3,306 research outputs found
Accuracy and Precision of Shallow-Water Photogrammetry from the Sea Surface
No full textMapping shallow-water bathymetry and morphology represents a technical challenge. In fact, acoustic surveys are limited by water depths reachable by boat, and airborne surveys have high costs. Photogrammetric approaches (either via drone or from the sea surface) have opened up the possibility to perform shallow-water surveys easily and at accessible costs. This work presents a simple, low-cost, and highly portable platform that allows gathering sequential photos and echosounder depth values of shallow-water sites (up to 5 m depth). The photos are then analysed in conjunction with photogrammetric techniques to obtain digital bathymetric models and orthomosaics of the seafloor. The workflow was tested on four repeated surveys of the same area in the Western Mediterranean and allowed obtaining digital bathymetric models with centimetric average accuracy and precision and root mean square errors within a few decimetres. The platform presented in this work can be employed to obtain first-order bathymetric products, enabling the contextual establishment of the depth accuracy of the final products
Direct replacement of antibodies with molecularly imprinted polymer (MIP) nanoparticles in ELISA - development of a novel assay for vancomycin
No full textA simple and straightforward technique for coating microplate wells with molecularly imprinted polymer nanoparticles (nanoMIPs) to develop ELISA type assays is presented here for the first time. NanoMIPs were synthesized by a solid phase approach with immobilized vancomycin (template) and characterized using Biacore 3000, dynamic light scattering and electron microscopy. Immobilization, blocking and washing conditions were optimized in microplate format. The detection of vancomycin was achieved in competitive binding experiments with a HRP-vancomycin conjugate. The assay was capable of measuring vancomycin in buffer and in blood plasma within the range 0.001-70 nM with a detection limit of 0.0025 nM (2.5 pM). The sensitivity of the assay was three orders of magnitude better than a previously described ELISA based on antibodies. In these experiments nanoMIPs have shown high affinity and minimal interference from blood plasma components. Immobilized nanoMIPs were stored for 1 month at room temperature without any detrimental effects to their binding properties. The high affinity of nanoMIPs and the lack of a requirement for cold chain logistics make them an attractive alternative to traditional antibodies used in ELIS
Drones as tools for monitoring beach topography changes in the Ligurian Sea (NW Mediterranean)
No full text
Una difficile modernità. Tradizioni di ricerca e comunità scientifiche in Italia 1890-1940
No full textIl volume raccoglie gli atti del convegno di studi svoltosi dal 9 all'11 settembre 1998, sotto gli auspici dell'ASSTI- Associazione per la storia della Scienza e della Tecnica -, dell'Istituto Italiano per gli studi filosofici, del CDEC - Centro di documentazione ebraica contemporanea- dell'istittuto nazionale per lòa fisica della materia e dell'Università di Pavia. I contributi raccolti affrontano lo studio delle comunità scientifiche italiane e delle loro tradizioni di ricerca, dei luoghi e delle strutture dell'operare scientifico e tecnico, delle forme di circolazione dei saperi disciplinari. Una postfazione a firma dei curatori conclude il volume
Role of wind events in the generation of (sub)mesoscale structures and their implications on the biological activity of the North West Mediterranean Sea
No full textWe study the mesoscale dynamics in the Ligurian Basin (NW Mediterranean Sea), combining the use of numerical models with satellite and in situ data. To this end, we use the Regional Ocean Modeling System (ROMS) configured at a resolution of 3 Km for a domain covering the West Mediterranean Sea. The model is forced with daily-mean boundary (oceanic) conditions extracted from MERCATOR, and with three-hourly winds, extracted from COSMO-7, models. Analysis showed the formation of intense EKE, including mesoscale eddy structures, in association with strong wind episodes. Strong eddy activities have an impact on the dynamics of the MLD, thus conditioning higher productivity episodes with periods of intense vertical mixing. Wind-induced mesoscale oceanic dynamics has also implications on the transport of pollutants and/or of suspended matter across the Basin, with impacts for the risk assessment
of adjacent coastal regions
Una difficile modernità-Tradizioni di ricerca e comunità scientifiche in Italia: 1890-1940
No full textAn oceanographic model of the Pelagos Area as essential tool for cetacean habitat modelling
No full textAccuracy of sand beach topography surveying by drones and photogrammetry
No full textBeaches are characterized by high morphodynamic activity, and high-frequency measurements are needed to understand their states and rates of change. Ideally, beach survey methods should be at once accurate, rapid and low-cost. Recently, unmanned aerial systems (drones) have been increasingly utilized to measure beach topography. In this paper, we present a review of the state of art in drones and photogrammetry for beach surveys and the respective achieved measurement quality (where reported). We then show how drones with a minimal configuration and a low-cost setup can meet the high accuracy and rapidity required for beach surveys. To test a minimal drone and ground control point configuration, we used consumer-grade equipment to perform the same flight path with different cameras and at different altitudes. We then used photogrammetry to produce digital elevation models of the beach. Using a GNSS-RTK system, we collected 2950 independent control points to evaluate the accuracy of the digital elevation models. Results show that, once a few potential sources of uncertainties in the final digital elevation model are taken into account, the average RMSE(z) of the digital elevation models was ~5 cm, with a survey efficiency of ca. 3 m2 min−1. Digital elevation models taken at different times were used to calculate the before–after sediment budget following a storm that hit a sandy coast in Sylt Island at the German North Sea coast
- …
