Дисертації з теми "Active Glass"
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Johansson, Wilhelm. "Optical active thin films on cover glass increasing the efficiency of photovoltaic modules." Thesis, Linnéuniversitetet, Institutionen för byggd miljö och energiteknik (BET), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-75044.
Повний текст джерелаLi, Shang-Shiou. "A Protocol to Determine the Performance of South Facing Double Glass Façade System-A Preliminary Study of Active/Passive Double Glass Façade Systems." Thesis, Virginia Tech, 2000. http://hdl.handle.net/10919/31802.
Повний текст джерелаMaster of Science
Fujita, Shunsuke. "Development of Rare Earth Doped Active Glass-Ceramics for White Light Emitting Diode and Optical Telecommunications." Kyoto University, 2010. http://hdl.handle.net/2433/120435.
Повний текст джерела0048
新制・課程博士
博士(人間・環境学)
甲第15469号
人博第499号
新制||人||122(附属図書館)
21||人博||499(吉田南総合図書館)
27947
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 田部 勢津久, 教授 杉山 雅人, 准教授 木下 俊哉
学位規則第4条第1項該当
Mabrouk, Mohamed Mostafa. "Preparation of PVA / Bioactive Glass nanocomposite scaffolds : in vitro studies for applications as biomaterials : association with active molecule." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S063/document.
Повний текст джерелаThe aim of the present work is the preparation of Bioactive Glass (BG) 46S6 by different techniques. Fabrication of composite scaffolds by using of Poly Vinyl Alcohol (PVA) and quaternary BG (two methods melting and sol-gel) with different ratios to the prepared scaffolds was carried out. Different factor affecting the final properties of the prepared composite scaffolds were investigated in this study, such as; temperature of treatment, BG particle size, polymer/glass ratio, microstructure, porosity, biodegradation, bioactivity, and drug release. The thermal behavior of the prepared bioactive glass by sol-gel and melting techniques were identified using Differential Scanning Calorimetric/Thermo Gravimetric (DSC/TG) or Differential Thermal Analysis/Thermo Gravimetric (DTA /TG). The elemental composition of the prepared bioactive glasses was determined by X-rays Fluorescence (XRF) to confirm that the prepared bioactive glasses have the same elemental compositions and high purity for biomedical applications. The particle size of the prepared bioactive glass was determined by Transmission Electron Microscopic (TEM). Nano-bioactive glass could be obtained by modified sol-gel and the obtained particle size ranged between 40 to 61 nm. The prepared bioactive glass by both applied methods has the same amorphous phase and all identified groups as well as. The porous scaffold has 85% porosity with a slight decrease by increasing the glass contents. The degradation rate decreased by increasing of glass content in the prepared scaffolds. The bioactivity of the prepared composite scaffolds was evaluated by XRD, FTIR, SEM coupled with EDX and Inductively Coupled Plasma-Optical Emission Spectroscopic (ICP-OES). It has been observed that after soaking in Simulated Body Fluid (SBF), there was an apatite layer formed on the surface of the prepared samples with different thickness depending on the glass particle size and polymer/glass ratio
GALLICHI, NOTTIANI DUCCIO. "Advanced phosphate glasses for photonics: from materials to applications." Doctoral thesis, Politecnico di Torino, 2021. http://hdl.handle.net/11583/2903486.
Повний текст джерелаGerlich, Jakub. "Kombinovaný vliv skelných vláken a oxidu titaničitého jako aditiv záporné elektrody na vlastnosti olověného akumulátoru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-318097.
Повний текст джерелаPyreňová, Eliška. "Studium vlastností polymery modifikovaných malt využívající pucolánově aktivní materiály." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240307.
Повний текст джерелаBorhan, Tumadhir Merawi. "Thermal and structural behaviour of basalt fibre reinforced glass concrete." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/thermal-and-structural-behaviour-of-basalt-fibre-reinforced-glass-concrete(2fcc3a9a-2012-4261-966b-4ff37420e032).html.
Повний текст джерелаBou, Alameda María Elena. "Through the Looking Glass: Understanding a Complex Relationship between Knowledge and Action." Doctoral thesis, Universitat Ramon Llull, 2006. http://hdl.handle.net/10803/9175.
Повний текст джерелаThe empirical work in a local labour placement company and in a multinational consultancy firm shows that practitioners resort to a host of different expressions of knowledge (or bundle of knowledge) when acting. Therefore, the prevailing role of explicit knowledge and the need for being a precedent in order to be applied is called into question.
The empirical work also reveals that the bundle of knowledge is not static. It evolves over time and at the same time the prevailing type of knowledge varies depending on the type of practice and the practitioner's level of expertise. Therefore, the results underscore the fact that the relationship between knowledge and action is more dynamic and that both interplay simultaneously.
Finally, this research shows that formal company categorisations (senior/junior) describe different practices rather than correspond to differential stocks of formal knowledge. This means that even when experts and novices apparently seem to be doing the same job, their actions are different as they are constituted through different combinations of knowledge types and orders of relevance. These results seem to point toward the fact that the essence of expertise resides in the expert's ability to reframe. He is able to reconstruct practice, whether by reframing his tasks or the overarching context.
Одинцова, Олександра Павлівна. "Безпігментні одношарові склоемалеві покриття для побутової техніки". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33516.
Повний текст джерелаThe dissertation on competion of a scientific degree of the candidate of engineering science on a speciality 05.17.11 "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2017. The dissertation is devoted to the development of pigments free direct chemically and thermally resistant dark-colored glass-enamel coatings for the protection of household appliances, in particular kitchen gas and electric plates, obtained by the technology POESTA. The bases of obtaining the coatings of this type are synthesized, according to which the glass matrix is developed with the given physicochemical properties, on the basis of which glassmelee frit is obtained by introducing into the optimized composition of the MS complex agglomer activator, simultaneously performing the role of the active coloring complex which combines the specified strength characteristics of pigments free direct glass-enamel coatings with their dark coloring. The boundaries of the values of structural factors, which provide a solid structure of the silica-oxygen glass frame in the system R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ and the specified level of its structurally dependent performance properties due to the established ratios of glass modifiers and modifiers. The composition and ratio of the complex coupler activator have been developed taking into account its influence on the strength characteristics of the glass-enamel-steel system, the corrosion capacity of the glass-fiber alloy and the operational properties of the coatings at the firing temperatures of 800 to 830 °C. Selected the ionic mechanism of color, which was realized by the components of the filling station, and the color coordinates are established in the XYZ, RGB, L*a*b, according to RAL. Industrial and laboratory-industrial tests were carried and practical recommendations for the use of development results are developed.
Одинцова, Олександра Павлівна. "Безпігментні одношарові склоемалеві покриття для побутової техніки". Thesis, НТУ "ХПІ", 2017. http://repository.kpi.kharkov.ua/handle/KhPI-Press/33515.
Повний текст джерелаThe dissertation on competion of a scientific degree of the candidate of engineering science on a speciality 05.17.11 "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2017. The dissertation is devoted to the development of pigments free direct chemically and thermally resistant dark-colored glass-enamel coatings for the protection of household appliances, in particular kitchen gas and electric plates, obtained by the technology POESTA. The bases of obtaining the coatings of this type are synthesized, according to which the glass matrix is developed with the given physicochemical properties, on the basis of which glassmelee frit is obtained by introducing into the optimized composition of the MS complex agglomer activator, simultaneously performing the role of the active coloring complex which combines the specified strength characteristics of pigments free direct glass-enamel coatings with their dark coloring. The boundaries of the values of structural factors, which provide a solid structure of the silica-oxygen glass frame in the system R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ and the specified level of its structurally dependent performance properties due to the established ratios of glass modifiers and modifiers. The composition and ratio of the complex coupler activator have been developed taking into account its influence on the strength characteristics of the glass-enamel-steel system, the corrosion capacity of the glass-fiber alloy and the operational properties of the coatings at the firing temperatures of 800 to 830 °C. Selected the ionic mechanism of color, which was realized by the components of the filling station, and the color coordinates are established in the XYZ, RGB, L*a*b, according to RAL. Industrial and laboratory-industrial tests were carried and practical recommendations for the use of development results are developed.
Casari, Fernanda. "Alquimia e vidro = espaços e limites entre matéria e imaginação." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/284425.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes
Made available in DSpace on 2018-08-19T14:54:37Z (GMT). No. of bitstreams: 1 Casari_Fernanda_M.pdf: 7744105 bytes, checksum: 3fc3dc2db4a51a52e20b9fd49e7717dd (MD5) Previous issue date: 2011
Resumo: A relação entre materiais, procedimentos e poéticas desenvolvidas durante o processo de criação artística são questões que me acompanham desde a graduação em Artes Plásticas. Este trabalho tem como objetivo unir estas questões e apresentar o caminho percorrido para a realização de objetos em vidro. Abordo a Alquimia em alguns aspectos históricos, sua relação com o vidro e em como esta temática é inspiradora para o meu processo de criação. Aponto características materiais e poéticas do vidro e a partir da técnica de vitrofusão (fusing), demonstro resultados de experimentações e o procedimento construtivo utilizado na realização dos objetos. Finalizo com a apresentação de duas séries de objetos realizados a partir de temáticas alquímicas
Abstract: The relationship between materials, procedures and the poetics developed during the creative artistic process are all issues that have been a constant for me, ever since I got my degree in Fine Art. The purpose of this work is to unify all these issues and to present the path followed towards the creation of glass objects. I approach Alchemy on some historical levels, its relation to glass and in which manner this thematic is inspirational to my creative process. I highlight the characteristics pertaining to the material and poetics of glass and, through the technique of fusing, I demonstrate the results of my experiments as well as the constructive procedure employed in the creation of the objects. I conclude with a presentation of two series of objects created from the alchemical thematic
Mestrado
Artes Visuais
Mestre em Artes
Khair, Ro’aa Mohammed Jafar Mohammed Mohammed. "Comparative in vitro study of selected physical properties of Activa, Cention N and Vitremer." University of the Western Cape, 2021. http://hdl.handle.net/11394/8144.
Повний текст джерелаBackground: This study aimed to determine the association between dimensional change and surface roughness (Ra) of Vitremer, Activa and Cention N after immersing them into two different media: acidic and artificial saliva media for the period of a year. Measurements were made at 10 time intervals during the observation period. Methodology: This was a quantitative and qualitative study. For the quantitative part, a total of 60 specimens were tested, 20 specimens for each material. The 20 specimens were further divided into 10 specimens. Ten were immersed in acidic media and the rest in saliva media. A measurement of the weight, height, and Ra was carried out as follows: day 0, day 1, day 2, day 7, day 21, day 28, day 60, day 90, day 180 and day 365. Scanning electron microscopy (SEM) was used to examine the surface of each material qualitatively pre and post immersion in the two media. For fluoride measurements, an additional five samples from each material were left suspended in the de-ionized water by the use of dental floss. The materials were moved to new specimen jars after the completion of day 1, 2, 3, 4, 5, 6, 7, 14, 21 and 28. All the specimen jars had been kept for the fluoride measurements. Results: Non-parametric tests were used to analyze the data. Linear regression analysis was used to measure the association between weight, height or surface roughness (Ra) and immersion time for a year. The result of this test showed that Vitremer had a significant association between the weight (p = 0.000), height (p = 0.007) and Ra (p = 0.001) when it was immersed in acidic media. On the other hand, when Vitremer was immersed in saliva media, only the weight variable showed a significant association (p = 0.002). For Cention N, significant association was found for only Ra when immersed in acidic media (p = 0.000). Finally, for Activa, all the studied associations; the weight, height and Ra in both media were found to be insignificant. For saliva media, there was a significant weight change between the three materials during all 10 periods of time (p = 0.000). In the first six months, Cention N demonstrated a significant increase in weight changes followed by Vitremer, then Activa. Yet, after a year, the difference between Cention N and Vitremer became insignificant and Activa showed the least weight changes. There was not a significant difference between the materials in terms of height and Ra measurements. The fluoride experiment was not successful due to technical issues during pH measurements of the collected solutions. For comparison of the studied parameters between the three materials, the Kruskal-Wallis test was used. In acidic media, there was a significant difference between the materials in term of weight change in 10 periods of time (p = 0.000). In particular, after a two month period, Cention N had the highest weight, followed by Vitremer and then by Activa. The difference between Vitremer and Activa became insignificant throughout the rest of the experimental time frame. All the height measurements between the three materials were found to be insignificant except for day 365 (p = 0.048), where both Activa and Cention N were found to be significantly higher than Vitremer. For the Ra comparison, in the first two weeks, particularly day 1, 7 and 14, Cention N had significantly the lowest Ra among the other materials. As the three materials aged in the acidic media (day 180), Vitremer had significantly the highest Ra values. Cention N showed higher Ra values than Activa; nonetheless this difference was not significant. The SEM images showed loss of some particles in all post-experimental images of the materials in acidic media. Vitremer showed the widest cracks with the loss of fillers. In saliva media, there was also loss of particles but to a lesser extent than in acidic media. Yet, the post-experimental image of Activa in saliva resembled the pre-experimental one. Conclusion: Within the limitations of the study, the best material to resist Ra from prolonged acidic attack was Activa followed by Cention N and then Vitremer. Except for Vitremer, no significant changes in the Ra of the other materials were detected when the three materials were immersed in saliva media in the long term. In acidic media Vitremer tended to lose weight and height faster than Cention N and Activa over a year. Cention N is the best material to resist dimensional change. However, in artificial saliva Vitremer gained water rapidly. Activa did not absorb a lot of water and did not reject a lot of water; Activa demonstrated good dimensional stability and this property may be beneficial when compared to the other two materials tested. The clinical significance of the study: All the materials studied were subjected to dimensional and Ra changes following long-term exposure to acidic substances, but the newer materials (Cention N and Activa) seemed to be more dimensionally stable and resistant to Ra changes than the older, well-known material (Vitremer). This may influence a clinician’s choice of restorative material for use in pediatric dentistry.
Farano, Vincenzo. "An investigation into different phosphate glass processing routes and the role of phosphate glass in dental collagen-based scaffolds." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1192/document.
Повний текст джерелаThis thesis concerns the development of a new series of Sr-doped phosphate-based glasses for biomedical applications. Such glasses in powder form are envisaged to have applications in novel composite restorations where the following is achievable: dentin cell-mediated bioremineralization, dental pulp regeneration and as carrier for therapeutics or antibacterial ions.The initial aim was to produce soluble porous phosphate glasses using the sol-gel method (phosphate-alkoxide based sol-gel process). Knowing the effect that the variation of Ca content has on the dissolution properties of the glass, a series of glasses where Ca was progressively increased at the expense of Na was produced. The structure of the prepared samples was probed by XRD, XRF and FTIR to confirm the successful synthesis of the target phosphate-based glass compositions. After that a promising methodology was established, attempts were made to replace Ca with Sr. Different Sr sources were used without success due to the difficulty to fully dissolve those precursors in the sol-gel mixture. Subsequently, the issue of the toxicity of some precursors and solvents used in the sol-gel procedure was recognised. To overcome this obstacle, efforts were made to replace the toxic precursor chemicals with safer ones. Nevertheless, due to the low solubility of some new precursors and the low reactivity of others, the sol-gel process did not proceed in a predictable and reproducible fashion. At this stage, the sol-gel route was put aside, and two alternative soft and water-based chemical approaches were experimented: the precipitation method and the coacervation process. The first one was found to be unsuitable for our needs for two main reasons: 1) the presence of Na in the composition generated a crystalline material (instead of a glassy amorphous one); 2) the Ca/P ratio of our composition fell in the range of crystalline phase by using this method. In addition, the yield was really low. The second method (coacervation process) was a complete success. The glassy nature of the materials obtained was proved by XRD and XRF and the surface features were tested by BET and SEM. The process was retained for a while as the preferred synthesis route and both the scale-up effect and the possibility to add Sr were analysed. The production scale of the material was increased by 5 times and different Sr sources were tested to find the best one. XRD and XRF analysis proved both the success of the scale-up and the incorporation of the Sr in glass composition
Lalinde, Castrillón Luis Felipe. "Estudio de compuestos de GRC y adiciones activas: Propiedades mecánicas, envejecimiento acelerado y durabilidad." Doctoral thesis, Universitat Politècnica de València, 2020. http://hdl.handle.net/10251/157637.
Повний текст джерела[CAT] En l'àmbit dels materials compostos o compòsits per a la construcció, el ciment reforçat amb fibres de vidre (GRC, de l'anglès glass fiber reinforced cement) és el més extensament utilitzat, per les seves excel·lents propietats mecàniques (resistència a flexió i tenacitat). No obstant això, la durabilitat d'aquests compòsits s'ha demostrat crítica, i cal proposar alternatives. Les fibres usades, de caràcter àlcali-resistent (fibres AR, formades per agrupació de filaments), són atacades pel medi agressiu que imposa el ciment hidratat. Una alternativa interessant des del punt de vista tecnològic és la incorporació de materials cimentants suplementaris de caràcter putzolànic. L'objectiu d'aquest treball és estudiar la influència de les diferents addicions actives en morters de GRC, observant el comportament dels elements constitutius del material en condicions normals de curat, i també quan son sotmesos a processos d'envelliment controlat. Així mateix, s'analitza el comportament dels nous compòsits sotmesos a diferents mitjans agressius, avaluant la durabilitat i la millora dels compostos mitjançant la determinació de les seves propietats mecàniques, químiques i físiques. S'han elaborat provetes de GRC a través del procediment de mescla prèvia (premix) i s'ha determinat les seves propietats mecàniques (resistència a flexió, tenacitat, mòdul d'elasticitat). Addicionalment s'han quantificat els guanys de resistència al comparar compòsits GRC basats en ciment Portland (espècimens control) amb altres en què s'ha substituït fins al 60% d'aquest ciment per materials putzolànics. A l'objecte de millorar la reactivitat de les putzolanes, en alguns casos s'ha implementat un augment de la seva finor a través de la mòlta (cendres volants mòltes, CVm) o de processos de sonicació (fum de sílice sonicat, HSS). Els espècimens de GRC han estat sotmesos a un procés d'envelliment (tractament en aigua a 55ºC durant un període prolongat) i s'ha observat l'empitjorament molt significatiu de la resistència a flexió i la tenacitat d'aquells que posseeixen solament ciment Pòrtland com a component cimentant. Els compòsits GRC que contenen quantitats elevades de putzolana (60% de CVm) o mescles de putzolanes (50% CVm / 10% HSS, 50% CVm / 10% FCC) presenten una millora substancial de les propietats mecàniques respecte als GRC control. La millora d'aquests sistemes GRC amb elevats percentatges de putzolanes reactives s'han confirmat a través d'estudis físics i fisicoquímics: avaluació de densitat, absorció, estudis microscòpics (lupa i microscòpia electrònica de rastreig) i anàlisi termogravimètric. Pel que fa a la resposta dels compòsits GRC enfront de diferents dissolucions agressives, s'ha demostrat l'efecte beneficiós de la presència de putzolanes. Després de l'exposició dels morters de GRC a una dissolució de NH4Cl, el comportament mecànic dels morters putzolànics es millor que el morter GRC control: això es deu a la relació directa existent amb l'increment de la densitat i la disminució del grau d'absorció del compòsit amb la putzolana. Quan s¿ha avaluat les propietats dels morters de GRC després de la seva exposició a una dissolució H2SO4, s'observen diferències molt importants en l'evolució de la massa, resistència a flexió i tenacitat: els compòsits control són més afectats per l'acidesa del medi, de manera que la pèrdua de massa és molt significativa si es compara amb els GRC que presenten putzolanes. L'estada a l'empresa Saint Gobain Vetrotex, ha permès confirmar una gran similitud en els resultats obtinguts mitjançant els procediments seguits en el laboratori de la UPV (compostos de GRC amb premescla) comparats amb les pràctiques desenvolupades pel laboratori de materials de l'empresa (compostos de GRC projectat). S'han avaluat prototips per a la indústria de l'GRC projectat.
[EN] In the field of composite materials for construction, glass fiber reinforced cement (GRC) is the most widely used, due to its excellent mechanical properties (resistance to bending and toughness). However, the durability of these composites has been demonstrated to be critical and alternatives need to be proposed. The used fibers, alkali-resistant (AR fibers, formed by grouping of filaments), are attacked by the aggressive medium imposed by the hydrated cement. An interesting alternative, from a technological point of view, is the incorporation of supplementary cementitious materials of pozzolanic behaviour. The purpose of this research is to study the influence of the different mineral additions in GRC mortars, observing the behaviour of the constituent elements of the material under normal curing conditions and controlled aging processes. Likewise, the behaviour of new composites subjected to different aggressive environments is analyzed, evaluating the durability and improvement of the compounds by determining their mechanical, chemical and physical properties. GRC specimens have been produced through the premix procedure and their mechanical properties (flexural strength, toughness, and modulus of elasticity) have been determined. Additionally, resistance gains have been quantified when comparing GRC composites based on Portland cement (control specimens) with others in which up to 60% of that cement has been replaced by pozzolanic additions. In order to improve the reactivity of pozzolans, in some cases an increase in its fineness has been implemented through grinding (ground fly ash, CVm) or sonication processes (sonicated silica fume, HSS). The GRC specimens have been subjected to an aging process (treatment in water at 55ºC for an extended period) and worsening of the flexural strength and toughness of those who only have Portland cement as cementitious component has been observed. GRC composites containing high amounts of pozzolan (60% CVm) or mixtures of pozzolans (50% CVm / 10% HSS, 50% CVm / 10% FCC) show a substantial improvement in mechanical properties compared to the control GRC. The improvement of these GRC systems with high percentages of reactive pozzolans have been confirmed through physical and physical-chemical studies: evaluation of density, absorption, microscopic studies (magnifying glass and scanning electron microscopy), and thermogravimetric analysis. Regarding the response of GRC composites against different aggressive solutions, the beneficial effect of the presence of pozzolans has been demonstrated. After the exposure of the GRC mortars to a NH4Cl solution, the mechanical behavior of pozzolanic mortars remains above that of the control GRC mortar: this is due to the direct relationship existing with the increase in density and the decrease in the absorption of the composite with the pozzolanic replacement. When evaluating the properties of GRC mortars after exposure to an H2SO4 solution, very important differences are observed in the evolution of the mass, flexural strength and toughness: the control composites are more affected by the acidity of the medium, so that the loss of mass is very significant when compared to the GRCs that present pozzolans. The stay at the Saint Gobain Vetrotex company has confirmed a great similarity to the results obtained by the procedures followed at the UPV laboratory (premixed GRC compounds) compared to the practices developed by the company's materials laboratory (composites of projected GRC). Scalable prototypes have been assessed for the projected GRC industry.
Lalinde Castrillón, LF. (2020). Estudio de compuestos de GRC y adiciones activas: Propiedades mecánicas, envejecimiento acelerado y durabilidad [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/157637
TESIS
Korah, Andrews. "Frontier Urbanization and Affirmative Action in Urban Ghana: A Case of Airport City, Accra." Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1595878309570218.
Повний текст джерелаMeziane, Driss. "Etude de la polymérisation des alcynes amorcée par un dérivé alkylidène du tungstène." Paris 13, 1986. http://www.theses.fr/1986PA132002.
Повний текст джерелаMartins, Carolina Scanavez. "Expressão das proteínas citoesqueléticas actina e tubulina em células osteogênicas cultivadas sobre vidro e vitrocerâmica bioativos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/58/58132/tde-14082012-083511/.
Повний текст джерелаBioactive glasses and glass-ceramics have been successfully applied in various therapeutic strategies to promote the formation of mineralized matrix in bone defects. The exposure of these materials to biological fluids results in chemical and topographical modifications that may affect the interactions of cells with the biomaterial surface, with potential effects on cytoskeletal protein expression and/or organization and cell spreading. The aim of the present study was to evaluate whether changes in the labelling pattern for the cytoskeletal proteins actin and tubulin in osteogenic cells cultured on bioactive Bioglass® 45S5 and Biosilicate® are due to altered mRNA and protein expression levels. Osteogenic cells were obtained by enzymatic digestion of newborn Wistar rat calvarial bone and plated on Bioglass® 45S5, Biosilicate® and borosilicate (bioinert control) for periods of up to 7 days. The following parameters were assayed: i) qualitative epifluorescence analysis of actin and tubulin distribution; ii) quantitative mRNA expression for actin and tubulin by real time polymerase chain reaction (real time PCR); iii) quantitative actin and tubulin expression by enzymelinked immunoabsorbent assay (ELISA), and iv) qualitative analysis of cell morphology by scanning electron microscopy (SEM). At days 3 and 7, cells grown on borosilicate showed typical actin and tubulin labeling patterns of adherent and spread cells on flat, rigid substrates, whereas those on Bioglass® 45S5 and Biosilicate® showed dark areas devoid of fluorescent signals for the cytoskeletal proteins. At the same time points, cultures grown on the bioactive materials showed significant changes in mRNA expression for actin and tubulin, although only slight differences in the amount of actin and tubulin were detected compared with borosilicate. Moreover, a positive correlation between mRNA and protein expression levels as well as a correspondence between epifluorescence imaging and the quantitative data were only detected for cultures grown on borosilicate. SEM analysis revealed that cells cultured on bioactive surfaces were partly or totally covered with material accumulations, whose characteristics resembled the ones for the substrate topography, and which, in some cases, prevented the visualization of the cell limits. In conclusion, Bioglass® 45S5 and Biosilicate® affect actin and tubulin mRNA levels, but not the corresponding protein expression, in osteogenic cell cultures. Thus, the observed changes in the labeling pattern for these proteins should be attributed, at least in part, to the accumulation of materials on the cell surface, likely due to substrate reactions that take place on Bioglass® 45S5 and Biosilicate® when exposed to the cell culture medium.
Arotiba, Omotayo Ademola. "Electrochemical impedance modelling of the reactivities of dendrimeric poly(propylene imine) DNA nanobiosensors." Thesis, University of the Western Cape, 2008. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7669_1266190932.
Повний текст джерелаIn this thesis, I present the electrochemical studies of three dendrimeric polypropylene imine (PPI) nanomaterials and their applications as a platform in the development of a novel label free DNA nanobiosensor based on electrochemical impedance spectroscopy. Cyclic voltammetry (CV), differentia pulse voltammetry (DPV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques were used to study and model the electrochemical reactivities of the nanomaterials on glassy carbon electrode (GCE) as the working electrode.
Fernando, Jesu Delihta Liyaa. "Novel Mesoporous Bioactive Glasses (MBGs) as fillers in dental adhesives « Synthesis, Physico-chemical and biological evaluation »." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1072/document.
Повний текст джерелаImproving the stability of adhesive dentin interface is crucial to extend the longevity of composite restorations. Remineralization through use of ion releasing materials is a promising approach to protect the hybrid layer from hydrolytic and enzymatic degradation. Mesoporous bioactive glasses (MBGs) offer attractive surface features (enhanced surface area and porosity) to use them as fillers in dental adhesives to promote remineralization through ions release. Moreover, the functionalization of pores with antibacterial drugs is a good way to combat secondary caries. The present work focused on the synthesis and evaluation of novel MBGs suitable to be used as fillers in dental adhesives. The MBGs were prepared in an acetate based sol-gel system with industrially safe and non-toxic precursors. MBGs prepared in large scale (50g) offered enhanced surface characteristics in comparison to small scale (10g) MBGs. The investigation on the influence of network modifiers (CaO:Na2O) on the surface characteristics of MBGs revealed that the porosity was driven by CaO content in the composition. Notable, very high surface area (535m2g-1) and pore volume (0.33cm3g-1) was attained in the MBG with highest CaO content. Next, the order of precursor addition effect on the surface characteristics of MBGs has been studied. By Keeping the composition fixed and varying the order of precursor addition during sol-gel synthesis a doubling of surface area, 1.5 times increase in pore volume and 1.2 times decrease in mean pore size was obtained. The demonstrated method is a simple and straightforward route to improve the porosity and homogeneity of MBGs. Furthermore, modulation of mean pore size for a fixed composition is also useful to tailor the pores of the fillers for drug delivery application. With regards to bioactivity, the MBG fillers with highest CaO content had increased calcium phosphate precipitate in SBF after 7 days as opposed to MBG with high Na2O content. Furthermore, all tested samples were non-cytotoxic to Human Gingival Fibroblasts (HGFs) in vitro. Positively, MBGs treated at lower temperature significantly enhanced the metabolic activity of HGFs. Ball milling was employed to reduce the primary particle size of MBG to less than 3μm. Milling seemingly had an adverse effect on the porosity of the MBG filler. Nevertheless, some porosity remained. The commercial adhesive was mixed with 3, 10, 20 and 30 weight percentage of MBG filler. MBG filled adhesive up to10 weight percent filler content had flowable viscosity suitable for adhesive application. The developed MBG with high porosity and CaO content appears as a new step in the development of dental adhesives and also other bioactive dental materials
Maiko, Khumo Gwendoline. "The Isolation and Electrochemical Studies of Flavanoids from Galenia africana and Elytropapus rhinocerotis from the North Western Cape." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5427_1305881229.
Повний текст джерелаIn this study two medicinal plant species, namely Galenia africana and Elytropapus rhinocerotis, the former belonging to the family Aizoceae and the latter belonging to the family Asteraceae, have been investigated and different compounds isolated and characterized. Both species are important plants used in traditional medicine in Africa and particularly in South Africa. Flavanoids are secondary metabolites found in plants. They have a protective function against UV radiation and have a defence against invading illnesses due to their important antioxidant activity. Much of the food we eat and some beverages we drink contain flavonoids. The aim of this study was to investigate the electrochemistry of flavanoids isolated from these species.
Willemse, Chandre Monique. "Nanocomposite-graphene based platform for heavy metal detection." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8123_1323852117.
Повний текст джерелаBerthier, Sébastien. "Complémentarité et représentativité des observations atmosphériques effectuées par instrumentation active et passive sur les nouvelles plates-formes spatiales." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2007. http://tel.archives-ouvertes.fr/tel-00327231.
Повний текст джерелаMatinise, Nolubabalo. "Electrolytic determination of phthalates organic pollutants with n nostructured titanium and iron oxides sensors." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_1177_1305892404.
Повний текст джерелаThis work reports the chemical synthesis, characterisation and electrochemical application of titanium dioxide (TiO2) and iron oxide (Fe2O3) nanoparticles in the determination of phthalates. The other part of this work involved electrochemical polymerization of aniline doped with titanium and iron oxide nanoparticles for the sensor platform in the electrolytic determination of phthalates. The TiO2 and Fe2O3 nanoparticles were prepared by sol gel and hydrothermal methods respectively. Particle sizes of 20 nm (TiO2) and 50 nm (Fe2O3) were estimated from transmission electron microscopy (TEM) The other technical methods used in this study for the characterization of the TiO2 and iron oxide Fe2O3 NPs were SEM, XRD and UV- visible spectroscopy. Cyclic voltammetry, square wave voltammetry and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the nanoparticles. These electrochemical studies of the nanoparticles were performed with a Fe2O3 or TiO2/nafion/glassy carbon membrane electrode in 0.1 M phosphate buffer (pH 7.0) and 0.1 M lithium perchlorate (pH 6.8) under an aerobic condition.
Matyholo, Virginia Busiswa. "Polymeric tyrosinase nanobiosensor system for the determination of endocrine disrupting bisphenol A." Thesis, University of the Western Cape, 2011. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_9288_1319782994.
Повний текст джерелаBoulila, Salha. "Comportement "in vitro" et "in vivo" de verres composites poreux : assimilation osseuse, explorations physiologiques et physico-chimiques." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S105/document.
Повний текст джерелаThe application of biomaterials is increasingly widened. Medical progress suggest the use of biomaterials (bioactive glasses, apatites,..) as implants according to the need of the body. The aim of our work is to highlight the biological influence of organic molecules (bisphosphonates, biopolymers and antibiotics) incorporated into matrix of bioactive glasses. Similarly, our study aims to optimize the best synthesis and combination technique of bioactive glasses to these molecules. The detoxification of male rats strain "Wistar" exposed to nickel chloride by a synthetic apatite also has been the object of this work. Following the bone loss induced, we have demonstrated that the use of antibiotics associated with bioactive glass as bone implants, in ovariectomised rats, eliminates some adverse effects systemic. This has been highlighted by the evaluation of biochemical and histological parameters of liver and kidney. Any significant changes in comparison with those of the negative control was revealed. The in vitro study showed in the one hand that the introduction of Chitosan and especially of the antibiotic in the glass matrix can increase antibacterial activity. This in vitro study showed in the other hand that the Ciprofloxacin induces a negative effect on osteoblastic and endothelial cells. This effect is local when it has been an in vivo experiments. This is highlighted by the oxidative status evaluation. Markers of bone turnover, bone histology and physicochemical parameters show the retarding effect of this antibiotic on the dissolution of the implant and consequently on its bone formation. Synthesis by sol-gel method causes a more important bioactivity than melting. The bioactivity of elaborated bioactives glasses will differ depending on the molecule introduced. It is reduced in the case of combination of Clodronate and Ciprofloxacin in vitro and in vivo. While, Polyvinyl Alcohol and especially Chitosan modify the kinetic of the bioactivity in vivo. Concerning the hydroxyapatite, we tried to explore its detoxifying effect in rats receiving nickel chloride. Our results showed that nickel induces an oxidative stress in the liver, kidney, spleen and red cell pellet. Physiological disorders were observed in rats exposed to nickel. However, implantation of hydroxyapatite protects rats intoxicated by nickel against its toxic effects by decreasing the stress status. The used biomaterial is effective to correct ferric phosphate balance, protect kidney and liver function, reduce level of bone nickel and correct anemia
Zulaikha, Ellya. "Collaborative learning in the rural Indonesian craft industry." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/79247/1/Ellya_Zulaikha_Thesis.pdf.
Повний текст джерелаWigforss, Tua, and Harriet Lubega. "Det osynliga glastaket : om den låga andelen kvinnliga verkställande direktörer." Thesis, Högskolan i Borås, Institutionen Handels- och IT-högskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17877.
Повний текст джерелаProgram: Civilekonomprogrammet
Sacadura, Mariana Portocarrero Pegado Lemos de Mendonça Oom de. "Adaptive glass pane using shape-memory alloys." Master's thesis, 2015. http://hdl.handle.net/10362/26683.
Повний текст джерелаShinki, Masaya. "Characterizing a new and novel glass plate sampler for collection of oceanic microlayers." Thesis, 2011. http://hdl.handle.net/1828/3601.
Повний текст джерелаGraduate
Chen, Keng-Ku, and 陳畊谷. "Design and Control of an Active Air Bearing Table for Flat Panel Display Glass Subtrate." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/70210649319426280673.
Повний текст джерела國立臺灣大學
工程科學及海洋工程學研究所
97
The objective of this thesis is to develop an air bearing table with active control for the floating altitude of the glass substrates of TFT-LCD or solar energy. The principle of an air bearing table is to input the high pressure air to the air bearing blocks on which there are small orifices to spurt the high pressure air such as to form an air cushion between the air bearing and the glass. The lifting force to the glass can be formed by using the difference in pressure between the air cushion and the atmospheric pressure such that the glass substrates can float on the air bearing table and don’t contact the air bearing table directly. Hence, it can reduce the friction between the glass substrates and the air bearing table in compared with the conventional roller conveyors. The study first derives the nonlinear time-variant mathematical models of pneumatic system and then simplify the models for a 3rd system. In the controller design, Fourier series-based adaptive sliding-mode controller with tracking performance is used. To ease the adverse effects caused by approximate errors, unmodeled dynamics and disturbances prior to constructing the control input , the tracking design technique and the Fourier series-based functional approximation technique are incorporated into the sliding-mode control method. Bedsides, this study also analyze the deformation of the glass substrates on the different arranged air bearing table in the steady state for ensuring better air bearing effects and less deformation of glass substrates. Then, the dynamic simulation of overall air-bearing table is implemented for confirming the feasibility of the developed systems. Finally, practical experiments, including position step response, path tracking control of the floating altitude of the glass substrates are perfromed for the verifying the control performance, stability and robustness of the developed system.
Lu, Yi-Chi, and 盧翌綺. "Metallic-Glass Nanotube Arrays as a Surface- Enhanced Raman Scattering (SERS)-active Substrate for Crystal Violet Adsorption." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/y8chn7.
Повний текст джерела國立臺灣科技大學
材料科學與工程系
107
Surface-enhanced Raman scattering (SERS) is a way to significantly increase the intensity of Raman signals of the material molecules adsorbed on the surface, which is widely used in molecular analysis applications, medicine, and environmental engineering. Recently, many kinds of literature have used different metal substrates to increase the surface area and roughness to realize signal enhancement. Therefore, in this study, lithography was used in the patterning of a contact-hole array to fabricate a regular nanotube array by sputter-depositing a coating of metallic glass. The resulting metallic glass nanotube (MGNT) array possesses 1,600,000,000 individual nanotubes on a 5 mm^2 area with the hole diameter was ~650 nm, and height was ~650 nm. Moreover, metallic glasses with the disordered atomic structure have unique mechanical and chemical properties. Compared with the crystal metal, amorphous metallic glasses have no scattering at grain boundaries. In this study, the dielectric constants were first investigated as the selection of SERS substrates of nine systems of thin film metallic glasses (TFMGs). After that, we successfully fabricated five systems of MGNTs arrays such as Ni- (Ni38.5B1.0Si52.7Cr2.1Fe5.7), Ti- (Ti38Zr10.3Cu37.4Nb6.6Co7.7), Cu- (Cu48Zr42Al6Ti4), W- (W82.9Ni9.9B7.2), and Pd- (Pd73.8Cu12.5Si13.7) based MGNTs. Pd-based TFMG is selected as the SERS substrate because it is a noble metal and has a negative dielectric constant. In the experiment, the crystal violet (CV) is selected for probe molecule for its large Raman cross-section. There are two sets of samples (with and without DI water rinse) in order to effectively determine the adsorption of CV molecules on the metallic glass nanotubes. It is discovered that the limit of detection of CV solution are 10^-10 M and 10^-11 M, respectively, with and without water rinse. These are more sensitivity than Si substrate and TFMG, and the enhancement factor is 6.39 × 10^8. This can be attributed to the surface roughness of MGNT is 207 nm much higher than 0.428 nm of TFMG. Thus, it provides more CV molecule adsorption area. In addition, with DI water rinse, the samples were examined by SEM before and after immersing in CV solution with water rinse at exactly the same five locations. The increment in wall thickness is ~33% for 10^-3 M, and decreases of the CV concentration to 10^-10 M is ~22%. The increase in wall thickness is mostly due to the adsorption of CV molecules on the outer wall. However, the negligible increment of ~7% for 10^-11 M is considered to be within experimental error and insignificant in Raman signal. Therefore, the quantitative relationship between the amount of CV adsorption and Raman enhancement was confirmed. Moreover, CV adsorptions without water rinse are also discussed in the appendix. The increment in wall thickness is ~63% for 10^-3 M, and decreases of the CV concentration to 10^-10 M is ~23%. However, the wall thickness increases ~20% for 10^-11 M, which is more significantly different from that of with water rinse. Cross-sectional FIB-prepared TEM observations have been carried out to further characterize the CV-adsorption on the wall of nanotube, confirming the presence of CV molecules on the outer wall. Moreover, the simulation results and Raman mapping were confirmed the existence of hot spots in MGNTs. The EM field strongly enhances in the top of nanotube arrays and gradually decreases to the nanotube gaps. Overall, MGNTs not only provide the large surface area to enhance the Raman signal, but also allow us to quantify the adsorption of CV molecules. In this study, macromolecule folic acid (FA) was also selected for a comparison study. The limit of detection in this case was 10^-7 M. It thus is further confirmed that metal glass nanotube arrays can be effectively applied to the two different types of molecule adsorption for SERS applications.
Hsiao, Yu-Cheng, and 蕭宇成. "Mesoporous Bioactive Glass Acting as a Desensitizing Agent in Dentinal Tubule Occlusion." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/57385074191187489042.
Повний текст джерела高雄醫學大學
香粧品學系碩士班
100
In recent studies, sealing of exposed dentinal tubules is generally considered as one of effective strategy to treat dentin hypersensitivity. Mesoporous bioactive glass (MBG) is a potential material for treating dentin hypersensitivity due to its excellent biocompatibility and osteoconductivity. In this study, MBG powder preparation by sol-gel method mixed with different calculate ratio of phosphoric acid (PA) was applied on the dentin specimen. We used X-Ray Diffractometer (XRD), Scanning electronic microscope (SEM), and Fourier Transform Infrared (FTIR) to investigate the crystallite phase and surface topography of MBG agents, the occlusion ability of dentinal tubules, and the interatomic bonding. The results showed that the major crystallite phase of MBG agents was monocalcium phosphate monohydrate (Ca(H2PO4)2•H2O). MBG paste, mixed from 30% and 40% PA, had the ability to create the penetrate depth greater than 80 µm. These results showed that MBG paste mixed with phosphoric acid solution have a great ability for occluding dentinal tubules; it has short reaction time and good operability, and these agents have potential for the treatment of dentin hypersensitivity.
Ramlall, Nirala. "The barries that inhibit woman from breaking the glass ceiling in the South African public service." Thesis, 2007. http://hdl.handle.net/10321/2009.
Повний текст джерелаThe end of the apartheid era in South Africa presented the new government with a myriad of challenges. This involved massive transformation, whilst ushering in a regulatory framework of enabling legislation to give effect to the country's fledgling Constitution. One of the transformational priorities was to address gender equality. Despite legislative imperatives having been instituted, gender equity targets are not being met, nor are affirmative action programmes being implemented to their fullest to facilitate and support gender equality. This research investigates the barriers that inhibit women from breaking the glass ceiling in the South African public service. The research paradigm was exploratory, using qualitative techniques and the results are largely descriptive. Secondary information was obtained from literature and information available. Multiple case studies were conducted using five subjects who were representative of the target population. The overarching purpose of this study was to investigate and understand the barriers that inhibit women from breaking the glass ceiling in the South African public service. The concept of the glass ceiling is defined as the invisible barrier that blocks women from advancing to senior management positions. The study proposes and considers various issues that may have an impact on upward mobility for women. A review of literature reveals that barriers exist as a worldwide occurrence and these prevent women from upward mobility. Justification for this research is twofold: there has been no such study to date; and gender equality is not being achieved and affirmative action programmes have not been fully implemented. The findings of the study provide a deeper understanding of the barriers that prevent women from career progression in the South African public service. Recommendations are made to address this issue
M
Ngqongwa, Lundi Vincent. "Electrochemical characterization of nanostructured SnO2 and TiO2 forpotential application as dielectric materials in sulfonated-polyaniline based supercapacitors." Thesis, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3398_1306923514.
Повний текст джерелаIn this research project, nanostructured composites based on Tin dioxide (SnO2) and Titanium dioxide (TiO2) with poly-4-styrene sulfonic acid (PSSA) doped polyaniline (PANI) conducting polymer has been investigated based on their structural, electrical and electrochemical properties. The synthesis of conducting polymers and their metal oxide or composites have been carried out chemically or electrochemically according to methods modified from the literature. Layer-by-layer construction of nano-Metal Oxide/PSSA doped polyaniline composites were successfully constructed by electroanalytical methods on the surface of a glassy carbon working electrode (GCE).
Lopes, Carla Filipa Neves. "Caracterização do Comportamento de Vigas de Vidro Estrutural Sujeitas a Solicitação Térmica." Master's thesis, 2016. http://hdl.handle.net/10316/98903.
Повний текст джерелаNos últimos anos tem-se verificado um aumento significativo da utilização do vidro na arquitetura. Este aumento deve-se não só às suas extraordinárias vantagens estéticas e arquitetónicas, ao seu potencial em termos de eficiência energética, como também aos diversos avanços tecnológicos, que têm permitido a utilização deste material, com um aproveitamento cada vez mais eficaz, das suas propriedades resistentes. De entre os referidos avanços tecnológicos destaca-se o tratamento térmico e a técnica de laminação. Esta última consiste em unir dois ou mais painéis de vidro por intermédio de uma película intercalar adesiva. A película de laminação mais recente e com melhor comportamento estrutural é o SentryGlas®. No entanto, dadas as propriedades viscoelásticas da referida película, o seu comportamento é significativamente afetado pela temperatura. A gama de temperaturas onde se verifica redução da sua capacidade resistente corresponde a valores facilmente atingíveis em zonas de clima temperado, numa posição não ventilada de uma fachada de um edifício corrente. Apesar da importância deste facto, até à data, ainda não existe formulação de dimensionamento ou disposições regulamentares para ter em conta este efeito explicitamente no cálculo de elementos de vidro estrutural. Por esta razão é necessário estudar não só a influência da temperatura no comportamento deste tipo de elementos, como também investigar métodos de reforço, que minimizem este efeito penalizador. Exemplo de tal é a introdução de sistemas de pré-esforço. A presente dissertação enquadra-se nesta problemática, pretendendo avaliar e caracterizar o comportamento de vigas de vidro estrutural, laminadas com SentryGlas®, quando sujeitas a ações térmicas. A caracterização é feita à custa de ensaios experimentais, à escala real, com e sem sistema de pré-esforço, em esquema de flexão em quatro pontos. As temperaturas estudadas foram 50ºC e 80ºC, para além da temperatura ambiente que serviu de referência. Deste modo foi possível avaliar não só o efeito da temperatura, como quais as vantagens da introdução de um sistema de pré-esforço neste tipo de elementos estruturais. As conclusões foram estabelecidas com base na comparação dos resultados obtidos experimentalmente, onde se comprovou a eficácia do sistema de pré-esforço e o dano devido à ação térmica, em particular na fase pós-rotura. O trabalho efetuado encontra-se no âmbito do projeto S-Glass: Desempenho Estrutural e Regras de Projeto de Vigas de Vidro Reforçadas Externamente; PTDC/ECM/116609/2010; relativamente às tarefas realizadas na Universidade de Coimbra
In recent years, there has been a significant increase in the use of glass in contemporary architecture. This is due not only to its extraordinary architectural and aesthetic advantages, its potential in terms of energy, as well as due to several technological developments that allowed the use of glass as a load bearing material. Among those technological advances stands out the heat treatment and the lamination technique. The latter consists of two or more glass panes that are bonded by means of an interlayer. One of the latest developed interlayer material that features a better mechanical behaviour is the SentryGlas®. Although since the interlayer is a viscoelastic material its characteristics are significantly affected by temperature. The referred downgrading due to temperature is noticeable at relatively low temperatures easily attainable due to light exposure, in temperate climate, and on an unventilated position of a façade on an ordinary building. In spite of that, the effect of temperature on the laminated compound is not yet fully characterized and there are no code guidelines concerning this aspect. For this reason further studies on the effect of temperature are needed as well as the investigation of reinforcement techniques for structural glass elements that may minimize the negative effects of the temperature on the interlayer. Example of such is pre stressed solution. The present study addresses those topics on an experimental approach, considering full-scale beams with SentryGlas®, with and without pre-stressed system, on an upright position, at a four point bending layout, and subjected to different temperatures. The temperatures considered were 50ºC, 80ºC and room temperature as reference. The thermal load was applied by mean of a thermal chamber especially built and optimized for this purpose. It was thus possible to evaluate not only temperature effects but also the advantages of a pre-stress system, in particular in the post-breakage regime. Conclusions are based on a comparison established between experimental results, which proved the effectiveness of the pre-stressed system and the damage due to thermal load, in particular in post-breakage regime. The research is within the framework of the research project S -Glass: Performance and Structural Beam Draft Rules of Glass Reinforced Externally; PTDC/ECM/116609/2010; concerning the tasks carried out at the University of Coimbra.
Skalová, Štěpánka. "Vývoj nových elektrochemických metod s využitím různých membránových materiálů pro sledování vybraných protinádorových léčiv a fytochelatinů." Doctoral thesis, 2019. http://www.nusl.cz/ntk/nusl-405532.
Повний текст джерелаMedina, Pinto Brayan Orlando. "A utilização de resinas iónicas em odontopediatria: revisão narrativa." Master's thesis, 2021. http://hdl.handle.net/10284/9653.
Повний текст джерелаComposite resins have undergone modifications through the introduction of bioinductive materials in their matrix, such as bioactive glass (BAG) microparticles. Composites containing this type of material are called ionic resins, allowing an exchange of ions between the restorative material and dental tissue. Ionic resins are a new material that combines the physical properties of composites and bioactive characteristics of glass ionomers, namely the release of fluoride ions in greater quantities than Glass Ionomer cements and additionally also release calcium and phosphate ions. In Pediatric Dentistry, this allows a decrease in the execution of more invasive treatments, duo to its bioactive characteristics that can stimulate the production of tissue and improve the quality of the remaining tissue. This bibliographic review aims to address the importance of restorative materials in dentistry and the way in which their characteristics have been improved addressing current needs, improving aesthetics, mechanics, and biocompatibility.