Waste management under multiple complexities: inexact piecewise-linearization-based fuzzy flexible programming

To tackle nonlinear economies-of-scale (EOS) effects in interval-parameter constraints for a representative waste management problem, an inexact piecewise-linearization-based fuzzy flexible programming (IPFP) model is developed. In IPFP, interval parameters for waste amounts and transportation/operation costs can be quantified; aspiration levels for net system costs, as well as tolerance intervals for both capacities of waste treatment facilities and waste generation rates can be reflected; and the nonlinear EOS effects transformed from objective function to constraints can be approximated. An interactive algorithm is proposed for solving the IPFP model, which in nature is an interval-parameter mixed-integer quadratically constrained programming model. To demonstrate the IPFP's advantages, two alternative models are developed to compare their performances. One is a conventional linear-regression-based inexact fuzzy programming model (IPFP2) and the other is an IPFP model with all right-hand-sides of fussy constraints being the corresponding interval numbers (IPFP3). The comparison results between IPFP and IPFP2 indicate that the optimized waste amounts would have the similar patterns in both models. However, when dealing with EOS effects in constraints, the IPFP2 may underestimate the net system costs while the IPFP can estimate the costs more accurately. The comparison results between IPFP and IPFP3 indicate that their solutions would be significantly different. The decreased system uncertainties in IPFP's solutions demonstrate its effectiveness for providing more satisfactory interval solutions than IPFP3. Following its first application to waste management, the IPFP can be potentially applied to other environmental problems under multiple complexities.     

Is There a Generic Environmental Advantage for Starch–PVOH Biopolymers Over Petrochemical Polymers?

The current study was undertaken to address the general question of whether there is an environmental advantage for renewable, starch?Cpolyvinyl alcohol (PVOH) biopolymer blends over petrochemical polymers. This was addressed using life cycle assessment (LCA) over a set of multiple case studies based on a consistent set of parameters and methodological background. A group of starch?CPVOH blended biopolymers derived from different feedstocks (wheat, potato, maize) were compared with high density polyethylene (HDPE), low density polyethylene (LDPE) and expanded polystyrene (EPS) in a range of applications. The results suggest that a general environmental advantage does not exist for the starch?CPVOH blended biopolymers over their petrochemical counterparts in all applications and, instead, a case-by-case approach is necessary to evaluate environmental pros and cons, based on specific comparisons. Overall, starch?CPVOH biopolymers were found to offer environmentally superior options to LDPE in thermal packaging applications. However, this was not the case in other applications, where the outcome of comparisons between starch?CPVOH biopolymers and HDPE/EPS varied according to various factors, including the specific end-of-life scenarios and the recycled content of the petrochemical polymers. A hierarchy of critical parameters for LCA-based decision-making concerning starch?CPVOH biopolymers is suggested as a general outcome of this research.     

化学品危险性评价

介绍了化学品危险性评价的作用、目标和程序,并对评价方法的基本框架进行了描述,简要介绍了目前对化学品危险性评价工作的认识。     

炼厂氢气网络优化的计算方法

基于氢夹点理论和超结构理论,提出一套考虑燃料气价值的氢气网络优化计算方法,计算结果更加合理、经济、实用。运用此方法,不仅能定量评估某个加氢装置操作方式的合理性,而且能根据炼厂的氢气网络计算提出合理的优化运行方案。     

验证污染物减排成效方法研究

验证污染减排成效,创建污染物排放量、浓度与环境质量的相关性,分析污染物减排与环境质量之间复杂的交互关系,研究二者之间的作用响应机制;引入定义减排率与浓度降低率,创建相关性,更能真实反映减排成效。对加强环境管理、削减污染物排放、治理污染、调整产业结构、制定环境保护政策具有现实和重要的指导作用。     

粉煤灰改良重粘土地的投加量和后效试验

本文以燃煤电厂排放的粉煤灰为试验材料,研究了不同投加量对重粘土地小麦产量的影响及其后效。试验结果表明,粉煤灰改良重粘土地的效果是显著的。在一定施灰量范围内,对小麦的生长、发育及产量都有直接影响。尤以亩施5～8万斤灰增产最显著。     

固体废物堆肥处理过程中生物过滤及其臭气处理技术

臭气控制与处理是堆肥过程不可缺少的环节，国际上对其重视程度越来越高。生物过滤技术是新型的堆肥臭气处理技术，十几年来各国研究人员对其进行了大量研究。介绍了该方法的发展和现状，并对各种生物过滤器的选材、结构和特点进行了归纳。同时总结了堆肥臭气的起因以及其它各种臭气控制与处理方法。     

LNG accident dynamic simulation: Application for hazardous consequence reduction

The evaluation of exclusion (hazard) zones around the LNG stations is essential for risk assessment in LNG industry. In this study, computational fluid dynamics (CFD) simulations have been conducted for the two potential hazards, LNG flammable vapor dispersion and LNG pool fire radiation, respectively, to evaluate the exclusion zones. The spatial and temporal distribution of hazard in complex spill scenario has been taken into account in the CFD model. Experimental data from Falcon and Montoir field tests have been used to validate the simulation results. With the valid CFD model, the mitigation of the vapor dispersion with spray water curtains and the pool fire with high expansion foam were investigated. The spray water curtains were studied as a shield to prevent LNG vapor dispersing, and two types of water spray curtain, flat and cone, were analyzed to show their performance for reduction and minimization of the hazard influencing distance and area. The high expansion foam firefighting process was studied with dynamic simulation of the foam action, and the characteristics of the foam action on the reduction of LNG vaporization rate, vapor cloud and flame size as well as the thermal radiation hazard were analyzed and discussed.     

试用期可以依法延长

在上一期的文章中,笔者表达了试用期不能由单方强行延长的观点,这一立论的依据是,试用期乃是劳动合同的一部分,而劳动合同则是劳动关系当事人双方合意的产物,不能由任何一方通过单方的行为来加以改变.基于这一前提,或许有人会问,既然单方改变不合法,那么双方协商一致变更试用期总可以吧？     

选钼中间矿浓缩溢流水回收及钼精矿干燥粉尘治理

介绍了德兴铜矿对选钼中间矿浓缩溢流水循环利用所采取的措施和所取得的成果。对原钼精矿干燥除尘系统存在问题进行了整治,达到了预期效果。