How does informational heterogeneity affect the quality of forecasts?

We investigate a toy model of inductive interacting agents aiming to forecast a continuous, exogenous random variable E. Private information on E is spread heterogeneously across agents. Herding turns out to be the preferred forecasting mechanism when heterogeneity is maximal. However in such conditions aggregating information efficiently is hard even in the presence of learning, as the herding ratio rises significantly above the efficient-market expectation of 1 and remarkably close to the empirically observed values. We also study how different parameters (interaction range, learning rate, cost of information and score memory) may affect this scenario and improve efficiency in the hard phase.Comment: 11 pages, 5 figures, updated version (to appear in Physica A

Recovery of Mn as MnO2from spent batteries leaching solutions

The recycling of spent batteries and recovery of metals from them is of great scientific and economic interest, on account of recycling requirement of these wastes and recovery of valuable materials (De Michellis et al., 2007). Usage of recycled materials is diminishing the energy consumption and pollution. It is important that the recycling process to be environmentally friendly, practical and cost-effective. Tests for the process of manganese removal from spent battery leaching solutions, with ammonium peroxodisulfate, prior to recovery of zinc by electrolysis are presented. The experiments were carried out according to a 2 3 full factorial design as a function of ammonium peroxodisulfate concentration, temperature and pH. Because the excessive manganese in the spent batteries leach solutions can cause problems in the process of Zn recovery by electrolysis the main focus of this study is the manganese removal without altering the concentration of zinc in solutions. Data from XRF and AAS during the reaction at different time are presented. Manganese is obtained with high extraction degree as MnO2, which is economic and commercial important with applications in battery industry, water treatment plants, steel industry and chemicals (Pagnanelli et al., 2007). The analysis of variance (ANOVA) was carried out on the extraction yields of Zn after 30min, 1h, 2h and 3h of reaction. The preliminary results denoted that by chemical oxidation with ammonium peroxodisulfate is a suitable method for manganese removal as MnO2 prior zinc recovery by electrolysis, from spent batteries solutions and it could be used in a plant for recycling batteries

A Systems Engineering Approach to Integrated Structural Health Monitoring For Aging Aircraft

The United States Air Force and many of its Coalition partners have extended the original service life of some of their aging aircraft due to fiscal constraints. This life extension often requires increased periodic and in-depth inspections; increasing maintenance costs and resulting in longer periods of aircraft downtime. A structural health monitoring system for aging aircraft could reduce the current inspection burden, and thus decrease costs and system downtime. This presentation describes a baseline systems engineering methodology for system definition of an aging aircraft structural health monitoring system. Analysis was performed to quantify the potential benefit a structural health monitoring affords

Petals of Crocus sativus L. as a potential source of the antioxidants crocin and kaempferol.

Collaboration between Leicester School of Pharmacy - De Montfort Universit, Department of Life, Health and Environmental Sciences - University of L'Aquila, and Department of Biochemistry and Biotechnology - University of Thessaly The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Saffron fromthe province of L'Aquila, in the Abruzzo region of Italy, is highly prized and has been awarded a formal recognition by the European Union with EU Protected Designation of Origin (PDO) status. Despite this, the saffron regions are abandoned by the younger generations because the traditional cultivation of saffron (Crocus sativus L.) is labour intensive and yields only one crop of valuable saffron stamens per year. Petals of the saffron Crocus have had additional uses in traditional medicine and may add value to the crops for local farmers. This is especially important because the plant only flowers between October andNovember, and farmers will need to make the best use of the flowers harvested in this period. Recently, the petals of C. sativus L., which are considered a wastematerial in the production of saffron spice,were identified as a potential source of natural antioxidants. The antioxidants crocin and kaempferol were purified by flash column chromatography, and identified by thin layer chromatography (TLC), HPLC–DAD, infrared (IR), and nuclear magnetic resonance (1H & 13C NMR) spectroscopy. The antioxidant activity was determined with the ABTS and DPPH tests. The antioxidant activities are mainly attributed to carotenoid and flavonoid compounds, notably glycosides of crocin and kaempferol. We found in dried petals 0.6% (w/w) and 12.6 (w/w) of crocin and kaempferol, respectively. Petals of C. sativus L. have commercial potential as a source for kaempferol and crocetin glycosides, natural compounds with antioxidant activity that are considered to be the active ingredients in saffron-based herbal medicine

Cross-Calibration of S-NPP VIIRS Moderate Resolution Reflective Solar Bands Against MODIS Aqua over Dark Water Scenes

The Visible Infrared Imaging Radiometer Suite (VIIRS) is being used to continue the record of Earth Science observations and data products produced routinely from National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) measurements. However, the absolute calibration of VIIRS's reflected solar bands is thought to be biased, leading to offsets in derived data products such as aerosol optical depth (AOD) as compared to when similar algorithms are applied to different sensors. This study presents a cross-calibration of these VIIRS bands against MODIS Aqua over dark water scenes, finding corrections to the NASA VIIRS Level 1 (version 2) reflectances between approximately +1 and 7 % (dependent on band) are needed to bring the two into alignment (after accounting for expected differences resulting from different band spectral response functions), and indications of relative trending of up to 0.35 % per year in some bands. The derived calibration gain corrections are also applied to the VIIRS reflectance and then used in an AOD retrieval, and they are shown to decrease the bias and total error in AOD across the mid-visible spectral region compared to the standard VIIRS NASA reflectance calibration. The resulting AOD bias characteristics are similar to those of NASA MODIS AOD data products, which is encouraging in terms of multi-sensor data continuity