Lithographic patterning of benzoylacetone modified SnO2 and SnO2:Sb thin films

The synthesis of directly UV-photopatternable pure and antimony-doped organo-tin materials is presented. UV-photopatternability has been achieved by using the synthesized benzoylacetone modified tin and antimony 2-isopropoxyethoxides. Photopatterned pure and antimony-doped organo-tin films are crystallized by thermal annealing in order to obtain conductive SnO₂ and Sb:SnO₂ thin films. The molar ratio between benzoylacetone and metal alkoxides has to be 2 in order to obtain crack-free, good-quality structures. The effects of UV-irradiation, increasing antimony doping level and benzoylacetone concentration on the electrical properties of the single-layered films are analyzed. The highest obtained conductivity was 20 S/cm. Benzoylacetone concentration and UV-irradiation has only a negligible effect on the film electrical conductivities.     

Refractive index change in ytterbium-doped fibers induced by photodarkening and thermal bleaching

High-accuracy measurements and analysis of refractive index change induced by photodarkening and thermal bleaching in ytterbium-doped fibers are presented, based on a modal interference method. Photodarkening-induced refractive index change is positive at the ytterbium lasing wavelengths near 1080 nm, and it approaches a saturated level, which is in the order of 10(-6)～10(-5) for the tested fiber samples. It is found that the value of this refractive index change is linearly proportional to the photodarkening-induced excess loss at an arbitrary probe wavelength in the visible band. Thermal bleaching can only partially erase the photodarkening-induced refractive index change, leaving a residual index change of (0.2～0.3)×10(-5). The influence of the photodarkening-induced refractive index change on fiber lasers is discussed.     

Characterization of random rough surfaces from scattered intensities by neural networks

Abstract

Optical scatterometry, a non-invasive characterization method, is used to infer the statistical properties of random rough surfaces. The Gaussian model with rms-roughness [sgrave] and correlation length σ is considered in this paper but the employed technique is applicable to any representation of random rough surfaces. Surfaces with wide ranges of Λ and σ, up to 5 wavelengths (λ), are characterized with neural networks. Two models are used: self-organizing map (SOM) for rough classification and multi-layer perceptron (MLP) for quantitative estimation with nonlinear regression. Models infer Λ and σ from scattering, thus involving the inverse problem. The intensities are calculated with the exact electromagnetic theory, which enables a wide range of parameters. The most widely known neural network model in practise is SOM, which we use to organize samples into discrete classes with resolution ΔΛ = Δσ = 0.5λ. The more advanced MLP model is trained for optimal behaviour by providing it with known parts of input (scattering) and output (surface parameters). We show that a small amount of data is sufficient for an excellent accuracy on the order of 0.3λ and 0.15λ for estimating Λ and σ, respectively.     

Mechanosynthesis of 2,2′-((1E,1′E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-2,1-diyl))bis(6-bromoquinoline): optical,electroluminescence, electrical,electrochemical, and morphological studies

In this work is report the synthesis by mechanochemical method of a small molecule of the oligophenylene (bisquinoline) design (OBM), excellent optical and electrical properties, and potential use as an electroluminescent material in the form of a nano-film in the manufacture of an organic light-emitting diode (OLED). OBM was synthesized by a Knoevenagel condensation reaction and was chemically characterized by ¹H-NMR, ¹³C-NMR, FT-IR spectroscopy, and AccuTOF-DART mass spectrometry. UV–Vis and fluorescence spectroscopies were used to obtain the optical properties of OBM, both in solution and in film. Also, the OBM film was examined by atomic force microscopy and showed a high degree of homogeneity which allowed the manufacture of an OLED device with ITO/OBM/PEDOT: PSS/Al configuration with a luminance of 2350 cd/m² when supplied with a fixed current of 15 mA and 10 volts.

     

Serum coenzyme Q10 levels are associated with coronary flow reserve in hemodialysis patients

Accelerated atherosclerosis is the major cause of mortality in patients on chronic hemodialysis (HD). The aim of this study was to evaluate the relation between coenzyme Q10 (CoQ10) levels and coronary flow reserve (CFR) in HD patients as an indicator of atherosclerosis. Seventy‐one chronic HD patients and 65 age‐ and sex‐matched healthy individuals were included in the study. Plasma CoQ10 levels were performed by high‐performance liquid chromatography measurements. CFR was assessed by transthoracic Doppler echocardiography. Serum CoQ10 levels (1.36 ± 0.43 vs. 2.53 ± 0.55, P < 0.001) and CFR values (1.73 ± 0.11 vs. 2.32 ± 0.28, P < 0.001) were significantly lower in HD patients compared with controls. There was a significant positive correlation between CFR and serum levels of CoQ10 (r = 0.669, P < 0.001). A linear regression analysis showed that serum levels of CoQ10 were still significantly and positively correlated with CFR (regression coefficient = 0.235, P < 0.001). Our data have demonstrated that HD patients exhibit decreased plasma CoQ10 levels and CFR values. The study also showed for the first time that serum CoQ10 levels independently predict CFR in HD patients.     

Visible-light-driven photocatalysis with dopamine-derivatized titanium dioxide/<Emphasis Type="Italic">N</Emphasis>-doped carbon core/shell nanoparticles

Titanium dioxide/N-doped carbon core/shell nanoparticles enabling efficient visible-light-driven photocatalytic degradation of rhodamine B, considered a model compound for water-soluble environmental pollutants, were successfully prepared by the carbonization of dopamine-grafted TiO₂ nanoparticles. These precursor nanoparticles were prepared via simple ligand-to-metal charge transfer (LMCT) between TiO₂ nanoparticles and dopamine. Owing to the incorporation of Ti–O–C chelating bonds and the subsequent narrowing of the optical band gap, the dopamine-derivatized photocatalyst demonstrated enhanced activity compared with that of commercial photocatalysts and promoted the photocatalytic degradation of rhodamine B under both UV light and visible light. This LMCT-mediated incorporation of thin amorphous N-doped carbon shells onto the surface of semiconducting photocatalysts may be widely applicable for the generation of novel and robust hybrid materials with enhanced photocatalytic activities for many applications.     

Reliable controllable sets for constrained Markov‐Jump Linear Systems

Robust λ‐contractive sets have been proposed in previous literature for uncertain polytopic linear systems. It is well known that, if initial state is inside such sets, it is guaranteed to converge to the origin. This work presents the generalization of such concepts to systems whose behaviour changes among different linear models with probability given by a Markov chain. We propose sequence‐dependent sets and associated controllers that can ensure a reliability bound when initial conditions are outside the maximal λ‐contractive set. Such reliability bound will be understood as the probability of actually reaching the origin from a given initial condition without violating constraints. As initial conditions are further away from the origin, the likelihood of reaching the origin decreases. Copyright © 2015 John Wiley & Sons, Ltd.     

Learning from instructional animations: How does prior knowledge mediate the effect of visual cues?

The purpose of this study was to investigate the effects of cueing and prior knowledge on learning and mental effort of students studying an animation with narration. This study employed a 2 (no cueing vs. visual cueing) × 2 (low vs. high prior knowledge) between‐subjects factorial design. The results revealed a significant interaction effect between prior knowledge and cueing on learning. Low prior knowledge learners had higher scores after studying an instructional animation with visual cues, compared to those who studied the same instructional animation without visual cues. Conversely, when cues were not provided, high prior knowledge learners outperformed those high prior knowledge learners who studied with the cued version of an instructional animation. These results indicated that the effects of cueing in an instructional animation change depending on the learners' level of prior knowledge. Specifically, low prior knowledge learners benefited more when visual cues were provided, whereas cues did not facilitate learning for high prior knowledge learners.     

Silicon–glass instrumented solid-phase extraction–zone electrophoresis microchip with thin amorphous silicon film electrodes: performance in immunoaffinity analysis

Silicon–glass microchips were designed and fabricated for on-chip solid phase extraction (SPE) and zone electrophoresis studies. The solvent channels for extraction and the separation channels for analyses were fabricated sequentially on the silicon device. Electrical contacts were integrated in a fused silica glass lid. Amorphous silicon thin film electrodes were fabricated for high voltage and conductivity detection. A chip installation rack with electrical and fluidic contacts was constructed to facilitate the experiments. Simulation was used to elucidate both the liquid flow and the electric field distribution. The operational performance of the microchips was demonstrated by using a fluorescein isothiocyanate (FITC)-labelled testosterone derivative as the model analyte and fluorescein as both the negative control and the calibration compounds. In SPE an immunosorbent, based on recombinant anti-testosterone Fab-fragments, was immobilized to activated Sepharose gel. Simultaneous monitoring of the movement of FITC-testosterone from SPE cavity through the channel to the detection point was performed with a laser-induced fluorescence detector. The observed limit of detection for FITC-testosterone was 2 μM.     

Extraction of left ventricle borders with local and global priors from echocardiograms

This paper presents a novel technique for the extraction of the left ventricle borders from echocardiograms with prior information. Although the literature includes many successful prior based methods, priors that include both image and non-image related features are rare for the contour extraction. We classify these features as local and global priors where the local priors refer to the locally definable features of the target borders and global priors refer to the geometric shape properties. The local priors, which include image, motion, and local shape information, are learned with AdaBoost. The scores produced by AdaBoost for the target images are combined with the global shape prior under a level set framework. The main contributions of this paper are to learn different types of local features efficiently with machine learning and to combine these features with the geometric shape information for the contour extraction task. The system is validated on the real echocardiograms and synthetic images. The results indicate that using local and global priors together produces better extraction results and the contours extracted by the proposed system are in accord with the expert delineated borders.