308 research outputs found

    A 40 Gb/s InP-monolithically integrated DPSK-demolulator enhanced by cross-gain-compensation in an SOA

    Get PDF
    We fabricated and experimentally tested a novel monolithically integrated Indium Phosphide optical circuit for differential phase-shift keying demodulation, which is robust to noise degradations of the received signal. The circuit consists of a one-bit-delay interferometer that demodulates the incoming signal and a semiconductor optical amplifier where the constructive and destructive demodulated outputs synchronously counter-propagate experiencing a reshaping effect. The novel optical circuit has been fabricated for 40 Gb/s signals, and the amplitude signal restoration is demonstrated by comparing the obtained output eye diagrams with those of a commercial fiber-based demodulator. We find a net improvement in the signal to noise ratio when the circuit is fed with a noisy input signal

    waste silica sources as heavy metal stabilizers for municipal solid waste incineration fly ash

    Get PDF
    Abstract The present work discusses a new method, based on the use of silica fume, for heavy metal stabilization. The inertization procedure is reported and compared with other technologies, involving the employ of amorphous silica as stabilizing agent for municipal solid waste incinerator fly ash treatment (i.e. colloidal silica and rice husk ash). The obtained final materials are characterized in terms of chemical composition and phase analysis. The reported method, realized at room temperature, employs all waste or by-product materials. As a consequence it appears to be economically and environmentally sustainable

    Integrated management of ash from industrial and domestic combustion : a new sustainable approach for reducing greenhouse gas emissions from energy conversion

    Get PDF
    This work supports, for the first time, the integrated management of waste materials arising from industrial processes (fly ash from municipal solid waste incineration and coal fly ash), agriculture (rice husk ash), and domestic activities (ash from wood biomass burning in domestic stoves). The main novelty of the paper is the reuse of wood pellet ash, an underestimated environmental problem, by the application of a new technology (COSMOS-RICE) that already involves the reuse of fly ashes from industrial and agricultural origins. The reaction mechanism involves carbonation: this occurs at room temperature and promotes permanent carbon dioxide sequestration. The obtained samples were characterized using XRD and TGA (coupled with mass spectroscopy). This allowed quantification of the mass loss attributed to different calcium carbonate phases. In particular, samples stabilized using wood pellet ash show a weight loss, attributed to the decomposition of carbonates greater than 20%. In view of these results, it is possible to conclude that there are several environmental benefits from wood pellet ash reuse in this way. In particular, using this technology, it is shown that for wood pellet biomass the carbon dioxide conversion can be considered negative

    The use of antimicrobials in italian heavy pig fattening farms

    Get PDF
    Data on antimicrobial use (AMU) in heavy pig production (>150 kg) are limited. The aim of this study was to investigate the AMU in this production. Data from 2015 were collected for 143 fattening farms. The AMU was estimated through a treatment index per 100 days (TI100) using the defined daily dose animal for Italy (DDDAit). When possible, a comparison with the European Medicines Agency’s defined daily doses for animals (DDDvet) was performed. The median TI100 was 10.7 (range, 0.2–49.5). Group treatments represented 94.6% of overall consumption. The AMU calculated using DDDAit and DDDvet were strongly correlated (ρ = 0.976; p < 0.001). The AMU was negatively correlated with injectables use (ρ = −0.46, p < 0.001) and positively correlated with oral products (ρ = 0.21, p = 0.014), premixes (ρ = 0.26, p = 0.002), and mortality (ρ = 0.18; p = 0.027). Farm size was negatively correlated with AMU (ρ = −0.29, p < 0.001). Smaller farms were more frequently above the median TI100 (odds ratio = 2.3, 95% confidence interval = 1.2–4.7), suggesting that they may have lower biosecurity and management standards. The results of this study should provide useful insights for the development of an Italian monitoring system

    Regional to global assessments of phytoplankton dynamics from the SeaWiFS mission

    Get PDF
    Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth\u27s net primary production. For 13. years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface chlorophyll concentration, the primary biological property retrieved from SeaWiFS, have traditionally been used as a metric for phytoplankton abundance and its distribution largely reflects patterns in vertical nutrient transport. On regional to global scales, chlorophyll concentrations covary with sea surface temperature (SST) because SST changes reflect light and nutrient conditions. However, the ocean may be too complex to be well characterized using a single index such as the chlorophyll concentration. A semi-analytical bio-optical algorithm is used to help interpret regional to global SeaWiFS chlorophyll observations from using three independent, well-validated ocean color data products; the chlorophyll a concentration, absorption by CDM and particulate backscattering. First, we show that observed long-term, global-scale trends in standard chlorophyll retrievals are likely compromised by coincident changes in CDM. Second, we partition the chlorophyll signal into a component due to phytoplankton biomass changes and a component caused by physiological adjustments in intracellular chlorophyll concentrations to changes in mixed layer light levels. We show that biomass changes dominate chlorophyll signals for the high latitude seas and where persistent vertical upwelling is known to occur, while physiological processes dominate chlorophyll variability over much of the tropical and subtropical oceans. The SeaWiFS data set demonstrates complexity in the interpretation of changes in regional to global phytoplankton distributions and illustrates limitations for the assessment of phytoplankton dynamics using chlorophyll retrievals alone

    Early detection of cryptic memory and glucose uptake deficits in pre-pathological APP mice

    Get PDF
    Earlier diagnosis and treatment of Alzheimer's disease would greatly benefit from the identification of biomarkers at the prodromal stage. Using a prominent animal model of aspects of the disease, we here show using clinically relevant methodologies that very young, pre-pathological PDAPP mice, which overexpress mutant human amyloid precursor protein in the brain, exhibit two cryptic deficits that are normally undetected using standard methods of assessment. Despite learning a spatial memory task normally and displaying normal brain glucose uptake, they display faster forgetting after a long delay following performance to a criterion, together with a strong impairment of brain glucose uptake at the time of attempted memory retrieval. Preliminary observations suggest that these deficits, likely caused by an impairment in systems consolidation, could be rescued by immunotherapy with an anti-β-amyloid antibody. Our data suggest a biomarker strategy for the early detection of β-amyloid-related abnormalities
    corecore