2,498 research outputs found
Self-assembled metallic nanoparticle template --- a new approach of surface nanostructuring at nanometer scale
In the present work, the formation of silver and copper nanostructures on
highly oriented pyrolytic graphite (HOPG) modified with self-assembled gold
nanoparticles (Au NPs) is demonstrated. Surface patterning with nanometer
resolution was achieved. Different methods such as field emission scanning
electron microscopy (FEGSEM), energy dispersive spectrometry (EDS) and X-ray
photoelectron spectroscopy (XPS) were used to illustrate a selective deposition
of silver and copper on Au NPs. The mechanism of silver and copper ions
reduction on Au NP with -dodecanethiol coating is discussed.Comment: 6 pages, 3 figure
Policy-based autonomic control service
Recently, there has been a considerable interest in policy-based, goal-oriented service management and autonomic computing. Much work is still required to investigate designs and policy models and associate meta-reasoning systems for policy-based autonomic systems. In this paper we outline a proposed autonomic middleware control service used to orchestrate selfhealing of distributed applications. Policies are used to adjust the systems autonomy and define self-healing strategies to stabilize/correct a given system in the event of failures
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Exploring adaptation & self-adaptation in autonomic computing systems
This panel paper sets out to discuss what self-adaptation
means, and to explore the extent to which current
autonomic systems exhibit truly self-adaptive behaviour.
Many of the currently cited examples are clearly
adaptive, but debate remains as to what extent they are
simply following prescribed adaptation rules within preset
bounds, and to what extent they have the ability to
truly learn new behaviour. Is there a standard test that
can be applied to differentiate? Is adaptive behaviour
sufficient anyway? Other autonomic computing issues are
also discussed
A deliberative model for self-adaptation middleware using architectural dependency
A crucial prerequisite to externalized adaptation is an understanding of how components are interconnected, or more particularly how and why they depend on one another. Such dependencies can be used to provide an architectural model, which provides a reference point for externalized adaptation. In this paper, it is described how dependencies are used as a basis to systems' self-understanding and subsequent architectural reconfigurations. The approach is based on the combination of: instrumentation services, a dependency meta-model and a system controller. In particular, the latter uses self-healing repair rules (or conflict resolution strategies), based on extensible beliefs, desires and intention (EBDI) model, to reflect reconfiguration changes back to a target application under examination
Stochastic simulation of destruction processes in self-irradiated materials
Self-irradiation damages resulting from fission processes are common
phenomena observed in nuclear fuel containing (NFC) materials. Numerous
-decays lead to local structure transformations in NFC materials. The
damages appearing due to the impacts of heavy nuclear recoils in the subsurface
layer can cause detachments of material particles. Such a behaviour is similar
to sputtering processes observed during a bombardment of the material surface
by a flux of energetic particles. However, in the NFC material, the impacts are
initiated from the bulk. In this work we propose a two-dimensional mesoscopic
model to perform a stochastic simulation of the destruction processes occurring
in a subsurface region of NFC material. We describe the erosion of the material
surface, the evolution of its roughness and predict the detachment of the
material particles. Size distributions of the emitted particles are obtained in
this study. The simulation results of the model are in a qualitative agreement
with the size histogram of particles produced from the material containing
lava-like fuel formed during the Chernobyl nuclear power plant disaster.Comment: 11 pages, 8 figure
Why to Use Self Assembled Metallic Nanoparticles Template for Metal Electrodeposition: Metallic Nanostructures with Controlled Morphologies and Adjustable Wetting Properties
We investigated the benefits of using self assembled gold nanoparticles (Au NPs) template for metal electrodepositions. For short electrodeposition time, surface patterning was achieved and a well dense organized structure with nanometre resolution of metallic nanoparticles was prepared. For longer electrodeposition time, different morphologies were obtained. The mechanisms behind the formation of this morphology were analysed and discussed based on the influence of self-assembled Au NPs template in terms of thiol molecules diffusion and adsorption on metallic deposits. Furthermore adjustable wetting properties were obtained through the tuning of electrodeposition time.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3536
Thermodynamic Losses in a Gas Spring: Comparison of Experimental and Numerical Results
Reciprocating-piston devices can be used as high-efficiency compressors and/or expanders. With an optimal valve design and by carefully adjusting valve timing, pressure losses during intake and exhaust can be largely reduced. The main loss mechanism in reciprocating devices is then the thermal irreversibility due to the unsteady heat transfer between the compressed/expanded gas and the surrounding cylinder walls. In this paper, pressure, volume and temperature measurements in a piston-cylinder crankshaft driven gas spring are compared to numerical results. The experimental apparatus experiences mass leakage while the CFD code predicts heat transfer in an ideal closed gas spring. Comparison of experimental and numerical results allows one to better understand the loss mechanisms in play. Heat and mass losses in the experiment are decoupled and the system losses are calculated over a range of frequencies. As expected, compression and expansion approach adiabatic processes for higher frequencies, resulting in higher efficiency. The objective of this study is to observe and explain the discrepancies obtained between the computational and experimental results and to propose further steps to improve the analysis of the loss mechanisms
A Diversity-Accuracy Measure for Homogenous Ensemble Selection
Several selection methods in the literature are essentially based on an evaluation function that determines whether a model M contributes positively to boost the performances of the whole ensemble. In this paper, we propose a method called DIversity and ACcuracy for Ensemble Selection (DIACES) using an evaluation function based on both diversity and accuracy. The method is applied on homogenous ensembles composed of C4.5 decision trees and based on a hill climbing strategy. This allows selecting ensembles with the best compromise between maximum diversity and minimum error rate. Comparative studies show that in most cases the proposed method generates reduced size ensembles with better performances than usual ensemble simplification methods
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