Performance evaluation of reverse logistics enterprise – an agent-based simulation approach

Reverse logistics (RL) has been applied in many industries and sectors since its conception. Unlike forward logistics, retracing consumer goods from the point of consumption to the point of inception is not a well-studied process. It involves many uncertainties such as time, quality and quantity of returns. The returned products can be remanufactured, have parts harvested, or be disposed safely. It is important to implement these activities in a cost-effective manner. The aim of this research is to measure the performance of the RL enterprise with the help of an agent-based simulation model. The major entities in the RL network are considered as Agents that can act independently. There are several different agents: collector agent, sorting-cum-reuse agent, remanufacturing agent, recycler agent, supplier agent and distributor agent. The individual performances of the agents are measured and recommendations are given to improve their performance, leading to the enhancement of the total performance of the RL enterprise. The approach is applied to a case study involving cell phone remanufacturing.     

Future aspect of acquisition management in closed-loop supply chain

This paper reviews the current development and practices in closed-loop supply chain under content analysis of the published literatures. A comprehensive literature review of recent and state-of-the-art paper is vital to draw a framework and to shed light on the future direction. We have reviewed here articles on remanufacturing with special emphasis on literature related to acquisition management of returned items. For review of articles, various web-based search engine, books, journal and conference proceeding are selected and reviewed. The research papers are then analysed and categorized to construct useful foundation of past research. The review shows that current researchers are focusing on devising pricing policies to attract used products from customers. Finally, gaps in the literature are identified to suggest future research opportunities.     

Influence of crumb rubber on the geotechnical properties of clayey soil

The environmentally friendly and safe disposal of waste discarded rubber tyres are becoming a matter of serious concern across the globe because of its detrimental effect on health, environment and ecological systems. The paper aims at assessing the impact of waste rubber tyre inclusion on the geotechnical properties of clayey soil. Discarded rubber in the form of crumb rubber of size ranging between 0.8 and 2 mm varying from 0 to 10% was used in this investigation. Several tests, namely compaction, unconfined compressive strength, split tensile strength, California bearing ratio, consolidation and swelling pressure, along with microstructural studies have been carried out on different combinations of clayey soil and crumb rubber. The results of the study demonstrate that the inclusion of crumb rubber reduces the maximum dry unit weight and optimum moisture content of the clay. The addition of crumb rubber up to 5% in the clay causes an insignificant increase in the unconfined compressive strength and split tensile strength. Compared with the clayey soil, the inclusion of crumb rubber up to 5% improves the California bearing ratio of the clayey soil in unsoaked condition. It has also noticed that addition of crumb rubber helps in reducing the compression index and swelling pressure of the clayey soil.     

An analysis of end-of-life terminology in the carbon fiber reinforced plastic industry

While many studies and reviews into the practices conducted by industry and academia to recycle and remanufacture carbon fibre-reinforced plastic (CFRP) exist, to date no investigation exists which regards the correctness of the use of the terms recycling and remanufacturing. As such, this paper seeks to analyse the CFRP reuse industry’s attempt to recycle and remanufacture manufacturing waste CFRP and end-of-life (EOL) CFRP with an emphasis on the terminology used to describe these practices. Firstly, this paper presents a justification of the importance of using EOL terminology correctly; outlining the benefits and problems associated with using the correct and incorrect terminology. This paper finds that in the case of CFRP remanufacturing, terminology is being applied incorrectly and in the case of CFRP recycling, particular care should be taken when applying the term recycled to CFRP or stating that CFRP has been recycled. Further, this paper proposes new terminology (in keeping with EU directives) which could be adopted by industry and academia working in this area. This paper also finds that in the case of remanufacture, CFRP is incapable of being remanufactured.     

Issues in reverse supply chains,part I: end‐of‐life product recovery and inventory management – an overview

Recovery of used products has become a field of rapidly growing importance in reverse supply chain management. Product recovery includes collection, inspection/separation, disassembly, reconditioning/reuse, remanufacturing, and recycling. In real time situations, the collection of end‐of‐life (EoL) products from the customer and their return to the manufacturer is tedious and time consuming. Reduced product life cycles have increased the rate of product returns and disposals. Owing to shortened product economic life cycles, the recovery of value from EoL products is becoming a necessity. Companies have realised the value that they could recover by remanufacturing or recycling EoL products. Researchers have developed various models for product recovery network design, optimal inventory, production planning and control, remanufacturing, recycling, disposal, etc. The main purpose of this paper is to review the literature on EoL product recovery and inventory management issues in reverse supply chains and to outline some future directions for research on these issues.     

Social demand for multiple benefits provided by Aleppo pine forest management in Catalonia,Spain

This paper estimates the social demand for key benefits provided by Aleppo pine forests in Catalonia that can be enhanced by management. These so-called externalities are the side effects of forest management on citizens’ welfare and can be either positive or negative. The externalities addressed are: biodiversity (measured as the number of tree species), accessibility for practicing recreational activities, CO₂ sequestration and annual burned area by wildfires. By the use of a choice experiment, an economic valuation method, we estimate in a joint manner people’s preferences for these externalities and show that there is a social demand for their enhanced provision. Based on these estimates, we construct three hypothetical scenarios reflecting the range of likely outcomes of different management strategies and calculate the social demand for these scenarios. Results show that the highest gains in terms of social benefits are obtained under a scenario that minimizes the burned area (2044.23 €/ha year). Our estimates show that an increase in the investment in forest management is in line with the social demand for forest benefits and the social support that exists for a related cost increase for inhabitants.     

Commodity production as restoration driver in the Brazilian Amazon? Pasture re-agro-forestation with cocoa (<Emphasis Type="Italic">Theobroma cacao</Emphasis>) in southern Pará

The increasing demand for agricultural commodities is a major cause of tropical deforestation. However, pressure is increasing for greater sustainability of commodity value chains. This includes the demand to establish new crop plantations and pasture areas on already deforested land so that new forest clearing for agriculture is minimized. Where tree crops are planted as part of agroforestry systems on deforested land, this amounts to a form of re-agro-forestation which can generate environmental benefits in addition to crop production. Here, we discuss a case where agroforestry systems based on cocoa (Theobroma cacao) are being established on crop and pasture land in the south of Pará state, Brazilian Amazon. The adoption of cocoa by farmers and ranchers of the region is stimulated by the coincidence of (1) favorable prospects for cocoa on the national and international markets including the expectation of a global cocoa supply gap; (2) environmental policies obliging land owners to reforest excess cleared land with native trees, with agroforests based on the native cocoa tree being an economically attractive option; and (3) biophysical conditions (especially soil fertility) favorable for growing cocoa in part of the region. We show that in the state of Pará at least 1.26 million hectares of naturally high-fertility soils in deforested areas outside legally protected and indigenous lands are potentially suitable for cocoa production with low agrochemical inputs, sufficient to make a significant contribution to closing the predicted supply gap. Their actual suitability depends on their state of degradation after years of pasture use and the availability of technologies and finance to convert them into tree crop agroforests. We discuss the significant environmental benefits of pasture re-agro-forestation with cocoa-based systems, including reduced emissions of up to 135 Mg of carbon per hectare compared to the historically common scenario of planting cocoa after forest clearing. We identify important research questions related to the scaling up of this practice and the maximization of its environmental benefits. We conclude that the coincidence of the afore-mentioned factors could drive a re-agro-forestation frontier in this part of the Amazon, with potential for positive outcomes in terms of commodity production while generating social and environmental benefits.     

Effectiveness of EMS in Tunisian companies: framework and implementation process based on ISO 14001 standard

This paper reports environmental analysis results of food and tannery Tunisian companies to identify the features of environmental management system (EMS) that is implemented recently. EMS via ISO 14001 has become one of the principal tools used by companies to handle environmental aspects and impacts through their various complex activities interacted with environment. While several companies have implemented and maintained a formal EMS, it has related mainly to their benefits in short term without responding to the sustainable development recommendations and practices. This study focuses on the strong linkage between the EMS effectiveness of food–tannery Tunisian companies and sustainability. A proactive environmental management approach is proposed and adopts a qualitative and quantitative assessment for factor analysis. It provides a strategic EMS framework and principles for sustainability to evolve the future enterprises’ benefits that has a clear influence on environmental performance in long term.     

A meta‐heuristic approach for supporting adaptive disassembly sequencing using a multi‐objective concept

One of the key features of environmentally conscious manufacturing has been the efforts to promote product recycling and remanufacturing. Efficient material re‐utilisation through product disassembly to retrieve the desired parts and/or subassemblies is one rational approach. This is because it can promote the conservation of both material and energy resources whilst concurrently reducing environmental impact. However, because manufactured products may be made from many components, disassembly load becomes a critical factor that may obstruct the recovery of materials. Accordingly, it is essential to develop a practical method for deriving a disassembly plan to decrease such load, and to endow a certain value to the product at the end of its life cycle. With this understanding, the authors have developed a practical procedure to produce an adaptive disassembly strategy. The authors have applied a meta‐heuristic method known as genetic programming (GP) as a search engine to derive the adaptive disassembly sequence together with a multi‐objective optimisation method termed MOON^2R. The authors have also proposed a hierarchical sequencing method to cope with large/complex products and added several ideas to increase the applicability associated with the interests in disassembly of hazardous and/or valuable parts, and alternative disassembly actions. Through numerical experiments, the authors examined the effectiveness of the proposed approach by showing its support for relevant planning and design decisions for product recycling and remanufacturing from various viewpoints.     

The stabilization of sewage sludge by pulverized fuel ash and related materials

In Hong Kong, with the implementation of the Strategic Sewage Disposal Strategy (SSDS), there will be a substantial increase in the generation of sewage sludge. An alternative method using pulverized fuel ash (PFA) generated from a local coal fire power station and lime to stabilize the sludge for potential beneficial uses is studied. The effects of the stabilizing agents on the leaching of heavy metals and pasturing of coliform are studied. The results show that PFA together with a small percentage of lime addition has the potential to reduce heavy metal leaching and reduce the total coliform content of the stabilized sewage sludge.     

基于耦合关系的中国区域土地利用效益水平测度

新时期,土地利用的属性决定了土地利用能同时产生社会经济效益与生态环境效益,而这两种效益的交互耦合进一步决定了土地利用的整体效益。本研究建立了土地利用的社会经济效益与生态环境效益的耦合模型,设计了分别测度这两种效益的指标体系,用熵值赋权法计算了各指标的权重,进而计算了中国31个省(市、自治区)土地利用中这两种效益的系数及其耦合协调发展系数。结果显示:第一类地区是我国社会经济与生态环境均较好的上海市;第二类地区主要是社会经济发展较好但生态环境建设相对滞后的地区;第三类是生态环境较好但社会经济发展相对滞后的地区;第四类是社会经济发展相对滞后但生态环境建设更为落后的地区;第五类是生态环境建设滞后但社会经济发展更为落后的地区。最后,对每一个类型的成因和未来发展思路作了说明,在此基础上,又说明了中国土地利用的整体效益仍较为有限、整体效益表现出较为明显的区域分布特征、社会经济与生态环境的协调发展已成为提高我国土地利用效益的现实选择等基本政策含义。     

预期收益、可行能力对农户生态耕种采纳意愿的影响及其代际差异

利用江西省2 068份调研数据,借鉴目标设置理论,实证分析预期收益、可行能力对农户生态耕种采纳意愿的主效应和调节效应及其代际差异的影响。结果显示:(1)预期收益对农户生态耕种采纳意愿产生显著影响,高预期收益对农户生态耕种采纳意愿具有正向作用,而中等预期、低预期收益对农户生态耕种采纳意愿具有负向作用;而且预期收益对农户生态耕种采纳意愿的作用存在代际差异。(2)可行能力的提高对农户生态耕种采纳意愿具有正向影响,而且在其预期收益与生态耕种采纳意愿的关系中具有调节作用。因此,应鼓励农户进行生态耕种,并通过示范作用,强化对预期收益的认可;加大生态耕种的基本知识宣传和相关技能培训提升自身的可行能力;生态耕种的激励政策应体现差别化来适应代际差异需求。     

可持续能源转型:模型构建与分析

为研究可持续能源系统转型路径,以转型理论为概念框架,从宏观、中观和微观多层次对能源系统进行分析,建立了基于代理的系统动力学转型模型。模型选取当前能源消费结构中占较大比重的煤炭、石油、天然气、风能、水电、光伏和核能作为复杂代理,选取消费者作为简单代理,根据中国能源数据对其进行参数化,并模拟运行了能源系统从2016—2050年间各种类型能源消费比重变动的情形。研究结果显示:①外部景观信号的输入对于能源系统的可持续转型有着至关重要的作用。随着景观信号的输入,各类能源的相对比重发生复杂的相互作用,景观信号持续时间越长、强度越大,向可持续能源系统转型的速度越快、规模越大。②到2050年,可持续能源将占一次能源消费比重的60%左右,实现能源系统的可持续转型,其中,水电将在能源系统的可持续化转型中发挥重要的作用。③2030年以前,石油和天然气将是能源系统中煤炭消费比重下降的主要替代品,因为它们的应用技术已经发展成熟,而且它们更适应当前的基础设施,从短期来看相比可持续能源石油和天然气更有优势,在这种情形下,仍然需要继续支持可持续能源的发展,否则能源系统的可持续转型将不会发生。该研究主要探索通过当前能源系统的景观压力强度以及转型的进度,来量化未来需要输入的景观压力强度;通过模拟转型发生的具体情景,对转型的进展进行更清楚的界定,借此来评估二氧化碳的排放路径;模拟模型也可以评估各类能源在不同时间点上的各种可能性,以及探索各类可持续能源的发展潜力。     

Costs and benefits of adapting spatial planning to climate change: lessons learned from a large-scale urban development project in the Netherlands

Climate change increases the vulnerability of low-lying coastal areas. Careful spatial planning can reduce this vulnerability, provided that decision-makers have insight into the costs and benefits of adaptation options. This paper addresses the question which adaptation options are suitable, from an economic perspective, to adapt spatial planning to climate change at a regional scale. We apply social cost–benefit analysis to assess the net benefits of adaptation options that deal with the impacts of climate change-induced extreme events. From the methods applied and results obtained, we also aim at learning lessons for assessing climate adaptation options. The case study area, the Zuidplaspolder, is a large-scale urban development project in the Netherlands. The costs as well as the primary and secondary benefits of adaptation options relating to spatial planning (e.g. flood-proof housing and adjusted infrastructure) are identified and where possible quantified. Our results show that three adaptation options are not efficient investments, as the investment costs exceed the benefits of avoided damages. When we focus on ‘climate proofing’ the total area of the Zuidplaspolder, when the costs and benefits of all the presented adaptation options are considered together, the total package has a positive net present value. The study shows that it is possible to anticipate climate change impacts and assess the costs and benefits of adjusting spatial planning. We have learned that scenario studies provide a useful tool but that decision-making under climate change uncertainty also requires insight into the probabilities of occurrence of weather extremes in the future.     

2003～2011年四川省各市(州)农业水足迹时空变化与驱动力研究

运用水足迹理论和计算方法,系统分析了四川省各市(州)2003~2011年农业水足迹的时空动态变化趋势与农业水资源利用效益,并采用灰色关联度法分析其驱动力因素。研究结果表明:(1)四川省各市(州)农业水足迹和人均农业水足迹均呈增加的趋势变化,成都市、南充市、达州市农业水足迹较大,2011年农业水足迹分别达82.44×108,45.56×108,41.02×108 m3。人均农业水足迹各市(州)差距不大,其中成都市和攀枝花市略高。(2)农业水资源利用效益方面显示:四川省各市(州)农业水足迹净贸易量均为正值,属于农业水资源净输出地。2006、2009、2010和2011年农业水资源匮乏度较高,成都市水资源紧缺度最高,2005~2010年均在200%以上。(3)驱动因素方面显示:耕地复种指数和人口总数是农业水足迹变化的关键驱动因素,关联度分别是0.643 3和0.632 5。建议提高水资源利用效益,适当控制高耗水农产品生产规模,合理配置水资源,实现空间和季节用水的协调性。     

Application of active disassembly to extend profitable remanufacturing in small electrical and electronic products

Alternative production approaches are required because of conventional manufacturing's adverse environmental impacts. Remanufacturing returns used products to at least original performance specification from customers' perspectives and gives the resultant products warranties at least equal to that of new equivalents. Remanufacturing is relatively novel in research terms compared to conventional manufacture and recycling but often is more profitable than both. It would help manufacturers address competitive, environmental and legislative pressures by enabling them to meet pressing waste legislation while producing high-quality, lower cost products with less environmentally damaging end-of-life (EoL) and manufacturing modes. Remanufacturing is highly profitable in large, complex mechanical and electromechanical products but with conventional manufacturing and design modes not so in smaller products; particularly fast moving ones. However, effective waste management is urgently required for such products because waste electrical and electronic equipment constitutes the fastest growing EU waste stream and a large percentage of products being produced by major developing economies such as China are of this type. Active disassembly (AD) enables product non-destructive, self-disassembly at EoL and was invented to facilitate a step-change improvement in recycling. This research investigated the use of AD to extend profitable remanufacturing into small EoL electrical and electronic products.     

基于适宜性评价的中心城区建设用地布局——以杭州市为例

中心城区建设用地布局优化有助于发挥建设用地的最大效益,关系整个区域土地资源的合理利用和社会经济的可持续发展。采用主成分分析方法从栅格尺度评价杭州市中心城区建设用地适宜性,同时针对中心城区的特点侧重于经济适宜性,并结合GIS技术,实现基于建设用地适宜性评价的中心城区建设用地布局方案。结果表明:侧重经济适宜性的建设用地适宜性评价结果作为杭州市中心城区建设用地布局的决策依据是科学合理的,有助于确定未来城市发展的优势区位,并且布局方案相对紧凑,能有效引导城市紧凑化发展,抑制城市沿主干道蔓延式开发。另外,基于适宜性评价的中心城区建设用地布局是一种自上而下的布局方式,较难体现邻域动态影响、局部规则的交互作用以及不同主体城市开发决策行为所导致的空间格局,可能导致布局结果与城市实际发展情况的偏离,对此仍有待进一步深入研究。     

Eco-efficiency in Portuguese companies of marble sector

The activities developed within an eco-efficiency project in mineral industries located in the largest area for marble extraction in Portugal, in Alentejo region, in the Estremoz – Borba and Vila Viçosa anticline are presented in this paper. The project was designed to apply the sustainability concept in seven companies of marble extraction and transformation. The adopted strategy used new cleaner production models together with sustainable value (SV) improvement, leading to the rationalization of the industrial process, the involvement of economic agents and the orientation of the management of production processes towards eco-efficiency. The challenge was to have the mineral industry managing efficiently the resources on which the business depends, according to sustainability principles. Different opportunities for improvement, related to the minimization of materials, water and energy use, were identified in the companies. Some proposals mainly related to social improvement and small and medium-sized enterprise competitiveness benefits were also selected and discussed. This approach allows the integration of sustainability at company's and region's levels by combining in the entrepreneurial activity the creation of wealth together with the environment protection and the achieving of social benefits. Highlights: The involvement of different stakeholders in the project (Eco-efficiency in Portuguese companies of marble sector) was positive in the discussion and search of solutions for companies. It is possible to involve marble extraction and processing companies in eco-efficiency improvement towards sustainability. Companies from the marble sector improved environmental and social performance and reduced the costs of their production processes by applying SV methodology.     

Climate change and village adaptation impact on reliability of irrigation wells in China

This paper builds a water supply reliability econometric model to analyze climate changes and adaptation impact factors on water supply reliability of irrigation wells by using 100 villages’ three-year (2010–2012) field survey data of five middle and eastern provinces of China. The results show that long-run climate change factors, adaptation measures, village-level organizations of irrigation management, as well as extreme climate factors affect the water supply reliability of irrigation wells significantly. Meanwhile, there are significant differences impacting different crops and provinces. This paper suggests that agriculture meteorological disaster monitoring and warning systems should be strengthened by increasing irrigation facilities construction and maintenance, promoting reform of agricultural irrigation water management system, and developing various forms of peasant cooperation organization in order to improve agricultural production capacity to adapt to climate change.     

Optimal acquisition price management in a remanufacturing system

Return items received from end customers for remanufacturing is uncertain in nature. In this paper, we considered that return demand function is uncertain and sensitive to the acquisition price and the availability of used products in the market. A mathematical model was developed to investigate the impact of the availability of return items in the market on acquisition price management. Here, three different methods of collection of return items from the market are considered: direct method, indirect method and coordinated method. A numerical study was conducted to illustrate the mathematical model, and an extensive sensitivity analysis was carried out for the three different methods of collection to examine the impact of market size and the available dependency factor on acquisition price and the channel profit. The results show that the total channel profit increases when the acquisition price increases for the direct method of collection. Furthermore, the results reveal that the total channel profit increases when the market size increases for the coordinated method of collection compared with the other two methods of collection.