bluuebunny/crossref_metadata_2025_split huggingface dataset:
Schauder’s fixed-point theorem in approximate controllability problems
Authors: Babiarz Artur , Klamka Jerzy , Niezabitowski Michał 
Published: July 2016

Abstract
The main objective of this article is to present the state of the art concerning approximate controllability of dynamic systems in infinite-dimensional spaces. The presented investigation focuses on obtaining sufficient conditions for approximate controllability of various types of dynamic systems using Schauder’s fixed-point theorem. We describe the results of approximate controllability for nonlinear impulsive neutral fuzzy stochastic differential equations with nonlocal conditions, impulsive neutral functional evolution integro-differential systems, stochastic impulsive systems with control-dependent coefficients, nonlinear impulsive differential systems, and evolution systems with nonlocal conditions and semilinear evolution equation.
Exact and heuristic approaches to solve the Internet shopping optimization problem with delivery costs
Authors: Lopez-Loces Mario C. , Musial Jedrzej , Pecero Johnatan E. , Fraire-Huacuja Hector J. , Blazewicz Jacek , Bouvry Pascal 
Published: July 2016

Abstract
Internet shopping has been one of the most common online activities, carried out by millions of users every day. As the number of available offers grows, the difficulty in getting the best one among all the shops increases as well. In this paper we propose an integer linear programming (ILP) model and two heuristic solutions, the MinMin algorithm and the cellular processing algorithm, to tackle the Internet shopping optimization problem with delivery costs. The obtained results improve those achieved by the state-of-the-art heuristics, and for small real case scenarios ILP delivers exact solutions in a reasonable amount of time.
Numerical Analysis of a Rolling Process for Producing Steel Balls Using Helical Rolls
Authors: Chyła P. , Pater Z. , Tomczak J. , Chyła P. 
Published: July 2016

Abstract
This paper presents the research results of the balls rolling process according to the conventional and modified methods of rolling. Theoretical analysis was carried out by using numerical methods based on the Finite Element Method. The Simufact package version 10.0 were used for calculation. Simulations of balls rolling were carried out under conditions of 3D state of strain, taking into account the effect of thermal conditions occurring during forming. The study of the achieved results showed that the best rolling process parameters were obtained for the modified method, in which the feed material is heated up to 1150 °C. In this case, the rolling parameters such as: rolling force and torque as well as tool wear reached the smallest values.
Material Factors in Relation to Development Time in Liquid-Penetrant Inspection. Part 1. Material Factors
Authors: Irek P. , Słania J. 
Published: July 2016

Abstract
In technical publications and European Standards the development time (i.e. time of getting out of penetrant from a discontinuity to the material surface) in penetration testing is specified within the range of 10-30 minutes. In practice, however, it is seen , that it is closely connected
with the material type and ranges from several minutes to 24 hours. In the literature, only interactions coming from the penetrant are described, whereas those from the material under testing, i.e. the influence of material factors on adhesion between penetrant and material, are not taken into consideration. In this connection, it has been described precisely in the paper the adhesion phenomenon and also it has been indicated the other factors affecting the development time. Recapitulating the adhesion theories presented in the paper, it can be formulated two fundamental circumstances which must occur that adhesion joint may be formed, namely: the approach of the particles of two solids to the distance less than 0,9 nm while the high attractive force occurring between molecules should be connected with possibly low potential energy of the bond formed in this way.
Diversification of Intermetallic Zn Phases Growth on Steel During Hot-Dip Galvanizing
Authors: Węgrzynkiewicz S. , Jędrzejczyk D. , Szłapa I. , Hajduga M. , Boczkal S. 
Published: July 2016

Abstract
The steel substrate formed as the result of oxy-acetylene cutting (OAB) was treated differently - using: softening annealing, grinding and electro-polishing. Investigations were focused on the influence of additional processing on the structure and corrosion resistance of the deposited zinc coating. The hot - dip Zn galvanizing process was conducted in industrial conditions. Parameters were fixed: temperature 457 °C, dipping time 150 s. The coating thickness diversification dependent on the sub-surface steel structure was analysed and compared to the previous results. The correlation between conducted treatment and coatings morphology was determined.
Reduction of Deformations during Welding Metal Wire Mesh with Frames
Authors: Krawczyk R. , Slania J. 
Published: July 2016

Abstract
The article presents an issue referring to a reduction of deformation during welding metal wire mesh into the frames. A problem of a possible reduction of deformations was described taking into account characteristics of a construction of a welded element. Technological tests and their results are provided. Technological recommendations relating to the reduction of deformations of the welded element are given.
Stem-EDX and FIB-SEM Tomography of ALLVAC 718Plus Superalloy
Authors: Kruk A. , Cempura G. , Lech S. , Czyrska -Filemonowicz A. 
Published: July 2016

Abstract
Allvac 718Plus (718Plus) is a high strength, corrosion resistant nickel- based superalloy used for application in power generation, aeronautics and aerospace industry. The 718Plus microstructure consists of a γ matrix with γ’-Ni3(Al,Ti) and some δ- Ni3Nb phases as well as lamellar particles (η-Ni3Ti, η*-Ni6AlNb or Ni6(Al,Ti)Nb) precipitated at the grain boundaries.
The primary strengthening mechanism for this alloy is a precipitation hardening, therefore size and distribution of precipitates are critical for the performance of the alloy. The aim of this study was to characterize precipitates in the 718Plus superalloy using Scanning Transmission Electron Microscope combined with Energy Dispersive X-ray Spectroscopy (STEM-EDX) and Focused Ion Beam Scanning Electron Microscope (FIB-SEM). The STEM-EDX and FIB-SEM tomography techniques were used for 3D imaging and metrology of the precipitates. Transmission electron microscopy and EDX spectroscopy were used to reveal details of the 718Plus microstructure and allow determine chemical composition of the phases. The study showed that electron tomography techniques permit to obtain complementary information about microstructural features (precipitates size, shape and their 3D distribution) in the reconstructed volume with comparison to conventional particle analysis methods, e.g. quantitative TEM and SEM metallography
Effect of Sb-Modification on the Microstructure and Mechanical Properties of Secondary Alloy 319
Authors: Medlen D. , Bolibruchova D. 
Published: July 2016

Abstract
319 alloy has been selected for the study in the present work due to its wide use in many applications. 319 alloy is used in automotive and aerospace industry for the complicated castings which must comply high strength requirements. In practice, the most common elements with the modifying effect are strontium, sodium and antimony. The addition of these elements leads to a change in the shape of eutectic silicon, resulting in an increase of the mechanical characteristics and the microstructure. An experimental program has been undertaken to explore the effect of antimony on chosen mechanical properties and the microstructure of investigated alloy. An analysis of the results of these experimental works is made in order to determine an optimum Sb (Al-10% Sb) addition to produce material exhibiting desirable properties. Experimental works have showed that the addition of the Al-10% Sb results in similar or even higher mechanical properties than the conventional 319 alloy. Based on the carried out experiments the best combination of mechanical properties has been achieved by the addition of 2 000 ppm Al-10% Sb.
Formation of Transition Phases on Interface between Monocrystalline Fe and Cu Due to Mutual Solid-State Diffusion
Authors: Perek-Nowak M. , Boczkal G. 
Published: July 2016

Abstract
Interdiffusion between Fe (Armco) and Cu single crystals of similar orientation (around [110]) annealed at temperatures of 873 and 973K in air for 0.5 up to 4 h is studied. Formation of three phases different in their chemical composition has been observed: 1) oxide layer on Cu border (porous), 2) a layer rich in copper, iron and oxygen, 3) a layer of iron and oxygen with only small addition of Cu. All reactions of interface formation occurred in solid state. It was noted that oxygen plays an important role in development of new phases. Strong Kirkendall effect is observed due to large difference in diffusion coefficients of copper atoms to iron, DCu→Fe=300exp(-67800/RT) and iron atoms to copper DCu→Fe=0.091exp(-46140/RT).
Structural, Mechanical and Tribological Properties of Spark Plasma Sintered Ti6Al4V Alloy
Authors: Mróz A. , Garbiec D. , Wielowiejska-Giertuga A. , Wiśniewski T. , Gierzyńska-Dolna M. , Martyła A. 
Published: July 2016

Abstract
The influence of spark plasma sintering parameters on the structural, mechanical and tribological characteristics of the Ti6Al4V alloy, which is used as implant material in biomedical engineering, was investigated. The experimental data confirm that full density and attractive mechanical properties can be obtained using the spark plasma sintering method. Tribological tests, performed in dry conditions, allowed the authors to indicate the most suitable sintering parameters. The material characterized by the highest wear resistance was selected for further tribological testing in articulation with UHMWPE in simulated body fluids. Although the weight of the polymeric material articulating against the sintered Ti6Al4V was slightly higher compared to the UHMWPE articulating against the reference material (Ti6Al4V rod), the friction coefficient was lower.
Evaluation of Corrosion Resistance of Titanium Alloys Used for Medical Implants
Authors: Szewczenko J. , Marciniak J. , Kajzer W. , Kajzer A. 
Published: July 2016

Abstract
The study presents the results of investigations of modeling the usable properties of implant surfaces made of Ti6Al7Nb alloy, using the example of a dynamic hip screw (DHS) applied in surgical treatment of intertrochanteric femoral neck fractures. Numerical simulation has been performed for the model load of femoral fixation with DHS screw. The load simulation results provided the basis to select mechanical properties of the fixator elements and to define those fixation areas which are mostly susceptible to development of corrosion. The surfaces of Ti6Al7Nb alloy were ground, vibro-abrasive machined, mechanically polished, sandblasted, anode oxidized at different voltage values and steam sterilized. Results of surface topography evaluation, resistance to pitting and crevice corrosion as well as degradation kinetics of the outer layer were presented. Usability of the formed passive layer in clinical applications was evaluated through wear and corrosion tests of the femoral fixation model. The test results proved usefulness of the proposed surface modification methods for clinical application of different size and shape implants
Creep Behaviour of Modified Mar-247 Superalloy
Authors: Cieśla M. , Mańka M. , Binczyk F. , Gradoń P. 
Published: July 2016

Abstract
The paper presents the results of analysis of creep behaviour in short term creep tests of cast MAR-247 nickel-based superalloy samples made using various modification techniques and heat treatment. The accelerated creep tests were performed under temperature of 982 °C and the axial stresses of σ = 150 MPa (variant I) and 200 MPa (variant II). The creep behaviour was analysed based on: creep durability (creep rupture life), steady-state creep rate and morphological parameters of macro- and microstructure. It was observed that the grain size determines the creep durability in case of test conditions used in variant I, durability of coarse-grained samples was significantly higher.
Mechanical Properties of High-Mn Austenitic Steel Tested under Static and Dynamic Conditions
Authors: Dobrzański L. A. , Borek W. , Mazurkiewicz J. 
Published: July 2016

Abstract
The purpose of the paper is to investigate X73MnSiAlNbTi25-1-3 high manganese austenitic steel containing 0.73% C to determine structural mechanisms decisive for increasing a reserve of cold deformation energy of such steel. The influence of a strain rate on the structure of the investigated steels and on the structural mechanisms decisive for their properties was analysed. Specialist research instrumentation was used for this purpose such as Scanning Transmission Microscopy (including EBSD examinations), conventional and high-resolution transmission electron microscopy together with diffraction examinations and metallographic examinations. It was found that the principal cause of an increased reserve of cold deformation energy of the investigated steels in dynamic conditions is the activation of mechanical twinning in the mutually intersecting systems in austenite grains and annealing twins, which are densifying when a cold deformation rate is growing, thereby confirming the basic mechanism of TWIP (TWinning Induced Plasticity).
The Use of Fuzzy Systems for Forecasting the Hardenability of Steel
Authors: Sitek W. , Irla A. 
Published: July 2016

Abstract
The goal of the research carried out was to develop the fuzzy systems, allowing the determination of the Jominy hardenability curve based on the chemical composition of structural steels for quenching and tempering. Fuzzy system was created to calculate hardness of the steel, based on the alloying elements concentrations, and to forecast the hardenability curves. This was done based on information from the PN-EN 10083-3: 2008. Examples of hardenability curves calculated for exemplar steels were presented. Results of the research confirmed that fuzzy systems are a useful tool in evaluation the effect of alloying elements on the properties of materials compared to conventional methods. It has been demonstrated the practical usefulness of the developed models which allows forecasting the steels’ Jominy hardenability curve.
Nanocrystalline TiO2 Powder Prepared by Sol-Gel Method for Dye-Sensitized Solar Cells
Authors: Dobrzański L. A. , Szindler M. M. , Szindler M. , Lukaszkowicz K. , Drygała A. , Prokopiuk vel Prokopowicz M. 
Published: July 2016

Abstract
In this study titanium dioxide nanopowder has been manufactured and examined. Nanocrystalline TiO2 powder has been obtained by hydrolysis and peptization of a solution of titanium isopropoxide and isopropanol. Subsequently, produced powder has been subjected to structural analysis by using a transmission electron microscope, X-ray diffractometer, and Raman spectrometer. For comparison purposes, a commercially available titanium dioxide powder (i.e. titanium white) was also used. Thin layers have been made from this powder and further have been examined by using a UV/VIS spectrometer. Completed research shows the nanocrystalline structure of obtained layers and their good properties such as absorbance at the range of wavelength equal 200 - 1000 nm.
Characteristic of Oxide Layers Obtained on Titanium in the Process of Thermal Oxidation
Authors: Aniołek K. , Kupka M. , Barylski A. , Mieszczak Ł. 
Published: July 2016

Abstract
Thermal oxidation in air may be one method to improve the properties of titanium and its alloys through its influence on the structure and properties of the material’s surface layer. This paper presents a description of oxide layers obtained on the surface of Grade 2 titanium as a result of oxidation at temperatures of 600 and 700°C. On the basis of kinetic curves, it was found that the intensity of oxide layer growth increased with oxidation temperature. Studies of the surface morphology of oxide layers showed that the size of the formed oxide particles was greater following oxidation at 600°C. The obtained layers were subjected to X-ray phase analysis and microhardness measurements. Irrespective of oxidation temperature, the scale consisted of TiO2 oxide in the crystallographic form of rutile and of Ti3O oxide. The hardness of oxide layers amounted to around 1265 HV and was more than 4 times higher compared to the material in i ts initial state.
Structure and Magnetic Properties of Bi5Ti3FeO15 Ceramics Prepared by Sintering, Mechanical Activation and Edamm Process. A Comparative Study
Authors: Jartych E. , Pikula T. , Mazurek M. , Franus W. , Lisinska-Czekaj A. , Czekaj D. , Oleszak D. , Surowiec Z. , Aksenczuk A. , Calka A. 
Published: July 2016

Abstract
Three different methods were used to obtain Bi5Ti3FeO15 ceramics, i.e. solid-state sintering, mechanical activation (MA) with subsequent thermal treatment, and electrical discharge assisted mechanical milling (EDAMM). The structure and magnetic properties of produced Bi5Ti3FeO15 samples were characterized using X-ray diffraction and Mössbauer spectroscopy. The purest Bi5Ti3FeO15 ceramics was obtained by standard solid-state sintering method. Mechanical milling methods are attractive because the Bi5Ti3FeO15 compound may be formed at lower temperature or without subsequent thermal treatment. In the case of EDAMM process also the time of processing is significantly shorter in comparison with solid-state sintering method. As revealed by Mössbauer spectroscopy, at room temperature the Bi5Ti3FeO15 ceramics produced by various methods is in paramagnetic state.
Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
Authors: Bąk W. , Kajtoch C. , Ptaszek S. , Lisińska-Czekaj A. , Czekaj D. , Ziętek D. , Glos T. , Garbarz-Glos B. 
Published: July 2016

Abstract
The results of the microstructural and dielectric measurements of (Ba1-xPbx)(Ti1-xSnx)O3 (BPTSx) (x = 0, 0.05, 0.10, 0.30) polycrystalline samples are presented. The samples were obtained by means of a high temperature synthesis and their expected stoichiometry was confirmed by energy dispersive spectroscopy (EDS) measurements. The dielectric properties of BPTSx were studied with the use of broadband dielectric spectroscopy. The measurements over a wide range of temperature (from 140 K to 600 K) and frequency (from 0.1 Hz to 10 MHz) were performed. The experimental results indicate an influence of Pb ions in a sublattice A and Sn ions in a sublattice B substitution on paraelectric - ferroelectric phase transition parameters. Diffused phase transitions from a paraelectric to ferroelectric state (for x = 0.10 and x = 0.30) were observed. From the electric modulus measurements in the frequency domain the relaxation times and the activation energy were determined.
Antibacterial Composite Layers on Ti: Role of ZnO Nanoparticles
Authors: Roguska A. , Belcarz A. , Suchecki P. , Andrzejczuk M. , Lewandowska M. 
Published: July 2016

Abstract
Problem of post-operative infections of implant materials caused by bacterial adhesion to their surfaces is very serious. Enhancement of antibacterial properties is potentially beneficial for biomaterials value. Therefore, the metallic and metallic oxide nanoparticles attract particular attention as antimicrobial factors. The aim of this work was to create nanotubular (NT) oxide layers on Ti with the addition of ZnO nanoparticles, designed for antibacterial biomedical coatings. Antimicrobial activities of titanium, TiO2 NT and ZnO/TiO2 NT surfaces were evaluated against bacterial strain typical for orthopaedic infections: S. epidermidis. TiO2 NT alone killed the free bacterial cells significantly but promoted their adhesion to the surfaces. The presence of moderate amount of ZnO nanoparticles significantly reduced the S. epidermidis cells adhesion and viability of bacterial cells in contact with modified surfaces. However, higher amount of loaded nanoZnO showed the reduced antimicrobial properties than the medium amount, suggesting the overdose effect.
Shaping of Panel Materials in Light Direction Design
Authors: Urzędowski A. , Wójcicka-Migasiuk D. 
Published: July 2016

Abstract
The paper presents the methodology of the analysis of the materials used in solar energy conversion, and an elaborated example with simulations of obtained results. Material properties are selected in relation to the need of sunlight illumination applications in civil constructions. This process is presented , starting from the analysis of some aspects of solar radiation, through the calculations of lens curvature and leading to the execution of simulations in different conditions. Graphical presentation of the phenomenon, it can visualize the process of shaping curves. The materials such as glass, polymers, metals, and gases have been discussed. Particular attention was paid to the results of the transmission of materials, their reflection and absorption of solar radiation. Moreover, the research problems of illumination and reflection in multi-layer structures used for civil constructions have been presented.
Changes In Properties and Microstructure of High-Chromium 9-12%Cr Steels Due to Long-Term Exposure at Elevated Temperature
Authors: Zieliński A. , Dobrzański J. , Purzyńska H. , Golański G. 
Published: July 2016

AbstractThis paper presents the characteristics of the performance of P91 (X10CrMoVNb9-1), P92 (X10CrWMoVNb9-2) and VM12 (X12CrCoWVNb12-2-2) steels used for condition assessment of the pressure components of boilers with supercritical steam parameters. Studies on the mechanical properties, microstructure tests using scanning and transmission electron microscopy, and X-ray analysis of the phase composition of precipitates were performed for selected steels in the as-received condition and after long-term annealing. These steel characteristics are used for the evaluation of the microstructural changes and mechanical properties of the material of components after long-term service. The result of this study is the database of material characteristics representing the mechanical properties related to the microstructure analysis and it can be used for diagnosis of the components of pressure parts of power boilers.
Specific Bending and Compressive Strenght of Poly(Vinyl Alcohol)-CNT Composites
Authors: Zygoń P. , Nitkiewicz Z. 
Published: July 2016

Abstract
Carbon nanotubes are one of the strongest materials of unique mechanical, optical, electrical and electronic properties. Because of that they are mainly used as semiconductor materials constituting the reinforcing phase in composite materials.
The paper presents properties of polymer composites reinforced with carbon nanotubes (CNT) containing various mixtures of dispersion. Produced composites featured various content carbon nanotubes: 20%, 30%, 40% i 50%. Macroscopic observations were carried out on ready to check composites, if pores exist in the structure and whether the reinforcement has been distributed in the entire volume. Bending and compressive strengths tests were performed and densities of individual composites were measured to determine the specific strength.
Composite materials strengthened with carbon nanotubes feature a very low density and a very good mechanical strength, which makes them a good structural material.
Gas Evolution Quantitative Analysis at a Temperature of 900°C of a Cellulose Mixture Modified by Mineral Additives
Authors: Zawieja Z. , Sawicki J. 
Published: July 2016

Abstract
This article presents a gas evolution study of a novel, cellulose-based mixture with such mineral additives as expanded perlite, expanded vermiculite and microspheres. Inorganic alumina-silica binder was used to produce an uniform, bound mixture. The results have shown that the novel, cellulose-based mixture, obtained from waste paper, with mineral additives, emits smaller amounts of gas, while retaining the same thermal resistance.