Quantitative sustainability assessment of remanufacturing waste reinforcing steel

Construction is a major contributor to the solid waste stream globally and various recycling strategies are being evaluated to recover valuable resources. As a novel strategy, remanufacturing waste reinforcing steel bar (rebar) pieces from concrete waste to produce nails was applied on an industrial scale to prove the technical feasibility, where a group of alternatives were developed based on commercially available industrial machinery. The calculated economic and environmental feasibility values are sufficiently high for industrial application, and the most appropriate remanufacturing technological alternative was identified. The sustainability equation was solved to find the social feasibility and overall remanufacturing sustainability index. Rebar waste remanufacturing has a high triple-bottom-line sustainability index of 0.885. Based on the proposed process, small remanufacturing companies can be developed, thereby aiding employment and human development by earning profit of 1904–8880 USD/day. The findings of this study are beneficial to decision makers in government and industry and are globally relevant because concrete waste is ubiquitous worldwide.     

Analytical Solutions to Trade‐Offs between Size of Protected Areas and Land‐Use Intensity

Abstract: Land‐use change is affecting Earth's capacity to support both wild species and a growing human population. The question is how best to manage landscapes for both species conservation and economic output. If large areas are protected to conserve species richness, then the unprotected areas must be used more intensively. Likewise, low‐intensity use leaves less area protected but may allow wild species to persist in areas that are used for market purposes. This dilemma is present in policy debates on agriculture, housing, and forestry. Our goal was to develop a theoretical model to evaluate which land‐use strategy maximizes economic output while maintaining species richness. Our theoretical model extends previous analytical models by allowing land‐use intensity on unprotected land to influence species richness in protected areas. We devised general models in which species richness (with modified species‐area curves) and economic output (a Cobb–Douglas production function) are a function of land‐use intensity and the proportion of land protected. Economic output increased as land‐use intensity and extent increased, and species richness responded to increased intensity either negatively or following the intermediate disturbance hypothesis. We solved the model analytically to identify the combination of land‐use intensity and protected area that provided the maximum amount of economic output, given a target level of species richness. The land‐use strategy that maximized economic output while maintaining species richness depended jointly on the response of species richness to land‐use intensity and protection and the effect of land use outside protected areas on species richness within protected areas. Regardless of the land‐use strategy, species richness tended to respond to changing land‐use intensity and extent in a highly nonlinear fashion.     

An Experiment in Making Water Affordable: Philadelphia’s Tiered Assistance Program (TAP)

The ability to pay for water and wastewater services is a growing issue in the developed world. To this point in time, utilities have helped customers grappling with affordability issues using different types of customer assistance programs (CAPs). Income‐based billing approaches differ from CAPs in that bills are structured so as to be affordable for customers at the outset. Recently, the City of Philadelphia implemented an innovative program to work towards resolving the affordability problem in their city using income‐based billing. This tiered assistance program or TAP structures bills for water, wastewater, and stormwater services to program enrollees’ income. Given the innovative nature of the program, this paper describes the rollout of TAP and assesses the impact of the program on customers and utility revenues. The paper closes with a critical assessment of TAP and considerations for utilities evaluating the implementation of similar programs.     

Controversial sectors in banks’ sustainability reporting

Albeit indirectly, through its lending and investing, the financial sector can contribute substantially to achieve sustainable development. One of such practices concerns investment on or financing of entities that deal with environmentally or socially sensitive transactions (gambling, tobacco, alcohol, arms, etc.). Although there is a wealth of literature on banks’ CSR and its reporting, one can count on the fingers of one hand the studies mentioning explicitly these issue. What is more, this CSR practice gets treated only cursorily in these few studies. This study focuses on the communication of information on investment and financing of firms from controversial sectors in banks’ sustainability reports. We begin by examining whether financial institutions in our sample report having such policies or not. Then, we investigate what kind of policies are reported. In addition, this study seeks to capture the influence of national culture and firm-specific characteristics (type of property, listing status and multinationality) on the reporting of such issues. Ordinal regression analysis is used to analyse the relation of these factors with such reporting. Our findings suggest that the disclosure of information on policies regarding investment on and financing of firms from controversial sectors is not widespread, and the organizations reporting policies of total exclusion of some sectors or projects on ethical grounds are few. This study may encourage more detailed analyses of the type of CSR policies examined and of their impacts. It also may be of utility to banks by raising awareness about the need to consider these issues.     

Sustainability in water resources management: changes in meaning and perception

The meaning of sustainability in water resources management has changed through the time. Initially, meeting water demand was the dominant concern. While later quality issues became more important followed by wider water reuse, today sustainability must include a whole range of aspects (e.g., energy, pollution, persistent chemicals) on various spatial and time scales. New approaches to define sustainability metrics are needed that include three essential elements: the sphere of sustainability, its time horizon and its metric.     

Closed-loop supply chain system with energy,transportation and waste disposal costs

Energy usage and consumption play important and strategic roles in modern manufacturing, inventory and logistics systems. The literature on inventory models for closed-loop supply chains reveals that, for no clear reasons, energy costs were ignored along with transportation and disposal costs. This paper introduces a closed-loop supply chain model that considers the economic value and energy content of products. It also offers a novel framework for studying lot-sizing policies of production processes in that context. Thus, a mathematical model for a closed-loop supply chain system with energy, transportation and disposal costs is developed. Numerical examples are provided with their results discussed. The developed model was also compared to that of Richter (1996) to stress the importance of accounting for the three noted costs. The numerical results emphasise that accounting for energy, transportation and disposal costs in supply chain modelling increases the sustainability of a production-inventory system due to the strong interdependence of the three costs on one hand, and their relationship to the environment on the other hand.     

Production of phosphorus-containing oleochemicals through an epoxide route

Phosphorus-containing moieties can be added to the ninth and/or tenth positions of a fatty chain of a methyl ester utilising an epoxide route. In this route, methyl oleate is epoxidised, and then ring opened using dibutyl phosphate to yield – among others – a dioxaphospholane-containing derivative of methyl octadecanoate. Progress of the reaction was determined by gas chromatography-mass spectrometry and compounds were identified by nuclear magnetic resonance spectroscopy. Addition of a titanium and zirconium oxide catalyst increased the yield of dioxaphospholane from 27%, observed without catalyst, to 37%. A similar reaction using bis-2-ethylhexyl phosphate gave 22% and 29% yield. However, an aryl phosphate, diphenyl phosphate, was not active in these reactions. The aliphatic compounds obtained are likely to be useful sulphur and metal-free extreme pressure lubricant additives which are highly compatible with vegetable oil-based lubricants.     

The Ecology of Empire: Wal-Mart's Rhetoric of Environmental Stewardship and the Constitutive Power of the Multitude

This essay provides a critical account of Wal-Mart's rhetoric of environmental stewardship. By situating this discourse within a new political economy of production and governance that Michael Hardt and Antonio Negri have termed empire, I argue that environmental communication scholars should limit the rush to deploy ideological criticism when explaining the corporation's rhetorical motives. Instead, I advocate reading Wal-Mart's rhetoric as a problem of historical conjunctures, a critical move that seeks to highlight, not only the structural interests of capital, but also the centrality of social antagonism. In the case of Wal-Mart, this means accounting for the increased significance of demand to economic production, changes in the composition of sovereignty, and the transgressive function of environmentalism at the beginning of the twenty-first century.     

The production of lumber using chainsaws in Guyana

SUMMARY

The structure, conduct and performance, and the environmental impacts of the chainsaw lumber production sector in Guyana are investigated. Chainsaws are a highly mobile lumber technology that is used to rip or produce lumber within the forest. Chainsaw lumbering operations have become the dominant lumber producer for the domestic market. Production costs are only 53% of wholesale lumber prices. On a ms basis, chainsaw operations' net profit is 80% of the gross price paid for logs at sawmills and more than twice the profit of firms engaged in the harvesting and transportation of logs to sawmills. Sawmills recognize this cost advantage and are increasingly using chainsaws in the production of lumber.

The handling and transportation of chainsawn lumber within the forest is environmentally less damaging than log production. The log recovery rate is 10–15% for chainsaw operations, as compared to the sawmill average of 40–45%. Log residue from chainsaw operations is left within the forest which promotes faster forest regrowth, while that at sawmills is wasted. Chainsaw operations harvest immature trees, engage in the harvesting of selective species, over-harvest trees per unit area of land, and engage in frequent reentry of the forest. Because of these practices, the chainsaw lumber sector is not environmentally sustainable and will require regulation. Policies that follow a non-market solution will be required in regulation.     

Resource-based cities (RBC): a road to sustainability

Resource-based cities (RBC) have made momentous contributions to urbanization in China. However, as natural resources are exhausted, RBC are facing an enormous challenge. In this paper we put forward a resource-based city sustainability index (RCSI) and a resource-based city coordination index (RCCI), including environmental, social, and economic dimensions, adopted three weight scenarios, and selected 13 cities for study. The results: (a) help locate the problems by analyzing both dimensions and indicators; (b) simulate the trends of how RBC emerged, grew, declined, and regenerated; (c) categorize RBC into four types by integrating RCSI and RCCI; (d) give policy makers a holistic and comprehensive perspective in the future urban regulation and management; and (e) highlight a road to sustainability.