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Dissertations / Theses on the topic 'Inert material'

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Published: 4 June 2021
Last updated: 18 February 2022

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1

Bradley, Gareth Richard. "Fatigue properties of metal inert gas and friction stir welded aluminium alloy 5383-H321." Thesis, University of Plymouth, 2003. http://hdl.handle.net/10026.1/2359.

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The following dissertation details the development of a simple defect-tolerant based model for determining the fatigue properties of a 5383-H321 aluminium alloy and metal inert gas and friction stir welded butt joints in the same alloy. The model considers the fatigue life to consist of three regimes, crack initiation and short and long crack growth, in contrast to the typical defect-tolerant approaches which only consider the long crack growth period. Crack initiation was considered to consist of an initial short crack, present prior to fatigue loading, identical in length to the crack initiator. The short crack growth rate was considered to be a function of the crack length and stress amplitude, whilst the long crack growth regime was described through the Paris equation, dcldN = C(AK)m. The model also considers the effect on the crack initiation and growth rates of the microstructure, macrostructure and residual stresses, with the latter being determined both through the conventional hole-drilling approach and the emerging technique of synchrotron strain scanning. The accuracy of the model was verified through integration of the short and long crack growth regimes, with the predicted lifespan being compared to results obtained from S-N testing of identical welded specimens. A good correlation between the experimental and theoretical results was observed for the parent material and friction stir welded joints for lives in the region 105-106 cycles, although the approach, in its current format, appeared less suitable for determining the fatigue properties of the MIG welded joints. 2
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2

Andersson, Oskar. "Avskiljning av inert material från avfallsbränsle : En fältstudie av förbättrad RDF-produktion på bränsleberedningen i Västerås." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-35780.

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Samtidigt som världens energiproduktion till stor del baseras på förbränning av fossila bränslen behandlas enorma mängder avfall genom deponering. Ökad energiåtervinning av avfall kan bidra till att minska världens utsläpp av växthusgaser. Då avfall bör ses som en resurs är det dock viktigt med en effektiv energiåtervinning. Förbränning i fluidbäddspanna möjliggör god förbränning och hög verkningsgrad men kräver ett finfördelat avfall med lågt innehåll av inert (icke brännbart) material, så kallat RDF. Därför behöver avfallet beredas innan förbränning. En effektiv och välfungerande beredning av avfallsbränsle möjliggör resurseffektiv avfallshantering av utsorterade fraktioner samt effektiv förbränning genom hög bränslekvalitet. Mälarenergis panna 6 på kraftvärmeverket i Västerås är en avfallseldad CFB-panna med bränsleeffekt på omkring 170 MW, vilket motsvarar omkring 50 ton avfall per timme. På den tillhörande bränsleberedningen produceras avfallsbränsle, RDF, i tre beredningslinjer genom att avfallet krossas och olika typer av inert material avskiljs och bildar rejekt från anläggningen.  Magnetisk metall avskiljs med magnetavskiljare, icke-magnetisk metall avskiljs med virvelströmsavskiljare och en tungfraktion bestående av bland annat sten och glas avskiljs med vindsikt. Kvaliteten på avskiljningen är dock bristfällig vilket leder till högt innehåll av inert material i bränslet och högt innehåll av brännbart material i de avskilda fraktionerna. Dessa två problem orsakar kostnader och miljöpåverkan som skulle kunna minskas. Syftet med detta examensarbete var att undersöka vilka faktorer som påverkar avskiljningen av inert material från avfallsbränsle för förbränning i fluidbäddspanna samt ge förslag på åtgärder som kan leda till förbättrad avskiljning. Detta har undersökts genom en fältstudie på den aktuella bränsleberedningen. För att insamla kunskap om bränsleberedningsprocessen och problembilden genomfördes en kartläggning av avskiljningen. Utifrån detta identifierades faktorer som kan påverka avskiljningen. För att ytterligare undersöka vad som påverkar avskiljningsprocessen genomfördes ett antal provtagningar av avskiljningen. En anpassad metod för provtagning av kvaliteten på avskiljningen genom plockanalys togs fram. Sammanlagt genomfördes nio provtagningar under olika förutsättningar. En ny typ av vindsikt testades också för att undersöka hur en investering skulle kunna förbättra avskiljningen. Vindsikten testades utifrån två alternativ av placering. Utifrån resultatet av kartläggningen identifierades fem faktorer som tros påverka avskiljningen. Dessa faktorer är det inkommande avfallet och dess egenskaper, materialflödets storlek genom produktionslinjen, ojämnt materialflöde genom magnetavskiljaren, tillbakakastande turbulens i vindsikten och fastnande material på spjället i vindsikten. Resultatet från de genomförda provtagningarna av kvaliteten på avskiljningen bekräftar att det inkommande avfallet samt materialflödets storlek genom produktionslinjen tros ha stor påverkan på samtliga avskiljare. Då den nya typen av vindsikt testades för att placeras i beredningslinjen visades ingen utmärkande förbättring jämfört med de befintliga vindsiktarna. Då den testades som andra steget i en två-stegs vindsiktning visade däremot resultatet potential att uppnå förbättrad avskiljning. Resultatet visade att två-stegs vindsiktningen har potential att minska mängden tungfraktionsrejekt med cirka 30 – 50 %. Det inerta innehållet i utgående lättfraktion var dock 6 – 8 % vilket motsvarar en höjning av det inerta innehållet i den totala mängden RDF på cirka 0,5 procentenheter. Dock medför en två-stegs vindsiktning att mer material kan siktas ut i vindsiktarna i beredningslinjerna vilket därmed skulle kunna ge en minskning av den totala mängden inert material i RDF. Som slutsats dras att investeringen i ny vindsikt för att skapa en två-stegs vindsiktning skulle kunna ge förbättrad avskiljning. Den nya vindsikten kan med fördel efterföljas av ytterligare avskiljning eftersom mängden inert material i RDF är relativt koncentrerat där. Dock bör en vidare utredning om kostnader och besparingspotential genomföras innan investeringen kan föreslås som åtgärd. Två typer av enklare konstruktioner föreslås för att åtgärda tre av de faktorer som identifierats. En konstruktion för att jämna ut materialflödet innan magnetavskiljaren samt en konstruktion för att förändra luftflödet i vindsikten. Att minska materialflödet genom linjerna föreslås som en viktig åtgärd för att förbättra avskiljningen. Detta kan åstadkommas genom att fördela RDF-produktionen så jämnt som möjligt på produktionslinjerna samt att sprida ut produktionen jämnt över tid. Detta kräver en mer aktiv planering av produktionen samt minimering av stopptider. En viktig slutsats som har dragits är att det inkommande avfallet varierar kraftigt och har stor inverkan på avskiljningsprocessen. En åtgärd som föreslås för att ge förbättrad avskiljning är att en regelbunden kontroll och variation av processen bör införas. Detta föreslås ske genom uttag och kontroll av RDF och rejekt från beredningslinjerna tillsammans med en bedömning av det inkommande avfallet. Informationen bör sedan ligga till grund för ett beslut om hur processen ska styras för att säkerställa en stabil kvalitet på avskiljningen.
Energy recovery of waste got huge potential of decreasing the greenhouse gas emissions in the world. Combustion in fluidized bed boilers gives high resource efficiency but demands a comminuted fuel with low content of inert (non-combustible) materials, a so called refuse derived fuel (RDF).  A well-functioning separation process as part of the RDF-production allows efficient combustion as well as efficient treatment of the separated materials. The purpose of this degree project is to investigate what factors that influences on the separation of inert material from waste for combustion in a fluidized bed boiler and how the separation can be improved. This is investigated through a field study of a fuel-preparation plant in Sweden. The separation process has been examined visually and by experiments based on sampling and manual sorting of waste fractions. The results show five factors that are assumed to influence on the sorting. Three of them are suggested to be solved by simple constructions. One factor that shows to have a great impact is the input waste to the process which is varying to a large extent. A measure that is suggested to give improved separation is a recurrent check of the RDF quality and the reject quality. Combined with information about the input waste this should be basis for recurrent adjustments of the plant to achieve a more stable quality of the separation output. Another measure that is suggested is to decrease the size of the material flow through the production line. This is suggested since the size of the flow is assumed to have an important impact on the separation. The decrease can be achieved by more evenly distribute the production over time and over the production lines. This will though require a more active planning of the production and minimization of production stops. As part of the work a new wind sifter has also been tested.  The wind sifter show good potential of improving the separation if it would be installed to create a two-step wind sifting. However, since the investment of a new wind sifter implies a high investment, a study of the costs and saving potential is required before the investment can be suggested as a measure.
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3

Gmitter, Andrew J. "The influence of inert anode material and electrolyte composition on the electrochemical production of oxygen from molten oxides." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44211.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 109-116).
Shifts in global and political climates have led industries worldwide to search for more environmentally sound processes that are still economically viable. The steel industry is studying the feasibility of molten oxide electrolysis, a novel process by which molten iron and gaseous oxygen are the products; no carbon dioxide is produced at the site of the electrolysis cell. The research presented in this thesis focuses on the anodic reaction and the preliminary development of an inert anode, as well as investigations into the mechanism of the oxygen evolution reaction. Various elements have been considered with the platinum group metals possessing the best combination of physical properties to serve as the inert anode. Cyclic voltammetry at 1575°C was used to compare the candidates. Iridium yielded the highest current density at a given overpotential followed by rhodium and platinum regardless of the composition of the electrolyte. Speculation as to metal oxide intermediate phases formed and mechanisms for the oxygen evolution reaction are discussed. Notably, the basicity of the molten aluminosilicate electrolyte was found to greatly influence the rate of oxygen gas evolution as evidenced by the linear dependence of the current density on optical basicity. This is crucial for the design of a full-scale electrolysis cell as improved kinetics of the anodic reaction will yield higher throughput and/or enhanced power efficiency. Combining our finding of the relationship between current density and basicity with previous authors' contributions on the effect of partial pressure of oxygen, we argue that to a first approximation, the magnitude of the current density is governed by the concentration of free oxide ions and by the partial pressure of oxygen in the headspace above the melt.
(cont.) Lastly, to, in part, address the disparate natures of the interests of steelmakers, glassmakers, geochemists, and electrochemists, the difficulties in performing electrochemical measurements at extremely high temperatures (~1600°C), and the absence of a comprehensive review of the last sixty years of work on oxygen evolution from molten silicates, this thesis is intended to serve as an essential guide for future work in this field.
by Andrew J. Gmitter.
S.M.
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4

Soares, Diego. "Estudo experimental da produção de fuligem em chamas laminares." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/141152.

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Sérios problemas ambientais têm origem em processos de combustão incompletos. Entre os produtos indesejados está a fuligem, considerada como um dos principais fatores da mudança climática observada nos último anos. Desta forma, ferramentas para diagnóstico da emissão de material particulado se fazem necessárias. Com o advento do laser, o desenvolvimento de técnicas óticas não intrusivas teve início. Dentre elas, destaca-se a técnica denominada incandescência induzida por laser (laser induced incandescence – LII), a qual pode gerar resultados resolvidos no espaço para a fração volumétrica de fuligem. Neste contexto, este trabalho apresenta um estudo experimental sobre a produção de fuligem em duas situações: na primeira, foram estudadas chamas laminares pré-misturadas de etileno e ar aplicando-se a técnica LII. Os resultados foram calibrados a partir da fração volumétrica de fuligem média empregando a técnica de extinção de luz, obtendo-se, então, resultados quantitativos espacialmente resolvidos da fração volumétrica de fuligem. A utilização de diferentes gases no escoamento anular também foi avaliada. A segunda situação abordada envolve o estudo de chamas laminares não pré-misturadas utilizando o gás natural como combustível. O impacto da diluição de inertes em diferentes proporções sobre a fração volumétrica de fuligem em diversas alturas da chama foi estudado por meio da técnica LII. Os resultados obtidos foram comparados à outros resultados presentes na literatura e servirão como validação de futuros modelos de formação de fuligem.
Serious environmental problems are assigned to incomplete combustion processes. Among the unwanted products, soot can be related as an important factor of climate changes observed in the last years. Thus, particulate material emissions diagnostic tools are necessary. Due the laser advent, the development of non-intrusive optical techniques was possible. One of the most importante technique is the laser induced incandescence, LII, which can generate spatially and temporally resolved results of soot volume fraction. In this context, an experimental study regarding the soot production was developed in two different situations: in the first one, premixed laminar flames of ethylene and air were investigated by applying the LII technique. The results were calibrated through the average of soot volume fraction results obtained by the light extinction technique. Therefore, it was possible to obtain quantitative results of spatially resolved soot volume fraction. Different gases employment at the annular flow were also evaluated. The second situation studied involves the analysis of natural gas laminar non-premixed flames. The impact of different inert gas dilution ratio on the soot volume fraction at different heights of the flame was evaluated by the LII technique. The results were compared to other authors and will serve as validation for future soot formation models.
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5

Riggs, Mark R. "TIG Welding of Nickel Titanium to 304 Stainless Steel." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397607979.

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6

Hessling, Oscar. "Influence of Oxygen Partial Pressure on the Droplet Shape of Stainless Steel Using Levitated Droplet Method." Thesis, KTH, Materialvetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199668.

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An induction setup for levitation studies of molten metals was built. The setup was used to levitate and heat stainless steel samples of 2.00 g to 1600 °C and subject them to different atmospheres. Changes in shape and temperature were recorded by video and infrared thermocouple. Oxide films forming on the droplets during levitation were observed. It was possible to notice an immediate surface reaction when the reaction gas was introduced. This reaction is concluded to influence the surface and bulk composition, and therefore have an effect on the shape evolution of the droplet. A more oxidizing atmosphere resulted in a more conical droplet shape; this is thought to be an effect of lowered surface tension and the conically shaped volumetric force caused by the magnetic field. Changes in temperature after the sample is molten are thought to be an effect of changes in emissivity, caused by surface oxidization. Post mortem analysis show a difference in surface morphology for samples subjected to different gases, as well as a difference in amount of oxidization.
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7

Meyer, Pauline. "Mécanismes de dégradation d’anode de type cermet pour la production d’aluminium." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30224.

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La thèse s’inscrit dans le cadre d’un projet de recherche visant à élaborer une anode permettant le dégagement d’oxygène en milieu de cryolithe fondue à 960°C et dont l’utilisation supprimerait les émissions de dioxyde de carbone du procédé de production d’aluminium Hall-Héroult. Le type d’anode envisagée est un composite Cermet (CERamique – METal), généralement constitué d’une phase métallique à base de nickel, cuivre et fer et d’une ou plusieurs phase(s) oxyde(s) conductrice(s) du type NixFe3-xO4 et Ni1-xFexO. Deux types de cermet, biphasé et triphasé, ont été étudiés dans le cadre de ce projet. L’objectif principal a été de comprendre les mécanismes de dégradation de telles anodes durant les électrolyses. Les cermets ont été testés sous une densité de courant de 0,80 A/cm² pour différentes durées, puis analysés par microscopie optique et microscopie électronique à balayage couplée à une analyse dispersive en énergie. Les premières électrolyses, effectuées dans un électrolyte synthétique, sans aluminium métallique et sous atmosphère argon ont révélé à la fois une dégradation chimique et électrochimique. L’étude de la dégradation chimique a été réalisée grâce à des immersions dans l’électrolyte sans polarisation. Les résultats ont mis en évidence une dissolution de la phase spinelle, liée à un phénomène de substitution entre les ions Al3+ de l’électrolyte et Fe3+ du spinelle, entrainant la formation d’un aluminate du type NixFe3-x-yAlyO4. Lorsque x = 0 et y proche de 2, la phase spinelle est dissoute alors que lorsque x est proche de 1, la phase spinelle est stabilisée et sa dissolution ralentie. Les électrolyses menées jusqu’à la fin de vie des matériaux ont révélé l'attaque préférentielle de la phase métallique pour former des composés fluorés et oxydes. Grâce aux caractérisations micrographiques et aux calculs thermodynamiques (logiciel FactSage 7.1), un mécanisme de dégradation global des anodes a été proposé. La compréhension des mécanismes de dégradation chimique et électrochimique des matériaux a permis de proposer des voies d'amélioration concernant à la fois le matériau d'anode et la chimie du bain cryolithique
The thesis is a part of a research project which develop an anode permitting the release of oxygen in molten cryolite medium at 960°C, in order to eliminate carbon dioxide emissions from the aluminium production process called Hall-Héroult process. The type of anode envisaged is a Cermet composite (CERamic - METal), generally consisting of a metallic phase based on nickel, copper and iron and one or more conductor oxide phase(s) such as NixFe3-xO4 and Ni1-xFexO type. Two types of cermet, two-phase and three-phase, have been studied in this project. The main objective was to understand the degradation mechanisms of such anodes during electrolysis. The cermets were tested at a current density of 0.80 A/cm² for different durations and analyzed by optical microscopy and scanning electron microscopy coupled with dispersive energy analysis. The first electrolyses, carried out in a synthetic electrolyte, without metallic aluminum and under argon atmosphere revealed both chemical and electrochemical degradations. Study of chemical degradation was carried out thanks to immersions in the electrolyte without polarization. The results showed a dissolution of the spinel phase, linked to a substitution phenomenon between the Al3+ ions from the electrolyte and Fe3+ from spinel, resulting in the formation of a NixFe3-x-yAlyO4 aluminate type. When x = 0 and y close to 2, the spinel phase is dissolved whereas when x is close to 1, the spinel phase is stabilized and its dissolution slowed down. Electrolyses conducted to the end of life of the materials revealed the preferential attack of the metal phase to form fluorinated compounds and oxides. Thanks to micrographic characterizations and thermodynamic calculations (FactSage 7.1 software), a global degradation mechanism of the anodes has been proposed. The understanding of the chemical and electrochemical degradation mechanisms of the materials made it possible to propose ways of improvement concerning both the anode material and the cryolithic bath chemistry
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8

Rivera-Calderon, Reina Laura. "Studies on adherence of staphylococcus epidermidis to inert plastic materials." Thesis, University of Ottawa (Canada), 1985. http://hdl.handle.net/10393/4858.

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9

Gustafsson, Michael. "Light from Dark Matter : Hidden Dimensions, Supersymmetry, and Inert Higgs." Doctoral thesis, Stockholm : Department of Physics, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7345.

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10

Henneke, Michael Ray. "Simulation of transient combustion within porous inert media /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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11

Rambelli, Patrizio. "Materiali inerti riciclati: sostenibilità del riciclaggio e qualità." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amslaurea.unibo.it/1340/.

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12

Chen, Hsi-Ching B. "Shear localization in high-strain-rate deformation of inert and reactive porous materials /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9732695.

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13

Todt, Andreas. "Beitrag zur Entwicklung neuartiger hybrider Werkstoffverbunde auf Polymer/Keramik-Basis." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-228698.

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Kohlenstofffaserverstärkter Kohlenstoff weist ausgezeichnete thermische, mechanische und chemische Eigenschaften auf. Aufgrund seiner Faserarchitektur und Porosität zeigt dieser eine mit metallischen und polymeren Werkstoffen vergleichbar hohe Schadenstoleranz. Die Herstellung komplexer Leichtbaustrukturen aus C/C-Verbunden ist jedoch zeit- und kostenintensiv. Ein neuer Ansatz stellt die Integration geometrisch simpler C/C-Verbunde in komplexe, problemlos zu realisierende polymere Strukturen dar. Ein derartiges Werkstoffkonzept vereint die Vorteile seiner Komponenten in einem ganzheitlichen Werkstoffsystem. Einen Nachteil stellt jedoch die geringe wechselseitige Adhäsion seiner Komponenten dar. Die Innovation dieses Beitrags stellt sich einerseits der Herausforderung die mechanischen Eigenschaften der C/C-Verbunde in Abhängigkeit der intrinsischen Porosität zu beeinflussen. Dies geschieht durch Veränderung der chemischen und physikalischen Vernetzungsbedingungen des Matrixprecursors. Andererseits soll die dadurch herrührende inhärente Porosität zur Vergrößerung der wirksamen äußeren Oberfläche und zur gezielten Verbesserung der Adhäsion zum Polymer führen. Es wird ein Kohlenstoffprecursor mit variabler offener Porosität entwickelt und daraus neuartige verschiedenporöse C/C-Verbunde hergestellt und untersucht. Im Anschluss werden die verschiedenporösen C/C-Verbunde mit ausgewählten Polymeren unter definierten Konsolidierungsparametern thermisch gefügt und deren wechselseitiges Adhäsionsverhalten bewertet
Fibre-reinforced ceramic matrix composite materials are characterized by excellent thermal, mechanical and chemical properties. Their high tolerance regarding damaging is a result of the intrinsic fibre structure and porosity. Due to this fact, they offer outstanding dampening characteristics, as is the case for polymeric materials. The production of complex structures is very time consuming and expensive. The integration of simple geometric ceramic composite materials in complex polymeric structures is regarded as a new approach for the production of these materials. These easy-to-produce hybrid ceramic/polymer compound materials combine the advantages of ceramics and polymers in one material system. However, one main disadvantage of these materials is the mutual adhesion of the two components. This article deals with the challenge of the manipulation of the mechanical properties of the C/C composites depending on the intrinsic porosity. This is realized by altering the physical and chemical wetting/coating conditions of the matrix precursor. In addition, the inherent porosity is supposed to increase the effective outer surface and specifically improve the adhesion. For this purpose, a novel carbon precursor with an adjustable open porosity is developed and investigated further. During this different versions of the CFRP and various C/C materials of different production steps are produced and examined. The variation of the precursors is supposed to take place in the polymeric state. The different C/C composites are subsequently thermally bonded with selected polymers and defined consolidation parameters. The mutual joining and connection behaviour is investigated further
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14

Lorentsen, Odd-Arne. "Behaviour of nickel, iron and copper by application of inert anodes in aluminium production." Doctoral thesis, Norwegian University of Science and Technology, Faculty of Natural Sciences and Technology, 2000. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-68.

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A thorough investigation was performed on the behaviour of Ni, Fe and Cu oxides dissolved in cryolite melts, and the solubility of these species was measured as a function of alumina content, NaF/AlF3 molar ratio (CR) and temperature. Predominance area diagrams showing the solid phases containing Ni, Fe and Cu, respectively, as a function of the partial oxygen pressure and the alumina activity at 1020 oC were constructed. These diagrams were based on present emf and solubility measurements.

The interpretations of the solubility measurements for the oxides of Ni and Fe gaveconclusive and consistent results. The oxides of Ni and Fe exhibit decreasing solubility with decreasing temperature and with increasing alumina concentration. The Ni(II) concentration decreased from 0.32 wt% in cryolite to 0.003 wt% in alumina-saturated melts, while that of Fe(II) decreased from 4.17 to 0.32 wt% in similar melts. FeO and NiO are stable solid phases at low alumina concentrations, while FeAl2O4 and NiAl2O4 are stable at high concentrations. The alumina concentrations corresponding to the points of coexistence between FeO and FeAl2O4 and between NiO and NiAl2O4 were determined to be 5.03 and 3.0 wt% Al2O3, respectively, corresponding to the following Gibbs energy of formation from the oxide compounds,∆G0fNiAl2o4 = –28.6 ± 2 kJ/mol and ∆G0f FeAl2O4 = –17.6 ± 0.5 kJ/mol.

The solubilities of FeAl2O4 and NiAl2O4 as a function of the CR were investigated in alumina-saturated melts at 1020 oC. For both compounds a maximum solubility was found at CR ~5, being 0.008 wt% Ni(II) and 0.62 wt% Fe(II). The results are discussed with respect to the species present in solution. Both Fe(II) and Ni(II) dissolve as fluorides with different numbers of associated “NaF’s”. Ni(II) seems to form Na3NiF5 in melts with molar ratios 2 to 12, while Fe(II) is present as NaFeF3 in acidic (CR 3–10) melts and as Na3FeF5 and probably some Na4FeF6 in basic melts (CR > 3).

The solubility of both Cu oxidation states Cu(I) and Cu(II) decreases with decreasing temperature. The solubilities of Cu(I) initially decreased with increasing alumina concentration, showing a minimum at a certain alumina concentration followed by an increase. The solubilities were 0.36 wt% Cu(I) and 0.92 wt% Cu(II) in cryolite, and 0.30wt% Cu(I) and 0.45 wt% Cu(II) in alumina-saturated cryolite at 1020 oC.

At 1020 oC the solubilities of Cu2O and CuO were little influenced when changing the CR from 3 to 8 in alumina-saturated melts (~0.30 wt% Cu(I) and ~0.45 wt% Cu(II)), but there was an upward trend for CR < 3. Solubility measurements for CuO in alumina-saturated melts at CR 3.0 to 1.2 clearly showed that the saturation concentration is dependent on both temperature and melt composition.

Copper ions in solution show a complex behaviour, since they form fluorides and oxycomplexes simultaneously. The extent of co-existence of Cu(I) and Cu(II) in the same melt is also considerable, and it is depending on the alumina activity in the melt. According to thermodynamics the stable copper oxide phases at high alumina activities are the aluminates CuAlO2 and CuAl2O4. However, no clear changes in the solubilities were found for the points of coexistence between Cu2O and CuAlO2 and CuO and CuAl2O4, respectively, as was the case for Ni(II) and Fe(II). Although there are uncertainties regarding the thermodynamic data available for the formation of copper aluminates, models for the dissolution mechanisms and for the species present in the melt are suggested. Cu(I) seems to form mainly CuF at low alumina contents, while Na5CuO3 dominates at higher alumina concentrations. Likewise, Cu(II) seems to form CuF2, but the concentration of CuF2 decreases with increasing alumina content. The species that gave the best fit for the cupric oxy-complexes was Na16CuO9, and the amount increased with increasing alumina content.

Cermet anodes were prepared with a NiFe2O4-based oxide phase mixed with a ~20 wt% copper-rich metal phase. The electrical conductivity for these materials was measured as a function of temperature, showing semiconductor behaviour in the temperature range from room temperature to 1050 oC. The highest electrical conductivity measured was ~30 S/cm at 1000 oC, which is on the low side for use as an anode material for aluminium production.

Three cermet anodes were tested by electrolysis for 48 hours. After the experiments the anodes were examined with SEM. There was no metal phase present in the outer 100 µm of the anode, not even pores were observed that could indicate where the metal grains had been. A copper-rich phase was found in one case ~2 mm from the outer surface, and it is believed that copper diffuses out of the anode.

The cermet anodes dissolved slowly in the electrolyte during electrolysis. The steady state concentrations of Fe and Cu in the electrolyte were below the saturation concentrations, while the concentration of Ni was 3 - 4 times above saturation. The dissolution of the anode does not fit a first order mass-transport model, but it can probably be explained by a controlled dissolution mechanism with some additional disintegration/spalling of the anode material. Further work is needed to draw a firm conclusion. In general, correct solubility data for the anode constituents are needed to make a proper evaluation of various anode materials. Perhaps the first order mass-transport model agrees for some materials, but based on the present results it seems untenable for cermet materials made of NiFe2O4 with a copper-rich metal phase.

The solubilities of the oxides of Ni(II) and Fe(III) are very low for the alumina-saturated melt used during electrolysis, which make them promising candidates for inert anodes. However, if nickel aluminate, which is an insulator, is formed and deposited on the anode surface, it is a cause of concern. Fe(II) aluminate is not expected to form on the anode surface, since Fe(III) is the stable oxidation state in the presence of oxygen gas. However, solid Fe(II) aluminate may be formed in the bulk of the electrolyte where the partial oxygen pressure is lower.

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15

Moreira, Edson Adriano 1981. "O problema de Newton : a materia essencialmente inerte versus a evidente atividade na natureza." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/281938.

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Orientador: Fatima Regina Rodrigues Evora
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas
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Resumo: Essa dissertação analisa o chamado "problema de Newton", isto é, o problema de conciliar conceitualmente a inatividade essencial da matéria com a evidente atividade na natureza representada pela força de gravitação universal. Num primeiro momento, temos por objetivo examinar a gênese desse problema e, num segundo momento, os argumentos que Newton desenvolve procurando rebatê-lo
Abstract: This thesis analyses the so-called "Newton's problem", that is, the problem of conceptually conciliating the essential inactivity of matter with the evident activity in nature represented by the universal gravitation force. In a first moment, we are intended to examine the origin of this problem and, in a second moment, the arguments Newton develop in order to solve it
Mestrado
Filosofia
Mestre em Filosofia
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16

Martinez, Sarache Handel Andres 1986. "Avaliação físico-química das cinzas dos resíduos da cultura da mandioca durante a formação de aglomerações com material inerte." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265890.

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Orientador: Waldir Antonio Bizzo
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A tecnologia do leito fluidizado é considerada uma das alternativas que oferece maior eficiência e flexibilidade para o aproveitamento energético de combustíveis sólidos. O material de leito geralmente usado é a areia devido aos seus baixos custos e facilidade de obtenção. Porém, o aproveitamento energético de resíduos agrícolas, que possuem alto teor de álcalis, em reatores de leito fluidizado apresenta um problema relacionado às interações entre o material do leito e as cinzas da biomassa. Este problema é caraterizado pela aglomeração do material contido no interior do leito, o que pode conduzir à perda do estado de fluidização ocasionando paradas não programadas do reator para troca do material. Entre os diversos mecanismos propostos para contra-arrestar a formação de aglomerações, durante a combustão de biomassa, o uso de matérias de leito de baixo conteúdo de sílica e a lavagem prévia da biomassa tornam-se alternativas economicamente viáveis. Através das técnicas de Análise Térmica Simultânea (TG/DTA) e Microscopia Eletrônica de Varredura (MEV) buscou-se avaliar a tendência das cinzas dos ramos grossos da planta de mandioca à formação de aglomerações, como consequência das interações físico-químicas quando estão misturadas com areia a altas temperaturas. Misturas das cinzas com alumina e com dolomita foram testadas a fim de comprovar que reduzem a formação de aglomerações. Também foi estudado o efeito da lavagem simples da biomassa com água. Os resultados obtidos mostraram que ao redor de 770 °C o potássio contido nas cinzas reagiu com a sílica da areia formando eutéticos de baixo ponto de fusão compostos pelo sistema K2O-SiO2, que se depositaram sobre os grãos de quartzo e aderiram as partículas de inerte ao redor, promovendo a formação de aglomerações. Aproximadamente a 900 °C aconteceu a difusão de Mg, Ca e Fe que reagiram com o material depositado formando uma camada adicional de recobrimento, composta pelos sistemas K2O-SiO2-MgO e/ou K2O-SiO2-CaO-Fe2O3, que fortaleceu as uniões formadas entre as partículas de areia aglomeradas. Estes resultados concordam com os mecanismos de formação de aglomerações propostos na literatura
Abstract: The fluidized bed technology is considered one of the alternatives that offer greater efficiency and flexibility for the energetic use of solid fuels. The bed material commonly used is silica sand due to its low cost and ease of production. However, the energetic use of agricultural residues in fluidized bed reactors, often present a problem related to the interactions between the bed material and biomass ashes, which generally have high alkali content. This problem is characterized by the agglomeration of the material contained within the bed, which can lead to defluidization and unscheduled shutdowns of the reactor to change the bed material. Among the different mechanisms proposed to counteract the formation of agglomerations during the biomass combustion, the use of alternative bed materials of low content of silica and water leaching of the biomass, become economically viable alternatives. Simultaneous Thermal Analysis (TG/DTA) and Scanning Electron Microscopy (SEM) techniques were used to evaluate the trends of the ashes produced from cassava branches to agglomerations, as a result of physicochemical interactions when mixed with sand at high temperatures. Different mixtures between ashes with alumina and with dolomite were tested in order to reduce the formation of agglomerations. The effect of leaching the biomass with water was also studied. The results showed that about 770°C, the potassium contained in the ashes reacted with the silica sand particles surface, forming low melting point eutectics governed by the K2O-SiO2 system, which were deposited and adhered to quartz particles around, promoting the formation of agglomerations. Around 900°C took place the diffusion of Mg, Ca and Fe which reacted with the deposited material, forming an additional coating layer composed of K2O-SiO2-MgO and/or K2O-SiO2-CaO-Fe2O3 systems, that strengthened the joints formed between the agglomerated sand particles. These results agreed with the agglomerations formation mechanisms, proposed in the literature
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica
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17

Lago, Milton Luis do. "Laminação em atmosfera inerte de ligas à base de magnésio para armazenagem de hidrogênio." Universidade Federal de São Carlos, 2014. https://repositorio.ufscar.br/handle/ufscar/740.

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Financiadora de Estudos e Projetos
In recent decades, the use of energy presented strong growth due to the need of supplying the daily energy consumption of approximately seven billion people. To solve this problem, it has been investigated the nature, alternative energy sources which respect the environmental issues, to provide social and technological development without negative impacts on the environment. Several processing routes have been investigated in recent years in order to overcome the obstacles of storage and availability of hydrogen as a clean, safe, cost effective and of easy manipulation energy source. The solid state reaction of magnesium and hydrogen gas produces the magnesium hydride compound which provides safe manipulation, high volumetric and gravimetric densities when compared to other traditional forms of storage (liquid or gas), coming out to be promising for being used on an industrial scale as energy carrier for mobile application. However, conventional processing routes produce a material which requires the use of high temperatures during cycling, as well as low speed of the kinetics of absorption and desorption of hydrogen gas, which limits its possibility of application. This work aims to improve the properties of magnesium alloys by cold rolling under inert atmosphere. To achieve this goal, it was developed a laminator equipped with speed control of cylinders that has capacity of 1.1 kilowatts, which works inside a glovebox. The equipment allows producing, by severe plastic deformation, voluminous magnesium-bases samples to storage hydrogen gas, under controlled atmosphere in order to avoid the incorporation of gaseous and/or solid impurities usually found on other viii routes of processing. Structural characterization of the processed samples was performed by techniques of analysis of XRD, SEM and TEM. The hydrogen storage properties were evaluated by DSC and measurements of PCT.
Diversas rotas de processamento vêm sendo investigadas nos últimos anos, com intuito de superar as barreiras existentes para o armazenamento e disponibilidade do hidrogênio como fonte de energia limpa, segura, rentável e de fácil manipulação. A reação no estado sólido de magnésio e gás hidrogênio forma o composto hidreto de magnésio que proporciona manipulação segura, elevada densidade volumétrica e gravimétrica se comparados a outras formas tradicionais de armazenagem (líquida ou gasosa), tornando-o promissor para uso em escala industrial como portador de energia para aplicação móvel. Entretanto, as rotas de processamento convencionais produzem um material que demanda o uso de temperaturas elevadas durante a ciclagem, assim como, baixa velocidade na cinética de absorção e dessorção de gás hidrogênio, o que limita sua possibilidade de aplicação. Este trabalho tem como meta a busca da melhoria nas propriedades de ligas à base de magnésio através de laminação a frio sob atmosfera inerte. Para atingir esta meta foi desenvolvido um laminador dotado de controle de frequência de rotação dos cilindros com potência de 1.1 quilowatts, que funciona no interior de uma glovebox. O equipamento permite produzir amostras volumosas à base de magnésio para armazenagem de gás hidrogênio, sob atmosfera controlada com intuito de evitar a incorporação de impurezas sólidas e/ou gasosas normalmente encontradas em outras rotas de processamento. A caracterização estrutural das amostras processadas foi executada através das técnicas de análise de DRX, MEV e MET. As propriedades de armazenagem de hidrogênio foram avaliadas por DSC e medidas PCT.
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18

Marou, Alzouma Ousseini. "Durabilité tribologique de matériaux pour insert de dents de tunnelier." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0042.

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La fréquence des opérations de maintenance lors de l’excavation du sol par les tunneliers est problématique pour les entreprises de travaux publics. Ces opérations de maintenance engendrent des temps morts onéreux et nécessitent l'intervention d'opérateurs dans des conditions de travail hyperbares. Une des raisons aux nombreuses interventions humaines pour la maintenance est l’endommagement des outils racleurs du sol excavé (dents) qui sont placés sur la tête du tunnelier. Ces outils sont sujets à l’usure compte tenu de l’abrasivité des différents milieux qu’ils rencontrent. Le but de cette thèse est de contribuer à augmenter d’au moins 20% la durée de vie des matériaux constitutifs de ces outils, afin de réduire les différentes opérations de maintenance qui exposent les opérateurs à des risques importants. Pour atteindre cet objectif, les investigations menées dans ce travail ont porté sur plusieurs axes. Dans un premier temps, une expertise est menée pour identifier les modes d’endommagement prédominants sur les inserts à base de carbure de tungstène placés sur les dents ; ensuite, de nouveaux matériaux avec des propriétés mécaniques et des microstructures optimisées, développés dans le cadre du projet européen NeTTUN, sont caractérisés sur des bancs d’essais représentatifs. Ces essais ont permis de bien comprendre les mécanismes d’usure des nouveaux matériaux à base de carbure de tungstène. Les résultats de ce travail peuvent ensuite donner lieu à de nouvelles orientations en matière de choix de matériaux pour renforcer les dents de tunnelier
The frequency of maintenance operations during the excavation of the ground by the tunnel boring machines (TBM) is problematic for civil engineering companies. These maintenance operations provoke expensive timeouts and they bring in excavation operators in risky hyperbaric work conditions. One of the reasons which leads to the numerous human interventions for the maintenance is the damage of drag bits located on the cutting wheel of the TBM. These drag bits undergo wear due to the abrasiveness of the various media they meet. The purpose of this thesis is to contribute to increase by 20 % at least the lifetime of the materials of the dag bits, in order to reduce the various maintenance operations which expose the operators to important risks. To achieve this goal, the investigations led in this work concerned several axes. At first, an expertise is led to identify the wear modes prevailing on the carbide inserts located on the drag bits; then, new materials with enhanced mechanical properties and optimized microstructures, developed in the framework of the European project NeTTUN, are characterized on representative lab testing devices. These tests allowed us to understand well the wear mechanisms of the newly developed grades of tungsten carbides. The results of this work can lead to new strategies for the selection of materials to reinforce the drag bits
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19

Garcia, Marcelo Loureiro. ""Avaliação do material suporte no desempenho de reator anaeróbio operado em bateladas seqüencias aplicado ao tratamento de esgoto sanitário"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-18042006-160458/.

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O projeto proposto teve como objetivo principal à avaliação do suporte no desempenho do reator anaeróbio operado em bateladas seqüenciais, com agitação, contendo biomassa imobilizada no tratamento de esgoto sanitário do Campus da USP em São Carlos. O estudo do desempenho global deste tipo de configuração de reator é extremamente vinculado com o suporte inerte o qual proporciona a aderência e crescimento da biomassa. Neste trabalho foram estudados três suportes inertes: espuma de poliuretano, carvão vegetal e polietileno de baixa densidade reciclado. A avaliação global foi realizada sob análise de três diferentes e dependentes variáveis locais: o desempenho do reator, a análise cinética e os exames microbiológicos. A espuma de poliuretano pôde ser considerada como sendo o material mais adequado para tal finalidade, apresentando maiores eficiências de redução da DQO de amostras brutas e filtradas de 61% e 71%, respectivamente, o melhor coeficiente cinético aparente de primeira ordem (k1T): 0,52 ± 0,04 h-1, e uma biomassa predominantemente caracterizada por arqueas metanogênicas e bactérias fototróficas. O carvão vegetal apresentou resultados intermediários, no entanto não satisfatórios, na redução de DQO e ainda uma biomassa não compatível com a esperada para um tratamento anaeróbio biológico. Ou seja, pode-se inferir que neste tipo de suporte houve seleção de biomassa inadequada para se tratar esgoto sanitário. Por fim, o polietileno apresentou os resultados menos expressivos, porém, dada sua caracterização microbiológica constatou-se ser um suporte com potencial para o tratamento de esgoto sanitário quando nele for aplicado um tratamento prévio, objetivando melhores características físico-químicos, como rugosidade, por exemplo.
The main objective of this study was the evaluation of bed materials on the performance of an anaerobic sequencing batch biofilm reactor, with agitation, treating sewage wastewater of the Campus of University of São Paulo in São Carlos. The study of the global performance of this reactor configuration is extremely linked with the bed material which provides adhesive and growing conditions. In this work three different bed materials were investigated : polyurethane foam, vegetal carbon and recycled low-density polyethylene. The global evaluation was performed under analysis of three different and dependant local variables: the reactor performance, kinetic analyses and microbial exams. The polyurethane foam was considered the most suitable material. Using the polyurethane foam as a bed material were obtained the highest COD removal efficiencies, 61% and 71% corresponding to total and filtered samples, respectively. In Addition, the polyurethane foam showed the best modified first-order kinetic model (k1T) of 0,52 ± 0,04 h-1, and a biomass predominately characterized by microorganisms resembling to methanogenic archea and phototrophic bacteria . The vegetal carbon showed intermediate results, which were not satisfactory enough, in the COD removal. Also, the vegetal carbon showed an incompatible biomass in accordance with the expected anaerobic biomass. In others words, it can be inferred that, using this type of material, there was a selective biomass process in which an inappropriate biomass was selected. Finally, the recycled low-density polyethylene showed the less expressive results. However, because of its microbial characterization, it can be concluded that the polyethylene material has potential to be applied as a bed material in the sewage wastewater treatment. Nevertheless, a previous treatment physics-chemical must be applied in this kind of bed material to improve the physics-chemical properties such as porosity and surface area.
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20

Marins, Ângelo Máximo Fernandes. "Modelagem física e computacional do fluxo de aço em panela com agitação por gás inerte, com ênfase na separação de inclusões." Programa de Pós-Graduação em Engenharia de Materiais. Rede Temática em Engenharia de Materiais, Pró-Reitoria de Pesquisa e Pós-Graduação, Universidade Federal de Ouro Preto, 2011. http://www.repositorio.ufop.br/handle/123456789/2536.

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Devido ao aumento das exigências de qualidades dos aços, as empresas siderúrgicas têm melhorado continuamente seus processos e produtos. Os aços “clean steel”, são exemplos de produtos desenvolvidos para atender a um nível superior de qualidade. “Clean Steel” ou aço limpo pode significar menor número de impurezas ou residuais (Cu, Sn, por exemplos) e baixos níveis de inclusão. A homogeneização do banho, através da agitação do aço líquido, é um fator importante durante o processo siderúrgico, já que a homogeneização térmica e da composição química é um dos requisitos crítico do processo. A fim de minimizar os efeitos negativos das inclusões pode-se melhorar a taxa de remoção destas durante o refino secundário do aço e/ou modificar a morfologia e composição das inclusões. A remoção de inclusões está relacionada a fenômenos de fluxo. Assim, este trabalho é baseado em duas abordagens principais: 1 - Estudar o comportamento fluidodinâmico do aço líquido em uma panela de aciaria com injeção de gás inerte. Modelagem física e matemática (CFD) foram empregadas para avaliar a influência da taxa de injeção e da distribuição do gás, além da posição do plugue poroso sobre o campo de velocidade. O modelo numérico – CFD, foi validado pelas medições realizadas via “Particle Image Velocimetry” (PIV). 2 - A evolução do teor de inclusão de um aço acalmado ao alumínio foi avaliada através das análises de TOS e MEV. Como resultado, foi desenvolvido um modelo macroscópico para prever a remoção de inclusão com base nos mecanismos de Saffman & Turner e de Stokes. Ao final, evidenciou-se a influência de parâmetros operacionais, como vazão de gás injetado e tempo de tratamento, na flotação de inclusões não metálicas. A condição e vazão de 33,5 Nm3/h foi mais eficiente na remoção de inclusões, e as inclusões remanescentes eram menores nesta condição. Observou-se aumento da homogeneização do banho com a adição de mais um plugue poroso, com queda de 9% no tempo de mistura, quando se divide a mesma vazão de gás simetricamente entre os dois plugues. E o modelo matemático proposto mostrouse eficiente para descrever esse processo industrial. __________________________________________________________________________________________
ABSTRACT: Due to increasing steel quality requirements steelmaking companies have been continuously improving their processes and products. Clean steel is an example of a product developed for better quality. Clean steel could mean either lower impurity (Cu, Sn as examples) amount or lower inclusionary levels. Stirring of liquid steel is an important step during the steelmaking process since achieving chemical composition and temperature homogenization is a critical requirement. In order to minimize the negative effects of inclusions, one may is improve the rate of inclusions removal during the secondary refining of molten steel and modify the inclusions morphology and chemical composition. Inclusion removal is related to flow phenomena. Thus this work is based on two main approaches: 1 – Studying the fluid dynamic behavior of liquid steel in a ladle fitted with inert gas injection. Physical and mathematical modeling (CFD) have been employed to assess the influence of gas flow rate and gas distribution, nozzle position on the velocity field. CFD modeling was validated by Particle Image Velocimetry (PIV) measurements. 2 – The evolution of inclusion content of a given aluminum killed steel has been followed using techniques such as TOS, SEM. As a result a macroscopic model for inclusion removal based on Saffman & Turner and Stokes mechanisms have been developed. As a conclusion, the influence of operating parameters such as flow rate of gas injected and treatment time, in the flotation of non-metallic inclusions, was observed. The gas flow rate of 33.5 Nm3/h was more efficient in removal non-metallic inclusions, and the remaining inclusions were smaller in this condition. There was an increase of the bath homogenization with the addition of a more porous plug. The mixing time down in 9%, when it shares the same gas flow rate symmetrically between the two plugs. And the mathematical model was shown to be efficient to describe this industrially process.
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21

Delandar, Arash Hosseinzadeh. "Modeling defect structure evolution in spent nuclear fuel container materials." Doctoral thesis, KTH, Materialteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206175.

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Materials intended for disposal of spent nuclear fuel require a particular combination of physical and chemical properties. The driving forces and mechanisms underlying the material’s behavior must be scientifically understood in order to enable modeling at the relevant time- and length-scales. The processes that determine the mechanical behavior of copper canisters and iron inserts, as well as the evolution of their mechanical properties, are strongly dependent on the properties of various defects in the bulk copper and iron alloys. The first part of the present thesis deals with precipitation in the cast iron insert. A nodular cast iron insert will be used as the inner container of the spent nuclear fuel. Precipitation is investigated by computing effective interaction energies for point defect pairs (solute–solute and vacancy–solute) in bcc iron using first-principles calculations. The main considered impurities in the iron matrix include 3sp (Si, P, S) and 3d (Cr, Mn, Ni, Cu) solute elements. By computing interaction energies possibility of formation of different second phase particles such as late blooming phases (LBPs) in the cast iron insert is evaluated. The second part is devoted to the fundamentals of dislocations and their role in plastic deformation of metals. Deformation of single-crystal copper under high strain rates is simulated by employing dislocation dynamics (DD) method to examine the effect of strain rate on mechanical properties as well as dislocation microstructure development. Creep deformation of copper canister at low temperatures is studied. The copper canister will be used in the long-term storage of spent nuclear fuel as the outer shell of the waste package to provide corrosion protection. A glide rate is derived based on the assumption that at low temperatures it is controlled by the climb rate of jogs on the dislocations. Using DD simulation creep deformation of copper at low temperatures is modeled by taking glide but not climb into account. Moreover, effective stresses acting on dislocations are computed using the data extracted from DD simulations.

QC 20170428

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22

Nugay, Isik Isil. "POLYURETHANES in RIGID and FLEXIBLE ELECTRONICSNOVEL HYBRID PROCESSING TECHNIQUES and REAL-TIME MONITORING OF MATERIAL PROPERTIES." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1406633847.

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23

Podstata, Jan. "Volba optimálního nástroje pro vybranou technologii obrábění." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-432700.

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This thesis compares the properties of four types of replaceable cutting tool inserts from different suppliers during milling. The comparative factors are cutting force, material loss of the insert and the roughness of the resulting surface. The thesis is divided into two parts - a comprehensive overview of the current state of knowledge and an experiment. The first part analyzes the load, the possibility of its measurement, surface treatment of tools, milling cutters and replaceable inserts. The experiment took the form of measuring the load during face milling, measuring the surface roughness of the machined material and measuring the material loss of the inserts on an optical strain gauge. The replaceable cutting tool inserts were compared based on the performed measurements.
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24

Tragangoon, Arruck. "Etude d'assemblages multi-matériaux par boulonnage, par fixation avec insert et par collage d'une structure composite." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEM048.

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Pour alléger les véhicules, des structures multi-matériaux utilisant des matériaux composites sont envisagées par les industriels automobiles. Les liaisons sont les points faibles de ces structures. Dans ce travail de thèse, le boulonnage, la fixation par insert et le collage utilisés dans l’assise d’un siège automobile en métal/composite ont été étudiés. Les pièces envisagées de l’assise ont été réalisées en composite tissé (verre/ PA6) et en composite injecté (verre/PA66). Y compris pour les films adhésifs, les lois de comportement ont été établies à partir d’essais expérimentaux. Pour les pièces munies d’un trou et pour la liaison boulonnée, le volume critique déterminant la rupture du composite tissé a été utilisé dans les calculs numériques. Dans le cas du collage, la distance critique déterminant la rupture de l’adhésif a aussi été considérée. Des éprouvettes de simple recouvrement et des triangles collés soumis à la torsion ont été testés et simulés. Pour la rupture d’une pièce en composite injecté à fibres courtes, la résistance mécanique du matériau a été évaluée en fonction de l’orientation locale des fibres. Une bielle en composite injecté a été testée et calculée. Les lois de comportement et les méthodes de prédiction de rupture établies ont été utilisées dans le calcul numérique du siège soumis à l’essai de choc
To reduce the weight of vehicles, the multi-material structures with composite materials have been used in the automotive industries. However, the joints are considered as the weakest parts of the structure. In this work, the joining methods used for metal/ composite automotive seat, including a mechanical joint, a threaded insert and an adhesive joint, have been studied. The components of the seat under consideration were made of woven composite (glass/PA6) and short fiber composite (glass/PA66). The mechanical behaviors of the studied materials, including adhesives, have been modeled based on the experimental results. For parts containing an open-hole and for mechanical joints, the characteristic volume has been used to determine the failure of woven composite. In the case of adhesive joints, the characteristic length has been used to determine the failure. Single lap shear tests and the torsion tests on a bonded structure were conducted and simulated. For the failure of short fiber composite structure, the material strength has been evaluated as a function of local fiber orientation. The tensile tests on the short fiber composite connecting rod were conducted and simulated. Finally, the proposed constitutive laws and failure prediction methods were applied for the simulation of the automotive seat under crash test condition
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Bautista, Salas Julio César. "Diseño de un equipo de volumen constante para caracterizar procesos físicos de la inyección de combustibles líquidos en un medio inerte." Bachelor's thesis, Pontificia Universidad Católica del Perú, 2016. http://tesis.pucp.edu.pe/repositorio/handle/123456789/8647.

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La presente tesis tuvo como objetivo diseñar un equipo de volumen constante para caracterizar los parámetros físicos en la inyección de combustibles líquidos en medios inertes (sin combustión). Para lograr este objetivo, primero se realizó una revisión de un consolidado de artículos relacionados con el trabajo de tesis desarrollado. Además, se relacionaron los conceptos de termo-fluidos y resistencia de los materiales para construcción del equipo de volumen constante. Mediante la norma VDI 2221 se evaluaron distintos diseños preliminares con el objetivo de encontrar el diseño óptimo de este equipo. Luego, se definieron los parámetros para el diseño del equipo: presión interna de 10 MPa y volumen interno de 4L. Con estos parámetros se procedió a dimensionar el equipo de volumen constante usando el código ASME para recipientes a presión. Debido a que el código ASME no está enfocado directamente al diseño de este tipo de equipos, se validó dicho diseño mediante un análisis por el método de elementos finitos, con el cual se verificó que el equipo cumplía con las exigencias mecánicas. Luego, se procedió a realizar los planos de ingeniería y de detalle del equipo. Finalmente, se realizó un metrado de los materiales y posterior proceso de fabricación con la finalidad de realizar un análisis de costos de fabricación del equipo, en el cual se obtuvo un valor de S/. 59 437.70 nuevos soles.
Tesis
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26

Ramirez-Quintero, Deyber Alexander 1985. "Influência da granulometria do material inerte e da composição de misturas binárias contendo areia e partículas de bambu (in natura e carvão produto do processo pirolítico) sobre a fluidodinâmica de leitos fluidizados." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265823.

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Orientador: Araí Augusta Bernárdez Pécora
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A aplicação de biomassas em processos de geração de energia como a combustão, pirólise e gaseificação, operando com a tecnologia de leito fluidizado, tem merecido atenção crescente nas últimas décadas. Esses sistemas necessitam da adição de partículas de material inerte que ajudam a promover uma fluidização estável, permitindo a melhoria da eficiência de tais processos. Dentre as biomassas com potencial para geração de energia sustentável está o bambu, material que apresenta propriedades semelhantes às de outras biomassas utilizadas em processos de geração de energia, com a vantagem de apresentar rápido crescimento, fácil propagação, regeneração vigorosa, maturidade rápida. O objetivo deste projeto foi estudar o comportamento fluidodinâmico de misturas de partículas de areia e bambu (in natura e na forma de carvão proveniente de processo de pirólise) visando à obtenção de parâmetros inerentes à fluidização dessas misturas, bem como analisar o efeito da degradação térmica da partícula de bambu sobre a fluidização do leito. A análise foi realizada a partir do levantamento experimental da curva fluidodinâmica em sistema de leito fluidizado operando a frio, com diferentes composições das misturas bambu-areia e carvão-areia. Adicionalmente foi verificada a influência do tamanho das partículas de areia e da altura estática do leito sobre a fluidodinâmica do leito. Os resultados mostraram que a melhor qualidade da fluidização do leito contendo partículas de bambu in natura foi obtida usando a areia identificada como areia 3 (diâmetro médio de 460 µm), relação entre a altura estática do leito e o diâmetro do leito igual à unidade (H/D = 1) e máximo teor de biomassa no leito igual a 5% (em massa). No entanto, esse tamanho areia não forneceu boas condições de fluidização para a mistura carvão-areia. A utilização da Umf do material inerte para o projeto de reatores de pirólise, utilizando partículas de bambu como combustível, não é recomendável, uma vez que a presença de apenas 5 % (em massa) de bambu in natura aumenta o valor da Umf em 20 %, enquanto que esse aumento é de 10 % no leito contendo carvão de bambu. Espera-se que os resultados obtidos neste estudo forneçam dados úteis para o projeto de reatores que utilizam a tecnologia de leito fluidizado. Pretende-se também contribuir para o entendimento da fluidodinâmica de sistemas que utilizam misturas de biomassas e areia para geração de energia
Abstract: The use of biomass in power generation processes such as combustion, pyrolysis and gasification, operating with the fluidized bed technology, has received increasing attention in recent decades. These systems require the addition of inert particles to promote a stable fluidization, allowing the improvement of process efficiency. Among the biomasses with potential for sustainable power generation is bamboo, which presents similar properties to other biomasses used in energy generation processes, with the advantage of rapid growth, easy propagation, vigorous regeneration and quick maturity. In addition, its properties allow the recovery of environmentally degraded areas. The objective of this research was to study the hydrodynamics behavior of fluidized beds composed by mixtures of sand and bamboo particles (in natura and in the form of coal from pyrolysis process). Parameters inherent to fluidization of these mixtures, as well as the effect of thermal degradation on the fluidization process of bamboo particles are analysed. The analysis was performed from hydrodynamics curves obtained in an experimental system operating at room temperature, with different compositions of bamboo in nature and bio-char in the bed. Additionally, the influences of sand particle size and static bed height on the fluidized bed hydrodynamics were verified. Results showed that the best quality of fluidization of the studied mixtures was achieved using sand particles 460 ?m diameter (sand 3), static bed height and column diameter ratio equal to unity (H/D = 1) and maximum weight fraction of bamboo in the bed equal to 5%. However, this size of sand particles did not provide a good quality of fluidization for coal-sand mixture. The Umf of the inert material is not recommended to be used in the design of pyrolysis reactors as the addition of 5 wt% of bamboo in natura in the bed causes an increment of 20 % on Umf while this increment is 10 % for the bed containing bamboo char. Results obtained from this study could provide useful data for the design of fluidized bed reactors that operate with bamboo particles. It is also intended to contribute on understanding the hydrodynamics behavior of fluidized beds using mixtures of biomass and sand for power generation
Mestrado
Termica e Fluidos
Mestre em Engenharia Mecânica
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27

Tejkl, Jakub. "Trvanlivost destiček ADMX při frézování materiálů skupiny S." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231383.

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This diploma thesis studies the machining of group S materials. In the theoretical part of this thesis these materials were divided into groups and subsequently analyzed. These materials were also analyzed in terms of their impaired machinability. In the practical part of this thesis experimental tests were conducted to determine tool life, tool wear and in the case of testing titanium alloy surface roughness too.
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28

Vernon, Jonathan P. "Morphology-preserving chemical conversion of bioorganic and inorganic templates." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47521.

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The generation of nanostructured assemblies with complex (three-dimensional, 3D) self-assembled morphologies and with complex (multicomponent) tailorable inorganic compositions is of considerable technological and scientific interest. This research demonstrates self-assembled 3D organic templates of biogenic origin can be converted into replicas comprised of numerous other functional nanocrystalline inorganic materials. Nature provides a spectacular variety of biologically-assembled 3D organic structures with intricate, hierarchical (macro-to-micro-to-nanoscale) morphologies. Morphology-preserving chemical conversion of such readily available, structurally complex templates will provide a framework for chemical conversion of synthetic organic templates and, potentially, production of organic/inorganic composites. Four research thrusts are detailed in this dissertation. First, chemical conversion of a nanostructured bioorganic template into a multicomponent oxide compound (tetragonal BaTiO₃ via layer-by-layer surface sol-gel coating and subsequent morphology-preserving microwave hydrothermal processing was demonstrated. Second, photoluminescence was imparted to bioorganic template structures through morphology-preserving chemical conversion to exhibit both the dramatic change in properties such processing can provide, and the potential utility of chemically transformed templates in anti-counterfeiting / authentication applications. Third, the reaction mechanism(s) for morphology-preserving microwave hydrothermal conversion of TiO₂ to BaTiO₃, were studied with the aid of Au inert markers on single crystal rutile TiO₂. Finally, constructive coating techniques (SSG) and moderate temperature (< 500C) heat treatments were utilized to modify and replicate structural color and were coupled with deconstructive focused ion beam microsurgery to prepare samples for microscale structure/property interrogation. Specifically, the effects of coating thickness and coating composition on reflection spectra of structurally colored templates were examined. Also, the effects of the replacement of natural material with higher index of refraction inorganic materials on optical properties were studied. The three processing research thrusts constituting chapters 1, 2 and 4 take advantage of moderate temperature processing to ensure nanocrystalline materials, either for shape preservation or to prevent scattering in optical applications. The research thrust presented in chapter 3 examines hydrothermal conversion of TiO₂ to BaTiO₃, not only to identify the reaction mechanism(s) involved in hydrothermal conversion under morphology-preserving conditions, but also to introduce inert marker experiments to the field of microwave hydrothermal processing.
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29

Han, Jixiong. "Processing Microstructure Evolution and Properties of Nanoscale Aluminum Alloys." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1121701078.

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30

Roubalová, Jana. "Aplikace svařování elektronovým svazkem pro rekonstrukci vzorků pro mechanické zkoušky z malých objemů materiálu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234454.

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This thesis is focused on application samples with the inner insert used for Charpy impact test. This insert is welded to additional material by electron beam with pre-selected welded parameters. These parameters were chosen from data of performed experiments on homogenous welds. Resulting heterogenous weld was performed of evaluation of the microstructure, chemical composition and microhardness. Experimental materials were used austenitic steel 17 240 and ferritic steel 17 153 used on high-temperature applications.
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31

Pal, Terek. "Unapređenje kvaliteta alata za livenje pod pritiskom primenom tehnologija inženjerstva površina." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2016. http://www.cris.uns.ac.rs/record.jsf?recordId=101472&source=NDLTD&language=en.

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Proučavane su koroziona postojanost i tendencija lepljenja različitihmaterijala u kontaktu sa tečnom Al–Si–Cu legurom. Ispitivanjem suobuhvaćeni čelik za rad na toplo, plazma nitrirani čelik i dupleksslojevi sa CrN, TiAlN, TiAlSiN i CrAlN prevlakama, različitog nivoapovršinske hrapavosti. Za ispitivanja pomenutih fenomenaprimenjena je metoda izvlačenja, koja je unapređena kako bi se povećalenjena tačnost i verodostojnost simulacije procesa livenja. Korozioniefekti su pojačani tako što su uzorci osim kratkog kontakta sa odlivkomzadržavani i u dužim periodima u kontaktu sa tečnom legurom (5 i 20min). Uprkos opštim stavovima, za ispitivane materijale jeustanovljeno da su sile izvlačenja uzoraka iz Al–Si–Cu odlivakanezavisne od njihovog hemijskog sastava. Uticaj hrapavosti je izraženkod uzoraka sa prevlakama kod kojih pri smanjenju hrapavosti dolazi dopovećanja sile izvlačenja. Sve ispitane prevlake su sklone mehaničkomlepljenju Al–Si–Cu legure za svoje površine, ali sa aspekta korozije utečnom metalu značajno prevazilaze performanse čelika i plazmanitriranog sloja. Duži kontakt livene legure sa površinama prevlakauzrokovao je niže vrednosti sila izvlačenja, što je posledicaoksidacije površina prevlaka. Ustanovljeno je da su ispitivaneprevlake inertne ka tečnoj leguri aluminijuma. Međutim, dolazi dooksidacije i korozije materijala podloge kroz greške rasta koje suprisutne u prevlakama. Stečena znanja o identifikovanimmehanizmima habanja i propadanja zaštitnih slojeva prevlakaposlužiće daljem razvoju dupleks slojeva namenjenih za zaštitu alataza livenje pod pritiskom.
Corrosion resistance and soldering tendency of different materials in moltenAl–Si–Cu alloy were studied. Hot-working tool steel, plasma nitrided steel andduplex layers with CrN, TiAlN, TiAlSiN and CrAlN top coatings, which wereproduced to various degree of surface roughness, were covered by the study.An ejection test was employed for investigation of the concerned phenomena.The ejection test was improved in order to increase its accuracy and thereliability of process simulation. Samples were examined in both short andextended periods of contact (5 and 20 min) with liquid casting. Castingsolidification was extended in order to intensify the corrosion effects. Contraryto common findings, it was found that the ejection force of the investigatedmaterials does not depend on their chemical composition. For the coatedsamples, a pronounced dependence of the ejection force on the surfaceroughness was found. The ejection force increases with decrease in surfaceroughness. All investigated coatings are prone to mechanical soldering by Al–Si–Cu alloy. Still, their corrosion resistance substantially exceeds the corrosionresistance of steel and plasma nitrided layer. Longer exposure of coatedsamples to cast alloy induced lower ejection forces, which is a consequenceof coatings oxidation. It was found that the investigated coatings are inert toliquid aluminium. However, the underlying material undergoes oxidation andcorrosion through coating growth defects. The findings concerning the wearmechanisms of protective layers support further development of duplex layersintended for die casting tools protection.
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32

Sadoway, Donald R. "Inert Anodes for the Hall-Heroult Cell: the Ultimate Materials Challenge." 2001. http://hdl.handle.net/1721.1/1683.

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33

"Analysis of Nuclear Fuel Cycle Materials by X-ray Absorption Spectroscopy." Thesis, 2016. http://hdl.handle.net/10388/ETD-2016-01-2382.

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Nuclear energy can be used to reliably generate large quantities of electricity while providing minimal lifetime CO2 emissions. Given the extreme importance of safety in the nuclear industry, it is necessary to have a fundamental understanding of the materials used throughout the nuclear fuel cycle. It is of particular to importance to develop an understanding of these materials at an atomic level. In this thesis, X-ray absorption spectroscopy (XAS), along with several other X-ray based techniques, has been used to study materials that are produced or proposed for use in the nuclear fuel cycle. Uranium mining and milling operations generate large quantities of waste, known as mine and mill tailings. At their McClean Facility in Northern Saskatchewan, AREVA Resources Canada disposes of the tailings waste using the JEB Tailings Management Facility (TMF). AREVA monitors the mineralization of elements of concern (i.e., Ni, As, Fe, Mo, Ra, and U) within the TMF as part of its on-going commitment towards managing the facility’s environmental impact. Molybdenum (Mo) is predicted to mineralize as insoluble powellite (CaMoO4) within the TMF. However, no experimental evidence confirmed the presence of powellite in the TMF. In Chapter 2, the presence of powellite, and other Mo-bearing minerals, was determined using powder X-ray diffraction (XRD), X-ray fluorescence imaging, and Mo K-edge XAS. The results of this study confirmed that powellite was present in the TMF and showed that Mo K-edge XAS was the only effective way to detect the Mo minerals within the TMF. New materials for use as nuclear fuels were also investigated in this thesis. Spent nuclear fuel must be securely stored for long periods of time due to the presence transuranic elements (TRU; i.e., Pu, Am, Np, Cm), and the use of inert matrix fuels (IMF), which consist of actinides embedded in a neutron transparent (inert) material, have been proposed for to “burn-up” or transmute these TRU species. Stabilized ZrO2 materials have been proposed for use in IMF applications, and in Chapter 3 the thermal stability of a series of NdxYyZr1-x-yO2-\delta materials made by a ceramic synthetic route have been studied using powder XRD, scanning electron microscopy (SEM), and X-ray absorption spectroscopy. (Nd was used as a surrogate for Am.) The results of this study showed that the fluorite structure of the NdxYyZr1-x-yO2- \delta materials was stabilized when y >= 0.05, and that the local environment around Zr was independent of composition or annealing temperature. The effect of synthetic method on the thermal stability of the NdxYyZr1-x-yO2-\delta materials was also determined, and this is the subject of Chapter 4. In this study a series of NdxY0.25-xZr0.75O1.88 materials were synthesized using a low-temperature co precipitation synthesis, and these then annealed at 1400 °C and 1500 °C. The as-synthesized and annealed materials were characterized by powder XRD, SEM, and XAS. This study confirmed that the thermal stability of the materials was dependent on synthetic method, and that materials made using a solid-state method were superior to those produced by a solution-based approach. Y-stabilized zirconia has a low thermal conductivity, which is not ideal for a nuclear fuel. The thermal conductivity could be increased if a lighter cation, such as Sc, was used to stabilize the fluorite structure. In Chapter 5, the thermal stability of a series of NdxScyZr1-x-yO2-\delta materials was investigated. The as-synthesized and annealed materials were studied by powder XRD, SEM, and XAS. These results showed that the fluorite structure was only stable in the annealed materials when x+y >= 0.15 and y >= 0.10. The results of this study provided insight into the possible use of scandia-stabilized zirconia for use as an inert matrix fuel. This studies presented in this thesis have used X-ray absorption spectroscopy and a number of other techniques to characterize materials important to the nuclear fuel cycle. The studies presented here were only possible because of the unique information that can be obtained using XAS. This thesis serves to highlight the importance of XAS as a technique and how it can be applied to solve problems related to the material science of the nuclear fuel cycle.
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34

Yount, Hannah J. "Hardness and fracture toughness of heat treated advanced ceramic materials for use as fuel coating and inert matrix materials in advanced reactors." 2006. http://catalog.hathitrust.org/api/volumes/oclc/71252585.html.

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Thesis (M.S.)--University of Wisconsin--Madison, 2006.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 91-98).
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35

Hung, Wei-Shen, and 洪維伸. "A Study in Optimal Process of An Insert Twin-materials Loading Roller." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/68262991261399107398.

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碩士
國立高雄應用科技大學
模具工程系
97
In order to achieve the requirements of localized instruments and low cost of production line of the thin-film transistor liquid crystal display (TFT-LCD), The low cost UHMWPE disk is covered by the high strength PEEK loop, this research uses the insert-twin materials injection designing on the loading roller of glass substrate, and the twin-materials loading roller is further developed. While the outer size and roundness of loading roller is not in tolerance, the irregular vibrations formed between the glass substrate and the loading roller, the surface of the glass substrate was broken and this lead to the bad products. Thus, the mainly purpose of this research is to minimize the outer size and roundness of loading roller. Moreover, to simulate the forming processing of insert twin-materials injection by the computer-aided engineering (CAE) software, and investigate the effects upon the shrinkage and roundness of twin-materials loading roller on the processing procedures such as mold temperature, melt temperature, injection flow rate, packing pressure, packing time and cooling time. The testing standard of roundness of the twin-materials loading roller is measured by the least squares circle (LSC), the maximum inscribed circle (MIC), the minimum circumscribed circle (MCC), and the minimum zone circle (MZC) according to ISO 1101 /DIN 7184, and further measures the roundness by the Moldflow software. Finally, the double quality optimum analysis is performed by Grey Relational Grade combining the Taguchi method. The optimum processing procedures of the minimized roundness and the diameter shrinkage are obtained. The results show that the material cost can be reduced by the structural designing of twin-materials loading roller and the reduction approaches 49%. Compares with the results of roundness, the largest measuring error is LSC and the lowest measuring error is MZC. From the single quality optimum results, the mainly factor affecting the roundness is the “injection flow rate”, and the mainly factor affecting the diameter shrinkage is the “packing pressure”. From the double quality optimum results, the double quality characterizes are affected by the processing procedures such as the “injection flow rate”, “packing pressure” and “packing time”. Concludes the effecting levels of the processing procedures, the inert stress surrounding the gate and the pressure disparity between the gates and filling ending can be reduced by process settings such as lowly injection flow rate, high packing pressure and short packing time, the deforming of roller diameter can be minimized effectively. The best procedure of combinations are obtained, including of low mold temperature (150℃), high melt temperature (370℃), low injection flow rate (6 cm3/s), high packing pressure (51.40 MPa), short packing time (1 sec.) and long cooling time (12 sec.). Summarizes the mentioned above, the novel twin-materials loading roller with high surface strength and low cost has presented successfully in this research. These rollers can be applied on the baggage, trolley of aviation and nursing in the future. The measuring methods can be also applies on the analysis upon the roundness and diameter of the exact plastic products such as the plastic syringe head, plastic bearing in the future. This indicates that the widely quality measuring methods of the circular plastic products in mold flow software are developed.
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36

Lin, Jun-Da, and 林君達. "Study on Various Materials of Mold Insert for the Processing of Microfluidic Chip." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/18148139076491314650.

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碩士
龍華科技大學
機械系碩士班
94
This study uses the microfluidic chip as example to discuss the materials of mold insert on hot embossing molding. For the mold insert, firstly, this study uses the SU-8 photoresist to coat on the silicon wafer, and then uses the UV light to expose the pattern on the surface of SU-8 photoresist, and then it uses the thermal evaporation to coat the seed layer on SU-8 structure. This study combines the micro electroforming technology to fabricate the mold insert (Ni, Cu, Ni-Co), and the silicon mold insert by exposes and ICP etches. Finally, this study uses the micro hot embossing molding to replicate the micro structure from the metal mold insert. This study uses the Taguchi method (L9 table) to discuss the different processing parameters (processing temperature, embossing pressure, embossing time, de-molding temperature) for the properties of COP film of microfluidic chip. This study uses AFM to measure the surface roughness of microfluidic chip. The results use to discuss the properties of surface roughness for different processing parameters; the hardness of different metal mold inserts and the life of mold insert life. The results show that the most important parameter is the processing temperature for replication properties. The de-molding temperature is most important parameter for surface roughness. The Ni-Co mold insert is the most suitable material for micro hot embossing molding.
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Hsu, Wei-mau, and 徐維懋. "Materials Characteristics of Spinel Nickel Ferrite Oxygen Carrier and It’s Selection of Inert Supports for Chemical Looping Combustion Process." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/01088156383690048443.

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碩士
國立臺灣科技大學
機械工程系
100
Chemical looping combustion (CLC) process is a promising technology of CO2 capture and sequestration (CCS) with high energy efficiency and low emission of greenhouse gases. For the practical use, the performance of oxygen carriers is a key issue for the application on CLC process. Unfortunately, the formation of inactive compounds by the interaction between the ordinary metal oxygen carriers and inner supported were evidently encountered in a CLC process, which subsequently reduced the performance of CLC process. In our preliminary results, after 5 successive cycles, NiFe2O4 powder with a single phase of spinel structure represented a higher redox cycling behavior and stability as compared to the standard of NiO and Fe2O3. To identify the initial reduction mechanism of NiFe2O4, we obtained the activation energy (Ea) of the reduction behavior using the reduction rate equation and Arrhenius equation. However, at long redox cycles (10 cycles), the performance of NiFe2O4 oxygen carriers was dramatically reduced due to the agglomeration of oxygen carriers. Thus, the addition of inner materials as the supports to oxygen carriers is a necessary process to prepare a superior oxygen carrier system in the operation of long redox cycles in CLC process. This study is to investigate the effects various inner supports (Al2O3, ZrO2 and YSZ) of in NiFe2O4 oxygen carrier system and the performance of CLC process by TGA system. Mingled various inner supports shift the reduction kinetics of oxygen carriers, NiFe2O4/Al2O3 system decayed the reduction kinetics but both NiFe2O4/ZrO2 and NiFe2O4/YSZ system promoted the reduction kinetics. To identify the initial reduction mechanism and activation energy, NiFe2O4/Al2O3 system’s activation energy is 83.4 kJ/mol reduction mechanism controlled by solid-state diffusion. For the systems of NiFe2O4/ZrO2 and NiFe2O4/YSZ, both reduction mechanisms are mainly dominated by gas diffusion with the activation energy values of 9.0 kJ/mol and 10.1 kJ/mol, respectively. Our results also demonstrated the higher redox cycling behavior of using the proposed preparation of NiFe2O4 as an oxygen carrier with Al2O3 support in a reversible chemical looping process (CLP).
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Κυριαζοπούλου, Ελένη. "Καταλληλότητα αδρανών υλικών για έρμα σιδηροδρομικών γραμμών: έρευνα σε δείγμα Νο2 βασικών και υπερβασικών πετρωμάτων." Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4738.

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Στη διπλωματική αυτή εργασία γίνεται μελέτη της τεχνικογεωλογικής συμπεριφοράς βραχωδών σχηματισμών για την καταλληλότητά τους και την χρήση τους ως αδρανή υλικά σε έρμα σιδηροδρομικών γραμμών ταχείας κυκλοφορίας.
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Πανούτσου, Νικολίτσα. "Καταλληλότητα αδρανών υλικών για έρμα σιδηροδρομικών γραμμών: έρευνα σε δείγμα Νο1 βασικών και υπερβασικών πετρωμάτων." Thesis, 2011. http://nemertes.lis.upatras.gr/jspui/handle/10889/4739.

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Liu, Yi-Chun, and 劉怡君. "A Study on the Foot Pressure Distribution of Court Shoes Heel Heights and Insert Materials." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/65776686930832810715.

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碩士
國立成功大學
工業設計學系
85
Abstract Office women usually wear Court Shoes to show their beautiful appearance but this kind of shoes are easy to cause discomfort and high pressure on feet. Besides, discomfortable foot wear will disturb wearers'' emotion and reduce their working efficiency. Therefore, the purpose of this study was to improve the discomfort due to the heel height of Court Shoes. In this experiment ten healthy female subjects which were no foot diseases and aged from 20-35 volunteers to participate. In this study, the Foot-scan was used to determine the efficiency of pressure redistribution with fourdifferent shoe inserts as compared with control variables(no inserts). Data were analyzed by using the "One-way ANOVA" and "post hoc LSD test". After the statistic discussion, significant statistic differences in peak pressure between PU material inserts and control condition in 2nd-3rd metatarsals were noted. Finally, we can conclude that the middle density PU material insert can be beneficial in relieving pressure in 2nd-3rd metatarsals.Keywords: Court Shoe , High Pressure, Shoe Inserts, Pressure Distribution
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Kuen-Ming, Yang, and 楊坤明. "A Study on the Effects of the Insert Material and Height of Arch Support for Different Foot Patterns." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/63485359976473273112.

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碩士
大同工學院
工業設計研究所
86
The human foot may be catagoried into the high-arch foot, normal-arch foot, and low-arch foot according to the arch height. These three foot patterns have significant differences in plantar pressure distribution during walking. Because a high plantar pressure may induce foot diseases and an insert may reduce the pressure. Therefore this study aims to find out the relationship among foot patterns, the hardness of the insert material, and the height of the arch support by changing the hardness of the EVA inIn this study, the EMED-SF system and the Micro-EMED system were used to measure the plantar pressure. The design of the experiment consisted of twenty-two subjects (six for high-arch foot, eight for normal-arch foot and eight for low-arch foot), using three different degrees of hardness of EVA insert materials (35, 40, 45) with four different levels of height of the arch support (0 mm, 15 mm, 19.5 mm, 30 mm) to design twelve different inserts for experiment action and the peak plantar pressure during walkiThe results have shown that the effects on plantar pressure were different for the height of the arch support in different foot patterns during walking. People with the low-arch foot need an insert which has a high arch support (30 mm). People with normal-arch foot need an insert which has a medium arch support (15 mm, 19.5 mm). But the result of the experiment showed that the change in the height of the arch support exerted no significant influence on the high-arch group. The results in regard to hardness
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Delgado, Bruno Guimarães. "Geomecânica de um agregado siderúrgico inerte como material alternativo para lastro de vias férreas do tipo heavy haul." Tese, 2019. https://hdl.handle.net/10216/125559.

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Delgado, Bruno Guimarães. "Geomecânica de um agregado siderúrgico inerte como material alternativo para lastro de vias férreas do tipo heavy haul." Doctoral thesis, 2019. https://hdl.handle.net/10216/125559.

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Zenobia, Samuel J. "Simulation of inert gas effects to fast reactor SCWR fuel cladding and ion implantation of first wall armor materials for fusion reactors." 2007. http://catalog.hathitrust.org/api/volumes/oclc/150572069.html.

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Coelho, João Luís Barroso Brandão. "Effect of exposure conditions on UV-curable coatings films performance." Doctoral thesis, 2018. http://hdl.handle.net/1822/59053.

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Tese de Doutoramento em Ciências e Engenharia de Polímeros e Compósitos
The ultraviolet-radiation (UV) curing represents a growing technology where the conversion of a radiation sensitive polymeric system from a liquid to a solid (upon curing) is achieved when the system is exposed to UV radiation. Instantaneous cure, even at room temperature, low energy consumption, films with great mechanical and chemical resistance, together with low volatile organic compounds (VOC) emissions, are examples of the type of questions that raised the interest on UV curing technology in the last years, trying to extend its application to demanding new markets, such as the automotive one. UV curing technology should be thought as a complex system, based on three structural elements, which are integrally related: the part to be coated, the formulation of the UVcurable system, and the exposure conditions (which are defined by the UV reactor performance, the part geometry and the cure atmosphere). This work was devoted to understanding the correlation between the exposure conditions and the formulation of UV-curable coatings, on coating films performance. For this sake, a methodology was proposed to evaluate the performance of UV reactors based on the response surface methodology (RSM), being the same applied and validated for an industrial UV reactor. Based on the regression models developed, the UV reactor was configured to cure two coatings, one transparent and one black, with a high gloss finish, with two conditions of energy density (500mJcm-2 and 2000mJcm-2) and in two cure atmospheres (inert and non-inert). The effect of the exposure conditions was evaluated through the gel content of the films and through coating films properties like colour, adhesion, scratch resistance, hardness and reduced modulus. The coated samples were further aged and characterized. The performance of coatings improved when UV-curable coatings were cured with high energy density and with inert atmosphere, showing higher hardness, reduced modulus and abrasion resistance. However, under these curing conditions the coating films also showed a greater tendency to yellowing and darken. Curing in inert atmosphere and with lower energy density allowed to minimize these secondary effects, and to optimize the overall performance of the coating films.
A cura por radiação ultravioleta (UV) representa uma tecnologia em crescimento, onde a conversão de um sistema polimérico fotossensível do estado líquido ao sólido, é alcançada quando este é exposto à radiação ultravioleta. A cura instantânea, mesmo à temperatura ambiente, o baixo consumo de energia, a grande resistência mecânica e química dos filmes, juntamente com as baixas emissões de compostos orgânicos voláteis (VOC), são exemplos do tipo de questões que fomentaram o interesse na tecnologia UV nos últimos anos, para a sua aplicação em novos mercados, como o automóvel. A tecnologia de cura por UV deve ser pensada como um sistema complexo, baseado em três pilares estruturais, que estão integralmente relacionados: a peça a revestir, a formulação da tinta e as condições de exposição (que são definidas pelo desempenho do reator UV, a geometria da peça e a atmosfera de cura). Este trabalho focou-se no estudo da correlação entre as condições de exposição, a formulação das tintas curáveis por UV e o desempenho do revestimento. Para isso foi proposta uma metodologia para avaliar o desempenho dos reatores UV baseada na metodologia de superfície de resposta (RSM), tendo a mesma sido aplicada e validada num reator UV industrial. Com base nos modelos de regressão desenvolvidos, o reator UV foi configurado para curar duas tintas, uma transparente e outra preta, com acabamento alto brilho, sob duas condições de densidade energia (500mJcm-2 e 2000mJcm-2) e sob duas atmosferas de cura (inerte e não inerte). O efeito das condições de exposição foi avaliado através do teor de gel dos revestimentos e o desempenho destes através de propriedades como a cor, a adesão, a resistência ao risco, a dureza e o módulo reduzido. As amostras pintadas foram ainda envelhecidas e caracterizadas. O desempenho dos revestimentos melhorou quando as tintas UV foram curadas sob elevada densidade de energia e sob atmosfera inerte, apresentando maior dureza, módulo reduzido e resistência à abrasão. No entanto, sob estas condições de cura os revestimentos apresentaram maior tendência a amarelecer e a escurecer. Curar sob atmosfera inerte e com menor densidade de energia permitiu minimizar estes efeitos secundários e otimizar globalmente o desempenho do revestimento.
Fundação para a Ciência e Tecnologia (FCT) - Through the scholarship with reference SFRH/BDE/52128/2013
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Hsieh, Chi-Feng, and 謝齊峰. "Determination of the Working Potential Windows of Porous Carbon Materials for Capacitive Deionization and Invert Capacitive Deionization." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ndf9ys.

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Hsu, Hong-Kai, and 徐宏愷. "The improvement of the hydroxyapatite coatings by alternate soaking method on the hydrophilized surface of the inert materials with the acetic acid plasma treatment." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/33tmqx.

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碩士
大同大學
材料工程學系(所)
107
There are many different materials used in bone or dentistry, such as metals, ceramics and polymers. However, due to the inertness of the surface of the material, most of it is hydrophobic and stable. If it is used for biomedical materials, it is not easy to adapt to the surface deposited hydrogen apatite (HA). If there is a polar group on the surface, it is easy to bond with a biocompatible polymer or ceramic. In order to effectively adhere HA to the hydrophobic polymer surface, the surface properties of the polymer material are changed by cold plasma technology, and acetic acid (Acetic acid) contains hydrophilicity such as -OH, -C=O, -COOH group. surface. The interaction method is used to deposit hydroxyapatite (HA) impregnated with ion solution (Ca2+, CaNO3) and (PO42+, (NH4)2HPO4) to make HA adhere to the surface. In this study, glass, aluminum foil, stainless steel and TPU (thermoplastic polyurethane) non-woven fabrics were used. The plasma treatment used internal electrode vacuum plasma equipment, and the acetic acid precursor vapor was introduced to change the plasma treatment time. Using the water contact angle (WCA), it was found that the surface of the test piece exhibited a hydrophilic effect, and ATR-FTIR confirmed that the surface had a hydrophilic functional group (-OH, -CH, -C=O). The HA is then deposited on the surface by interactive soaking. The deposition weight was measured by QCM and electronic balance, and the deposition effect of TPU was found to be the best. SEM found that the amount of HA deposited on the surface after plasma modification was more than that of the untreated type. The crystal structure confirmed by XRD confirmed that the finished product was HA, and finally proved to be biocompatible through 3T3 fibroblasts and MG63 osteoblast culture. Osteophysiology. It is expected that the HA of surface formation is expected to contribute to future biomedical applications.
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Yeh, Hung-jen, and 葉宏仁. "Electronic Speckle Pattern Interferometry Applied to the Three-dimensional Displacement Measurement in Sandwich Plates with Insert and Potting Materials." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/13211310784373849692.

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碩士
國立中正大學
機械工程所
94
Sandwich honeycomb structures are used extensively for aircraft structures and flying vehicles, due to which have the advantage of characteristic for low mass and could be accept higher strength, and structure of the sandwich honeycomb plate with potting material and insert which can increase the strength of the structure, improve the local stress concentration and increase the loading point. This research presents the construction and operation of an electronic speckle pattern interferometry (ESPI) applied to sandwich plates with inserts. Proposed ESPI is a full-field and non-destructive testing that can measures tiny out-of-plane and in-plane displacement in the elastic region. The experimental construction is to integrate out-of-plane and in-plane measurement into an optical system, to measure the three-dimensional displacement of the sandwich plates. There are two main results of the experiment. The first result indicates that the strength of the sandwich plate will increase as the core thickness is increasing, but the displacement will decrease. The second result indicates that the displacement will decrease as the diameter of insert is increasing, but the strength will increase. For validation purpose, the analytical analysis was introduced to compare with the result of ESPI. Comparison between the results of ESPI and analytical revealed a convincing agreement. The results of this study could be applied on designing the sandwich structure with insert in the future.
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Liu, Yan Fu, and 劉彥甫. "Digital Speckle Pattern Phase Shift Shearography Applied to the Out-of-Plane Strain Measurement of Sandwich Plates with Insert/Potting Materials." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/06239108268955106885.

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碩士
國立中正大學
機械系
93
Abstract Honeycomb sandwich structures are used extensively for lightweight spacecraft, aircraft structures, owing to the advantage of the characteristics of low mass and high compressive strength; matching insert and potting material to strengthen its structural strength. A digital shearographic technique is a tool well-suited for precision measurement of strain and is a nondestructive testing technology. But the fringe patterns of shearography are not good. A phase-shifting technique is incorporated and demonstrated to yield good quality fringe patterns and effective to solve this question. But algorithm of phase-shifting is based on arctangent function, phase distribution is to place in -π/2~π/2, thus it must to use phase unwrapping technology to get full-field and continuous phase messages. The major purpose of this thesis is to produce a measuring system of digital phase shifting shearography, mainly including the piezoelectric transducer, the servo controller, the Michelson shearing mechanism, the image processing system and loading system, and we prove the practicability of Macy algorithm by program simulation, and examine the influence after applying noise. We use the four-step phase shifting method to obtain phase map and out of plane strain ( ) of honeycomb sandwich plate which including insert/potting material, and proceed phase expansion by Macy algorithm. Finally, comparing out of plane strain with shearography shows about 2% to 7% difference.
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Mariz, Marcos João Mota Leite Machado. "Ocular drug delivery insert technology: from polymer synthesis to in vitro testing." Doctoral thesis, 2018. http://hdl.handle.net/10316/87591.

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Tese de Doutoramento em Engenharia Química, apresentada ao Departamento de Engenharia Química da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Glaucoma é uma doença crónica que afeta cerca de 100 milhões de pessoas em todo o mundo e exige a administração continuada de fármacos. O sucesso do tratamento depen-de muito do próprio doente, no sentido em que é ele quem tem de instilar as gotas no pró-prio olho – 1 ou 2 vezes por dia. No entanto, como o glaucoma crónico é assintomático, a maioria dos doentes não cumpre a posologia correta, por esquecimento, ou desiste do tra-tamento, devido à elevada frequência de aplicações. Uma outra situação em que é reconhecida a dificuldade em cumprir a posologia pres-crita, está relacionada com as medidas profiláticas no pós-operatório de cirurgias oculares. Após uma cirurgia ocular, é pedido ao paciente que instile gotas de pelo menos 2 colírios – um, contendo um antibiótico e outro, um anti-inflamatório – em horários diferentes, várias vezes ao dia, por um período de 2-3 semanas. A solução para estes problemas na administração de gotas nos olhos, passa por de-senvolver um dispositivo que, quando colocado no olho, liberte um ou mais fármacos de forma controlada ao longo de várias semanas, em situações agudas, ou vários meses, para patologias crónicas. No trabalho de investigação aqui apresentado, foram desenvolvidos sistemas poliméricos com o objetivo de cumprirem com os requisitos necessários para a sua aplicação como insertos oftálmicos para libertação controlada de fármacos. O desenvolvimento da tecnologia, registada como Ineye®, baseou-se na estratégia de “Quality by Design” (QbD). Um dos elementos chave dessa estratégia é a definição do “Quality Target Product Profile” (QTPP), no qual se define o perfil de qualidade necessário para que o produto cumpra com o objetivo proposto de forma segura e eficaz. A seleção dos polímeros a utilizar na preparação dos insertos oculares, foi então baseada nesses pres-supostos e, após uma seleção inicial teórica baseada no estado atual do conhecimento, foi decidido preparar copolímeros de poli(ε-caprolactona)-poli(etileno glicol) (PCL/PEG). Es-tes mate-riais, de reconhecida biocompatibilidade e com várias aplicações, já documenta-das, na libertação controlada de fármacos, incluindo para aplicação ocular, aliam a hidrofo-bicidade e resistência mecânica de um poliéster, a PCL, com o caráter hidrofílico e plastifi-cante de um poliéter, o PEG. A elevada miscibilidade dos dois compostos permitiu preparar copolímeros com uma gama muito alargada de percentagens de PEG. A síntese deste copolímeros foi feita por reação do monómero ε-caprolactona, um és-ter cíclico, segundo o mecanismo reacional de polimerização por abertura de anel (ROP). Para garantir a formação de copolímeros em bloco (PCL-PEG-PCL), a proporção desejada de PEG foi adicionada no início da ROP. Para além de variar a proporção PCL/PEG, foram também sintetizados copolímeros utilizando PEG de diferentes pesos moleculares e adicio-nado um extensor de cadeia e reticulante, o diisocianato de hexametileno. Numa abordagem de QbD, fez-se uma avaliação de risco para determinar quais os pa-râmetros críticos do processo (CPP) da síntese por ROP. Foi feita uma exaustiva bateria de testes durante a qual se avaliou o impacto da temperatura e duração da síntese, da percen-tagem e peso molecular de PEG e da proporção catalisador/reagentes no peso molecular e nas propriedades térmicas e mecânicas dos copolímeros obtidos. Os resultados apontam para a percentagem de PEG como o principal CPP, concluindo-se que será necessário, aquando da produção à escala industrial, arranjar mecanismos de monitorização e controlo da percentagem de PEG. Definidas as condições ideais de síntese, prepararam-se insertos a partir de formula-ções distintas para avaliar algumas das propriedades biorrelevantes destes materiais – a energia de superfície, a absorção de água, a perda de massa, o pH da superfície e o seu im-pacto no pH do fluido lacrimal, a resistência à rutura e a biocompatibilidade. Os resultados permitiram selecionar várias formulações com potencial para serem utilizadas como insertos oculares e excluir outras que não cumpriam com alguns requisitos. Os polímeros mais promissores foram então utilizados para preparar diferentes siste-mas de libertação controlada de vários fármacos e a cinética de libertação foi estudada in vitro. Os testes permitiram relacionar a composição e a arquitetura do Ineye® com os perfis de libertação, através de vários modelos matemáticos, alguns desenvolvidos especificamen-te para este trabalho. Obtiveram-se tempos de libertação dos fármacos a variar entre 1 se-mana e 6 meses tanto em regime de difusão de acordo com a lei de Fick como de forma constante. Como resultado desta investigação, foi adquirido conhecimento que garante o contro-lo sobre a tecnologia desenvolvida nas suas múltiplas facetas - na síntese, nas principais características dos polímeros e na libertação controlada de vários fármacos. Assim, poder-se-á preparar, no futuro, o Ineye® adequado para cada patologia ocular, proporcionando a libertação de um ou mais fármacos na quantidade, taxa e duração necessários, melhorando a eficácia do tratamento e por conseguinte a qualidade de vida das pessoas.
Glaucoma is a chronic disease that affects around 100 million people worldwide and requires continued administration of drugs. The success of the treatment depends mainly on the patient himself, in the sense that he has to instill the drops into his own eye - 1 or 2 times a day. However, since chronic glaucoma is asymptomatic, most patients do not fol-low the correct posology, because of forgetfulness, or withdraw from treatment due to the high frequency of applications. Another situation, known by its difficulty in complying with the prescribed dosage, is the one related to prophylactic measures in the postoperative period of ocular surgeries. After an eye surgery, the patient is asked to instill drops of at least 2 eye drops – one con-taining an antibiotic and another, an anti-inflammatory – at different times, several times a day for a period of 2-3 weeks. The solution to these problems in the administration of eye drops is to develop a de-vice which, when placed in the eye, releases one or more drugs in a controlled way over several weeks, for acute situations, or several months, for chronic conditions. In the re-search work presented here, polymeric systems were developed in order to comply with the necessary requirements for their application as ophthalmic inserts for controlled drug re-lease. The development of the technology, registered as Ineye®, was based on the strategy of Quality by Design (QbD). One of the key elements of this strategy is the definition of the Quality Target Product Profile (QTPP), which defines the quality profile necessary for the product to meet its intended purpose in a safe and effective manner. The selection of the polymers to be used in the preparation of ocular inserts was then based on these as-sumptions and, after an initial theoretical selection based on the current state of the art, it was decided to prepare poly (ε-caprolactone) -poly (ethylene glycol) copolymers (PCL / PEG). These materials, of recognized biocompatibility and with various applications in the controlled release of drugs, already documented, including for ocular application, combine the hydrophobicity and mechanical strength of a polyester, PCL, with the hydrophilic and plasticizing character of a polyether, PEG. The high miscibility of the two compounds al-lowed the pre-paration of copolymers with a wide range of PEG percentages. The synthesis of these copolymers was carried out by reacting the ε-caprolactone mo-nomer, a cyclic ester, through the ring-opening polymerization (ROP) reaction mechanism. To ensure the formation of block copolymers (PCL-PEG-PCL), the desired ratio of PEG was added at the start of ROP. In addition to varying the PCL/PEG ratio, copolymers were also synthesized using PEGs of different molecular weights and a chain extender and crosslinker, hexamethylene diisocyanate, was added. In a QbD approach, a risk assessment was performed to determine the critical process parameters (CPP) of ROP synthesis. An exhaustive test battery was carried out during which the impact of the temperature and duration of the synthesis, the percentage and mo-lecular weight of PEG and the catalyst / reagent ratio on the molecular weight and on the thermal and mechanical properties of the copolymers obtained was evaluated. The results point to the percentage of PEG as the main CPP, concluding that it will be necessary, dur-ing the production on an industrial scale, to arrange mechanisms for monitoring and con-trolling the percentage of PEG. Once the optimal synthesis conditions were defined, inserts were prepared from dis-crete formulations to evaluate some of the biorelevant properties of these materials - surface energy, water absorption, mass loss, surface pH and its impact on pH lacrimal fluid, re-sistance to breaking and biocompatibility. The results allowed to select several formulations with potential to be used as ocular inserts and to exclude others that did not fulfil some requirements. The most promising polymers were then used to prepare different controlled drug de-livery systems and the release kinetics were studied in vitro. The tests allowed to relate the composition and architecture of the Ineye® with the release profiles, using various mathe-matical models, some developed specifically for this work. The drug release periods ranged from 1 week to 6 months either on a diffusion following Fick’s Law or on a constant deliv-ery rate. As a result of this research, knowledge has been acquired that ensures control over the technology developed in its multiple facets – in the synthesis, in the main characteristics of the polymers and in the controlled release of several drugs. Thus, a tailored Ineye® suit-able for each ocular pathology can be prepared in the future, providing the release of one or more drugs in the required quantity, rate and duration, improving the effectiveness of the treatment and therefore the quality of people’s life.
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