Printed electronic switch on flexible substrates using printed microcapsules

Printed electronics, the manufacturing of electronic components on large, flexible, and low-cost substrates by printing techniques, can facilitate widespread, very low-cost electronics for consumer applications and disposable devices. New technologies are needed to create functional components in this field. This paper introduces a new method to create an all-additive printed switch on flexible substrate materials, such as polymer foils and paper substrates. The active layer of the switch component consists of neutral polyaniline (PANI), which can be doped by acid to induce a shift from a non-conductive to a conductive oxidation state. Monodisperse core–shell microcapsules containing an acidic aqueous core liquid were produced by a novel inkjet-based encapsulation technology. It was shown that unfavorable water evaporation from the microcapsules could be reduced by the addition of calcium chloride to the core liquid. A switch component was prepared, consisting of inkjet-printed interdigitated silver electrodes, PANI active layer and printed microcapsules. If an external pressure was applied, for instance with a finger, then the switch component changed its state from non-conductive to conductive with a simultaneous distinct color change. The results clearly demonstrate the feasibility of the presented approach to create either a visual or electronic signal for use in printed electronic applications.     

Mutagenicity of kaempferol in V79 cells: the role of cytochromes P450

The flavonol kaempferol is widely found in the diet and is directly mutagenic in some short-term tests, such as the induction of chromosomal aberrations in eukaryotic cells. The presence of exogenous metabolizing systems enhances its mutagenicity. We have evaluated the role of cytochromes P450 in the induction of chromosomal aberrations by kaempferol in V79 cells. The results obtained suggest that there is a time-dependent biotransformation of kaempferol to quercetin, by cytochromes P450, as assessed by high pressure liquid chromatography. Quercetin seems to contribute to the mutagenicity of kaempferol in the presence of microsomal metabolizing systems. On the other hand, the direct induction of chromosomal aberrations by kaempferol does not seem to depend on the production of reactive oxygen species.     

Numerical stabilization of Biot's consolidation model by a perturbation on the flow equation

In this paper a stabilized finite element scheme for the poroelasticity equations is proposed. This method, based on the perturbation of the flow equation, allows us to use continuous piecewise linear approximation spaces for both displacements and pressure, obtaining solutions without oscillations independently of the chosen discretization parameters. The perturbation term depends on a parameter which is established in terms of the mesh size and the properties of the material. In the one‐dimensional case, this parameter is shown to be optimal. Some numerical experiments are presented indicating the efficiency of the proposed stabilization technique. Copyright © 2008 John Wiley & Sons, Ltd.     

Sous-produits industriels comme granulats routiers

Relation between the characteristics of the aggregates and the properties of some materials—Experimental research works (laboratory or site). Industrial by-products used are as follows:

- as an aggregate:

? stone and gravel pit refuse

? crushed blast furnace slag

? incenerator waste slag

- as a binder:

? hydraulic and non-hydraulic fly ash

? granulated blast furnace slag

? hydrated and carbide lime refuse.

Pavement layers applied are as follows:

- unbound base courses: mechanical stabilisation using stone pit refuse, crushed blast furnace slag, waste incinerator slag

- with hydraulic binder: (cement, fly-ash, granulated slag):

? lean concrete with crushed blast furnace slag and stone pit refuse

? hydraulically bound crushed blast furnace slag, waste incinerator slag, and sand obtained as refuse at sieving

- with hydrocarbon binder:

? bituminous stone pit refuse, bituminous crushed blast furnace slag, and bituminous mixture of gravel and sand and waste incinerator slag

? rolled asphalt with crushed blast furnace slag.

     

SOLAR GRAIN DRYING IN HUMID AND HOT-TEMPERATE CLIMATES

A natural solar drying system has been tested with wheat. Simple solar collectors give the small temperature rise needed for low temperature drying. The system, with a capacity of 35 tomes, is placed in a region of humid hot-temperate climate. It has been designed to dry all the locally produced grain (wheat, corn, soybean, sunflower, sorghum, etc.), without a supplemental heat source.

Two different types of solar collectors of the same effective area were tested, with one a storage-collector and the other a bare plate collector

Data from four field tests performed between 1981 and 1983 are given and discussed. The mean mass of water removed from the wheat per hour was of 6.54 kg, under an average air flow of 4.3 m3 /min. tonne     

Investigating the state-of-the-art in whole-body MR-based attenuation correction: an intra-individual,inter-system,inventory study on three clinical PET/MR systems

Objective

We assess inter- and intra-subject variability of magnetic resonance (MR)-based attenuation maps (MRμMaps) of human subjects for state-of-the-art positron emission tomography (PET)/MR imaging systems.

Materials and methods

Four healthy male subjects underwent repeated MR imaging with a Siemens Biograph mMR, Philips Ingenuity TF and GE SIGNA PET/MR system using product-specific MR sequences and image processing algorithms for generating MRμMaps. Total lung volumes and mean attenuation values in nine thoracic reference regions were calculated. Linear regression was used for comparing lung volumes on MRμMaps. Intra- and inter-system variability was investigated using a mixed effects model.

Results

Intra-system variability was seen for the lung volume of some subjects, (p = 0.29). Mean attenuation values across subjects were significantly different (p < 0.001) due to different segmentations of the trachea. Differences in the attenuation values caused noticeable intra-individual and inter-system differences that translated into a subsequent bias of the corrected PET activity values, as verified by independent simulations.

Conclusion

Significant differences of MRμMaps generated for the same subjects but different PET/MR systems resulted in differences in attenuation correction factors, particularly in the thorax. These differences currently limit the quantitative use of PET/MR in multi-center imaging studies.

     

Characterization of solution processed,p-doped films using hole-only devices and organic field-effect transistors

We report a solution processed, p-doped film consisting of the organic materials 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA) as the electron donor and 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) as the electron acceptor. UV–vis–NIR absorption spectra identified the presence of a charge transfer complex between the donor and acceptor in the doped films. Field-effect transistors were used to characterize charge transport properties of the films, yielding mobility values. Upon doping, mobility increased and then slightly decreased while carrier concentration increased by two orders of magnitude, which in tandem leads to conductivity increasing from 4 × 10^?10 S/cm when undoped to 2 × 10^?7 S/cm at 30 mol% F3TCNQ-Adl. The hole density was calculated based on mobility values extracted from OFET data and conductivity values extracted from bulk I–V data for the MTDATA: x mol% F3TCNQ-Sdl films. These films were then shown to function as the hole injection/hole transport layer in a phosphorescent blue OLED.     

Incongruence between the cps type 2 genotype and host-related phenotypes of an Enterococcus faecalis food isolate

Enterococcus faecalis is a nosocomial opportunistic pathogen, but is also found in fermented food products where it plays a fundamental role in the fermentation process. Previously, we have described the non-starter E. faecalis cheese isolate QA29b as harboring virulence genes and proven to be virulent in Galleria mellonella virulence model. In this study, we further characterized this food strain concerning traits relevant for the host-pathogen relationship. QA29b was found to belong to sequence type (ST) 72, a common ST among food isolates, and thus we consider it as a good representative of food E. faecalis strains. It demonstrated high ability to form biofilms, to adhere to epithelial cells and was readily eliminated by J774.A1 macrophage cells. Despite carrying the cps locus associated with the capsular polysaccharide CPS 2 type, cps genes were not expressed, likely due to an IS6770 inserted in the cpsC-cpsK promoter region. This work constitutes the first study of traits important for interaction, colonization and infection in the host performed on a good representative of E. faecalis food isolates. Reported results stress the need for a reliable serotyping assay of E. faecalis, as cps genotyping may not be reliable. Overall, QA29b characterization shows that despite its virulence potential in an insect model, this food strain is readily eliminated by mammalian macrophages. Thus, fine tuned approaches combining cellular and mammalian models are needed to address and elucidate the multifactorial aspect of virulence potential associated with food isolates.     

Evaluation of glue line shear strength of laminated timber structures using block and core type specimens

Monitoring and evaluation of glued laminated timber structures in service is essential to warrant its integrity, where non-destructive techniques play an important role. This paper describes the results obtained on glued laminated timber beams of maritime pine, with and without preservative treatment, and of spruce, exposed to natural outdoor environment as well as to artificial weathering. The assessment of glue lines’ shear strength was investigated through the extraction and testing of cores parallel and perpendicular to the glued lines and block shear specimens with 50 mm?×?50 mm and 20 mm?×?20 mm shear area. The results highlight the different performances of the various types of specimens tested, showing that the measured shear strength depends on the specimen size and that the size effect depends on the material strength giving a decreasing modification factor with the increase of strength in opposition to the constant factor suggested by standard EN 14080. They also show that shear testing of cores drilled perpendicular to the glued joints may be a promising tool in the assessment of glulam structures on site.