3,369 research outputs found
Tracking ocean wave spectrum from SAR images
An end to end algorithm for recovery of ocean wave spectral peaks from Synthetic Aperture Radar (SAR) images is described. Current approaches allow precisions of 1 percent in wave number, and 0.6 deg in direction
Effects of Cathode Configuration on Hall Thruster Cluster Plume Properties
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76620/1/AIAA-24636-518.pd
Low NO sub x heavy fuel combustor concept program
A gas turbine technology program to improve and optimize the staged rich lean low NOx combustor concept is described. Subscale combustor tests to develop the design information for optimization of the fuel preparation, rich burn, quick air quench, and lean burn steps of the combustion process were run. The program provides information for the design of high pressure full scale gas turbine combustors capable of providing environmentally clean combustion of minimally of minimally processed and synthetic fuels. It is concluded that liquid fuel atomization and mixing, rich zone stoichiometry, rich zone liner cooling, rich zone residence time, and quench zone stoichiometry are important considerations in the design and scale up of the rich lean combustor
Behavior studies related to pesticides: agricultural chemicals and Iowa farmers
Chemicals play significant roles in agriculture today. In the United States they contribute to the immense capability of farmers to produce food and fiber. They are viewed as promising steps in economic development in parts of the world where population grows faster than food production.https://lib.dr.iastate.edu/specialreports/1046/thumbnail.jp
Levelling foods for priority micronutrient value can provide more meaningful environmental footprint comparisons
A growing literature in Life Cycle Assessment seeks to better inform consumers, food policymakers, food supply chain actors, and other relevant stakeholders about how individual foods contribute to sustainable diets. One major challenge involves accurately capturing potential trade-offs between nutritional provision and environmental impacts associated with food production. In response, food system sustainability literature has turned increasingly to nutritional Life Cycle Assessment, which assesses the environmental footprints of different foods while accounting for nutritional value. Here we provide examples that show how environmental footprints based on a priority micronutrient-focused functional unit can provide nutritionally meaningful insights about the complexities involved in sustainable food systems. We reinforce the idea that there are limitations in using single-value nutrition-environment scores to inform food guidance, as they do not adequately capture the complex multi-dimensionality and variation involved in healthy and sustainable food systems. In our discussion we highlight the need for future agri-food sustainability assessments to pay attention to regional nutritional and environmental variation within and between commodities, and to better interpret trade-offs involved in food substitutions
Correspondence from E.B. Lovejoy, August 13, 1862
Correspondence from E.B. Lovejoy regarding absent soldiers from Androscoggin Countyhttps://digitalmaine.com/absent_soldiers/1005/thumbnail.jp
Resilient distributed collection through information speed thresholds
Part 6: Large-Scale Decentralised SystemsInternational audienceOne of the key coordination problems in physically-deployed distributed systems, such as mobile robots, wireless sensor networks, and IoT systems in general, is to provide notions of “distributed sensing” achieved by the strict, continuous cooperation and interaction among individual devices. An archetypal operation of distributed sensing is data summarisation over a region of space, by which several higher-level problems can be addressed: counting items, measuring space, averaging environmental values, and so on. A typical coordination strategy to perform data summarisation in a peer-to-peer scenario, where devices can communicate only with a neighbourhood, is to progressively accumulate information towards one or more collector devices, though this typically exhibits problems of reactivity and fragility, especially in scenarios featuring high mobility. In this paper, we propose coordination strategies for data summarisation involving both idempotent and arithmetic aggregation operators, with the idea of controlling the minimum information propagation speed, so as to improve the reactivity to input changes. Given suitable assumptions on the network model, and under the restriction of no data loss, these algorithms achieve optimal reactivity. By empirical evaluation via simulation, accounting for various sources of volatility, and comparing to other existing implementations of data summarisation algorithms, we show that our algorithms are able to retain adequate accuracy even in high-variability scenarios where all other algorithms are significantly diverging from correct estimations
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