Electrodeposition of silver from nitrate solution: Part II. Mechanism of the effect of phosphate ions

The mechanism of compact Ag-film formation by electrolysis from nitrate solution with addition of small amounts of phosphate ions is elucidated. It is shown that the phosphate ions exert their effect by lowering the exchange current density. Consequently, the radii of nucleation exclusion zones also diminishes, thus producing conditions stimulating electrodeposition of continuous thin Ag-film.     

Sequence classification via large margin hidden Markov models

We address the sequence classification problem using a probabilistic model based on hidden Markov models (HMMs). In contrast to commonly-used likelihood-based learning methods such as the joint/conditional maximum likelihood estimator, we introduce a discriminative learning algorithm that focuses on class margin maximization. Our approach has two main advantages: (i) As an extension of support vector machines (SVMs) to sequential, non-Euclidean data, the approach inherits benefits of margin-based classifiers, such as the provable generalization error bounds. (ii) Unlike many algorithms based on non-parametric estimation of similarity measures that enforce weak constraints on the data domain, our approach utilizes the HMM’s latent Markov structure to regularize the model in the high-dimensional sequence space. We demonstrate significant improvements in classification performance of the proposed method in an extensive set of evaluations on time-series sequence data that frequently appear in data mining and computer vision domains.     

Universal probability-free prediction

We construct universal prediction systems in the spirit of Popper’s falsifiability and Kolmogorov complexity and randomness. These prediction systems do not depend on any statistical assumptions (but under the IID assumption they dominate, to within the usual accuracy, conformal prediction). Our constructions give rise to a theory of algorithmic complexity and randomness of time containing analogues of several notions and results of the classical theory of Kolmogorov complexity and randomness.     

Lactobionic acid as antioxidant and moisturizing active in alkyl polyglucoside-based topical emulsions: the colloidal structure, stability and efficacy evaluation

Cosmeceutical antioxidants may protect the skin against oxidative injury, involved in the pathogenesis of many skin disorders. However, an unsuitable topical delivery system with compromising safety profile can affect the efficacy of an antioxidant active. This study investigated the antioxidant potential of lactobionic acid (LA), a newer cosmeceutical active, per se (in solution) and incorporated into natural alkyl polyglucoside (APG) emulsifier-based system using 1,1-diphenyl-2-picrylhydrazyl free radical scavenging and lipid peroxidation inhibition assays. The α-tocopherol was used as a reference compound. The physical stability (using rheology, polarization microscopy, pH and conductivity measurements) of an Alkyl glucoside-based emulsion was evaluated with and without the active (LA); colloidal structure was assessed using polarization and transmission electron microscopy, rheology, thermal and texture analysis. Additionally, the safety profile and moisturizing potential were investigated using the methods of skin bioengineering. Good physical stability and applicative characteristics were obtained although LA strongly influenced the colloidal structure of the vehicle. LA per se and in APG-based emulsion showed satisfying antioxidant activity that promotes it as mild multifunctional cosmeceutical efficient in the treatment and prevention of the photoaged skin. Employed assays were shown as suitable for the antioxidant activity evaluation of LA in APG-based emulsions, but not for α-tocopherol in the same vehicle.     

Optimized preparation of alumina based fillers for tuning composite properties

Alumina based particles were prepared from aluminium chloride hydroxide as starting material by sol-gel technique. One series of particles was doped with ferrous oxide. Both series of particles were calcinated at three different temperatures: 700?°C, 800?°C and 900?°C. Poly(methyl methacrylate), PMMA, was used as a matrix and two different types of alumina based particles were added into the matrix to form the composites. All composites consisted of 3?wt% of alumina based particles. The aim of this study was to examine whether and how the temperature of particle calcination affects the microhardness and mechanical properties of the composite. The particles were characterized by the X-ray diffraction (XRD) and physical absorption methods. The morphology of the composites was examined using a field emission scanning electron microscope (FESEM). The microhardness of composites was measured using a traditional Vickers hardness (HV) method. The mechanical characteristics of obtained composites were determined using tensile test and impact testing.     

Polarization behavior of ferroelectricBi4Ti3O12 ceramics

The effect of oxidation and reduction atmospheres on the ferroelectric behavior of bismuth titanate was investigated. The effective surface density σ_eff of free charges in samples polarized by applying an electric field E_p=1 MV m^-1 at a temperature of 100°C for 90 min was determined by compensation voltage measurements. The thermally treated samples in oxidation atmospheres exhibit a significant decrease of σ_eff while those treated in a reducing atmosphere exhibit an increase accompanied by an improvement in the stability of the electret charge. Such observations indicate that the formation as well as the transformation of the electret state of Bi₄Ti₃O ₁₂ ceramics may be related to the enhancement and diminishing of oxygen vacancies. In all cases homocharge with a time independent sign was obtained     

The effect of boron on the stereological characteristics of the structural phases present in the structure of the 13% Cr white iron

In this paper, the results of the examination of the effect of boron, in the amounts of 0.26, 0.39 and 0.59 wt%, on the stereological characteristics of the structural phases present in the structure of 13%Cr–2.3%C white iron, are reviewed. The examined stereological characteristics were: volume fraction of phases, dendrite arm spacing-DAS and size of eutectic carbides.It has been concluded that with the increasing of boron content, the volume fraction of the matrix of austenite partially transformed into martensite decreases, whereas the volume fraction of the eutectic carbides increases. The increasing of the boron content also decreases the value of DAS, but at the same time the eutectic carbides become coarser.     

From majority to minority and vice versa: The asymmetrical effects of losing and gaining majority position within a group.

Two studies examined the effects of stable, partially changed, and completely changed majority and minority positions within a group on perception and evaluation of the group. It was hypothesized that loss of majority position (majority-to-minority change) would have stronger effects than gain of majority position (minority-to-majority change). The hypothesized asymmetrical effect was demonstrated in that loss of majority position decreased perception of group—self similarity, group attraction, and expectations for positive interactions with the group, whereas a corresponding gain of position did not increase them. Thus immediately following changes, the group is especially fragile because disintegrative forces created by the loss of majority position are stronger than integrative forces created by the gain of majority position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gustatory thalamus lesions eliminate successive negative contrast in rats.

Neurologically intact rats expecting to receive a high-value reward (1.0 M sucrose), licked less for an unexpected low-value reward (0.15% saccharin) than did control subjects that only received the saccharin solution. This reward comparison effect, termed successive negative contrast, was eliminated after bilateral electrolytic lesions of the gustatory thalamus. The results are discussed in terms of disrupted memory processes that may have rendered the lesioned rats incapable of computing the relative reward value of the available solution (0. 15% saccharin) with respect to the memory of the preferred solution (1.0 M sucrose). (PsycINFO Database Record (c) 2010 APA, all rights reserved)