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In this paper, a computational method to predict the corrosion resistance of some ironbased powder metallurgy (P/M) materials is proposed. The samples prepared from atomized iron powder and pre-alloyed iron base powders powders were the materials analyzed in this paper. The compacted samples were obtained by powder metallurgy process, respectively pressing and sintering of the mixed powders. The samples were compacted at a pressures of 400 and 600 MPa. The sintering temperature was approximately 1.150 В°C. The inf...

In all industrial branches, the last period is under the sign of economic progress, but with the lowest energy consumption and the lowest possible release of pollutants. Technologically, therefore, the removal of polluting technologies and the introduction of new "environmentally friendly" technologies are being sought. Thus, the new industrial trend is to reduce the use of molded or forged semi finished products and the introduction of cold rolled semi finished products or other processes. This transformation can...

This paper describes the design of a new product, conceived by the authors, part of a research contract and of a technological transfer, from university to the industrial market. It is a low voltage class C surge-arrester, based only on metal-oxide varistors, designed for low voltage residential equipment. Located in the indoor interior connection boxes, it could protect the whole installation against any type of occurring overvoltage (pulsed or long time one). The results of the applicative research were transfer...

The purpose of the paper is to obtain a new composite material based on chemically functionalized nanoparticles dispersed in plastomer matrix. The dispersion of the TiO2 hybrid nanoparticles (filler) in a plastomer matrix (polyvinyl chloride-PVC) leads to a high-performance polymeric material with multi-functional, antibacterial, and plastomer-specific processing properties. The materials are suitable for biomedical and food industry applications and will be tested in terms of long-term stability, and antimicrobia...

Neural network method is used to solve complex modeling problems such as classification, estimation and pattern recognition. There are two main categories of ANNs which can be applied whether in regression or classification: the supervised and the unsupervised. In supervised model, all the data is labeled and the network is learned to predict the output values from the input data as previous experimental. In unsupervised model, all the data is unlabeled and the network is learned to inherent structure from the inp...

Testing of synthesized magnetically separable catalyst (Pd-Fe3O4/HPS) was carried out in the selective hydrogenation of 2-methyl-3-butyn-2-ol to corresponding olefinic alcohol and also in the Suzuki cross-coupling of 4-bromoanisole and phenylboronic acid in a shaker-type glass batch reactor. In the case of selective hydrogenation, the use of Pd-Fe3O4/HPS was found to result in 94% selectivity at 95% of the substrate conversion that is typical for preliminarily reduced Pd/HPS catalysts. Regarding to the Suzuki reac...

Aqueous-dispersion acrylate compositions with different contents of silica nanoparticles (NP) were prepared, which allowed to obtain top transparent coatings with improved abrasion resistance. The nanoscale silica used in the work was obtained by a gas-phase method using high-frequency induction discharge (HFI) in the air atmosphere. The average size of silica nanoparticles measured by transmission electron microscopy (TEM) and laser scattering was 23.5 nm. TEM photos of silica nanoparticles showed that silica was...

In this paper, a pipeline implementing a multi-scale approach that can be used for modelling different steps of aerogel production is presented. Closely integrated modulesfor aerogel structures generation, properties prediction and adsorption, diffusion and chromatography processes modelling provide various options for systematic and comprehensive study of aerogels by performing computational experiments, which allows to reduce number of laboratory experiments. The results of pipeline validation are presented for ...

This study has its aim to compare the performance of modern structured and unstructured catalysts in a dry reforming of methane (DRM). DRM is used to obtain a mixture of H2 and CO with almost equal fractions of both products, which is subsequently used in synthesis of some chemical valuable products. The kinetic scheme for tungsten carbide (WC) catalyst was taken from the literature. Using the experimental data for a fixed bed catalyst, we have fitted the parameters of the kinetic scheme of DRM on WC catalyst. The...

Due to the increased consumption of S420NL thick steel plates, the world steel price is expected to decrease. The main purpose of this investigation is to find an optimal solution both from a technical and commercial point of view to produce heavy plate 40 mm thick microalloyed S420NL hypoeutectoid steel. The imposed resistance class for this alloy is 420MPa with proven tenacity properties at temperatures up to-50 В°C. The experiment encompasses the necessity of defining a metallurgical route including chemical co...

The use of corrosion inhibitors in the paint materials is an important task, since inhibitors often cannot be included individually in the paint formulation directly. In this case, corrosion inhibitor having a high affinity to the surface of a substrate and a plasticizing effect in relation to the film-forming base of the formed coating can have a negative impact on its adhesion and physical and mechanical properties. One of the ways to eliminate this disadvantage is the use of immobilized inhibitors, in particula...

Last years the use of sub- and supercritical fluids in the catalyst synthesis is a great attention. Because of the unique properties subcritical water allow synthesizing the metal-based catalysts with the desired size, dispersity, structure and morphology of the active phase. In this work, we report the study of the structure of polymer-based Pdcontaining catalysts synthesized by hydrothermal deposition. It is shown that the use of palladium chloride as a metal precursor decreases significantly the specific surfac...

Gallium phosphide is a semiconductor material of great interest for new LED technologies. Porous AIII?V are of great interest because of their interesting optical properties different of those for bulk material. The main goal of this research work is to obtain nanostructured porous gallium phosphide (por-GaP) layers by electrochemical etching of the monocrystalline (100) p-type GaP substrate surface. The structure and surface morphology of obtained samples were studied by scanning electron microscopy (SEM), atomic...

The goal of the work reported in this paper is to describe and develop an artificial neural network (ANN) to evaluate the effect of processing parameters such as density, pressing and sintering time on microstructural characteristics including porosity and microstructure of some iron-based powder metallurgy (PM) materials. There are various methods for generating models to predict the the effect of processing parameters. The materials used in this study are prealloyed iron-based powders. The particle size of the p...

Skin cancer is a disease with an increasing incidence due to its complex etiology and various forms of manifestation. The topical treatment can be a successful therapeutic approach in early diagnosed cutaneous neoplasm. The main drawback of the drugs currently in use is the low bioavailability caused by many pathophysiological and pharmaceutical factors. The aim of the present study was to develop new modifiedrelease topical products by encapsulating bexarotene into biocompatible silica matrices and by formulating...

Recent developments in the existing molecular genetic tools have augmented our current understanding towards the deleterious effects of nanoparticles on human health. During building construction, the rapid generation of nanoparticles has greatly affected to human with severe toxicity by generating free radicals inside their body as potential health hazards. However, there is still need of analyzing nanoparticle toxicity based on the type of microbial diversity present on surface and its potential impacts on human...

In the present study, an image porcessing analysis of porosity in some iron-based powder materials was proposed. The specimens analyzed were produced from atomised iron powders of different sizes (< 45, 45-63, 63-100, 100-150, >150 ?m). The analyzed powders were compressed in a mold using uniaxial pressing and the applied pressure was 600 MPa with the disc dimensions of ? 8 ? 6 mm. The compacts were sintered at a temperature of 1.150 В°C with the sintering time of 60 and 90 minutes. The sintered specimens obtained...

The research consisted in obtaining Ni-P and Ni-P-Al2O3 coatings followed by heat treatment and characterization of heat treated and untreated layers. The layers were deposited on the steel strip, by electroless method to certain process parameters. To obtain the Ni-P-Al2O3 nanocomposite layers, 5 g/L Al2O3 particles of 20 nm were introduced into the nickel bath, and it has been worked with the same parameters as to obtain the Ni-P layer. The samples were heat treated at 300 0C, 400 0C and 5000C for one hour in a ...

The structure and the properties of the oxide nano-composition coatings formed on titanium in the diphosphate based electrolytes by means of plasma electrolytic oxidation in the spark-discharge regime at application of interelectrode voltage 100 to 130 V have been studied. The possibility to obtain the oxide layers containing the alloying elements by the modification of the composition of electrolytes has been stated. The chemical and phase composition as well as the topography, the microstructure and the grain si...

This paper presents studies on the development of nanocomposites based on rubber and layered nanoclay such as organically modified montmorillonite. The effect of introducing nanoclay in a mixture based on ethylene-propylene-diene terpolymers filled with precipitated silica was analzyed in comparison with a mixture based on natural rubber filled with an organic filler, starch. Mixtures contain 0, 3 and 6 parts nanoclay respectively to 100 rubber parts. Mixtures were obtained in a Brabender mixer. Curing agents: di(...

A technical progress in various fields of the national economy is accompanied by escalating aggression of the environment that complicates the protection of different objects made from steel, which is the main modern constructional material. Because of the corrosion attack, 50 million tons of metal is oxidized and lost almost forever every year for a mankind. In industrialized countries, annually average losses from corrosion equal to 3 - 5% from the gross domestic product. The damage from corrosion comprises not ...

Metal Oxide based Varistors are basically ceramics, acting as n ? semiconductors, having a poly-crystalline and dense structure. The main application of these power electronic devices is for construction of overvoltage protection equipment (for every voltage level), because of some advantages like: an increased level of non-linearity between the current and the voltage characteristic, a high energy adsorption capacity and an excellent good response time, which make them ideal for protecting other sensible electron...

The necessity of fulfilling as many conditions as possible in the specification resulted in the creation of composite materials. This idea developed in the aerospace industry was later used successfully in all industrial branches. The two materials that have been used are chemically distinct, each of which retains its properties in the composite, but provides the assembly with different properties and characteristics. Thus, for the continuous phase, the matrix was used an aluminum alloy, and for the discontinuous ...

Implementation of the development program for the Northern and Arctic territories is not possible without the use of modern materials and technologies in the construction industry. One of the most common and popular building materials is the fine grained concrete, for the production of which, use chemical additives, mainly imported, improving the performance characteristics of the composite. Therefore, the actual problem is the replacement of imported components with Russian-made additives. As such an additive, te...

The structure and phase composition of annealed and irradiated beryllium plates were studied by X-ray analysis. Durable X-ray irradiation leads to phase transition of a normal hexagonal beryllium lattice into a beryllium superlattice. This superlattice is composed of beryllium superatoms that form a face-centered cubic lattice with the lattice parameter of 6.2205 ? and a superatom core that crystalizes into a diamond-type lattice with the lattice parameter of 1.5703?. It is shown that beryllium has three phase sta...

At the present time, the widespread introduction of cost-effective production of a method for processing pressure in the solid phase of polymeric materials is hampered by the fact that despite the possibility of improving the strength and a number of technological characteristics of materials, high residual orientational stresses are created in the products, which over time (or when heated), lead to a change in the geometric shape and dimensions of the product. In this connection, it is promising to use the stage ...

The unique properties of aerogels make them promising materials for use in various industries. The production lines, which are currently organized by foreign companies, are aimed at obtaining exclusively monoliths and blankets of aerogels of certain sizes. However, for many potential applications, forms other than monoliths, namely particles, are required. In many works, the prospects and relevance of the use of organic aerogel particles for pharmaceuticals (drug delivery systems), medicine (medical products), foo...

Due to its properties, lightweight, strength and corrosion resistance aluminum and its alloys are chosen for building various industrial equipments that are used in different specific environments. Aluminum and its alloys cannot escape from corrosion and it requires a proper handling. Aluminum and its alloys will corrode very quickly after cleaning so any treatment must be swift to prevent corrosion becoming trapped under the base coating layers. Aluminum corrodes almost immediately forming an oxide layer that wil...

Bisphenol A (C15H16O2) 2,2-(4,4?-dihydroxydiphenyl) propane (BPA) is known for its endocrine disrupting properties in human body in addition to various other harmful effects. BPA has been detected in the aquatic environment at concentration levels varying from nanograms to micrograms per litre of water in many countries and regions. Due to the inefficiency of BPA removal using the common water treatment methods (physicochemical, biological, and electrochemical), advanced oxidation process was applied. UV-VIS photo...