107 research outputs found

    Application of direct-inverse techniques to airfoil analysis and design

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    The direct-inverse technique was developed into a numerical method, called TRANDES, that is suitable for the analysis and design of subsonic and transonic airfoils and for the evaluation of design concepts. A general description of the method is given and its application to a design analysis type of problem is demonstrated. A usage of the method for the low speed high lift case is discussed

    Introduction : the price-stability target in the Eurozone and the European Debt Crisis (Forum)

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    U-Pb geochronology and petrogenesis of peraluminous granitoids from northern Indian plate in NW Pakistan: Andean type orogenic signatures from the early Paleozoic along the northern Gondwana

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThe pre-Himalayan peraluminous magmatic event along the northern margin of Indian plate in north-western Pakistan has been investigated leading to a correlation with the magmatic evolution in other Himalayan and northern Gondwana regions. The two mica granites from Utla and Mansehra regions of NW Pakistan are dominantly megacrystic, strongly peraluminous (A/CNK > 1.1) and intruded by aplitic dykes and quartz rich veins. U-Pb zircon dating by SIMS reveals their emplacement during the early Paleozoic, ranging from 476 Ma to 480 Ma. These granites are enriched in light rare-earth elements (LREEs) and show similar REE patterns with negative Eu anomalies. Geochemical modelling indicates that these granites were derived mainly from the partial melting of pelitic sources followed by the evolution of melt via fractional crystallization of feldspars, biotite, muscovite, apatite, and/or zircon, with the aplite dykes representing the very last fractionation product. Based on their compositions, source rock characteristics and U-Pb geochronology, we assign these to the regional association of other Cambro-Ordovician granitoids from the Himalayas and northern Gondwana terranes. Due to these similarities alongside other metamorphic, stratigraphic and geochemical evidence, an early Paleozoic Andean-type orogenic event is proposed for the genesis of these granitoids where the process could have been initiated by the subduction of the Proto-Tethys oceanic lithosphere beneath the northern Gondwana continental margin.The principal author acknowledges the financial assistance provided by the Commonwealth Scholarship Commission, United Kingdom

    Massive sulfide Zn deposits in the Proterozoic did not require euxinia

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    Our most important Zn resources occur within clastic-dominated (CD-type) deposits, which are located in a small number of Proterozoic and Phanerozoic sedimentary basins. The most common model for CD-type mineralisation involves sedimentary exhalative (SEDEX) processes, i.e. the venting of metal bearing fluids into a restricted, anoxic H2S-bearing (euxinic) water column. In the Carpentaria Zn Province (Australia), multiple world class deposits are hosted in Proterozoic (1.6 Ga) stratigraphy, where models of the ancient sulfur cycle have also been developed. Focusing on the most recent discovery – the Teena deposit – we report bulk rock and isotopic data (δ34Spyrite values) that provide information on the sulfur cycle during the diagenetic and hydrothermal evolution of the Teena sub-basin. In contrast to the SEDEX model, intervals containing abundant pyrite with highly positive δ34S values (>25 ‰) correspond with euxinic conditions that developed due to high organic loading (i.e. productivity) and not basin restriction. This basin wide feature, which can also be mistaken as a hydrothermal pyrite halo, is genetically unrelated to the subsequent hydrothermal mineralisation that formed beneath the palaeo-seafloor. The formation of CD-type deposits in the Proterozoic does not, therefore, require euxinic conditions

    Abolishing borrower privileges for European governments

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    Der wissenschaftliche Beirat beim Bundesfinanzministerium hat jüngst in einer Stellungnahme darauf aufmerksam gemacht, dass die gegenwärtige Finanzordnung in der Europäischen Währungsunion dem Staat in seiner Eigenschaft als Schuldner besondere Privilegien einräumt. Die Autoren geben einen kurzen Überblick über diese Privilegien, diskutieren die daraus resultierenden Probleme und zeigen die Notwendigkeit ihres Abbaus auf.Even though governments usually enjoy favourable borrowing conditions, the current financial system in Europe grants special privileges to government debt. This involves capital requirements in banking regulation, ECB policies, intergovernmental guarantees, etc. The paper gives a short outline of the privileges, discusses their justifi cation and highlights problems

    Integrated stratigraphy and 40Ar/39Ar chronology of the Early to Middle Miocene Upper Freshwater Molasse in eastern Bavaria (Germany)

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    A detailed integrated stratigraphic study was carried out on middle Miocene fluvial successions of the Upper Freshwater Molasse (OSM) from the North Alpine Foreland Basin, in eastern Bavaria, Germany. The biostratigraphic investigations yielded six new localities thereby refining the OSM biostratigraphy for units C to E (sensu; Heissig, Actes du Congres BiochroM'1997) and further improving biostratigraphic correlations between the different sections throughout eastern Bavaria. Radioisotopic ages of 14.55 ± 0.19 and 14.88 ± 0.11 Ma have been obtained for glass shards from the main bentonite horizon and the Ries impactite: two important stratigraphic marker beds used for confirming our magnetostratigraphic calibration to the Astronomical Tuned Neogene Time Scale (ATNTS04; Lourens et al. in Geologic Time Scale 2004, Cambridge University Press, 2004). Paleomagnetic analysis was performed using alternating field (AF) and thermal (TH) demagnetization methods. The AF method revealed both normal and reverse polarities but proofs to yield unreliable ChRM directions for the Puttenhausen section. Using the biostratigraphic information and radioisotopic ages, the magnetostratigraphic records of the different sections are tentatively correlated to the Astronomical Tuned Neogene Time Scale (ATNTS04; Lourens et al. in Geologic Time Scale 2004, Cambridge University Press, 2004). This correlation implies that the main bentonite horizon coincides to chron C5ADn, which is corroborated by its radioisotopic age of 14.55 Ma, whereas the new fossil locality Furth 460, belonging to OSM unit E, probably correlates to chron C5Bn.1r. The latter correlation agrees well with the Swiss Molasse locality Frohberg. Correlations of the older sections are not straightforward. The Brock horizon, which comprises limestone ejecta from the Ries impact, possibly correlates to C5ADr (14.581 ± 14.784 Ma), implying that, although within error, the radioisotopic age of 14.88 ± 0.11 Ma is somewhat too old. The fossil localities in Puttenhausen, belonging to the older part of OSM unit C, probably coincide with chron C5Cn.2n or older, which is older than the correlations established for the Swiss Molasse. © Springer-Verlag 2007

    Protocol for a Systematic Review on the Effectiveness of Interventions to Reduce Exposure to Occupational Solar UltraViolet Radiation (UVR) Among Outdoor Workers

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    Background: Solar UltraViolet Radiation (UVR) is considered the most relevant occupational carcinogenic exposure in terms of the number of workers exposed (i.e., outdoor workers) and UVR-induced skin cancers are among the most frequent types of occupational cancers worldwide. This review aims to collect and evaluate all the available preventive interventions conducted on outdoor workers to reduce their solar UVR related risk, with the final purpose of reducing the burden of occupational skin cancers for outdoor workers. Methods: We will search the following databases for peer-reviewed original research published: MEDLINE (through PubMed), Scopus, and EMBASE. We will include only interventional studies, both randomized and non-randomized, with an adequate comparison group, therefore excluding cross-sectional studies, as well as case-reports/series, reviews, and letters/comments. The systematic review will adhere to the “Preferred Reporting Items for Systematic reviews and Meta-Analyses” (PRISMA) guidelines for reporting systematic reviews. After the literature search, studies to be included will be independently reviewed by two Authors, first based on title and abstract, then based on the full text, according to the inclusion criteria. Conflicts will be solved by a third Author. Two authors will independently extract the required data from included studies and perform quality assessment according to the relevant domain for Risk of Bias assessment proposed by the Cochrane collaboration group. In case of sufficient homogeneity of interventions and outcomes evaluated, results from subgroups of studies will be pooled together in a meta-analysis. Discussion: Following the principles for the evaluation of interventions for cancer prevention established by the International Agency for Research on Cancer, this systematic review will investigate the effectiveness of the interventions, and consequently it will provide reliable indications for the actual reduction of skin cancer incidence in outdoor workers

    A geoneutrino experiment at Homestake

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    A significant fraction of the 44TW of heat dissipation from the Earth's interior is believed to originate from the decays of terrestrial uranium and thorium. The only estimates of this radiogenic heat, which is the driving force for mantle convection, come from Earth models based on meteorites, and have large systematic errors. The detection of electron antineutrinos produced by these uranium and thorium decays would allow a more direct measure of the total uranium and thorium content, and hence radiogenic heat production in the Earth. We discuss the prospect of building an electron antineutrino detector approximately 700m^3 in size in the Homestake mine at the 4850' level. This would allow us to make a measurement of the total uranium and thorium content with a statistical error less than the systematic error from our current knowledge of neutrino oscillation parameters. It would also allow us to test the hypothesis of a naturally occurring nuclear reactor at the center of the Earth.Comment: proceedings for Neutrino Sciences 2005, submitted to Earth, Moon, and Planet

    Seamounts off the West Antarctic margin: A case for non-hotspot driven intraplate volcanism

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    Highlights: • Marie Byrd Seamounts (MBS) formed off Antarctica at 65-56 Ma in an extensional regime • MBS originate from HIMU-type mantle attached at the base of the Antarctic lithosphere • Continental insulation flow transferred HIMU mantle into the oceanic mantle New radiometric age and geochemical data of volcanic rocks from the guyot-type Marie Byrd Seamounts (MBS) and the De Gerlache Seamounts and Peter I Island (Amundsen Sea) are presented. 40Ar/39Ar ages of the shield phase of three MBS are Early Cenozoic (65 to 56 Ma) and indicate formation well after creation of the Pacific-Antarctic Ridge. A Pliocene age (3.0 Ma) documents a younger phase of volcanism at one MBS and a Pleistocene age (1.8 Ma) for the submarine base of Peter I Island. Together with published data, the new age data imply that Cenozoic intraplate magmatism occurred at distinct time intervals in spatially confined areas of the Amundsen Sea, excluding an origin through a fixed mantle plume. Peter I Island appears strongly influenced by an EMII type mantle component that may reflect shallow mantle recycling of a continental raft during the final breakup of Gondwana. By contrast the Sr-Nd-Pb-Hf isotopic compositions of the MBS display a strong affinity to a HIMU type mantle source. On a regional scale the isotopic signatures overlap with those from volcanics related to the West Antarctic Rift System, and Cretaceous intraplate volcanics in and off New Zealand. We propose reactivation of the HIMU material, initially accreted to the base of continental lithosphere during the pre-rifting stage of Marie Byrd Land/Zealandia to explain intraplate volcanism in the Amundsen Sea in the absence of a long-lived hotspot. We propose continental insulation flow as the most plausible mechanism to transfer the sub-continental accreted plume material into the shallow oceanic mantle. Crustal extension at the southern boundary of the Bellingshausen Plate from about 74 to 62 Ma may have triggered adiabatic rise of the HIMU material from the base of Marie Byrd Land to form the MBS. The De Gerlache Seamounts are most likely related to a preserved zone of lithospheric weakness underneath the De Gerlache Gravity Anomaly

    Composition and evolution of the melts erupted in 1996 at Karymskoe Lake, Eastern Kamchatka: Evidence from inclusions in minerals

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    The powerful eruption in the Akademii Nauk caldera on January 2, 1996, marked a new activity phase of Karymsky volcano and became a noticeable event in the history of modern volcanism in Kamchatka. The paper reports data obtained by studying more than 200 glassy melt inclusions in phenocrysts of olivine (Fo82–72), plagioclase (An92–73), and clinopyroxene (Mg# 83–70) in basalts of the 1996 eruption. The data were utilized to estimate the composition of the parental melt and the physicochemical parameters of the magma evolution. According to our data, the parental melt corresponded to low magnesian, highly aluminous basalt (SiO2 = 50.2 wt %, MgO = 5.6 wt %, Al2O3 = 17 wt %) of the mildly potassic type (K2O = 0.56 wt %) and contained much dissolved volatile components (H2O = 2.8 wt %, S = 0.17 wt %, and Cl = 0.11 wt %). Melt inclusions in the minerals are similar in chemical composition, a fact testifying that the minerals crystallized simultaneously with one another. Their crystallization started at a pressure of approximately 1.5 kbar, pro ceeded within a narrow temperature range of 1040 ± 20°C, and continued until a nearsurface pressure of approximately 100 bar was reached. The degree of crystallization of the parental melt during its eruption was close to 55%. Massive crystallization was triggered by H2O degassing under a pressure of less than 1 kbar. Magma degassing in an open system resulted in the escape of 82% H2O, 93% S, and 24% Cl (of their initial contents in the parental melt) to the fluid phase. The release of volatile compounds to the atmosphere during the eruption that lasted for 18 h was estimated at 1.7 × 106 t H2O, 1.4 × 105 t S, and 1.5 × 104 t Cl. The concen trations of most incompatible trace elements in the melt inclusions are close to those in the rocks and to the expected fractional differentiation trend. Melt inclusions in the plagioclase were found to be selectively enriched in Li. The Lienriched plagioclase with melt inclusions thought to originate from cumulate layers in the feeding system beneath Karymsky volcano, in which plagioclase interacted with Lirich melts/brines and was subsequently entrapped and entrained by the magma during the 1996 eruption
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