Selected operational Problems of high-speed Rotors supported by Gas Foil Bearings

In this paper, several issues related to the operation of gas foil bearings were discussed. The description of the foil bearings\u27 operation was performed, with a special focus on the following issues: the friction processes taking place between the bearing elements together with the friction-generated heat, the appropriate selection of structural and coating materials, ensuring the bearing preload, and the vibration amplitudes in run-up and rundown of the rotor. The operational problems discussed are supplemented with practical examples. A very thorough understanding of the issues at stake makes it possible to specify more precisely the potential areas of application for foil bearings and take into account their operational properties in the contemplated implementations

Low-temperature zircon growth related to hydrothermal alteration of siderite concretions in Mississippian shales, Scotland

Zircon occurs in voids and cracks in phosphatic coprolites enclosed in siderite concretions in Mississippian shales near Edinburgh, Scotland. The zircon formed during hydrothermal alteration of early-diagenetic concretions and occurs as spherical aggregates of prismatic crystals, sometimes radiating. Vitrinite reflectance measurements indicate temperatures of ~270°C for the zircon-bearing concretions and the host shales. Molecular parameter values based on dibenzothiophene and phenanthrene distribution and occurrence of di- and tetra-hydro-products of polycyclic aromatic compounds suggest that the rocks experienced relatively high-temperature aqueous conditions related to hydrothermal fluids, perhaps associated with neighboring mafic intrusions. The zircon was dissolved from the concretions, transported in fluids, and reprecipitated in voids. This is the first record of the precipitation of authigenic zircon in sedimentary rock as a new phase, not as outgrowths

The occurrence of wakefieldite, a rare earth element vanadate, in the rhyolitic Joe Lott Tuff, Utah, USA

The high-silica rhyolitic Joe Lott Tuff was erupted at 19.2 ± 0.4 Ma from the Mount Belknap caldera, SW Utah. Certain units in the tuff contain two species of wakefieldite, the Nd- A nd Y-dominant types. They occur in disseminated streaks and patches in association with rhodochrosite, calcite, Fe oxide, cerite-(Ce), and a Mn silicate (caryopilite?), thought to have been deposited from hydrothermal fluids. The wakefieldites contain the highest levels of As (≤15.34 wt.% As2O5) and P (≤5.7 wt.% P2O5) yet recorded in this mineral, indicating significant solid solution towards chernovite-(Y) and xenotime-(Y). Thorium levels are also unusually high (≤14.2 wt.% ThO2). The source of the hydrothermal fluid(s) is unknown but might be related to uranium mineralisation in the region, in that As, V and U are commonly associated in such deposits. © 2019 Mineralogical Society of Great Britain and Ireland

Relationships between monazite, apatite and chevkinite-group minerals in the rhyolitic Joe Lott Tuff, Utah, USA

The high-silica rhyolitic Joe Lott Tuff was erupted at 19.2 ± 0.4 Ma from the Mount Belknap caldera in Utah, USA. Despite having a volume of ~150 km3 it is compositionally homogeneous and contains ≤3 modal% phenocrysts. The tuff also shows two very unusual aspects of the REE-bearing phases, monazite and the chevkinite-group minerals (CGM): (i) the presence of perrierite-(Ce) in a high-silica rhyolite, and (ii) the replacement of CGM in the stratigraphic sequence by monazite, with a subsequent return to a CGM. Evidence from CGM distribution and variations in monazite and apatite-group composition with stratigraphic height in the deposit are used to infer that prior to eruption the magma was compositionally zoned, the zonation being partially obliterated by convective overturn in the reservoir

The Weaklaw Vent, SE Scotland:Metasomatism of eruptive products by carbo-hydro-fluids of probable mantle origin

This is the author accepted manuscript. The final version is available from CUP via the DOI in this record The Weaklaw vent in SE Scotland (East Lothian coast), inferred to be Namurian, produced lava spatter and volcanic bombs. The latter commonly contained ultramafic xenoliths. All were metasomatised by carbonic fluids rich in incompatible elements. The lavas and xenoliths are inferred to have been basanites and lherzolites prior to metasomatism. The abundance and size of (carbonated) peridotite xenoliths at Weaklaw denotes unusual rapidity of magma ascent and high-energy eruption making Weaklaw exceptional in the British Isles. The lavas and xenoliths were altered subsequently by low-temperature (<200°C) carbo-hydrous fluids to carbonate, clay and quartz assemblages. A small irregular tuffisite 'dyke' that transects the ejecta is also composed dominantly of carbonates and clays. The peridotitic xenoliths are typically foliated, interpreted as originating as pre-entrainment mantle shear-planes. Analyses of the relic spinels shows them to be compositionally similar to spinels in local unaltered lherzolites from near-by basanitic occurrences. Chromium showed neither significant loss nor gain but was concentrated in a di-octahedral smectite allied to volkonskoite. It is in the complex association of smectite with other clays, chlorite and possibly fuchsite that the diverse incompatible elements are concentrated. We conclude that late Palaeozoic trans-tensional fault movement caused mantle shearing. Rapid ascent of basanite magma entrained large quantities of sheared lithospheric mantle. This was followed by ascent of an aggressive carbonate-/ hydroxyl-rich fluid causing pervasive metasomatism. The vent is unique in several ways: in its remarkable clay mineralogy and in displaying such high Cr-clays in a continental intra-plate setting; in being more productive in terms of its 'cargo' of peridotite xenoliths; in presenting an essentially un-eroded sequence of Namurian extrusives; and, not least, for giving evidence for post-eruptive, surface release of small-melt, deep-source fluids

Low-temperature zircon growth related to hydrothermal alteration of siderite concretions in Mississippian shales, Scotland

Zircon occurs in voids and cracks in phosphatic coprolites enclosed in siderite concretions in Mississippian shales near Edinburgh, Scotland. The zircon formed during hydrothermal alteration of early-diagenetic concretions and occurs as spherical aggregates of prismatic crystals, sometimes radiating. Vitrinite reflectance measurements indicate temperatures of ~270°C for the zircon-bearing concretions and the host shales. Molecular parameter values based on dibenzothiophene and phenanthrene distribution and occurrence of di- and tetra-hydro-products of polycyclic aromatic compounds suggest that the rocks experienced relatively high-temperature aqueous conditions related to hydrothermal fluids, perhaps associated with neighboring mafic intrusions. The zircon was dissolved from the concretions, transported in fluids, and reprecipitated in voids. This is the first record of the precipitation of authigenic zircon in sedimentary rock as a new phase, not as outgrowths

Wsparcie zarządzania bezpieczeństwem informacji i zarządzania ryzykiem w administracji publicznej

The chapter deals with the issue of the risk and security management process in public administration, according to the internal audit standards and their requirements. Main legal acts and standards were specified and shortly described. Specially the risk analysis process and security measures selection were emphasized. The possibility to use the software tools for the risk analysis and security measures selection support in public administration was presented. The experiment of OSCAD usage in public administration was shortly described and its results were presented. This experiment shows that the software primarily intended for IT Security Management can be used for risk management in different area as well, for example – in public administration. Some possibilities of further development of risk management supporting tools were proposedRozdział dotyczy problemów procesu zarządzania ryzykiem i zarządzania bezpieczeństwem w administracji publicznej i jednostkach sektora finansów publicznych, w odniesieniu do standardów kontroli zarządczej i ich wymagań. W artykule wymieniono i krótko opisano główne akty prawne i standardy związane z tymi tematami. Szczególnie wyróżniono proces analizy ryzyka i doboru zabezpieczeń. Przedstawiono możliwość wykorzystania narzędzi komputerowych do wsparcia procesu zarządzania ryzykiem i doboru zabezpieczeń w jednostkach administracji publicznej. Krótko opisano próbę wykorzystania do tego celu oprogramowania OSCAD. Eksperyment ten wykazał możliwość wykorzystania w obszarze administracji publicznej narzędzia, dedykowanego pierwotnie do wsparcia procesu zarządzania bezpieczeństwem informacji i ciągłością działania. Na koniec przedstawiono możliwości dalszego rozwoju narzędzi wspierających proces zarządzania ryzykiem

Introduction to sustainable development in the graphic arts industry

The article analyses strategies of sustainable development in the graphic arts industry. There are many deinitions of sustainable development, including this landmark one which first appeared in 1987: development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Sustainable development calls for a convergence between the three pillars of economic development, social equity and environmental protection. The best illustration is an equilateral triangle, divided for three triangles. Every triangle symbolizes one of pillars. If triangles are identical it means ideal proportions between the three pillars: economy, ethics and ecology. Graphic arts is a specific branch of industry. Printing industry requires special attention in view of the sustainable development because it covers three steps of production: prepress, press and postpress (very often performed in one printing house).The article analyses strategies of sustainable development in the graphic arts industry. There are many deinitions of sustainable development, including this landmark one which first appeared in 1987: development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Sustainable development calls for a convergence between the three pillars of economic development, social equity and environmental protection. The best illustration is an equilateral triangle, divided for three triangles. Every triangle symbolizes one of pillars. If triangles are identical it means ideal proportions between the three pillars: economy, ethics and ecology. Graphic arts is a specific branch of industry. Printing industry requires special attention in view of the sustainable development because it covers three steps of production: prepress, press and postpress (very often performed in one printing house)