1,721,127 research outputs found
Construction and Validation of the Moral Inclusion/Exclusion of Other Groups (MIEG) Scale
No full textMoral exclusion is defined as viewing others as lying beyond the boundary within which moral values and rules of justice apply. In contrast, the process of moral inclusion involves the extension of social justice to several social groups. Thus, both moral inclusion and exclusion are a pivotal dimension in the study of social inequalities. Although the concept of moral inclusion/exclusion has a history of more than 20 years, research still lacks accurate instruments for measuring it. In this article, a first version of a scale that measures moral inclusion/exclusion was constructed and validated. The good reliability and correlation indexes found across the samples suggest that MIEG is a good measure for tapping into moral exclusion/inclusion symptoms
Blatant domination and subtle exclusion: The mediation of moral inclusion on the relationship between social dominance orientation and prejudice
No full textIn this research,we focus on the effects of the individual's social dominance orientation (SDO) on the expression of prejudicial attitudes. Furthermore, we examine the mediational effect of moral exclusion on this relationship. The literature has shown a strong correlation between SDO and prejudice. However,we hypothesize that the processes of moral exclusion (i.e., covert and institutionalized forms of excluding social groups from the community to which the rules of justice apply) should mediate the effect of SDO on the expression of prejudice, particularly with regard to subtle forms of prejudice. The results from 276 Italian participants support this hypothesis. The effects of SDO are mediated by the inclusive level of the moral community, and this effect is stronger for subtle prejudice than for blatant prejudice. The results suggest that modern prejudice is hidden by subtle forms of moral exclusion
Sintesi in situ sol-gel non-idrolitica: un approccio innovativo per la produzione di materiali nanocompositi ibridi a matrice polimerica e biossido di titanio
No full textOggigiorno, i materiali compositi a matrice polimerica sono ampiamente impiegati in molte diverse applicazioni tecnologiche, in particolare nel settore dell’automotive, ma anche nel campo delle celle solari polimeriche, elettrodomestici, industria dell'imballaggio, interni di aeromobili e in dispositivi per l'elettronica.
L'incorporazione di nanoparticelle inorganiche, come ossidi metallici o non metallici, in matrici polimeriche porta a materiali ibridi organici/inorganici caratterizzati da proprietà migliorate rispetto sia a polimeri non caricati sia a polimeri contenenti particelle micrometriche.
Questo progetto ha come scopo la preparazione di nanocompositi organici/inorganici a matrice polimerica caricati con biossido di titanio (TiO2). In seguito, i compositi ottenuti sono stati caratterizzati da un punto di vista chimico, fisico e meccanico.
Utilizzando la già nota chimica delle reazioni sol-gel non-idrolitica (NHSG), nanoparticelle di TiO2 sono state generate in situ in matrici polimeriche al fine di ottenere compositi ibridi nanostrutturati. Quest’approccio ha permesso il superamento dei tipici problemi reologici associati ai metodi convenzionali di miscelazione meccanica.
Il primo stadio di questa ricerca è stato dedicato allo studio della sintesi NHSG, variando il solvente organico, al fine di rendere questo tipo di reazioni idonee per la generazione in situ in matrici polimeriche. La scelta di un adeguato solvente è un passaggio fondamentale poiché questo svolge un doppio ruolo nel processo: la solubilizzazione della matrice polimerica e agisce come ossigeno donatore per la formazione di nanoparticelle di TiO2.
Quattro tipologie di matrici polimeriche sono state caricate con nanoparticelle di biossido di titanio: poli metilemetacrilato (PMMA), due resine epossidiche ampiamente utilizzate a livello industriale (DGEBA e CE), la gomma etilene-propilene-diene (commercialmente conosciuta come EPDM) e poliuretani.
La generazione in situ delle nanoparticelle ha portato a un’omogenea dispersione delle particelle stesse e a un’ottima aderenza all’interfase organico/inorganico come confermato dalle indagini effettuate con microscopia elettronica a scansione. Inoltre, questo metodo ha portato all’ottenimento del contenuto di carica atteso comprovando l’efficacia dell’approccio proposto.
Le termoanalisi dinamico-meccaniche hanno mostrato un significativo aumento del modulo conservativo (E') nella regione gommosa (intervallo di temperatura al di sopra della temperatura di transizione vetrosa), all’aumento del contenuto di nanoparticelle e indipendente dalla matrice utilizzata. Il comportamento appena descritto ha rivelato che l’incorporazione di nanoparticelle di TiO2 porta a un aumento di rigidità rispetto alle matrici non caricate.
Nella regione gommosa, il modulo E' è principalmente influenzato dalla densità di reticolazione della matrice polimerica. Il considerevole aumento registrato di questo parametro, suggerisce che le particelle si comportano non solo come un semplice rinforzo con elevata rigidità, limitando la mobilità delle catene polimeriche, ma anche come un reale “densificatore” di reticolazione.
Da un punto di vista meccanico, le resine epossidiche si sono dimostrate le matrici che più sono state influenzate della presenza delle nanoparticelle, mostrando anche un discreto incremento della durezza e un notevole aumento della temperatura di transizione vetrosa all’aumentare del contenuto di carica.
I compositi a base PMMA/TiO2 hanno mostrato un’inaspettata velocità di foto-degradazione molto elevata quando esposti alla luce ultravioletta. Da una parte l’incorporazione di nanoparticelle di TiO2 ha quindi portato a un miglioramento delle proprietà meccaniche del PMMA puro, ma dall'altra rende questi ibridi eccellenti come materiali monouso grazie alla loro elevata velocità di fotodegradazione.Nowadays, polymeric composite materials are widely employed for many different technological applications especially in the field of the automotive, but also in electronics, polymeric solar cells, household products, packaging industry, aircraft interiors and device components.
The incorporation of inorganic nanoparticles, such as either metal or non-metal oxides, in polymeric matrices leads to organic/inorganic hybrid materials characterized by enhanced properties as compared to both unfilled polymers and polymers filled with micrometric particles.
This project is mainly dedicated to the preparation of organic/inorganic nanocomposites based on polymers as matrix and titanium dioxide (TiO2) as filler. Subsequently, the obtained composites were characterised from a chemical, physical and mechanical point of view.
Exploiting the well-known non-hydrolytic sol-gel (NHSG) chemistry, TiO2 nanoparticles were in situ generated within polymers in order to obtain nanostructured hybrid composites. This approach allowed overcoming the typical rheological problems related to the conventional mixing methods.
First of all, a study was carried out on the NHSG synthesis of TiO2 nanoparticles, using different organic solvents, in order to make these types of reactions suitable for the in situ filler generation in presence of polymers. The organic solvent plays a double role in this process; it dissolves the polymer and acts as oxygen source in the TiO2 nanoparticles formation. For this reason the NHSG reactions have to be previously studied and the solvent has to be carefully chosen.
Four types of polymeric matrices were filled with TiO2 nanoparticles: poly methyl methacrylate (PMMA), two widely used epoxy resins (DGEBA and CE), ethylene-propylene diene monomer rubber (industrially known as EPDM) and polyurethanes.
The in situ filler generation led to homogeneous particles dispersion and remarkable adhesion at the organic/inorganic interphase as confirmed by the scanning electron microscopy investigations. In addition, the reported method led to the expected filler contents proving the effectiveness of this approach.
The dynamic mechanical thermal analyses showed a significant increase of the storage modulus (E') in the rubbery region (temperature range over the glass transition temperature) by increasing the nanoparticles content and independently on the matrix used. This behaviour indicates that the incorporation of nanoparticles is able to increase the stiffness of the pristine polymeric matrices.
In the rubbery region, the E' is governed by the cross-linking density of the polymeric matrix. The observed remarkable increase of this parameter suggests that the particles do not only act as rigid reinforcing filler, constraining the chains mobility, but also as real cross-linking “densifier”.
The PMMA/TiO2 based composites, unexpectedly, showed very fast photodegradation rate when exposed at ultraviolet light. On one hand the incorporation of TiO2 nanoparticles improves the mechanical properties of neat PMMA and on the other hand it makes these hybrids excellent as disposable material thanks to their fast photodegradation.
By a mechanical point of view, the epoxy resins are the matrices most affected by the presence of the TiO2 nanoparticles. These composites also showed an increase of Vickers hardness and remarkable enhancement of the glass transition temperature by increasing the filler content
Aqueous-based synthesis of photocatalytic copper sulfide using sulfur waste as sulfurizing agent /
Full text linkMost of the copper sulfide synthetic approaches developed until now are still facing issues in their procedure, such as long synthesis duration, high energetic consumption, and high implementation costs. This publication reports a facile and sustainable approach for synthesizing copper sulfides on a large scale. In particular, an industrial by-product of sulfur waste was used as a sulfurizing agent for copper sulfide synthesis in a water medium. The reaction was performed in the hydrothermal environment by following a novel proposed mechanism of copper sulfide formation. The investigation of morphological and optical properties revealed that the target products obtained by using waste possess the resembling properties as the ones synthesized from the most conventional sulfurizing agent. Since the determined band gap of synthesis products varied from 1.72 to 1.81 eV, the photocatalytic properties, triggered under visible light irradiation, were also investigated by degrading the methylene blue as a model pollutant. Importantly, the degradation efficiency of the copper sulfide synthesized from sulfur waste was equivalent to a sample obtained from a reference sulfurizing agent since the value for both samples was 96% in 180 min. This very simple synthetic approach opens up a new way for large-scale sustainable production of visible-light-driven photocatalysts for water purification from organic pollutants
Sos Venezuela : an analysis of the anti-Maduro protest movements using Twitter
Full text linkIn this study, we analyze the evolution of the protests after the election of the Venezuelan Constitutional Assembly in 2017. We adopt the idea of a social conflict over diverging opinions about how the world should be. Sharing similar opinion is one basis for a sense of collective identity that facilitates participation in action to bring about desired changes in the world. We approach social conflict as an interaction between different opinion-based groups, in which opinions are formed and transformed leading and supporting different forms of collective action. We analyze Twitter conversations before, during, and after the events of the summer 2017 anti-regime protests in Venezuela. Correspondence and cluster analysis of a corpus of 60,036 tweets is used to investigate the theme and opinions from July to September 2017. Results show that opinions become more extreme and one-sided in response to overt repression and the authority’s lack of negotiation with movements. After the repression of the protests and President Maduro’s successful implementation of an elected Constitutional Assembly, tweets supporting the rule of law and democratic procedures dissipated, while more radical positions strengthened. These finding suggests that democratic principles rest on a precarious relationship between the individual and the authority. Protest movements may arrive at the paradoxical position in which radicalization is the most straightforward response to repression: The most radical positions survive, while the moderate ones are co-opted or suppressed by the regime. We argue that this dynamic may have potentially negative consequences for democracy and social change
Exclusive and inclusive protest in Europe: Investigating values, support for democracy, and life conditions
No full textDissatisfaction with the economic situation and perceived governmental inefficacy in regard to the financial crisis has spawned a widespread feeling of political distrust across Europe. This distrust has been translated into protests against institutional authority that aims at either expanding democratic procedures or supporting xenophobic and populist measures. This research uses European Social Survey data to compare exclusive and inclusive protesters with regard to a number of personal and social values, attitudes toward democratic principles, and different life conditions and socio-economic resources. It also considers contextual factors to investigate how different protesters' profiles are interwoven with socio-economic conditions. The results of a multilevel latent profile analysis show that exclusive and inclusive protesters, despite sharing similar levels of political distrust, differ with regard to key values and political attitudes, and these differences are related to individual and collective living conditions. We argue that unfavourable living conditions play a non-negligible role in increasing the probability of easy (i.e., populist) scapegoat political attitudes. Further support for this hypothesis is provided by the cross-country analysis, which shows that higher levels of exclusive protest are present in countries that were characterized by worse living conditions before the economic crisis
Gomma EPDM rinforzata con silice generata in-situ
No full textgomma EPDM è stata rinforzata generando silice in situ mediante tecnica sol-gel. Il processo in soluzione adottato ha permesso l’ottenimento di campioni a elevata quantità di filler (fino a un 30% in peso). Sia il test a trazione che il comportamento dinamico meccanico hanno dimostrato un netto miglioramento delle proprietà meccaniche dovuto alla presenza del filler rigido in grado di rinforzare la matrice gommosa. Dalle prove a trazione è stato trovato un modulo elastico iniziale significativamente incrementato se confrontato a quello teorico calcolato dall’equazione di Smallwood-Guth-Einstein considerando un semplice meccanismo di rinforzo idrodinamico
Measuring support for intergroup hierarchies: Assessing the psychometric proprieties of the Italian Social Dominance Orientation7 Scale
Full text linkThis study presents the psychometric proprieties of the Italian version of the Social Dominance Orientation7 (SDO7) Scale, originally developed by Ho et al. (2015). We recruited a convenience sample (N = 497) to answer an online self-report questionnaire, including the SDO7 Scale and other relevant convergent and divergent measures. The confirmatory factor analysis revealed that SDO7 presents a satisfactory fit to the data, both as a two-correlated factor structure and as a one-dimensional measure. The two-correlated factor structure is confirmed as composed by two subdimensions as in the original version: the SDO-Dominance (SDO-D) and the SDO-Anti-Egalitarianism (SDO-E). Since the total SDO7 score measures people’s support for asymmetrical group relationships, the SDO-D is concerned with people’s support for dominant-submissive forms of intergroup relationships whereas the SDO-E refers to the desire to support intergroup inequalities. The scale and subscales also present satisfactory indexes of reliability as well as convergent and divergent validity
Double role of polyethylene glycol in the microwaves-assisted non-hydrolytic synthesis of nanometric TiO<sub>2</sub>: Oxygen source and stabilizing agent
No full textThe microwaves-assisted reaction between titanium(IV) tetrachloride and polyethylene glycol (PEG) represents a novel non-aqueous sol–gel route for synthesizing surface-stabilized titanium dioxide nanoparticles. X-ray powder diffraction measurements showed the exclusive presence of anatase phase. Transmission electron microscopy investigations revealed that the particles are nearly uniform in shape with sizes ranging from 4 to 8 nm and a low degree of agglomeration. The presence of covalently bonded PEG chains on the particles surface has been shown by Fourier transform infrared (FT-IR) spectroscopy. This surface functionalization greatly enhances the dispersibility of the particles in water, as observed by dynamic light scattering and zeta-potential analyses. Furthermore, the investigation of the reaction by-products by a combination of FT-IR and high-performance liquid chromatography (HPLC-Mass) techniques allowed a deeper insight into the reaction mechanism suggesting a double role of PEG as a stabilizing agent and an oxygen source
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