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Single Coating (single + coating)
Selected AbstractsDesign, Preparation, and Characterization of Graded YSZ/La2Zr2O7 Thermal Barrier CoatingsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 6 2010Hongfei Chen Large-area spallation and crack formation during service are big problems of plasma-sprayed thermal barrier coatings (TBCs), owing to their weak bond strengths and high residual stresses. Functional gradient TBCs with a gradual compositional variation along the thickness direction are proposed to mitigate these problems. In this paper, a six-layer structured TBC composed of Y2O3 partially stabilized ZrO2 (YSZ) and La2Zr2O7 (LZ), was prepared by plasma spraying with dual powder feeding ports. This coating had a gradient composition and function. Thermal conductivity of the coating was comparable with that of a single LZ coating while the coefficient of thermal expansion was nearly equal to that of YSZ single coating. The experiment was conducted to compare the thermal shock resistance of a graded coating with a conventional YSZ/LZ double-layer system. Changes in weight and morphology of specimens before and after thermal shock tests were analyzed. Results demonstrated that the thermal shock resistance of the graded coating was superior to the double-layer coating. Typically, a barely visible pimple-like spallation was present on the surface of the graded coating after 21 cycles. On the other hand, obvious delamination was observed for a double-layer coating after six to seven cycles. Special focus was also placed on a comparative investigation of stresses that are closely related to spallation via the use of numerical simulation. [source] Calcium Phosphate Bioceramics with Various Porosities and Dissolution RatesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2002Soon-Ho Kwon Porous bioceramics, such as hydroxyapatite (HA), tricalcium phosphate (TCP), and biphasic HA/TCP, were fabricated using the polyurethane sponge technique. The porosity of the ceramics was controlled by a multiple coating of the porous body. When a porous body was produced by a single coating, the porosity was ,90%, and the pores were completely interconnected. When the sintered body was coated five times after the porous network had been made, the porosity decreased to 65%. As the porosity decreased, the strength increased exponentially. The TCP exhibited the highest dissolution rate in a Ringer's solution, and the HA had the lowest rate. The biphasic HA/TCP showed an intermediate dissolution rate. [source] Behavior of Cardiomyocytes and Skeletal Muscle Cells on Different Extracellular Matrix Components,Relevance for Cardiac Tissue EngineeringARTIFICIAL ORGANS, Issue 1 2007Karin Macfelda Abstract:, Myocardial cell transplantation in patients with heart failure is emerging as a potential therapeutic option to augment the function of remaining myocytes. Nevertheless, further investigations on basic issues such as ideal cell type continue to be evaluated. Therefore, the aim of our studies was to compare the performance of skeletal muscle cells and cardiomyocytes with respect to their proliferation rate and viability on different extracellular matrix components (EMCs). Rat cardiomyocytes (RCM) and rat skeletal muscle cells (RSMC) were cultured on EMCs such as collagen type I, type IV, laminin, and fibronectin. The components were used as "single coating" as well as "double coating." Proliferation rates were determined by proliferation assays on days 1, 2, 4, and 8 after inoculation of the cells. The most essential result is that collagen type I enhances the proliferation rate of RSMC but decreases the proliferation of RCM significantly. This effect is independent of the second EMC used for the double-coating studies. Other EMCs also influence cellular behavior, whereas the sequence of the EMCs is essential. Results obtained in our studies reveal the significant different proliferation behavior of RCM and RSMC under identical conditions. As skeletal muscle cells are also used in heart tissue engineering models, these results are essential and should be investigated in further studies to prove the applicability of skeletal muscle cells for heart tissue engineering purposes. [source] Transluzente oxidfaserverstärkte Glasmatrix-VerbundwerkstoffeMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 7 2003P. Fehling glass composites; fiber coating; atomic force microscopy; chemical vapour deposition Abstract Das Ziel der Untersuchungen ist die Entwicklung von transparenten Glasmatrix-Kompositen. Neben den mechanischen müssen dazu auch die optischen Eigenschaften der Komponenten aneinander angepaßt werden. Der Einfluß unterschiedlicher Faserbeschichtungen (Bornitrid-, Titandioxid-Einzelbeschichtung oder Bornitrid/Titandioxid-Doppelbeschichtung) auf die mechanischen und optischen Eigenschaften von Nextel 440-Faser verstärktem Glas wird untersucht. Mikromechanische Untersuchungen (push-in Tests) und 3-Punktbiegeversuche erbrachten die größte Verbesserung der Bruchzähigkeit für die Verbunde mit Bornitrid/Titandioxid-doppelbeschichteten Fasern. Die Verbunde mit Bornitrid bzw. Titandioxid Einzelschichten wurden durch Transmissionsmessungen im sichtbaren Spektralbereich charakterisiert. Translucent oxide fiber reinforced glasmatrix composites The aim of the work is the developement of transparent glass matrix composites. Therefore besides the mechanical properties also the optical properties of the components have to be adapted. In this study the influence of different fiber coatings (boron nitride, titanium oxide and a boron nitride/titanium oxide double coating) on the mechanical and optical properties of Nextel 440-fiber reinforced glass was investigated. Micromechanical investigations (push-in-tests) and 3-point-bending tests have shown the best improvement of the fracture toughness for the binary boron nitride/titanium oxide coating. For single coatings of boron nitride or titanium oxide the transparency was characterized by the transmission spectra. [source] | ||||||||||