bluuebunny/crossref_metadata_2025 huggingface dataset:
The first Polish provenance experiments with silver fir Abies alba Mill.
Authors: Gunia Stanisław , Łukaszewicz Jan , Szeligowski Henryk
Published: June 2020

Silver fir Abies alba Mill. provenance trials started in Poland a few years after Pavari (1951) proved that the origin of this tree species influences its genetic variability. Further confirmation came from provenance trials, which selected provenances for cultivation in Denmark and showed provenance-dependent genetic variability even within a relatively small area such as the Czech Republic. The Polish trial, started in 1960, compared 6 provenances from the West and Central Carpathian region (4 from Poland, 2 from Slovakia) and 3 from the Hercinic region (Czech Republic). The trial was established in the Experimental Forests of the Warsaw University of Life Sciences in Rogów, at the northern border of the natural silver fir range. Results from the nursery stage experiments proved the existence of latitudinal and altitudinal clines based on data for seed weight, height growth, number of terminal buds as well as bud and needle development. The Polish provenance ‘Stary Sącz’ and two Slovak provenances, ‘Čierný Váh’ and ‘Beňuš’, were early flushing, whereas the Polish provenance ‘Rogów’ behaved differently and was late flushing. Even at the nursery stage, the positive influence of tree selection on height growth and progeny characteristics of the two Czech provenances was evident. The Carpathian provenances were furthermore evaluated according to the index of cultivation and breeding: very good – ‘Rogów’; good ‘ŚPN (Świętokrzyski PN)’, ‘Stary Sącz’ and ‘Skarżysko’; poor – ‘Čierný Váh’ and ‘Beňuš’.
Evaluating the suitability of machinery use during skidding of wood in pine stands
Authors: Szewczyk Katarzyna , Iwanicki Piotr
Published: June 2020

Skidding of large-sized logs requires special machinery such as skidders, clambunks, forwarders or farm tractors with a winch or hydraulic tongs. The precise choice of which skidding machine to use depends largely on the desired efficiency and economic factors. The aim of this research was to evaluate the suitability of three different machines (LKT 81 skidder, John Deere 1110D forwarder and Pronar 1221A agricultural tractor with hydraulic tongs) for wood skidding based on technical and economic indicators. The practical work for this research was carried out in the Mirosławiec Forest Division in areas with fresh mixed coniferous forest habitats where the dominant species in the stands was pine and strip-like clear cutting was the preferred management practice.

The best machinery performance values were obtained for skidding using the John Deere forwarder.
Biochemical and histopathological effects of sub-acute exposure of albino rats to fumigants – dichlorvos and cypermethrin
Authors: Nwankwo Raphael Chukwunonso , Ibegbu Madu Daniel , Onyekwelu Kenechukwu Chibuike , Ejezie Chioma Sandra , Ikekpeazu Joy Ebele , Ejezie Fidelis Ebele
Published: June 2020

Cypermethrin (CYP) is one of the most common active ingredients in most insecticides, mosquito coils and powder used in Nigeria. dichlorvos (DDVP) is the most indiscriminately used fumigant in most rural and sub-urban areas in Nigeria. These fumigants can easily be accessed without proper method of usage thus exposing the population to their toxic effects. As a result, this study was initiated to determine the effects of sub-acute exposure of CYP and DDVP on some biochemical and histopathological parameters of albino rats. In this study, forty (40) albino rats of 10 groups of 4 rats per group, with one group serving as control, were exposed to these fumigants in a poorly ventilated area for 4hours per day over 2, 4 and 6 weeks. The results showed observable changes in liver enzyme activities (p<0.05) in groups exposed to DDVP for 2, 4 and 6 weeks. The groups exposed to CYP showed mild changes in liver enzyme activities when compared with the DDVP groups. Increase in activity of the liver enzymes was also observed in the groups exposed to a mixture of DDVP+CYP for 2, 4 and 6 weeks. The urea, creatinine and electrolytes levels in all the groups exposed to DDVP, CYP and DDVP+CYP for 2, 4 and 6weeks were significantly (p<0.05) increased. Also WBC and platelets in all the groups exposed to DDVP and CYP recorded significant changes. The histology report of the lungs and liver showed moderate lymphocytic infiltration and hepatocytic steatosis which progressed with duration of exposure to the fumigants, while the kidneys showed no remarkable changes. The results of this study suggest that DDVP and CYP have relative toxic effects in the exposed animals and should be used with caution to avoid human exposure to their visible toxicities.
The effect of venlafaxine on blood pressure and ECG in rats fed with high-fat-fructose diet
Authors: Sasváriová Michaela , Micháliková Dominika , Tyukos Kaprinay Barbara , Salvaras Lazaros , Hričáková Slavomila , Knezl Vladimír , Gáspárová Zdenka , Stankovičová Tatiana
Published: June 2020

Metabolic syndrome represents one of the major health, social and economic issues nowadays, and affects more than 25% people worldwide. Being a multifactorial health problem, metabolic syndrome clusters various features, such as obesity, dyslipidemia, hyperglycemia and hypertension. Each of these disturbances represents a risk factor for developing cardiovascular disease. Moreover, patients with metabolic syndrome are more likely to suffer from depression, thus treatment with antidepressants (e.g. venlafaxine) is often neccessary. However, many of the antidepressants themselves may contribute to worsening or even development of the metabolic syndrome, thus creating a “vicious circle”. The aim of this work was to investigate on the animal model of metabolic syndrome, i.e. on hypertriacylglycerolemic rats fed high-fat-fructose diet (HFFD): 1) the effect of a change in diet from HFFD to a standard diet (SD) and the effect of venlafaxine treatment, 2) during HFFD, 3) as well as during a changed diet to SD. We focused on biometric parameters, blood pressure and selected ECG parameters. We observed the reversibility of the present metabolic and cardiovascular changes by switching the HFFD to SD in the last 3 weeks of the experiment. Switch to the standard diet led to decrease of body weight, even in the presence of venlafaxine. Administration of venlafaxine caused the decrease of heart weight/body weight index in rats fed with HFFD compared to the untreated group fed with HFFD for 8 weeks. Blood pressure, which was increased in the HFFD group showed a tendency to decrease to control values after switching to the standard diet. Administration of venlafaxine led to significant increase in all parameters of blood pressure when rats were fed with HFFD throughout the whole experiment. In untreated rats fed with HFFD for 8 weeks, we observed a shorter PQ interval and prolonged QRS complex as well as QTc interval compared to untreated rats with diet switched to SD. This effect was potentiated by venlafaxine administered not only during HFFD but even after switch to SD. Our results point to the fact that metabolic syndrome is clearly affecting the function of the cardiovascular system by modifying blood pressure and electrical activity of the heart. Moreover, administration of venlafaxine may lead to worsening of the observed changes, especially in the presence of high-fat-fructose diet.
Dynamic tendencies in natural Slovak orthography
Authors: Rusinková Jaroslava
Published: June 2020

Nowadays we can observe changes in the use of literary Slovak, or, to be more precise, in the orthographic standard. These changes result from the language practice associated with promoting natural Slovak language. Natural Slovak language develops in oral and written form. The current codification of the literary language must deal with the emergence of different language usages in different spheres of communication.
Sociostylistics as a part of interactive stylistics – getting back and perspectives
Authors: Slančová Daniela
Published: June 2020

The article deals with the concept of interactive stylistics and sociostylistics as one of its subdisciplines. The interactive stylistics is explained as a transdisciplinary field of knowledge. In a way, the article is also a reaction to the stylistic views of Ján Bosák from the 1990s. The concept of interactive stylistics is incorporated in the trends of the Slovak stylistics in the 21stcentury. The article explains the crucial terms: interaction, communication, style, stylistic/style quality, styleme, axiological competence, principles that conduct, coordinate and control the process of stylization. Style is defined as the mode of verbal interaction which in a specific communication act acquires the qualitative value. It has a processual character. Styleme is a cognitive-pragmatic unit of the stylistic/style quality defined by its content, the inner and outer form and function. The paper presents a division of the theoretical stylistics into its subdisciplines and their research fields. Sociostylistics is divided into macro- and microsociostylistics. The concepts of macrosocial and microsocial communication registers and stratification of Slovak language are explained as the key concepts, which, stylistically understood, are the main areas of interest of sociostylistics.
Mechanical Properties of AW-5083 Alloy Joints Welded By Hybrid Method – FSW and MIG
Authors: Dudzik Krzysztof
Published: June 2020

The article presents the research results on the mechanical properties of aluminum alloy AW-5083 and its joints welded by hybrid method – traditional MIG and FSW. AW-5083 alloy is the most currently used in shipbuilding industry. Friction Stir Welding (FSW) – a new technology can be successfully used for butt-welding of different types of aluminum alloy sheets. FSW method can be an alternative to traditional arc welding methods i.e. MIG or TIG. Hybrid welding (FSW with MIG or TIG) could be used in cases when joining only by FSW is not possible. Welding parameters used for the connection of the sheets were presented. Metallographic analysis showed the correct construction of structural bonded joints. The research was carried out using a static tensile test in accordance with the requirements of the Standard PN-EN ISO 4136:2013-05. Flat samples cut perpendicular to the direction of rolling were used. The research was conducted at the temperature of +20ºC. The test shows that the mechanical properties of joints made by hybrid method compered to native material were lower. The tensile strength of joint was lower by 20% then native material 5083 while its yield stress was lower only about 6%. The biggest change was observed in case of plastic properties. Elongation of joint was over 50% lower compared to native material. Despite the decrease of mechanical properties, they meets the requirements of classification societies, so the conclusion is that hybrid method (FSW and MIG) of joining AW-5083 can be applied in shipbuilding industry.
Comparative Preliminary Unit Costs Analysis of the Operation of Passenger Cars with Combustion Engines and Fuel Cell Vehicles Powered by Hydrogen
Authors: Gis Wojciech , Waśkiewicz Jerzy , Menes Maciej , Gis Maciej
Published: June 2020

The article presents political and legal aspects regarding the recommendation for the development of hydrogen technology in the economy and in transport. The development of electric cars with hydrogen-powered fuel cells, which took place in recent years in the world, has been outlined. The principles of calculation of average vehicle operating costs applicable in the transport economics are discussed. The estimated average unit operating costs of a statistical passenger car using conventional energy carriers, estimated in the studies of the Motor Transport Institute are quoted. The assumptions and results of the estimation of the average cost per 1 vehicle-kilometre of the electric passenger car’s mileage (BEV) have been presented, as well as the assumptions and results of the estimation of the average unit operating costs of a hydrogen powered passenger car (FCEV). The average unit costs of the mileage of these vehicles have been compared. The predictions regarding the future changes in the average prices of FCEV vehicles have been cited and the average unit costs of operating electric cars with fuel cells by the 2050 have been estimated. The project of administrative support for the development of low-emission transport in Poland was indicated.
Self-Learning Control Algorithms Used to Manage the Operating of an Internal Combustion Engine
Authors: Graba Mariusz , Mamala Jarosław , Bieniek Andrzej
Published: June 2020

The article presents the possibility of using self-learning control algorithms to manage subassemblies of an internal combustion engine in order to reduce exhaust emissions to the natural environment. In compression ignition (CI) engines, the issue of emissions mainly concerns two components: particulate matter (PM) and nitrogen oxides (NOx). The work focuses mainly on the possibility of reducing the emission of nitrogen oxides. It is assumed that the particularly problematic points when it comes to excessive emission of harmful substances are the dynamic states in which combustion engines operate constantly. In dynamically changing operating points, it is very difficult to choose the right setting of actuators such as the exhaust gas recirculation (EGR) valve to ensure the correct operation of the unit and the minimum emission of these substances. In the light of the above, an attempt was made to develop a self-learning mathematical model, which can predict estimated emission levels of selected substance basing on current measurement signals (e.g. air, pressure, crankshaft rotational speed, etc.). The article presents the results of the estimation of nitrogen oxides by the trained neural network in comparison to the values measured with the use of a sensor installed in the exhaust system. The presented levels of estimated and measured results are very similar to each other and shifted over time in favour of neural networks, where the information about the emission level appears much earlier. On the basis of the estimated level, it shall be possible to make an appropriate decision about specific settings of recirculation system components, such as the EGR valve. It is estimated that by using the chosen control method it is possible significantly to reduce the emission of harmful substances into the natural environment while maintaining dynamic properties of the engine.
Determination of Material Characteristics Necessary for Modelling of Marine Structures Exposed to Small-Calibre Bullet
Authors: Kiciński Radosław , Szturomski Bogdan , Jurczak Wojciech
Published: June 2020

The article presents the results of tests of impact properties of steel 1.3964 used on the construction of modern mine destroyers. Ships of this type, like any other military unit, may be exposed to small-calibre projectiles. Firing can be done, for example, from aircraft, drones or pirate units. The thickness of the plates used in the ship’s construction does not guarantee effective resistance to the projectile calibre 7.62 mm for all compartments of such ships. Thus, it is possible to modify the existing structure or apply additional solutions that will ensure a certain level of ballistic resistance. Solutions of this type are necessary in order to maintain the stability and buoyancy of the ship at the current level. During the tests, a stress-strain curve for steel 1.3964 was obtained, then the Johnson-Cook plasticity and damage model was proposed, which was used in the FEM simulation. The task was modelled as non-linear considering the deformation of both the sample and the projectile. The simulation was prepared in the CAE program, and then verified by an experiment on the shooting range. The results were presented in the form of diagrams and deformation figures, and were compared with photographs of samples and velocities after the specimen.
Influence of Inlet Geometry on the Efficiency of 1 MW Steam Turbine
Authors: Koprowski Arkadusz , Gotowski Dominik , Rzadkowski Romuald , Szczepanik Ryszard
Published: June 2020

The process of the design of the 1 MW steam turbine includes designing the stator and rotor blades, the steam turbine inlet and exit, the casing and the rotor. A turbine that operates at rotation speeds other than 3000 rpm requires a gearbox and generator with complex electronic software. This article analyses the efficiency of eight turbine variants, including seven inlet geometries and three stages of stator as well as an eight variant with one of the inlets, all three stages and an outlet.

This article analyses the efficiency of 8 turbine variants, including four spiral inlet geometries and tree stages in a 1 MW steam turbine. In the article, inlets and 1st stator blades of various geometries were analysed to obtain maximal turbine efficiency. Changing the inlet spiral from one pipe to two pipes increased the turbine efficiency. The geometry of the blades and turbine inlets and outlet was carried out using Design Modeller. The blade mesh was prepared in TurboGrid and inlet in ANSYS Meshing.
Technical and Ecological Analysis of Different Solutions of the Power Supply of a Marine Diesel Engine
Authors: Krakowski Rafał
Published: June 2020

The article contains provisions on the prevention of sea pollution by ships, including, inter alia, the International Convention for the Prevention of Pollution from Ships, developed in 1973 (MARPOL). The convention aims to protect the marine environment from oil and its derivatives. Special areas, where extraordinary measures have been taken to prevent sea pollution, due to the intensity of ship traffic and the greater threat of damage to the marine environment have also been presented. In the further part of the article, the applicability of various pro-ecological solutions, i.e. the use of catalysts, low-sulphur fuels, and in the case of using residual fuels – exhaust gas scrubbers were described. In the main part of the article, a technical and ecological analysis was made. In addition, difficulties resulting from the use of pro-ecological solutions were described. The costs of using low-sulphur fuel meeting the emission standards, installing the scrubber and modification of the natural gas combustion unit were compared with the assumption of ten years of passenger-car ferry sailing. Then the problems that individual solutions create were shown. In the final part of the article, alternatives to those described, i.e. the liquefied natural gas (LNG) power supply, electric and hydrogen drives were presented.
Composite Materials for Warship Constructions
Authors: Kyzioł Lesław
Published: June 2020

The article presents the basic properties of composite materials used for the construction of special ships. Static and dynamic characteristics of materials such as wood and polyester-glass composites are presented. Noteworthy are materials such as surface modified wood and polyester-glass composites with the addition of recyclate. Composite materials are widely used materials for the construction of non-magnetic warships. The article describes the properties of surface modified wood with polymethyl methacrylate and a polyester-glass composite with the addition of recyclate. The recyclate is fragmented, milled polyester-glass scrap. The content of the recyclate greatly affects the mechanical properties of the composite. The properties of the composite with the addition of recyclate depend on the recyclate content as well as the production technology and size of the recycled granulates. The test results showed that the increase in the recycled content causes a decrease in the mechanical properties of the composite. However, it should be remembered that these materials originated from waste, waste that is not subject to self-degradation, which have a very negative impact on the natural environment. At present, where there is a very large pollution of the natural environment, the processing and management of huge amounts of composite waste is an essential goal. A significant amount of recyclate significantly reduces the mechanical properties of the composite; however, the same large amount of recycled material has been transformed and used. The manufactured material and its structural elements are still non-magnetic structures and can be used on a less loaded element. The choice of material for the construction of special ships elements is determined not only by its properties but also by knowledge, experience, method of processing, economic and technical risk.
Comparative Analysis of Fuels Derived from PE Plastic Waste with a Mixture of Plastic Recycling Waste of Codes: 1, 2, 4, 5, 6 and 7 Based on Low-Temperature Pyrolysis
Authors: Lesnau Anna , Tyliszczak Mirosław
Published: June 2020

Thanks to their numerous advantages, plastics are becoming more and more widely used in all branches of industry. The quantities of products, their packaging and, consequently, the amount of synthetic polymer waste are steadily increasing, what poses a high risk to the environment due to their long decomposition time. To reduce waste production is practically impossible, therefore it is very important to constantly implement new and improve existing methods of waste treatment. The following article presents one of the alternative methods for synthetic polymer waste treatment, which is low-temperature pyrolysis. Two pyrolysis processes were carried out. During the first experiment a polyethylene plastic material was used, in the second experiment a mixture of typical household recycling waste of codes 1, 2, 4, 5, 6, and 7 were tested. During the thermal processing, the input material undergoes a chemical transformation due to breaking of long hydrocarbon chains. At the same time, high-energy density products, such as petroleum products and gas, are produced. The main advantage of the presented method is that it allows reducing preliminary technological processes to a minimum and it is easily automated, as it reduces the process to one compact installation. The reduction of the amount of stored waste and the recovery of petroleum derivatives, are additional advantages of pyrolysis implementation. That, in consequence allows reducing consumption of fossil fuel resources.
Application of Similarity Method of Distance Courses Describing the Elements Content in Cement Concrete After 50 Forced Thermal Cycles
Authors: Linek Małgorzata
Published: June 2020

The article presents material solution based on the application of ceramic dust as concrete mix component intended for airfield pavements. The applied dust influences the changes in internal structure of concrete composite. Diversification of internal microstructure of cement concrete using the suggested dust has significant influence on the improvement of compressive strength. The laboratory analyses included concretes curing in standard conditions and concretes subject to thermal cycles representing the destructive influence of imposed loading. Comparative SEM observations of concretes subject to 50 thermal cycles proved significant influence of dust on internal structure of composite. In the study 6 samples were selected, which, each time, were intended for the laboratory tests. The applied similarity analysis of distance courses in case of this concrete. Similarity indexes between input and target sequence were defined. Diagrams presenting the similarity of the analysed concretes were prepared (after 28 days of curing and after 50 thermal cycles). It was proved that the suggested method can be used to assess the elements content and define the similarity of concrete intended for airfield pavements in the selected of areas (cement matrix, contact area between fine aggregate and cement matrix, contact area between coarse aggregate and cement matrix and contact area between air voids and cement matrix).
The Experimental Investigation of Surface Roughness After Dry Turning of Steel S235
Authors: Molenda Justyna
Published: June 2020

Nowadays lot of scientific work inspired by industry companies was done with the aim to avoid the use of cutting fluids in machining operations. The reasons were ecological and human health problems caused by the cutting fluid. The most logical solution, which can be taken to eliminate all of the problems associated with the use of cooling lubricant, is dry machining. In most cases, however, a machining operation without lubricant finds acceptance only when it is possible to guarantee that the part quality and machining times achieved in wet machining are equalled or surpassed. Surface finish has become an important indicator of quality and precision in manufacturing processes and it is considered as one of the most important parameter in industry. Today the quality of surface finish is a significant requirement for many workpieces. Thus, the choice of optimized cutting parameters is very important for controlling the required surface quality. In the present study, the influence of different machining parameters on surface roughness has been analysed. Experiments were conducted for turning, as it is the most frequently used machining process in machine industry. All these parameters have been studied in terms of depth of cut (ap), feed rate (f) and cutting speed (vc). As workpiece, material steel S235 has been selected. This work presents results of research done during turning realised on conventional lathe CDS 6250 BX-1000 with severe parameters. These demonstrate the necessity of further, more detailed research on turning process results.
Numerical Investigation of Endplates Influence on the Wing in Ground Effect Lift Force
Authors: Rojewski Adam , Bartoszewicz Jarosław
Published: June 2020

The article presents a comparison of the wing in ground effect magnitude of conceptual WIG craft model main characteristics for a wing with and without endplates which are also known as winglets in regular aircraft. In article, the author describes WIG effect with and WIG craft, which operates on low altitude, smaller than the length of wing chord, mostly above the water reservoir. WIG effect phenomenon is simple. The first aircraft needs to fly at adequate altitude, with a smaller distance between lower airfoil surface and ground static pressure rises, leading to rising of lift force. The main advantage of the wing in ground effect craft on regular aircraft is a much higher lift to drag ratio, also this phenomenon provides to drop in specific fuel consumption of aircraft and allows flying with heavier cargo due to higher lift force. Characteristics present in the article were designated from simulations, which were conducted in Ansys Fluent software. Results obtained for a wing with endplate in numerical analysis shows the superiority of this approach. Endplates provide to increase WIG effect by a decrease in induced drag through the move out vertices from the wing tips, which are made by differential pressure above and under the wing. As winglets in regular aircraft, endplates provide to save fuel. WIG craft does not need airports so it could be a cheap alternative for modern aircraft.
Analysis of the Vehicle Exploitation Process with Regard to Profiling
Authors: Siergiejczyk Mirosław , Rosiński Adam
Published: June 2020

Transport telematics systems integrate information technology with telecommunications for their use in various transport systems. Thanks to the use of advanced technical solutions and modern telecommunications and IT systems, it is possible to implement additional innovative services. They can be used to rationalize the process of using and maintaining means of transport. Modern vehicles are equipped with telematic on-board systems. Such solutions combine various electronic devices used in the vehicle. For this purpose, bus solutions are used, thanks to which it is possible to control individual systems and devices. It is also possible to use the transmitted data to detect negative exploitation phenomena during vehicle use (e.g. glazing phenomenon, work in the upper engine rev range with too low coolant temperature, intensive work compressor of the high air pressure system being a symptom of inability of pneumatic systems). This is possible because the data being sent has a specific information resource. Thanks to this, to can be concluded about the loss of the exploitation potential of the vehicle. This approach will be used to rationalize the technical service of the vehicle fleet, with regard to profiling. Using exploitation data, received via a telematic interface from vehicles, it is possible to profile the rolling stock. It consists in distinguishing individual sets of vehicles due to certain reliability and exploitation properties. This approach allows for the specification of the rolling stock exploitation, giving the opportunity to rationalize the use and exploitation. The publication presents the author’s graph of the exploitation process taking into account the profiling of the vehicle fleet. The application of the presented approach will contribute to the improvement of the value of certain vehicle reliability and exploitation indicators.
Anomaly of Rotor Dynamics in Ultra-Light Helicopter – Robinson R22
Authors: Sobieszek Agnieszka
Published: June 2020

The article presents the analysis of anomaly of rotor dynamics in ultra-light helicopter - Robinson R22. Robinson R22 is two-seat, two-blade main rotor and single-engine helicopter, well known as simple and common used aircraft because of low price and high availability. At the same time, large number of accidents and strictly defined rules (recommended piloting technique) and weather condition for safe flight show disadvantages of Robinson R22. The reason for considering this topic is the analysis of different flight properties and helicopter behaviour as well as easy entering into dangerous flight manoeuvre. In the article different flight properties and loss of control during the pull-up, manoeuvre or vertical gusts of wind and mast bumping accidents were analysed. Analysis shows that problem may be caused by construction of three-hinged rotor hub, designed and patented by F. Robinson. Article presents model of rotor hub and review of main rotor and rotor hub construction in light helicopters. Because of number of accidents, caused by the unusual behaviour of Robinson R22, restrictive pilotage rules were introduced: prohibition of flight in certain weather conditions, the necessity of attending additional training conducted by trained instructors. To reduce the probability of an accident a special instruction for specific Robinson R22 properties was created. Moreover, the statistics of accidents resulting from loss of control and review of legal changes caused by Robinson R22 accidents are presented.
Introduction to the Examination of Thin-Walled Structures Using the Vibrodiagnostic Method
Authors: Szeleziński Adam , Muc Adam , Murawski Lech , Van Doan Do
Published: June 2020

The article presents a methodology of non-destructive diagnostic vibratory tests of welded plates with geometrical parameters that classify them into a group of thin-walled panels. On the basis of such plates, most ship constructions are created. In previous works, the authors dealt with the study of welded joints in plates with significant thicknesses and developed for them a number of methods for assessing the quality of welded joints. Vibrodiagnostics is a NDT method that allows the use of a variety of techniques and tools. It enables measurements to be made in both a contact and non-contact way depending on the requirements of the structure and the environment. Vibrodiagnostic method is one of the most modern NDT methods, which uses modern measurement tools and computer analysis of data. On the basis of the developed methods, the authors intend to verify their application to plates from real welded constructions, which will be performed in typical shipyard conditions by welders. Such tests are important due to their use for the construction of a real SHM ship construction monitoring system. These methods allow for the examination of the condition of ships’ structural plates and can detect defects in welded joints that prevent ships from operating under severe sea conditions. The article presents the laboratory stand, the sensor layout, results, and their initial analysis.
Numerical Investigations of Stress Concentration in Reinforcement Steel Structure by Composite Overlays
Authors: Szybiński Bogdan , Wygoda Mateusz
Published: June 2020

The stress concentration observed in the vicinity of cut-outs and holes in structural elements significantly influences the fatigue endurance of machines subjected to cyclic loads. Numerous studies have been made so far to improve this situation and increase the structure lifetime. Several design recommendations have also been worked out to avoid the problem of premature failure. The proposed article illustrates the influence of the composite overlays applied around the cut-outs made in flat steel constructional elements subjected to axial tension. The detailed study concerns the reinforcement made from the FRP (fibre reinforcement polymer) composite applied around the notches. Two types of composite materials were used, namely: TVR 380 M12/R-glass (glass fibres embedded in epoxy resin matrix) and AS4D/9310 (carbon fibres embedded in epoxy resin matrix). In the first step, the detailed numerical studies (finite element analysis) were performed for the steel samples (with no overlays added) with cut-outs made in the form of circle, square and triangle hole (the last two with rounded corners). The results of these studies were compared with the existing analytical solutions with respect to the stress concentration factors (SCF) estimation. The relatively good conformity was observed when using dense meshes of finite elements placed around the void vicinity. In the next step, the composite overlays were applied around cut-outs and their influence on the stress concentration was investigated. The influence of the fibre orientation, numbers of layers, sizes of the composite overlay used were considered. It was proved that the application of composite overlays evidently decreases the stress concentration around the notches.
Analysis of Possibility of Repairing Welding of Selected of the Steam Turbines
Authors: Wieczorska Agata , Bujko Adrian
Published: June 2020

The article presents the results of the study on the possibilities of repair by welding methods of exploitation steam turbine bodies. Two hull were investigation after a lifetime of more than 200.000 hours. Repair welding study were carried out on the L17HMF cast steel body in the immediately after exploitation condition, whereas the L21HMF cast steel body underwent a revitalization after the exploitation, and then the welding repair research were performed. On the material taken from the L17HMF cast steel hull, welding repairs were made by welding the previously cut four grooves measuring 200 mm 50 mm 50 mm, which were simulations of material defected. All samples were made in areas where maximum steam temperatures were operating. Welds were tested with destructive and non-destructive methods to determine their quality and define non-compliances detected. The L21HMF cast steel was subjected to a revitalization process, which consisted the hull in subjecting heat treatment in order to obtain favourable structural changes and improve the strength properties. Non-destructive examinations and hardness tests were carried out on the remedial weld, indicating the required quality of repairing remedial weld. Comparative study is aimed at demonstrating the main welding problems during the repair welding of exploitation steam turbine hulls.
Operational Verification of a Ship Main Power System Element Choice – Case Study
Authors: Adamkiewicz Andrzej , Fydrych Janusz
Published: June 2020

The article refers to results and conclusions on post-emergency repairs of a turbo-charging system of a DEUTZ engine of the SBV 8M 628 type of 1715 kW – the main power unit of a cement carrier. The failure of the turbocharger led to severing of a part of the exhaust outlet valve head. In order to determine the cause of the turbocharger fault, parametric identification of the reference state of the turbocharging system interacting with the ship main power engine has been carried out. The post-emergency servicing of the turbocharger comprised mounting a new blade rim of expansive instruments of smaller capacity than the so far used. Control measurement results of the power system after the replacement of the turbocharger turbine nozzle have been presented. Limitations of correct engine operation have been noted in the range of maximum load with continuous power (MCR). A range of corrective maintenance servicing of fuel equipment has been presented. Using the values of measured torque at the propeller shaft, incorrect interaction between the shaft and the main engine has been noted. A new propeller, adequate to the design operational parameters of the engine characteristics, has been chosen and mounted. The correctness of turbine expansive instrument replacement has been verified by correct interaction between the elements of the power system: propeller – main engine – turbocharging system. Thus, a wider range of economically acceptable ship operation has been obtained.
Passion and researcher’s identity
Authors: Melosik Zbyszko
Published: June 2020

The aim of the article is to analyse various contexts of passion perceived as an important component of researcher’s identity. First, passion is confronted with the concept if rationality which dominates the university thinking about research. Second, passion is considered in relations to intrinsic and extrinsic motivation. Next, the author concentrates attention on factors which limit the passion development: present commercialization of research as well as their permanent indexation and evaluation, re-locating the researcher’s energy on permanent reporting and detailed juridization of academic reality. At the end the possibility of passion in contemporary research is optimistically confirmed by the idea of academic community and academic freedom.
Macro-political determinants of school culture
Authors: Śliwerski Bogusław
Published: June 2020

The subject of the article is the involvement of the school’s culture in the centralistic education policy, which is led by all, successively changing governments. It started with systemic reform of educational system in 1999. The author pays attention to the extent to which such a policy destroys the innovativeness of teachers. The only solution to this situation is the return to the anti-systemic micro-innovation movement in public education due to it restores the sense of dignity and professional self-fulfillment of teachers.
School culture in its descriptive and normative understanding. Selected exemplifications
Authors: Nowosad Inetta
Published: June 2020

The article addresses the ambiguity in understanding school culture and its potential research implications. The analyses were embedded within two key approaches: normative and descriptive, illustrating selected exemplifications of theoretical positions of school culture in German-speaking countries. Also, the potential for integration of both approaches into a new model of school culture was proposed by La Tefy Schoen and Charles Teddi in 2008, which terminated the separation between descriptive and normative approaches to school culture.
Scholar in the spectacle of parametrization – between authenticity and game of appearances
Authors: Cybal-Michalska Agnieszka
Published: June 2020

By referring to the metaphor of the theater – the theater of the reality of parametrization in which we the people of science participate – the author is wondering whether the servitude towards science can be identified with scientometrics, i.e., parametrization in the form that is known to us, where at least two of the indicators are subjective, namely: the type of the criteria and their weight. In the article, the emphasis is placed on the theatrical space of construction of the relation of “co-presence” which is not free from our need for recognition, individuality, uniqueness and being the best, at the top of the ranking of parametrization, “skillfully” playing our role of the “scientist” on the stage, which connects but also divides because of that, i.e. the place occupied on that stage. The acts are the spaces of our scientific activity, which – by capturing the “difference” in relation to others and the “difference” in relation to ourselves in time – allow us to be, to crystallize our image, to further define ourselves and to be recognizable in the role of a scientist in a reality that was not chosen by us, but is implemented according to codified rules of the game.
„New media” usage in the context of improving the quality of life of elderly from Poland
Authors: Zychowicz Maciej
Published: June 2020

Subject of the report is media exclusion of elderly people in Poland, especially in area of Internet-connected activities as well as changes in social interaction model which are connected with development of the Internet. Nowadays we face with Internet revolution witch whom technological progress and web tools development allowed to partly virtualize interpersonal contacts and change the way people interact with others. Even in area of everyday life the Internet revolution allowed to modify our behaviors which were immutable from ages.The aim of this report is to assess the level of inclusion of the elderly people from Poland into area od virtual contacts and other activities as well as presenting their methods to use different media.
„Teachers as the Greatest Value of Our Nation” – Rhetoric, Practice and Effects of „reform” of Teacher Training in England and Wales
Authors: Potulicka Eugenia
Published: June 2020

Initial teacher training in England and Wales is radically reformed since the 2010 year. Many new ways of training were introduced, namely: School-Centered Initial Teacher Training, School Direct, apprenticeship, Teach First, Troops to Teachers and others. The role of universities in teacher training is severe diminished with many implications for the quality of teachers and teaching as well as for the identity of academic teachers, their role and the lack of stability. Of course those changes have a lot of implications for universities, especially for their Schools of Education. Some of them disappeared.
Meaningful Learning: The Main Constitutive and Consecutive Components and their Presence in Science Teaching
Authors: Abu-Ghaneema Elias
Published: June 2020

This pilot study aims to identify the presence of components which are consistent with meaningful learning in science teaching. Semi-structured interviews were conducted with six science teachers and the results show that some of the teachers’ perceptions and practices in science teaching are consistent with meaningful learning components. Science teachers’ descriptions led to the identification of six categories which can be classified into two sets of components: Constitutive (e.g., ‘authenticity’ and ‘prior knowledge’) and. Consecutive (e.g., ‘cooperative learning’, ‘knowledge construction’, ‘learning by doing’ and ‘feedback’). Based on these results, it can be concluded that there is a positive change in teachers’ perceptions and implementation of pedagogical processes for promoting meaningful learning in science teaching. The implications of these findings for future research are discussed.
After experiences in writing my master’s thesis in the eye of the work of my doctoral dissertation. The essay about my struggle with my research technique
Authors: Szafrański Mateusz
Published: June 2020

This article presents experiences associated with writing my master’s thesis and designing research to my doctoral dissertation. In this text I indicate determinants that shape my research addescence is favourable to conducting reliable research projects. In both cases research sets in pedagogy of people with intellectual disabilities (oligophrenopedagogy) – a detailed science of special pedagogy that deals with an individual and social life of a person with intellectual disabilities.
Perceiving oneself as a human being and as a student by the junior high school pupils before beginning their secondary school education
Authors: Jaskulska Sylwia
Published: June 2020

In the text, I presented a part of the results of the studies concerning the transition of the school youth from junior high school to high school. In the light of this results, I answered the question on how the students graduating from junior high schools in Poznań in 2015 perceived themselves as a person, especially in the role of a student. The image is generally positive, although it is varies among the students with different resources (e.g. grades, level of involvement).
Diversity and the Difficulty of Living it: The Case of Public Spaces in Skopje (North Macedonia)
Authors: Mojanchevska Katerina
Published: June 2020

Ethnic diversity and cultural heterogeneity are a reality for the city of Skopje, the capital of North Macedonia. The changing ethnic demography and redressed power-balance between majority and non-majority groups on local level have spurred a turbulent conflict – that of governance of diversity in public space. This paper aims to understand citizens’ views on how language, ethnicity, religion and collective cultural symbols are legitimised through the political, social and symbolic value of public spaces in their neighbourhoods. The results indicate that the political value of public spaces to stimulate contact, deliberation and debate among citizens on issues of their concern is undermined. Public spaces in Skopje are not planned and managed through a wide forum of citizen engagement. The colliding ethnonationalism and symbolic power struggle between the major ethnic groups result in co-ethnic preferences in socialisation and selection of public spaces. The concept of “the appropriate citizen” constructed through the symbolic meaning of public spaces perpetuates ethnonational rhetoric and supports expressions of citizenship that are limited to the nation-state and ethnic identification. In opposition to contact theory, this research indicates that self-segregation of ethnic groups can be prevalent in multi-ethnic neighbourhoods. This should make us think of the context where the contact is established and not only of the content of the interaction.
The Importance of Introducing a Merit-Based Hiring System in North Macedonian Governments
Authors: Hubbell Larry , Kreci Veli
Published: June 2020

In this article, the authors present several topics related to the nascent development of a merit-based hiring system in North Macedonia. This paper employs a normative approach. We advocate for a merit-based hiring system, similar to the American model. First, we explore the pressure exerted by the European Commission to adopt a merit-based system at all levels of government as a condition for entry into the European Union. Second, we delve into the patronage system in North Macedonia. Third, we provide a short history of patronage in the United States and the difficulty that nation had in curbing its entrenched patronage system. Fourth, we discuss the advantages of a merit-based hiring system, namely the creation of good governance, the improvement of employee morale, the development of more public confidence in government, the reduction of the influence of ethnic politics and the furtherance of the rule of law. Finally, we present an example drawn from the American federal government about the basic procedures of a merit-based hiring process.