Shape memory alloys are characterised by interesting properties, i.e. shape memory eﬀect and pseudoelasticity, which enable their increasing application. Thermomechanical aspects of martensitic and reverse transformations in TiNi shape memory alloy subjected to tension tests were investigated. The stress-strain characteristics obtained during the tests were completed by the temperature characteristics. The temperature changes were calculated on the basis of thermograms determined by an infrared camera. Taking advantages from the infrared technique, the temperature distributions on the specimen’s surface were found. Heterogeneous temperature distributions, related to the nucleation and development of the new martensite phase, were registered and analysed. A signiﬁcant temperature increase, up to 30 K, was registered during the martensitic transformation. The similar eﬀects of the heterogeneous temperature distribution were observed during unloading, while the reverse transformation, martensite into austenite took place, accompanied by signiﬁcant temperature decrease.
In this study a group of selected transformation kinetics equations is applied to describe the isothermal ferritic transformation in austempered ductile iron (ADI). A series of dilatometric tests has been carried out on ADI at different temperatures. The obtained experimental data are utilized to determine the parameter values of the considered kinetic equations. It is found that the transformation kinetics models by Starink, Austin and Rickett are substantially more effective at describing the ferritic transformation in ADI than the much celebrated Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation. Furthermore, it is demonstrated that evaluating the kinetic parameters using the least squares method instead of calculating them from vastly used formulas can significantly improve the accuracy of the JMAK model’s predictions.
Dr. Artur Obłuski of the University of Warsaw tells us about research into political, social, and religious transformations in Sudan in the Middle Ages, the present-day importance of archaeological discoveries, and the meaning of the word “UMMA.”
“Isolation would be most unfortunate. We would be doing science in our own company, completely indifferent to what is happening outside our own universe. This would be totally self-destructive and I hope it will never happen,” says Professor Michał Głowiński in an interview with Grzegorz Wołowiec, titled “A Time Unexpected,” a fragment of which is presented below.
The radiation of sound waves from partially lined duct is treated by using the mode-matching method in conjunction with the Wiener-Hopf technique. The solution is obtained by modification of the Wiener-Hopf technique and involves an infinite series of unknowns which are determined from an infinite system of linear algebraic equations. Numerical solution of this system is obtained for various values of the problem parameters, whereby the effects of these parameters on the sound diffraction are studied. A perfect agreement is observed when the results of radiated field are compared numerically with a similar work existing in the literature.
The article discusses the problem with modifications of plans of water areas and the forms of their borders which have been inscribed into the history of all city structures related to water. It can be observed that the modifications made in recent decades very often concern the transformations of former industrial sites. Many such structural changes are taking place within signifi cant areas which have fragmented central parts of cities and created voids in the urban fabric. They are being applied to many former shipyards and ports. Research shows that the formation of new connections between land and water in these transformation processes is essential. More frequently, those conversions that are currently being realized change the constructions of wharves and lead to the development of plans drawing new borders between land and water. In these cases water is introduced into land areas and new land surfaces are being created over existing bodies of water. These operations can be considered extremely valuable in achieving the intended eff ects of transformations of post-industrial areas. They are perceived as an excellent possibility to strengthen the relationship between the city structure and water. At the same time they create an opportunity to achieve a high quality of architectural and landscape solutions and the quality of spaces in both social and economic terms.
Gothenburg is the second-largest city in Sweden, capital of Västra Götaland County Region. It is situated on the west coast of Sweden with the port area located along the Göta Älv River. Due to economic restructuring, waterfront redevelopment emerges as an attractive option to boost economic growth of the city. The aim of this paper is to shed light on conditions of the transformation process of two neighboring areas: Frihamnen and Ringön. Publicly initiated and privately executed waterfront redevelopment in Gothenburg transforms industrial grounds into residential and service oriented areas in Eriksberg, Lindholmen and Frihamnen. The collaborative process of a “developer dialogue” crafts a redevelopment in a consistent way with taking into consideration city’s long-term planning strategy, specifi c needs and opportunities of the neighbourhoods, but also market and fi nancial realities of development community. Another example is a slow and spontaneous transformation of post-industrial areas in Ringön, where still active small industrial fi rms, services, cultural and artistic initiatives take place in the close proximity to the city centre. Results show the waterfront transformation attracts “developers’ dialogue” giving the opportunity to build a coherence for spatial, environmental and socio-economic development. Yet fragmented redevelopment of brownfi eld areas strengthen polarization between dynamic and carefully planned Frihamnen and spontaneously growing Ringön. This paper contributes to the knowledge on the complexity of urban post-industrial transformation.
Extensive efforts have been made for many years by the power generating industry to replace conventional solid and liquid insulation with synthetic materials. Those measures are aimed at increasing the load capacity, improved fire safety and extending transformer life during exploitation. Modern insulating materials include aramid fibre-based paper and insulating fluids made of synthetic and natural esters. The paper presents research results of the electrostatic charging tendency (ECT) of mixtures of fresh and aged mineral oil Trafo En with synthetic ester Midel 7131 and natural ester Midel 1204. The measurements were taken in a flow-through system using the pipes made of metal, cellulose and aramid paper. The influence of the liquid flow velocity, the type of material of the measuring pipe and the mixture content on the level of the streaming electrification current generation was determined.
In the submitted study, the author shows that Paul in the propositio (12,1-2) the section of encouragement (12,3-15,13), although he does not use the word syneidēsis directly, but the words used in it refer to him in conjunction with his basic functions and prove in this way how fundamental it is to renew the mind in the right, i.e. salvifically effective, education of Christian conscience. He does so in the encouragement context to make the recipients aware of how important it is to have a renewed mind and conscience in being and continuing to become a Christian in everyday and concrete living as well as practicing faith in Jesus. With propositio, he makes the foundation on which he builds the paraclesical message of the Letter. It clearly states that permanently renewed by the Gospel of God mind, is an absolute condition for an uninterrupted evangelical renewal of conscience. Thus, renewed in this way conscience is the only deity of mercy granted to sinful humanity, which guarantees constant faithfulness to its norms of judgment with God’s justice revealed in Christ, the Son of God, or his absolute righteousness, which is an indispensable condition for achieving eternal salvation.
The subject of this paper is the study of the specificity of the transformation of the urban public spaces of the Western world and the problem of the multi form nature of this phenomenon. The Author uses such concepts as that of the "hybrid" and of "hybridization" borrowed from the field of natural sciences and explains the reasons for their introduction within this specific scope of research in a broad manner.
The current climate warming results in a quick recession of glaciers on the northern slopes and valleys of the Lindströmfjellet-Hĺbergnuten mountain ridge in Nordenskiöld Land. The equilibrium line altitude has risen from c. 500-550 m in 1936 to c.750 m in 2001 and c. 800 m in 2006. The slopes, almost completely glaciated during the Little Ice Age, and even in 1936, have mostly been abandoned by glaciers afterwards. The upper parts of the glaciers undergo a clear retreat diminishing their accumulative (firn) fields. The lower parts of the active glacial tongues have been transformed into marginal zones built of dead ice covered with morainic and glacifluvial deposits. The surfaces of the marginal zones are progressively lowered due to ablation of dead ice. The state of the described glaciers is not balanced under the current climatic conditions. Thus, the landscape transformation of the mountain ridge will most certainly continue.
Within this article a large scope of issues associated with development conditions and specifics of shaping the new image of Gdańsk waterfront was presented. The special attention was paid to its part situated within its central zone, located within the city centre. This area was playing a key role in development of the city, as within its boundaries many activities associated with shipbuilding and port industry were located. One has to mention that the Granary Island – a place located in the heart of the waterfront area – was an area of special interest for the port and shipbuilding activities, which relates also to the embankments of both Old and New Motława rivers. But the technological changes in the maritime transportation as well as wart-time destruction of the city decided about the major changes in structure of this area and shifting the port and shipbuilding operations to other sites located to the north from the city centre. Therefore, starting from the year 1945, one could observe the on-going discussion regarding the future of this area, although only in 1990-ties it was possible to actually start implementation of these ideas. At the same time – along with appearance of the demand for the types of apartments, offi ce and commercial spaces that are located on the waterfront – the urban space of Gdańsk waterfront has become interesting for both municipal authorities and developers. In result, a large amount of projects have already been implemented or planned, which contributes towards creation of the new, waterfront urban district of Gdańsk. Within its structure one can distinguish a number of particular sites, including ones still awaiting for their development chances. In the text of this article there were presented the most important parts of these plans, as well as future development directions of urban waterfront structures.
In accordance with the principles of conducting revitalization activities specified in the Revitalization Act in force from 9 October 2015 and horizontal guidelines for revitalization in operational programs for 2014-2020, the preparatory phase of the revitalization process should include multi-layered analyzes concluded with deductions included in communal urban regeneration programs. The article describes the role of student architectural and urban competitions performed in cooperation between municipalities and universities as innovative analytical and conceptual activities that could form the basis for specifying recommendations in revitalization strategies planned by a given municipality. The infl uence of the student competitions’ results on the development of the city revitalization strategy is presented on grounds of periodic competitions organized at the Faculty of Architecture of the Gdańsk University of Technology in cooperation with the Department of Plans and Marketing of the City Hall of the City of Gdańsk.
Clarifying the genetic background of the drought-tolerance trait is a crucial task that may help to improve plant performance under stress by a genetic engineering approach. Dehydration-responsive element-binding protein (DREB) is a transcription factor family which modulates many stress-responsive genes. In this study, we isolated a DREB homolog gene named ZmDREBtv from Zea mays var. Tevang-1. Using bioinformatic tools, a number of InDels and SNPs in ZmDREBtv sequence different from the reference accession were identified. In addition, based on deduced protein sequence similarity, ZmDREBtv was assigned to transcription factor DREB2 class as featured by a conserved DNA binding domain - AP2. The ZmDREBtv construct under thecontrol of the rd29A promoter was transformed into a drought-sensitive maize plant, K7 line. The transgenic plants were assessed with reference to molecular and phenotypic characteristics related to the drought-tolenrance trait. The results proved that the maize plants carrying ZmDREBtv gene showed enhanced tolerance and better performance to the water-deficit environment at different stages, compared to the wild-type plants.
The article depicts the personage of Karol Modzelewski (1937–2019) the outstanding activist for freedom of Poland, long-term political prisoner, prominent medievalist historian and full member of the Polish Academy of Sciences.
One of the most important issues that power companies face when trying to reduce time and cost maintenance is condition monitoring. In electricity market worldwide, a significant amount of electrical energy is produced by synchronous machines. One type of these machines is brushless synchronous generators in which the rectifier bridge is mounted on rotating shafts. Since bridge terminals are not accessible in this type of generators, it is difficult to detect the possible faults on the rectifier bridge. Therefore, in this paper, a method is proposed to facilitate the rectifier fault detection. The proposed method is then evaluated by applying two conventional kinds of faults on rectifier bridges including one diode open-circuit and two diode open-circuit (one phase open-circuit of the armature winding in the auxiliary generator in experimental set). To extract suitable features for fault detection, the wavelet transform has been used on recorded audio signals. For classifying faulty and healthy states, K-Nearest Neighbours (KNN) supervised classification method was used. The results show a good accuracy of the proposed method.
In this paper, a modified sound quality evaluation (SQE) model is developed based on combination of an optimized artificial neural network (ANN) and the wavelet packet transform (WPT). The presented SQE model is a signal processing technique, which can be implemented in current microphones for predicting the sound quality. The proposed method extracts objective psychoacoustic metrics including loudness, sharpness, roughness, and tonality from sound samples, by using a special selection of multi-level nodes of the WPT combined with a trained ANN. The model is optimized using the particle swarm optimization (PSO) and the back propagation (BP) algorithms. The obtained results reveal that the proposed model shows the lowest mean square error and the highest correlation with human perception while it has the lowest computational cost compared to those of the other models and software.
Results of a research on influence of chromium, molybdenum and aluminium on structure and selected mechanical properties of Ni-Mn-Cu cast iron in the as-cast and heat-treated conditions are presented. All raw castings showed austenitic matrix with relatively low hardness, making the material machinable. Additions of chromium and molybdenum resulted in higher inclination to hard spots. However, a small addition of aluminium slightly limited this tendency. Heat treatment consisting in soaking the castings at 500 °C for 4 h resulted in partial transformation of austenite to acicular, carbon-supersaturated ferrite, similar to the bainitic ferrite. A degree of this transformation depended not only on the nickel equivalent value (its lower value resulted in higher transformation degree), but also on concentrations of Cr and Mo (transformation degree increased with increasing total concentration of both elements). The castings with the highest hard spots degree showed the highest hardness, while hardness increase, caused by heat treatment, was the largest in the castings with the highest austenite transformation degree. Addition of Cr and Mo resulted in lower thermodynamic stability of austenite, so it appeared a favourable solution. For this reason, the castings containing the highest total amount of Cr and Mo with an addition of 0.4% Al (to reduce hard spots tendency) showed the highest tensile strength.
A transformer is an important part of power transmission and transformation equipment. Once a fault occurs, it may cause a large-scale power outage. The safety of the transformer is related to the safe and stable operation of the power system. Aiming at the problem that the diagnosis result of transformer fault diagnosis method is not ideal and the model is unstable, a transformer fault diagnosis model based on improved particle swarm optimization online sequence extreme learning machine (IPSO-OS-ELM) algorithm is proposed. The improved particle swarmoptimization algorithm is applied to the transformer fault diagnosis model based on the OS-ELM, and the problems of randomly selecting parameters in the hidden layer of the OS-ELM and its network output not stable enough, are solved by optimization. Finally, the effectiveness of the improved fault diagnosis model in improving the accuracy is verified by simulation experiments.
The paper analyzes the changing public-private dynamics in higher education in Poland in 1990-2016 and beyond, focusing on the processes of internal and external de-privatization of the system. De-privatization of higher education – viewed also as its republicization – is caused by declining demographics and may lead to the demise of the largely demand-absorbing private higher education. Poland is shown as moving against the two powerful global trends related to privatization: private sector growth and increasing reliance on cost-sharing. Data related to funding and provision in 1990-2005 (expansion) and 2006 and beyond (contraction) are analyzed in detail, and policy implications of ongoing and expected changes are discussed.
The article presents personal memories of Professor Aleksander Koj’s alumni. Professor Aleksander Koj was a world-class biochemist of significant scientific achievements, a renowned authority in the field of acute-phase response regulation and acute-phase proteins. He was an excellent academic, a true Master, admired and followed by many Polish biochemists. Thrice he served as the Rector of the Jagiellonian University in Kraków. He navigated the University through a difficult time of political transformation in Poland, modernized the management system of the University and led to the commencement of the construction of the new University campus. He was the co-creator and the first Chairman of the Conference of Rectors of Academic Schools in Poland. He will be remembered as a devoted community worker aiming at strengthening the bond between the Polish community abroad and our homeland, propagating knowledge, promoting the concept of European integration, democracy and tolerance, as well as the collaboration between scientists, artists and men and women of culture. He was wise, righteous, and noble. Many had the honor of calling him their friend, and a great many saw in him a moral authority.
This article brings together two authors/two poems and makes them enter into an intertextual dialogue that involves the discourses of the new materialism (Catherine Malabou), postphenomenology (Natalie Depraz and Marc Richir) and Delphic maxims. Concepts like plasticity, transformation masks, alterations in the passage of time (chronos, kairos, aeon), subjectivity, emotional excess, and the living body are used to establish the foundations a poetic conversation, which, for all one knows, may be fortuitous or in a way preordained.