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Number of results: 6
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Abstract

This study presents results of stress rupture test of MAR-M-509 cobalt alloy samples, as-cast and after surface refining with a concentrated stream of heat. Tests were conducted on samples of MAR-M-509 alloy castings, obtained using the lost-wax method. Casting structure refining was performed with the GTAW method in argon atmosphere, using the current I = 200 A and electrical arc scanning velocity vs = 100, 150, 200 and 250 mm/min. The effect of rapid resolidification of the MAR-M-509 alloy on the microstructure was examined and significant improvement in stress rupture test was observed.
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Abstract

The paper summarises results of measurements of remelting area geometry, thermal efficiency and melting efficiency characterising the surface remelting process applied to castings of MAR-M-509 cobalt alloy. The remelting process was carried out with the use of GTAW (Gas Tungsten Arc Welding) method in protective atmosphere of helium, at the electric current intensity in the range from 100 A to 300 A, and the electric arc scanning velocity vs in the range from 200 mm/min to 800 mm/min. The effect of current intensity and electric arc scanning velocity on geometrical parameters of remeltings, thermal efficiency, and melting efficiency characterising the remelting process has been determined.
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Abstract

The study consisted in assessing the influence of surface and volume modification on the characteristics of high-temperature creep of castings made of waste products of nickel-based superalloys IN 713C and the MAR-247. The results of high-temperature creep tests performed under conditions of two variants of research were analysed. The characteristics of creep according to variant I were obtained on the basis of earlier studies of these alloys with the parameters T=982o C, σ=150MPa [1]. Variant II included carrying out creep tests of alloy IN713C with the parameters T=760o C, σ =400MPa and alloy MAR247 with the parameters: T=982o C, σ=200MPa.Developed creep characteristics were compared with the results of these alloys with the parameters according to variant I of the study. It was observed that the conditions of experiments carried out depending upon the value of the creep test temperature and stress with the creep stability depends on the size of the macrograin (I variant of the studies) or such influence was not observed (II variant of the studies). Stability of samples with coarse structure in variant I of creep tests was significantly higher than the samples with fragmented grain. It was found that the observed stability conditions are dependent on the dominant deformation mechanisms under creep tests carried out - diffusion mechanism in variant I and a dislocation mechanism in variant II of the study. The conditions for the formation and growth of the cracks in the tested materials, including the morphological characteristics of their macro-and microstructure were tested.
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Abstract

The author in his article deals with the role that Mary of Nazareth, the mother of Messiah, the Gebirah, played in the economy of salvation. The title Gebirah means the dignity of the king’s mother and the special power of her influence. Therefore, the Books of Kings almost always mention the name of the king’s mother by introducing the description of each Judah ruler from the Davidic dynasty from which the Messiah was born. The dignity of Gebirah was given to the king’s mother at the time of her son’s enthronement. The king’s mother received the prestigious title of Gebirah (2 Kings 5:3; Jer 13:18), because she gave birth to her son (geber), who became king (2 Sam 23:1). They mention three texts of the Bible about the mother of the Messiah, depicting an important figure of a mother’s role (Genesis 3:15; Jes 7:14 and Mich 5:2). Both the figure of the king and his mother prefigure the Messianic King Jesus (2 Sam 7:10-17) and his mother Mary. Mary, the Mother of Jesus, considered to be a messianic personification of the entire people of Israel, becomes the new Daughter of Zion. Mary as the messianic Gebirah is actually the Mother of the Church.
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Abstract

Szeroko rozumiane pojęcie ludzi morza obejmuje nie tylko tych, którzy przemierzając akweny, ryzykowali swoim życiem, ale i tych, którzy wysyłali ich w rejs i ryzykowali swoim majątkiem. Analiza obejmuje środowisko ludzi morza w głównych portach bałtyckich (Gdańsk, Szczecin, Elbląg, Stralsund, Kołobrzeg) w zależności od stanu badań. Środowisko armatorów dość żywo reagowało na zmienne koniunktury gospodarcze. Należy też zauważyć, że w coraz większym stopniu ich aktywność zależała od polityki gospodarczej rządu centralnego (system podatkowy, monopolowy, akcyzowy). Widoczny jest też związek armatorstwa z prowadzeniem działalności kupieckiej oraz dużą popularnością spółek armatorskich zawiązywanych w celu prowadzenia wspólnych interesów handlowych, wzmacnianych poprzez koligacje rodzinne i towarzyskie. W okresach prosperity wzrastała liczba żaglowców, łatwiej było szyprom i marynarzom znaleźć pracę na statku. Kwestia ich zatrudnienia była regulowana odgórnie regulaminami i zapisami wilkierzy miejskich. Brak było jednak państwowych lub miejskich ustaw socjalnych, a zabezpieczenie życia i zdrowia lub bytu rodziny zależało od inicjatyw prywatnych lub gildii.
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