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Marcin Mazur

Abstract

The author of the article discusses the subject of terminology in the field of cartographic methodology. The general purpose is to propose an internally consistent system of concepts which allows classification of cartographic presentation methods based on unambiguous criteria. For this purpose, in the article the concept of presentation method and the concept of presentation form were differentiated, the cartographic presentation method was divided into stages, and possible data transformation and visualization aspects during application of a method were specified. Then, review of the previous classifications of cartographic presentation methods was conducted which allows differentiation of two fundamental approaches to classification and comparison of the applied criteria. On this basis, the author’s classification of cartographic presentation methods was suggested in which three qualitative and four quantitative methods were differentiated. It constitutes a compromise between accepting unambiguous criteria and the possibility to differentiate methods fixed in cartographic convention.

Open access

A. Mazur and M. Cholewiński

Abstract

In the paper implementation of the factitious force concept for a controlling complex mobile manipulator has been presented. As the nonholonomic constraint only lack of longitudinal slippage of wheels has been chosen - in skid-steering platforms lateral slippage is necessary to change orientation of such a platform. From a control theory point of view such a system is dynamically underactuated. As a solution to a underactuation problem a method of factitious force has been proposed. This method assumes extension on the dynamics level, in the form of an additional control inputs uv, which values are equal to zero equivalently. For a mobile manipulator, consisting of platform REX and 5R robotic onboard arm, a cascaded control law has been proposed. A simulation study was conducted for a mathematical model of a considered object with real values of physical parameters, i.e. lengths, masses, inertia moments etc. obtained from the 3D model. Results obtained in simulations have shown a proper action of the control system and convergence of tracking errors, occurring in a platform and in joints of a manipulator, to zero.

Open access

M. Mazur, J. Domaradzki and D. Wojcieszak

Abstract

In this paper, the influence of vanadium doping on optical and electrical properties of titanium dioxide thin films has been discussed. The (Ti-V)Ox thin films was deposited on silicon and Corning glass substrates using high energy reactive magnetron sputtering process. Measurements performed with the aid of x-ray diffraction revealed, that deposited thin film was composed of nanocrystalline mixture of TiO2-anatase, V2O3 and β-V2O5 phases. The amount of vanadium in the thin film, estimated on the basis of energy dispersive spectroscopy measurement, was equal to 3 at. %. Optical properties were evaluated based on transmission and reflection measurements. (Ti-V)Ox thin film was well transparent and the absorption edge was shifted by only 11 nm towards longer wavelengths in comparison to undoped TiO2. Electrical measurements revealed, that investigated thin film was transparent oxide semiconductors with n-type electrical conduction and resistivity of about 2.7 · 105 Ωcm at room temperature. Additionally, measured I-V characteristics of TOS-Si heterostructure were nonlinear and asymmetrical.

Open access

Robert Ulewicz, Dorota Jelonek and Magdalena Mazur

Abstract

The article presents the results of analysis, the use of continuous flow of logic at the stage of production planning and control of the company producing furniture. The concept of continuous flow tends to regulate the flow of materials in a manner that provides the shortest flow path without unnecessary activities (Muda is a Japanese word meaning waste), a constant takt and defined throughput at constant resource requirements for the so-called transfer of material through the whole process. In the study Glenday’d sieve method was used to identify the correct area, which requires the value stream mapping, and areas called excessive complexity, which do not provide added value. The use of Glenday’s sieve method made it possible to identify areas in which it must be improve production capacity.

Open access

W. Pachla, A. Mazur, J. Skiba, M. Kulczyk and S. Przybysz

Effect of Hydrostatic Extrusion with Back Pressure on Mechanical Properties of Grey and Nodular Cast Irons

Cold hydrostatic extrusion with and without back pressure of ferritic-pearlitic grey cast iron EN-GJL 250 and ferritic-pearlitic nodular cast iron EN-GJS 500-7 has been performed. The experiments were performed on a originally designed hydrostatic extrusion press operating up to 2000 MPa with back pressure up to 700 MPa. Cast irons were cold hydrostatically extruded with back pressure in one pass with extrusion ratios up to 1.77 and 2.12 for grey and nodular one, respectively. Nodular cast iron was also successfully extruded without back pressure with extrusion ratio 1.35. Severe plastic deformation has led to axial alignment and elongation of graphite inclusions in extrusion direction together with sound flow of the surrounding metal matrix accommodating the strain without cracking. External high pressure has restrained of cracks generation and propagation during the material flow and healed of already existing defects by internal friction caused by plastic flow. It was visualized by aligned and elongated graphite flakes and nodules and no cracks and porosity observed in surrounded metal matrix. Very high compressive strength of both materials has been measured, above 1000 MPa and ~2400 MPa for grey and nodular cast iron, respectively. These values were accompanied by above 3000 MPa and above 3400 MPa microhardnes HV0.2 and by over 15% and over 50% elongation at maximum strength for those materials, respectively. Cast irons with such properties can be classified as a new iron-base structural materials.

Open access

W. Pachla, A. Mazur, J. Skiba, M. Kulczyk and S. Przybysz

Wrought Magnesium Alloys ZM21, ZW3 and WE43 Processed by Hydrostatic Extrusion with Back Pressure

Cold hydrostatic extrusion with and without back pressure of commercial ZM21, ZW3 and WE43 magnesium alloys has been performed at originally designed hydrostatic extrusion press operating up to 2000 MPa with back pressure up to 700 MPa. Alloys were cold extruded in one pass into rods between 5 and 9 mm in the outer diameter with product velocities between 1 and 10 m/min and extrusion ratios above 2. Application of back pressure extended formability of all magnesium alloys. It was due to hydrostatic pressure superimposed on the extruded product what inhibits the cracks generation and propagation. Cold deformation restrained the grain growth and softening processes while severe deformation in one pass increased grain refinement and density of internal defects. Ultimate tensile strength ranging from 370 MPa (ZM21) through 400 MPa (ZW3) up to 410 MPa (WE43), with respective yield stresses from 270 MPa through 300 MPa up to 350 MPa and the respective elongation from 13% through 12% to 7% were obtained in extruded rods, which are the best reported data in literature up to this day. Wrought magnesium alloys after hydrostatic extrusion can serve as semi-products for structures that call for high strength, for example as biodegradable implants or fastening components in form of bolts, rivets, nuts, pins, joints, etc.

Open access

M. Perzyk, J. Kozlowski, M. Mazur and K. Szymczewski

Abstract

Simulation software can be used not only for checking the correctness of a particular design but also for finding rules which could be used in majority of future designs. In the present work the recommendations for optimal distance between a side feeder and a casting wall were formulated. The shrinkage problems with application of side feeders may arise from overheating of the moulding sand layer between casting wall and the feeder in case the neck is too short as well as formation of a hot spot at the junction of the neck and the casting. A large number of simulations using commercial software were carried out, in which the main independent variables were: the feeder’s neck length, type and geometry of the feeder, as well as geometry and material of the casting. It was found that the shrinkage defects do not appear for tubular castings, whereas for flat walled castings the neck length and the feeders’ geometry are important parameters to be set properly in order to avoid the shrinkage defects. The rules for optimal lengths were found using the Rough Sets Theory approach, separately for traditional and exothermic feeders.

Open access

Krzysztof Kalinski, Marek Galewski and Michał Mazur

Abstract

The paper concerns development of original method of optimal control at energy performance index and its application to dynamic processes surveillance of some mechatronic systems. The latter concerns chatter vibration surveillance during highspeed slender milling of rigid details, as well as motion control of two-wheeled mobile platform. Results of on-line computer simulations and real performance on the target objects reflect a great efficiency of the processes surveillance

Open access

M. Lis, A. Wrona, J. Mazur, C. Dupont, M. Kamińska, D. Kopyto and M. Kwarciński

Abstract

The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4). The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

Open access

M. Grodzicki, P. Mazur, S. Zuber, J. Pers and A. Ciszewski

Abstract

This report concerns the properties of an interface formed between Pd films deposited onto the surface of (0001)-oriented n-type GaN at room temperature (RT) under ultrahigh vacuum. The surface of clean substrate and the stages of Pd-film growth were characterized in situ by X-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), ultraviolet photoelectron spectroscopy (UPS), and low energy electron diffraction (LEED).

As-deposited Pd films are grainy, cover the substrate surface uniformly and reproduce its topography. Electron affinity of the clean n-GaN surface amounts to 3.1 eV. The work function of the Pd-film is equal to 5.3 eV. No chemical interaction has been found at the Pd/GaN interface formed at RT. The Schottky barrier height of the Pd/GaN contact is equal to 1.60 eV.