594 research outputs found

    Transport Phenomena and Structuring in Shear Flow of Suspensions near Solid Walls

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    In this paper we apply the lattice-Boltzmann method and an extension to particle suspensions as introduced by Ladd et al. to study transport phenomena and structuring effects of particles suspended in a fluid near sheared solid walls. We find that a particle free region arises near walls, which has a width depending on the shear rate and the particle concentration. The wall causes the formation of parallel particle layers at low concentrations, where the number of particles per layer decreases with increasing distance to the wall.Comment: 14 pages, 14 figure

    Clastos con calcimicrobios y arqueociatos procedentes de depósitos marinos del talud de la Formación cámbrica del Monte Wegener, Coats Land, Cordillera de Shackleton Antártida

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    The carbonate clasts from the Mount Wegener Formation provide sedimentological, diagenetic and palaeontological evidences of the destruction and resedimentation of a hidden/unknown Cambrian carbonate shallow-water record at the Coats Land region of Antarctica. This incomplete mosaic could play a key role in comparisons and biostratigraphic correlations between the Cambrian record of the Transantarctic Mountains, Ellsworth-Whitmore block and Antarctic Peninsula at the Antarctica continent. Moreover, it represents a key record in future palaeobiogeographic reconstructions of South Gondwana based on archaeocyathan assemblages.Los clastos carbonatados de la Formación del Monte Wegener proporcionan evidencias sedimentológicas, diagenéticas y paleontológicas de la destrucción y resedimentación de un registro carbonatadoo cámbrico oculto/no conocido en aguas someras de la región de Coats Land en la Antártida. Este mosaico incompleto podría jugar un papel clave en las comparaciones y correlaciones bioestratigráficas entre el registro cámbrico de las Montañas Transantárticas, el bloque Ellsworth-Whitmore y la Península Antártica del continente antártico. Además, representa un registro clave en las futuras reconstrucciones paleobiogeográficas de Gondwana meridional basadas en asociaciones de arqueociatos

    Telaprevir-based triple-therapy in patients with chronic hepatitis C in Germany: a 12-week interim analysis of real-life data

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    Telaprevir (TVR)-based triple therapy in patients (pts) with chronic hepatitis C (HCV) in daily practice in Germany is investigated in this non-interventional study. Aims are the evaluation of the implementation of futility rules, as well as safety and efficacy of TVR-based therapy. This prospective, multi-center study investigates TVR-based therapy in therapy-naïve and pretreated pts with genotype 1 chronic HCV in Germany, including pts with HIV co-infection. Patients are treated with a combination of TVR, ribavirin and peg-interferon. This interim analysis includes data from the first 100 pts (12.5% of the planned total) at 32 sites completing 12 weeks (W) of treatment. 66% of pts were pretreated for HCV. 36.4% of pts with pre-treatment were prior relapsers and 30.3% null or partial responders. Cirrhosis was present in 11% of all pts at baseline. HCV RNA levels below 800.000 IU/ml at baseline were present in 50% of pts. 67% of pts showed rapid virological response (RVR, undetectable HCV RNA at W4). Adherence to the futility rule (treatment stop if HCV-RNA>1000 IU/ml at W4) was 100% (N=9). At W12, 91.4% of pts had undetectable HCV RNA. 57.7% of therapy-naïve pts and 86.4% of previous relapsers were HCV-RNA negative at both W4 and 12 (70.8% in total). Only one patient achieving RVR at W4 suffered a virologic breakthrough. Nearly all pts (99%) had adverse events (AE) during the first 12W, 6% reported serious adverse events (SAE). AEs were mostly mild (63.9%) or moderate (34.6%) and frequently mentioned dry skin/pruritus (54%), gastrointestinal disorders (48%), anorectal discomfort (30%), rash (29%) and anemia (23%). Rash was mostly rated as mild or moderate (97.1%). An Hb decrease<12 g/dl (female) or<13 g/dl (male) was reported in 87% of pts. Mean Hb levels decreased from 14.8 g/dl at baseline to 10.6 g/dl at W12; Hb levels<8.5 g/dl at any time within the first 12W of treatment were present in 11% of anemia cases and 6.6% required transfusion. Only one patient received erythropoietin treatment. 2 cases each of anemia and rash were considered as SAE. These interim results suggest that TVR-based triple-therapy is efficient against GT1 chronic hepatitis C in a real life setting. Adherence to futility rules was confirmed in all patients. As observed in clinical trials, adverse events were reported frequently, including anemia and rash. As more data become available, results will be updated

    Apparent elongational yiel stress of soft matter

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    The role of sea-level change and marine anoxia in the Frasnian-Famennian (Late Devonian) mass extinction

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    Johnson et al. (Johnson, J.G., Klapper, G., Sandberg, C.A., 1985. Devonian eustatic fluctuations in Euramerica. Geological Society of America Bulletin 96, 567–587) proposed one of the first explicit links between marine anoxia, transgression and mass extinction for the Frasnian–Famennian (F–F, Late Devonian) mass extinction. This cause-and-effect nexus has been accepted by many but others prefer sea-level fall and cooling as an extinction mechanism. New facies analysis of sections in the USA and Europe (France, Germany, Poland), and comparison with sections known from the literature in Canada, Australia and China reveal several high-frequency relative sea-level changes in the late Frasnian to earliest Famennian extinction interval. A clear signal of major transgression is seen within the Early rhenana Zone (e.g. drowning of the carbonate platform in the western United States). This is the base of transgressive–regressive Cycle IId of the Johnson et al. (Johnson, J.G., Klapper, G., Sandberg, C.A., 1985. Devonian eustatic fluctuations in Euramerica. Geological Society of America Bulletin 96, 567–587) eustatic curve. This was curtailed by regression and sequence boundary generation within the early linguiformis Zone, recorded by hardground and karstification surfaces in sections from Canada to Australia. This major eustatic fall probably terminated platform carbonate deposition over wide areas, especially in western North America. The subsequent transgression in the later linguiformis Zone, recorded by the widespread development of organic-rich shale facies, is also significant because it is associated with the expansion of anoxic deposition, known as the Upper Kellwasser Event. Johnson et al.'s (Johnson, J.G., Klapper, G., Sandberg, C.A., 1985. Devonian eustatic fluctuations in Euramerica. Geological Society of America Bulletin 96, 567–587) original transgression-anoxia–extinction link is thus supported, although some extinction losses of platform carbonate biota during the preceeding regression cannot be ruled out. Conodont faunas suffered major losses during the Upper Kellwasser Event, with deep-water taxa notably affected. This renders unreliable any eustatic analyses utilising changes in conodont biofacies. Claims for a latest Frasnian regression are not supported, and probably reflect poor biostratigraphic dating of the early linguiformis Zone sequence boundary

    Real-time benefit assessment in production of fiber reinforced polymers (FRPs) - Implementation of Industry 4.0 in benefit assessment

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    • Introduction • Motivation • Concept of the smart-work-station (SWS) • Realization of SWS • Data collection in SWS • Data processing by SWS • Eco-efficiency assessment model (EEAM) • Process modeling in EEAM • Process assessment by EEAM • Implementation of SWS • Outloo

    A screen-printing method for manufacturing of current collectors for structural batteries

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    Structural carbon fibre composite batteries are a type of multifunctional batteries that combine the energy storage capability of a battery with the load-carrying ability of a structural material. To extract the current from the structural battery cell, current collectors are needed. However, current collectors are expensive, hard to connect to the electrode material and add mass to the system. Further, attaching the current collector to the carbon fibre electrode must not affect the electrochemical properties negatively or requires time-consuming, manual steps. This paper presents a proof-of-concept method for screen-printing of current collectors for structural carbon fibre composite batteries using silver conductive paste. Current collectors are screen-printed directly on spread carbon fibre tows and a polycarbonate carrier film. Experimental results show that the electrochemical performance of carbon fibre vs lithium metal half-cells with the screen-printed collectors is similar to reference half-cells using metal foil and silver adhered metal-foil collectors. The screen-printed current collectors fulfil the requirements for electrical conductivity, adhesion to the fibres and flexible handling of the fibre electrode. The screen-printing process is highly automatable and allows for cost-efficient upscaling to large scale manufacturing of arbitrary and complex current collector shapes. Hence, the screen-printing process shows a promising route to realization of high performing current collectors in structural batteries and potentially in other types of energy storage solutions

    Covariant Balance Laws in Continua with Microstructure

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    The purpose of this paper is to extend the Green-Naghdi-Rivlin balance of energy method to continua with microstructure. The key idea is to replace the group of Galilean transformations with the group of diffeomorphisms of the ambient space. A key advantage is that one obtains in a natural way all the needed balance laws on both the macro and micro levels along with two Doyle-Erickson formulas

    Sequence stratigraphy, basin morphology and sea-level history for the Permian Kapp Starostin Formation of Svalbard, Norway

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    Based on seven measured sections from Svalbard, the marine strata of the Permian Kapp Starostin Formation are arranged into seven transgressive–regressive sequences (TR1–TR7) of c. 4–5 Ma average duration, each bound by a maximum regressive surface. Facies, including heterozoan-dominated limestones, spiculitic cherts, sandstones, siltstones and shales, record deposition within inner, middle and outer shelf areas. The lowermost sequence, TR1, comprises most of the basal Vøringen Member, which records a transgression across the Gipshuken Formation following a hiatus of unknown duration. Temperate to cold, storm-dominated facies established in inner to middle shelf areas between the latest Artinskian and Kungurian. Prolonged deepening during sequences TR2 and TR3 was succeeded by a long-term shallowing-upward trend that lasted until the latest Permian (TR4–TR7). A major depocentre existed in central and western Spitsbergen while to the north, Dickson Land remained a shallow platform, leading to a shallow homoclinal ramp in NE Spitsbergen and Nordaustlandet. The Middle Permian extinction (late Capitanian) is recorded near the base of TR6 in deeper parts of the basin only; elsewhere this sequence is not recorded. Likewise the youngest sequence, TR7, extending to the upper formational contact of latest Permian age, is found only in the basin depocentre. Comparison with age-equivalent strata in the Sverdrup Basin of Canada reveals a remarkably similar depositional history, with, for example, two (third-order) sea-level cycles recorded in the Late Permian of both regions, in keeping with the global record. Sequence stratigraphy may therefore be a powerful correlative tool for onshore and offshore Permian deposits across NW Pangaea
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