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Badania powłok ochronnych stosowanych na formy metalowe

Kolczyk J., Kaźnica N., Żymankowska-Kumon S., Jamrozowicz Ł.

Prace Instytutu Odlewnictwa

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2017

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Vol. 57, no. 1

39--50

PL

Metoda odlewania kokilowego opiera się na odlewaniu do metalowych, trwałych form, co pozwala na uzyskanie dużej liczby odlewów o praktycznie identycznych kształtach. W porównaniu z technologią odlewania do form piaskowych ma ona wiele zalet. Tym samym jednak posiada zupełnie inne wymagania dotyczące zarówno warunków wypełniania formy, jak również krzepnięcia metalu. Dlatego istotny wydaje się być dobór odpowiednich pokryć ochronnych na formy, które spełnią zadania kontroli poszczególnych procesów, a także ułatwią usuwanie odlewu, czy przedłużą żywotność form metalowych. W ramach pracy wykonano badania lepkości dynamicznej oraz umownej powłok ochronnych (podkładowych, izolacyjnych i przewodzących ciepło) stosowanych na formy metalowe. Badania prowadzono w temperaturze 25°C. Dokonano również próby oceny ekologiczności stosowanych powłok w temperaturze ich nakładania na formy metalowe (200°C) oraz w temperaturze pracy form (400°C) na podstawie badań chromatograficznych.

EN

The die casting method is based on casting into permanent metal moulds, which makes it possible to obtain a large amount of casts with practically identical shapes. Compared to the technology of sand mould casting, this method has many advantages. However, it thus faces completely different requirements concerning the conditions of both filling the mould and metal solidification. That is why it seems important to select the appropriate protective coatings applied on the moulds, which provide control over the particular processes as well as facilitate the removal of the cast and prolong the durability of the metal moulds. The study included investigations of the dynamic and relative viscosity of protective coatings (ground, insulating and thermal conductive) used for metal moulds. The examinations were performed at 25°C. Also, an attempt was made at evaluating the environmental performance of the used coatings at the temperature of their application onto the metal moulds (200°C) as well as the temperature of the moulds’ operation (400°C) based on chromatographic tests.

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Powstawanie gazów w transformatorach napełnionych olejem mineralnym niezwiązane z występowaniem uszkodzeń wewnętrznych

Olejniczak H., Buchacz T., Bednarska B.

Energetyka

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2008

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nr 8-9

614-618

PL

Przedstawiono przyczyny i mechanizm tworzenia się gazów w olejach stosowanych współcześnie podczas początkowej eksploatacji nowych transformatorów z powodów innych niż uszkodzenie. Omówiono zjawiska związane z powstawaniem gazów tzw. pasożytniczych, a także będących efektem reakcji katalitycznych z metalami i materiałami konstrukcyjnymi stosowanymi do produkcji transformatorów. Omówiono problemy występujące w takich przypadkach przy właściwej interpretacji wyników badań chromatograficznych.

EN

Presented are causes and mechanisms of gas forming in oils used in present days during initial operation of transformers and having no connection with internal damages. Discussed are phenomena connected with formation of the so-called parasitic gases and also being the effect of catalytic reactions with metals and construction materials used for transformers production. Indicated are problems occurring in such cases based on appropriate interpretation of chromatographic research results.

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Profesor Maciej Wiewiórowski jako współtwórca nowoczesnych badań chemicznych w Polsce

Antkowiak W.Z.

Wiadomości Chemiczne

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2000

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[Z] 54, 11-12

939-947

EN

Professor Maciej Wiewiórowski is one of the most distinguished organic chemists in the world. He got his PhD in 1950 working on the chemical transformations of codeine with Professor J. Suszko at Poznań University. Next, he started developing his own research programme concerning the alkaloid composition of certain Lupinus species. Several of his students then are still continuing the structural and synthetic research in this topic. At the end of the fifties, he spent quite some time on his first long-term post-doctoral fellowship working with Professor Leo Marion in the laboratory of the National Research Council of Canada in Ottawa, and it appeared to be the beginning of his fruitful collaborations with many outstanding scientists in the world in the subsequent years. When working in this foreign laboratory, he took the opportunity to become acquainted with many modern research techniques, especially column chromatography and IR as well as other spectroscopic methods, which enabled him to propagate and popularize these techniques in our country when he returned. In the late sixties, being the Head of the Stereochemistry and Organic Spectrochemistry Division at the Adam Mickiewicz University in Poznań, he began to organize, under the auspices of the Polish Academy of Science, a new field of research in Poland, then undeveloped worldwide, concerning the synthesis of nucleic acids. He both gathered young scientists, giving them special training, and organized new laboratories outside the University. In the early seventies, he moved with his group to the tentative laboratories at Noskowskiego Street in Poznań, there systematically and intensively expanding this research center, which finally resulted in the creation of the Institute of Bioorganic Chemistry of the PASc, a leader in the scientific world in carrying out modern biochemical research in nucleic acid as well as in protein chemistry. During recent years, already being retired, he is still very active in the life of the Institute , including carrying out research mainly on the reaction of nucleosides in a solid state.

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Indeksy topologiczne i ich znaczenie w badaniach chromatograficznych. Cz. 2

Pyka A.

Wiadomości Chemiczne

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1998

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[Z] 52, 9-10

727--754

EN

The prediction of physicochemical and toxicological properties of organic compounds with selected topological indices have been reviewed in monographs and in dedicated articles The first topological indices used to the prediction of selected physicochemical properties (boiling point, heat of formation, heat of vaporization, molar volume, molar refraction) were: Wiener index, polarity number and Platt's index. The Wiener index has been continuously modified In recent years topological indices have come prominently to the fore on several different fronts. The prime reason for wide publicity accorded to these indices has been the remarkable ability to correlate and predict the properties of a vast range of molecular species. Topological indices based on the adjacency matrix, on the distance matrix and on information theory were applicable to the calculation of many physicochemical properties and to the evaluation of biological and toxicological properties of organic compounds. The procedure for calculating the topological indices is illustrated in this work by the calculation of the topological indices based on the adjacency matrix (the Gutman index M1), ; the Randić connectivity indices (0X, 1X, 2X, 0Xv, 1Xv, 2Xv); on the distance matrix (the Wiener index W); the Pyka indices (A, 0B, 1B, 2B); the Balaban index (IB); the Schultz Molecular Topological Index (MTI) for pentamethylenediamine. It should be noted that none of these topological indices yet described differentiates between d and l isomers. The procedure for calculating the optical topological index (Iopt) for d and l isomers is illustrated in this work by the calculation of Iopt for d- and l-alanine. Applications of these topological indices for the correlation analysis are discussed. The TLC, the HPLC and the GC retention parameters of different organic compounds were calculated using equations with the topological indices. As examples, selected correlation equations for calculation retention parameters in TLC, in HPLC, and in GC were shown in this work Definitions of the three-dimensional Wiener number 3W and the mean square distance topological indices of the s-th order D(x) were presented.