Relevant bibliographies by topics / Compositi

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Compositi'

Author: Grafiati
Published: 4 June 2021
Last updated: 10 March 2023

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Journal articles on the topic "Compositi"

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Grandini, Simone, Giuseppe Chiodera, Walter Devoto, and Angelo Putignano. "Utilizzo razionale dei compositi bulk nella pratica quotidiana." Dental Cadmos 86, no. 09 (September 2018): 802. http://dx.doi.org/10.19256/d.cadmos.09.2018.08.

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Olivito, Renato S., and Rosamaria Codispoti. "Natural Fiber Composites for Structural Strengthening of Constructions." Key Engineering Materials 916 (April 7, 2022): 66–73. http://dx.doi.org/10.4028/p-qg327p.

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Negli ultimi anni vengono studiate le fibre naturali di origine vegetale come lino, juta, canapa, basalto oltre a quelle derivate dal bambù o dall'ananas, per le loro molteplici proprietà. Tra i principali vantaggi che hanno, ricordiamo: la grande disponibilità in natura; sono rinnovabili, hanno una bassa densità e un costo contenuto, nonché proprietà meccaniche che li rendono interessanti per la realizzazione di materiali compositi fibrorinforzati. Sono utilizzati da tempo in vari settori dell'ingegneria: dall'automotive e aerospaziale all'ingegneria civile per la realizzazione di pannelli, pareti ecc. Attualmente l'attenzione è stata focalizzata sulla possibilità di utilizzarli come materiali di rinforzo su strutture in muratura. Il continuo e crescente interesse per la conservazione dei beni storici richiede sistemi di rinforzo di facile utilizzo e affidabili con relative metodologie di calcolo che permettano di valutare la capacità delle strutture murarie esistenti e rinforzate. Tuttavia, i modelli analitici applicabili alle strutture in muratura armata non sono stati sviluppati allo stesso livello di quelli per altri materiali da costruzione moderni. In particolare, esiste un divario tra i risultati sperimentali di elementi murari armati con sistemi innovativi ei risultati ottenuti da modelli analitici. Tutto ciò ha ostacolato un'analisi completa dell'approccio sperimentale che può fornire un prezioso contributo a metodi di progettazione eccessivamente conservativi per soluzioni di rinforzo innovative. Nel presente lavoro, al fine di validarne l'efficacia vengono mostrati i risultati di un'ampia campagna sperimentale per la caratterizzazione meccanica di compositi con fibre naturali e la loro applicazione ad elementi strutturali in muratura, in diverse condizioni di carico applicato e geometrie murarie. Parole chiave: Fibre naturali – Compositi – FRCM - Massoneria
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Bernasconi, A., F. Cosmi, and D. Dreossi. "Analisi dell’anisotropia microstrutturale in materiali compositi rinforzati con fibre corte." Frattura ed Integrità Strutturale 2, no. 3 (March 22, 2008): 18–29. http://dx.doi.org/10.3221/igf-esis.03.03.

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Manauta, Jordi, Walter Devoto, and Angelo Putignano. "In & Out: i segreti della stratificazione dei materiali compositi." Dental Cadmos 82, no. 4 (April 2014): 270–73. http://dx.doi.org/10.1016/s0011-8524(14)70163-1.

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Saracinelli, Monaldo, Giuseppe Marchetti, Walter Devoto, and Angelo Putignano. "Uso razionale dei moderni compositi negli anteriori, anche con discromie gravi." Dental Cadmos 85, no. 10 (December 2017): 675. http://dx.doi.org/10.19256/d.cadmos.10.2017.10.

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Cartone, Alfredo, and Paolo Postiglione. "Le componenti principali pesate geograficamente per la definizione di indicatori compositi locali." RIVISTA DI ECONOMIA E STATISTICA DEL TERRITORIO, no. 1 (June 2016): 33–52. http://dx.doi.org/10.3280/rest2016-001002.

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Berrone, M., E. Crosetti, P. L. Tos, M. Pentenero, and G. Succo. "Fibular osteofasciocutaneous flap in computer-assisted mandibular reconstruction: technical aspects in oral malignancies." Acta Otorhinolaryngologica Italica 36, no. 6 (December 2016): 469–78. http://dx.doi.org/10.14639/0392-100x-1282.

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L’utilizzo della pianificazione virtuale in chirurgia testa e collo è in forte crescita. In letteratura, la validità del metodo dal punto di vista dell’acuratezza e l’utilità clinica sono stati ampiamente documentati, in modo particolare per il rimodellamento osseo del lembo. Al giorno d’oggi, l’aumentato utilizzo della programmazione virtuale in chirurgia oncologica testa-collo e, conseguentemente, la maggiore necessità di ricostruzioni sia ossee che dei tessuti molli, rendono importante realizzare il programma virtuale considerando non solo la ricostruzione ossea, ma anche tutti gli aspetti relativi alla ricostruzione dei tessuti molli con lembi compositi. Descriviamo nel seguente articolo il nostro approccio alla pianificazione virtuale nel caso di lembi compositi. Lo studio riporta sei pazienti consecutivi con malattia maligna programmati mediante ricostruzione mandibolare computer assistita e lembi osteo-fascio-cutanei di perone. In tutti i sei pazienti, la resezione e la ricostruzione sono state progettate concentrandosi sulla posizione dei vasi perforanti cutanei, al fine di programmare la posizione più corretta delle guide di taglio a livello del perone in funzione della posizione dei vasi perforanti stessi. La tecnica descritta ci ha permesso di programmare lembi osteo-fascio-cutanei di perone nella ricostruzione mandibolare computer assistita, con buona precisione della posizione del segmento osseo rispetto alla padella cutanea, importante per la ricostruzione dei tessuti molli. Nonostante il numero limitato di casi, i risultati preliminari dello studio suggeriscono che questo protocollo è utile nella programmazione virtuale. Sono necessarie ulteriori indagini.
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Beretta, S., A. Bernasconi, A. Pirondi, and F. Moroni. "Analisi basata sugli sforzi locali della resistenza a fatica di giunzioni incollate di materiali compositi." Frattura ed Integrità Strutturale 3, no. 9 (July 1, 2009): 145–52. http://dx.doi.org/10.3221/igf-esis.09.15.

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Scolavino, Salvatore. "Modifiche di forma mediante restauri adesivi diretti combinando compositi ad alta e bassa diffusione della luce." Dental Cadmos 90, no. 03 (February 2022): 239. http://dx.doi.org/10.19256/d.cadmos.03.2022.10.

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Luchetti, Alberto. "La traduzione, esigenza e possibilitŕ dell'opera." PSICOTERAPIA E SCIENZE UMANE, no. 2 (June 2010): 189–200. http://dx.doi.org/10.3280/pu2010-002003.

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Che la traduzione, altra professione impossibile, sia costruzione dell'originale č esemplarmente evidenziato dalla psicoanalisi, che interroga in modo peculiare il rapporto dell'uomo col linguaggio e le lingue. Freud, oltre a praticare la traduzione e a usarla insistentemente come metafora, arrivň a proporla come modello della memoria e del funzionamento psichico, dunque ipotizzando l'inconscio come intradotto e intraducibile, eppure incessantemente ritradotto. Alla maniera dei "ritratti compositi" o "immagini generiche" di Galton, la sovrapposizione delle diverse traduzioni dell'opera freudiana nelle diverse lingue, nella loro oscillazione tra etnocentrismo e "prova dello straniero", tra ricentramento e decentramento, contribuiscono a figurare concretamente l'astrazione dell'inconscio sessuale, la scoperta del volto eccentrico di ogni individualitŕ. In questo senso la traduzione costituirebbe non solo una esigenza ma altresě una possibilitŕ dell'opera freudiana.
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Dissertations / Theses on the topic "Compositi"

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MADAU, FRANCESCO. "Compositi autodiagnosticanti nanostrutturati." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2013. http://hdl.handle.net/2108/203237.

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Valorosi, Filippo. "Compositi lana-geopolimero: produzione e caratterizzazione." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/9900/.

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Lo scopo di questo lavoro sperimentale ha riguardato l’ottimizzazione del processo di produzione di materiali compositi ecocompatibili per pannellature con proprietà termoisolanti e resistenza al fuoco, già oggetto di brevetto CNR. Questi compositi sono ottenuti miscelando fibre di lana di scarto in una matrice geopolimerica. Le fibre di lana, a base di cheratina, vengono parzialmente attaccate dalle soluzioni alcaline portando al rilascio di ammoniaca e a una degradazione del materiale. Questo fenomeno, che si verifica in modo non sistematico, è tanto più marcato quanto maggiori sono le dimensioni dei manufatti prodotti, in quanto aumenta il tempo in cui le fibre di lana rimangono nell’ambiente acquoso alcalino. Il fattore di scala risulta quindi essere determinante. È stata pertanto investigata la degradazione delle fibre di lana in ambiente acquoso alcalino necessario alla sintesi della matrice geopolimerica. Sono stati anche valutati diversi trattamenti volti a velocizzare l’essiccamento del composito e fermare contestualmente il rilascio di ammoniaca, quali: aumento dei tempi e delle temperature di postcura, vacuum bagging e liofilizzazione (freeze drying).
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D'Angelo, Emanuele. "(Nano)-compositi avanzati a matrice epossidica." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7646/.

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I materiali (nano)compositi, unendo al loro interno le prestazioni dei loro componenti, che in alcuni casi possono addirittura agire sinergicamente sviluppando nuove proprietà non appartenenti alle singole fasi isolate, appaiono come una risposta ottimale alle nuove esigenze che richiedono materiali performanti dal punto di vista meccanico e sempre più dotati di funzionalità aggiuntive. È noto come l’uso di nanocariche consenta non solo di migliorare le proprietà meccaniche, ma di aggiungere proprietà funzionali di varia natura. In questo lavoro di tesi si sono quindi valutate due tipologie di nanocariche, grafene e organoclay (ritardante di fiamma), come modificatori di una matrice epossidica commerciale. La stessa matrice è stata utilizzata anche per produrre compositi contenenti fibra di carbonio riciclata da pirolisi, con la prospettiva futura di unire i processi e ottenere compositi da fibra di riciclo e matrice multifunzionale.
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RUSCITO, GIOVANNI. "Materiali compositi a matrice polimerica autodiagnosticanti." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1226.

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L’attività di ricerca svolta è stata focalizzata sullo studio e la realizzazione di Materiali Autodiagnosticanti: ovvero materiali con la duplice funzione strutturale e di sensore. I materiali scelti per questo scopo sono compositi a matrice polimerica, dato il loro vasto campo applicativo e la loro grande versatilità. Il materiale realizzato consta di due parti fondamentali: il rinforzo strutturale costituito da fibre di vetro in resina epossidica e l’elemento sensibile costituito da una fase elettricamente conduttrice in carbonio in forma di fibre lunghe unidirezionali o nanoparticelle o nanofibre disperse nella resina epossidica. I compositi ibridi, realizzati in forma di tondini mediante un processo di pultrusione manuale, sono costituiti dall’elemento sensibile interno coassialmente rivestito di vetroresina. In tutti i casi l’efficienza dell’autodiagnosi è stata valutata correlando la variazione di resistenza elettrica della fase conduttrice con il carico e/o la deformazione applicati all’intero composito. Per ciascun tipo di elemento sensibile sono stati indagati aspetti precisi: 1. nel caso degli elementi sensibili in fibra di carbonio unidirezionali ci si è particolarmente soffermati sull’influenza della quantità di vetro esterna sulle proprietà di autodiagnosi; 2. nei provini con elementi sensibili realizzati con nano-particelle e nanofibre di carbonio in resina epossidica si è indagato l’effetto della tipologia di particelle impiegate (area superficiale, dimensione, aspect ratio, ecc.) sulle proprietà di conducibilità elettrica e di autodiagnosi. I risultati dei sensori con fibra di carbonio hanno evidenziato che questo tipo di materiale non è particolarmente adatto ad una funzione di monitoraggio continuo della sollecitazione, bensì ha interessanti applicazioni quale “sensore di guardia” con comportamento tipo “on-off”. Ciò a causa del particolare meccanismo di conduzione che consente sempre un cospicuo passaggio di corrente fino alla rottura delle fibre di carbonio. La ricerca ha evidenziato che tale comportamento di guardia può essere influenzato dalla quantità di vetro che riveste l’elemento sensibile. In particolare, l’attivazione del segnale di guardia (resistenza elettrica pari ad infinito) può essere anticipato rispetto alla rottura finale del composito aumentando la quantità di vetro. I sensori realizzati con nanoparticelle di carbonio hanno invece mostrato grande capacità di monitoraggio in continuo, e ciò a causa del fatto che in questi sistemi la conducibilità elettrica è associata ad un modello percolativo. All’aumentare del carico (e quindi della deformazione) del materiale, le particelle conduttrici vengono progressivamente allontanate le une dalle altre consentendo di registrare un graduale e continuo aumento della resistenza elettrica. In questi sistemi, tuttavia, la natura, morfologia, dimensione, area superficiale, ecc. delle nano-particelle influenzando notevolmente la formazione del network percolativo, influenzano conseguentemente anche le proprietà di autodiagnosi. Le particelle ad elevata area superficiale hanno mostrato le migliori proprietà di autodiagnosi. Nel passaggio dalle nanoparticelle alle nano-fibre di carbonio non ha portato i miglioramenti attesti. Questo particolare sistema è stato indagato in quanto consente teoricamente di ottenere buona conducibilità elettrica con minore quantitativo di carica grazie all’elevato aspect ratio delle nanofibre, tuttavia la manifattura degli elementi sensibili è risultata estremamente complessa. Le nanofibre commerciali, infatti, vengono fornite in forma di aggregati micrometrici e che necessitano lunghe manipolazioni con solventi per essere disaggregati. Tali operazioni, possibili con limitate quantità di materiale, sono invece molto difficoltose e delicate quando applicate a sistemi più grandi quali la pultrusione impiegata per realizzare i materiali di questa sperimentazione. I sensori ottenuti in nano fibra di carbonio, frutto di un compromesso tra il livello di dispersione delle nanofibre nella resina e la processabilità, hanno dimostrando proprietà di autodiagnosi molto simili a quelle delle particelle di carbonio con area superficiale bassa, assai poco soddisfacenti. I materiali risultati più idonei alle funzioni di autodiagnosi, ovvero quelli con elemento sensibile in nanoparticelle di carbonio ad elevata area superficiale, sono stati poi provati in condizioni pratiche di esercizio, quali rinforzi strutturali in travi di calcestruzzo. I risultati hanno mostrato che i materiali realizzati conservano le proprietà di autodiagnosi sotto carico anche se inseriti in sistemi massivi come il calcestruzzo e che, inoltre, grazie alla loro sensibilità è stato possibile monitorarne anche la fase di presa ed indurimento.
The research carried out was focused on the study and production of Composite Smart Material: materials with the dual function: structural and sensor. The materials chosen for this purpose are polymer matrix composites, due to their vast application field and their versatility. The material produced consists of two basic parts: the structural reinforcement consists of glass fibers in epoxy resin and the sensible element consists of a phase-sensitive electrically conductive carbon in the form of unidirectional long fibers or nanoparticles or nanofibers dispersed in epoxy resin. The hybrid composite, realized in the form of rods by a process of pultrusion manual, consisting of the element sensitive internal coaxially coated fiberglass. In all cases the efficiency of smart properties was assessed by correlating the change in electrical resistance of the phase conductor with the load and / or deformation applied to the entire composite. For each type of sensor element have been investigated specific aspects: 1. in the case of sensitive elements in carbon fiber unidirectional one is particularly dwelt on the influence of the amount of exterior glass on the properties of self-diagnosis; 2. in samples with sensitive elements made of nano-particles and carbon nanofibers in epoxy resin was investigated the effect of the type of particles used (surface area, size, aspect ratio, etc..) on the properties of electrical conductivity and self-diagnosis. The results of the sensors with carbon fiber have shown that this type of material is not particularly suitable for continuous monitoring function of the stress, but has interesting applications such as "Sensor Guard" behavior such as "on-off". This is because of the particular mechanism that allows always run a large current passing through rupture of carbon fibers. Research has shown that this behavior may be influenced guard by the amount of glass that covers the sensing element. In particular, the activation of the signal call (electrical resistance equal to infinity) may be faster than the final break of the composite by increasing the amount of glass. The sensors made of carbon nanoparticles have shown great ability but continuous monitoring owing to the fact that in these systems, the electrical conductivity is associated with a percolation model. Increasing load (ie deformation) of the material, the conductive particles are gradually removed from each other allowing you to record a gradual and continuous increase in electrical resistance. In these systems, however, the nature, morphology, size, surface area, etc.. of nano-particles significantly influence the formation of the percolation network, thus also affecting the properties of self-diagnosis. Particles with high surface area showed the best properties of self-diagnosis. In the transition from nanoparticles to nano-carbon fibers did not lead to improvements attests. This particular system has been investigated theoretically since it allows to obtain good electrical conductivity with less quantity of charge thanks to the high aspect ratio of nanofibers, but the manufacturing of the sensing elements was extremely complex. The nanofibers trade, in fact, is provided in the form of aggregated micro and requiring lengthy manipulations with solvents to be broken. Such operations, possibly with small amounts of material, are very difficult and sensitive when applied to larger systems such as pultrusion designed to produce the materials of this trial. The sensors obtained in nano carbon fiber, a compromise between the degree of dispersion of nanofibers in the resin and processability, showed properties very similar to the self of carbon particles with low surface area, not very satisfactory. The materials are more appropriate to the functions of self-diagnosis or those with sensitive element in nanoparticles of carbon with high surface area, were then tested in practical conditions of operation, such as structural reinforcement in concrete beams. The results showed that the materials remain the property of self-made load even if incorporated into systems such as the massive concrete and that, furthermore, due to their sensitivity has been possible to also monitor the stage setting and hardening.
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Toni, Federica. "Invecchiamento di materiali compositi: effetto del tempo." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Il presente elaborato propone lo studio degli effetti dell'invecchiamento termo-ossidativo sulla resistenza interlaminare e sulla temperatura di transizione vetrosa di materiali compositi a matrice polimerica rinforzata da fibre di carbonio (CFRP), in particolare ricerca una correlazione fra la perdita di peso e la perdita delle proprietà meccaniche. I materiali analizzati sono di tre tipi: uno pre-impregnato e due ottenuti per infusione di resina (RTM), con stessa forma ma diversa formulazione della resina epossidica. I test sono stati effettuati seguendo gli standard ASTM. I provini sono stati invecchiati a diverse temperature e per diversi tempi, rispettivamente a 180°C, 200°C, 220°C, 240°C e 24, 72 e 168 ore. I risultati dei test mostrano che la perdita di peso dovuta al processo di invecchiamento non influisce in modo decisivo sulla resistenza a taglio interlaminare se non alle alte temperature vicine e al di sopra della temperatura di transizione vetrosa e ad elevati tempi, e che quindi a temperature più basse la degradazione meccanica è dominata da altri fenomeni di tipo fisico e chimico.
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Ciccone, Francesco. "Analisi del taglio interlaminare in materiali compositi." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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Nel settore aeronautico il materiale più largamente utilizzato è stato l’alluminio; la ricerca scientifica ha prodotto molti test riguardo a questo particolare metallo e le sue proprietà risultano largamente note. Dagli anni 70 però è entrata in scena la fibra di carbonio, risultando un materiale di utilizzo molto vantaggioso sia per la sua leggerezza, fondamentale per il peso finale degli aerei, sia per le sue proprietà meccaniche, che gli consentono di avere enormi resistenze ai carichi applicati. Ovviamente gli studi condotti sull’alluminio sono stati fatti riguardo la trazione. All’inizio anche i compositi sono stati studiati a trazione, producendo però un'enorme quantità di dati che purtroppo si sono verificati poco interessanti, al contrario invece degli studi condotti sulla compressione. Questo perché, come si è capito in seguito, i materiali compositi lavorano in maniera differente dall’alluminio e dagli altri metalli. L’obbiettivo del seguente lavoro è proprio quello di studiare il taglio interlaminare prodotto dalla compressione su materiale in fibra di carbonio. Più nel dettaglio, questa tesi segue un precedente studio condotto dalla dottoressa Monica Damiani, dove i provini in fibra di carbonio sono stati testati analizzando il loro comportamento a fatica. I risultati hanno quindi prodotto la curva S-N o anche detta di Woehler. Analizzando tale curva però, si è riscontrato un dubbio riguardo la precoce rottura di alcuni provini testati applicando il 70% del carico massimo. Tale rottura è avvenuta anche prima di quella dei provini testati all’80% del carico massimo. Quindi lo studio seguente è stato quello di riproporre il test a fatica su altri provini dello stesso materiale, applicando anche questa volta il 70% del carico. Successivamente si sono analizzati i dati ricavati, facendo un confronto con quelli precedenti, cercando di dare possibili soluzioni al problema.
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Cuoghi, Valentina. "Studio di catalisi termoattivate per compositi poliuretanici." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4388/.

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One of the key processing parameters in thermoset composites manufacturing is to have an optimum balance between open time and cure time. Long open times followed with a fast cure profile (also referred as snap cure or “hockey stick” shaped profiles) are required on applications like Pultrusion, Filament Winding, Resin Transfer Molding (RTM) and Infusion. In this work, several factors affecting the reactivity of a base line polyurethane formulation were studied. The addition of different components such as internal mold release agents, cross-linker, polyols having different molecular structure and isocyanates having different functionality were studied. A literature search was conducted to identify the main catalyst packages existing in the market. The reactivity of catalyst based on tertiary amines, orgamometallic salts, and co-catalyst of amine-organometallic complexes was characterized. Addition of quelants agents such as thioglycerol and acetyl acetone to delay the catalyst activity were also considered. As a consequence of this work a vast reactivity map was generated. This should guide the formulation designer in future product generations for the further development of the mentioned applications. Recommendations on measurements systems and further areas of exploration are also given.
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Bastardi, Tommaso. "Valutazione della resistenza all’impatto di laminati compositi." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18572/.

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Nel presente lavoro di tesi è stato studiato il comportamento all’impatto di laminati compositi di varia natura, valutando il danneggiamento ad impatti a bassa velocità. Il comportamento dei diversi campioni è stato osservato prendendo come riferimento un laminato in fibra di carbonio e resina epossidica. Al fine di studiare e migliorare la risposta dei materiali a questo tipo di sollecitazioni sono stati utilizzati diversi approcci: introduzione di strati eterogenei di natura differente e uso di tessuti ibridi (fibre di carbonio e fibre polimeriche). I campioni sono stati quindi sottoposti ad impatti a diversa energia, con lo scopo di valutare l’energia assorbita e la loro deformazione. I provini danneggiati sono stati quindi sottoposti ad analisi di caratterizzazione microscopica, termica e meccanica.
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Mancini, Nicola. "Sviluppo di laminati compositi sensorizzati tramite membrane nanofibrose." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18124/.

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Tra le principali problematiche che affliggono i laminati compositi vi è il cedimento per delaminazione, ovvero il distacco delle lamine costituenti, a seguito delle sollecitazioni meccaniche cui il componente è sottoposto durante la vita d’uso. È di estrema importanza che tale effetto negativo, oltre ad essere minimizzato, venga opportunamente rilevato al fine di intervenire prima che avvenga il cedimento strutturale, evitando danni a persone e cose. Quindi la ricerca di sistemi per il monitoraggio dell’integrità strutturale (Structural Health Monitoring, SHM) è di grande interesse industriale. L’obiettivo del presente lavoro di tesi riguarda l’applicazione di nuovi materiali in laminati compositi con lo scopo di rendere possibile il monitoraggio dell’integrità strutturale del materiale.
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Pampanini, Marco. "Caratterizzazione di materiali compositi rinforzati con fibra naturale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/22101/.

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Questa tesi si pone l'obiettivo di studiare e caratterizzare materiali compositi rinforzati con fibra di lino, con particolare attenzione rivolta al confronto tra due diversi tessuti pre-impregnati in resina epossidica. Questi materiali stanno avendo una grande importanza in settori come quello automotive, dove la loro leggerezza e le proprietà meccaniche discrete si stanno facendo spazio tra le ormai usatissime fibre di carbonio e di vetro. Inoltre, il fattore principale per cui molte organizzazioni sportive e produttori di veicoli sono interessati a questi materiali, è sicuramente quello ambientale, vista la sostenibilità della catena di produzione del lino. Approfondita questa tematica, vengono presentate le normative ASTM utilizzate per la caratterizzazione del materiale composito, ovvero test di trazione, taglio in piano, compressione e taglio interlaminare ILSS; queste prove sono essenziali per ottenere informazioni sulle proprietà meccaniche necessarie in fase di progettazione e per determinare, quindi, il campo di applicazione del materiale. Viene, poi, presentato il ciclo di produzione dei provini oggetto dei test, sono esposti i relativi risultati e sono svolte analisi calorimetriche e termogravimetriche, con lo scopo principale di ottenere la temperatura di transizione vetrosa del composito reticolato, in seguito ad un ciclo di cura in autoclave. Infine, viene esposto il confronto tra i risultati ottenuti, in seguito alle prove, dai due materiali presi in esame.
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Books on the topic "Compositi"

1

Rossella, Bedini, ed. Valutazione delle prestazioni meccaniche ad usura di due materiali compositi innovativi. Roma: Istituto superiore di sanità, 1998.

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Fonseca, Giancarlo. Materiali compositi: Stato dell'arte e prospettive di sviluppo della tecnologia della pultrusione. Napoli: Edizioni scientifiche italiane, 1994.

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Arduini, Marco. Il rinforzo con materiali compositi fibrosi FRP per strutture in cemento armato, muratura, legno. Santarcangelo di Romagna (RN): Maggioli, 2010.

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Fiber reinforced plasctics [sic]: Utilizzo dei materiali compositi a matrice polimerica in edilizia civile. Firenze: Alinea, 1998.

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Rossella, Bedini, ed. Studio in vitro delle prestazioni meccaniche dell'interfaccia tra materiali compositi dentari e leghe metalliche preziose. Roma: Istituto superiore di sanità, 2000.

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Zaccomer, Gian Pietro. L'analisi territoriale socio-economica in ambito paesaggistico: Gli indicatori compositi per la zonizzazione territoriale del Friuli Venezia Giulia. Udine: Forum, 2018.

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Morelli, Serena. Périphéries financières angevines: Institutions et pratiques de l'administration de territoires composites (XIIIe-XVe siècle) = Periferie finanziarie angioine : istituzioni e pratiche di governo su territori compositi (sec. XIII-XV). [Rome]: École française de Rome, 2018.

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author, Gupta A. C., ed. Polymer composites. London: New Academic Science, 2019.

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(Firm), Knovel, ed. Composite materials handbook: Metal matrix composites. [Washington, D.C.?]: U.S. Department of Defense, 2002.

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1939-, Vigo Tyrone L., and Kinzig Barbara J, eds. Composite applications: The role of matrix, fiber, and interface. New York, N.Y: VCH, 1992.

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Book chapters on the topic "Compositi"

1

Piergiovanni, Luciano, and Sara Limbo. "Materiali e imballaggi flessibili compositi." In Food, 259–74. Milano: Springer Milan, 2010. http://dx.doi.org/10.1007/978-88-470-1457-2_10.

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Panin, Sergey V., Lyudmila A. Kornienko, Nguyen Duc Anh, Vladislav O. Alexenko, Dmitry G. Buslovich, and Svetlana A. Bochkareva. "Three-Component Wear-Resistant PEEK-Based Composites Filled with PTFE and MoS2: Composition Optimization, Structure Homogenization, and Self-lubricating Effect." In Springer Tracts in Mechanical Engineering, 275–99. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60124-9_13.

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AbstractThe aim of this work was to design and optimize compositions of three-component composites based on polyetheretherketone (PEEK) with enhanced tribological and mechanical properties. Initially, two-component PEEK-based composites loaded with molybdenum disulfide (MoS2) and polytetrafluoroethylene (PTFE) were investigated. It was shown that an increase in dry friction mode tribological characteristics in metal-polymer and ceramic-polymer tribological contacts was attained by loading with lubricant fluoroplastic particles. In addition, molybdenum disulfide homogenized permolecular structure and improved matrix strength properties. After that, a methodology for identifying composition of multicomponent PEEK-based composites having prescribed properties which based on a limited amount of experimental data was proposed and implemented. It was shown that wear rate of the “PEEK + 10% PTFE + 0.5% MoS2” composite decreased by 39 times when tested on the metal counterpart, and 15 times on the ceramic one compared with neat PEEK. However, in absolute terms, wear rate of the three-component composite on the metal counterpart was 1.5 times higher than on the ceramic one. A three-fold increase in wear resistance during friction on both the metal and ceramic counterparts was achieved for the “PEEK + 10% PTFE + 0.5% MoS2” three-component composite compared with the “PEEK + 10% PTFE”. Simultaneous loading with two types of fillers slightly deteriorated the polymer composite structure compared with neat PEEK. However, wear rate was many times reduced due to facilitation of transfer film formation. For this reason, there was no microabrasive wear on both metal and ceramic counterpart surfaces.
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Molnár, K., and L. M. Vas. "Electrospun Composite Nanofibers and Polymer Composites." In Synthetic Polymer-Polymer Composites, 301–49. München: Carl Hanser Verlag GmbH & Co. KG, 2012. http://dx.doi.org/10.3139/9781569905258.010.

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Barker, Allen V. "Composition and Uses of Compost." In ACS Symposium Series, 140–62. Washington, DC: American Chemical Society, 1997. http://dx.doi.org/10.1021/bk-1997-0668.ch010.

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Isaac Premkumar, I. J., V. Vijayan, K. Rajaguru, and B. Suresh Kumar. "Non-destructive Evaluation for Composite Aluminium Composites." In Lecture Notes in Mechanical Engineering, 711–16. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4739-3_62.

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Murr, Lawrence E. "Examples of Natural Composites and Composite Structures." In Handbook of Materials Structures, Properties, Processing and Performance, 425–49. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-01815-7_25.

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Murr, Lawrence E. "Examples of Natural Composites and Composite Structures." In Handbook of Materials Structures, Properties, Processing and Performance, 1–21. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-01905-5_25-1.

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Diani, Marco, Abdelrahman H. Abdalla, Claudio Luis de Melo Pereira, and Marcello Colledani. "Impact of Policy Actions on the Deployment of the Circular Value-Chain for Composites." In Systemic Circular Economy Solutions for Fiber Reinforced Composites, 445–74. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-22352-5_21.

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AbstractThe effect of legislation on composites recycling can be both a driving force, such as in the case of End-of-Life Vehicle legislation, that is making it mandatory to reuse the materials used in vehicle manufacturing, or a boundary, increasing the burden to manufacturers reusing composite materials. As a consequence, a deep study on the impact of policies on the reuse of composites is fundamental to promote those actions boosting the deployment of circular value-chains. In this Chapter, a model based on System Dynamics theory, representing the entire industrial environment of composite materials, has been developed, leading to a prioritization of most impacting legislations, providing conclusions and recommendations derived from data.
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Skrtic, Drago, S. Y. Lee, Joseph M. Antonucci, and D. W. Liu. "Amorphous Calcium Phosphate Based Polymeric Composites: Effects of Polymer Composition and Filler's Particle Size on Composite Properties." In Bioceramics 17, 737–40. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-961-x.737.

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Libonati, F. "Bio-inspired Composites: Using Nature to Tackle Composite Limitations." In Advanced Engineering Materials and Modeling, 165–90. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119242567.ch5.

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Conference papers on the topic "Compositi"

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Lu, Lu, Shan Hu, and Yayue Pan. "3D Printed Particle-Polymer Composites With Acoustically Localized Particle Distribution for Thermal Management Applications." In ASME 2018 13th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/msec2018-6643.

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The particle-polymer composite can perform multiple functionalities according to particle property, local particle distribution, and alignment. This paper shows thermal management applications of in situ manipulations of particle dispersion patterns within a 3D printed polymeric composite architecture. A 3D printed particle-polymer composite with enhanced thermal conductive properties was developed. Composite structures containing 30-micron-sized aluminum particles embedded in the acrylate polymer were produced using a novel acoustic field assisted projection based Stereolithography process. Thermal properties of the pure polymer and prepared uniform composite with 2.75 wt% particle were characterized by using the transient hot bridge technique. To investigate the effect of material composition and particle distribution pattern on composite thermal behavior, heat sinks were designed and fabricated with the pure polymer, homogeneous composite with particles uniformly distributed in the polymer matrix, and composite with patterned particles for comparison. Infrared thermal imaging was performed on the 3D printed objects. The homogeneous composites displayed slight enhancement in thermal conductivity. A significant improvement of heat dissipation speed was observed for the patterned composite, due to a densely interconnected aluminum aggregate network. To further improve the thermal property of the patterned composite, varying layer thicknesses were tested. The developed patterned composites with superior performance compared to the inherent polymer material and homogeneous composites can be used for fabricating thermal management applications in electronic and fluidic devices.
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Morscher, Gregory N., and Vijay V. Pujar. "Melt-Infiltrated SiC Composites for Gas Turbine Engine Applications." In ASME Turbo Expo 2004: Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53196.

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SiC-SiC ceramic matrix composites (CMCs) manufactured by the melt-infiltration (MI) process are leading candidates for many hot-section turbine engine components. A collaborative program between Goodrich Corporation and NASA-Glenn Research Center is aimed at determining and optimizing woven SiC/SiC CMC performance and reliability. A variety of composites with different fiber types, interphases and matrix composition have been fabricated and evaluated. Particular focus of this program is on the development of interphase systems that will result in improved intermediate temperature stressed-oxidation properties of this composite system. The effect of the different composite variations on composite properties is discussed and, where appropriate, comparisons made to properties that have been generated under NASA’s Ultra Efficient Engine Technology (UEET) Program.
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Rizvi, Reza R., Jae K. Kim, and Hani E. Naguib. "Processing and MWNT Composition Effects on the Thermal, Electrical and Mechanical Properties of PLA-MWNT Composites." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-11314.

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This paper investigates the processing and its effects and the effect of multiwall carbon nanotube (MWNT) composition on the thermal, electrical and mechanical properties of polylactide (PLA)-MWNT composites. The composite films were prepared by a solvent casting process using two solvents, chloroform and 1,4-dioxane. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be more improved when 1,4-dioxane was used as the solvent as compared to chloroform. The thermal characteristics of the composites were examined on Differential Scanning Calorimetry and Thermo-gravimetric Analysis. Composites prepared using 1,4-dioxane had greater improvements in composite decomposition temperature, glass transition temperature and displayed faster crystallization kinetics. The mechanical properties of the composites were tested in uniaxial tension. Composites prepared using chloroform had a lower modulus than composites prepared using 1,4-dioxane. The electrical AC conductivity of the composites was measured over a broad frequency spectrum. Composites prepared using 1,4-dioxane displayed electrical percolation at 0.5 wt.% MWNT in PLA while percolation was absent in 0.5 wt.% MWNT composites prepared using chloroform.
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Hsiao, Min-Chien, Shu-Hang Liao, Ming-Yu Yen, Chen-Chi M. Ma, Shuo-Jen Lee, Yu-Feng Lin, and Chih-Hung Hung. "Electrical and Thermal Conductivities of Novel Metal Mesh Hybrid Polymer Composite Bipolar Plates for Proton Exchange Membrane Fuel Cells." In ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85134.

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Novel metal mesh hybrid polymer composite bipolar plates for proton exchange membrane fuel cells (PEMFCs) have been prepared via inserting a copper or alumina mesh in polymer composites. The composition of polymer composites consisted of 70 wt% graphite powder and 0–2 wt% modified multi-walled carbon nanotubes (m-MWCNTs). Results indicated that the inplane electrical conductivity of m-MWCNTs/polymer composite bipolar plates increased from 156 S cm−1 (0 wt% MWCNT) to 643 Scm−1 (with 1 wt% MWCNT) (D.O.E target > 100 S cm−1). The bulk thermal conductivities of the copper and aluminum mesh hybrid polymer composite bipolar plates increased from 27.2 W m−1 K−1 to 30.0 W m−1 K−1 and 30.4 W m−1 K−1, respectively. Furthermore, the current and power densities of a single fuel cell using copper or alumina mesh hybrid polymer composite bipolar plates are more stable than that of using neat polymer composite bipolar plates, especially in the ohmic overpotential region of the polarization curves of single fuel cell tests. The overall performance confirms that the metal mesh hybrid polymer composite bipolar plates prepared in this study are promising for PEMFC application.
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Idrisi, Amir Hussain, and Abdel-Hamid Ismail Mourad. "Fabrication and Wear Analysis of Aluminium Matrix Composite Reinforced by SiC Micro and Nano Particles." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65459.

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Metal matrix composites (MMCs) constitute an important class of weight-efficient structural material which empowering every field of engineering applications. Aluminium based metal matrix composites contains potential for high specific strength and advanced structural applications, as well as good elevated temperature resistance along with light weight application. However, need for improved tribological performance has led to the fabrication of newer variants of the composite. In the present work, aluminium based metal matrix composite (MMCs) developed through stir casting route by reinforcing different weight percentage of SiC micro (5% and 10%) and nano (1% and 2%) particles. In this research, 5083 aluminium alloy is used as matrix phase due its broad range of industrial applications. Wear behaviour of the developed aluminium matrix composite (AMC) was investigated under different conditions of applied load, operation time and speed. The analysis carried out at room temperature for three different loads (10N, 20N, and 30N) with varying four different operation times (30 mins, 60 mins, 90 mins, and 120 mins). The speed was kept constant at 1450 rpm during all experiments. The results of all considered composites are investigated and the composite with 2% SiC nano reinforcement is identified as a superior among all other composition for tribological applications point of view. Also the developed aluminium matrix composites have potential applications in many industries such as pressure vessels, pipe fittings, boat hulls, gears and pistons.
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Widdowson, Denise, Paris von Lockette, Anil Erol, and Manuel A. Rodriguez. "A Computational Framework for Predicting Properties From Multifield Processing Conditions in Polymer Matrix Composites." In ASME 2020 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/smasis2020-2390.

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Abstract Composites can be tailored to specific applications by adjusting process variables. These variables include those related to composition, such as volume fraction of the constituents and those associated with processing methods, methods that can affect composite topology. In the case of particle matrix composites, orientation of the inclusions affects the resulting composite properties, particularly so in instances where the particles can be oriented and arranged into structures. In this work, we study the effects of coupled electric and magnetic field processing with externally applied fields on those structures, and consequently on the resulting material properties that arise. The ability to vary these processing conditions with the goal of generating microstructures that yield target material properties adds an additional level of control to the design of composite material properties. Moreover, while analytical models allow for the prediction of resulting composite properties from constituents and composite topology, these models do not build upward from process variables to make these predictions. This work couples simulation of the formation of microscale architectures, which result from coupled electric and magnetic field processing of particulate filled polymer matrix composites, with finite element analysis of those structures to provide a direct and explicit linkages between process, structure, and properties. This work demonstrates the utility of these method as a tool for determining composite properties from constituent and processing parameters. Initial particle dynamics simulation incorporating electromagnetic responses between particles and between the particles and the applied fields, including dielectrophoresis, are used to stochastically generate representative volume elements for a given set of process variables. Next, these RVEs are analyzed as periodic structures using FEA yielding bulk material properties. The results are shown to converge for simulation size and discretization, validating the RVE as an appropriate representation of the composite volume. Calculated material properties are compared to traditional effective medium theory models. Simulations allow for mapping of composite properties with respect to not only composition, but also fundamentally from processing simulations that yield varying particle configurations, a step not present in traditional or more modern effective medium theories such as the Halpin Tsai or double-inclusion theories.
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Wang, LiQin, JianWei Sun, and Le Gu. "Friction and Wear Behavior of Polyetherimide(PEI) Filled With Polytetrafluoroethylene(PTFE)." In STLE/ASME 2010 International Joint Tribology Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ijtc2010-41094.

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The tribological performance of Polyetherimide (PEI) composites filled with different Polytetrafluoroethylene (PTFE) content was comparatively evaluated on MM-200 test rig in block-on-ring configuration under dry friction condition. The microstructures of worn surfaces, fractured surfaces and wear mechanisms of the PEI composite were examined under scanning electron microscope (SEM). The variations of elastic modulus and surface hardness with variation in composition were also investigated. The results showed that under conditions of dry friction the PTFE can lower the friction coefficient and reduce wear of the PEI composites. When filled with 10 wt. % PTFE, the composite had the lowest wear rate. For PEI filled with 5wt. % PTFE the friction coefficient was about 0.3 and remained comparatively stable with increase of the PTFE content.
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Abdel Hamid, Dalia, Amal Esawi, Inas Sami, and Randa Elsalawy. "Characterization of Nano- and Micro-Filled Resin Composites Used as Dental Restorative Materials." In ASME 2008 2nd Multifunctional Nanocomposites and Nanomaterials International Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/mn2008-47053.

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Adhesively-bonded resin composites have the advantage of conserving sound tooth structure with the potential for tooth reinforcement, while at the same time providing an aesthetically acceptable restoration. However, no composite material has been able to meet both the functional needs of posterior restorations and the superior aesthetics required for anterior restoration. In an attempt to develop a dental resin composite that had the mechanical strength of hybrid composite materials and the superior polish and gloss retention associated with microfilled materials, nanofilled resin composites have been introduced in the market. Although nanofillers are the most popular fillers utilized in current visible light-activated dental resin composites and are claimed to be the solution for the most challenging material limitations as a universal restorative material, the mechanisms by which these fillers influence the resin composite properties are not well explained. In this study, some physical and mechanical properties of a nanofilled resin composite containing 60 vol. % zirconia and silica fillers were evaluated and compared to those of a microhybrid resin composite of the same composition. The nanofilled resin composite was found to have equivalent polymerization shrinkage and depth of cure to the microhybrid material but a slightly lower degree of conversion and density. Regarding mechanical behaviour, although the nanocomposite was found to exhibit significantly higher wear resistance, and equivalent flexural strength, its indentation modulus and nanohardness were slightly lower. Field-emission scanning electron microscopy (FE-SEM) analysis was conducted in order to evaluate the microstructure and to obtain a better understanding of the effect of the nanofillers on the behaviour of the nanocomposite.
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Petrach, Elaine, Ismat Abu-Isa, and Xia Wang. "Improvement of Mechanical Properties of Elastomer-Plastic Conductive Composites for Bipolar Plates in Proton Exchange Membrane Fuel Cells." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33071.

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Bipolar plates account for about 80% of the fuel cell stack weight. The use of low density and high strength conductive composites for making bipolar plates will result in a lighter and more compact fuel cell stack assembly. Light weight composites were developed based on a two component elastomeric silicone RTV matrix. However, two shortcomings of this composite material are low mechanical strength and relatively high permeability to gases. The purpose of this paper is to develop a new composite material which will overcome high permeability and low strength issues through the use of elastomer-plastic blends as the composite matrix. The elastomer-plastic blends consist of vinyl ester with either urethane elastomer or ethylene-propylene-diene (EPDM) rubber. The chosen elastomers have higher tensile strength and lower gas permeability than silicone rubber. The elastomers will be blended with vinyl ester thermoset plastic to further enhance these characteristics. Synergistic conductive filler system developed in previous work will be used for the new composites to make them conductive. Compatibility of blends ranging in concentration from pure plastic to pure elastomeric composition will be presented along with in-plane electrical resistivity and mechanical properties.
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Zantout, Alan, and Olesya I. Zhupanska. "Electrical Characterization of Carbon Fiber Polymer Matrix Composites." In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-10423.

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This paper studies the response of carbon fiber polymer matrix composites subjected to DC electric currents. We have developed a new fully instrumented experimental setup that enables one to measure electric field characteristics (amperage, voltage, resistance) and temperature at the surface of the electrified composites in real time. The experimental procedure ensured a low contact resistance between the composite and electrodes, high uniformity in the density of the applied electric current, and low resistance heating. An extensive experimental study on the electrical characterization of carbon fiber polymer composites of different composition, ply sequence, thickness, etc. was conducted. The effect of the resistance heating was carefully analyzed through experimental analysis as well as the finite element modeling.
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Reports on the topic "Compositi"

1

Hoitink, Harry A. J., Yitzhak Hadar, Laurence V. Madden, and Yona Chen. Sustained Suppression of Pythium Diseases: Interactions between Compost Maturity and Nutritional Requirements of Biocontrol Agents. United States Department of Agriculture, June 1993. http://dx.doi.org/10.32747/1993.7568755.bard.

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Several procedures were developed that predict maturity (stability) of composts prepared from municipal solid wastes (MSW). A respirometry procedure, based O2 uptake by compost, predicted (R2=0.90) the growth response of ryegrass in composts and an acceptable level of maturity. Spectroscopic methods (CPMAS13-NMR and DRIFT spectroscopy) showed that the stabilizing compost contained increasing levels of aromatic structures. All procedures predicted acceptable plant growth after approximately 110 days of composting. MSW compost suppressed diseases caused by a broad spectrum of plant pathogens including Rhizoctonia solani, Pythium aphanidermatum and Fusarium oxysporum. A strain of Pantoea agglomerans was identified that caused lysis of hyphae of R. solani. Evidence was obtained, suggesting that thermophilic biocontrol agents also might play a role in suppression. 13C-NMR spectra revealed that the longevity of the suppressive effect against Pythium root rot was determined by the concentration of readily biodegradable carbohydrate in the substrate, mostly present as cellulose. Bacterial species capable of inducing biocontrol were replaced by those not effective as suppression was lost. The rate of uptake of 14C-acetate into microbial biomass in the conducive substrate was not significantly different from that in the suppressive substrate although specific activity was higher. The suppressive composts induced systemic acquired resistance in cucumjber roots to Pythium root rot and to anthracnose in the foliage. Composts also increased peroxidase activity in plants by the conducive substrate did not have these effects. In summary, the composition of the organic fraction determined bacterial species composition and activity in the substrate, which in turn regulated plant gene expression relative to biological control.
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Hoitink, Harry A. J., Yitzhak Hadar, Laurence V. Madden, and Yona Chen. Sustained Suppression of Pythium Diseases: Interactions between Compost Maturity and Nutritional Requirements of Biocontrol Agents. United States Department of Agriculture, June 1993. http://dx.doi.org/10.32747/1993.7568746.bard.

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Several procedures were developed that predict maturity (stability) of composts prepared from municipal solid wastes (MSW). A respirometry procedure, based O2 uptake by compost, predicted (R2=0.90) the growth response of ryegrass in composts and an acceptable level of maturity. Spectroscopic methods (CPMAS13-NMR and DRIFT spectroscopy) showed that the stabilizing compost contained increasing levels of aromatic structures. All procedures predicted acceptable plant growth after approximately 110 days of composting. MSW compost suppressed diseases caused by a broad spectrum of plant pathogens including Rhizoctonia solani, Pythium aphanidermatum and Fusarium oxysporum. A strain of Pantoea agglomerans was identified that caused lysis of hyphae of R. solani. Evidence was obtained, suggesting that thermophilic biocontrol agents also might play a role in suppression. 13C-NMR spectra revealed that the longevity of the suppressive effect against Pythium root rot was determined by the concentration of readily biodegradable carbohydrate in the substrate, mostly present as cellulose. Bacterial species capable of inducing biocontrol were replaced by those not effective as suppression was lost. The rate of uptake of 14C-acetate into microbial biomass in the conducive substrate was not significantly different from that in the suppressive substrate although specific activity was higher. The suppressive composts induced systemic acquired resistance in cucumjber roots to Pythium root rot and to anthracnose in the foliage. Composts also increased peroxidase activity in plants by the conducive substrate did not have these effects. In summary, the composition of the organic fraction determined bacterial species composition and activity in the substrate, which in turn regulated plant gene expression relative to biological control.
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3

McCullough, Roy L., and Diane S. Kukich. Composites 2000: An International Symposium on Composite Materials. Fort Belvoir, VA: Defense Technical Information Center, June 2000. http://dx.doi.org/10.21236/ada384778.

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Dabizha, O. N., A. N. Khat’kova, N. V. Ryabova, and R. A. Filenko. Composition, structure and properties of composites рolyvinyl alcohol – natural zeolite. LJournal, 2017. http://dx.doi.org/10.18411/1680-0613-2017-17-4-534-541.

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Chattopadhyay, Aditi. Damage Precursor Detection in Polymer Matrix Composites Using Novel Smart Composite Particles. Fort Belvoir, VA: Defense Technical Information Center, September 2016. http://dx.doi.org/10.21236/ad1018261.

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Zhu, Y. T., J. A. Valdez, I. J. Beyerlain, M. G. Stout, S. Zhou, N. Shi, and T. C. Lowe. Innovative Composites Through Reinforcement Morphology Design - a Bone-Shaped-Short-Fiber Composite. Office of Scientific and Technical Information (OSTI), June 1999. http://dx.doi.org/10.2172/763899.

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Barnes, Eftihia, Jennifer Jefcoat, Erik Alberts, Hannah Peel, L. Mimum, J, Buchanan, Xin Guan, et al. Synthesis and characterization of biological nanomaterial/poly(vinylidene fluoride) composites. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/42132.

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The properties of composite materials are strongly influenced by both the physical and chemical properties of their individual constituents, as well as the interactions between them. For nanocomposites, the incorporation of nano-sized dopants inside a host material matrix can lead to significant improvements in mechanical strength, toughness, thermal or electrical conductivity, etc. In this work, the effect of cellulose nanofibrils on the structure and mechanical properties of cellulose nanofibril poly(vinylidene fluoride) (PVDF) composite films was investigated. Cellulose is one of the most abundant organic polymers with superior mechanical properties and readily functionalized surfaces. Under the current processing conditions, cellulose nanofibrils, as-received and 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) oxidized, alter the crystallinity and mechanical properties of the composite films while not inducing a crystalline phase transformation on the 𝛾 phase PVDF composites. Composite films obtained from hydrated cellulose nanofibrils remain in a majority 𝛾 phase, but also exhibit a small, yet detectable fraction of 𝛼 and ß PVDF phases.
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8

Minz, Dror, Eric Nelson, and Yitzhak Hadar. Ecology of seed-colonizing microbial communities: influence of soil and plant factors and implications for rhizosphere microbiology. United States Department of Agriculture, July 2008. http://dx.doi.org/10.32747/2008.7587728.bard.

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Original objectives: Our initial project objectives were to 1) Determine and compare the composition of seed-colonizing microbial communities on seeds, 2) Determine the dynamics of development of microbial communities on seeds, and 3) Determine and compare the composition of seed-colonizing microbial communities with the composition of those in the soil and rhizosphere of the plants. Revisions to objectives: Our initial work on this project was hampered by the presence of native Pythium species in the soils we were using (in the US), preventing us from getting accurate assessments of spermosphere microbial communities. In our initial work, we tried to get around this problem by focusing on water potentials that might reduce damage from native Pythium species. This also prompted some initial investigation of the oomycete communities associated seedlings in this soil. However, for this work to proceed in a way that would allow us to examine seed-colonizing communities on healthy plants, we needed to either physically treat soils or amend soils with composts to suppress damage from Pythium. In the end, we followed the compost amendment line of investigation, which took us away from our initial objectives, but led to interesting work focusing on seed-associated microbial communities and their functional significance to seed-infecting pathogens. Work done in Israel was using suppressive compost amended potting mix throughout the study and did not have such problems. Our work focused on the following objectives: 1) to determine whether different plant species support a microbial induced suppression of Pythium damping-off, 2) to determine whether compost microbes that colonize seeds during early stages of seed germination can adequately explain levels of damping-off suppression observed, 3) to characterize cucumber seed-colonizing microbial communities that give rise to the disease suppressive properties, 4) assess carbon competition between seed-colonizing microbes and Pythium sporangia as a means of explaining Pythium damping-off suppression. Background: Earlier work demonstrated that seed-colonizing microbes might explain Pythium suppression. Yet these seed-colonizing microbial communities have never been characterized and their functional significance to Pythium damping-off suppression is not known. Our work set out to confirm the disease suppressive properties of seed-colonizing microbes, to characterize communities, and begin to determine the mechanisms by which Pythium suppression occurs. Major Conclusions: Compost-induced suppression of Pythium damping-off of cucumber and wheat can be explained by the bacterial consortia colonizing seeds within 8 h of sowing. Suppression on pea was highly variable. Fungi and archaea play no role in disease suppression. Potentially significant bacterial taxa are those with affinities to Firmicutes, Actinobacteria, and Bacteroidetes. Current sequencing efforts are trying to resolve these taxa. Seed colonizing bacteria suppress Pythium by carbon competition, allowing sporangium germination by preventing the development of germ tubes. Presence of Pythium had a strong effect on microbial community on the seed.
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9

Ting, Jason. Quantitative evaluation of material composition of composites using x-ray energy-dispersive NDE technique. Office of Scientific and Technical Information (OSTI), September 1993. http://dx.doi.org/10.2172/10184977.

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10

Lucas, J., N. Yang, J. Stephens, and F. Greulich. The effect of reinforcement stability on composition redistribution in cast aluminum metal matrix composites. Office of Scientific and Technical Information (OSTI), May 1990. http://dx.doi.org/10.2172/6947086.

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