Letteratura scientifica selezionata sul tema "Glasses"

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Articoli di riviste sul tema "Glasses"

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Machinin, A. M., A. Awang, C. F. Pien e S. K. Ghoshal. "Tuning structural and wettability properties of glass using ellipsoidal TiO2 nanoparticles". Journal of Ovonic Research 18, n. 6 (21 novembre 2022): 731–38. http://dx.doi.org/10.15251/jor.2022.186.731.

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Self-cleaning glasses became demanding for various advanced applications due to their manifold advantages. In this view, some tellurite glasses containing TiO2 nanoparticles with varying concentrations were synthesized using the standard melt-quenching. These glasses were transparent with a reddish appearance. The HRTEM images of the glasses showed the presence of ellipsoidal TiO2 NPs with sizes ranging from 9−22 nm and 5−9 nm along the major and minor axis, respectively. The lattice fringe pattern of the selected TiO2 NPs confirmed their anatase structure with a lattice spacing of 0.36 nm. The observed reduction in the water contact angle from 67.5° to 43.0° of the glasses indicated their hydrophilic nature. The high work of adhesion (0.101− 0.126 N.m-1 ) of the glasses revealed the strong interfacial attractive force between water and glass. It was demonstrated that by adjusting the TiO2 NPs contents the hydrophilic traits of the glassed can be tailored, indicating the suitability for self-cleaning applications.
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Lusvardi, Gigliola, Francesca Sgarbi Stabellini e Roberta Salvatori. "P2O5-Free Cerium Containing Glasses: Bioactivity and Cytocompatibility Evaluation". Materials 12, n. 19 (8 ottobre 2019): 3267. http://dx.doi.org/10.3390/ma12193267.

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(1) Background: valuation of the bioactivity and cytocompatibility of P2O5-free and CeO2 doped glasses. (2) Methods: all glasses are based on the Kokubo (K) composition and prepared by a melting method. Doped glassed, K1.2, K3.6 and K5.3 contain 1.2, 3.6, and 5.3 mol% of CeO2. Bioactivity and cytotoxicity tests were carried out in simulated body fluid (SBF) solution and murine osteocyte (MLO-Y4) cell lines, respectively. Leaching of ions concentration in SBF was determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). The surface of the glasses were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. (3) Results: P2O5-free cerium doped glasses are proactive according to European directives. Cerium increases durability and retards, but does not inhibit, (Ca10(PO4)6(OH)2, HA) formation at higher cerium amounts (K3.6 and K5.3); however, cell proliferation increases with the amount of cerium especially evident for K5.3. (4) Conclusions: These results enforce the use of P2O5-free cerium doped bioactive glasses as a new class of biomaterials.
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Wójcik, N. A., S. Ali, A. Mielewczyk-Gryń e B. Jonson. "Two-step synthesis of niobium doped Na–Ca–(Mg)–P–Si–O glasses". Journal of Materials Science 56, n. 12 (25 gennaio 2021): 7613–25. http://dx.doi.org/10.1007/s10853-021-05781-w.

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AbstractNiobium doped biosolubility glasses in the Na–Ca–(Mg)–P–Si–O system were prepared by using an untypical two-step synthesis route. The parent glass was melted in air atmosphere at 1350 °C followed by re-melting the glass in Nb crucible with the addition of metallic Mg/Ca powder in the nitrogen atmosphere. The second melting step was carried out at 1450–1650 °C, using an induction furnace. The topography and structure of the obtained glasses were characterized by confocal microscopy, X-ray powder diffraction and infrared spectroscopic techniques. The chemical compositions were examined by energy-dispersive X-ray spectroscopy (EDS). The glasses were found to be of grayish color, X-ray amorphous and having network connectivity between ~ 2.5 and 2.7. The network connectivity of re-melted glasses was lower than the one of the parent glass. The glass structure consists of a highly disrupted silicate network of predominantly Q2 groups as well as isolated orthophosphate tetrahedra. The parent glass contains nanocrystallites consisted of apatitic PO43− groups. The re-melted glasses contain non-apatitic or amorphous calcium phosphates. The obtained glass transition temperatures range from 530 to 568 °C and exhibit higher values for glassed doped with Ca metal. These glasses have improved thermal stability as compared to reference bioglasses. The biosolubility test in phosphate buffered saline solution (PBS) confirms that the glasses have biosolubility properties and HAp formation on the surfaces was observed.
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Lu, An Xian, S. J. Liu, X. D. Tang e S. B. He. "Difference of Properties between Yb3+-Doped Silicate and Phosphate Laser Glasses". Advanced Materials Research 11-12 (febbraio 2006): 213–16. http://dx.doi.org/10.4028/www.scientific.net/amr.11-12.213.

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The Yb3+-doped silicate and phosphate laser glasses were prepared by using of traditional melt quenching technology, and the physical and spectral properties were investigated. The results show that the stimulated emission cross section and the fluorescence lifetime are 0.67×10-20cm2 and 1200μs for the silicate glass, and 0.75×10-20cm2 and 1000μs for the phosphate glass respectively. And silicate glass’s mechanical and thermal properties were better than that of phosphate glass. But Yb3+-doped phosphate glass has lower nonlinear refraction index n2. Both Yb3+-doped silicate and phosphate glasses are possible to be used as laser medium.
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B, Eraiah. "Electronic-Ionic Conductivity of Lithium- Vanado- Phosphate Glasses". Mapana - Journal of Sciences 14, n. 1 (7 luglio 2017): 9–14. http://dx.doi.org/10.12723/mjs.32.2.

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The new glassesof glass system x Li 2 O-50 V 2 O 5 -(50-x) P 2 O 5 were prepared by using conventional melt quenching method. The densities of these glasses have been measured by Archimedes method and corresponding molar volumes have also been calculated. The conductivity of these glasses was measured as a function of temperature and composition. The variations of conductivity versus temperature follow Arrehenius type relationship. Conductivity decreases with increasing Li 2 O content and increase with increasing temperature. The calculated activation energy decreases up to 15mol% of Li 2 O, it increases from 15mol% to 30 mol% of Li 2 O and again it suddenly drops at 40 mol% of Li 2 O. This may be due to structural changes in glass network and these glasses exhibit both electronic and ionic conductivity.
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Chen, Lu, e Ying Dai. "Effects of Iron Oxide on the Crystallization of Calcium Alumino-Silicate Glass". Key Engineering Materials 680 (febbraio 2016): 293–96. http://dx.doi.org/10.4028/www.scientific.net/kem.680.293.

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Different amounts of iron oxide (Fe2O3) were added into a base calcium alumino-silicate glass (CaO 40, Al2O3 9, SiO2 51 wt%). The crystallization behavior of the glassed was investigated by DTA, XRD, SEM and optical microscopy. DTA analysis on the samples with and without the iron additions shows that the iron-containing glasses obviously absorb more heat energy than the base glass. All the glasses show two endothermal peaks correspondent to two transition temperatures, Tg1 and Tg2, indicating the existence of phase separation. Compared with the base glass, an initial addition of 5wt% Fe2O3 does not result in significant changes in Tg1, but a large decrease in Tg2 is observed. Further additions of 10 and 15wt% Fe2O3, both Tg1 and Tg2 decreases. The iron-containing glasses show two crystallization peaks in their DTA curves. Fe2O3 facilitates the crystallization of the calcium alumino-silicate glass indicated by the decreased activation energy and increased Avrami exponent. SEM observations evidenced that the crystallintes in the heat treated samples are nanosized. It is evidenced that the base glass and the glasses containing 5 and 10 wt% Fe2O3 are surface crystallized upon heat-treatment and the main crystalline phase is wollastonite. The surface crystallization layer and the grain size increase with Fe2O3. However, an addition of 15wt% Fe2O3 results in a bulk crystallization leading to the formation of iron-and aluminum-containing phases.
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De Aza, P. N., A. H. De Aza, P. Pena e S. De Aza. "Vidrios y Vitrocerámicos Bioactivos". Boletín de la Sociedad Española de Cerámica y Vidrio 46, n. 2 (30 aprile 2007): 45–55. http://dx.doi.org/10.3989/cyv.2007.v46.i2.249.

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Mehrer, Helmut. "Diffusion in Metallic Glasses and in Oxide Glasses - An Overview". Defect and Diffusion Forum 413 (17 dicembre 2021): 109–24. http://dx.doi.org/10.4028/www.scientific.net/ddf.413.109.

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We remind the reader to some common features of metallic and oxide glasses. We then introduce the radiotracer method for diffusion studies, which can be applied for both types of glasses. We provide an overview on diffusion in metallic glasses in which we consider both types of metallic glasses – conventional and bulk metallic glasses. In the last part we discuss diffusion and ionic conduction in oxide glasses. For ionic glasses, conductivity measurements are an important complement to tracer diffusion studies. We remind the reader to the method of impedance spectroscopy. We discuss results for soda-lime silicate glasses, single alkali borate glasses and mixed alkali borate glasses and present evidence for collective jump processes in glasses.
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Loehman, Ronald E. "Oxynitride Glasses". MRS Bulletin 12, n. 5 (agosto 1987): 26–31. http://dx.doi.org/10.1557/s0883769400067476.

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Research on oxynitride glasses has expanded considerably since the first systematic compositional investigations were begun some ten years ago. This review will briefly introduce that work with an emphasis on more recent developments. Also included is some discussion of the applications of oxynitride glasses in both bulk and thin film form. The literature review is selective, however, and the recently developed phosphorus oxynitride glasses are only briefly mentioned. For more detailed information on earlier work on silicon oxynitride glasses see the reviews by Jack and Loehman. For discussions of phosphorus oxynitride glasses see Marchand, Peng and Day, and Rajaram and Day.The development of bulk oxynitride glasses has been closely associated with research on Si3N4 and other nitrogen-containing ceramics. The initial discovery that large amounts of nitrogen can be incorporated in silicate glasses originated with analyses of glassy grain boundary phases in Si3N4 that was hot-pressed or sintered with different additives to promote liquid phase formation at the processing temperature. (Some applications of oxynitride glasses take advantage of that close connection to Si3N4. See Applications of Oxynitride Glasses below.) Later, systematic study of the bulk oxynitride glasses showed that nitrogen incorporation increases density, hardness, glass transition temperature and fracture toughness, and, to a certain extent, decreases the thermal expansion coefficient. Nitrogen additions also tend to lower glass solubility in aqueous solutions.
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Coniglio, Antonio. "Spin glasses, glasses and granular materials". Philosophical Magazine B 77, n. 2 (febbraio 1998): 213–19. http://dx.doi.org/10.1080/13642819808204946.

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Tesi sul tema "Glasses"

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Leuzzi, Luca. "Thermodynamics of glassy systems glasses, spin glasses and optimization /". [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/66345.

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Wootton, Andrew Michael. "Silicon oxycarbide glasses and glass-ceramics". Thesis, University of Warwick, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310015.

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Rappensberger, Csaba Ferenc. "Novel rare-earth aluminosilicate glasses and glass-ceramics". Thesis, University of Warwick, 1996. http://wrap.warwick.ac.uk/56937/.

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Zhang, Endang. "Fibre reinforcement of oxynitride glasses and glass-ceramics". Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320017.

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Conca, Luca. "Mechanical properties of polymer glasses : Mechanical properties of polymer glasses". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1050/document.

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Ce manuscrit présente des récentes extensions au modèle PFVD, basé sur l'hétérogénéité de la dynamique des polymères vitreux à l'échelle de quelques nanomètres et résolu par simulation en 3D, afin de fournir une description physique unifiée des propriétés mécaniques et dynamiques des polymères vitreux soumis à déformation plastique. Trois sujets principaux sont traités : La plastification. Sous déformation, les polymères atteignent le seuil de plasticité (yield) à quelques pourcents de déformation et quelques dizaines de MPa. Nous proposons que l'énergie élastique absorbée à l'échelle des hétérogénéités dynamiques accélère la dynamique locale. On observe contraintes ultimes de quelques dizaines de MPa à quelques pourcents de déformation et que la plastification est due à un nombre relativement petit d'événements locaux. Il a été observé que la dynamique devient plus rapide et homogène dans le régime plastique et que la mobilité moyenne atteint une valeur stationnaire, linéaire avec le taux de déformation. Nous proposons que la contrainte locale stimule la diffusion de monomères des domaines lents à ceux rapides (mécanisme de facilitation) et accélère dynamique locale. Ceci permets d'observer l'homogénéisation de la dynamique, avec des caractéristiques proches de l'expérience. L'écrouissage, dans les polymères enchevêtrés ou réticulés. A grande déformation, la contrainte augmente avec une pente caractéristique d'ordre 10 – 100 MPa au-dessous de la transition vitreuse. De manière analogue à une théorie récente, nous proposons que la déformation locale oriente les monomères dans la direction d'étirage et ralentie la dynamique, suite à l'intensification des interactions locales. Les modules d'écrouissage mesurés, les effets de la réticulation et du taux de déformation sont comparables aux données expérimentales. En outre, on trouve que l'écrouissage a un effet stabilisateur sur les phénomènes de localisation et sur les bandes de cisaillement
This manuscript presents recent extensions to the PFVD model, based on the heterogeneity of theh dynamics of glassy polymers at the scale of a few nanometers et solved by 3D numerical simulation, which aim at providing a unified physical description of the mechanical and dynamical properties of glassy polymers during plastic deformation. Three main topics are treated: Plasticization. Under applied deformation, polymers undergo yield at strains of a few percent and stresses of some 10 MPa.We propose that the elastic energy stored at the scale of dynamical heterogeneities accelerates local dynamics. We observe yield stresses of a few 10 MPa are obtained at a few percent of deformation and that plastification is due to a relatively small amount of local yields. It has been observed that dynamics becomes faster and more homogeneous close to yield and that the average mobility attains a stationary value, linear with the strain rate. We propose that stress-induced acceleration of the dynamics enhances the diffusion of monomers from slow domains to fast ones (facilitation mechanism), accelerating local dynamics. This allows for obtaining the homogeneisation of the dynamics, with the same features observed during experiments. Strain-hardening, in highly entangled and cross-linked polymers. At large strain, stress increases with increasing strain, with a characteristic slope (hardening modulus) of order 10 – 100 MPa well below the glass transition. Analogously to a recent theory, we propose that local deformation orients monomers in the drawing direction and slows dows the dynamics, as a consequence of the intensification of local interactions. The hardening moduli mesured, the effect of reticulation and of strain rate are comparable with experimental data. In addition, strain-hardening is found to have a stabilizing effect over strain localization and shear banding
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Brüning, Ralf. "Structural relaxation and the glass transition in metallic glasses". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=74345.

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This thesis presents for the first time direct structural measurements of both reversible and irreversible structural relaxation and the glass transition in the metal-metalloid glass Pd$ sb{40}$Ni$ sb{40}$P$ sb{20}$. The techniques have been x-ray diffraction and Mossbauer spectroscopy, and a new analysis method for changes of amorphous diffraction patterns was developed.
It is found that irreversible relaxation proceeds by many local shear-type motions involving the metal atoms, and that it is accompanied by a small densification. Reversible relaxation at high annealing temperatures entails the same microscopic processes, but it does not change the density of the glass. The type of atomic processes changes continuously as the annealing temperature is lowered, and at sufficiently low temperatures the distribution of metal atoms remains constant, so that reversible relaxation then proceeds via rearrangement of the metalloid atoms. This rearrangement leads to more ordered, but less isotropic atomic sites.
The second part of the thesis is concerned with the motion of the atoms in a metallic glass below and above the glass transition. Mossbauer spectroscopy allows the direct measurement of vibrational and diffusional motion. The increase of the amplitude of atomic vibration has the same temperature dependence as the increase in volume that marks the glass transition, thus the two processes are governed by the same mechanism. The directly measured diffusional motion is in agreement with macroscopic measurements of diffusion.
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De, Mestral François. "Calcium phosphate glasses and glass-ceramics for medical applications". Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65405.

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Kansal, Ishu. "Diopside-fluorapatite-wollastonite based bioactive glasses and glass-ceramics". Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/14827.

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Doutoramento em Ciência e Engenharia dos Materiais
Bioactive glasses and glass–ceramics are a class of biomaterials which elicit special response on their surface when in contact with biological fluids, leading to strong bonding to living tissue. This particular trait along with good sintering ability and high mechanical strength make them ideal materials for scaffold fabrication. The work presented in this thesis is directed towards understanding the composition-structure-property relationships in potentially bioactive glasses designed in CaOMgOP2O5SiO2F system, in some cases with added Na2O. The main emphasis has been on unearthing the influence of glass composition on molecular structure, sintering ability and bioactivity of phosphosilicate glasses. The parent glass compositions have been designed in the primary crystallization field of the pseudo-ternary system of diopside (CaO•MgO•2SiO2) – fluorapatite (9CaO•3P2O5•CaF2) – wollastonite (CaO•SiO2), followed by studying the impact of compositional variations on the structure-property relationships and sintering ability of these glasses. All the glasses investigated in this work have been synthesized via melt-quenching route and have been characterized for their molecular structure, sintering ability, chemical degradation and bioactivity using wide array of experimental tools and techniques. It has been shown that in all investigated glass compositions the silicate network was mainly dominated by Q2 units while phosphate in all the glasses was found to be coordinated in orthophosphate environment. The glass compositions designed in alkali-free region of diopside – fluorapatite system demonstrated excellent sintering ability and good bioactivity in order to qualify them as potential materials for scaffold fabrication while alkali-rich bioactive glasses not only hinder the densification during sintering but also induce cytotoxicity in vitro, thus, are not ideal candidates for in vitro tissue engineering. One of our bioglass compositions with low sodium content has been tested successfully both in vivo and in preliminary clinical trials. But this work needs to be continued and deepened. The dispersing of fine glass particles in aqueous media or in other suitable solvents, and the study of the most important factors that affect the rheology of the suspensions are essential steps to enable the manufacture of porous structures with tailor-made hierarchical pores by advanced processing techniques such as Robocasting.
Os vidros e vitrocerâmicos bioactivos são uma classe de biomateriais que induzem uma resposta especial à sua superfície quando em contacto com fluidos biológicos que conduz a uma forte ligação ao tecido vivo. Esta característica particular conjugada com uma boa aptidão para a sinterização e elevada resistência mecânica torna estes materiais ideais para a fabricação de estruturas de suporte à regeneração óssea. O trabalho apresentado nesta tese pretende dar um contributo para uma melhor compreensão das relações entre composição-estrutura-propriedades em vidros potencialmente bioactivos com composições no sistema CaOMgOP2O5SiO2F, em alguns casos com a adição de Na2O. O estudo da influência exercida pela composição do vidro na estrutura molecular, capacidade de sinterização e nível de bioactividade dos vidros fosfosilicatados foi objecto de especial atenção. As composições vítreas foram concebidas no campo da cristalização primária do pseudo sistema ternário do diópsido (CaO•MgO•2SiO2) – fluorapatite (9CaO•3P2O5•CaF2) – wollastonite, e estudou-se o impacto das variações composicionais na estrutura, nas propriedades e na capacidade de sinterização destes vidros. Todos os vidros investigados neste trabalho foram preparados por fusão e fritagem e caracterizados quanto à sua estrutura molecular, capacidade de sinterização, degradação química e bioactividade, usando uma grande variedade de técnicas experimentais. Ficou demonstrado que em todas as composições de vidro investigadas a rede de silicato era dominada principalmente por unidades Q2 enquanto o fosfato se encontrava coordenado em ambiente de ortofosfato. As composições de biovidros isentas de alcalinos do sistema diópsido–fluorapatite demonstram possuir excelente capacidade de sinterização e elevados níveis de bioactividade, atributos que os qualificam como materiais promissores para a fabricação de estruturas de suporte à regeneração de tecidos ósseos, enquanto os vidros bioactivos contendo alcalinos foram mais difíceis de densificar durante a sinterização e induziram citotoxicidade in vitro, não sendo candidatos ideais para a engenharia de tecidos. Uma das nossas composições de biovidro com um baixo teor de sódio foi testada com sucesso tanto in vivo como em ensaios clínicos preliminares. Mas este trabalho precisa de ser continuado e aprofundado. A dispersão de fritas moídas em meio aquoso ou outros solventes adequados, e o estudo dos factores mais relevantes que condicionam a reologia das suspensões são etapas essenciais para viabilizar o processo de fabrico de suportes porosos com estruturas hierárquicas de poros feitas por medida através de técnicas de processamento avançadas tais como o Robocasting.
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Goel, Ashutosh. "Clinopyroxene based glasses and glass-ceramics for functional applications". Doctoral thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2323.

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Abstract (sommario):
Doutoramento em Ciência e Engenharia de Materiais
As piroxenas são um vasto grupo de silicatos minerais encontrados em muitas rochas ígneas e metamórficas. Na sua forma mais simples, estes silicatos são constituídas por cadeias de SiO3 ligando grupos tetrahédricos de SiO4. A fórmula química geral das piroxenas é M2M1T2O6, onde M2 se refere a catiões geralmente em uma coordenação octaédrica distorcida (Mg2+, Fe2+, Mn2+, Li+, Ca2+, Na+), M1 refere-se a catiões numa coordenação octaédrica regular (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), e T a catiões em coordenação tetrahédrica (Si4+, Al3+, Fe3+). As piroxenas com estrutura monoclínica são designadas de clinopiroxenes. A estabilidade das clinopyroxenes num espectro de composições químicas amplo, em conjugação com a possibilidade de ajustar as suas propriedades físicas e químicas e a durabilidade química, têm gerado um interesse mundial devido a suas aplicações em ciência e tecnologia de materiais. Este trabalho trata do desenvolvimento de vidros e de vitro-cerâmicos baseadas de clinopiroxenas para aplicações funcionais. O estudo teve objectivos científicos e tecnológicos; nomeadamente, adquirir conhecimentos fundamentais sobre a formação de fases cristalinas e soluções sólidas em determinados sistemas vitro-cerâmicos, e avaliar a viabilidade de aplicação dos novos materiais em diferentes áreas tecnológicas, com especial ênfase sobre a selagem em células de combustível de óxido sólido (SOFC). Com este intuito, prepararam-se vários vidros e materiais vitro-cerâmicos ao longo das juntas Enstatite (MgSiO3) - diopsídio (CaMgSi2O6) e diopsídio (CaMgSi2O6) - Ca - Tschermak (CaAlSi2O6), os quais foram caracterizados através de um vasto leque de técnicas. Todos os vidros foram preparados por fusão-arrefecimento enquanto os vitro-cerâmicos foram obtidos quer por sinterização e cristalização de fritas, quer por nucleação e cristalização de vidros monolíticos. Estudaram-se ainda os efeitos de várias substituições iónicas em composições de diopsídio contendo Al na estrutura, sinterização e no comportamento durante a cristalização de vidros e nas propriedades dos materiais vitro-cerâmicos, com relevância para a sua aplicação como selantes em SOFC. Verificou-se que Foi observado que os vidros/vitro-cerâmicos à base de enstatite não apresentavam as características necessárias para serem usados como materiais selantes em SOFC, enquanto as melhores propriedades apresentadas pelos vitro-cerâmicos à base de diopsídio qualificaram-nos para futuros estudos neste tipo de aplicações. Para além de investigar a adequação dos vitro-cerâmicos à base de clinopyroxene como selantes, esta tese tem também como objetivo estudar a influência dos agentes de nucleação na nucleação em volume dos vitro-cerâmicos resultantes á base de diopsídio, de modo a qualificá-los como potenciais materiais hopedeiros de resíduos nucleares radioactivos.
The pyroxenes are a wide spread group rock-forming silicate minerals found in many igneous and metamorphic rocks. They are silicates that, in their simplest form, contain single SiO3 chains of linked SiO4 tetrahedra. The general chemical formula for pyroxenes is M2M1T2O6, where M2 refers to cations in a generally distorted octahedral coordination (Mg2+, Fe2+, Mn+, Li+, Ca2+, Na+), M1 to cations in a regular octahedral coordination (Al3+, Fe3+, Ti4+, Cr3+, V3+, Ti3+, Zr4+, Sc3+, Zn2+, Mg2+, Fe2+, Mn2+), and T to tetrahedrally coordinated cations (Si4+, Al3+, Fe3+). Monoclinic pyroxenes are called clinopyroxenes. The stability of clinopyroxenes over a broad spectrum of chemical compositions, in conjunction with the possibility of achieving desired physical properties and high chemical durability, has generated a worldwide interest due to their applications in material science and technology. The present work deals with the development of clinopyroxene based glasses and glass-ceramics for functional applications. The objective of the study was dual, both scientific and technological; particularly to gain fundamental knowledge on the formation of crystalline phases and solid solutions in selected glass-ceramic systems, and to evaluate the feasibility for application of new materials in different technological areas with emphasis on sealing in solid oxide fuel cells (SOFC). In this pursuit, various glasses and glass-ceramics along Enstatite (MgSiO3) - Diopside (CaMgSi2O6) and Diopside (CaMgSi2O6) – Ca – Tschermak (CaAlSi2O6) joins have been prepared and characterized by a wide array of characterization techniques. All the glasses were prepared by melt-quenching technique while glass-ceramics were produced either by sintering and crystallization of glass powders or by nucleation and crystallization in monolithic glasses. Furthermore, influence of various ionic substitutions/additions in Alcontaining diopside on the structure, sintering and crystallization behaviour of glasses and properties of resultant glass-ceramics has been investigated, in relevance with final application as sealants in SOFC. It has been observed that enstatite based glasses/glass-ceramics do not exhibit requisite characteristics in order to qualify for the job of sealing in SOFC while the superior properties exhibited by diopside based glass-ceramics qualify them for further experimentation as SOFC sealants. Apart from investigating the suitability of clinopyroxene based glass-ceramics as sealants, this thesis also aims to study the influence of nucleating agents on the volume nucleation in the resultant diopside based glass-ceramics so as to qualify them for further experimentation as hosts for radioactive nuclear wastes.
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Parupudi, Aarti. "Singing wine glasses". Kansas State University, 2015. http://hdl.handle.net/2097/19706.

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Master of Science
Computing and Information Sciences
Daniel A. Andresen
One among the many inventions of Benjamin Franklin is the Glass Armonica, a musical instrument whose sound source was a series of resonating glass vessels. However, the Irish musician Richard Pockrich is typically credited as the first to play an instrument composed of glass vessels, called the Glass Harp in 1741, by rubbing his fingers around the rims. In this project “Singing Wine Glasses”, the principle of Franklin’s glass armonica is demonstrated with a wine glass. One hand is used to hold the glass steady at the base. The rim of glass is gently pressed with a moistened finger of the other hand and drawn in a circle around. When the pressure and amount of moisture are just right, the slight friction between the finger and the rim of glass causes vibrations in the sides of the glass. At a particular frequency, called the resonant frequency, the sides of the glass will vibrate most easily. The resonant frequency of wine glasses is typically within the range of human hearing (20-20,000 Hz), so the resulting resonant vibration is heard as a tone. The glass starts to sing when the vibration gets the molecules moving at their natural frequency. The resonant frequency changes with the amount of water filled in the glass. This android application deals with virtual glasses that serve the purpose of wine glasses filled with different amounts of water. Swiping on the glass edges would produce music, as per Franklin’s principle. The users would be free to select the number of glasses they want to play, and the amount of water-level in each glass. This application would also come with an enhanced feature of sustaining a particular note until the finger is released from the glass.
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Libri sul tema "Glasses"

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Reese, Bob. Glasses. Chicago: Childrens Press, 1992.

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Glasses. London: MQ Pub., 1999.

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Zawistoski, Ann Gwinn. Glasses. Madison, WI: Peeps Eyewear, LLC, 2014.

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Binoculars, opera glasses and field glasses. Princes Risborough, Buckinghamshire [England]: Shire Publications, Ltd., 1995.

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Gemma, Stockdale, Cooper Matthew e Holliday Liz, a cura di. Elmer's glasses. Bradford: Horton Print Group, 2003.

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E, Comyns Alan, a cura di. Fluoride glasses. Chichester [England]: Published on behalf of the Society of Chemical Industry by Wiley, 1989.

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Rhude, Steven. Natalie's glasses. Lunenburg, N.S: MacIntyre Purcell Pub., 2011.

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Boccaccini, Aldo R., Delia S. Brauer e Leena Hupa, a cura di. Bioactive Glasses. Cambridge: Royal Society of Chemistry, 2016. http://dx.doi.org/10.1039/9781782622017.

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Roth, Connie, a cura di. Polymer Glasses. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2016. http://dx.doi.org/10.1201/9781315305158.

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Roth, Connie B. Polymer Glasses. Boca Raton, FL : CRC Press, Taylor & Francis Group, [2016] |: CRC Press, 2016. http://dx.doi.org/10.4324/9781315305158.

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Capitoli di libri sul tema "Glasses"

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Souletie, J. "Spin-Glasses Versus Glassy Glasses". In Structure and Properties of Ionomers, 247–54. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3829-8_20.

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Ford, N., e R. Todbunter. "Applications of microporous glasses". In Glasses and Glass-Ceramics, 203–25. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0817-8_6.

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Krause, Dieter. "Glasses". In Springer Handbook of Materials Data, 541–88. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-69743-7_19.

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Zarzycki, J., G. H. Frischat e D. M. Herlach. "Glasses". In Fluid Sciences and Materials Science in Space, 599–636. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-46613-7_17.

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Doremus, R. H. "Glasses". In Materials Sciences in Space, 447–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82761-7_18.

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Kurchan, Jorge. "Glasses". In Glasses and Grains, 1–24. Basel: Springer Basel, 2011. http://dx.doi.org/10.1007/978-3-0348-0084-6_1.

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Bolton, William, e R. A. Higgins. "Glasses". In Materials for Engineers and Technicians, 321–28. Seventh edition. | Abingdon, Oxon ; New York, NY : Routledge, 2021.: Routledge, 2020. http://dx.doi.org/10.1201/9781003082446-22.

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Dupree, R., e D. Holland. "MAS NMR: a new spectroscopic technique for structure determination in glasses and ceramics". In Glasses and Glass-Ceramics, 1–40. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0817-8_1.

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Prewo, Karl M. "Fibre reinforced glasses and glass-ceramics". In Glasses and Glass-Ceramics, 336–68. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0817-8_10.

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Pettifer, R. F. "X-ray absorption studies of glass structure". In Glasses and Glass-Ceramics, 41–58. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0817-8_2.

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Atti di convegni sul tema "Glasses"

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Ojovan, Michael, Guenter Mo¨bus, Jim Tsai, Stuart Cook e Guang Yang. "On Fluidization of Borosilicate Glasses in Intense Radiation Fields". In ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2009. http://dx.doi.org/10.1115/icem2009-16055.

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The viscosity is rate-limiting for many processes in glassy materials such as homogenisation and crystallisation. Changes in the viscous flow behaviour in conditions of long-term irradiation are of particular interest for glassy materials used in nuclear installations as well as for nuclear waste immobilising glasses. We analyse the viscous flow behaviour of oxide amorphous materials in conditions of electron-irradiation using the congruent bond lattice model of oxide materials accounting for the flow-mediating role of broken bonds termed configurons. An explicit equation of viscosity was obtained which is in agreement with experimental data for non-irradiated glasses and shows for irradiated glasses, first, a significant decrease of viscosity, and, second, a stepwise reduction of the activation energy of flow. An equation for glass-transition temperature was derived which shows that irradiated glasses have lower glass transition temperatures. Intensive electron irradiation of glasses causes their fluidisation due to non-thermal bond breaking and can occur below the glass transition temperature. Due to surface tension forces fluidisation of glasses at enough high electron flux densities can result in modification of nano-size volumes and particles such as those experimentally observed under TEM electron beams.
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Walton, D. "The glass transition in orientational glasses". In Slow dynamics in condensed matter. AIP, 1992. http://dx.doi.org/10.1063/1.42449.

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Bouchaud, J. Ph. "Aging in glassy systems: Traps and Mode-Coupling theory". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301451.

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Micoulaut, Matthieu. "Solvable models of glass transition". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301468.

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Barrat, Jean-Louis. "Mode coupling theories". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301450.

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Schober, H. R. "Molecular dynamics in amorphous solids and liquids". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301459.

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Teichler, H. "The liquid-glass transition in the". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301460.

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Buchenau, U. "Neutron and X-ray scattering from glasses". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301447.

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Pelous, J., C. Levelut e F. Terki. "Relaxations and vibrations in glasses: Experiments". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301448.

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Gaskell, Philip H. "Medium-range structure in amorphous and crystalline". In PHYSICS OF GLASSES. ASCE, 1999. http://dx.doi.org/10.1063/1.1301449.

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Rapporti di organizzazioni sul tema "Glasses"

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Yu, Clare. "Coulomb Glasses". Office of Scientific and Technical Information (OSTI), dicembre 2004. http://dx.doi.org/10.2172/835841.

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Gal'perin, Yu M., V. G. Karpov e Володимир Миколайович Соловйов. Density of vibrational states in glasses. Springer, novembre 1988. http://dx.doi.org/10.31812/0564/1005.

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A theory of the vibrational spectra of glasses, based on allowance for the statistical fluctuations of the local elastic constants, is proposed. The existence is established of two characteristic energies h, and h, , dividing the spectrum into regions of qualitatively different behavior of the density of states n (h). At low frequencices w 4 w, the increase of the density of states is determined by the additive contributions of phonons and mutually noninteracting quasilocal vibrations in random soft atomic potentials in the glass. In the intermediate region w , 5 w 5 w, the quasilocal vibrations interact strongly with phonons, and this makes their contributions superadditive. For w > w, the growth of n (h) slows down. As a result, n (h) increases at first more rapidly and then more slowly than the Debye density of states. An analytical expression for n (h) is obtained in the T-matrix formalism in the region w <a,, including the region of strong scattering. A numerical calculation of n (h) is performed in the coherent-potential approximation. The theory predicts qualitatively universal behavior of n (h) in different glasses.
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Gafney, Harry D. Photodeposition in Glasses. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1998. http://dx.doi.org/10.21236/ada336810.

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Matyas, Josef, Adam R. Huckleberry, Carmen P. Rodriguez, Jesse B. Lang, Antionette T. Owen e Albert A. Kruger. HLW Glass Studies: Development of Crystal-Tolerant HLW Glasses. Office of Scientific and Technical Information (OSTI), aprile 2012. http://dx.doi.org/10.2172/1062511.

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Beaudet, Madison. Memory Through Dark Glasses. Portland State University Library, gennaio 2013. http://dx.doi.org/10.15760/honors.7.

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Polk, Donald. Raman Spectra of Glasses. Fort Belvoir, VA: Defense Technical Information Center, novembre 1986. http://dx.doi.org/10.21236/ada203343.

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Hrma, Pavel R., Gregory F. Piepel, John D. Vienna, Scott K. Cooley, Dong-Sang Kim e Renee L. Russell. Database and Interim Glass Property Models for Hanford HLW Glasses. Office of Scientific and Technical Information (OSTI), luglio 2001. http://dx.doi.org/10.2172/787351.

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Hrma, Pavel R., Gregory F. Piepel, John D. Vienna, Scott K. Cooley, Dong-Sang Kim e Renee L. Russell. Database and Interim Glass Property Models for Hanford HLW Glasses. Office of Scientific and Technical Information (OSTI), luglio 2001. http://dx.doi.org/10.2172/965691.

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Ellison, A., S. Wolf, E. Buck, J. S. Luo, N. Dietz, J. K. Bates e W. L. Ebert. Laboratory testing of LITCO glasses. Office of Scientific and Technical Information (OSTI), giugno 1995. http://dx.doi.org/10.2172/80967.

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Ellison, A. G. J., D. L. Price, M. L. Saboungi, R. Z. Hu, T. Egami e W. S. Howells. Extended-range order in glasses. Office of Scientific and Technical Information (OSTI), novembre 1992. http://dx.doi.org/10.2172/10188255.

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