Surface modification of nano-TiO2 with lanthanide-acetylacetonate complexes

The surface modification of nano-TiO2 was carried out with lanthanide-acetylacetonate complexes by adsorption method. The effects of lanthanide complexes content, lanthanide element type, adsorption temperature, solvent dosage, adsorption time and other conditions on the photodegradation activity of methyl orange by the modified catalyst were studied, and suitable modification conditions were obtained. The results show that the photocatalytic activity of the modified nano-TiO2 is much higher than that of the unmodified pure TiO2, and the lanthanide-acetylacetonate complexes is an excellent surface modifier.

An evaluation of approaches for enhancing inductive learning with a transductive view

Availability of enough labeled data is a challenge for most inductive learners who try to generalize based on limited labeled dataset. A traditional semi-supervised approach for the same problem attempts to approach it by methods such as wrapping multiple inductive learners on derived pseudo-labels, unsupervised feature extraction or suitable modification of the objective function. In this work, a simple approach is adopted whereby an inductive learner is enhanced by suitably enabling it with a transductive view of the data. The experiments, though conducted on a small dataset, successfully provide few insights i.e. transductive view benefits an inductive learner, a transductive view that considers both attribute and relations is more effective than one that considers either attributes or relations and graph convolution based embedding algorithms effectively captures the information from transductive views compared to popular knowledge embedding approaches.

Rewolucje naukowe według Sadego a dzisiejsza epistemologia

W. Sady’s book Struktura rewolucji relatywistycznej i kwantowej w fizyce [The Structure of the Relativist and Quantum Revolutions in Physics] is discussed. In his analysis of the history of physics of XIX and early XX centuries the Author argues, contrary to Kuhn, that grand discoveries result as conclusions from certain assumptions and suitably selected pieces of background knowledge. I point to major Sady’s inspirations — Wittgenstein, Wiśniewski and Fleck — and the kinship of his account to hinge epistemology and my sandwich theory of knowledge. His view on the social nature of knowledge and the role of mathematics is commented upon. In conclusion I suggest that the tension between Sady’s antirealism and traditional truth requirement for knowledge can be resolved by a suitable modification of Ajdukiewicz’s radical conventionalism.

Study of the properties of chemically resistant repair mortar with the use of secondary raw materials

This paper deals with the research of a new silicate-based repair mortar modified with selected secondary raw materials. The aim of this work is to develop a chemically resistant material suitable for use in an extremely aggressive environment of sewers. The monitored parameters include key physical-mechanical characteristics, resistance to sulphate ions and to the attack of aggressive biogenic sulfuric acid. Chemical resistance was tested by simulating the exposure environment in laboratory conditions, according to the methodology of DIN 19573. The obtained results show that by suitable modification of the reference mortar it is possible to maintain the values of physical-mechanical characteristics and improve the chemical resistance of test samples.

Co-clustering of Time-Dependent Data via the Shape Invariant Model

Multivariate time-dependent data, where multiple features are observed over time for a set of individuals, are increasingly widespread in many application domains. To model these data, we need to account for relations among both time instants and variables and, at the same time, for subject heterogeneity. We propose a new co-clustering methodology for grouping individuals and variables simultaneously, designed to handle both functional and longitudinal data. Our approach borrows some concepts from the curve registration framework by embedding the shape invariant model in the latent block model, estimated via a suitable modification of the SEM-Gibbs algorithm. The resulting procedure allows for several user-defined specifications of the notion of cluster that can be chosen on substantive grounds and provides parsimonious summaries of complex time-dependent data by partitioning data matrices into homogeneous blocks. Along with the explicit modelling of time evolution, these aspects allow for an easy interpretation of the clusters, from which also low-dimensional settings may benefit.

DETECTION OF THE PRESENCE OF MICROORGANISMS DURING PRODUCTION OF PLASTERBOARD

This article is focused on detection microorganisms appearing during production of gypsum plasterboards. The research is carried out within the project TAČR ZÉTA TJ02000235 Sádrokarton se zvýšenou odolností proti bilogické degradaci (Gypsum plasterboard with increased biodegradation resistance). This article shows first part of this issue what was detection of the most critical place of production, where is the highest risk of bacterial contamination and it open the area to find suitable modification of production process or recipes of gypsum plasterboards.

APPLICATION OF THE MORI-TANAKA METHOD TO DESCRIBE THE RATE-DEPENDENT BEHAVIOR OF UNIDIRECTIONAL FIBROUS COMPOSITES

This paper examines the possibility of using the Mori-Tanaka micromechanical model describe the rate dependent behavior of the polymer matrix based fibrous composites. The generalized Leonov model is adopted to capture the time and rate dependent character of the selected matrix, while fibers are assumed elastic. The performance of the Mori-Tanaka method is tested against the finite element simulations carried out in the framework of first-order homogenization. For simplicity, the periodichexagonal array model is chosen to represent the microstructural arrangement of fibers in the yarn cross-section. To match the predictions provided by the two approaches a suitable modification to the original Mori-Tanaka method is proposed. An extensive parametric study is presented to illustrate a considerable improvement of the predictive capability of the modified Mori-Tanaka method.

Incremental Formula-Based Fix Localization

Automatically fixing bugs in software programs can significantly reduce the cost and improve the productivity of the software. Toward this goal, a critical and challenging problem is automatic fix localization, which identifies program locations where a bug fix can be synthesized. In this paper, we present AgxFaults, a technique that automatically identifies minimal subsets of program statements at which a suitable modification can remove the error. AgxFaults works based on dynamically encoding semantic of program parts that are relevant to an observed error into an unsatisfiable logical formula and then manipulating this formula in an increasingly on-demand manner. We perform various experiments on faulty versions of the traffic collision avoidance system (TCAS) program in the Siemens Suite, programs in Bekkouche’s benchmark, and server real bugs in the Defects4J benchmark. The experimental results show that AgxFaults outperforms single-path-formula approaches in terms of effectiveness in finding fix localization and fault localization. AgxFaults is better than program-formula-based approaches in terms of efficiency and scalability, while providing similar effectiveness. Specifically, the solving time of AgxFaults is 28% faster, and the running time is 45% faster, than the program-formula-based approach, while providing similar fault localization results.

Cold Plasma: Clean Technology to Destroy Pathogenic Micro-organisms

Atmospheric pressure cold plasma is a promising technology in fighting pathogenic micro-organisms. In times of Covid-19 pandemic, we have decided to modify two types of cold plasma devices to study their effectiveness in the killing of pathogenic micro-organisms. Our studies have shown that both the devices are efficient in this purpose. While pencil like microwave based device can destroy Aeromonas bacteria and bacteriophage from 6 cm distance in 2 minutes, the larger (~ 40 cm2) RF plasma based device could do the similar killing ability for the larger possible area in 4 minutes. OES studies revealed that both these device produce OH radicals which helped in the destruction of both bacteria and bacteriophage. With suitable modification, these devices, especially the larger area device may even be implemented for the elimination of Covid-19 affected wards of hospital without using any sensitive chemical process.

Laser Micro-Texturing of Sintered Tool Materials Surface

The purpose of this paper is to show the effect of tool materials surface treatment while using laser texturing on the structure and properties of cemented carbides and sialon ceramics. The tests were made on multi-point inserts subjected laser texturization and honeycomb-like texture was obtained. Comprehensive investigations in the scanning electron microscope (SEM) were made. Morphology was examined by the use of atomic forces microscope (AFM) and confocal microscope. The chemical composition of the tested materials using energy-dispersive X-ray spectrometer (EDS) was investigated. Moreover, exploitative properties, including wear resistance using the "pin on disc" method and roughness, were also tested. It was found that the laser texturing provides a suitable modification of the structure improving tribological properties. Tests suggest that laser texturing can contribute to the durability of cutting tool’s edge, which qualifies this type of surface treatment for wide industrial applications.