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621.
The search for the optimum design of a given structure is a basic aspect of structural analysis. In recent years there has
been a renewed interest in structural optimization, particularly in the field of composite material structures. The aim is
often to obtain the best solution that is able to respect both the technical and the economic requirements.
In this paper, the optimization process is pursued as the determination of the Pareto-optimal curves for composite material
structures. The problem has been tackled by means of an analytical optimization methodology (trade-off method) appropriately
transformed into a design procedure. A sensitivity analysis is also performed, in order to try out the measure in which the
optimal solutions are affected by the variation of the design variables. Two examples are presented, concerning a hemispherical
shell and a cylindrical shell.
Sommario Molti problemi della ricerca dell'ottimo progettuale presentano la difficoltà di coinvolgere nella soluzione più obiettivi da considerare simultaneamente. Il problema risulta piuttosto complesso (in particolare nel caso di strutture in materiale composito) quando gli obiettivi, spesso contrastanti, hanno natura diversa e quindi risultano non facilmente combinabili fra loro. Tale problema si pone spesso quando si vuole da un lato aumentare l'affidabilità strutturale e dall'altro diminuire i costi della struttura. Nel presente articolo, vengono affrontati alcuni aspetti dell'ottimizzazione di strutture in materiale composito: a tale scopo viene presentata una procedura di ottimizzazione per problemi multi-obiettivo che, avvalendosi del Trade-off method, è in grado di determinare la curva degli ottimi di Pareto. Successivamente viene effettuata un analisi di sensitività allo scopo di valutare la sensibilità delle soluzioni ottimali nei confronti della aleatorietà delle variabili di progetto. Vengono presentati in tal senso due esempi relativi a strutture in materiale composito.相似文献
622.
Drug–Polymer Interactions in Hydrogel‐based Drug‐Delivery Systems: An Experimental and Theoretical Study
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Dr. Filippo Rossi Monica Ferro Paolo Marchini Emanuele Mauri Marta Moioli Prof. Dr. Andrea Mele Prof. Dr. Maurizio Masi 《Chemphyschem》2015,16(13):2818-2825
In drug‐delivery systems, drug transport is a key step, but the interpretation of the transport mechanism is still controversial. Here, we investigated a promising hydrogel library loaded with the anticonvulsant drug ethosuximide (ESM). The self‐diffusion coefficient of ESM was measured using two methods: a direct and advanced measurement with a pulsed field gradient spin‐echo (PFGSE) method, using an NMR spectrometer equipped with high‐resolution magic angle spinning (HR‐MAS) probe, and an indirect one based on fitting in vitro drug‐delivery data. Starting from the experimental data a mathematical model without fitted parameters was developed and all the phenomena involved, that is, adsorption and diffusion, were considered. At low drug concentrations, adsorption prevails and consequently the diffusivity in the gels is lower than that in water. At high drug concentrations, where all adsorption sites are saturated, the diffusion in the gels is similar to that in a water solution. This study may pave the way for better device design. 相似文献
623.
Emanuele Viola 《Combinatorica》2015,35(6):703-747
Suppose each of k≤n o(1) players holds an n-bit number x i in its hand. The players wish to determine if ∑ i≤k x i =s. We give a public-coin protocol with error 1% and communication O(k logk). The communication bound is independent of n, and for k≥3 improves on the O(k logn) bound by Nisan (Bolyai Soc. Math. Studies; 1993). 相似文献
624.
Alberto Cialdea Emanuela Dolce Angelica Malaspina 《Mathematical Methods in the Applied Sciences》2015,38(3):537-547
In this paper, we investigate the internal second, third, and fourth boundary value problems of the three‐dimensional Cosserat elasticity by means of potential theory. The obtained integral representations differ from the classical ones. These results complete the ones related to the first BVP, which have recently been obtained by the authors. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
625.
626.
J. Tillmans P. Hirsch R. Vaubel A. Szent-Györgyi Cl. Zäch Fr. Wohack F. Auerbach H. Zeglin Wilhelm Müller F. Emanuele M. Guastalla B. G. Hartmann F. Hillig K. Taxner F. Löwe D. Schenk D. W. Steuart P. M. Silin Z. A. Silina E. Deér Jr J. F. Snell L. Skazin H. J. Atkinson und G. H. Findlay 《Fresenius' Journal of Analytical Chemistry》1935,101(7-8):296-300
Ohne Zusammenfassung 相似文献
627.
Pierluigi Contucci Emanuele Mingione Shannon Starr 《Journal of statistical physics》2013,151(5):809-829
In this paper we show that d-dimensional Gaussian spin glass models are strongly stochastically stable, fulfill the Ghirlanda-Guerra identities in distribution and the ultrametricity property. 相似文献
628.
Alessandra Lorenzetti Stefano Besco Denis Hrelja Martina Roso Emanuela Gallo Bernhard Schartel Michele Modesti 《Polymer Degradation and Stability》2013
Nanocomposites of a charring polymer (like polyurethane foam) filled with aluminum phosphinate (AlPi) with or without melamine cyanurate (MelCy) have been prepared by microwave processing and their thermal stability and fire behavior have been studied. Results on the interaction between flame retardants and layered silicates were provided as well as detailed investigation of the char strength, which has been carried out using a suitably developed method based on dynamic-mechanic analysis. 相似文献
629.
Roberto Avolio Gennaro Gentile Maurizio Avella Donatella Capitani Maria Emanuela Errico 《Journal of polymer science. Part A, Polymer chemistry》2010,48(23):5618-5629
Organic/inorganic nanocomposites were synthesized from poly(methylmethacrylate) (PMMA) and properly modified silica nanoparticles by in situ polymerization. Methacryloylpropyltrimethoxysilane was selected as nanoparticle surface modifier because it is characterized by unsaturated end groups available to radical reactions, making possible to suppose their participation in the acrylic monomer polymerization. As a result of the above hypothesized reactions, a phase constituted by polyacrylic chains grafted onto modified silica surface was isolated. 29Si and 13C solid‐state nuclear magnetic resonance experiments permitted to analyze this phase in terms of composition and chain mobility as well as to highlight interaction mechanisms occurring between growing PMMA oligoradicals and functional groups onto silica surface. It was demonstrated that this PMMA grafted onto silica surface acts as an effective coupling agent and assures a good dispersion of nanoparticles as well as a strong nanoparticle/matrix interfacial adhesion. As a result of strong interactions occurring between phases, a significant increase of the glass transition temperature was recorded. Finally, the abrasion resistance of PMMA in the hybrids was significantly improved as a result of a different abrasion propagation mechanism induced by silica particles thus overcoming one of the most serious PMMA drawback. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
630.
Emanuele Attolino Filippo Bonaccorsi Felicia D'Andrea Karel Křenek Karel Bezouška 《Journal of carbohydrate chemistry》2013,32(3):156-171
This article has been retracted. 相似文献