2,857 research outputs found

    How E-waste challenges environmental governance

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    This article examines how e-waste – waste from electronic and electrical equipment – poses a challenge for environmental governance. The amount of e-waste generated globally has been estimated to reach about 72 billion tons annually by 2017. This article discusses how e-waste challenges the control of illegal trade as well as the prevention of environmental harms. By focusing on the role of state, corporate and civil society actors, insights are gained into the strengths and limitations of the governance framework. These suggest the need for reflection about both practical and theoretical implications that arise for environmental governance

    Challenges in governing the international trade in hazardous waste

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    Flows of transnational environmental crime: case study research on e-waste and timber

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    Despite growing interest in green criminological issues, a need remains to develop research that grasps the complexity and transnational nature inherent to the phenomenon of transnational environmental crime. We hope to contribute to this in our PhD-study which focuses on transnational environmental crime and more in particular on the illegal transport of e-waste and timber. Both of these transnational environmental crime phenomena are inherently linked to globalisation and to transferences of levels or geographies. Therefore we explicitly took the transnational dimension into account and perceived both phenomena as flows. We present the first results of a case study about illegal transports of e-waste and timber, for which a Belgian port served as the research setting. Based on a triangulation of data from document analyses and in-depth interviews, we try to de-anonymize the origin, intermediary and destination locations of these flows. We illustrate the characteristics of illegal transports of e-waste and timber as transnational environmental crime flows. We look at the environmental problems at the basis of their criminalization: what actors are involved, what the nature of the phenomena is and what its impact, harm and vulnerabilities are. This will provide meaning to the second goal of our research which focuses on the governance of transnational environmental crime flows. This second aim is to map governance nodes and networks and pay attention to different actors involved, to their interactions and potentially different finalities. This presentation focuses on the characteristics of illegal transports of e-waste and timber (goal 1) and hints towards the study of their governance (goal 2)

    Hierarchical index sets in algebraic modelling languages

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    Multi-dimensional algebraic modelling languages make extensive use of simple and compound index sets. In this paper the multi-dimensional modelling paradigm is extended with the concept of a hierarchical index set to support the use of hierarchical data structures. The appropriate reference and indexing mechanisms are introduced, together with mechanisms to support various set operations. Special attention is paid to the Cartesian product of two hierarchical index sets. The modelling of multi-stage programming models is supported through the introduction of a hierarchical indexing mechanism. The extensions proposed in this paper are compared to existing facilities designed to support the modelling of hierarchical structures

    A branch-and-bound methodology within algebraic modelling systems

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    Through the use of application-specific branch-and-bound directives it is possible to find solutions to combinatorial models that would otherwise be difficult or impossible to find by just using generic branch-and-bound techniques within the framework of mathematical programming. {\sc Minto} is an example of a system which offers the possibility to incorporate user-provided directives (written in {\sc C}) to guide the branch-and-bound search. Its main focus, however, remains on mathematical programming models. The aim of this paper is to present a branch-and-bound methodology for particular combinatorial structures to be embedded inside an algebraic modelling language. One advantage is the increased scope of application. Another advantage is that directives are more easily implemented at the modelling level than at the programming level

    Size and boundary effects on desiccation cracking in hardened cement paste

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    The density of cracks or size of fragments formed in hardened cement paste upon first drying is affected by specimen size as measured with a crack-impregnation technique in free shrinking specimens with a thickness of 4cm. Fragment size on the drying surface increased with distance away from the specimen corner, resulting in smaller average surface crack densities in larger specimens. Size effect on three- dimensional crack density, that was measured from sections through the impregnated specimens, was weaker. The size effect is explained by higher residual thermal stresses in larger specimens due to the cement hydration process. For comparison a desiccation crack pattern in a 5-mm-thick cement paste layer on a marble substrate was studied. Residual thermal stresses in this specimen were probably low and a uniform crack-pattern with a Gaussian-like fragment size distribution forme

    Organic Matter in Space - an Overview

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    Organic compounds are ubiquitous in space: they are found in diffuse clouds, in the envelopes of evolved stars, in dense star-forming regions, in protoplanetary disks, in comets, on the surfaces of minor planets, and in meteorites and interplanetary dust particles. This brief overview summarizes the observational evidence for the types of organics found in these regions, with emphasis on recent developments. The Stardust sample-return mission provides the first opportunity to study primitive cometary material with sophisticated equipment on Earth. Similarities and differences between the types of compounds in different regions are discussed in the context of the processes that can modify them. The importance of laboratory astrophysics is emphasized.Comment: Introductory overview lecture presented at IAU Symposium 251, "Organic matter in space", held at Hong Kong, February 2008; to appear in IAU Symposium 251 proceedings, Cambridge University Press, ed. S. Kwok et a
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