Search results for " Fractal dimension"

showing 3 items of 3 documents

LONG TIME BEHAVIOR OF A SHALLOW WATER MODEL FOR A BASIN WITH VARYING BOTTOM TOPOGRAPHY

2002

We study the long time behavior of a shallow water model introduced by Levermore and Sammartino to describe the motion of a viscous incompressible fluid confined in a basin with topography. Here we prove the existence of a global attractor and give an estimate on its Hausdorff and fractal dimension.

HydrologyShallow water equations Global Attractor Fractal dimension dissipative systemWaves and shallow waterStructural basinSettore MAT/07 - Fisica MatematicaGeologyWaves and Stability in Continuous Media
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Canopy Architecture Appraisal by Fractal Dimension of 'Flordastar' Peach Trees Grafted onto Different Rootstocks

2007

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour, by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara, Barrier, GF677 and MrS 2/5 rootstocks. On digital pictures of leafless, dormant peach tree…

The objective of this research was to evaluate the modification of canopy architecture of ''Flordastar'' peach (Prunus persica L. Batsch) grafted onto rootstocks with different vigour by the use of fractal dimension (D). The hypothesis was that different vigour rootstocks are able to modify the complexity of the branching pattern and that this effect can be assessed by a geometric parameter such as the fractal dimension (D) of the 2D projection of tree branching structure. The observations were carried out in a four-year-old experimental orchard of cv. ''Flordastar'' peach trees grafted onto Ishtara Barrier GF677 and MrS 2/5 rootstocks. On digital pictures of leafless dormant peach trees the tree skeleton was manually depicted by an image analysis software to measure total length and angles of insertion of branches. Bitmaps of the skeleton were then subjected to a specific software (FDCALC) able to calculate D by the "box counting" method. To account for the error introduced by analyzing a three dimensional structure with its 2D projection measurements were done on two images per tree taken from two different viewing angles. Results are shown in relation to tree vigour of the scion/stock combination. Fractal dimension was related to the vigour ranking of the graft combinations tested. In particular vigorous scion/stock combinations showed the highest D.HorticultureCanopy architectureHorticultureRootstockFractal dimensionMathematics
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Mucoadhesive Polymer Hyaluronan as Biodegradable Cationic/Zwitterionic-Drug Delivery Vehicle

2014

Mucoadhesive polymers in pharmaceutical formulations release drugs in mucosal areas. They interact and fix to mucus via molecular interpenetration, etc ., which increase drug bioavailability. Polymers physicochemical properties affect formulation mucoadhesion, rheological behaviour and drug absorption. Hyaluronan (HA) is selected as a mucoadhesive and biodegradable polymer. Geometric, topological and fractal analyses are carried out with program TOPO. Reference calculations are performed with algorithm GEPOL. Procedure TOPO underestimates molecular volume by 0.7%. Error results 5% in surface area and derived topological indices. Solvent-accessible surface is undercalculated by 3%: from hexa…

chemistry.chemical_classificationAbsorption (pharmacology)Chemistrylcsh:RM1-950Cationic polymerizationMedicine (miscellaneous)NanotechnologyPolymerBiodegradable polymerBioavailabilitymedicine absorption; medicine delivery; dipole moment; fractal dimension; metal hyaluronate; mucosalcsh:Therapeutics. PharmacologyChemistry (miscellaneous)Drug deliveryMucoadhesionPharmacology (medical)General Pharmacology Toxicology and PharmaceuticsHydrateNuclear chemistryADMET and DMPK
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