2004-2017. This not only helps to explain the influence path of ERs and FDI on green economic growth, but also effectively measures the moderating effect of ERs on technology spillover from FDI. The purpose of this paper is to explore the relationship between ERs, FDI and industrial GTFP from the perspective of regional heterogeneity, focusing on studying how ERs regulate the impact of FDI on GTFP. By constructing an influence mechanism of ERs and FDI on industrial GTFP, this study employs the feasible generalized least squares (FGLS) model and dynamic generalized method of moments (GMM) model to analyze the effects of ERs, FDI and their cross-terms on GTFP. The empirical results show that (1) the relationship between ERs and GTFP is not linear, but "U"-shaped and China is still in the left half of the "U"-shaped curve; (2) FDI flowing into China has a "pollution heaven" effect on the GTFP in the eastern and central regions while a "pollution halo" effect on the GTFP in the western region; (3) the strengthening of ERs weakens the negative effect of FDI on GTFP and plays a role in "screening" foreign investment; and (4) the spatial heterogeneity could affect the synergistic effect between ERs and FDI. Therefore, it is necessary for China to consider a series of environmental policies to "screen" inward FDI to ensure its move to a green economy benefits its own sustainable development by contributing to the increase in GTFP.