Der Elektromagnetische Telegraph : in den hauptstadien seiner Entwickelung und in seiner gegenwärtigen Ausbildung und Anwendung : nebst einen Anhange über den Betrieb der elektrischen Unren : ein handbuch der theoretischen und praktischen Telegraphie für Telegraphenbeamten

Taques d'òxid3rd gänzlich umgearb

Exergy analysis:Tthe effect of relative humidity, air temperature and effective clothing insulation on thermal comfort

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Hera: evidence for multiple mineralization events and remobilization in a sediment-hosted Au-Pb-Zn-Ag deposit, Central New South Wales, Australia

The Hera Au-Ag-Pb-Zn deposit of central New South Wales, Australia with a total undepleted resource of 3.6 Mt @ 3.3 g/t Au, 25 g/t Ag, 2.6% Pb and 3.8% Zn occurs on the SE margin of the Cobar Basin. It is hosted by the shallow marine Mouramba Group and overlying turbiditic Amphitheatre Group. The siltstones comprise various mixtures of quartz, plagioclase, muscovite-phengite, biotite and clinochlore, along with accessory titanite and ilmenite. The deposit comprises a number of discrete lodes which are steeply west-dipping and strike NNW. Each lode has different abundances of the main ore minerals sphalerite, galena, chalcopyrite, pyrrhotite and electrum-gold. The North Pod and Far West lenses have the most diverse mineralogy in additionally containing arsenopyrite, native silver, gudmundite, Ag-tetrahedrite, acanthite, dyscrasite, native antimony, nisbite and breithauptite. Electrum (continuous spectrum from Ag-rich to Au-rich) is associated with sulfides in the main ore lenses while native gold occurs in the host rocks along cleavages/lineations and away from the main ore. The sulfur isotope data from across the deposit indicates a magmatic source. Most of the deposit has experienced greenschist facies metamorphism with pervasive green chlorite alteration, though the North Pod differs in being distinctly Ag- and Sb-rich and has reached at least amphibolite facies metamorphism with a garnet-wollastonite-vesuvianite-tremolite assemblage. Tremolite is relatively abundant throughout most of the deposit suggesting widespread low-T skarn alteration. Cross-cutting pegmatites comprise quartz, plagioclase (labradorite-andesine) and microcline. Hydrothermal remobilization is relatively extensive and best explains the unusual Ag-Sb-As assemblages of the North Pod and Far West lodes

Explaining Models: Theoretical and Phenomenological Models and Their Role for the First Explanation of the Hydrogen Spectrum

Wilholt T. Explaining Models: Theoretical and Phenomenological Models and Their Role for the First Explanation of the Hydrogen Spectrum. Foundations of Chemistry. 2005;7(2):149-169.Traditional nomological accounts of scientific explanation have assumed that a good scientific explanation consists in the derivation of the explanandum's description from theory (plus antecedent conditions). But in more recent philosophy of science the adequacy of this approach has been challenged, because the relation between theory and phenomena in actual scientific practice turns out to be more intricate. This critique is here examined for an explanatory paradigm that was groundbreaking for 20th century physics and chemistry (and their interrelation): Bohr's first model of the atom and its explanatory relevance for the spectrum of hydrogen. First, the model itself is analysed with respect to the principles and assumptions that enter into its premises. Thereafter, the origin of the model's explanandum is investigated. It can be shown that the explained "phenomenon" is itself the product of a host of modelling accomplishments that stem from an experimental tradition related to 19th century chemistry, viz. spectroscopy. The relation between theory and phenomenon is thus mediated in a twofold way: by (Bohr's) theoretical model and a phenomenological model from spectroscopy. In the final section of the paper an account is outlined that nevertheless permits us to acknowledge this important physico-chemical achievement as a case of (nomological) explanation

Der Elektromagnetische Telegraph : in den hauptstadien seiner Entwickelung und in seiner gegenwärtigen Ausbildung und Anwendung : nebst einen Anhange über den Betrieb der elektrischen Unren : ein handbuch der theoretischen und praktischen Telegraphie für Telegraphenbeamten

Taques d'òxi

Die Spectralanalyse in ihrer Anwendung auf die Stoffe der Erde und die Natur der Himmelskörper ...

von H. Schelle