bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Temperature of Accumulative Roll Bonding on the Microstructure and Mechanical Properties of AA5251 Aluminum Alloy
Authors: Bogucka J. 
Published: April 2014

Abstract
The influence of bonding temperature on microstructure and mechanical properties of AA5251 alloy sheets have been analyzed in the paper. The alloy was deformed with the method of accumulative roll bonding (ARB) in various temperature conditions i.e. at ambient temperature up to 5th cycle (ε = 4.0) and using pre-heating of sheet packs at 200°C and 300°C up to 10 cycles (ε = 8.0). The deformed material was subjected to structural observations using TEM, measurements of crystallographic texture with the technique of X-ray diffraction and tensile tests.
It was established that the temperature of roll-bonding had a significant effect on the structure evolution and the observed changes of mechanical properties. High refinement of microstructure and optimum mechanical properties were obtained for the material processed at lower temperatures, i.e. at ambient temperature and pre-heating at 200°C. Recovery structure processes occurring during deformation were observed in the alloy bonded with pre-heating at 300°C and therefore mechanical properties were lower than for the alloy bonded at lower temperatures.
The Portevin –Le Chatelier Effect and Acoustic Emission of Plastic Deformation CuZn30 Monocrystals
Authors: Ozgowicz W. , Grzegorczyk B. , Pawełek A. , Piatkowski A. , Ranachowski Z. 
Published: April 2014

Abstract
The paper presents the investigation of the relation between the acoustic emission (AE) and instability of plastic deformation type Portevin-Le Chatelier (PLC) of single-phase brass CuZn30 monocrystals with crystallographical orientation [1¯3 9]. The monocrystals have been investigated applying the method of free compression at a constant strain rate and the temperature within the range from 200°C to 400°C, simultaneously recording PLC phenomenon by means of acoustic emission. During hot axial compression tests the correlation between work-hardening curves σ - ε, which display PLC effect and characteristic of acoustic emission signals has been found. Moreover, it was proved that in the range of the PLC effect, the acoustic signal is an impulse a character of cyclic repeatability, distinctly correlated qualitatively with the stress oscillations on the curves σ - ε. The analysis of the obtained results leads to the conclusion that in the tested monocrystals the effect PLC is probably controlled by complex processes similar to the phenomenon of dynamic strain ageing (DSA), which are described by diffusion models.
Ball-milled Fe-Ni and Fe-Mn Matrix Powders For Sintered Diamond Tools
Authors: Romanski A. , Konstanty J. 
Published: April 2014

Abstract
The work presents the possibility of substitution of expensive, Co-WC powders, that have been traditionally used in the production of sintered diamond tools, with cheap iron-base counterparts manufactured by ball milling. It has been shown that ball-milled Fe-Ni and Fe-Mn powders can be consolidated to a virtually pore-free condition by hot pressing at 900°C. The as-consolidated materials are characterised by high hardness, bending strength and resistance to 3-body abrasion.
D-gun Sprayed Fe-Al Single Particle Solidification
Authors: Wołczyński W. , Senderowski C. , Morgiel J. , Garzeł G. 
Published: April 2014

Abstract
Some Fe-Al particles less than 50 μm in diameter were deposited onto the steel substrate by means of the D-gun spraying. A solidification mechanism of an individual particle is described. The particle subjected to the description contained nominally 63 at.% Al. The description was preceded by the TEM / SAED analysis of both the Fe-Al coating and Ni-20Cr interlayer. The whole number of the analyzed particles was partially melted during the deposition. The solidification products like: amorphous phase sub-layer, oscillatory sub-layer which contains two types lamellae distributed alternately and typically non-equilibrium phase sub-layer were revealed. In the micro scale, solidification was considered as a process which occurred in two directions: towards the substrate and towards the non-melted particle part. Both solidification processes underwent the positive thermal gradients. The boron addition was localized within the eutectic precipitates pushed and then rejected by the solid/liquid interface of the solidifying non-equilibrium phase. The proposed model is a general one and therefore can be applied to other systems ;description.
Influence of Bismuth Content on Complex Immittance Characteristics of Pressureless Sintered BiNbO4 Ceramics
Authors: Czekaj D. , Lisinńska-Czekaj A. , Adamczyk M. 
Published: April 2014

Abstract
Goal of the present research was to study immittance properties of BiNbO4 ceramics fabricated by the solid state reaction route followed by pressureless sintering. Four sets of samples were examined, namely the one fabricated from the stoichiometric mixture of oxides, viz. Bi2O3 and Nb2O5 as well as the ones with an excess of 3%, 5% and 10% by mole of Bi2O3. The immittance properties were studied by impedance spectroscopy. Measurements were carried out within the frequency range ν =20Hz-1MHz and temperature range T =RT-550°C. The Kramers-Kronig data validation test was employed in the impedance data analysis. It was found that complex impedance first increases with an increase in Bi2O3 content and decreases for 10mol% excess of Bi2O3. Two relaxation phenomena manifested themselves at elevated temperature (T>267°C) within the measuring frequency range. The conductivity relaxation phenomenon (M″(ν) spectra) took place at higher frequency than the phenomenon with dominant resistive component (Z″(ν) spectra).
Iron and Bronze Powdered Based Materials for Bearings with Surface Modified with Solid Lubricant Nanoparticles
Authors: Lijewski M. , Leshynsky V. , Wisniewska-Weinert H. , Sulej-Chojnacka J. , Rybak T. 
Published: April 2014

Abstract
In the recent years, a growth of demand for various types of self-lubricating elements of machines has been observed. A lot of parts are manufactured with the use of a powder metallurgy method. The Metal Forming Institute (INOP) in Poznan developed a modern technology, designed and made a tool for compaction of powdered parts with complex shapes and high density. The technology is being realised with a large scale equipment, which performs the forging and sizing of the sintered performs.
The present work describes development of manufacturing technology and determination of mechanical and tribological properties of nanocomposites for self-lubricating bearings with a very low friction coefficient. It is envisaged to use particulate materials which consist of nano-and microparticles of solid lubricant.
The study conducted aims at definition of a relationship between the microstructure and tribological properties of materials modified with solid lubricant MoS2 nanoparticles dispersed in a technological oil. INOP’s technology of nanoparticles manufacturing by RCT method (Rolling Cleavage Technology) results in that top layer of the porous bearing is modified with the nanoparticles. These layers are characterised by a low friction coefficient and considerably longer period of use. It should be noted that the stainless steel and bronze powders materials used have a good corrosion resistance. Production of the sintered bearings will disseminate the market especially in automotive and aircraft industries.
Surface Tension of Cu – Bi Alloys And Wettability in a Liquid Alloy – Refractory Material – Gaseous Phase System
Authors: Oleksiak B. , Łabaj J. , Wieczorek J. , Blacha-Grzechnik A. , Burdzik R. 
Published: April 2014

Abstract
The study involved measurements of surface tension of liquid binary copper-bismuth alloys with respect to their chemical composition and temperature as well as investigations of the liquid alloy - refractory material - gaseous phase system wettability using usual refractory materials, i.e. aluminium oxide, magnesium oxide and graphite. The experiments were performed with the use of sessile drop method and a high-temperature microscope coupled with a camera and a computer was utilised.
Microstructure and Creep Resistance of Mg-Al-Ca-Sr Alloys
Authors: Rzychoń T. , Adamczyk-Cieślak B. 
Published: April 2014

Abstract
Microstructure and creep properties of cast Mg-Al-Ca-Sr alloys have been investigated. The microstructure was characterized using light microscopy, scanning and transmission electron microscopy. Phase identification was made by EBSD technique and by SAED analysis. The measurement of volume fraction of intermetallic phases was performed using quantitative metallography. Creep tests were performed at 180°C and at applied stress between 45 and 90 MPa. Microstructure of tested alloys composed of α-Mg grains and intermetallic compounds in the interdendritic regions. It was found that the addition of calcium and strontium improves creep resistance at 180°C.
Aluminium AlMg1SiCu Matrix Composite Materials Reinforced with Halloysite Particles
Authors: Dobrzański L.A. , Tomiczek B. , Pawlyta M. , Król M. 
Published: April 2014

Abstract
In this work selected results of investigations of the new AlMg1SiCu matrix composite materials reinforced with halloysite particles manufactured by powder metallurgy techniques including mechanical alloying and hot extrusion are present. The composite materials obtained as a result of mechanical synthesis and hot extrusion are characterized with the structure of evenly distributed, disperse reinforcing phase particles in fine-grain matrix of AlMg1SiCu alloy, facilitate the obtainment of higher values of strength properties, compared to the initial alloy. The nanostructural composite materials reinforced with halloysite nanotubes with 15 mass % share are characterized by almost twice as higher micro-hardness - compared to the matrix material.
Influence of the Zinc Sublayer Method Production and Heat Treatment on the Microhardness of the Composite Ni-Al2O3 Coating Deposited on the 5754 Aluminium Alloy
Authors: Karaś M. , Nowak M. , Opyrchał M. , Bigaj M. , Najder A. 
Published: April 2014

Abstract
In this study, the effect of zinc interlayer on the adhesion of nickel coatings reinforced with micrometric Al2O3 particles was examined. Nickel coating was applied by electroplating on EN AW - 5754 aluminium alloy using Watts bath at a concentration of 150 g/l of nickel sulphate with the addition of 50 g/l of Al2O3. The influence of zinc intermediate coating deposited in single, double and triple layers on the adhesion of nickel coating to aluminium substrate was also studied. The adhesion was measured by the thermal shock technique in accordance with PN-EN ISO 2819. The microhardness of nickel coating before and after heat treatment was additionally tested.
It was observed that the number of zinc interlayers applied does not significantly affect the adhesion of nickel which is determined by thermal shock. No defect that occurs after the test, such as delamination, blistering or peeling of the coating was registered. Microhardness of the nickel coatings depends on the heat treatment and the amount of zinc in the interlayer. For both single and double zinc interlayer, the microhardness of the nickel coating containing Al2O3 particles increased after heat treatment, but decreased when a triple zinc interlayer was applied.
Evaluation of the Effect of Selected Alloying Elements on the Mechanical and Electrical Aluminium Properties
Authors: Mamala A. , Sciężor W. 
Published: April 2014

Abstract
Modern industry expects aluminum products with new, unusual, and well-defined functional properties. Last years we are able to notice constant development of aluminium alloys. In food industry, power engineering, electrical engineering and building engineering, flat rolled products of 1XXX series aluminium alloys are used.8XXX series alloys registered in Aluminium Association during last 20 years may be used as an alternative. These alloys have very good thermal and electrical conductivity and perfect technological formability. Moreover, these materials are able to obtain by aluminium scrap recycling. Fundamental alloy additives of 8XXX series are Fe, Si, Mn, Mg, Cu and Zn. Aluminium alloying with these additives makes it possible to obtain materials with different mechanical ale electrical properties. In this paper, the analysis of alloy elements content (in 8XXX series) effect on chosen properties of material in as cast and after thermal treatment tempers has been presented.
Phytoplankton composition and physicochemical properties in Lake Swarzędzkie (midwestern Poland) during restoration: Preliminary results
Authors: Kozak Anna , Kowalczewska-Madura Katarzyna , Gołdyn Ryszard , Czart Anna 
Published: April 2014

Abstract
This paper presents the preliminary results of a study of the phytoplankton structure and dynamics and physicochemical properties of Lake Swarzędzkie in 2011. The subject of the study is a shallow, elongated, post-glacial lake located in western Poland. The surface area is 93.7 ha with a maximum depth of 7.2 m. Its poor water quality led to the implementation of chemical and biological restoration procedures in an attempt to improve it. The highest concentration of total nitrogen was 13.07 mg l-1 N. Secchi depth (SD) was low in the summer with a minimum value of 0.5 m in September. The most abundant group of phytoplankton were cyanobacteria, and the maximum value of chlorophyll a concentration was 278.0 μg l-1. The dominant species were Pseudanabaena limnetica and Aphanizomenon gracile. Cyanobacteria were the most abundant phytoplankton until November. Maximum diatom, cryptophyte, and chrysophyte density was noted in the spring, and the most abundant were Nitzschia acicularis, Cryptomonas marssonii, Rhodomonas lacustris, Erkenia subaequiciliata, and Dinobryon sociale. One-hundred and thirty-six phytoplankton taxa belonging to nine taxonomic groups were identified in Lake Swarzędzkie. The highest number of taxa was noted among chlorophytes (57 taxa), cyanobacteria (19), diatoms (16), and chrysophytes (12), while other taxonomic groups were represented by smaller number of taxa.
Slope stability analysis with geo 5 software for “Łaski” Landslide in Międzybrodzie Bialskie
Authors: Michalski Andrzej 
Published: April 2014

Abstract
Abstract. Numerical modeling is an important tool to estimate slope stability. This publication shows application of a GEO 5 - slope stability software to evaluate stability of the “Łaski” Landslide in Międzybrodzie Bialskie. The slide surfaces, which were indentified in drill cores, were used to compute factors of safety (FS). The data from inclinometric measurements were used to verify the numerical model of the landslide. Calculations were carried out for three scenarios: first with normal water level, second scenario with lowered water level of 5 m and 10 m and the third scenario without water with the worst courses of sliding surfaces. As the result for each scenario the factors of safety were estimated. It was found that despite of water lowering and stabilization of existed surfaces, there is a considerable risk of a new sliding surfaces occurrence.
An application of geoelectrical methods for contamination plume recognition in Urbanowice waste disposal
Authors: Mycka Mateusz , Mendecki Maciej Jan 
Published: April 2014

ABSTRACT
The purpose of this work was to detect groundwater pollution and to identify the conditions of soil and groundwater near the Urbanowice landfill site using geoelectrical measurements. Presented measurements are preliminary results from tested site and are beginning of continuous monitoring. Contamination outflows detected by resistivity and IP technique show a good correlation with available hydrological data. Contamination plume were found in Eastern part of survey profil.
Metallophytes in biotopes polluted by waste dumps rich in Zn-Pb, Cd (Olkusz region) – review of previous and planned research
Authors: Rożek Dorota 
Published: April 2014

Abstract
The aim of that publication was the presentation of previous and planned research concerning selected vascular plants and soils near Olkusz (Southern Poland). The extremely high concentration of heavy metals in soils from that region was caused by the natural geochemical aureoles of dispersed metals (due to weathering of Zn-Pb-Fe ore sulphides) and mining and processing of shallowly occurring metalliferous deposits (containing Ag-Pb and Zn-Pb ores) since XII century. The condition of stress in metals, shortage of water and some plant nutrition led to formation of some adaptable vegetation features by plants growing in that region. Some species called metallophytes have been already detailed investigated. Moreover some geochemical and pedological research of soil have been already done. However the conditions of habitat of pioneering species such as Koeleria glauca and Corynephorus canescens are not still recognized.
Application of multivariate data analysis in the construction of predictive model for the chemical properties of coke
Authors: Sajdak Marcin , Smędowski Łukasz 
Published: April 2014

ABSTRACT
The aim of this work was to develop a statistical model which can predict values describing chemical composition of cokes performed in industrial scale. This model was developed on the basis of data that were taken from the production system used in the one of Polish coking plant. Elaborated equation include quality parameters of initial coals that form coal blends as well as contribution of additions such as coke and petrochemical coke. These equations allow to predict chemical composition of coke, e.g. contributions of: sulphur, ash, phosphorus and chlorine within the coke. A model was elaborated with use of STATISTICA 10 program and it is based on factor and multiply regression analyses. These analyses were chosen from among few kinds of regression analyses. They allowed to develop prediction model with the required goodness of fit between calculated and actual values. Goodness of fit was elaborated with:
• residuals analyses,
• residues normality and predicted normality
• mean absolute error
• Pearson correlation confidence
Gamma-ray-based measurement of concentration distribution in pipe flow of settling slurry: vertical profiles and tomographic maps
Authors: Krupička Jan , Matoušek Václav 
Published: April 2014

Abstract
Principles of gamma-ray-based measurement are summarized and their application is demonstrated on an operation of the radiometric facility installed in the test loop for slurry flows at the Institute of Hydrodynamics. The facility is able to measure vertical profiles of chord-averaged concentrations and concentration maps in the pipe cross section. A methodology of measurement is proposed including detection and quantification of random and systematic errors. Experimental results are discussed in the light of the proposed methodology. Experimentally determined vertical profiles of concentration are presented for slurry flows of four different fractions of glass beads. The tomographic application of the radiometric device is demonstrated on a measured concentration map and a suitable image reconstruction method is tested. High reliability of measured concentration distributions is proved except for regions near the pipe wall. The radiometric method is shown to be a useful tool for measurement of concentration distribution in slurry flow through a pipe.
Three-dimensional flow of an Oldroyd-B fluid over a bidirectional stretching surface with prescribed surface temperature and prescribed surface heat flux
Authors: Hayat Tasawar , Shehzad Sabir Ali , Alsaedi Ahmed 
Published: April 2014

Abstract
This paper concentrates on the mathematical modelling for three-dimensional flow of an incompressible Oldroyd- B fluid over a bidirectional stretching surface. Mathematical formulation incorporates the effect of internal heat source/sink. Two cases of heat transfer namely the prescribed surface temperature (PST) and prescribed surface heat flux (PHF) are considered. Computations for the governing nonlinear flow are presented using homotopy analysis method. Comparison of the present analysis is shown with the previous limiting result. The obtained results are discussed by plots of interesting parameters for both PST and PHF cases. We examine that an increase in Prandtl number leads to a reduction in PST and PHF. It is noted that both PST and PHF are increased with an increase in source parameter. Further we have seen that the temperature is an increasing function of ratio parameter
Sergiusz Hessen (1887 – 1950) – as creative European educationalist with no homeland
Authors: Kucha Ryszard , Świderska Mariola 
Published: April 2014

Abstract
This article examines the life and scientific career of the prominent European educationalist and pedagogue Sergiusz Hessen. His pedagogical heritage is examined on the base of basic primary writing and archive sources prepared in different languages. We are trying to show the contribution of the Hessen`s activity in the research methodology of multicultural societies and education, his philosophy of education, teaching knowledge, as well as in the real process of university and school education.
Adaptive inventory control system for material items with continuous non-stationary demand
Authors: Krajčovič Martin , Plinta Dariusz 
Published: April 2014

Abstract
This paper describes an algorithm of dynamic inventory control system for large numbers of material items with continuous non-stationary demand. It uses principles of pull inventory control systems, statistical inventory analysis and joint replenishment inventory systems. This algorithm was processed in software module (VBA for Excel) and applied in practice. The target of described algorithm is to keep an optimum inventory level and optimum customer service level in terms of inventory control of items with non-stationary demand.
Management trust, organizational trust, and organizational performance: advancing and measuring a theoretical model
Authors: Paliszkiewicz Joanna , Koohang Alex , Gołuchowski Jerzy , Horn Nord Jeretta 
Published: April 2014

Abstract
The purpose of this study was to propose a theoretical model and empirically measure whether trust impacts organizational performance. This study focused on three constructs: management trust (MT); organizational trust (OT); and organizational performance (OP). Specifically, the results of this study determined whether management trust (MT) significantly and positively contributes to organizational trust (OT) and whether organizational trust (OT) significantly and positively contributes to organizational performance (OP). Based on the findings, recommendations were made for building and sustaining a culture that will lead to improved organizational performance).
Investigations of harbour brick structures by using operational modal analysis
Authors: Żółtowski Mariusz 
Published: April 2014

ABSTRACT
Historic harbour brick objects are subject to large dynamic loads clearly reflected by generated vibration processes. The vibrations may affect state of serviceability of structures by lowering comfort of persons working there as well as possible reaching the level hazardous to safety of the structures. The effect of vibrations to structure is mainly manifested by additional stresses in a given cross-section, which are summed up with those resulting from static loads. Moreover often occur consequences associated with environmental conditions and fatigue of materials which accelerate destruction of the objects. Therefore the dynamic loads may cause damaging effects in buildings of various structural types or even lead to their catastrofic destruction. Judging the necessity of improving the quality assessment methods of building structures for purposes of estimation of their state as well as safety factors for brick structures (see PN-B- 03002 standard, p.3.1.3 and 4.6), the author of this work undertook an attempt to investigate destruction process of selected building structures by using the method of operational modal analysis.