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.
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.
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.
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.
In this paper, we propose a Genetic Algorithm (GA) using symbiotic evolutionary viruses based on both the building block hypothesis and the virus theory of evolution. The proposed GA aims to control the destruction of...
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Interviews of twenty-six Industrial engineering students and graduates were conducted during the first year of a three year study of the unexpected attainment of gender parity in the School of Industrial engineering a...
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Interviews of twenty-six Industrial engineering students and graduates were conducted during the first year of a three year study of the unexpected attainment of gender parity in the School of Industrial engineering at the University of Oklahoma (OU). An analysis of the pattern of participant responses gives insight into industrial engineering (IE) student perceptions of IE. The perceptions were grouped into three broad themes: Career Profile, Discipline Profile, and Discipline Meta-Profile. The Career Profile includes the availability of multiple career paths and flexible careers in this discipline in addition to the potential for the attainment of status through entry into management. People-oriented, broad, and systems-oriented are terms that were used to describe the Discipline Profile. Discipline Meta-Profile is used to describe the participant's perception of other people's perceptions of industrial engineering (i.e. what IE students think other people think). These participants felt that other engineers think of IE as easy, or "imaginary" engineering. The participants also thought that the discipline is invisible, even to other engineers. While the meta-perception of IE might seem to be problematic for the discipline, many of the participants reject the meta-perception. Some participants recognized that IE's focus on people and systems is simply different than other engineering disciplines, not necessarily easier. Other participants felt the potential to enter into management outweighed the discipline meta-perception. One student summarized the response particularly well when he noted that IE is "inviteful" engineering.
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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In this paper, we start from a case study of an architecture company and move on to a framework of agents to identify and inform conceptual design. The processes and problems exhibited by the company involved are quit...
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In this study, various thicknesses of Pd catalytic films were deposited on Ti/Si substrates and pretreated with NH/sub 3/. The effects of catalyst deposition parameters and NH/sub 3/ pretreatment time (0, 1, and 10 mi...
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In this study, various thicknesses of Pd catalytic films were deposited on Ti/Si substrates and pretreated with NH/sub 3/. The effects of catalyst deposition parameters and NH/sub 3/ pretreatment time (0, 1, and 10 minutes) on the size distribution of Pd catalytic particles, and subsequently, on the diameter and density of synthesized carbon nanotubes (CNTs) were investigated. The CNTs were synthesized by thermal CVD at 750/spl deg/C using methane (CH/sub 4/) as the carbon source, and a mixture of Ar/H/sub 2/ (80 vol.%/20 vol.%) as the carrier gas.
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