Numerical study of strain development in high-density polyethylene geomembrane liner system in landfills using a new constitutive model for municipal solid waste

Tensile strain development in high-density polyethylene (HDPE) geomembrane (GMB) liner systems in landfills was numerically investigated. A new constitutive model for municipal solid waste (MSW) that incorporates both mechanical creep and biodegradation was employed in the analyses. The MSW constitutive model is a Cam-Clay type of plasticity model and was implemented in the finite difference computer program FLAC?. The influence of the friction angle of the liner system interfaces, the biodegradation of MSW, and the MSW filling rate on tensile strains were investigated. Several design alternatives to reduce the maximum tensile strain under both short- and long-term waste settlement were evaluated. Results of the analyses indicate that landfill geometry, interface friction angles, and short- and long-term waste settlement are key factors in the development of tensile strains. The results show that long-term waste settlement can induce additional tensile strains after waste placement is complete. Using a HDPE GMB with a friction angle on its upper interface that is lower than the friction angle on the underlying interface, increasing the number of benches, and reducing the slope inclination are shown to mitigate the maximum tensile strain caused by waste placement and waste settlement.     

江西省水系连通及水美乡村建设试点县实施方案编制存在的问题及对策

为提高水系连通及水美乡村建设试点县实施方案编制质量，更好地参加全国竞争性立项，本文分析研究了江西省55个水系连通及水美乡村建设试点县实施方案和相应的专家评审意见，对实施方案编制过程中存在的符合性、完整性不够，实施范围情况调查不准等七个方面突出问题进行梳理剖析，并提出相应对策，可为实施方案编制提供参考。     

新时代背景下电力精准扶贫模式研究及建议

发挥电力行业优势特点,开展电力精准扶贫,对打赢脱贫攻坚战具有十分重要的作用,并能够助推脱贫攻坚与乡村振兴战略有效衔接.本文从电力扶贫在脱贫攻坚的重要作用出发,以“三聚焦”“三优先”“三模式”“三保障”为指引,详尽梳理并总结了电力精准扶贫主要模式和经验.在此基础上,深刻剖析了当前电力扶贫面临的困难及问题,提出电力精准扶贫的策略,以期为下一步开展电力精准扶贫提供参考与借鉴.     

基于现场监测与数值模拟的浅层采空区稳定性分析

隐患采空区是目前影响露天开采矿山安全生产的主要危害源之一。随着台阶开采的不断剥离,露天开采境界内各台阶与地下空区群的隔离层厚度越来越薄,随时有可能发生采空区顶板坍塌事故。考虑到露天矿采空区地质赋存条件和围岩稳固性等特征,以弓长岭露天铁矿浅层采空区为工程背景,运用现场监测和数值模拟相结合的手段综合分析了浅层采空区的稳定性。将液体静力水准地表沉降监测系统的监测数据与FLAC数值模拟结果对比,调整蠕变参数使得数值模拟的蠕变速率与现场监测结果一致,而后据此进行未来结果的预测。最终根据地表沉降数据确定的蠕变参数取值为A=1.0×10^-12、m=1.75、n=0.35。研究表明:静力水准测点地表最大沉降位移为-9.8 mm,蠕变计算结果顶板最大垂直位移约20.4 mm,应力最大值约25 MPa,综合分析显示该采空区较稳定。上述研究提供了一种基于采空区现场监测数据的数值模拟蠕变分析方法,可为类似矿山采空区稳定性分析提供借鉴。     

问题意识与理性思辨的结晶--评刘文良《绿色与安全:生态包装设计论》

《绿色与安全:生态包装设计论》是当前少有的专门研究生态包装设计的学术专著。该著对于生态包装的概念、生态包装设计的困惑与对策、食品药品等重要民生品包装设计的安全策略、方法与技术等重要理论与实践问题进行了深入探讨,尤其在科学界定生态包装的内涵、理性思辨关于生态包装的某些不合理"常识"以及与时俱进的学术与实践视野方面取得了重要建树。其鲜明的问题意识、务实的研究思路、严谨的求真精神在这部学术专著中得到了印证,为生态包装设计指明了方向、提供了遵循,堪称一把打开生态包装设计大门的"金钥匙"。     

Secure and reliable data communication in developing regions and rural areas

Nowadays, despite the ever increasing need of people for staying “connected” at any time and everywhere, in many areas of the world data connection is extremely expensive or even absent. The Global System for Mobile Communication (GSM) network virtually covers all the populated areas of the world and on average, the entire world population have a handheld device capable of accessing at least the GSM services. Therefore, it makes sense to consider the Short Message Service (SMS) as the most popular wireless data service for such devices. In this work, we exploit the SMS as mechanism for data transfer, especially in scenarios where there is no other network coverage than GSM, such as in rural areas and developing regions. In particular, we propose a framework, based on the SMS as transport facility, which enables secure end-to-end data communication in a ubiquitous and pervasive manner. Moreover, we investigated how, by using compression techniques, the overall processing and transmission efforts needed for secure data communication can be effectively reduced, with the obvious consequences also in terms of energy consumption on the involved devices. Finally, we successfully tested the effectiveness of the proposed framework within the context of a proof of concept implementation.     

Geosynthetic-sheet pile reinforced foundation for mitigation of earthquake and tsunami induced damage of breakwater

Earthquake and tsunami impose great threats on the stability of a breakwater. Foundation of the breakwater is weakened by these forces, and it may result in collapse of the breakwater. Lateral flow of seabed soils take place beneath the breakwater, and excess pore water pressure is generated in the foundation by an earthquake that precedes tsunami. These factors may lead to excessive settlement and horizontal displacement of the breakwater. Tsunami introduces additional instability to the deformed breakwater. Due to water level difference between seaside and harborside of the breakwater during a tsunami, seepage occurs through its foundation, and it may cause pipping of seabed soils. Tsunami induced scouring of mound is also a big problem for the stability of the breakwater foundation. Finally, these result in failure of the breakwater foundation. Due to failure of its foundation, the breakwater may collapse and cannot block the tsunami. It results in entering of the tsunami in coastal areas. In order to make a breakwater resilient against earthquake and tsunami induced damage, reinforcing countermeasures were developed for foundation of a breakwater. Geogrid, gabions and sheet piles were used for reinforcing a foundation model. The effectiveness of the model is evaluated through physical modeling for mitigating the earthquake and tsunami induced damage. Shaking table tests were performed to determine the effectiveness of the reinforced model under different earthquake loadings. Tsunami overflow test was conducted on the same deformed model in order to see the effects of tsunami on the model. Comparisons were made between the unreinforced and reinforced foundations, and it was observed during the tests that the reinforced foundation performed well in reducing the damage of the breakwater brought by the earthquake and tsunami. Overall, this study is useful for practice engineering, and the reinforced foundation model can be adopted for designing a breakwater foundation to reduce damage triggered by an earthquake and tsunami in the future.     

Predicting the settlement of geosynthetic-reinforced soil foundations using evolutionary artificial intelligence technique

In order to ensure safe and sustainable design of geosynthetic-reinforced soil foundation (GRSF), settlement prediction is a challenging task for practising civil/geotechnical engineers. In this paper, a new hybrid technique for predicting the settlement of GRSF has been proposed based on the combination of evolutionary algorithm, that is, grey-wolf optimisation (GWO) and artificial neural network (ANN), abbreviated as ANN-GWO model. For this purpose, the reliable pertinent data were generated through numerical simulations conducted on validated large-scale 3-D finite element model. The predictive power of the model was assessed using various well-established statistical indices, and also validated against several independent scientific studies as reported in literature. Furthermore, the sensitivity analysis was conducted to examine the robustness and reliability of the model. The results as obtained have indicated that the developed hybrid ANN-GWO model can estimate the maximum settlement of GRSF under service loads in a reliable and intelligent way, and thus, can be deployed as a predictive tool for the preliminary design of GRSF. Finally, the model was translated into functional relationship which can be executed without the need of any expensive computer-based program.     

Determinant factors of individuals’ decision to emigrate in rural Spain: The role of ICT-based public policies

Depopulation is a dramatic problem in rural inland Spain. The present study draws on a survey administered to inhabitants of rural areas to analyse the factors influencing the decision to emigrate to larger centres of population, with a special focus on the impact of ICT-based public policies. The findings show that size of municipality, age and education affect the intention to emigrate. It is found that the digital divide in terms of quality of ICT access has not, in many cases, been overcome, having an effect on citizen satisfaction. To guide public actions, we identify population profiles depending on both level of satisfaction with ICT development and preference towards specific ICT-related public policy measures intended to combat depopulation. We also find that most individuals continue to think that improving investment in ICT infrastructures should be a priority of public policy, compared to more advanced measures such as bolstering e-government.     

去除水中黄药的试验研究

为给选矿废水中残余黄药的去除提供依据，分别采用自然曝晒法、漂白粉氧化法、酸化分解法、亚铁沉淀法、活性炭吸附法对配制的黄药水溶液进行了黄药降解试验，结果表明，以上诸方法均能较彻底地去除溶液中的黄药，使水中的黄原酸盐浓度达到国家排放标准。其中亚铁沉淀法、漂白粉氧化法药剂来源容易，价格便宜，工艺简单，效果好，较适合处理含黄药选矿废水。