Modeling the wind circulation around mills with a Lagrangian stochastic approach

This work aims at introducing model methodology and numerical studies related to a Lagrangian stochastic approach applied to the computation of the wind circulation around mills. We adapt the Lagrangian stochastic downscaling method that we have introduced in [3] and [4] to the atmospheric boundary layer and we introduce here a Lagrangian version of the actuator disc methods to take account of the mills. We present our numerical method and numerical experiments in the case of non rotating and rotating actuator disc models. We also present some features of our numerical method, in particular the computation of the probability distribution of the wind in the wake zone, as a byproduct of the fluid particle model and the associated PDF method

Calibration of home-made heat dissipation probes for a full rotation of Eucalyptus grandis trees in Brazil

With the aim of proposing an appropriate calibration equation that could be used for Eucalyptus grandis of any size over a rotation of seven years, we carried out direct measurements of water consumption for 3 trees at 19, 45, 54 and 72 months after planting, and measured values of tree transpiration were compared with estimations from HDPs installed on the trunks. The trees used for direct measurements were cut and kept in situ, standing with the bottom inserted in a water tank. The accuracy of the calibration was checked by two independent methods: 1) directs measurements for other individual trees, and 2) through Eddy covariance measurements. We compared direct measurements for 3 trees of different size at the ages of 29 and 65 months with HDP. At the stand level, 15 trees selected to cover the range of sizes of one commercial plantation at the end of the rotation were monitored by HDP over 8 months. The comparison with eddy-covariance measurements was carried out during dry periods. Resulted showed that the calibration developed for these home-made probes can be used with great reliability at the tree and stand scales

Internal friction in advanced Fe-Al intermetallics

We have measured the internal friction and the dynamic modulus of an Fe–38 at.% Al alloy using a forced torsion pendulum working between 10−3 and 10 Hz. The measurements have been carried out as a function of temperature (from room temperature to 1200 K) and as a function of frequency. Two peaks have been observed in the internal friction spectra, at about 780 and 1100 K, which are largely superposed in the intermediate temperature range. Both peaks and the corresponding modulus defect shift in temperature with the oscillation frequency, and can be attributed to relaxation mechanisms. Previous results in the literature seem to indicate that the low temperature peak is the Zener relaxation of Al atoms. The activation energy of the high-temperature peak, referred to as P1 peak because it has not been studied previously, has been determined to be Hact = 2.87 eV, from the results of measurements at different temperatures and frequencies. We discuss the possible mechanisms, which could be responsible of this P1 peak, and suggest that it could be attributed to the intrinsic movements of left angle bracket1 0 0right-pointing angle bracket perfect dislocations over the Peierls barrier by kink pair formation in the B2 ordered FeAl

Rule-based expert system for detection of coffee rust warnings in Colombian crops

The coffee rust is a devastating disease that causes large economic losses across the world. The severity of this disease changes over time so the farmers are not fully aware of the economic importance of the rust disease in the coffee crops. From a computational science perspective, several investigations have been proposed to decrease the effects caused by the coffee rust appearance. One of the most important proposals is the use of expert systems. This paper proposes a novel rule-based expert system in which the knowledge base contains the variables and the set of rules that define the problem. The Buchanan methodology is used to design the proposed system. Experiment results present an average accuracy of 66,67% to detect a correct warning of coffee rust levels

Neisseria oralis sp. nov., isolated from healthy gingival plaque and clinical samples

A polyphasic analysis was undertaken of seven independent isolates of Gram-negative cocci collected from pathological clinical samples from New York, Louisiana, Florida and Illinois and healthy subgingival plaque from a patient in Virginia, USA. The 16S rRNA gene sequence similarity among these isolates was 99.7–100 %, and the closest species with a validly published name was Neisseria lactamica (96.9 % similarity to the type strain). DNA–DNA hybridization confirmed that these isolates are of the same species and are distinct from their nearest phylogenetic neighbour, N. lactamica. Phylogenetic analysis of 16S and 23S rRNA gene sequences indicated that the novel species belongs in the genus Neisseria. The predominant cellular fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C18 : 1ω7c. The cellular fatty acid profile, together with other phenotypic characters, further supports the inclusion of the novel species in the genus Neisseria. The name Neisseria oralis sp. nov. (type strain 6332T = DSM 25276T = LMG 26725T) is proposed

Can ecosystem-based adaptation address the adaptation needs of smallholder farmers? Insights from smallholder coffee and subsistence farmers in central America

In many regions, climate change is having significant adverse impacts on the agricultural production and livelihoods of smallholder farmers, with important consequences for global food security.. Helping smallholder farmers adapt to climate change has therefore become a priority for many of donors and governments. Ecosystem-based Adaptation (EbA, defined as the use of ecosystem services and biodiversity as part of an overall adaptation strategy to help people adapt to the effects of climate change) is one approach that could help smallholder farmers, yet there is still limited knowledge on whether EbA can meet the adaptation needs of smallholder farmers. Here, we provide an overview of what EbA means in the context of smallholder agricultural production. Drawing on expert surveys, field work and household surveys of smallholder coffee and subsistence farmers in Central America, we provide examples of EbA strategies that are suitable for smallholder farmers, characterize how farmers are implementing these strategies, and provide insights into the perceived advantages and drawbacks of different practices for reducing farmer vulnerability. Our study highlights that many agricultural practices that smallholder farmers already use (e.g., agroforestry systems, soil conservation practices, live fences) can be considered EbA, as they are based on the management of biodiversity and ecosystem services and t help and enhance the resilience of agricultural systems. Most smallholder farmers are aware of the relative benefits of EbA practices, but also acknowledge important constraints, such as the cost of setting up the practices and maintenance, andlimited financial, technical and political support. Scaling up the use of EbA through targeted government policies, extension services and farmer programs could not only help smallholder farmers adapt to climate change, but also ensure healthy, sustainable agroecosystems that sustain local livelihoods