Search results for "Modell"
showing 10 items of 2134 documents
IMPIEGO DEL RADIONUCLIDE 137CS PER LA STIMA DEI PROCESSI EROSIVI IN UN BACINO FORESTATO
2008
Il radionuclide cesio-137 (137Cs) è uno dei traccianti più utilizzati per stimare la perdita di suolo per erosione idrica. L'applicazione di questa tecnica alla scala di bacino richiede anzitutto l'acquisizione delle misure del radionuclide in punti distribuiti sulla superficie e l'utilizzo di modelli di conversione idonei a trasformare i valori di 137Cs in quantità di erosione netta o di deposito. La presente memoria si pone l'obiettivo di verificare l'affidabilità del modello di conversione esponenziale per stimare i processi erosivi in terreni interessati da coperture forestali. L'applicazione è stata condotta in un bacino sperimentale della Sila Greca per il quale sono disponibili alcun…
Effect of the junction angle on turbulent flow at a hydraulic confluence
2018
Despite the existing knowledge concerning the hydrodynamic processes at river junctions, there is still a lack of information regarding the particular case of low width and discharge ratios, which are the typical conditions of mountain river confluences. Aiming at filling this gap, laboratory and numerical experiments were conducted, comparing the results with literature findings. Ten different confluences from 45 ∘ to 90 ∘ were simulated to study the effects of the junction angle on the flow structure, using a numerical code that solves the 3D Reynolds Averaged Navier-Stokes (RANS) equations with the k- ϵ turbulence closure model. The results showed that the higher the junction angle, the …
Mechanical And Thermophysical Properties Of Polymers And Chemical Structure: From Computer Simulations To Experimental Data
1988
Chemical structure is related to properties on the basis of results of computer modelling of mechanical behavior. An equation for the shift factor aT,c dependent on temperature T and concentration c is provided, connection to the chain relaxation capability noted, and potential application range of the approach discussed. Constituents of free volume are defined, and effects of individual constituents on mechanical properties.
Prediction of the morphology of polymer-clay nanocomposites
2015
Abstract Polymer nanocomposites have continually attracted increasing interest over the last decade, due to significant improvements they can offer compared to neat polymer matrices. However, the final morphology of a nanocomposite, determined by several variables, can significantly influence the macroscopic properties of the final product. Therefore, it is important to study the interactions between processing, morphology, structure and rheological properties, and the suitability of existing models in order to predict the system's behaviour with change of the main processing variables. In this work, the applicability of a predictive theory based on the Wu model was formulated and proposed …
Wastewater modification processes in a stabilization reservoir: a new mathematical model
2018
The paper presents a mathematical model for the simulation of the ecology of a wastewater stabilization reservoir (WSR). WSRs are hypertrophic aquatic systems devoted to water storage in warm countries where shortage conditions are often encountered. Several factors that affect the stabilization reservoir’s effluent quality were taken into account: hydraulics and hydrology, solar radiation, reaeration, algae, zooplankton, organic matter, pathogens, and sediment-water interactions. The model quantifies the specific influence of each factor on effluent quality, and evaluating the correlation between the different factors. State variables included in the model were: algae, dissolved oxygen, or…
Interactions between cationic amylose derivatives and a pulp fiber model surface studied by molecular modelling
2007
This study was performed in order to obtain more information about the interactions between pulp fibers and acetylated cationic starch derivatives on a molecular scale. The adsorption of the polymers on the fiber surface was studied by simulating polymers on a fiber model surface at 300 K. Fractional atomic coordinates of regenerated cellulose II were used to generate a cellulose fiber surface model. Carboxylate groups were added on the cellulose surface to represent the anionic charge of pulp fiber which originates from hemicelluloses. Amylose chains cationized and acetylated atom by atom were chosen to represent four different starch derivatives. Atomic charges used in simulations were ca…
ICIL: a new ISWI Complex In D.melanogaster Larvae
2008
La comunità educante di fronte alla pandemia: possibili strategie di intervento e nuovi scenari in un’ottica di rete
2022
Quando nel mese di marzo 2020, anche i servizi educativi 0-6 in Italia furono chiusi in base alle misure di sicurezza per pandemia da Covid 19, ci si ritrovò da un giorno all’altro e senza alcuna esperienza pregressa, ad organizzare delle forme di educazione a distanza e di sostegno alle famiglie e ai bambini. Nell’articolo, in particolare, descrivo come si è cercato di far fronte all’emergenza nei nidi e nelle scuole dell’infanzia gestiti dal Comune di Palermo e come l’esperienza del primo lock down abbia permesso di mettere a fuoco alcune strategie di intervento che si sono rivelate una risorsa potenzialmente trasferibile in situazioni di normalità. Sottolineo, inoltre, come la necessità …
Parco Agricolo del Gugliotta a Piano Tavola,Carini.Nuove relazioni tra tessuto urbano e tessuto agricolo
2014
Progetto per Carini Ricerca PRIN MIUR UNIPA
La catena del valore nelle organizzazioni produttive di servizi. Il capitale sociale della città
2005
The urban unity-difference, formed of the social community interacting with the human, natural and constructed environments, produces private and social values or benefits. Interactions among the "services supplying urban firm" and the social, economic and natural environments produce value flows that dinamically form and exchange in the value chain. The New Economics approach is used to analyze the functioning principles of such a kind of value chain. Moreover, the application of a multicriterial operational model for the valuation of variations of social capital produced by every kind of private o public "firm-market system" is outlined. The subject is rilevant: in the public decisional c…