We have developed a method of catalyst preparation for carbon nanotube (CNT) growth that uses solid-state diffusion to precipitate Co particles in a Cu matrix and control the size and size distribution of catalyst par...
We have developed a method of catalyst preparation for carbon nanotube (CNT) growth that uses solid-state diffusion to precipitate Co particles in a Cu matrix and control the size and size distribution of catalyst particles. Copper is an excellent electrical and thermal conductor, and has a small or negligible solubility for Co. Cu–Co alloys of approximately 5 atm% Co were formed in bulk by splat quenching the liquid alloy and on Si substrates by e-beam evaporation of the alloy, sputtering of the alloy, and sputter deposition of thin films of pure Cu and Co. The Co easily precipitates from dilute solutions of Cu–Co with heat treatment. These alloys and films were used to generate uniform distributions of Co precipitates, and CNTs were successfully grown by plasma enhanced chemical vapor deposition (PE-CVD) and thermal CVD on the materials. These alloys can be patterned by photolithography and sputtering in order to grow CNTs in defined locations. Therefore, the technique is amenable to very large scale silicon integration for field emission applications. The results of this work and data from field emission studies are presented herein.
A data model supporting the unification of the management of temporal XML document databases and version control, i.e., a Temporal Version Data Model (TVDM), is proposed. TVDM is temporally change-centric and represen...
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Research efforts in quality of service (QoS) management have usually addressed the problem under the network infrastructure perspective whereas a business-oriented perspective, named service quality management (SQM), ...
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Research efforts in quality of service (QoS) management have usually addressed the problem under the network infrastructure perspective whereas a business-oriented perspective, named service quality management (SQM), is being considered by industry. This paper point out differences and similarities between two approaches and addresses the main issues arising under SQM perspective. Here, QoS indicators and corresponding service levels are defined to provide a common understanding of service delivery, and a critical issue is to provide an effective way to evaluate them. Two evaluation modes are used: off-line and on-line. Off-line methods compute indicators values at the end of a pre-defined evaluation period, whereas on-line methods do it when a related event occurs. This work proposes an architecture for SQM systems and discusses the mechanisms for both off-line and on-line evaluation modes.
This paper focuses on implementation issues of a virtual environment to support the interaction with a coordinate measuring machine (CMM), which is used to measure dimensions and form of mechanical parts. First, it gi...
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This paper focuses on implementation issues of a virtual environment to support the interaction with a coordinate measuring machine (CMM), which is used to measure dimensions and form of mechanical parts. First, it gives an overview of the implementation, presenting the software "Avalon" and the basic architecture of the developed application. Then, it describes the execution environment, including the description of equipments and devices, characteristics and constraints, and system execution. Finally, it presents the conclusions of the work.
Information technology is providing manufacturers with additional flexibility with regard to their supply chain network choices. Our research studies supply chain network organization structures categorized by the org...
Information technology is providing manufacturers with additional flexibility with regard to their supply chain network choices. Our research studies supply chain network organization structures categorized by the organic and mechanistic management control structures. The structural impacts on cost and fill rate performance are studied in two-echelon and two-supply-chain network organization models under different market coordination conditions using system dynamic simulations. Our results show significant effects of demand and network structural factors, and their interactions, on these measures. As demand becomes dynamic, the cooperative interaction model, where supply chains cooperate to satisfy customer demand, is found to have better system performance than the competitive supply chain model. The analysis also suggests that increasing the responsiveness at the downstream plant is particularly important to the overall system performance improvement.
Experimental results regarding Li2O-ZrO2-SiO 2 (LZS) sintered glass ceramic materials obtained by extrusion of glass powders with an added inorganic material as binder, are presented. Each of the composition were char...
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Experimental results regarding Li2O-ZrO2-SiO 2 (LZS) sintered glass ceramic materials obtained by extrusion of glass powders with an added inorganic material as binder, are presented. Each of the composition were characterized by chemical analysis, laser scattering particle-size analysis, differential thermal analysis (DTA), Xray diffractometry (XRD), and thermal expansion. It was observed that after a sintering process at near by 750°C, crystallization takes place as soon as the process gets over. Once heated, the the glass powder compacts crystallize into zircon and quartz and then to lithium disilicate.
Infection by high-risk human papillomaviruses (HPVs) is associated with the development of cervical cancers. Classification of risk types is important to understand the mechanisms in infection and to develop novel ins...
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This paper focuses on implementation issues of a virtual environment to support the interaction with a Coordinate Measuring Machine (CMM), which is used to measure dimensions and form of mechanical parts. First, it gi...
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ISBN:
(纸本)0780383397
This paper focuses on implementation issues of a virtual environment to support the interaction with a Coordinate Measuring Machine (CMM), which is used to measure dimensions and form of mechanical parts. First, it gives an overview of the implementation, presenting the software "Avalon" and the basic architecture of the developed application. Then, it describes the execution environment, including the description of equipments and devices, characteristics and constraints, and system execution. Finally, it presents the conclusions of the work.
The semantic Web technology and the Web services description language extensibility may be combined to describe services in an unambiguous and machine interpretable way, automating Web services discovery, selection an...
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The semantic Web technology and the Web services description language extensibility may be combined to describe services in an unambiguous and machine interpretable way, automating Web services discovery, selection and invocation. In this paper, we present an algorithm and a prototype for the automatic composition of Web services that implement workflows described in a high level language. Our approach has many advantages comparing to the manual creation of a simple program composition, such as smaller implementation time and cost, reliability with the generation of contingency plans, greater capacity to evolve with the dynamic service discovery, and faster execution time with the use of heuristics. We use the OWLS ontology to semantically describe Web services metadata and indexes to help selecting them. The proposed algorithm considers that equivalent services may have different interfaces and also respects preferences of the users.
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