Influence of artificial mouth’s directivity in determining Speech Transmission Index

In room acoustics, one of the most used parameters for evaluating the speech intelligibility is the Speech Transmission Index (STI). The experimental evaluation of this STI generally employs an artificial speaker (binaural head) and listener (artificial mouth). In this study, the influence on the measurements of the emission directivity of the artificial mouth was investigated for different acoustic environments and we have found that, in many cases (i.e. big rooms or systems of telecommunications) the results is not sensitive to modifications of the directivity; on the contrary, inside cars, the shape of the whole balloon of directivity is important for determining correct and comparable values and the different mouth studied gives really different results in the same situation

Il caso Catalogna: il principio di autodeterminazione dei popoli e la crisi della sovranità statale

Negli ultimi anni in Europa si sono rafforzate numerose istanze secessioniste da parte di minoranze nazionali che, aspirando all’indipendenza, minano l’integrità territoriale dello Stato in cui risiedono. Tra questi movimenti, quello catalano ha destato un’attenzione particolare soprattutto in seguito a dichiarazioni unilaterali di indipendenza che hanno provocato una violenta reazione da parte delle autorità centrali. Dalle rivendicazioni catalane è emerso il riferimento costante al principio di autodeterminazione dei popoli come base delle pretese. Partendo dalla ricostruzione di detto principio e della sua evoluzione, l'eaborato cerca di far chiarezza sulla possibilità di una sua applicazione al caso Catalogna e sulla possibilità di configurare un diritto di secessione alla luce della disciplina internazionale

The new cloud value chain : a collaborative model for the emerging ecosystem

LAUREA MAGISTRALEL’obiettivo di questo studio è quello di comprendere e descrivere come sta cambiando l’industria del Cloud e quali sono oggi i vantaggi competitivi su cui gli attori possono far leva per generare valore nella filiera. La ricerca si propone di approfondire il tema oggi chiave del Cloud Computing, costruendo un modello che descriva l’attuale catena del valore. A tal proposito, il primo passo è stata un’analisi dettagliata delle diverse definizioni, caratteristiche ed evoluzioni più recenti che hanno interessato questo ambito. Il Cloud Computing rappresenta una tecnologia in rapida crescita, la cui filiera è stata notevolmente rivoluzionata dalla nascita e dalla successiva affermazione dei grandi marketplace e delle mega-piattaforme (successive all’affermazione del modello PaaS) che stanno attualmente dominando il mercato e portando alla nascita di un nuovo ecosistema. Tutti gli attori devono oggi interfacciarsi con nuovi ruoli ed opportunità ma anche con nuove barriere all’interno del business: il modello collaborativo risulta la nuova frontiera per la sopravvivenza ma è anche la chiave per generare nuovi vantaggi competitivi. I modelli esistenti non sono più adatti per rappresentare l’attuale filiera del Cloud Computing: i nuovi ruoli devono quindi essere formalizzati, le nuove dinamiche relazionali ridisegnate ed i tradizionali fattori critici di successo necessitano un profondo ripensamento. A questo scopo, è stato creato un nuovo modello successivamente applicato al mercato italiano per facilitarne così la comprensione. Il modello elaborato ha risposto appieno a tutte le domande di ricerca. L’evoluzione che sta ridefinendo i ruoli esistenti è stata pienamente inquadrata, deducendo quali ruoli ne beneficeranno e quali invece ne saranno sopraffatti. Il modello più profittevole è senza alcun dubbio quello collaborativo. Se gli attori adottassero un approccio competitivo, infatti, verrebbero a mancare le condizioni di equilibrio alla base dell’ecosistema, portando inevitabilmente al predominio dei grandi fornitori di servizi, ovvero i proprietari dei grandi marketplace.The purpose of this study is to describe how the cloud industry is evolving and which sources of competitive advantage are fundamental for the different players in the market. The research deepens the topic of Cloud Computing, with the aim of building a model representing its current supply chain. It starts, thus, by analysing the different definitions of this technology, its main features and its evolution. Then, once the concept will be clearly depicted, the main supply chain models will be individually examined in order to develop a new maturity framework. The Cloud Computing technology is rapidly growing, and its value chain is being deeply revolutionized by the growth of the marketplaces and mega platforms ( following the PaaS model affirmation) , leading to the rise of a new dominating ecosystem. All the players have to manage new roles and opportunities but also to overcome raising barriers: the collaboration is the new frontier for the survival and, in addition, can represent a huge source of competitive advantage for everyone. The existent Cloud Value Chain models are no more suitable to represent the current scenario: therefore, the new roles of the actors must be formalized, the ongoing relationships dynamics must be reshaped, and the traditional critical success factors need to be reviewed. A new model has been elaborated to reach the aforementioned purpose and it’s been applied to the Italian Market to facilitate its comprehension. The evolutions affecting the old roles and the new players have been explained, together with highlighting which companies’ categories are competing well and which ones are instead struggling. The most profitable model is the collaborative one. If the different players adopted a competitive behaviour, indeed, this equilibrium would degenerate and probably the proprietary services providers would be the only survivors

Association of nicotinamide with parabens: effect on solubility, partition and transdermal permeation

Nicotinamide is a hydrophilic molecule, freely soluble in water, used as cosmetic active ingredient for its moisturizing and depigmenting properties. Moreover it has the ability to augment the solubility of poorly water-soluble molecules acting as a hydrotrope. The aim of this work was to study the effect of nicotinamide on the transdermal permeation of methyl, ethyl, propyl and butyl paraben. Parabens flux was measured in vitro in the presence and absence of different amounts of nicotinamide. From solubility studies it was found that nicotinamide forms one or more complexes with methyl, propyl and butyl paraben in water, even though with low stability constants. The interaction of ethyl paraben seems to be less easy to explain. The association of nicotinamide with parabens causes a significant reduction of the permeability coefficients of these preservatives through rabbit ear skin, caused by a reduction of the stratum corneum/vehicle partition coefficient. The effects of nicotinamide on parabens solubility, permeation and partitioning are potentially very interesting because nicotinamide can facilitate paraben dissolution in aqueous media (solutions, gels), reduce parabens partitioning in the oily phase thus guaranteeing an effective concentration in the water phase in emulsion and reduce transdermal penetration, thus reducing the toxicological ris

Ethyl-paraben and nicotinamide mixtures: apparent solubility, thermal behaviour and X-ray structure of the 1:1 co-crystal

This work aims at investigating the nicotinamide (NA)-ethyl-paraben (EP) binary system both in solution and in the solid state. In particular, the apparent EP solubility in water was studied in the presence of different NA concentrations (between 0.28 and 1.64 M). It was found that the apparent EP solubility increase (nearly twofold) observed at the highest NA concentration tested can be ascribed to a change in the polarity of the solvent mixture, rather than to a direct effect of NA on EP. The effect of fusion and re-crystallization from water or ethanol solutions on EP and NA mixtures was investigated by means of differential scanning calorimetry, elemental analysis and X-ray diffraction both on powder and single crystal. It was discovered that EP and NA form a co-crystal having a 1:1 molar composition that can be easily crystallized from ethanol. Single crystal X-ray analysis of this species revealed that the NA and EP molecules form corrugated layers within which the two components are intimately associated by a dense network of hydrogen bonds. In the presence of an excess NA in solution, the EP-NA co-crystal has lower water solubility with respect to both the single co-crystal formers and precipitates in aqueous solutions at ambient temperature