144 research outputs found
Simulation der gestrahlten Emission einer Gigabit Ethernet Ăbertragungsstrecke in einem an CISPR25 angelehnten Setup
In aktuellen Fahrzeugentwicklungen spielen bildgebende Systeme wie sie fĂŒr das autonome Fahren und Fahrerassistenzsysteme benötigt werden und in das Fahrzeug eingebundene Unterhaltungselektronik eine groĂe Rolle. Um die anfallenden Datenmengen der verschiedenen Systemkomponenten zu ĂŒbertragen, setzten viele Hersteller auf die Kommunikation mittels Gigabit Ethernet. Aufgrund der hohen Ăbertragungsgeschwindigkeiten und der vielen verbauten Medienkonverter im Fahrzeug, ergeben sich hohe Anforderungen an das Bordnetz und damit verbunden an die EMV1. Um den EMV Anforderungen an die Elektronik und Ăbertragungsstrecken gerecht zu werden, wurde ein Simulationssetup gesucht, mit dem es möglich ist verschiedene Treiber, Filterbeschaltungen, Kabelvarianten und Schirmauflagen, sowie Versorgungskonzepte der beteiligen Kommunikationspartner miteinander zu vergleichen. Hierzu wurde ein an CISPR25 angelehntes Setup erstellt, mit dem die Auswirkungen der aufgezĂ€hlten Parameter auf die gestrahlte Störaussendung analysiert werden kann
The onset and solidification path of a basaltic melt by in situ differential scanning calorimetry (DSC) and ex situ investigations
The in situ differential scanning calorimetry (DSC) technique has been applied to investigate the solidification paths of a basaltic liquid. The starting glass was heated up to 1300âŠC, kept at this superliquidus temperature for 2 h and cooled at rates (âT/ât) of 7, 60, 180, 1000, and 1800âŠC/h, down to 800 and 600âŠC. Glass transition temperature (Tg), crystallization temperature (Tx_HR) and melting temperature (Tm) were measured by in situ DSC spectra on heating. Tx measured along the cooling paths (Tx_CR) shows exothermic peaks that change from a single symmetric shape (7 and 60âŠC/h) to multi-component patterns (180, 1000, and 1800âŠC/h). The recovered products characterized by field emission gun source of the scanning electron microscopy and electron probe micro-analyzer-wavelength dispersive spectrometers show a phase assemblage of spinel (sp), clinopyroxene (cpx), melilite (mel), plagioclase (plg), and glass. Moreover, crystal size distributions (CSDs) and growth rates (Gmax and GCSD) were also determined. The crystal content slightly increases from 7 to 1800âŠC/h. Faceted sp are present in all the run products with an amount always <2 area%. Cpx increases from 7 to 1800âŠC/h, changing its texture from almost faceted to dendritic between 60 and 180âŠC/h. The area% of mel follows an asymmetric Gaussian trend, while plg nucleates only at 7âŠC/h with a content <2 area%. The coupling of DSC and SEM outcomes indicate that sp nucleate first, followed by cpx and mel (and/or plg). The increment of âT/ât causes an increase of the CSD slope (m) and crystal population density per size (n0 ), as well as a decrease of the crystal size, for both cpx and sp. The log-linear CSD segments with different slopes at 7 and 60âŠC/h suggest multiple nucleation events and crystal growth by coarsening. Gmax and GCSD for cpx and sp directly measured on the actual crystallization time by DSC spectra, both increase with the increasing of âT/ât. The onset temperature of crystallization (Txi ) decreases as âT/ât increases, following an exponential trend that defines the uppermost portion of a time-transformation-temperature-like curve. This analytical model allows us to quantitatively model the kinetic crystallization paths of dry basalts
The Onset and Solidification Path of a Basaltic Melt by in situ Differential Scanning Calorimetry (DSC) and ex situ Investigations
The in situ differential scanning calorimetry (DSC) technique has been applied to investigate the solidification paths of a basaltic liquid. The starting glass was heated up to 1300°C, kept at this superliquidus temperature for 2 h and cooled at rates (ÎT/Ît) of 7, 60, 180, 1000, and 1800°C/h, down to 800 and 600°C. Glass transition temperature (Tg), crystallization temperature (Tx_HR) and melting temperature (Tm) were measured by in situ DSC spectra on heating. Tx measured along the cooling paths (Tx_CR) shows exothermic peaks that change from a single symmetric shape (7 and 60°C/h) to multi-component patterns (180, 1000, and 1800°C/h). The recovered products characterized by field emission gun source of the scanning electron microscopy and electron probe micro-analyzer-wavelength dispersive spectrometers show a phase assemblage of spinel (sp), clinopyroxene (cpx), melilite (mel), plagioclase (plg), and glass. Moreover, crystal size distributions (CSDs) and growth rates (Gmax and GCSD) were also determined. The crystal content slightly increases from 7 to 1800°C/h. Faceted sp are present in all the run products with an amount always <2 area%. Cpx increases from 7 to 1800°C/h, changing its texture from almost faceted to dendritic between 60 and 180°C/h. The area% of mel follows an asymmetric Gaussian trend, while plg nucleates only at 7°C/h with a content <2 area%. The coupling of DSC and SEM outcomes indicate that sp nucleate first, followed by cpx and mel (and/or plg). The increment of ÎT/Ît causes an increase of the CSD slope (m) and crystal population density per size (n0), as well as a decrease of the crystal size, for both cpx and sp. The log-linear CSD segments with different slopes at 7 and 60°C/h suggest multiple nucleation events and crystal growth by coarsening. Gmax and GCSD for cpx and sp directly measured on the actual crystallization time by DSC spectra, both increase with the increasing of ÎT/Ît. The onset temperature of crystallization (Txi) decreases as ÎT/Ît increases, following an exponential trend that defines the uppermost portion of a time-transformation-temperature-like curve. This analytical model allows us to quantitatively model the kinetic crystallization paths of dry basalts
Managing Phenol Contents in Crop Plants by Phytochemical Farming and BreedingâVisions and Constraints
Two main fields of interest form the background of actual demand for optimized levels of phenolic compounds in crop plants. These are human health and plant resistance to pathogens and to biotic and abiotic stress factors. A survey of agricultural technologies influencing the biosynthesis and accumulation of phenolic compounds in crop plants is presented, including observations on the effects of light, temperature, mineral nutrition, water management, grafting, elevated atmospheric CO2, growth and differentiation of the plant and application of elicitors, stimulating agents and plant activators. The underlying mechanisms are discussed with respect to carbohydrate availability, trade-offs to competing demands as well as to regulatory elements. Outlines are given for genetic engineering and plant breeding. Constraints and possible physiological feedbacks are considered for successful and sustainable application of agricultural techniques with respect to management of plant phenol profiles and concentrations
Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases
The production of peroxide and superoxide is an inevitable consequence of
aerobic metabolism, and while these particular "reactive oxygen species" (ROSs)
can exhibit a number of biological effects, they are not of themselves
excessively reactive and thus they are not especially damaging at physiological
concentrations. However, their reactions with poorly liganded iron species can
lead to the catalytic production of the very reactive and dangerous hydroxyl
radical, which is exceptionally damaging, and a major cause of chronic
inflammation. We review the considerable and wide-ranging evidence for the
involvement of this combination of (su)peroxide and poorly liganded iron in a
large number of physiological and indeed pathological processes and
inflammatory disorders, especially those involving the progressive degradation
of cellular and organismal performance. These diseases share a great many
similarities and thus might be considered to have a common cause (i.e.
iron-catalysed free radical and especially hydroxyl radical generation). The
studies reviewed include those focused on a series of cardiovascular, metabolic
and neurological diseases, where iron can be found at the sites of plaques and
lesions, as well as studies showing the significance of iron to aging and
longevity. The effective chelation of iron by natural or synthetic ligands is
thus of major physiological (and potentially therapeutic) importance. As
systems properties, we need to recognise that physiological observables have
multiple molecular causes, and studying them in isolation leads to inconsistent
patterns of apparent causality when it is the simultaneous combination of
multiple factors that is responsible. This explains, for instance, the
decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
EMV Simulationsprozess fĂŒr komplexe Kfz Systeme
EMV Simulation ist ein sehr anspruchsvolles, wertvolles und mĂ€chtiges Werkzeug fĂŒr EMV Spezialisten. Wenn dieses Werkzeug nicht nur fĂŒr einzelne individuelle Analysen, sondern auch als fester Bestandteil bei der Produktentwicklung komplexer Systeme verwendet werden soll, bedarf es einer Vielzahl an Voraussetzungen und BefĂ€higungen. Dieser Fachartikel behandelt Fragestellungen und Lösungen, wie die EMV Simulation in den Entwicklungsprozess von Kraftfahrzeugen erfolgreich integriert werden kann. Es wird diskutiert, warum die EMV Systemsimulation im Vergleich zur etablierten Crash Berechnung bei der Demokratisierung nicht mithalten kann. AnschlieĂend wird der operative Simulationsprozess beschrieben, welcher sich aus der Datenbeschaffung, Modellierung, Berechnung und Auswertung zusammensetzt. Damit der Prozess funktionieren kann, werden BefĂ€higungen benötigt. Zu den BefĂ€higungen gehört ein professionelles Datenmanagement System, eine durchgĂ€ngige Toolkette, abgestimmte synchronisierte ProjektplĂ€ne des Gesamtsystems, fest definierte SimulationslastfĂ€lle und eine durchgĂ€ngige Verifikations- und Validierungsstrategie. Wenn der Prozess definiert und die BefĂ€higungen sichergestellt sind, kann der Aufwand dem Nutzen gegenĂŒbergestellt werden, um den neuen Prozess zu bewerten
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