243 research outputs found
Savignys Schüler, Bettinas Hirtenknabe, Philipp Hössli
No full text*Bettina von Arnim, »Ist Dir bange vor meiner Liebe?« Briefe an Philipp Hössli, nebst dessen Gegenbriefen und Tagebuchnotizen, hg. von Kurt Wanner, Frankfurt a.M. und Leipzig: Insel, 2. Auflage 1997, 242 S., ISBN 3-458-16798-6
*Kurt Wanner, Philipp Hössli oder die Sehnsucht nach der Aussicht auf dem Gipfel des Berges, Walservereinigung Graubünden Splügen und Verein für Bündner Kulturforschung Chur, 200
Quantifying the glacial meltwater contribution to mountainous streams using stable water isotopes: What are the opportunities and limitations?
No full textThis study aims to determine the opportunities and limitations of using stable water isotopes to quantify the glacial meltwater contribution to mountainous streams. For this purpose, three partially glaciated catchments in the Swiss Alps were selected as the study area. In the three catchments, stable isotope analysis (δ18O and δ2H) was conducted of the streams and the end-members that contribute to the stream discharge (glacial meltwater, rain, snow). The investigations revealed that the contribution of glacial meltwater to mountainous streams can be quantified using stable water isotopes if three criteria are met: (A) The snow meltwater contribution to mountainous streams must be negligible due to its highly variable stable isotope signature; (B) the groundwater input needs to be either insignificant during this snow-free period or the groundwater residence time must be short such that groundwater contribution does not delay the end-member signal arriving in the streams; and (C) the isotope signal of the glacial melt end-member needs to be distinct from the other end-members. One of the three investigated catchments fulfilled these criteria in August and September, and the glacial meltwater contribution to the mountainous streams could be estimated based on stable water isotopes. During this time period, the glacial meltwater contribution to the stream discharge corresponded to up to 85% ± 2% and to 28.7% ± 10% of the total annual discharge, respectively. This high glacial meltwater contribution demonstrates that the mountainous stream discharges in August and September will probably strongly decrease in the future due to global warming-induced deglaciation. Overall, this study demonstrates that many hydrogeological conditions need to be met so that stable water isotopes can be used to quantify the glacial meltwater contribution to mountainous streams. This highlights the challenges when using stable water isotopes for hydrograph separation and serves as a guide for future stable water isotope studies in mountainous regions
Assessing the Environmental Hazard of Using Seawater for Ore Processing at the Lasail Mine Site in the Sultanate of Oman
No full textThe Lasail mining area (Sultanate of Oman) was contaminated by acid mine drainage during the exploitation and processing of local and imported copper ore and the subsequent deposition of sulphide-bearing waste material into an unsealed tailings dump. In this arid environment, the use of seawater in the initial stages of ore processing caused saline contamination of the fresh groundwater downstream of the tailings dump. After detection of the contamination in the 1980s, different source-controlled remediation activities were conducted including a seepage water collection system and, in 2005, surface sealing of the tailings dump using an HDPE-liner to prevent further infiltration of meteoric water. We have been assessing the benefits of the remediation actions undertaken so far. We present chemical and isotopic (δ18O, δ 2H, 3H) groundwater data from a long-term survey (8–16 years) of the Wadi Suq aquifer along a 28 km profile from the tailings dump to the Gulf of Oman. Over this period, most metal concentrations in the Wadi Suq groundwater decreased below detection limits. In addition, in the first boreholes downstream of the tailings pond, the salinity contamination has decreased by 30 % since 2005. This decrease appears to be related to the surface coverage of the tailings pond, which reduces flushing of the tailings by the sporadic, but commonly heavy, precipitation events. Despite generally low metal concentrations and the decreased salinity, groundwater quality still does not meet the WHO drinking water guidelines in more than 90 % of the Wadi Suq aquifer area. The observations show that under arid conditions, use of seawater for ore processing or any other industrial activity has the potential to contaminate aquifers for decades
Russian-Chinese Trade in Kyakhta — Trade Development and Volume Indicators 1727–1861
No full textThe study looks at the trade quantification, and documents single stages of the Russian-Chinese trade exchange in Kyakhta and May-ma-chen between 1727 and 1861. It is divided into three sections. The first one deals with an appraisal of available volume indicators that relates to the exchange trading. Based on findings and confronting other analysed spheres, the author defines the basic stages of the trade development in the monitored period. What he demonstrates is that the trade was greatly affected by political and geographical factors, and the fact that both countries did not attach equal importance to it. The trade in Kyakhta had never reached extent it could have had, but fell into rapid decline as soon as an alternative, cheaper way to trade exchange between Russia and China had appeared. Yet it influenced the town and the whole region development, including culture and education spheres; in the second quarter of the 19th century it substantially contributed to Siberian economics, and in the early stage also to Russia industrialisation as it allowed Russia in economics terms to penetrate to the Far East. The final part deals with the global factors resulting in the decline, and the end of Russian-Chinese trade in Kyakhta, or replacement by other forms of trade exchange.172
Automated synapse-level reconstruction of neural circuits in the larval zebrafish brain
No full textThis Resource presents a serial block-face EM dataset of the whole larval zebrafish brain, including automated segmentation of neurons, detection of synapses and reconstruction of circuitry for visual motion processing. Dense reconstruction of synaptic connectivity requires high-resolution electron microscopy images of entire brains and tools to efficiently trace neuronal wires across the volume. To generate such a resource, we sectioned and imaged a larval zebrafish brain by serial block-face electron microscopy at a voxel size of 14 x 14 x 25 nm(3). We segmented the resulting dataset with the flood-filling network algorithm, automated the detection of chemical synapses and validated the results by comparisons to transmission electron microscopic images and light-microscopic reconstructions. Neurons and their connections are stored in the form of a queryable and expandable digital address book. We reconstructed a network of 208 neurons involved in visual motion processing, most of them located in the pretectum, which had been functionally characterized in the same specimen by two-photon calcium imaging. Moreover, we mapped all 407 presynaptic and postsynaptic partners of two superficial interneurons in the tectum. The resource developed here serves as a foundation for synaptic-resolution circuit analyses in the zebrafish nervous system
Rosenbrock time integration for unsteady flow simulations
No full textThis contribution compares the efficiency of Rosenbrock time integration schemes with ESDIRK schemes, applicable to unsteady flow and fluid-structure interaction simulations. Compared to non-linear ESDIRK schemes, the linear implicit Rosenbrock-Wanner schemes require subsequent solution of the same linear systems with different right hand sides. By solving the linear systems with the iterative solver GMRES, the preconditioner can be reused for the subsequent stages of the Rosenbrock-Wanner scheme. Unsteady flow simulations show a gain in computational efficiency of approximately factor three to five in comparison with ESDIRK.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin
Clause-linkage techniques as a symptom of discourse traditions: methodological issues and evidence from Romance languages
No full textFeature engineering for author profiling and identification: on the relevance of syntax and discourse
No full textAuthor profiling and identification are two areas of data-driven computational linguistics that have gained a lot of relevance due to their potential applications in, e.g., forensic linguistic studies, marketing analysis, and historic/literary authorship verification. Author profiling aims to identify demographic traits of the authors, while author identification aims to identify the authors themselves by searching for distinctive linguistic patterns that distinguish them. The majority of approaches in the related work tends to focus on the content of the texts. We argue that focusing on structure rather than content can be more effective. The main focus of the thesis is thus on feature engineering, the development, evaluation and application of the feature set in the context of machine learning techniques to author profiling and identification. We prove the profiling potential of syntactic and iscourse features, which achieve state-of-the-art performance in many different scenarios, especially when combined with other features.El perfilament i la identificació d’autors són camps de la lingüística computacional que han guanyat rellevància als últims anys gràcies a les seves potencials aplicacions al camp de la lingüística forense o a la verificació d’autoria de textos històrics. El perfilament d’autors té com a objectiu identificar trets demogràfics dels autors; la identificació d’autors tracta d’identificar l’autor del text. Per fer-ho, es busquen automàticament patrons lingüístics per diferenciar entre autors/trets demogràfics. La majoria de treballs anteriors, es centren en el contingut dels texts. Nosaltres argumentem que analitzar l’estructura del text pot ser una alternativa més efectiva. El focus d’aquesta tesi està per tant, al feature engineering: la extracció avaluació i utilització d’un conjunt de característiques lingüístiques amb algoritmes d’aprenentatge automàtic per a perfilar/identificar autors. Demostrem que les característiques sintàctiques i discursives són rellevants i que combinades amb altres, obtenen resultats a l’altura de l’estat de l’art.Programa de doctorat en Tecnologies de la Informació i les Comunicacion
Feature engineering for author profiling and identification: on the relevance of syntax and discourse
No full textAuthor profiling and identification are two areas of data-driven computational linguistics that have gained a lot of relevance due to their potential applications in, e.g., forensic linguistic studies, marketing analysis, and historic/literary authorship verification. Author profiling aims to identify demographic traits of the authors, while author identification aims to identify the authors themselves by searching for distinctive linguistic patterns that distinguish them. The majority of approaches in the related work tends to focus on the content of the texts. We argue that focusing on structure rather than content can be more effective. The main focus of the thesis is thus on feature engineering, the development, evaluation and application of the feature set in the context of machine learning techniques to author profiling and identification. We prove the profiling potential of syntactic and iscourse features, which achieve state-of-the-art performance in many different scenarios, especially when combined with other features.El perfilament i la identificació d’autors són camps de la lingüística computacional que han guanyat rellevància als últims anys gràcies a les seves potencials aplicacions al camp de la lingüística forense o a la verificació d’autoria de textos històrics. El perfilament d’autors té com a objectiu identificar trets demogràfics dels autors; la identificació d’autors tracta d’identificar l’autor del text. Per fer-ho, es busquen automàticament patrons lingüístics per diferenciar entre autors/trets demogràfics. La majoria de treballs anteriors, es centren en el contingut dels texts. Nosaltres argumentem que analitzar l’estructura del text pot ser una alternativa més efectiva. El focus d’aquesta tesi està per tant, al feature engineering: la extracció avaluació i utilització d’un conjunt de característiques lingüístiques amb algoritmes d’aprenentatge automàtic per a perfilar/identificar autors. Demostrem que les característiques sintàctiques i discursives són rellevants i que combinades amb altres, obtenen resultats a l’altura de l’estat de l’art.Programa de doctorat en Tecnologies de la Informació i les Comunicacion
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