Die Arbeit führt Methoden zur Durchführung von Zugversuchen und bruchmechanischen Versu-chen ein und liefert mechanische Kennwerte für zwei kohlenstoffgebundene FFW im Bereich von RT bis 1500°C. Dafür standen ein grobkörniges MgO-C und ein feinkörniges Al2O3-C zur Ver-fügung. Die Werkstoffe zeigten bis 1200°C keine Duktilität und sprachen spröde. Die Schädigung erfolgte ausschließlich durch Risswachstum. Dieses fand beim MgO-C temperaturunabhängig auf Grund der rissbehafteten Mikrostruktur durch stabiles Risswachstum bereits vorhandener Risse statt. Es kam dabei zur Bildung von Rissnetzwerken sowie zu zahlreichen energiedissipierenden Prozessen. Beim Al2O3-C trat be RT instabiles Risswachstum auf. Bei hohen Temperaturen kam es durch thermisch aktivierte Prozesse zu duktilem Verhalten und stabilem Risswachstum. Beim grobkörnigen MgO-C wurden große Verformungen durch das starre Oxidgerüst verhindert. Zu-sätzlich zeigten die Werkstoffe auf Grund ihrer Mikrostruktur eine Zunahme der Festigkeit mit steigender Temperatur. Aus den Versuchen wurde ein Heißpressverfahren zur Herstellung von gradierten Werkstoffen abgeleitet.:1 Einleitung 2 Grundlagen 2.1 Feuerfestwerkstoffe 2.1.1 Einsatz und Beanspruchung von FFW 2.1.2 Einteilung von FFW 2.2 Kohlenstoffgebundene FFW 2.2.1 Kohlenstoff und seine Terminologie 2.2.2 Grundlegende Eigenschaften kohlenstoffgebundener FFW 2.2.3 Anwendungen kohlenstoffgebundener FFW 2.2.4 Aufbau und Mikrostruktur kohlenstoffgebundener FFW 2.2.5 Herstellungsparameter kohlenstoffgebundener FFW 2.2.6 Chemische Eigenschaften kohlenstoffgebundener FFW 2.3 Mechanische Eigenschaften kohlenstoffgebundener FFW 2.3.1 Mechanische Eigenschaften kohlenstoffgebundener FFW bei RT 2.3.2 Mechanische Eigenschaften kohlenstoffgebundener FFW bei HT 2.4 Grundlagen zur Werkstoffprüfung bei RT und hohen Temperaturen 2.4.1 Streuung und Einfluss der Probengröße 2.4.2 Belastungsrate 2.4.3 Zugversuche 2.4.4 Druckversuche 2.4.5 Biegeversuche 2.4.6 Bruchmechanische Untersuchungen 2.4.7 Temperaturwechselbeständigkeit 2.4.8 Kriechen 2.4.9 Spannungsrelaxation 2.4.10 Härtemessung 2.4.11 Hochtemperaturprüfung in Kaltkammerofen mit induktiver Heizung 2.4.12 Temperaturmessung mit Thermoelement, Pyrometrie, Thermographie 2.4.13 Bestimmung elastischer Konstanten mittels akustischer Methoden 2.4.14 Optische in situ Schadensbeschreibung mittels Mikroskopie und DIC 2.5 Heißpressverfahren 3 Experimentelles 3.1 Werkstoffe 3.1.1 Kohlenstoffgebundenes Magnesiumoxid (MgO-C) 3.1.2 Kohlenstoffgebundenes Aluminiumoxid (Al2O3-C) 3.1.3 Graphit (ISEM 8) 3.2 Mechanische Tests 3.2.1 Prüfmaschine für Druck- und Biegeversuche 3.2.2 Prüfmaschine für Zug-Druck-Versuche 3.2.3 Probengeometrien 3.2.4 Druckversuche 3.2.5 Biegeversuche 3.2.6 Bruchmechanische Versuche 3.2.7 Versuche mit Zugbeanspruchung 3.2.8 Versuchsabläufe der Hochtemperaturversuche 3.2.9 Temperaturmessung mittels Thermographie 3.3 Weitere Versuchsmethoden 3.3.1 Mikrostrukturuntersuchung mittels Mikroskopie und Röntgenbeugung 3.3.2 Porositäts- und Dichtemessung 3.3.3 Härtemessung 3.3.4 Dynamischer E-Modul 4 Methodische Erkenntnisse und Voruntersuchungen 4.1 Temperaturmessung und -verteilung 4.1.1 Temperaturmessung mittels Thermoelement und Pyrometer 4.1.2 Emissionskoeffizient und Probenbeschichtung 4.1.3 Temperaturverteilung 4.2 Dehnungsmessung 4.3 Zugversuche an Keramiken 4.3.1 Übertragung von Zugkräften 4.3.2 Axialität in Zugversuchen 4.4 Bruchmechanische Versuche 4.4.1 Kerbeinbringung 4.4.2 Überprüfung des optischen Messsystems 4.4.3 Bestimmung der Risslänge während des Versuchs 4.5 Überprüfung der Messmethodik mit dem Referenzwerkstoff Graphit ISEM-8 5 Ergebnisse 5.1 Mikrostrukturbeschreibung der untersuchten FFW 5.1.1 Mikrostruktur des MgO-C’s 5.1.2 Mikrostruktur des Al2O3-C’s 5.2 Mechanisches Verhalten bei RT 5.2.1 Mechanisches Verhalten von MgO-C bei RT 5.2.2 Mechanisches Verhalten von Al2O3-C bei RT 5.3 Mechanische Eigenschaften bei HT 5.3.1 Mechanisches Verhalten von MgO-C bei HT 5.3.2 Mechanisches Verhalten von Al2O3-C bei HT 5.4 Heißpressverfahren für kohlenstoffgebundene FFW 5.4.1 Beschreibung des Heißpressverfahrens 5.4.2 Physikalische Eigenschaften und Mikrostruktur des Presslings 5.4.3 Mechanische Eigenschaften des Presslings 6 Diskussion 7 Zusammenfassung und Ausblick Literatur Anhang

Compósitos verdes são caracterizados por possuir matriz polimérica e reforço derivado de fontes naturais. Polímeros derivados do petróleo não são biodegradáveis e possuem solventes orgânicos na sua composição. Solventes orgânicos são tóxicos e poluentes. A poliuretana derivada do óleo de mamona é derivada de fonte renovável, biodegradável e não possui solventes orgânicos em sua composição. A casca de pinhão é um resíduo do pinhão, semente do pinheiro de Paraná. O objetivo desse trabalho é desenvolver e caracterizar o compósito de casca de pinhão com PU derivada do óleo de mamona. A fibra foi caracterizada quimicamente, por FTIR, TGA e MEV. A PU foi caracterizada por ensaio de resistência à flexão, FTIR e TGA e os compósitos, por testes de densidade, absorção de água, inchamento em espessura, resistência à flexão de três pontos, FTIR e TGA. A superfície da fratura foi avaliada por MEV e a homogeneidade dos compósitos por perfil de densidade e raios-X. O compósito de 35%PU apresentou resistência à flexão de 51,55 MPa, densidade de 1018 kg/m³, absorção de água em 24 horas de 7,95% e inchamento em espessura em 24 horas de 5,36%. O material apresenta propriedades mecânicas apropriadas para uso em mobiliário e artesanato. / Polymeric composites reinforced with natural fibers are denominated green composites. Polymers comes from petroleum source, a non-biodegradable material and has volatile organic compounds, VOC, in its composition. Organic solvent are toxics and pollute the environment. The Polyurethane derived from castor oil is polymer produced from renewable sources, biodegradable material and there are no VOC in its composition. Araucária pine nut shell is a residue from its Araucaria pine seed. The aim of this work is to develop and characterize composites of pine nut shell with polyurethane derived from castor oil. The fiber was chemically characterized, thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). PU was characterized by flexural strength, FTIR and TGA and composites was characterizes by density test, water absorption and swelling in thickness, flexural strength, FTIR, TGA. SEM evaluated the fracture surface and X-ray and vertical density profile verified the composites homogeneity. 35%PU composites presented flexural strength of 51,55 MPa, density of 1018 kg/m³, 7,95% of 24h water absorption and 5,36% of 24h swelling in thickness of. The material exhibits properties suitable for use in furniture and handicrafts.

Pesquisa realizada para analisar o compósito de solo de decapagem (SD) considerado resíduos nas jazidas de minérios, em especial de calcário do município de Almirante Tamandaré, da Região Metropolitana de Curitiba neste trabalho, juntamente com o lodo e sedimentos de dragagem marinha do Porto de Antonina, no Estado do Paraná, e o uso cal virgem comum, como aglomerante pertencente à região de Almirante Tamandaré. Foram utilizados vários teores dos materiais para a determinação de 12 (doze) compósitos. Para o solo de decapagem os teores variaram entre 30% a 60%, para o material de dragagem os teores variaram entre 20% a 50% e o teor de aglomerante de cal virgem comum variou entre 15% a 30%. Foram moldadas idades de cura de 3 dias, 7, 14, 28, 60, 90, 180 e 365 dias. O aumento da resistência à compressão durante a cura foi proveniente das reações químicas das partículas sólidas das matérias-primas em ambiente alcalino gerando novas formações amorfas. Também foram analisados os materiais nos métodos de MEV com EDS, DRX e FRX, para a obtenção da composição química e formação estrutural dos novos compósitos. Todos os resultados da resistência à compressão uniaxial, com 28 dias de cura ao meio ambiente das 12 (doze) composições, obtiveram resultados médios de 7,7 MPa, atendendo satisfatoriamente a norma NBR 7170:1983 que determina a resistência à compressão igual ou acima de 4,0 MPa, destinada à produção de materiais de construção para alvenaria de vedação, sem fins estruturais. Comprovando o uso desses compósitos em materiais de construção civil, principalmente para os segmentos de blocos ou tijolos de vedações, sem fins estruturais, sem a necessidade de cozimento ou empreendimento de energia calorífica para a cura das peças, contribuindo para o meio ambiente e a sustentabilidade ambiental. / Research conducted to analyze the composite with pickling soil (SD), considered waste in mineral deposits, especially of limestone in the city of Almirante Tamandaré, the Metropolitan Region of Curitiba in this work, along with the sludge and marine dredging sediment from the Port of Antonina, State of Paraná, and use the common quicklime as binder belonging to the same region of Almirante Tamandaré. Various amounts of materials were used for the determination of twelve (12) composites. For the stripping soil content ranged from 30% and 60%, for the dredging material contents ranged from 20% and 50% and binder common quicklime content ranged from 15% to 30%. Were molded curing ages of 3 days, 7, 14, 28, 60, 90, 180 and 365 days. The increase in compressive strength during curing was derived from the chemical reactions of solid particles of raw materials in alkaline environment generating the new amorphous formations. Also the raw materials were analyzed in the SEM with EDS method, DRX and FRX, to obtain the chemical composition and formation structures of the new composite. All results of the uniaxial compressive strength, with 28 days of curing the environment of the twelve (12) compositions, obtained average results of 7.7 MPa, satisfactorily meeting the NBR 7170:1983 standard that determines the resistance to compression equal or above 4.0 MPa, for the production of building materials for sealing masonry without structural purposes. Proving the use of these composites in construction materials, especially for thread block or brick fences without structural purposes, without the need for cooking or heating energy project for the healing of parts, contributing to the environment and sustainability Environmental.

Indiana University-Purdue University Indianapolis (IUPUI) / Topology optimization allows designers to obtain lightweight structures considering the binary distribution of a solid material. The introduction of cellular material models in topology optimization allows designers to achieve significant weight reductions in structural applications. However, the traditional topology optimization method is challenged by the use of cellular materials. Furthermore, increased material savings and performance can be achieved if the material and the structure topologies are concurrently designed. Hence, multi-scale topology optimization methodologies are introduced to fulfill this goal. The objective of this investigation is to discuss and compare the design methodologies to obtaining optimal macro-scale structures and the corresponding optimal meso-scale material designs in continuum design domains. These approaches make use of homogenization theory to establish communication bridges between both material and structural scales. The periodicity constraint makes such cellular materials manufacturable while relaxing the periodicity constraint to achieve major improvements of structural performance. Penalization methods are used to obtain binary solutions in both scales. The proposed methodologies are demonstrated in the design of stiff structure and compliant mechanism synthesis. The multiscale results are compared with the traditional structural-level designs in the context of Pareto solutions, demonstrating benefits of ultra-lightweight configurations. Errors involved in the mult-scale topology optimization procedure are also discussed. Errors are mainly classified as mesh refinement errors and homogenization errors. Comparisons between the multi-level designs and uni-level designs of solid structures, structures using periodic cellular materials and non-periodic cellular materials are provided. Error quantifications also indicate the superiority of using non-periodic cellular materials rather than periodic cellular materials.

Indiana University-Purdue University Indianapolis (IUPUI) / This paper presents a novel approach of particulate material (soot) measurement in a Diesel particulate filter using Electrical Capacitance Tomography. Modern Diesel Engines are equipped with Diesel Particulate Filters (DPF), as well as on-board technologies to evaluate the status of DPF because complete knowledge of DPF soot loading is very critical for robust efficient operation of the engine exhaust after treatment system. Emission regulations imposed upon all internal combustion engines including Diesel engines on gaseous as well as particulates (soot) emissions by Environment Regulatory Agencies. In course of time, soot will be deposited inside the DPFs which tend to clog the filter and hence generate a back pressure in the exhaust system, negatively impacting the fuel efficiency. To remove the soot build-up, regeneration of the DPF must be done as an engine exhaust after treatment process at pre-determined time intervals. Passive regeneration use exhaust heat and catalyst to burn the deposited soot but active regeneration use external energy in such as injection of diesel into an upstream DOC to burn the soot. Since the regeneration process consume fuel, a robust and efficient operation based on accurate knowledge of the particulate matter deposit (or soot load)becomes essential in order to keep the fuel consumption at a minimum. In this paper, we propose a sensing method for a DPF that can accurately measure in-situ soot load using Electrical Capacitance Tomography (ECT). Simulation results show that the proposed method offers an effective way to accurately estimate the soot load in DPF. The proposed method is expected to have a profound impact in improving overall PM filtering efficiency (and thereby fuel efficiency), and durability of a Diesel Particulate Filter (DPF) through appropriate closed loop regeneration operation.

Indiana University-Purdue University Indianapolis (IUPUI) / Dicalcium phosphate dihydrate (DCPD) cements have been used for bone repair due to its excellent biocompatibility and resorbability. However, DCPD cements are typically weak and brittle. To overcome these limitations, the sodium citrate used as a setting regulator and the coating of poly-L-lactide acid (PLLA) technique have been proposed in this study. The first purpose of this thesis is to develop composite PLLA/DCPD scaffolds with enhanced toughness by PLLA coating. The second purpose is to examine the biocompatibility of the scaffolds. The final purpose is to investigate the degradation behaviors of DCPD and PLLA/DCPD scaffolds. In this experiment, DCPD cements were synthesized from monocalcium phosphate monohydrate (MCPM) and 𝛽-tricalcium phosphate (𝛽 –TCP) by using deionized water and sodium citrate as liquid components. The samples were prepared with powder to liquid ratio (P/L) at 1.00, 1.25 and 1.50. To fabricate the PLLA/DCPD composite samples, DCPD samples were coated with 5 % PLLA. The samples were characterized mechanical properties, such as porosity, diametral tensile strength, and fracture energy. The mechanical properties of DCPD scaffolds with and without PLLA coating after the in vitro static degradation (day 1, week1, 4, and 6) and in vitro dynamic degradation (day 1, week 1, 2, 4, 6, and 8) were investigated by measuring their weight loss, fracture energy, and pH of phosphate buffer solution. In addition, the dog bone marrow stromal stem cells (dBMSCs) adhesion on DCPD and PLLA/DCPD composite samples were examined by scanning electron microscopy. The cell proliferation and differentiation in the medium conditioned with DCPD and PLLA/DCPD composite samples were studied by XTT (2,3-Bis(2-methoxy-4- nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt), and alkaline phosphatase (ALP) assay, respectively. The addition of sodium citrate and PLLA coating played a crucial role in improving the mechanical properties of the samples by increasing the diametral tensile strength from 0.50 ± 0.15 MPa to 2.70 ± 0.54 MPa and increasing the fracture energy from 0.76 ± 0.18 N-mm to 12.67 ± 4.97 N-mm. The DCPD and PLLA/DCPD composite samples were compatible with dBMSCs and the cells were able to proliferate and differentiate in the conditioned medium. The degradation rate of DCPD and PLLA/DCPD samples were not significant different (p > 0.05). However, the DCPD and PLLA/DCPD composite samples those used sodium citrate as a liquid component was found to degrade faster than the groups that use deionized water as liquid component

Indiana University-Purdue University Indianapolis (IUPUI) / The passive properties of the venous wall are important in the development of venous pathology. Increase in venous pressure due to retrograde flow (reflux) and obstruction of venous flow by intrinsic and extrinsic means are the two possible mechanisms for venous hypertension. Reflux is the prevailing theory in the etiology of venous insufficiency. The objective of this thesis is to quantify the passive biomechanical response and structural remodeling of veins subjected to chronic venous reflux and hypertension. To investigate the effects of venous reflux on venous mechanics, the tricuspid valve was injured chronically in canines by disrupting the chordae tendineae. The conventional inflation-extension protocol in conjunction with intravascular ultrasound (IVUS) was utilized to investigate the passive biomechanical response of both control common iliac veins (from 9 dogs) and common iliac veins subjected to chronic venous reflux and hypertension (from 9 dogs). The change in thickness and constituent composition as a result of chronic venous reflux and hypertension was quantified using multiphoton microscopy (MPM) and histological evaluation. Biomechanical results indicate that the veins stiffened and became less compliant when exposed to eight weeks of chronic venous reflux and hypertension. The mechanical stiffening was found to be a result of a significant increase in wall thickness (p < 0.05) and a significant increase in the collagen to elastin ratio (p < 0.05). After eight weeks of chronic reflux, the circumferential Cauchy stress significantly reduced (p < 0.05) due to wall thickening, but was not restored to control levels. This provided a useful model for development and further analysis of chronic venous insufficiency and assessment of possible intervention strategies.