3,660 research outputs found
Atomic layer deposited protective layers
This paper reviews the use of Atomic Layer Deposition (ALD) in protective coatings. Because of the growth principle ALD allows the deposition of dense conformal films on substrates of different size and shape. Recently, ALD has received increasingly interest in deposition of protective coatings. In protective coatings oxides are the most common materials and especially Al, Ti, and Ta oxides have been applied. The use of nanolaminates enables improving the protection properties. Since ALD films are pinhole-free and often thin they are used to protect against moisture, radiation, out-gassing but not often against corrosion of metals. Very good moisture barriers are obtained with thin ALD oxide layers on polymers and cardboard. This property is also very attractive in encapsulation of OLEDs. In studies of energy technology materials protection of electrodes in Li-ion batteries, fuel cells and supercapacitors by ALD has been reported and significant improvement in the stability has been achieved. Yet another area is protection of silver jewelry from tarnishing by a thin oxide layer. In traditional corrosion protection of metals ALD films have proven to be useful in tailoring of interfaces and sealing of defects in coatings made by other techniques. © 2017 Trans Tech Publications, Switzerland.Peer reviewe
Heavy Quark Parameters and Vcb from Spectral Moments in Semileptonic B Decays
We extract the heavy quark masses and non-perturbative parameters from the
Delphi preliminary measurements of the first three moments of the charged
lepton energy and hadronic mass distributions in semileptonic B decays, using a
multi-parameter fit. We adopt two formalisms, one of which does not rely on a
1/mc expansion and makes use of running quark masses. The data are consistent
and the level of accuracy of the experimental inputs largely determines the
present sensitivity. The results allow to improve on the uncertainty in the
extraction of Vcb.Comment: 13 pages, 2 figure
EuroSpine Task Force on Research: support for spine researchers
In recognition of the value of research to the practice of spine care, Federico Balagué and Ferran Pellisé, at the time President and Secretary for EuroSpine, asked Margareta Nordin to set up a Task Force on Research (TFR) for EuroSpine during summer 2011. The concept was to stimulate and facilitate a research community within the society, through two main functions: (1) distribution of EuroSpine funds to researchers; (2) develop and deliver research training/education courses. What has the EuroSpine TFR accomplished since its inception
Performance evaluation of Fractal component based systems
International audienceComponent based system development is now a well accepted design approach in software engineering. Numerous component models have been proposed and for most of them, specific software tools allow building Component Based System (CBS). Although these tools perform several checks on the built system, few of them provide formal verification of behavioural properties nor performance evaluation of the resulting system. In this context, we have developed a general method associating to a CBS, a formal model, based on Stochastic Well formed Nets, a class of high level Petri Nets, allowing qualitative behavioural analysis together with performance evaluation of this CBS. The definition of the model heavily depends on the (run time) component model used to describe the CBS. In this paper, we instantiate our method to Fractal CBS and its reference Java implementation Julia. The method starts from the Fractal architectural description of a system, and defines rules to systematically generate elements models of the CBS and their interactions. We then apply a structured method both for qualitative and performance analysis taking into account the given implementation of the Fractal model. The main interest of our method is to take advantage of the compositional definition of such systems to carry out an efficient analysis. The paper concentrates on performance evaluation and presents our method step by step with an illustrative example
Structured Performance Analysis for Component Based Systems
International audienceThe Component Based System (CBS) paradigm is now largely used to design software systems. In addition, performance and behavioural analysis remains a required step for the design and the construction of efficient systems. This is especially the case of CBS, which involve interconnected components running concurrent processes. % This paper proposes a compositional method for modeling and structured performance analysis of CBS. Modeling is based on Stochastic Well-formed Nets (SWN), a high level model of Stochastic Petri nets, widely used for dependability analysis of concurrent systems. Starting from the definition of the system given in a suitable Architecture Description Language, and from the definition of the elementary components, we build an SWN of the global system together with a set of SWNs modeling the components of the CBS and their connections. From these models, we derive performances of the system thanks to a structured analysis induced by the structure of the CBS. We describe the application of our method through an example designed in the framework of the CORBA Component Model
A Study of depletion of fragmentation particles at small angles in b-jets with the DELPHI detector at LEP
Numerical Investigations of Oscillons in 2 Dimensions
Oscillons, extremely long-living localized oscillations of a scalar field,
are studied in theories with quartic and sine-Gordon potentials in two spatial
dimensions. We present qualitative results concentrating largely on a study in
frequency space via Fourier analysis of oscillations. Oscillations take place
at a fundamental frequency just below the threshold for the production of
radiation, with exponentially suppressed harmonics. The time evolution of the
oscillation frequency points indirectly to a life time of at least 10 million
oscillations. We study also elliptical perturbations of the oscillon, which are
shown to decay. We finish by presenting results for boosted and collided
oscillons, which point to a surprising persistence and soliton-like behaviour.Comment: Matches the published version (12 pages, 34 figures
The Impact of Using Electronic Brainstorming Strategy in a Blended Learning Environment on Grade-Eleven Female Students’ Achievement in Islamic Education in the Sultanate of Oman
This study aimed at identifying the impact of using Electronic Brainstorming Strategy in a Blended Learning Environment on grade-eleven female students’ achievement in Islamic Education in the Sultanate of Oman. The study used the quasi experimental design, which consists of two experimental groups and a control group. In term of the treatment, the experimental groups were divided into two parts: The first experimental group n=30; which was taught using Electronic Brainstorming Strategy 70% electronic-30% traditional method) while the second experimental group n=30 was taught using the same strategies. The control group n=30 was taught using a traditional method. To achieve the objectives of the study, a 30-question achievement test was prepared. The test was given to a jury panel to judge its validity. As for the reliability factor, it was 0.71 as measured by Cronbach’s alpha. The results of the study showed that there were statistically significant differences between the means of the students in the three groups on the post- achievement, in favor of the first experimental group. In addition, it was found that there was a statistically significant difference in the means of the post achievement due to the method of teaching the Electronic Brainstorming Strategy and achievement levels in the favor of the first experimental group and the higher achievement level. The study recommended using the strategy of electronic brainstorming in teaching Islamic education due to its positive implications on achievement
Quantitative controls on the regional geometries and heterogeneities of the Rayda to Shu'aiba formations (Northern Oman) using forward stratigraphic modelling
The complex geometry of carbonate systems is influenced by a multitude of physical as well as biological processes. The Lower Cretaceous carbonates of Northern Oman are characterised by a variability of regional-scale geometries with expected vertical and lateral facies variations. The main environmental and tectonic controls acting on the depositional processes of the Lower Cretaceous ramps and platforms through space and geological time (in 4 dimensions) are only partially understood. In this study, we use a 4D DionisosFlow Forward Stratigraphic Modelling (FSM) approach to explore the role of: (i) eustasy; (ii) subsidence; (iii) initial paleobathymetry, and (iv) wave energy, to generate carbonate stacking patterns and heterogeneities. Carbonate production was maintained constant through deposition. Multi-disciplinary and multi-scale datasets were used (i.e. seismic, well and field data) to constrain the FSM input parameters and sensitivity analysis was carried out to validate or refute some depositional model hypotheses. Results show that basement topography and eustasy have the greatest influence on the progradational geometries and the lateral continuity of clinoform architectures during the Tithonian to Valanginian second-order super-sequence. In the Valanginian to Aptian super-sequence, subsidence was the primary control for the observed aggradational stacking pattern. Lateral and vertical stacking of carbonate lithologies, textures as well as facies are thus apprehended through this FSM approach, leading to a better assessment of petroleum systems elements as reservoir, seal and trap
Investigation of low-speed lateral control and hinge-moment characteristics of a 20-percent-chord plain aileron on a 47.7 degrees sweptback wing of aspect ratio 5.1 at a Reynolds number of 6.0 x 10(exp 6)
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