Technische Universität Darmstadt

About: Technische Universität Darmstadt is a education organization based out in Darmstadt, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 17316 authors who have published 40619 publications receiving 937916 citations. The organization is also known as: Darmstadt University of Technology & University of Darmstadt.

Neutrino-driven winds in the aftermath of a neutron star merger: nucleosynthesis and electromagnetic transients

Abstract: We present a comprehensive nucleosynthesis study of the neutrino-driven wind in the aftermath of a binary neutron star merger. Our focus is the initial remnant phase when a massive central neutron star is present. Using tracers from a recent hydrodynamical simulation, we determine total masses and integrated abundances to characterize the composition of unbound matter. We find that the nucleosynthetic yields depend sensitively on both the life time of the massive neutron star and the polar angle. Matter in excess of up to 9 × 10−3 M⊙ becomes unbound until ~200 ms. Due to electron fractions of Ye ≈ 0.2–0.4, mainly nuclei with mass numbers A < 130 are synthesized, complementing the yields from the earlier dynamic ejecta. Mixing scenarios with these two types of ejecta can explain the abundance pattern in r-process enriched metal-poor stars. Additionally, we calculate heating rates for the decay of the freshly produced radioactive isotopes. The resulting light curve peaks in the blue band after about 4 hr. Furthermore, high opacities due to heavy r-process nuclei in the dynamic ejecta lead to a second peak in the infrared after 3–4 days.

Production of amino acids from bovine serum albumin by continuous sub-critical water hydrolysis

Abstract: The aim of this work was the determination of the best experimental conditions for the production of amino acids from bovine serum albumin (BSA) by continuous sub-critical water hydrolysis. The results were compared with conventional acid hydrolysis in HCl. At a residence time of 30 s and a pressure of 25 MPa, the highest amount of amino acids was obtained at 583 K. An increase in residence time to 90 s led to a shift of the temperature optimum to 543 K. The highest amino acid yield in sub-critical water was obtained at 563 K and 65 s. No significant influence of operating pressure (15–27 MPa) could be observed at the tested temperature (523 K) and residence time (30 s). The addition of carbon dioxide led to an increase in amino acid yield due to the acceleration of acid hydrolyzed catalysis steps. This protein treatment may provide a practical and economical solution for the disposal of protein-rich sources like marine wastes, hairs, and feathers, which are considered as waste so far.

Modeling Rotating and Swirling Turbulent Flows: A Perpetual Challenge

Abstract: Severaltypesofrotatingandswirlinge owsfora rangeofReynoldsnumbersandrotationratesorswirlintensities have been studied computationally, aimed at identifying specie c features that require special consideration in turbulence modeling. The e ows considered include turbulent channel e ows subjected to streamwise and spanwise rotation,withstationaryandmovingboundaries;developingandfullydevelopede owsinaxiallyrotatingpipes;and swirling e owsin combustorgeometriesand long pipes.Computationsperformed with threeversionsof thesecondmoment closure and two eddy-viscosity models show that the second-moment models are superior, especially when the equations are integrated up to the wall. Such models reproduced the main e ow parameters for all e ows considered in acceptable agreement with the available experimental data and direct numerical simulations. However,challengesstillremaininpredictingaccuratelysomespecie ce owfeatures,suchascapturingthetransition from a freevortex to solid-body rotation in a long straight pipewith a weak swirl, or reproducing the normal stress components in the core region. Also, the so-called uw anomaly in fully developed e ows with streamwise rotation remains questionable. For rotating e ows, the low-Reynolds-number models yield a somewhat premature e ow relaminarization at high rotation speeds.

Piezoelectricity in cellular electret films

Abstract: Permanently charged films with a cellular or porous structure represent a new family of polymer electrets. These materials show piezoelectric properties with high piezoelectric constants. The electromechanical response equations of such films are derived for their operation as sensors and as actuators. Experimental results are also presented for cellular polypropylene (pp). In particular, measurements of the direct and inverse piezoelectric constants in the frequency range 0 to 10 kHz and of the variation of these constants across the surface of the films are discussed. These measurements, performed by direct application of stress or by the use of a profilometer, an accelerometer and an interferometer yield a frequency-independent piezoelectric d/sub 33/ constant of /spl lsim/ 220 pC/N. Assuming reasonable charge distributions and charge densities, the calculated piezoelectric constants are in good agreement with the measured values. The theoretical model shows the reciprocity of the piezoelectric constants.

The INCEpTION Platform: Machine-Assisted and Knowledge-Oriented Interactive Annotation

Abstract: We introduce INCEpTION, a new annotation platform for tasks including interactive and semantic annotation (eg, concept linking, fact linking, knowledge base population, semantic frame annotation) These tasks are very time consuming and demanding for annotators, especially when knowledge bases are used We address these issues by developing an annotation platform that incorporates machine learning capabilities which actively assist and guide annotators The platform is both generic and modular It targets a range of research domains in need of semantic annotation, such as digital humanities, bioinformatics, or linguistics INCEpTION is publicly available as open-source software