Due to the use of welded finned tubes in heat exchangers, gas blocks are characterized by very good electric energy production performance, and their reliability can reach 98%. Finned tubes used in ...heat exchangers are usually welded. Such tubes should be characterised by the following properties: high thermal performance, good resistance to high-temperature corrosion in a flue gas atmosphere, and appropriate joint strength and hardness. The most popular technology for welding finned tubes is MAG. MAG-welded joints are characterised by considerable spattering, weld discontinuities (up to 60%), and non-axial fin alignment. Such irregularities result in a considerably reduced heat flux due to the heat transfer resistance occurring in the welded joint. It has been shown that with weld discontinuities of 20%, the thermal performance of welded finned tubes reduces considerably. This paper proposes the possibility of welding finned tubes with a laser. The thermal properties of laser-welded finned tubes were compared with those of MAG-welded tubes. It was found that the thermal performance of welded finned tubes was three times higher than that of plain tubes. However, the thermal performance was not found to be affected by the welding technology. The correct heat flow at the level of 95% occurs in the tube/fin joint even with joint penetration of 0.01 mm, however, the absence of metallic continuity in a joint results in a drastically reduced thermal performance (by 50%) and the overheating of fins, which affects their durability.
The article discusses the effect of the hybrid-welding process (laser–electric arc MAG Metal Active Gas) on the structure and properties of butt joints (having various thicknesses, i.e., 5 mm and 7 ...mm) made of steel S960QL. Welding tests were performed in the flat position (PA) and in the horizontal position (PC). Joints made of steel S960QL in the above-presented configuration are present in elements of crane structures (e.g., telescopic crane jibs). The welding tests involved the use of the G Mn4Ni1.5CrMo solid electrode wire and the Ar+18% CO2 shielding gas mixture (M21) (used in the MAG method). Non-destructive visual and radiographic tests did not reveal the presence of any welding imperfections in the joints. The welded joints obtained in the tests represented quality level B in accordance with the requirements of the ISO 12932 standard. Microscopic metallographic tests revealed that the heat-affected zone (HAZ) contained the coarse-grained martensitic structure resulting from the effect of the complex welding thermal cycle on the microstructure of the joints. Destructive tests revealed that the joints were characterised by tensile strength similar to that of the base material. The hybrid welding (laser–MAG) of steel S960QL enabled the obtainment of joints characterised by favourable plastic properties and impact energy exceeding 27 J. The tests revealed the possibility of making hybrid-welded joints satisfying the quality-related requirements specified in the ISO 15614-14 standard.
Sprawozdanie z międzynarodowej konferencji naukowej „W poszukiwaniu europejskiej doktryny wolności słowa”, Poznań, 10 march 2016 r. (opr. Michał Urbańczyk)
This paper presents the results of tests on the fabrication of welded joints in S1300QL steel according to the requirements of ISO 15614-14 and ISO 12932. The butt-welded joint without bevel was made ...from 350 × 150 × 8 mm sheets. The welding process was carried out at the hybrid welding (laser–MAG) station. MAG means metal active gas. The test welded joints were subjected to non-destructive and destructive testing. Visual and radiographic examinations were carried out. The distribution of HV10 hardness was determined in the weld, the heat-affected zone, and the base material. The microstructure of these areas was also analysed for the presence of hard and brittle hardening products and non-metallic inclusions. Tensile strength and yield strength, as well as bending strength, were assessed in the mechanical property tests. The impact test was performed in accordance with ISO 9016.
POLITICALLY CORRECT HATE SPEECH Demenko, Anna; Urbańczyk, Michał
Ruch Prawniczy, Ekonomiczny i Socjologiczny (1960),
09/2020, Volume:
82, Issue:
3
Journal Article
Peer reviewed
Open access
In the paper we discuss the reasons behind a specific permissiveness of the Polish judicial authorities with regard to hate speech. Hate speech is criminalized by various provisions of the Polish ...Criminal Code. But as conducted surveys and statistics show, these regulations do not seem to be used adequately. The acceptance of hate speech does not necessarily result from the fact that we are a less tolerant society, but also to a large extent, from the fact that the scope of what is allowed to be said, especially publicly, is in Poland very broad. Paradoxically, it seems that in this new democracy’ there is more freedom of speech than in Western countries, where political correctness plays a very important role in public and social life. The lack of responsibility that goes with freedom of speech and of boundaries on what might be expressed in public, the scurrilous language used also by high-ranking officials, influence the rules of socially acceptable behaviour. These rules also influence the scope of what is considered criminal behaviour. When tackling the problem of the acceptance of hate speech, it is also very important to remember that legal acts, especially criminal law, might not necessarily be the best way to change the attitudes in a society. Restrictions on freedom of speech might not only have a freezing effect but also be counterproductive – that which it is prohibited to say tends to be said more. The problem is to strike the right balance between those two possible outcomes.
Sprawozdanie z międzynarodowej konferencji naukowej „W poszukiwaniu europejskiej doktryny wolności słowa”, Poznań, 10 march 2016 r. (opr. Michał Urbańczyk)
Zgodnie z tytułem celem opracowania jest przedstawienie poglądów Raymonda Arona na temat wolności, zwłaszcza jej istoty oraz roli, jaką odgrywa w demokracji liberalnej. Przy czym Aron pisał nie tyle ...o wolności w liczbie pojedynczej, lecz o wolnościach w liczbie mnogiej, wskazując między innymi na wolności realne i formalne (w szczególności wolności polityczne) oraz wolność zbiorowości jaką jest naród
The essence of democracy is the rule of the sovereign, that is the nation, today understood as all of the state’s citizens. At present, the most common type of governance is representative democracy, ...exercised by representatives elected from the citizens themselves. Therefore, for the proper functioning of liberal democracy it is difficult to find a more important issue than the procedure for the election of those who govern us. The article presents two alternative electoral systems: an alternative voting system (AV) and the system of Single Transferable Vote (STV).
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