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p. 322-362
Received: 2 December 2010; in revised form: 19 January 2011 / Accepted: 24 January 2011 / Published: 28 January 2011
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| Download PDF Full-text (468 KB) | Download XML Full-text Abstract: About 130 studies were analyzed to compare farm-level energy use and global warming potential (GWP) of organic and conventional production sectors. Cross cutting issues such as tillage, compost, soil carbon sequestration and energy offsets were also reviewed. Finally, we contrasted E and GWP data from the wider food system. We concluded that the evidence strongly favours organic farming with respect to whole-farm energy use and energy efficiency both on a per hectare and per farm product basis, with the possible exception of poultry and fruit sectors. For GWP, evidence is insufficient except in a few sectors, with results per ha more consistently favouring organic farming than GWP per unit product. Tillage was consistently a negligible contributor to farm E use and additional tillage on organic farms does not appear to significantly deplete soil C. Energy offsets, biogas, energy crops and residues have a more limited role on organic farms compared to conventional ones, because of the nutrient and soil building uses of soil organic matter, and the high demand for organic foods in human markets. If farm E use represents 35% of total food chain E use, improvements shown of 20% or more in E efficiency through organic farm management would reduce food-chain E use by 7% or more. Among other food supply chain stages, wholesale/retail (including cooling and packaging) and processing often each contribute 30% or more to total food system E. Thus, additional improvements can be obtained with reduced processing, whole foods and food waste minimization.
p. 363-395
Received: 6 December 2010; in revised form: 17 January 2011 / Accepted: 19 January 2011 / Published: 31 January 2011
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| Download PDF Full-text (719 KB) | Download XML Full-text Abstract: In the late 1990s, the author conducted research entitled “Modeling the demand and supply structure for food in Asia”. The research was based on a system dynamics method and, using time series datasets up to 1998 to estimate the parameters, tried to figure out the demand and supply structure for food until the year 2010. In this paper, the author introduces an overall research structure and compares previous study results with the latest statistical data provided by the Food and Agricultural Organization, United Nations (FAO).
p. 396-409
Received: 1 November 2010; in revised form: 20 January 2011 / Accepted: 28 January 2011 / Published: 15 February 2011
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| Download PDF Full-text (457 KB) | Download XML Full-text Abstract: Groundwater is one of the most valuable resources for drinking water and irrigation in the Maheshwaram Catchment, Central India, where most of the local population depends on it for agricultural activities. An increasing demand for irrigation and the growing concern about potential water contamination makes imperative the implementation of a systematic groundwater-quality monitoring program in the region. Nonetheless, limited funding and resources emphasize the need to achieve a representative but cost-effective sampling strategy. In this context, field observations were combined with a geostatistical analysis to define an optimized monitoring network able to provide sufficient and non-redundant information on key hydrochemical parameters. A factor analysis was used to evaluate the interrelationship among variables, and permitted to reduce the original dataset into a new configuration of monitoring points still able to capture the spatial variability in the groundwater quality of the basin. The approach is useful to maximize data collection and contributes to better manage the allocation of resources under budget constrains.
p. 410-423
Received: 9 January 2011 / Accepted: 9 February 2011 / Published: 16 February 2011
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| Download PDF Full-text (415 KB) | Download XML Full-text Abstract: Because of concerns over the construction industry‘s heavy use of cement and the general dissatisfaction with the performance of building envelopes with respect to durability, there is a growing demand for a novel class of ―green‖ binders. Geopolymer binders have re-emerged as binders that can be used as a replacement for Portland cement given their numerous advantages over the latter including lower carbon dioxide emissions, greater chemical and thermal resistance, combined with enhanced mechanical properties at both normal and extreme exposure conditions. The paper focuses on the use of geopolymer binders in building applications. It discusses the various options for starting materials and describes key engineering properties associated with geopolymer compositions that are ideal for structural applications. Specific properties, such as compressive strength, density, pore size distribution, cumulative water absorption, and acid resistance, are comparable to the specifications for structures incorporating conventional binders. This paper presents geopolymer binders, with their three dimensional microstructure, as material for structural elements that can be used to advance the realization of sustainable building systems.
p. 424-442
Received: 6 December 2010; in revised form: 27 January 2011 / Accepted: 31 January 2011 / Published: 16 February 2011
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| Download PDF Full-text (237 KB) | Download XML Full-text Abstract: Many indicator-based methods for the environmental assessment of farming systems have been developed. It is not the absolute values of the indicators that reveal whether the impact of a system is acceptable, but rather the distance between these values and some reference values. We reviewed eight frameworks for the environmental assessment of agricultural systems that define reference values for their indicators. We analyzed the methods used to establish reference values and explored how to improve these methods to increase their usage and relevance. This analysis revealed a striking diversity of terminology, sources, and modes of expression of results. Normative reference values allow the assessment of a single system with a previously defined value; Relative reference values are based on indicator values for similar systems or a reference system. Normative reference values can be Science-based or Policy-based . A science-based normative reference value can be a Target value , which identifies desirable conditions, or an Environmental limit , which is the level beyond which conditions are unacceptable. The quantification of the uncertainty of reference values is a topic which is barely explored and warrants further research. Reference values present a means of introducing site specificity into methods for environmental assessment which seems, at present, largely under-exploited.
p. 443-464
Received: 3 December 2010; in revised form: 24 January 2011 / Accepted: 26 January 2011 / Published: 16 February 2011
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| Download PDF Full-text (249 KB) | Download XML Full-text Abstract: Environmental considerations have called for new developments in building technologies to bridge the gap between this need for lower impacts on the environment and ever increasing comfort. These developments were generally directed at the reduction of the energy consumption during operations. While this was indeed a mandatory first step, complete environmental life cycle analysis raises new questions. For instance, for a typical low thermal energy consumption building, the embodied energy of construction materials now becomes an important component of the environmental footprint. In addition, the usual practice in life cycle analysis now appears to call for some adaptation—due to variable parameters in time—to be implemented successfully in building analysis. These issues bring new challenges to reach the goal of integrated design, construction, commissioning, operation, maintenance, and decommissioning of sustainable buildings.
p. 465-468
Received: 11 January 2011 / Accepted: 11 February 2011 / Published: 16 February 2011
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| Download PDF Full-text (132 KB) | Download XML Full-text Abstract: The authors are to be congratulated for their comprehensive research work on the use of RCA as aggregate in structural grade concrete [1], but some of their conclusions with regard to the effect of aggregate type and RCA content on the fresh and hardened properties of concrete made with coarse RCA, termed RAC for brevity, need discussion.
p. 469-499
Received: 18 January 2011; in revised form: 17 February 2011 / Accepted: 18 February 2011 / Published: 23 February 2011
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| Download PDF Full-text (698 KB) | Download XML Full-text Abstract: The need for integrated methodological framework for sustainability assessment has been widely discussed and is urgent due to increasingly complex environmental system problems. These problems have impacts on ecosystems and human well-being which represent a threat to economic performance of countries and corporations. Integrated assessment crosses issues; spans spatial and temporal scales; looks forward and backward; and incorporates multi-stakeholder inputs. This study aims to develop an integrated methodology by capitalizing the complementary strengths of different methods used by industrial ecologists and biophysical economists. The computational methodology proposed here is systems perspective, integrative, and holistic approach for sustainability assessment which attempts to link basic science and technology to policy formulation. The framework adopts life cycle thinking methods—LCA, LCC, and SLCA; stakeholders analysis supported by multi-criteria decision analysis (MCDA); and dynamic system modelling. Following Pareto principle, the critical sustainability criteria, indicators and metrics (i.e. , hotspots) can be identified and further modelled using system dynamics or agent based modelling and improved by data envelopment analysis (DEA) and sustainability network theory (SNT). The framework is being applied to development of biofuel supply chain networks. The framework can provide new ways of integrating knowledge across the divides between social and natural sciences as well as between critical and problem-solving research.
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