Wyniki wyszukiwania - BazTech

1

Sposoby wyznaczania efektów II rzędu w ściskanych elementach żelbetowych

Dawczyński S.

Materiały Budowlane

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2013

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nr 2

50-51

EN

Methods of second order effects determining recommended in Eurocode 2 for reinforced concrete axial loaded elements calculations have been presented in the paper. Besides general method, both simplified methods based on nominal stiffness and nominal curvature were discussed in detail. Some basic formulas needed for calculations according to simplified methods have also been provided.

2

Oznaczanie wielopierścieniowych węglowodorów aromatycznych (WWA) w biogazie

Król A., Holewa J.

Nafta-Gaz

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2012

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R. 68, nr 12

1135--1139

PL

W pracy opisano metodykę pozwalającą na oznaczanie związków z grupy WWA w biogazie przy zastosowaniu techniki HPLC z detektorem fluorescencyjnym. Opracowana metoda została zwalidowana w zakresie pozwalającym na określenie zawartości 12 WWA, najczęściej oznaczanych w próbkach środowiskowych. W pracy przedstawione zostały wyniki oznaczenia WWA w próbkach biogazu pochodzącego z różnych źródeł, tj. oczyszczalni ścieków oraz składowisk odpadów. Wyznaczone stężenia pozwoliły na poglądowe stwierdzenie, że zawartość WWA w przebadanych próbkach biogazu nie jest wysoka w porównaniu z zawartością tych substancji w próbkach gazu ziemnego.

EN

This work presents the methodology for the determination of compounds from the PAH group in biogas, using the HPLC technique with a fluorescent detector. The elaborated method was validated within the scope which enables determination of 12 PAH content, most often determined in environmental samples. The work also presents the results of PAH determination in biogas samples from various sources i.e. waste-water treatment plant, industrial waste stockpiles. The designated concentrations allowed for the stated view, that PAH content in tested samples of biogas is not high in comparison to the content of these substances in natural gas samples.

3

Determination of pseudo-viscosity coefficients for visco-elastic lubricants

Wierzcholski K.

Journal of KONES

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2010

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Vol. 17, No. 2

491-496

EN

In this paper we assume determination of pseudo-viscosity coefficients of visco-elastic non-Newtonian fluid flow directly near the cooperating micro-bearing surface. We show the constitutive stress-strain dependencies of non-Newtonian visco-elastic media with regard to the content of addition of nano-particles. The greater content of nano-particles and influences of superficial layer of cooperating surfaces on the dynamic oil viscosity, the more distinct non-Newtonian properties. The non-Newtonian properties create non-linear dependencies between strain and stress. Moreover the dynamic viscosity or apparent dynamic viscosity of oil often decreases along with shear rate increasing during motion. dynamic viscosity of oil inside very thin boundary layers depends on Young's modulus of the cell body being in contact with the oil. Considered visco-elastic oils with nano-particles have non-Newtonian pseudo-plastic properties, described in the beginning by means of Rivlin-Ericksen constitutive relations. Hence their stress-strain dependencies presented in this paper have the modified Rivlin-Ericksen form. Scientific efforts brought into this elaboration represent an impact to the considered domain by providing for some data on comparisons between boundary conditions for lubrication flow in super thin boundary layer lying on the external surface of biological cells of joint cartilage and boundary conditions for lubrication of micro-bearing of shaft diameter smaller than 2 mm.