Search results for "solution"
showing 10 items of 5638 documents
Object-based image analysis technique for gully mapping using topographic data at very high resolution (VHR)
2018
An accurate mapping of gullies is important since they are still major contributors of sediment to streams. Mapping gullies can be difficult because of the presence of dense canopy, which precludes the identification through aerial photogrammetry and other traditional remote sensing methods. Moreover, the wide spatial extent of some gullies makes their identification and characterization through field surveys a very large and expensive proposition. One cheaper and more expeditious way to detect gullies can be achieved in terms of morphological characteristics by the Digital Elevation Models (DEMs). The recent widespread availability of very high resolution (VHR) imagery, such as LIDAR data,…
3D ERT for the study of an ancient wall covered by precious mosaics
2009
The DC electrical tomography (ERT) is still a method scarcely diffused for the study of masonry of recent and ancient buildings, in spite of the very high resolution power of this methodology. The major limitation on ERT applicability on precious surfaces (like masonries or floors with fresco or mosaic covering) depends on the method of current injection: usually it is necessary to drive electrodes (small nails) into small perforations on the surfaces, to obtain sufficiently high current values (to produce good signal to noise ratio). An interesting application of the MYG array (that reduces significantly, compared to other classical arrays, the number of electrodes utilized for current inj…
Determination of pesticides and veterinary drug residues in food by liquid chromatography-mass spectrometry: A review
2015
Monitoring of pesticides and veterinary drug residues is required to enforce legislation and guarantee food safety. Liquid chromatography-mass spectrometry (LC-MS) is the prevailing technique for assessing both types of residues because LC offers a versatile and universal separation mechanism suitable for non-gas chromatography (GC) amenable and the majority of GC-amenable compounds. This characteristic becomes more relevant when LC is coupled to MS because the high sensitivity and specificity of the detector allows to apply generic sample preparation procedures, which simultaneously extract a wide variety of residues with different physico-chemical properties. Determination of metabolites …
An equivalent single-layer model for magnetoelectroelastic multilayered plate dynamics
2012
Abstract An equivalent single-layer model for the dynamic analysis of magnetoelectroelastic laminated plates is presented. The electric and magnetic fields are assumed to be quasi-static and the first-order shear deformation theory is used. The formulation of the model provides for a preliminary fulfillment of the electro-magnetic governing equations, which allows to determine the electric and magnetic potential as functions of the mechanical variables. Then, by using this result, the equations of motion are written leading to the problem governing equations. They involve the same terms of the elastic dynamic problem weighted by effective stiffness coefficients, which take the magneto-elect…
Fast Axial Scanning in 3D Imaging
2016
We establish the conditions for obtaining fast axial 3D microscopy with constant magnification, invariant resolution, and symmetrical displacement range. We demonstrate that liquid lenses permit the axial scanning free of mechanical movements and vibrations. This allows speeding-up the process and avoiding distortionsin the image of dynamic specimens. Article not available.
Hierarchical Parallelization of an H.264/AVC Video Encoder
2006
Last generation video encoding standards increase computing demands in order to reach the limits on compression efficiency. This is particularly the case of H.264/AVC specification that is gaining interest in industry. We are interested in applying parallel processing to H.264 encoders in order to fulfill the computation requirements imposed by stressing applications like video on demand, videoconference, live broadcast, etc. Given a delivered video quality and bit rate, the main complexity parameters are image resolution, frame rate and latency. These parameters can still be pushed forward in such a way that special purpose hardware solutions are not available. Parallel processing based on…
One-sensor electronic olfactometer for rapid sorting of fresh fruit juices
2001
Abstract A low-cost electronic olfactometer was developed, based on virtual sensors array (an array of signals from a single metal oxide sensor) and on our proprietary semi-automated sampling system. This concept enables us to drastically improve the sensitivity and selectivity of the entire olfactometer to make it suited to food products analysis. Each step of the prototype was checked separately in earlier work, and finally the system performance was evaluated first on pure chemicals, and then at-line for grape juice during grape-harvesting in Champagne. It is shown that over a 3-week vintage period, the drift of the unique-sensor was quite low (absolute baseline value: avg., 2152; std., …
Comparative Study of Different Methods for the Prediction of Drug–Polymer Solubility
2015
In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid ana…
Time-resolving Analysis of Cryotropic Gelation of Water/Poly(Vinyl Alcohol) Solutions via Small Angle Neutron Scattering
2007
The structural transformations occurring in initially homogeneous aqueous solutions of poly(vinyl alcohol) (PVA) through application of freezing (-13 degrees C) and thawing (20 degrees C) cycles is investigated by time resolving small-angle neutron scattering (SANS). These measurements indicate that formation of gels of complex hierarchical structure arises from occurrence of different elementary processes, involving different length and time scales. The fastest process that could be detected by our measurements during the first cryotropic treatment consists of the crystallization of the solvent. However, solvent crystallization is incomplete, and an unfrozen liquid microphase more concentr…
Slow Crystallization Kinetics of Poly(vinyl alcohol) in Confined Environment during Cryotropic Gelation of Aqueous Solutions
2006
The gelation kinetics of aqueous solutions of poly(vinyl alcohol) (PVA) during freezing at −13 °C has been investigated with time-resolved small angle neutron scattering. Crystallization of PVA takes place inside an unfrozen liquid microphase that forms in the matrix of ice crystals and follows a first-order kinetics during the early stages and becomes very slow in the later stages with an apparent Avrami exponent lower than 1. Crystallization of PVA at low temperatures is responsible of formation of strong physical gels upon defrosting, provided that the concentration of PVA is higher than a critical value.