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The study presents the influence of anti-wear coatings and the type of material from which cutting tools are made of at the cutting temperature occurring on the tool. Cutting tools made of boron nitride and tungsten carbide composite were investigated. The methodology of measuring cutting temperature using thermoelement and thermovision techniques was presented. The results of temperature measurements occurring on the cutting tool in the cutting zone were compared. The paper also presents a method to determining the effective emissivity of the tested tools necessary for correct temperature measurement using the non-contact method. The obtained data were interpreted and the relationships described, and then the results obtained were discussed.

Mobile devices and various applications have become an increasingly essential aspect of daily user activity. A key element common for mobile applications available on the market is that they use geolocation. This functionality supports desirable actions to be performed in respect of personalized user expectations. Although the functionality provides a number of benefits, it may also be a source of potential risks to its users. Not only does it expose their views but it may also limit their civil liberties. The article discusses issues related to the access to private data through geolocation services on mobile devices. It focuses on quantitative and qualitative research involving a sample of two hundred most popular free applications in Poland. Research questions aim to obtain information about the nature and the percentage of applications that require access to dubious or special permissions, implemented tracking codes, or trackers, as well as to verify the correlation between tracking codes embedded in applications and requests for access permission. The explanation of technological conditions and processes conducive to aggregate seemingly inaccessible data and possibilities of their use was essential to the success of the research.

Tailoring surface properties by layer-by-layer (LBL) deposition directed on the construction of complex multilayer coatings with nanoscale precision enables the development of novel structures and devices with desired functional properties (i.e., osseointegration, bactericidal activity, biocorrosion protection). Herein, electrostatic self-assembly was applied to fabricate biopolymer-based coatings involving chitosan (CSM) and alginate (AL) enriched with caffeic acid (CA) on Ti-6Al-7Nb alloyed surfaces. The method of CA grafting onto the chitosan backbone (CA-g-CSM) as well as all used reagents for implant functionalization were chosen as green and sustainable approach. The final procedure of surface modification of the Ti-6Al-7Nb alloy consists of three steps: (i) chemical treatment in Piranha solution, (ii) plasma chemical-activation of the Ti alloy surface in a RF CVD (Radio Frequency Chemical Vapour Deposition) reactor using Ar, O2 and NH3 gaseous precursors, and (iii) a multi-step deposition of bio-functional coatings via dip-coating method. Corrosion tests have revealed that the resulting chitosan-based coatings, also these involving CA, block the specimen surface and hinder corrosion of titanium alloy. Furthermore, the antioxidant layers are characterized by beneficial level of roughness (Ra up ca. 350 nm) and moderate hydrophilicity (59°) with the dispersion part of conducive surface energy ca. 30 mJ/m2. Noteworthy, all coatings are biocompatible as the intact morphology of cultured eukaryotic cells ensured proper growth and proliferation, while exhibit bacteriostatic character, particularly in contact with Gram-(−) bacteria (E. coli). The study indicates that the applied simple sustainable strategy has contributed significantly to obtaining homogeneous, stable, and biocompatible while antibacterial biopolymer-based coatings., This work has been supported by the National Science Centre (NCN) (grant decision no. DEC-2017/01/X/ST8/00886).

DLC:Si and DLC:N (diamond-like carbons doped with Si or N) functional layers in different configurations are deposited on polyurethane (PU) for bioengineering applications using CCP (capacitively coupled plasma) discharge generated in the PE CVD (plasma-enhanced chemical vapor deposition) system. Scanning electron microscopy (SEM) observations show that the obtained single and multilayers are continuous and well adherent to the substrates, but they differ in surface morphologies. DLC:Si layers form granular-like outer surfaces, while DLC:N ones a mosaic structure of plain areas. Topography analyses by atomic force microscopy (AFM) and optical profilometry reveal that Si-doped layers are characterized by significantly higher surface roughness (Ra ca. 5 nm) in comparison to N-doped layers (Ra ca. 0.3 nm) and also higher values of profile roughness parameter Rz (up to 32 μm vs. about 13 μm). Energy-dispersive X-ray spectroscopy (EDS) analysis indicates the homogenous chemical composition of the layers. DLC:N layers, are characterized by significantly higher polar component of surface free energy (up to ca. 5.0 mJ/m2). DLC:Si layers exhibit higher values of diiodomethane contact angle (up to ca. 90°) compared with DLC:N layers (up to ca. 55°). The attenuated total reflectance Fourier transform infrared spectroscopic measurements (ATR-FTIR) of the layers reveal that the addition of silicon to the DLC structure increases the content of terminal CHn bonds (n = 1, 2, 3) as well as beneficial Si–H and Si–CHn bonds, which significantly reduce the internal stresses in the layers. Both DLC:Si and DLC:N layers exhibit no cytotoxic effects using the human osteoblast-like cell line and human keratinocytes.

Background: Back pain syndromes are one of the most common health problems in the population of industrialized countries, including Poland. Aim of the study: The aim of the work is to show the dependence or type of work performed affects the occurrence of pain in the spine in the study group Material and methods: The research covered 90 people, including 44 whitecollar workers and 46 manual workers. The author's questionnaire and Oswestry Questionnaire were used for the research. Results: In our own research, it was noticed that 90% of patients had spinal pain. They concerned the cross and lumbar sections. It was found that men were more disabled than men. It was also reported that there is no relationship between the age of the examined persons and the level of their disability. Conclusions: It was found that the type of work performed does not affect the occurrence of spinal pain syndrome. It has been noticed, however, that it is more common for people who work

The aim of the study was to evaluate tribological properties of ultra-high-molecular-weight polyethylene (UHMWPE). This study concerns the areas of both mechanical and biomechanical application fields, including chain guides and knee or hip joint liner replacement. The presented paper describes conducted research on tribological properties of UHMWPE with tribological testing station UMT-2 Bruker. This testing station is capable of conducting tribological tests of ferrous, non-ferrous metals, plastics, ceramics, composites, and various types of coatings, under both "dry" and liquid and solid lubricating agents. Tests were performed under various conditions, differing in relative speed and the load of interacting frictional pair. Moreover, test duration and the performed number of cycles were considered.

The paper presents the results of hardness tests of aluminum alloy AW-7075 (for plastic processing) and Ni-P chemical coatings (nickel-phosphorus) which had been applied by the no-current method. Coatings of various thickness have been made and their influence on the increase of the top layer hardness has been determined, as well as the increase of the hardness of the coating and substrate system after puncturing the coating with an indenter. The purpose of the investigation was to determine the possibility of applying the Ni-P coating for selected technical applications, among others, by the selection of its optimum thickness on the hard aluminum alloy and by the determination of the deformation resistance of the top layer if the given coating.

Wood-polymer composites (WPCs) as eco-friendly materials characterized by advantageous properties are a popular alternative for conventional polymeric compositions. Even though they are widely popular and utilized in many branches of industry, some of their characteristic still remain obscure. The domain which demands better insight is tribology of wood-polymer composites. The aim of this paper was to describe the phenomena behind friction and wear of WPCs in reference to the surface topography. The object of this research were α-nucleated polypropylene-based composites filled with 0, 5, 10, 20 and 30 wt.% of wood flour. Hardness, coefficient of friction and changes of surface topography of the samples due to wear were evaluated. It was concluded that addition of the natural based filler causes an increase of the composite’s coefficient of friction.

The paper presents a method of measuring the temperature during cutting and its impact on the machining process. The influence of temperature on the intensity of the cutting tool wear cutting and durability. Shows the measuring position, the materials used and the cutting tool. We present the results of the processing parameters, during which the measurements are made. This paper presents methods for measuring the temperature of the blade using a thermocouple and methods of radiation. It lists the advantages and disadvantages of each method.

In the present work, the authors describe elaborated method of machining teeth with the use of unspecialized machine tools. In the first part of the work the need to develop such a method has been shown and the drawbacks of the known methods have been indicated. Further part of the work describes the process of mathematical modelling the purpose of which was to determine the tool paths during machining. Next, the kinetics of teeth machining with the use of a universal CNC milling centre is presented. Further on, the operation of the algorithm, the user’s interface of the elaborated software and the parameters influencing the machining process have been shown. In the final part of the work, the results of examination of the obtained details have been shown on a gear wheel as an example. The origin of machining errors and their significance has been discussed. In conclusions, summary of obtained results is presented. In last paragraphs, authors discuss machining accuracy of developed method, and application possibilities of described method are emphasised as well. Performed verification proved that developed method is capable of machining gears of quality comparable with these machined with specialised equipment.

In this paper, characterization of shape and dimensional accuracy of polygons manufactured by polygonal turning were investigated. The theoretical value of maximum value of outline error was calculated and compared with real sample shape deviation. The data obtained from geometrical measurement of manufactured samples, geometrical characteristics, allowed to evaluate the influence of cutting parameters on machined part accuracy.

In this paper, information about the durability of friction clutches under high heat conditions was described. As a way to extend their life and performance, thermal spray coating method is proposed. Process of modeling and conducting simulation in FEA (finite element analysis) environment was described. The thermal stress distribution in coating system in relation to the thickness of applied coating was investigated. Conducted simulation allowed to obtain data that presented strong correlation between coating thickness and both maximum value of Huber-Mises reduced stress and stress distribution characteristics within coating. Collected data allowed to evaluate the possibility of application of such coating on an aluminum plain clutch plate that works under high heat and dry conditions. Presented research has proven that design of such coating should especially cosnider coating thickness and thermal stress condiitons, as these factors may have strong influence on relibilty of cluth plates.

The subject of this paper is the simulation study into the improvement of the production process of floorboard middle layer. The object of our interest in the manufacturing process of wooden floorboard which consists of three layers: lower—made of softwood pieces glued together; middle—in a form a module, made of softwood slats and plywood, and hardwood upper layer. The process improvement involved a better use of raw materials in the form of plats (of variable dimension groups) by reducing losses caused by defects such as wane and knots. A simulation model of the manufacturing process was created by using DES software. Thanks to that model, buffers size and a performance of the designed systems including their anticipated breakdowns were estimated. As a result of the study, a concept of the entire production system meeting the requested production capacity and material efficiency was devised.

State of art in the field of wear resistance indicate that, coatings produced with thermal spray methods, can significantly contribute to increase wear rate under conditions of wide range of sliding speeds and varying temperature values. In the beginning of this paper mechanical properties, manufacturing technology and possible applications of thermal sprayed coatings were reviewed. Mechanical properties for selected MMC (metal-matrix composites) materials applied for such coatings were introduced. Determining both stress and deformations of HVOF anti-wear coatings was necessary in order to estimate possible use of these coatings in application on machine parts exposed to high contact pressure and increased temperature. As well, relationship between different materials participation and mechanical properties of produced coatings were mentioned. Analysis method, model and boundary conditions were stated as method of experiment. Numerous structural FEM analysis were performed in order to determine stress and deformations in model samples under conditions of contact pressure and thermal conditions. High temperature was applied in prepared simulations to verify stress and deformation of samples caused by difference in base material and coating coefficient of thermal expansion. 3D structural simulations were conducted, in order to verify stress in different sections. Finite elements size and shape were optimized for obtaining possible short time of both mesh generation and solving of numerical problems. Contact pressure conditions were assumed as same for all simulations, for increasing result comparison possibilities. Analyses were performed for different geometry of samples, differing in coating thickness and surface curvature. Simulations of coatings on both round and flat surfaces were conducted in order to designate influence of surface curvature on coating stress under conditions of contact pressure and high temperature. Results of performed simulations were presented, including detailed information about stress in various direction, deformations and shear stress in area between base material and coating. Correlations between results and geometrical parameters of model were presented, especially including curvature and thickens of coating. Discussion of obtained results and recorded correlations was presented in last paragraphs of this paper. Authors find obtained results as useful initial data in further research on field of thermal sprayed coating application on machine parts exposed to high contact pressures.

Results of tribological tests of Ni-P coating were presented in following paper. Tests were conducted with tribotester device using linear reciprocating wear test. Tribological wear test conditions, especially speed, load and sample geometry were described. Characteristics of coefficient of friction variation during wear testes were recorded. Conclusions included results interpretation especially focusing on influence of coating thickness in its properties.

In the paper, a numerical study of the size of representative volume element for the linear elasticity problem is performed. The calculations are carried out for three different types of random microstructures: checkerboard, the Ising model microstructure and Debye microstructure. It is postulated and then verified that there exists a relation between the morphology of microstructure contained in the lineal-path function and the minimum RVE size. It is confirmed, on the basis of numerical examples, that for all the microstructures considered the largest lineal-path can be treated as the size of RVE

This paper describes measurement methods of temperature machining with WCCo-cBN composite cutting tools. Both contact and thermographic methods of cutting temperature measurements have been described and compared. As well, methodology of emissivity evaluation of cutting tools materials has been mentioned. This paper also covers influence of antiwear TiAlN PVD coating on cutting temperature in reference to machining with uncoated tools.

This paper describes process of kinematics modelling for new method of gears cutting with milling center. Need for usage of mufti-purpose machines and tools in gear cutting is described. Known methods of gear cutting with machining centers are presented. Disadvantages and problem with known methods are introduced, as well need for new method is mentioned. Preparation of kinematical model of new method of gear cutting is followed by estimation of theoretical roughness of tooth flank. In last paragraphs requirements for machines and tools prepared for application of this method are discussed, as well technological characteristics of this method is presented.

Recent advances in surface engineering and solid lubrication technologies offer unique possibilities for better controlling friction and wear under boundary or marginally lubricated rolling, sliding or rotating contact conditions. The aim of the study was to evaluate influence of graphite solid lubrication addition on silicone oil tribological performance. Studies of graphite solid lubrication effect was carried out with using tribological testing station UMT-2 Bruker. Tests were performed against UHMW polyethylene samples and under various conditions, differing in relative speed and the load of interacting frictional pair.

Artykuł ma na celu przybliżenie teorii duopolu w ekonomii oraz przedstawienie zmian, jakie zaszły na rynku czynników chłodzących wykorzystywanych w urządzeniach klimatyzacyjnych wskutek wprowadzenia unijnej dyrektywy 2006/40/EG. The paper aims is to explain the theory of duopoly in economics and show the changes that have taken place in the market of refrigerants used in air conditioning after the implementation of the EU Directive 2006/40/EG. Udostępnienie publikacji Wydawnictwa Uniwersytetu Łódzkiego finansowane w ramach projektu „Doskonałość naukowa kluczem do doskonałości kształcenia”. Projekt realizowany jest ze środków Europejskiego Funduszu Społecznego w ramach Programu Operacyjnego Wiedza Edukacja Rozwój; nr umowy: POWER.03.05.00-00-Z092/17-00.

Since 2008, it has been recognised by most health authorities worldwide that the abuse of newly-emerging psychoactive drugs, ('designer drugs'/'legal highs'; DD), in youth is a rapidly increasing problem, especially in the EU, threatening to offset gains made in tackling established and illegal drugs which they are intended to mimic; DD diversity is continually increasing to circumvent laws. The aim of the study was to determine the scale of DD abuse/availability amongst Polish youth. The surveyed test population was randomly selected from a representative group of adolescents attending high schools, secondary schools and universities throughout Poland. Questionnaires were completed by 14,511 subjects (10,083 school pupils and 4,428 students). Few persons from each group admitted using DDs; 453 school pupils (4.49%) vs. 81 students (1.83%). More males (4.74%) took DDs than females (2.77%). The tendency to take DDs in the company of friends was high in both DD-taking groups (80%). DDs were consumed mostly in open spaces (34.15%), discos/pubs (21.13%) and boarding school/friend's house (20.57). Most frequently, DDs came from shops (57.68%), friends (31.46%) or dealers (10.11%). Ensuing symptoms included; happy/euphoric mood (58.80%), talkativeness (42.51%) and hallucinations (22.85%). Over 74% of DD-takers in both groups experienced adverse reactions, and those requiring help sought it from: friends/colleagues (6.74%), doctors (5.06%), and hospitals (4.87%), but most rarely from parents/guardians (2.62%). Urgent action is being taken, especially in youth education, to prevent DDs becoming the serious menace seen with conventional drugs.

Differences between modern pollen rains in three types of phytocoenoses were studied in two regions, i.e. Tuchola Forest and Torun Basin. The phytocoenoses in question were heaths, young pine-birch growths and mature pine tree stands, which form a temporal sequence and spatial mosaic in the landscape. In order to compare the structure of pollen samples, phytocoenoses and the landscape, the methods of numerical taxonomy were applied. An increase in the average number of sporomorphs was recorded, as well as in the taxonomic diversity of the pollen spectrum in this temporal sequence arranged from non-forest communities through young growths to mature forests. In the subsequent developmental stages, also the percentage contribution of Pinus pollen increased, as well as the total contribution of arboreal pollen (AP). The increase in the percentage contribution of arboreal pollen is accompanied by the decrease in the contribution of non-arboreal pollen (NAP), including Calluna and Ericaceae. Also a small increase in the number of species was observed. With the increased pine domination, however, the diversity of pollen types (expressed by rarefaction and Shannon-Wiener indices) decreases. As a result of the performed analyses, it was also found that the species composition of phytocoenoses and a pollen spectrum differs considerably, because the import of pollen from further areas exerts a significant influence on the structure of a palynological sample. The genus Calluna is the only type of plants characterized by a strong relationship between the occurrence in a phytocoenosis and in a surface pollen sample. Similarity between the taxa composition of a pollen spectrum and the landscape structure , consisting of a mosaic of phytocoenoses , seems to be higher than between a pollen sample and a phytocoenosis from which that sample was collected. The latter thesis, however, needs to be confirmed by further researches.

In this paper we present a theoretical framework for novelty based feedback regulation in artificial neural networks. Novelty is assessed on the basis of monitoring the coherence of network dynamics. The result of novelty detection is dynamically coupled to parameters that control the dynamics of the recognition process. The paper presents a new measure of novelty detection--the strength of the local field--and presents new simulation results concerning novelty detection. It also integrates previously published models and simulation results into a general dynamical model of feedback regulation.