Home  About us  Contact
 

Fabrication Methods (fabrication + methods)

Distribution by Scientific Domains
Polymers and Materials Science50%
Chemistry25%

Selected Abstracts

Qualitative and quantitative fracture analyses of high-strength ceramics

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2 2009
Marit Řilo
The aims of this study were to assess the applicability and repeatability of qualitative and quantitative analyses of the fracture patterns of four different high-strength ceramics. Ten bar-shaped specimens of four high-strength ceramics with different material composition and fabrication methods had been fractured by three-point bending in water (n = 40). Commonly used fractographic patterns for brittle materials, such as mirror and mist, were used to characterize and quantify the fractured surfaces of these specimens. The analyses were performed twice, on separate occasions, by the same operator. Assessment of the association between fractographic patterns and fracture stress was carried out, and repeatability assessments of the measurements were performed. The fracture initiator site and the common fractographic markers surrounding this site were found in all specimens. Statistically significant correlations were found between certain fracture patterns and stress at fracture. The repeatability of the measurements of the different fractographic patterns varied among the materials. Fracture analyses seem applicable as a tool to determine the fracture initiation site and to estimate the force vectors involved in the fracture of dental high-strength ceramics. [source]

Structural Fabrication and Functional Modulation of Nanoparticle,Polymer Composites

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2010
Hao Zhang
Abstract This review article summarizes recent progress in the fabrication methodologies and functional modulations of nanoparticle (NP),polymer composites. On the basis of the techniques of NP synthesis and surface modification, the fabrication methods of nanocomposites are highlighted; these include surface-initiated polymerization on NPs, in situ formation of NPs in polymer media, and the incorporation through covalent linkages and supramolecular assemblies. In these examples, polymers are foremost hypothesized as inert hosts that stabilize and integrate the functionalities of NPs, thus improving the macroscopic performance of NPs. Furthermore, due to the unique physicochemical properties of polymers, polymer chains are also dynamic under heating, swelling, and stretching. This creates an opportunity for modulating NP functionalities within the preformed nanocomposites, which will undoubtedly promote the developments of optoelectronic devices, optical materials, and intelligent materials. [source]

In-Film Bioprocessing and Immunoanalysis with Electroaddressable Stimuli-Responsive Polysaccharides

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2010
Xiaohua Yang
Abstract Advances in thin-film fabrication are integral to enhancing the power of microelectronics while fabrication methods that allow the integration of biological molecules are enabling advances in bioelectronics. A thin-film-fabrication method that further extends the integration of biology with microelectronics by allowing living biological systems to be assembled, cultured, and analyzed on-chip with the aid of localized electrical signals is described. Specifically, the blending of two stimuli-responsive film-forming polysaccharides for electroaddressing is reported. The first, alginate, can electrodeposit by undergoing a localized sol,gel transition in response to electrode-imposed anodic signals. The second, agarose, can be co-deposited with alginate and forms a gel upon a temperature reduction. Electrodeposition of this dual polysaccharide network is observed to be a simple, rapid, and spatially selective means for assembly. The bioprocessing capabilities are examined by co-depositing a yeast clone engineered to display a variable lymphocyte receptor protein on the cell surface. Results demonstrate the in-film expansion and induction of this cell population. Analysis of the cells' surface proteins is achieved by the electrophoretic delivery of immunoreagents into the film. These results demonstrate a simple and benign means to electroaddress hydrogel films for in-film bioprocessing and immunoanalysis. [source]

Low-Temperature-Grown Transition Metal Oxide Based Storage Materials and Oxide Transistors for High-Density Non-volatile Memory

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2009
Myoung-Jae Lee
Abstract An effective stacked memory concept utilizing all-oxide-based device components for future high-density nonvolatile stacked structure data storage is developed. GaInZnO (GIZO) thin-film transistors, grown at room temperature, are integrated with one-diode (CuO/InZnO),one-resistor (NiO) (1D,1R) structure oxide storage node elements, fabricated at room temperature. The low growth temperatures and fabrication methods introduced in this paper allow the demonstration of a stackable memory array as well as integrated device characteristics. Benefits provided by low-temperature processes are demonstrated by fabrication of working devices over glass substrates. Here, the device characteristics of each individual component as well as the characteristics of a combined select transistor with a 1D,1R cell are reported. X-ray photoelectron spectroscopy analysis of a NiO resistance layer deposited by sputter and atomic layer deposition confirms the importance of metallic Ni content in NiO for bi-stable resistance switching. The GIZO transistor shows a field-effect mobility of 30,cm2,V,1,s,1, a Vth of +1.2,V, and a drain current on/off ratio of up to 108, while the CuO/InZnO heterojunction oxide diode has forward current densities of 2,×,104,A,cm,2. Both of these materials show the performance of state-of-the-art oxide devices. [source]

SOFCo Planar Solid Oxide Fuel Cell

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2004
Liang A. Xue
SOFCo-EFS Holdings LLC has developed a multi-layer, planar solid oxide fuel cell (SOFC) stack that has the potential to provide superior performance and reliability at reduced costs. Our approach combines state-of-the-art SOFC materials with the manufacturing technology and infrastructure established for multi-layer ceramic (MLC) packages for the microelectronics industry. With the proper selection of SOFC materials, implementation of MLC fabrication methods offers unique designs for stacks. Over the past two years, substantial progress has been made in the design and manufacturing development of our second-generation stack. Effective stack and manifold seals have been developed. Cell performance has been improved and relatively low non-cell contributions to stack resistance have been achieved. Stack development has been facilitated through the implementation of two key test methods: (1) a 10-cm single-cell test to bridge the gap in performance data obtained from button cell tests (used for cell R&D) and stack tests; and (2) a novel instrumented short stack (<5 cells) that allows for effective isolation of individual contributions to stack resistance. As a result of progress made to date, a clear pathway for improving stack performance has been established, thereby building confidence that commercial stack performance targets will be reached. [source]

Porous anodic alumina microreactors for production of hydrogen from ammonia

AICHE JOURNAL, Issue 4 2004
Jason C. Ganley
Abstract The synthesis and properties are described of a ruthenium-impregnated anodic aluminum catalyst for use in microreactors for the production of hydrogen from an ammonia feed. The catalyst structure was synthesized using microelectric discharge machining to create a series of 300 × 300-,m posts on an aluminum substrate. The posts were anodized to yield a 60-,m covering of anodic alumina, with an average surface area of 16 m2/gm and an average pore size of 50 nm. Ruthenium metal was dispersed on the alumina using conventional wet impregnation. A 0.9 × 0.9-cm reactor containing 250 posts decomposed 95% of anhydrous ammonia at 650°C to yield 15 sccm of hydrogen. A possible application of these microreactor fabrication methods is hydrogen generation for fuel cells in mobile power production. 2004 American Institute of Chemical Engineers AIChE J, 50:829,834, 2004 [source]

Working with Wiki, by Design

ARCHITECTURAL DESIGN, Issue 5 2006
Andrew Burrow
Abstract Andrew Burrow and Jane Burry explain the use of online platforms, such as wiki, employed by the Spatial Information Architecture Laboratory (SIAL) at RMIT University in Melbourne. As they demonstrate, these platforms enable projects whose participants span the globe, in turn situating SIAL within an internationally distributed design research network incorporating diverse forms of expertise. This includes the academic research under way at SIAL, much of which is done collaboratively with various other design and research entities, as well as the international work of SIAL's director Mark Burry, who has been developing innovative design and fabrication methods for the completion of Gaudí's complex proposal for the Sagrada Família church. SIAL's wiki platform collapses geographic and temporal distance to allow geographically dispersed agents to collaborate in unprecedented ways, integrating widely diverse sets of knowledge into the design process. Copyright © 2006 John Wiley & Sons, Ltd. [source]

State of the art of carbon molecular sieves supported on tubular ceramics for gas separation applications

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2010
Kelly Briceńo
Abstract During recent years, research into alternative power generation and less polluting vehicles has been directed towards the fabrication of compact and efficient devices using hydrogen fuel cells. As a compact viable proposal, membrane reactors (MR) have been studied as means of providing a fuel cell with an on-board supply device for pure hydrogen streams obtained by reforming hydrocarbons. However, the development of MRs is strongly dependant on the membrane having high permeation flux and high selectivity ratios towards H2 in a mixture of gases. To meet this need, carbon membranes are proposed materials, which have pores that are the same size as the kinetic diameters of syngases. These would provide an alternative to polymers, metals and ceramics in MR applications. Moreover, a tubular shape is a highly recommended configuration for achieving a compact and large reaction surface area. However, it is not easy to obtain a supported and amorphous carbon layer from polymer pyrolysis because the fabrication methods, the type of precursor material, characteristics of the support and pyrolysis conditions are all closely connected. The combination of all these factors and the stability problems of carbon membranes have limited the use of carbon molecular sieves (CMS) in large-scale applications. This review attempts to provide an overview of the use of carbon membranes in MRs for gas separation. It also reviews the advances in the materials, fabrication methods and characterisation techniques of specific supported carbon molecular sieve membranes that have been supported on tubular carriers so they can take advantage of the high permeation and selectivity values previously reported for unsupported CMS. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]