Quantitative Estimation of Pipeline Slope Disaster Risk in China

China’s economic development is closely related to oil and gas resources,and the country is investing heavily in pipeline construction.Slope geological hazards seriously affect the long-term safe operation of buried pipelines,usually causing pipeline leakage,property and environmental losses,and adverse social impacts.To ensure the safety of pipelines and reduce the probability of pipeline disasters,it is necessary to predict and quantitatively evaluate slope hazards.While there has been much research focus in recent years on the evaluation of pipeline slope disasters and the stress calculation of pipelines under hazards,existing methods only provide information on the occurrence probability of slope events,not whether a slope disaster will lead to pipeline damage.Taking the 2015 Xinzhan landslide in Guizhou Province,China,as an example,this study used discrete elements to simulate landslide events and determine the risk level and scope for pipeline damage,and then established a pipe-soil coupling model to quantitatively evaluate the impact of landslide hazards for pipelines in medium-and high-risk areas.The results provide a reference for future pipeline disaster prevention and control.

Facile synthesis and highly efficient selective adsorption properties of Y2Mo4O15 for methylene blue：Kinetics,thermodynamics and mechanical analyses

Y2 Mo4 O15 particles were prepared using a simple solution method（SSM） and used as a highly efficient selective adsorbent for methylene blue（MB） in aqueous solutions. The maximum adsorption capacity of the samples was determined based on the adsorption isotherms with different adsorbent doses at 298,318 and 338 K. The fittings of the temperature-dependent isotherms yield ΔrGm^θ=-34.1 kJ/mol,ΔrHm^θ-36.9 kJ/mol and ΔrSm^θ=-9.67 J/mol·K. The as-prepared Y2 Mo4 O15 has a very large maximum adsorption capacity（i.e., 198 mg/g） for MB at room temperature, and this value is only less than that of amorphous hardwood powder. Notably, 80 mg of adsorbent is able to completely decolorize 250 mL of 30 mg/L MB aqueous solution. The kinetic parameters of the adsorption process were obtained from the temperature-dependent adsorption isotherm（i.e., E1=26.9 kJ/mol and E1 = 63.8 kJ/mol）. The results of adsorption kinetics show that it is a pseudo-second-order reaction. The mechanism of the high selectivity and the large adsorption capacity is discussed based on competitive ion（CI） experiments and coordination theory.