794 research outputs found
Changes in the thermal growing season in Nordic countries during the past century and prospects for the future
The start, end, duration and intensity of the thermal growing season (the period with mean daily temperatures exceeding 5°C) during the past century (1890-1995) was analysed at nine sites in the Nordic region. Statistical comparisons were made between three adjacent 35-year periods. The results indicate that the growing season lengthened considerably at all sites between 1891-1925 and 1926-1960. Lengthening has continued at a slower rate up to the present at the eight Fennoscandian sites but not at the Icelandic site. In contrast, the intensity of the growing season, expressed by effective temperature sum above 5°C, which increased at all sites between the first two periods, has decreased slightly at all locations except Turku in recent decades. Under three scenarios, representing the range of estimated greenhouse gas-induced warming by the 2050s, the growing season is expected to lengthen at all sites. For a “Central” scenario, the greatest lengthening is computed for southern and western Scandinavia (7-8 weeks) with smaller changes in Finland (4 weeks) and Iceland (3 weeks). With a lengthening growing season during the past century in Fennoscandia, there are likely to have been impacts on natural and managed ecosystems. Some evidence of recent biotic and abiotic effects already exists, but other indicators of long-term change remain to be analysed
Knowledge value added as a methodology to evaluate the Office of Force Transformation's Wolf-PAC / Stiletto program concepts
With the DoD acquisition of programs and projects becoming increasingly expensive, it is imperative that the method or measure for determining value for a particular project, real or conceptual, be identified and used enterprise-wide. The form of analysis known as the Knowledge Value Added (KVA) methodology, KVA will evaluate the Office Force Transformation Wolf-PAC / Stiletto concepts. This thesis will explore two distinctly different areas which demonstrate the KVA method's use and benefit: 1. The use of the KVA method to find improvements in a Command and Control (C2) process, and 2. To demonstrate the increase value that the Stiletto ship brings to littoral operations (i.e., Mine hunting). The resulting values will be compared in varying notional scenarios to assess potential improvements for knowledge processes. This method of analysis will demonstrate how a reengineered process, resulting from the KVA method, enables organizations to maximize knowledge creation and production capacity.http://archive.org/details/knowledgevaluedd109452557Approved for public release; distribution is unlimited
Rotor blade construction for circulation control aircraft
A circulation control aircraft rotor blade having a spanwise Coanda surface 16 and a plurality of spanwise extending flexible composite material panels 18 cooperating with the surface to define slots for the discharge of compressed air from within the blade with each panel having first flexure means 60 associated with screw adjustments 36 for establishing a slot opening preload and second flexure means 62 associated with screw adjustments 38 for establishing a slot maximum opening
THE IMPLICATIONS OF A NORTH AMERICAN FREE TRADE AREA FOR AGRICULTURE
This is one of two papers commissioned by the International Agricultural Trade Research Consortium on various aspects related to the agricultural sector of a prospective North American Free Trade Agreement. The companion paper to this one has been prepared by a working group chaired by Thomas Grennes, North Carolina State University. To minimize duplication with the Grennes paper, this paper has given greater attention to the general trade policy issues raised by a NAFTA, institutional factors, additional commodity detail in cereals, fruit and vegetables, and the relevance of other regional trade agreements such as the Canada-U.S. Trade Agreement. This work has also benefitted from an earlier report and its annexes, prepared for the Fraser Institute, under the direction of Tim Josling.International Relations/Trade,
Climate change and mental health
There is a gap in the knowledge concerning the long-term and gradual impacts of climate change on mental health. This discussion paper summarises the expected impacts of the ongoing climate change on mental health in Finland. This discussion paper is intended to open the discussion concerning mental health on the actions and concrete measures we need for mitigation and adaptation to the ongoing climate change in Finland. It provides nine science-based recommendations for implementation in the integrated services for social affairs and health in Finland
Esiselvitys ilmastonmuutokseen sopeutumisesta Suomessa / A preliminary examination of adaptation to climate change in Finland
Using impact response surfaces to analyse the likelihood of impacts on crop yield under probabilistic climate change
Conventional methods of modelling impacts of future climate change on crop yields often rely on a limited selection of projections for representing uncertainties in future climate. However, large ensembles of climate projections offer an opportunity to estimate yield responses probabilistically. This study demonstrates an approach to probabilistic yield estimation using impact response surfaces (IRSs). These are constructed from a set of sensitivity simulations that explore yield responses to a wide range of changes in temperature and precipitation. Options for adaptation and different levels of future atmospheric carbon dioxide concentration [CO2] defined by representative concentration pathways (RCP4.5 and RCP8.5) were also considered. Model-based IRSs were combined with probabilistic climate projections to estimate impact likelihoods for yields of spring barley (Hordeum vulgare L.) in Finland during the 21st century. Probabilistic projections of climate for the same RCPs were overlaid on IRSs for corresponding [CO2] levels throughout the century and likelihoods of yield shortfall calculated with respect to a threshold mean yield for the baseline (1981–2010). Results suggest that cultivars combining short pre- and long post-anthesis phases together with earlier sowing dates produce the highest yields and smallest likelihoods of yield shortfall under future scenarios. Higher [CO2] levels generally compensate for yield losses due to warming under the RCPs. Yet, this does not happen fully under the more moderate warming of RCP4.5 with a weaker rise in [CO2], where there is a chance of yield shortfall throughout the century. Under the stronger warming but more rapid [CO2] increase of RCP8.5, the likelihood of yield shortfall drops to zero from mid-century onwards. Whilst the incremental IRS-based approach simplifies the temporal and cross-variable complexities of projected climate, it was found to offer a close approximation of evolving future likelihoods of yield impacts in comparison to a more conventional scenario-based approach. The IRS approach is scenario-neutral and existing plots can be used in combination with any new scenario that falls within the sensitivity range without the need to perform new runs with the impact model. A single crop model is used for demonstration, but an ensemble IRS approach could additionally capture impact model uncertainties.peerReviewe
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