Constrained Sintering of Alumina Thin Films: Comparison Between Experiment and Modeling

Alumina thin films deposited by dip coating on alumina substrates were sintered between 1150° and 1350°C. A new measuring system using a rocking arm as a mechanical amplifier allows in situ measurement of the shrinkage of the film. Comparison of experimental densification behavior with the predictions of the isotropic continuum mechanics model (using values of constitutive parameters determined by sinter forging) highlights the inadequacy of the isotropic models. These results, together with other published evidence, provide justification to consider anisotropic models.     

ASSL: A Software Engineering Approach to Autonomic Computing

ASSL provides a framework for formal specification, validation, and code generation of autonomic systems.     

Optimization and Multihazard Structural Design

There is a growing interest in the development of procedures for the design of structures exposed to multiple hazards. The goal is to achieve safer and/or more economical designs than would be the case if the structures were analyzed independently for each hazard and an envelope of the demands induced by each of the hazards were used for member sizing. We describe an optimization approach to multihazard design that achieves the greatest possible economy while satisfying specified safety-related and other constraints. We then present an application to illustrate our approach.     

Impulse plasma deposition of magnetic nanocomposite layers

The most characteristic feature of the IPD method is that the synthesis proceeds in the impulse plasma itself, with the participation of ions. The IPD growth mechanism, originating from clusters of constituent materials, makes this method particularly suitable for the fabrication of nanocomposite layers.The material synthesised in the present experiment was an Fe-Ti alloy. The sources of Fe and Ti were the internal electrodes of two independent impulse plasma accelerators operated in an alternate mode. It appeared that the Fe-Ti alloy forms at the interface between the Fe and Ti nanocrystals as a result of the surface diffusion due to the coalescence of the nanocrystals.     

Synthesis of polyurethane cationomers with anil groups: intramolecular proton transfer in salicylideneanil structures

Three new o‐hydroxy Schiff bases, 2‐chloromethyl‐N‐(2‐hydroxybenzilidene)aniline, 3‐(11‐bromoundecanoyloxymethyl)‐N‐(2‐hydroxybenzilidene)aniline and 4‐chloromethylphenyl (carbamoyloxymethyl‐2‐hydroxybenzylidene)aniline, used as quaternization agents for a polyetherurethane precursor based on poly(tetramethylene oxide) diol of 2000 g mol^?1 average molar mass (PTMO), 2,4‐toluene diisocyanate and N‐methyldiethanolamine (1:3:2 molar ratio), have been synthesized in order to obtain polymeric films with fluorescent properties. The structure and the photochromic mechanism of the salicylideneanil units were investigated. The excited state intramolecular proton‐transfer process (ESIPT) with the cis‐ and trans‐keto isomers formation as intermediate compounds and the formation of a keto tautomer were evidenced by a large Stokes shifted emission (100 nm). Copyright © 2005 Society of Chemical Industry     

The Hordaland Homocysteine Studies

The Hordaland Homocysteine Study is a population-based screening of total plasma homocysteine (tHcy) in ～18,000 men and women aged 40–67 yr that took place in 1992–1993 in the county of Hordaland in Western Norway. In this cohort, tHcy was associated with several physiologic and life-style factors, including age and gender, blood pressure, serum cholesterol, smoking, alcohol and coffe consumption, physical activity, diet, and vitamin status. All associations with established cardiovascular risk factors were in the direction expected to confer increased risk. In a subset of 5,883 women aged 40–42 yr, tHcy was associated with previous pregnancy outcomes, including preeclampsia, placental abruption, and neural tube defects. This article reviews the published results from the Hordaland Homocysteine Study in the light of relevant literature. The Hordaland Homocysteine cohort will be used for future investigations of the stability of tHcy and vitamin status over time, and to investigate associations with mortality and morbidity including cancer incidence.     

Parameters for Utilitarian Desires in a Qualitative Decision Theory

In qualitative decision-theoretic planning, desires—qualitative abstractions of utility functions—are combined with defaults—qualitative abstractions of probability distributions—to calculate the expected utilities of actions. This paper is inspired from Lang's framework of qualitative decision theory, in which utility functions are constructed from desires. Unfortunately, there is no consensus about the desirable logical properties of desires, in contrast to the case for defaults. To do justice to the wide variety of desires we define parameterized desires in an extension of Lang's framework. We introduce three parameters, which help us to implement different facets of risk. The strength parameter encodes the importance of the desire, the lifting parameter encodes how to determine the utility of a set (proposition) from the utilities of its elements (worlds), and the polarity parameter encodes the relation between gain of utility for rewards and loss of utility for violations. The parameters influence how desires interact, and they thus increase the control on the construction process of utility functions from desires.     

The Influence of UV Irradiation on Ketonic Defect Emission in Fluorene‐Based Copolymers

The influence of UV irradiation in inert atmosphere on the emission spectrum of fluorenone containing poly[9,9‐bis(2‐ethyl)hexylfluorene] (PF2/6) has been investigated by means of optical absorption, photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy. It is shown that a substantial reduction of green emission arising from ketonic defect sites can be achieved by irradiation of thin films with UV light. This is found to be accompanied by partial cross‐linking of the films. FTIR measurements show no reduction of the C=O stretching mode upon irradiation, and, moreover, the degree of cross‐linking does not scale with the relative fluorenone content (0.1, 0.5, and 5%). Therefore, the reduced emission intensity in the green spectral region is rather associated with the occurrence of interruptions in the polymer backbone, which reduce the effective conjugation length and subsequently inhibit the energy transfer onto the ketonic defect sites. The found results enabled us to build organic light emitting devices (OLEDs) that can be structured by selective illumination of the emitting layer with an intense UV light source. This method allows for the fabrication of rather efficient (2000 cd m⁻² at 7 V) two‐color OLEDs.     

Enhanced conductance fluctuation by quantum confinement effect in graphene nanoribbons

Conductance fluctuation is usually unavoidable in graphene nanoribbons (GNR) due to the presence of disorder along its edges. By measuring the low-frequency noise in GNR devices, we find that the conductance fluctuation is strongly correlated with the density-of-states of GNR. In single-layer GNR, the gate-dependence of noise shows peaks whose positions quantitatively match the subband positions in the band structures of GNR. This correlation provides a robust mechanism to electrically probe the band structure of GNR, especially when the subband structures are smeared out in conductance measurement.