Molecular dynamics simulations are performed on parallel computers to investigate the crystalline Si(111)∕Si3N4(0001) interface that is modeled as an eight-component system. The average total energy per particle and ...
Molecular dynamics simulations are performed on parallel computers to investigate the crystalline Si(111)∕Si3N4(0001) interface that is modeled as an eight-component system. The average total energy per particle and the average kinetic energy per particle of the subsystems are monitored during the preparation of the system. The Young’s modulus of the interface is compared with that of the silicon part alone and that of the silicon-nitride film, respectively. The results for one extended simulation feature a crack in the silicon-nitride film and dislocated atoms in silicon below the crack. Simulations at rates of strain ranging from 0.00125to0.05ps−1 show that for lower strain rates, the systems stretched faster reach their ultimate strength at a higher strain value than those that were stretched more slowly. At the highest strain rates, however, the failure mechanisms change qualitatively indicative of a more ductile behavior.
Carbon nanotubes (CNTs) are hollow cylinders composed of one or more concentric layers of carbon atoms arranged in a honeycomb lattice. CNTs are widely considered as an elemental material for a future nanoelectronic t...
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ISBN:
(纸本)1557527970
Carbon nanotubes (CNTs) are hollow cylinders composed of one or more concentric layers of carbon atoms arranged in a honeycomb lattice. CNTs are widely considered as an elemental material for a future nanoelectronic technology. This is not simply due to their small size but rather to their overall properties: CNTs are known to exhibit either metallic or semiconducting behaviour, with the band gap being dependent on the nanotube diameter. Both active devices (transistors) and interconnects can be made out of semiconducting and metallic nanotubes, respectively. The key nanotube dimension, their diameter, is controlled by chemistry, not conventional fabrication. The strong covalent bonding gives the CNTs high mechanical and thermal stability and ability to sustain current densities as high as 10 A/cm2.
This work is about the use of a microcomputer network as a parallel processing environment. In order to allow the communication, the synchronization and the distribution of the tasks among processes, the PVM (Parallel...
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Blackouts are becoming an increasingly common phenomenon in this present day deregulatory environment faced by the power industry. Early detection and prevention of blackouts still remain an unsolved problem to the ex...
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Blackouts are becoming an increasingly common phenomenon in this present day deregulatory environment faced by the power industry. Early detection and prevention of blackouts still remain an unsolved problem to the experts in this area, even with all the advancements in the fields of power system reliability, security and communication technologies. Although blackouts may be initiated by a simple technical malfunction or a vegetation problem, their ultimate impact is so large that it might even hamper a country's socio-economic situation. The August 2003 Blackout in NE United States and the above mentioned reasons have motivated this overview study to catalog the extent, causes and suggested remedies of some of the major blackouts around the world. The possible role of distributed generation to mitigate the impacts of large blackouts is briefly discussed.
This paper presents the stochastic model for the operation of an on-site bottoming-cycle cogeneration acuity operating under the energy spot prices and in parallel with an electricity provider. Thus, it makes possible...
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This paper presents the stochastic model for the operation of an on-site bottoming-cycle cogeneration acuity operating under the energy spot prices and in parallel with an electricity provider. Thus, it makes possible to purchase needed electric energy or sell any excess in each time-band. The model assumes the modified Gaussian distribution for loads and binomial distribution for the on-site cogeneration facility.
In this paper, we discuss the joint time-frequency properties of a transient freak wave in order to distinguish the freak wave from non-freak waves in a quantitative manner. Exploring the use of an alternative to wave...
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Utilization of daylight is one of the most cost-effective energy-conserving strategies in the design and engineering of energy-efficient buildings. Integration between daylight and electric lighting systems in commerc...
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Utilization of daylight is one of the most cost-effective energy-conserving strategies in the design and engineering of energy-efficient buildings. Integration between daylight and electric lighting systems in commercial buildings results in a significant reduction in annual energy use and operating cost In conjunction with the School of Architecture we are working on the construction of an artificial sky laboratory so that students can study the effects of various sky conditions on interior illumination levels in buildings due to ambient daylight The array dimmer will control hundreds of light sources. LABVIEW, a National Instruments software product, will be used to develop a user-friendly interface. The design architecture of the array dimmer using micro-controllers and its connection to a PC with a user-friendly LABVIEW interface will be discussed. The user interface will allow the user to load preexisting luminosity data files from the PC, which would then command the array dimmer to duplicate those conditions.
We investigate the issues in voice communications over tandem heterogeneous network connections which require multiple source decoding/encoding operations. While it is known from speech coding research that tandem con...
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ISBN:
(纸本)0780383796
We investigate the issues in voice communications over tandem heterogeneous network connections which require multiple source decoding/encoding operations. While it is known from speech coding research that tandem connections of different speech coders can extract a substantial performance penalty, it is shown that the use of error concealment and source re-encoding can improve system performance in the presence of channel impairments such as bit errors and packet losses. A new protocol is proposed for wireless LANs that reduces retransmissions and discarded packets, and hence reduces system delay and facilitates packet loss concealment.
Distributed generation (DG) is being connected to distribution systems throughout the U.S. and the world. This is occurring even though there are deployment questions that make eventual DG penetration levels uncertain...
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Distributed generation (DG) is being connected to distribution systems throughout the U.S. and the world. This is occurring even though there are deployment questions that make eventual DG penetration levels uncertain. In act. some of the initial enthusiasm for DG may have faded over the past few years due in part to these unanswered questions. Even so, utilities should plan for DG technologies, evaluating their potential system affects and benefits both technically and economically This paper summarizes the present state of DG through a review of published literature on the subject. It identifies issues that should be considered by a distribution utility in connecting DG to the grid today and in planning for the future. It also presents a number of significant issues regarding DG that have not been sufficiently addressed. These issues are very important for utilities, and must be addressed before widespread use of DG will be feasible, and before the economic risk for most investors will be acceptable.
The integration of Distribution Energy Resources (DER) into electric power systems is critically dependent on ownership alternatives, control, operation and event-management The seamless integration of DER requires a ...
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The integration of Distribution Energy Resources (DER) into electric power systems is critically dependent on ownership alternatives, control, operation and event-management The seamless integration of DER requires a reliable communication interface that is compatible "System-wide" with current and emerging technologies. However, with DER finding a wide range of applications and benefits ranging from reciprocating engines used for peak shaving applications to Inverter-connected Wind turbines with Ultracapacitor storage for smoothing short-term power fluctuations, the requirements of communication mechanisms sharpened to adapt to DER situations is gaining importance. The characteristics of the communication mechanisms for DER seem to be site and equipment specific and generically non-deterministic. Additionally, utilities and Electric power cooperatives are keen to adopt a strategic DER communication and control architecture that is compatible and scalable with tite legacy architectures like DNP, SCADA and Modbus in addition to be compliant-enabled for existing or promulgated DER communication standards.
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