34 research outputs found

    Historical developments in Dutch gas systems: Unravelling safety concerns in gas provision

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    This paper identifies safety concerns that arise from ongoing technical and institutional changes in the Dutch gas sector. The Netherlands has a well-developed gas infrastructure that primarily transports natural gas, although its constituting features are undergoing major changes. We identify three historical developments, and show how (1) ongoing effects of liberalization; (2) earthquakes in the Groningen-area; and (3) commitment to climate goals affect safety. Between trends of ongoing decentralization and a growing variety of gas producers, the most urgent concerns relate to the operation of low- and medium pressure distribution grids. Natural gas is losing its prominent role, leaving system operators faced with trade-offs induced by a declining share of customers. At the same time, responsibilities for new gas technologies are allocated over a growing number of actors. In illustrating how safety practices have evolved in line with incremental technological and institutional developments over the last half century, this article elaborates how sudden changes in constitutional features of infrastructural systems might jeopardize system safety

    Forest inventory in the digital remote sensing age

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    Applications of sampling theory together with the technical developments in the field of remote sensing have opened new paths in forest inventory. This paper presents an overview of ongoing research in the field of automatic feature extraction and pattern recognition, which may provide options towards a fully automated forest inventory system. Forest information systems have to provide sufficiently reliable and current information in a suitable form, whilst being both efficient and economical. The methods described, have to be seen as a first step towards an automated forest inventory system. The results presented are satisfying for the specific forest situation, but cannot be generalized for other situations and forest types. More comprehensive research on a variety of stand types, tree species and age classes is required, as different feature extraction approaches may be required on different sensors and different image scales. Given a specific need for information the cost of providing the data should not be higher than the benefit achieved by using modern techniques. In the South African plantation forestry situation with homogenous stands, short rotation and relatively extensive silvicultural operations, stand-oriented image analysis approaches could provide sufficient information at acceptable costs.Revie

    Forest inventory in the digital remote sensing age

    No full text
    Applications of sampling theory together with the technical developments in the field of remote sensing have opened new paths in forest inventory. This paper presents an overview of ongoing research in the field of automatic feature extraction and pattern recognition, which may provide options towards a fully automated forest inventory system. Forest information systems have to provide sufficiently reliable and current information in a suitable form, whilst being both efficient and economical. The methods described, have to be seen as a first step towards an automated forest inventory system. The results presented are satisfying for the specific forest situation, but cannot be generalized for other situations and forest types. More comprehensive research on a variety of stand types, tree species and age classes is required, as different feature extraction approaches may be required on different sensors and different image scales. Given a specific need for information the cost of providing the data should not be higher than the benefit achieved by using modern techniques. In the South African plantation forestry situation with homogenous stands, short rotation and relatively extensive silvicultural operations, stand-oriented image analysis approaches could provide sufficient information at acceptable costs. Keywords: remote sensing, forest inventory, photogrammetry Southern African Forestry Journal No. 206, 2006: 43-5

    A preliminary assessment of utilizable biomass in invading Acacia stands on the Cape coastal plains

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    CITATION: Theron, J. M., et al. 2004. A preliminary assessment of utilizable biomass in invading Acacia stands on the Cape coastal plains. South African Journal of Science, 100(1-2): 123-125.The original publication is available at https://journals.co.zaThe biomass (woody material and foliage) of invasive Australian wattles (Acacia cyclops, A. saligna and A. mearnsii) was estimated in stands where crown cover exceeded 50% on the west coast, Agulhas and Eastern Cape coastal plains. Tree-level models were constructed to estimate biomass of the different plant components of A. cyclops and A. saligna from stem diameter at knee height. An existing volume regression equation for A. mearnsii was adapted and the estimated volumes, based on diameter at breast height, and tree height, were converted to mass. Sample plots were used to estimate mass per unit area by tree component, species and region. Satellite remote sensing conservatively estimated the densely (>50% cover) infested areas at >100 000 ha. The total green (wet) woody biomass with a minimum diameter of 2.5 cm was estimated to be almost 10 Mt or 12 million m3. This is equivalent to the annual intake of roundwood by South African pulp, paper and board mills. A substantial quantity of raw material is therefore available for charcoal, wood composites and paper. Other products could possibly be developed from bark and foliage. Large-scale utilization of biomass will be a demanding task, with potential risks. Risks include environmental damage, and the creation of a dependency, and these will need to be managed carefully.https://journals.co.za/content/sajsci/100/1-2/EJC96202?fromSearch=truePublisher's versio

    Historical developments in Dutch gas systems: Unravelling safety concerns in gas provision

    No full text
    This paper identifies safety concerns that arise from ongoing technical and institutional changes in the Dutch gas sector. The Netherlands has a well-developed gas infrastructure that primarily transports natural gas, although its constituting features are undergoing major changes. We identify three historical developments, and show how (1) ongoing effects of liberalization; (2) earthquakes in the Groningen-area; and (3) commitment to climate goals affect safety. Between trends of ongoing decentralization and a growing variety of gas producers, the most urgent concerns relate to the operation of low- and medium pressure distribution grids. Natural gas is losing its prominent role, leaving system operators faced with trade-offs induced by a declining share of customers. At the same time, responsibilities for new gas technologies are allocated over a growing number of actors. In illustrating how safety practices have evolved in line with incremental technological and institutional developments over the last half century, this article elaborates how sudden changes in constitutional features of infrastructural systems might jeopardize system safety.Economics of Technology and Innovatio

    Integrating terrestrial laser scanning based inventory with sawing simulation

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    Please help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected] Houtkund

    Can industries be parties in collective action? Community energy in an Iranian industrial zone

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    The industrial sector plays a huge role in creating economic growth. While energy is vital for industries to thrive, various factors are undermining the availability of energy including phasing out of fossil fuels, CO2 emission caps and, the large gap between the fast developments of industrial clusters and the energy supply, especially in developing countries. Recently, enabled by renewable energy technologies, a transition process is taking place towards decentralized settings for energy provision where households in neighbourhoods initiate renewable electricity cooperatives. The question addressed in this research is if or to what extent the model of collective action deployed by citizen cooperatives is applicable to collaborations between industries in an industrial cluster. We identified the conditions for the establishment of Industrial Community Energy Systems (InCES) from a collective action perspective by using Ostrom's Institutional Analysis and Development Framework. The case study selected is the industrial city of Arak, one of the largest and most diversified industrial clusters in Iran. Besides desk research, data was also collected by conducting semi-structured interviews and by holding stakeholder workshops. The results of this study highlight the importance of community spirit and trust for the establishment of InCES, unlike citizen cooperatives where finance and environmental attitude are essential. A transparent legal framework to resolve conflicts that might emerge in industrial partnerships is another crucial element given the many differences among industries such as differences in energy demand and in usage patterns.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Energy & IndustryTransport and LogisticsEconomics of Technology and Innovatio
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