Spectroscopic database for TROPOMI/Sentinel-5P: CO and H2O at 2.3μm

The TROPOspheric Monitoring Instrument (TROPOMI) aboard the European Space Agency's Copernicus Sentinel-5 Precursor satellite, to be launched this year, mandates high-accuracy spectral reference data for CO and H2O in the 2.3μm region [1]. We present measurements of absorption line parameters for H2O and for the 2-0 rovibrational band of CO to be used in TROPOMI atmospheric retrievals. The experiments were carried out on a Bruker IFS 125HR Fourier transform spectrometer and a multispectrum fitting software developed at DLR was used for parameter retrieval [2] using the Hartmann-Tran-Profile [3,4]. In the case of carbon monoxide, we report line intensities, air-broadening and -shift parameters for lines of the 2-0 rovibrational band, which serve as a useful validation of the HITRAN2012 spectral database [5] while our analysis of Dicke narrowing, speed dependence and Rosenkranz line mixing emphasizes the importance of modern line shape functions. Comparisons with previous studies of these non-Voigt parameters (e.g. [6]) show good agreement. As for H2O, spectral parameters were measured in the 4190cm-1-4340cm-1 spectral range. Comparisons of measured line intensities of the ν3 band show remarkable agreement (<1.5% deviation on average) with ab initio values [7,8] and we will present air-broadening, -narrowing and -shift parameters together with their temperature dependences. References [1] J.P. Veefkind et al, Remote Sensing of Environment 120, 70 (2012) [2] J. Loos et al, 13th HITRAN database conference, 2014 (doi: 10.5281/zenodo.11156) [3] N.H. Ngo et al, JQSRT 129, 89 (2013) [4] N.H. Ngo et al, JQSRT 134, 105 (2014) [5] L.S. Rothman et al, JQSRT 130, 4 (2013) [6] V.M. Devi et al, JQSRT 113, 1013 (2012) [7] L. Lodi et al, J Chem Phys 135, 034113 (2011) [8] J. Tennyson, University College London, Private communicatio

Model-Based Deadtime Compensation of Virtual Machine Startup Times

Scaling the amount of resources allocated to an application according to the actual load is a challenging problem in cloud computing. The emergence of autoscaling techniques allows for autonomous decisions to be taken when to acquire or release resources. The actuation of these decisions is however affected by time delays. Therefore, it becomes critical for the autoscaler to account for this phenomenon, in order to avoid over- or under-provisioning. This paper presents a delay-compensator inspired by the Smith predictor. The compensator allows one to close a simple feedback loop around a cloud application with a large, time-varying delay, preserving the stability of the controlled system. It also makes it possible for the closed-loop system to converge to a steady-state, even in presence of resource quantization. The presented approach is compared to a threshold-based controller with a cooldown period, that is typically adopted in industrial applications

In Situ RheoNMR Correlation of Polymer Segmental Mobility with Mechanical Properties during Hydrogel Synthesis

Understanding polymer gelation over multiple length-scales is crucial to develop advanced materials. An experimental setup is developed that combines rheological measurements with simultaneous time-domain $^{1}$H NMR relaxometry (TD-NMR) techniques, which are used to study molecular motion (<10 nm) in soft matter. This so-called low-field RheoNMR setup is used to study the impact of varying degrees of crosslinking (DC) on the gelation kinetics of acrylic acid (AAc) and N,N′-methylene bisacrylamide (MBA) free radical crosslinking copolymerization. A stretched exponential function describes the T$_{2}$ relaxation curves throughout the gelation process. The stretching exponent β decreases from 0.90 to 0.67 as a function of increasing DC, suggesting an increase in network heterogeneity with a broad T$_{2}$ distribution at higher DC. The inverse correlation of the elastic modulus G′ with T2 relaxation times reveals a pronounced molecular rigidity for higher DC at early gelation times, indicating the formation of inelastic, rigid domains such as crosslinking clusters. The authors further correlate G′ with the polymer concentration during gelation using a T$_{1}$ filter for solvent suppression. A characteristic scaling exponent of 2.3 is found, which is in agreement with theoretical predictions of G′ based on the confining tube model in semi-dilute entangled polymer solutions

Teaching agile hardware development with an open‐source engineering simulator: An evaluation with industry participants

Educational games are increasingly used to teach Agile development approaches to practitioners. Most of these training modules simplify the development environment, for example, by using LEGO bricks or playing cards. This oversimplification has been shown to result in limited transferability of learning to industrial practice. Furthermore, there is a lack of teaching modules that specifically address the challenges of applying Agile to physical products. In this paper, we present an open-source educational game that realistically simulates a hardware development project to teach Agile principles. Over 2 days, participants design, manufacture, and test modifications for a physical wire bending machine within an authentic engineering and production setting. The training mimics the typical roles, processes, and tools of industrial engineering teams to reflect the challenges of Agile hardware development. The module was evaluated with 44 industry professionals regarding perceived learning and user reaction. A combination of quantitative and qualitative methods was used for the experimental evaluation. The results showed a positive learning effect as the participants\u27 average agreement with Agile principles increased through the training. Concerning user reaction, respondents reported a high degree of relevance, interaction, and confidence, indicating that the realistic simulation of the hardware development appropriately balanced the degree of realism with simplicity. The study showcases the opportunities of properly aligning game components to provoke learning situations targeted by the instructors. It contributes to the extant literature by providing a design framework (product, process, setting, and instruction) and open-source access to the tools used for implementation

Increased Resting-State Perfusion after Repeated Encoding Is Related to Later Retrieval of Declarative Associative Memories

Electrophysiological studies in animals have shown coordinated reactivation of neuronal ensembles during a restricted time period of behavioral inactivity that immediately followed active encoding. In the present study we directly investigated off-line processing of associative memory formation in the human brain. Subjects' regional cerebral blood flow (rCBF) as a surrogate marker of neural activity during rest was measured by MR-based perfusion imaging in a sample of 14 healthy male subjects prior to (Pre2) and after (Post) extensive learning of 24 face-name associations within a selective reminding task (SR). Results demonstrated significant Post-Pre2 rCBF increases in hippocampal and temporal lobe regions, while in a control comparison of two perfusion scans with no learning task in-between (Pre2-Pre1) no differences in rCBF emerged. Post perfusion scanning was followed by a surprise cued associative recall task from which two types of correctly retrieved names were obtained: older names already correctly retrieved at least once during one of the SR blocks, and recent names acquired during the last SR block immediately prior to the Post scan. In the anterior hippocampus individual perfusion increases were correlated with both correct retrievals of older and recent names. By contrast, older but not recently learned names showed a significant correlation with perfusion increases in the left lateral temporal cortex known to be associated with long-term memory. Recent, but not older names were correlated with dopaminergic midbrain structures reported to contribute to the persistence of memory traces for novel information. Although the direct investigation of off-line memory processing did not permit concomitant experimental control, neither intentional rehearsal, nor substantial variations in subjects' states of alertness appear to contribute to present results. We suggest that the observed rCBF increases might reflect processes that possibly contribute to the long-term persistence of memory traces

Unified Emergence of Energy Scales and Cosmic Inflation

In the quest for unification of the Standard Model with gravity, classical scale invariance can be utilized to dynamically generate the Planck mass $M_\mathrm{Pl}$. Then, the relation of Planck scale physics to the scale of electroweak symmetry breaking $\mu_H$ requires further explanation. In this paper, we propose a model that uses the spontaneous breaking of scale invariance in the scalar sector as a unified origin for dynamical generation of both scales. Using the Gildener-Weinberg approximation, only one scalar acquires a vacuum expectation value of $v_S \sim (10^{16-17})\,\mathrm{GeV}$, thus radiatively generating $M_\mathrm{Pl} \approx \beta_S^{1/2} v_S$ and $\mu_H$ via the neutrino option with right handed neutrino masses $m_N = y_M v_S \sim 10^7 \,\mathrm{GeV}$. Consequently, active SM neutrinos are given a mass with the inclusion of a type-I seesaw mechanism. Furthermore, we adopt an unbroken $Z_2$ symmetry and a $Z_2$-odd set of right-handed Majorana neutrinos $\chi$ that do not take part in the neutrino option and are able to produce the correct dark matter relic abundance (dominantly) via inflaton decay. The model also describes cosmic inflation and the inflationary CMB observables are predicted to interpolate between those of $R^2$ and linear chaotic inflationary model and are thus well within the strongest experimental constraints.Comment: 21+10 pages, 11 figures, 1 table, v2: matches published versio

Computational Steering in Civil Engineering

Computational Steering provides methods for the integration of modeling, simulation, visualization, data analysis and post processing. The user has full control over a running simulation and the possibility to modify objects (geometry and other properties), boundary conditions and other parameters of the system interactively. The objective of such a system is to explore the effects of changes made immediately and thus to optimize the target problem interactively. We present a computational steering based system for fluid flow problems in civil engineering. It is based on three software components as shown in figure 1. The modeler is the CAD-system AutoCAD, which offers a powerful programming interface allowing an efficient access to the geometric data. It also offers convenient manipulators for geometric objects. The simulation kernel is a Lattice-Boltzmann (LB) solver for the Navier-Stokes equations, which is especially suitable for instationary flows in complex geometries. For the visualization and postprocessing we use the software tool AVS, which provides a powerful programming interface and allows the efficient visualization of flow fields. These three components are interconnected through two communication modules and three interfaces as depicted in figure 1. Interface 1 is responsible for the transformation of the modified system for the simulation kernel, interface 2 is responsible for the proper preparation of the simulation data whereas interface 3 transforms the data from the modeler into a format suitable for the visualization system. The whole system is synchronized by the two communication modules

Internationalism as A Current in The Peace Movement: A Symposium

Internationalism as A Current in The Peace Movement: A Symposiu