30 research outputs found
Automated Control Systems and Methods for Underground Crop Harvesters
Methods and devices for automated adjustment of a digging implement during harvest of underground crops are described. Utilizing the devices, a digging implement, e.g., a blade, can be located and maintained at a desired depth as a harvester travels across a field. During use, the digging implement depth controls can be varied as the harvester travels within a single field under different operating conditions, e.g., different soil friability, consistency, etc., thereby preventing crop loss and improving crop yield
Behind the Signs - a global review of fish sustainability information schemes
This paper presents the results of a global review of organisations that provide sustainable fisheries information — including ecolabels, recommendation lists and supermarkets — to consumers and supply chain intermediaries. It examined 17 organisations and key supermarkets that communicate on the sustainability of world fisheries and aquaculture products. Certification schemes assess a relatively small number of specific fisheries and indicate sustainability through labels. Recommendation lists cover more species and areas but in less detail. FAO guidelines for fisheries ecolabelling and aquaculture certification constituted the benchmarks with which improving conformance was found. However, significant variation in fisheries’ assessment exists, affecting the accuracy and precision of information and advice provided. Inconsistent approaches and contradictory advice among certification schemes and recommendation lists potentially increase consumer confusion and reduce their credibility. The review identifies seven critical attributes schemes must address — scope, accuracy, independence, precision, transparency, standardisation and cost-effectiveness — and recommends that certification schemes and recommendation lists enhance their consistency and credibility through compliance with these attributes and FAO guidelines. Fish sustainability information schemes play an important role in securing a sustainable future for the oceans. Uptake of this review’s recommendations should reduce consumer confusion and increase confidence in the benefits of sustainable purchasing
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NACA Research Memorandums
Report presenting a study of the effects of spoilers with fixed heights equal to 2.5 to 4 percent of the airfoil chord on the aerodynamic lift and moment flutter derivatives of oscillating two-dimensional airfoils. Results regarding the typical effects of spoiler deflection, effects of Mach number, and aerodynamic torsional instability boundaries for fixed spoiler heights as affected by airfoil profile are provided
Recommended from our members
NACA Research Memorandums
Report presenting a determination of aerodynamic lift and moment flutter derivatives at high subsonic speeds for a series of two-dimensional airfoils varying in thickness and thickness distribution. An evaluation of the results indicated that wing profile and angle of attack have major effects on flutter derivatives at speeds exceeding the Mach number for steady-state lift divergence. Results regarding lift and moment are provided
Animal movements in fire-prone landscapes
Movement is a trait of fundamental importance in ecosystems subject to frequent disturbances, such as fire-prone ecosystems. Despite this, the role of movement in facilitating responses to fire has received little attention. Herein, we consider how animal movement interacts with fire history to shape species distributions. We consider how fire affects movement between habitat patches of differing fire histories that occur across a range of spatial and temporal scales, from daily foraging bouts to infrequent dispersal events, and annual migrations. We review animal movements in response to the immediate and abrupt impacts of fire, and the longer-term successional changes that fires set in train. We discuss how the novel threats of altered fire regimes, landscape fragmentation, and invasive species result in suboptimal movements that drive populations downwards. We then outline the types of data needed to study animal movements in relation to fire and novel threats, to hasten the integration of movement ecology and fire ecology. We conclude by outlining a research agenda for the integration of movement ecology and fire ecology by identifying key research questions that emerge from our synthesis of animal movements in fire-prone ecosystems