Laser welding with filler material in the form of a wire

The methods for synthesis of arc surfacing using holding, displacing, vibroarc and cutting effects are developed. The concept of waste-free machining by cutting and a number of technological measures (flexible alloying and nano-reinforcement, multi-electrode processes, directional cooling), expanding the technological possibilities of surfacing, is described.     

Single-layer bronze hardfacing with the TIG method

This article presents an assessment of TIG pad welding technology as applied to a steel shaft with a thin single-layer coating of bronze CuSn6. Recommended technological parameters for avoidance of welding imperfections are given. Filled CuSn6 bronze layers were assessed for hardness and consumption volume in terms of friction.     

The effect of retained austenite on the fracture toughness of high-speed steels

The aim of this work was to find the quantitative dependences between fracture toughness K_lc and the volume fraction of retained austenite in the matrix of quenched high-speed steels. The tests were carried out on three model alloys of a different content quotient of Mo: W which, after quenching, were gradually supercooled up to ? 196°C and then tempered at 450°C. Also the measurements of the content of retained austenite in the vicinity of the surface of a sample fracture were carried out. It was determined that after tempering at 450°C the fracture toughness of the matrix of high-speed steels is directly proportional to the content of retained austenite in it. Every 1 % by volume of retained austenite increases the fracture toughness K_lc of the matrix by about 5%, despite the fact that most probably it is completely transformed into fresh martensite in front of a propagating crack. Higher fracture toughness of the matrix of high-speed steels rich in molybdenum should be explained exlusively by a larger content of retained austenite. Transformations in the martensitic part of the matrix of the alloys richer in molybdenum clearly reduce the advantageous effect of retained austenite on this steel feature.     

Recovery of epichlorohydrin and dichloropropanols from waste

A method of recovery of the organic compounds: dichloropropanols, epichlorohydrin, 1,2,3-trichloropropane from epichlorohydrin plant waste has been performed. The method depends on the adsorption of organic compounds in the active carbon and their desorption by allyl chloride. Allyl chloride is desorbed by steam. After desorption the solutions are recirculated to the epichlorohydrin plant.     

Identification of Rheological Parameters on the Basis of Various Types of Compression and Tension Tests

The objective of the project was to determine flow stress on the basis of various plastometric tests. The experiments used uniaxial compression, ring compression, and plane strain compression for two sizes of samples and tensile tests. The material was carbon‐manganese steel, and all the tests were performed at three temperatures (900, 1000, and 1100°C) and at three strain rates for each temperature (0.1, 1, and 10 s^?1). Inverse analysis was applied to the interpretation of the results of all compression tests. The flow stresses obtained from various compression tests were compared resulting in the following observations: consistent results between the tests were observed for low values of the Zener‐Hollomon parameter, but some discrepancies appeared for larger values of this parameter. The sensitivity of the results of inverse analysis with respect to the friction factor was investigated next, and it was concluded that the flow stress determined from ring compression showed the largest sensitivity to friction. This sensitivity was lower for uniaxial compression and plane strain compression of small samples, and no sensitivity was observed for plane strain compression of large samples. Finally, the simulations of the tensile tests were performed using the rheological models determined in compression, and reasonably good results were obtained.     

Einfluß des Molybdäns auf die Zähigkeit von Schnellarbeitsstählen

Unterschiede im Gefüge von Schnellarbeitsstählen der Grundzusammensetzungen (%) 18W-0Mo-1V und 6W-5Mo-2V. Härten von Proben aus je einer Schmelze dieser Stähle und anschließendes Anlassen bei Temperaturen von 250 bis 650°C. Bruchmechanische Biegeprüfungen, quantitative Messung des Carbidteilchendurchmessers, rasterelektronenmikroskopische Untersuchungen und Messung der Oberflächenrauheit. Folgerungen, besonders über kritische Carbidteilchengrößen in Hinsicht auf das Rißwachstum.     

Making decisions in a two-stage identification system with knowledge updating

In this article, an algorithm for updating knowledge in an adaptive system to support decision making is proposed. Taking into account the specific character of the process, a two-stage identification approach is used. The first stage is built for diagnostic purposes, i.e., the estimated parameters in the first-stage relationship are used to make a decision at the second stage. The proposed algorithms to support decision making at the second stage rest on knowledge extracted from human experts and the effects of the diagnosis (based on identification results) at the first stage. To examine the effectiveness of the proposed algorithm, a numerical simulation of a biomedical problem is carried out.     

Effect of green manure on the incidence of cyanogenic Pseudomonas strains in hop garden soils

Incidence of cyanogenic Pseudomonas strains in hop garden soils in relation to the kind of fertilization was studied. Incidence differed with respect to the fertilization treatment and the age of the plantation. Amendment of soil with rye and with white mustard as green manures limited the number of cyanogenic Pseudomonas strains relative to farmyard manures and NPK fertilization. Among all fertilization treatments, cyanogenic Pseudomonas spp. strains had lowest populations in soils amended with white mustard.     

Novel 6-bromo-3-ethyl-2-styrylbenzothiazolium <Emphasis Type="Italic">n</Emphasis>-butyl-triphenylborates as photoinitiators of trimethylolopropane triacrylate (TMPTA) polymerization

Summary The series of 6-bromo-3-ethyl-2-styrylbenzothiazolium n-butyltriphenylborates was synthesized and evaluated as photoinitiators of free radical polymerization. The dyes were obtained by the condensation reaction of the 6-bromo-3-ethyl-2-methylbenzothiazolium salts with different alkylaminobenzaldehydes. The resulting styrylbenzothiazole dyes (hemicyanine dyes) paired with n-butyltriphenylborate anion (SBrB2), are shown to be efficient photoinitiators for free radical polymerization of trimethylolpropane triacrylate (TMPTA) induced with the visible emission of an argon-ion laser. The photochemistry of the novel hemicyanine borates was compared to the photochemistry of identical series of the dyes that do not possess the bromo substituent at benzothiazolium residue. The comparison has shown that the introduction of the bromine into benzothiazolium residue causes a small red shift of the electronic absorption maxima, changes the reduction potential of the dye and, finally, increases a photoinitiation ability of the dye.     

Toxic trace metals in food

Summary A new high-performance analytical procedure for the determination of the toxic trace metals cadmium, lead and copper in wines by differential pulse anodic-stripping voltammetry (DPASV) subsequent to UV irradiation of the sample is compared with the hitherto more common application of electrothermal atomic absorption spectrometry (AAS). In this manner also mutually the accuracy attainable with both alternatives has been established. The particularly favourable potentialities of the new voltammery approach for toxic metal control of wines are demonstrated by the investigation of a typical selection of 36 wines from recent vintages and common vine types of the German and some European wine cultivating regions.

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Toxische Spurenmetalle in LebensmittelnII. Eine vergleichende Studie über die Konzentration toxischer Spurenmetalle im Wein durch differentielle anodische Pulsinversvoltammetrie und elektrothermale Atomabsorptionsspektrometrie

Zusammenfassung Eine neue besonders leistungsfähige Methode zur Bestimmung der Gehalte der toxischen Spurenmetalle Cadmium, Blei und Kupfer in Weinen mit der differentiellen anodischen Pulsinversvoltammetrie (DPASV) nach vorhergehender UV-Bestrahlung der Probe wird mit der bislang weithin angewandten Alternative elektrothermale Atomabsorptionsspektrometrie (AAS) verglichen. Auf diese Weise wird auch wechselseitig die mit beiden methodischen Alternativen erhältliche Richtigkeit der Daten ermittelt. Die besonderen Vorzüge der neuen voltammetrischen Methode zur Kontrolle des Gehaltes toxischer Spurenmetalle im Wein demonstrieren die Resultate der Untersuchung einer typischen Auswahl von 36 Weinen der letzten Jahrgänge und wichtigsten Rebsorten aus den deutschen und einigen europäischen Hauptanbaugebieten.

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Attached from Institute of Fundamental Problems of Chemistry, University of Warsaw, Poland, in the frame of the joint research project on Toxic Metals in the Environment