The impact of government subsidy and tax policy on the competitive decision-making of remanufacturing supply chains

In this paper, we consider a two-period competition model of a remanufacturing supply chain consisting of three members: a new product manufacturer, a recycler and a remanufacturer. The manufacturer supplies new products in the first period and the remanufacturer participates in the competition in the second period. We consider three scenarios in the second period: (1) there is no government subsidy in the competition; (2) there is only government subsidy in the competition; (3) there are both government subsidy and tax in the competition. First, we give the optimal decision-making of the manufacturer, the remanufacturer and the government in the three scenarios; second, we analyse changes in the decision-making of the manufacturer and remanufacturer in the three scenarios and compare their results. We analyse the effects of government subsidy and tax and their asymmetric use on manufacturers’ and remanufacturers’ decision-making variables and competitive performance. We also take consumer awareness of environmental protection into account and examine its impact on subjects’ decisions. Lastly, we operate a numerical example to show the results.     

Management of two competitive closed-loop supply chains

The two competitive closed-loop supply chains under our study include three members: two manufacturers and one retailer. In this paper, we focus on the management of the wholesale prices, the retail prices and the collecting prices for the two competitive closed-loop supply chains. On the assumption that the return rate of the used-products is an increasing function of the collecting price, we obtain the optimal wholesale prices, the optimal retail prices and the optimal collecting prices based on the following models: Model MMC (two manufacturers for collecting), Model MRC (manufacturer one and retailer for collecting) and Model RRC (retailer for collecting). Furthermore, by comparing the optimal results, we find that the retailer for collecting is the best channel for the two competitive closed-loop supply chains if the two manufacturers would like to transfer all of their cost savings from remanufacturing to the retailer. At the end, we illustrate a numerical example to analyse the impacts of the market share ratio and the substitute ratio of the two products on the optimal results.     

The research of market structures for remanufactured products

The rapid development of technology has made it easier to distribute products directly, and many enterprises excel at executing a multi-channel strategy to distribute products. The introduction of direct channel adds a new competition dimension to the enterprises. This paper considers three market channel structures: R-Channel, D-Channel and H-Channel. In R-Channel, both new products and remanufactured products are sold through a retailer. In D-Channel, new products are sold through retailers and remanufactured products are sold directly to consumers. In H-Channel, new products are sold through retailers, while remanufactured products through dual channel. Using the game theory, we obtain and analyse the equilibrium prices, market demands and the profits gain under these three settings. At the same time, the influence of consumers’ willingness to pay on the environment performance is researched. Our results show that the manufacturer prefers H-Channel. By introducing the direct channel the manufacturer is always economically better off, but it is not for the retailer. The numerical simulation also confirms the theoretical analysis and shows that H-Channel has advantages of economic benefit and environmental performance. It is feasible for practical application.     

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.     

基于资源-技术-环境的高技术城市矿产战略性筛选

城市矿产中蕴含大量的高技术矿产,它们是战略性新兴产业发展的关键原材料。本文从中国国情出发,界定了涵盖新能源技术、通讯设备、交通工具、电池、电器电子产品等5大类共计27种高技术城市矿产,从资源、技术、环境三个维度设计了11项指标,对高技术城市矿产进行战略性筛选;并通过半定量化不确定性分析方法确定研究结果的可靠性。结果显示:(1)从资源-技术两维度看,电器电子产品用电池资源指数高,且技术相对成熟;动力汽车电池资源指数值略低,但未来开发潜力大。(2)从资源-环境两维度看,电池是拆解处置重点。(3)从资源-技术-环境三维度来看,高技术城市矿产可以分为四个梯队:高资源指数、高技术指数、高环境指数的"三高"梯队,包括EEE用镍氢电池、EEE用镍镉电池、EEE用锂离子电池;中高资源指数、中高技术指数、中高环境指数的"三中高"梯队,包括手机和动力汽车电池;低资源指数、低技术指数、中高环境指数的"二低一中高"梯队,包括风涡轮机、荧光灯、动力汽车永磁电机和电话机;资源指数、技术指数、环境指数都相对较低的"三低"梯队,包括电器电子产品和光伏电板。此外,随着时间的推移,筛选结果会发生动态变化,因此高技术城市矿产的战略性筛选是一个持续动态的评估过程,需要建立与之相适应的"开发一批、储备一批、谋划一批"的动态管理系统。基于研究结论,本文从高技术城市矿产的基础数据库建立、重点开发目录制定与调整、在线回收与交易平台构建、拆解技术储备以及可持续供应体系建立等方面提出了建议。     

A study of the atmospheric dispersion of a high release of krypton-85 above a complex coastal terrain, comparison with the predictions of Gaussian models (Briggs, Doury, ADMS4)

Atmospheric releases of krypton-85, from the nuclear fuel reprocessing plant at the AREVA NC facility at La Hague (France), were used to test Gaussian models of dispersion. In 2001-2002, the French Institute for Radiological Protection and Nuclear Safety (IRSN) studied the atmospheric dispersion of 15 releases, using krypton-85 as a tracer for plumes emitted from two 100-m-high stacks. Krypton-85 is a chemically inert radionuclide. Krypton-85 air concentration measurements were performed on the ground in the downwind direction, at distances between 0.36 and 3.3 km from the release, by neutral or slightly unstable atmospheric conditions. The standard deviation for the horizontal dispersion of the plume and the Atmospheric Transfer Coefficient (ATC) were determined from these measurements. The experimental results were compared with calculations using first generation (Doury, Briggs) and second generation (ADMS 4.0) Gaussian models. The ADMS 4.0 model was used in two configurations; one takes account of the effect of the built-up area, and the other the effect of the roughness of the surface on the plume dispersion. Only the Briggs model correctly reproduced the measured values for the width of the plume, whereas the ADMS 4.0 model overestimated it and the Doury model underestimated it. The agreement of the models with measured values of the ATC varied according to distance from the release point. For distances less than 2 km from the release point, the ADMS 4.0 model achieved the best agreement between model and measurement; beyond this distance, the best agreement was achieved by the Briggs and Doury models.     

Opportunities for redistributed manufacturing and digital intelligence as enablers of a circular economy

The linear production of consumer goods is characterised by mass manufacture by multinational enterprises and globally dispersed supply chains. The current centralised model has created a distance between the manufacturer and end user, limiting the opportunity for intelligent circular approaches for production and consumption. Through a mixed method approach, opportunities of circularity are explored for the consumer goods sector. The study presents four lenses to analyse three enterprises through a multi-case study approach to explore the potential of digital intelligence and redistributed manufacturing (RDM) as enablers of circular business models. In addition, the study examines whether Discrete Event Simulation can be used to evaluate the circular scenarios identified through quantifying flows of material that determine traditional economic value (cost/tonne). The mixed method approach demonstrates that, a qualitative systemic analysis can reveal opportunities for circularity, gained through implementing ‘digital intelligence’ and distributed models of production and consumption. Furthermore, simulations can provide a quantified evaluation on the effects of introducing circular activities across a supply chain.     

A biophysically anchored production function

The first part presents a conceptual model of the economic system in its ecological and social context. It is developed via an integration of basic concepts in physical resource theory, animal and human physiology, economic theory and systems ecology. The capacity of the model to support analysis of such complex systems where life is a key system characteristic is high. The conceptual model shows the dependency of the human economy on support by non-renewable and renewable resources from Nature (i.e. ecological source restrictions), as well as the capacity of ecosystems to assimilate wastes (ecological sink restrictions). The analysis focuses general principles; thus, the high level of abstraction results in an apparent simplicity. In the second part, we integrate traditional economic production functions and the conceptual model, which results in the formulation of a biophysically anchored production function (BAPF). The BAPF by itself, and through the system of ecological economic accounts that can be derived from it, represent a toolbox that supports the operationalisation of a sustainable development from micro to macro level. It is coherent with Impredicative Loop Analysis, existing management systems within agricultural sciences, OECD’s principles for sustainable development and the approach of Millennium Ecosystem Assessment. Compared to analytical approaches used in the formulation of sustainability policies in the private and public sphere, based on conceptual models ignoring the complexity when life (bios) is a defining system characteristic, its relevance for the operationalisation of sustainable development approaches infinity. The third part presents results from statistical analysis of relations between gross domestic product and energy supply and some emissions, respectively, for different nations and time periods, delivering values on levels and trends for parameters in the BAPF as well as a first test of the relevance of the BAPF proposed. The paper is ended by a theoretical analysis of the costs of provoking an economic system working under ecological source and sink restrictions to follow exponential growth: The need to decouple economic growth from natural resource use and emissions is highlighted. Otherwise, the erosion of the ecological foundation of the economy with regard to source as well as sink aspects will be a function of exponential growth.     

Sustainable tyre remanufacturing: an agent-based simulation modelling approach

This paper addresses sustainable benefits of remanufacturing tyres. An agent-based simulation approach is used to tackle this research problem by identifying different agents such as tyre, collector, recycler and remanufacturer. Details related to every agent are provided to show the decisions taken by these agents and the impact that may have on tyres' remanufacturing industry. Relying on input data from published reports and papers by academics and professional organisations, experiments are conducted on various scenarios to show the benefits of increasing the retread percentage of passenger car tyres. The results show that retreaded tyre can capture almost 25% of replacement (sales) market, resulting in significant reduction in scrap tyres and raw material consumption. This percentage can further be increased by increasing the number of retreads per used tyre and the life of tread rubber. The output results help in finding the profit break‐even point at various levels of retread. The results also show other decision-making implications, particularly related to rejection rate and ways to reduce it.     

Evaluating efforts to build sustainable WEEE reverse logistics network design: comparison of regulatory and non-regulatory approaches

Many developing countries such as Turkey are still making an effort on building an infrastructure for waste of electrical and electronic equipment (WEEE) reverse logistic network design (RLND) processes. It is obvious that policies/laws/regulations related to WEEE management provide a sustainable framework for implementation in the RLND. The question is here: Does the implementation of WEEE directives make sense in terms of reducing the total cost of the network in the long term? This study aims to compare regulatory and non-regulatory situations of WEEE RLND in developing countries by formulating two models named as ‘regulatory’ and ‘non-regulatory’. Model 1 is considered as sustainable with economic, environmental and social goals, and the quotas imposed by the environmental directive are taken into consideration as the data of product return amount. In Model 2, only economic goal is considered, and product return amount is forecasted using Artificial Neural Network (ANN). A case study is conducted in a recycling company in order to evaluate performance of the proposed models. This study contributes to the relevant literature by (1) comparing the regulatory and non-regulatory situations RL models explicitly and (2) proposing ANN model to forecast EEE product return or WEEE quantity for non-regulatory situation.     

Assessment of state-of-the-art models for predicting the remobilisation of radionuclides following the flooding of heavily contaminated areas: the case of Pripyat River floodplain

The performances of models are assessed to predict the wash-off of radionuclides from contaminated flooded areas. This process should be accounted for in the proper management of the aftermath of a nuclear accident. The contamination of the Pripyat River water following the inundation of a floodplain heavily contaminated by (90)Sr and (137)Cs of Chernobyl origin is used as the basis for modelling. The available experimental evidence demonstrated that remobilisation of radiostrontium is an important process implying a significant secondary radioactive load of water flowing over the contaminated floodplain. On the contrary, there is no empirical evidence of a similar behaviour for radiocaesium. In general, state-of-the-art models properly predicted the remobilisation of strontium, whereas they significantly overestimated radiocaesium concentrations in water. The necessary model improvements for a more accurate prediction of radiocaesium contamination levels include a reassessment of the values of the model parameters controlling the remobilisation process.     

Probabilistic biokinetic modelling of radiocaesium uptake in Arctic seal species: verification of modelled data with empirical observations

The necessity to provide information about radionuclide concentrations in Arctic marine species has been heightened in recent years due to a number of accidents in Arctic regions involving nuclear vessels and the presence of a large number of potential radioactive contamination sources. The provision for such information is largely dependent on the use of radionuclide uptake and transfer models. The uptake of radionuclides in Arctic seal species in this study has been modelled using a probabilistic biokinetic approach. In this paper, model results are compared with empirical data from relevant samples taken within the Arctic region. Results indicate that the model performs well when estimating concentrations of (137)Cs in two seal species for both median values and reproduction of the distribution of data values, but not as well for a third seal species. Likely factors affecting the results are the probability density functions used for the input parameters.     

长江中游城市群生态承载力差异的比较研究

基于生态足迹模型方法，对2008～2017年长江中游城市群生态承载力的差异性进行了比较研究，研究发现：（1）长江中游城市群整体及湖北、湖南、江西省域人均生态足迹呈现“倒U型”特征，在3个省份中，湖北省域人均生态足迹最高，湖南、江西较接近；（2）长江中游城市群整体及湖北省域人均生态承载力呈现逐年上升态势，湖南省域、江西省域总体人均生态承载力呈现微弱下降态势，且江西省域最高、湖北省域次之、湖南省域最低，社会经济发展水平越高的城市，人均生态承载力就越小，生物资源项目比重较高；（3）各省域生态赤字水平均呈现逐渐扩大的趋势，湖北省域最高、湖南省域次之，江西省域最低，且第一梯队的城市主要分布在湖北省域，第四梯队的城市主要分布在湖南省域和江西省域；（4）各省域生态压力指数发展趋势呈现明显的“倒U型”特征，湖北省域最大，湖南省域次之，江西省域最小；（5）各省域生态压力指数发展趋势呈现明显的“U型”特征，江西省域最大，湖南省域次之，湖北省域最小。鉴于此，本文从优化能源消费结构、集约化土地使用结构、差别化使用土地等方面提出相关的对策建议。     

Who is importing forest products from Africa to China? An analysis of implications for initiatives to enhance legality and sustainability

Global forest product value chains are increasingly subject to regulatory requirements, such as legality and sustainability certification. For African forest products, a shift in the export destinations of forest products towards China, the leading timber product manufacturer, has raised concerns that social and environmental product and process standards are declining. Aggregate drivers of this shift have been documented, yet there has been little enterprise-level analysis of Chinese actors in African timber imports based in China. This paper provides an initial analysis, highlighting implications for existing and emerging regulatory initiatives. Data show that although an increasing number of Chinese private enterprises is engaged in African timber imports, import volumes remain concentrated among a small number of geographically clustered private and state-owned firms. Government-led schemes are beginning to address timber legality concerns. But given China’s growing domestic market for finished wood products, sustainability certification requirements driven by the US and EU will not be sufficient to ensure improved sourcing by Chinese firms.     

Soil-plant-animal transfer models to improve soil protection guidelines: a case study from Portugal

Food chain models are essential tools to assess risks of soil contamination in view of product quality including fodder crops and animal products. Here we link soil to plant transfer (SPT) models for potentially toxic elements (PTEs) including As, Ba, Cd, Co, Cu, Hg, Ni, Pb, Sb, U and Zn with models describing accumulation in animal organs. Current EU standards for food products and acceptable daily intake levels (ADI) for humans were used as critical limits. The combined model is used to assess the impact of soil contamination on animal health, product quality and human health using data from 100 arable fields. Results indicate that 42 existing arable fields near industrial and mining sites are unsuitable for animal grazing in view of food safety due to elevated intake of Cd, Cu, Hg and Pb by cows and sheep. At 10 sites daily intake levels of As by cows exceeded threshold concentrations regarding the quality of animal products.The food chain model also was used inversely to derive soil threshold concentrations in view of EU fodder standards. Calculated threshold levels in soil for As, Cd, Cu, Pb, Hg and Zn appear to be in line with those proposed or used in other EU countries. As such the approach applied here can form a conceptual basis for a more harmonized risk assessment strategy regarding the protection of animal and human health.     

The forecasting of municipal waste generation using artificial neural networks and sustainability indicators

The feasibility of modeling municipal waste generation (MWG) for countries at different levels of development using artificial neural networks (ANN) and selected generic indicators of sustainability was investigated. The main goals of this research were to develop ANN-based models for predicting MWG, to overcome the problem of incomplete MWG data, which is notable in developing countries, and to provide a new method for the planning of municipal solid waste management systems as well as for the simulation of various other scenarios. Data from 26 European countries was used in this study as training, test and validation datasets for the developing of ANN models. Since this kind of modeling is particularly important for developing countries where MWG data is missing or incomplete, emphasis was placed on modeling of MWG for Bulgaria and Serbia. Based on a comparison of actual MWG data with predictions given by the model, we show that ANNs can be applied successfully to modeling and forecasting MWG on a national scale. Moreover, the scope for possible application of the model is broad, since it uses generic indicators of sustainability such as gross domestic product, domestic material consumption and resource productivity, and performs well for countries with highly diversified levels of economic development, industrial structure, productivity and output.     

Measurement of Fruit and Vegetable Losses in Brazil: A Case Study

This research conducted on municipal solid waste management for the first time quantified food spoilage as being 8.8% weight of all officially collected household garbage in the Brazilian city under study. The unexpected size of this waste fraction gave rise to work on the causes of waste and on its distribution over the product life cycle specific to fruit and vegetables. Waste was defined as being the combination of losses and scraps. Administrative shortcomings were identified as basic reasons for waste. At the producer and consumer ends of the cycle, negligence was shown to be the single most important problem. Fruit and vegetables deteriorate during the operations of handling, transport, packaging, storage, selling and consumption. The study detailed the occurrence of waste at all of these stages. In the medium-size Brazilian city, the total waste of fruit and vegetables was shown to amount to 16.6% weight in the marketing stage of the life cycle. At the consumer level, it was measured as 3.4% weight of all household garbage. Specific reasons for this waste were identified at the levels of producer, wholesaler and retailer. Short-term remedies were pointed out that invariably corrected deficient management procedures. It was shown that very simple administrative measures can significantly reduce the spoilage of fruit and vegetables. Long-term strategies involve the creation of sample cases for administration of the fruit and vegetables life cycle at all stages.     

Comparing environmental product footprint for electronic and electric equipment: a multi-criteria approach

Electronic and electric devices are now applied in most human activities: their diffusion is increasing worldwide; furthermore, most of them are characterized by a high replacement rate due to technological obsolescence. Consequently, environmental problems due to their diffusion are increasing; several aspects are involved from the energy consumption derived from their manufacturing processes and their use phases to their end-of-life (EOL) management. Such legislative (e.g. the European Energy Efficiency directive for household appliances) or voluntary interventions (e.g. based on the ISO standards) have been introduced for such devices: the aim is to incorporate environmental considerations in product design and manufacturing in order to benefit the environment. Some attempts are focusing on defining standardized models for the overall lifecycle including waste management. The aim of this paper is to introduce a reference model for comparing environmental product footprint of electrical and electronic equipment (EEE). All life cycles of EEE will be evaluated: a specific focus is on the EOL management process as their waste management represents a complex problem for developed and developing countries. A multi-criteria decision-making model will be developed based on the well-known analytical hierarchy process (AHP) method: differently from traditional AHP applications, an absolute model has been proposed in order to compare EEE effectively from an environmental point of view. A case study validation regarding large household appliances is proposed.     

Integrating Concepts and Models from Development Econoimcs with Land use Change in the Tropics

In this paper I undertake a preliminary assessment for the tropics of the relation of economic development, meaning in general increases in economic activity as measured by e.g. GDP, and its normal biophysical corollaries of increased resource use and land use change. I also examine each in relation to the intellectual concepts that underlie and guide what is commonly called economic development. Because most of the development literature is derived from economics or other social sciences, and focuses almost entirely on lifting people’s standards of living as measured in monetary units, very little examines the per unit biophysical requirements of that development, including energy or other resource use requirements, land use change or other environmental consequences of development plans. In addition there seems to be insufficient connection between those who create economic development plans and those who undertake empirical biophysical assessments to determine whether the development plan has worked or can possibly work. The problem is deeper: there exists a series of models used in the development literature that have been used to encourage and guide development. These models have received very little scrutiny as to either their efficacy or their societal or environmental impacts until quite recently. When this has been done the models have been shown to fail miserably. It is time to develop a new model of development that synthesizes conventional economic, biophysical economic and social aspects, and that is based on the scientific method rather than on perceived wisdom. This model must also take into account population growth, issues of who wins and who looses from economic development, and the implications of the incipient peak in global oil production.     

Comparison between the predictions of a Gaussian plume model and a Lagrangian particle dispersion model for annual average calculations of long-range dispersion of radionuclides

This study attempts to validate the applicability of a simple Gaussian dispersion model for predicting long-range dispersion of continuous releases from an industrial site, by comparison with a Lagrangian particle dispersion model. The United Kingdom Meteorological Office model NAME has been used to predict annual average concentrations of radionuclides over Western Europe, resulting from discharges from the British Nuclear Fuels (BNFL) site at Sellafield, UK. The results are compared here to calculations performed using a conventional Gaussian type of dispersion model, PLUME. The results of the Gaussian model were compared at 14 locations within Western Europe at long range (up to 1700 km). The differences in predictions between the models were explained readily by differences in the way dispersion and deposition processes are represented in the two models. However, differences are generally small compared to the expected precision of the models. The implementation of environmental processes in NAME is more complete and realistic than in PLUME, and as such the results from this model may be considered more realistic. However, given that PLUME is much simpler to use, and appears to over-estimate, rather than under-estimate, environmental concentrations, its use for radiological assessments appears appropriate.