572 research outputs found
On Entangled Multi-particle Systems in Bohmian Theory
Arguments are presented to show that in the case of entangled systems there
are certain difficulties in implementing the usual Bohmian interpretation of
the wave function in a straightforward manner. Specific examples are given.Comment: 7 page
Petrogenesis of Mafic to Felsic Lavas from the Oligocene Siebengebirge Volcanic Field (Germany): Implications for the Origin of Intracontinental Volcanism in Central Europe
Magmatism in the Cenozoic Central European Volcanic Province (CEVP) has been related to two geodynamic scenarios, either extensional tectonics in the north Alpine realm or upwelling of deep mantle material. The Oligocene (∼30-19 Ma) Siebengebirge Volcanic Field (SVF) is a major part of the German portion of the CEVP and consists of erosional remnants of mafic to felsic volcanic edifices. It covers an area of ∼35 km (NW-SE) by ∼25 km (SW-NE) with eruptive centres concentrated near the eastern shore of the Rhine river in the vicinity of the city of Bonn. Mafic rocks in the SVF comprise strongly SiO2-undersaturated basanites to alkaline basalts. Occurrences of alkaline basalts are confined to an inner NW-SE-striking zone, whereas the more SiO2-undersaturated basanites dominate the western and eastern periphery of the SVF. Radiogenic isotope compositions (87Sr/86Sr 0·70335-0·70371; εNd +3·1 to +4·5; εHf +6·5 to +8·0; 206Pb/204Pb 19·46-19·69; 207Pb/204Pb 15·63-15·66; 208Pb/204Pb 39·34-39·62) indicate a common asthenospheric mantle end-member with HIMU-like characteristics for all mafic rocks, similar to the European Asthenospheric Reservoir (EAR). A lithospheric mantle source component with a residual K-bearing phase (phlogopite or amphibole) is inferred from negative K anomalies. Incompatible trace element modelling indicates that melting took place in the spinel-garnet transition zone with low degrees of melting at higher pressures generating the basanitic magmas (LaN/YbN = 20-25), whereas the alkaline basalts (LaN/YbN = 14-18) are the result of higher melting degrees at shallower average melting depths. Differentiation of basanitic primary melts generated tephritic to tephriphonolitic magmas that, for instance, erupted at the Löwenburg Volcanic Complex in the central SVF. Latites and trachytes, such as the prominent Drachenfels and Wolkenburg protrusions, are more common in the central portion of the SVF. These compositions originate from parental alkaline basaltic melts. All differentiated samples show evidence for crustal contamination, possibly with lower- to mid-crustal material comprising mafic granulites as found in Eifel basalt xenoliths and metapelites. Based on the spatial and temporal distribution of the various volcanic rock types, a model for the temporal evolution of the SVF can be proposed. During the initial phase of volcanism, low-degree basanitic melts were generated as a result of decompression following tectonic rifting and formation of the Cologne Embayment, a northward extension of the Rhine Graben. In a second stage, alkali basalts were generated at shallower depths and higher degrees of melting as a result of continued lithospheric thinning and passive upwelling of asthenospheric mantle. These conclusions strengthen previous models suggesting that intraplate volcanism in Central Europe is directly linked to regional lithospheric thinning and asthenospheric upwelling. Overall, the SVF constitutes an exceptionally well-preserved magmatic assemblage to illustrate these tectono-magmatic relationship
Ordinal pattern dependence as a multivariate dependence measure
In this article, we show that the recently introduced ordinal pattern
dependence fits into the axiomatic framework of general multivariate dependence
measures. Furthermore, we consider multivariate generalizations of established
univariate dependence measures like Kendall's , Spearman's and
Pearson's correlation coefficient. Among these, only multivariate Kendall's
proves to take the dynamical dependence of random vectors stemming from
multidimensional time series into account. Consequently, the article focuses on
a comparison of ordinal pattern dependence and multivariate Kendall's .
To this end, limit theorems for multivariate Kendall's are established
under the assumption of near epoch dependent, data-generating time series. We
analyze how ordinal pattern dependence compares to multivariate Kendall's
and Pearson's correlation coefficient on theoretical grounds.
Additionally, a simulation study illustrates differences in the kind of
dependencies that are revealed by multivariate Kendall's and ordinal
pattern dependence
EMDR und VT in der Behandlung von Traumafolgestörungen – Charakteristika und Kombinationsmöglichkeiten
Fokus dieses Beitrages ist, aus der konkreten Praxis mit Eye Movement Desensitization and Reprocessing (EMDR) und traumafokussierter Verhaltens-therapie (TF-VT) / Kognitiver Verhaltenstherapie heraus eine persönliche Einschätzung optimaler Indikationsstellungen für die eine oder andere Methode beziehungsweise vor allem gute Kombinationsmöglichkeiten im Sinne der besten Effekte primär für die Betroffenen von Traumafolgestörungen Typ I darzustellen.Dazu sollen zunächst einmal einige grundsätzliche Vorbemerkungen über beide Ansätze erfolgen, danach ein Vergleich im Überblick in den wichtigsten Bereichen. Darauf folgend findet sich eine Erläuterung der wichtigsten Wirkmechanismen und einige Überlegungen zu Kombinationsmöglichkeiten im Hinblick auf einen »added value« für die Betroffenen. Der Beitrag endet mit zwei illustrierenden Beispielen. Schlagwörter: EMDR, Traumatherapie, Kognitiv Behaviorale Therapie, Typ I-Typ II Traumatisierung, Psychoedukation, KomorbiditätThis article is focusing on indications for senseful combinations between trauma-focused (TF-BT and cognitive behaviour therapy (CBT) and EMDR primarily for patients suffering from type I traumatisation. These reflections express personal thoughts and experiences from practical work with both methods. Firstly there will be general remarks concerning both therapeutical methods, then a comparison between both methods in some crucial aspects followed by indications for combinations vice versa. Finally two clinical examples will illustrate the theoretical and practical remarks. Key words: EMDR, traumatherapy, CBT, Type I, Type II traumatisation, psychoeducation, comorbidity Neben den zahlreichen und breitgefächerten Beiträgen in diesem Sonderheft zum Thema »Arbeit mit Menschen, die unter den Folgen von psychischer Traumatisierung leiden«, soll dieser methodenspezifische Beitrag – EMDR und VT vor allem in der Behandlung von Traumafolgestörungen Typ I – die Palette ergänzen
Mass-independent Sn isotope fractionation and radiogenic 115Sn in chondrites and terrestrial rocks
Tin has ten stable isotopes, providing the opportunity to investigate and discriminate nucleosynthetic isotope anomalies from mass-dependent and mass-independent isotope fractionation. Novel protocols for chemical separation (based on TBP-resin) and MC-ICP-MS analyses are reported here for high precision Sn isotope measurements on terrestrial rocks and chondrites. Relative to the Sn reference standard (NIST SRM 3161a), terrestrial basalts and chondrites show isotope patterns that are consistent with mass-dependent and mass-independent isotope fractionation processes as well as with 115Sn radiogenic ingrowth from 115In. Two different mass-independent isotope effects are identified, namely the nuclear volume (or nuclear field shift) and the magnetic isotope effect. The magnetic isotope effect dominates in the two measured ordinary chondrites, while repeated analyses of the carbonaceous chondrite Murchison (CM2) display a pattern consistent with a nuclear volume effect. Terrestrial basalts show patterns that are compatible with a mixture of nuclear volume and magnetic isotope effects. The ultimate origin of the isotope fractionation is unclear but a fractionation induced during sample preparation seems unlikely because different groups of chondrites show distinctly different patterns, hence pointing towards natural geo/cosmochemical processes. Only the carbonaceous chondrite Murchison (CM2) shows a Sn isotope pattern similar to what expected for nucleosynthetic variations. However, this pattern is better reproduced by nuclear volume effects. Thus, after considering mass-independent and mass-dependent effects, we find no evidence of residual nucleosynthetic anomalies, in agreement with observations for most other elements with similar half-mass condensation temperatures. Most chondrites show a deficit in 115Sn/120Sn (typically −150 to −200 ppm) relative to terrestrial samples, with the exception of one ordinary chondrite that displays an excess of about +250 ppm. The 115Sn/120Sn data correlate with In/Sn, being consistent with the β− decay of 115In over the age of the solar system. This represents the first evidence of the 115In-115Sn decay system in natural samples. The radiogenic 115Sn signature of the BSE derives from a suprachondritic In/SnBSE, which reflects preferential partitioning of Sn into the Earth's core
Method to Suppress Isobaric and Polyatomic Interferences for Measurements of Highly Siderophile Elements in Desilicified Geological Samples
Sample decomposition using inverse aqua regia at elevated temperatures and pressures (e.g., Carius tube or high‐pressure asher) is the most common method used to extract highly siderophile elements (HSEs: Ru, Rh, Pd, Re, Os, Ir, Pt and Au) from geological samples. Recently, it has been recognised that additional HF desilicification is necessary to better recover HSEs, potentially contained within silicate or oxide minerals in mafic samples, which cannot be dissolved solely by inverse aqua regia. However, the abundance of interfering elements tends to increase in the eluent when conventional ion‐exchange purification procedures are applied to desilicified samples. In this study, we developed an improved purification method to determine HSEs in desilicified samples. This method enables the reduction of the ratios of isobaric and polyatomic interferences, relative to the measured intensities of HSE isotope masses, to less than a few hundred parts per million. Furthermore, the total procedural blanks are either comparable to or lower than conventional methods. Thus, this method allows accurate and precise HSE measurements in mafic and ultramafic geological samples, without the need for interference corrections. Moreover, the problem of increased interfering elements, such as Zr for Pd and Cr for Ru, is circumvented for the desilicified samples
Using photo-activated localization microscopy (PALM) for imaging fluorophore-doped photoresists
Photoresists play a key role in the photolithographic process being necessary to print the structure layout of dies of microchips. Following Moore’s law leads to ever smaller assemblies reaching the single-digit nanometer range. Typical methods for quality assurance are scatterometry and atomic force microscopy facing challenges and disadvantages. Since overcoming the Abbe limit via superresolution techniques fluorescence microscopy can be another approach. This article describes the measurement analyses done with PALM/STORM on lithographical produced samples of positive resist doped with Atto 565. Lines with 200 nm thickness and equal spacing were studied. Thereby, ThunderSTORM provided better results than QuickPALM for data analysis. For the first experiment, using a permanently switched on 405 nm laser beam with low intensity shows the best resolution results. A rotating lambda half-wave plate in the second experiment leads to a slight increase of data quality. Further studies combining these two approaches will be carried out
Aluminum-26 Enrichment in the Surface of Protostellar Disks Due to Protostellar Cosmic Rays
The radioactive decay of aluminum-26 (Al) is an important heating
source in early planet formation. Since its discovery, there have been several
mechanisms proposed to introduce Al into protoplanetary disks, primarily
through contamination by external sources. We propose a local mechanism to
enrich protostellar disks with Al through irradiation of the
protostellar disk surface by cosmic rays accelerated in the protostellar
accretion shock. We calculate the Al enrichment, [Al/Al],
at the surface of the protostellar disk in the inner AU throughout the
evolution of low-mass stars, from M-dwarfs to proto-Suns. Assuming constant
mass accretion rates, , we find that irradiation by MeV cosmic rays
can provide significant enrichment on the disk surface if the cosmic rays are
not completely coupled to the gas in the accretion flow. Importantly, we find
that low accretion rates, M yr, are able
to produce canonical amounts of Al, . These accretion rates are experienced at the
transition from Class I- to Class II-type protostars, when it is assumed that
calcium-aluminum-rich inclusions condense in the inner disk. We conclude that
irradiation of the inner disk surface by cosmic ray protons accelerated in
accretion shocks at the protostellar surface may be an important mechanism to
produce Al. Our models show protostellar cosmic rays may be a viable
model to explain the enrichment of Al found in the Solar System.Comment: Accepted to ApJ, in pres
FAA to Test Ability of Foam Beds to Stop Airplanes in Emergencies; UD Researchers Work to Help Develop the Airplane of the Future
Feature leads for the media: Based on computer simulations developed by University of Dayton researchers, the Federal Aviation Administration will conduct tests of foam beds for their ability to stop airplanes without harming passengers; also, UD\u27s Mechanical and Aerospace Engineering Department is conducting research to develop an aerospace plane designed to fly eight times faster than an existing Air Force plane
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