A new precision measurement of the {\alpha}-decay half-life of 190Pt

A laboratory measurement of the $\alpha$-decay half-life of $^{190}$Pt has been performed using a low background Frisch grid ionisation chamber. A total amount of 216.60(17) mg of natural platinum has been measured for 75.9 days. The resulting half-life is $(4.97\pm0.16)\times 10^{11}$ years, with a total uncertainty of 3.2%. This number is in good agreement with the half-life obtained using the geological comparison method

Detailed investigation of granulation processes using a fibre-optical probe and discrete element simulations

Spout fluidized beds are frequently used for the production of granules or particles through granulation, which are widely applied for example in the production of detergents, pharmaceuticals, food and fertilizers. Spout fluidized beds have a number of advantageous properties, such as high mobility of the particles preventing undesired agglomeration and enabling excellent heat transfer control. The particle growth mechanism in a spout fluidized bed as function of the particle-droplet interaction has a profound influence on the particle morphology and thus on the product quality. Nevertheless, little is known about the details of the granulation process. This is mainly due to the fact that it is not visually accessible. In this work we use fundamental, deterministic models to enable the detailed investigation of granulation behavior in a spout fluidized bed

Precise predictions for V + 2 jet backgrounds in searches for invisible Higgs decays

We present next-to-leading order QCD and electroweak (EW) theory predictions for V + 2 jet production, with V = Z, W$^{±}$, considering both the QCD and EW production modes and their interference. We focus on phase-space regions where V + 2 jet production is dominated by vector-boson fusion, and where these processes yield the dominant irreducible backgrounds in searches for invisible Higgs boson decays. Predictions at parton level are provided together with detailed prescriptions for their implementation in experimental analyses based on the reweighting of Monte Carlo samples. The key idea is that, exploiting accurate data for W + 2 jet production in combination with a theory-driven extrapolation to the Z + 2 jet process can lead to a determination of the irreducible background at the few-percent level. Particular attention is devoted to the estimate of the residual theoretical uncertainties due to unknown higher-order QCD and EW effects and their correlation between the different V + 2 jet processes, which is key to improve the sensitivity to invisible Higgs decays

Innovative drive concept for machining robots

In this paper an innovative drive concept for robots to improve their machining capability is presented. As a test bed a two-axis robot is designed and equipped with torque motors with load-sided high resolution encoders in addition to conventional gear motors with harmonic drive gearboxes. The gear motors are used for positioning tasks while the torque motors in particular compensate static and dynamic load-sided angle errors. The model-based control algorithm is decoupled and separately actuates both the servo gear and torque motors. It is shown that a considerable increase of performance is possible when adding the torque motors especially regarding the compensation of dynamic angle errors. The paper will present the design and details of the new drive concept, the modeling basics and first simulation results

Discrete element modeling and fibre optical measurements for fluidized bed spray granulation

Spout fluidized beds are frequently used for the production of granules or\ud particles through granulation. The products find application in a large variety of\ud applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized\ud beds have a number of advantageous properties, such as a high mobility of the particles,\ud which prevents undesired agglomeration and yields excellent heat transfer properties. The\ud particle growth mechanism in a spout fluidized bed as function of particle-droplet\ud interaction has a profound influence on the particle morphology and thus on the product\ud quality. Nevertheless, little is known about the details of the granulation process. This is\ud mainly due to the fact that the granulation process is not visually accessible. In this work\ud we use fundamental, deterministic models to enable the detailed investigation of\ud granulation behaviour in a spout fluidized bed. A discrete element model is used\ud describing the dynamics of the continuous gas-phase and the discrete droplets and\ud particles. For each element momentum balances are solved. The momentum transfer\ud among each of the three phases is described in detail at the level of individual elements.\ud The results from the discrete element model simulations are compared with local\ud measurements of particle volume fractions as well as particle velocities by using a novel\ud fibre optical probe in a fluidized bed of 400 mm I.D. Simulations and experiments were\ud carried out for two different cases using Geldart B type aluminium oxide particles: a\ud freely bubbling fluidized bed and a spout fluidized bed with the presence of droplets. It is\ud demonstrated how the discrete element model can be used to obtain information about the\ud interaction of the discrete phases, i.e. the growth zone in a spout fluidized bed. Eventually\ud this kind of information can be used to obtain closure information required in more coarse\ud grained model

Hard rod gas with long-range interactions: Exact predictions for hydrodynamic properties of continuum systems from discrete models

One-dimensional hard rod gases are explicitly constructed as the limits of discrete systems: exclusion processes involving particles of arbitrary length. Those continuum many-body systems in general do not exhibit the same hydrodynamic properties as the underlying discrete models. Considering as examples a hard rod gas with additional long-range interaction and the generalized asymmetric exclusion process for extended particles ($\ell$-ASEP), it is shown how a correspondence between continuous and discrete systems must be established instead. This opens up a new possibility to exactly predict the hydrodynamic behaviour of this continuum system under Eulerian scaling by solving its discrete counterpart with analytical or numerical tools. As an illustration, simulations of the totally asymmetric exclusion process ($\ell$-TASEP) are compared to analytical solutions of the model and applied to the corresponding hard rod gas. The case of short-range interaction is treated separately.Comment: 19 pages, 8 figure

NLO QCD+EW predictions for 2ℓ\ell2v diboson signatures at the LHC

We present next-to-leading order (NLO) calculations including QCD and electroweak (EW) corrections for 2$\ell$2ν diboson signatures with two opposite-charge leptons and two neutrinos. Specifically, we study the processes $pp \to e^+\mu^-\nu_e\overline{\nu}_{\mu}$ and $pp \to e^+e^-\nu\overline{\nu}$, including all relevant off-shell diboson channels, $W^+W^-, ZZ, \gamma Z$, as well as non-resonant contributions. Photon-induced processes are computed at NLO EW, and we discuss subtle differences related to the definition and the renormalisation of the coupling α for processes with initial- and final-state photons. All calculations are performed within the automated Munich/Sherpa+OpenLoops frameworks, and we provide numerical predictions for the LHC at 13 TeV. The behaviour of the corrections is investigated with emphasis on the high-energy regime, where NLO EW effects can amount to tens of percent due to large Sudakov logarithms. The interplay between $W$ $W$and $ZZ$ contributions to the same-flavour channel, $pp \to e^+e^-\nu\overline{\nu}$, is discussed in detail, and a quantitative analysis of photon-induced contributions is presented. Finally, we consider approximations that account for all sources of large logarithms, at high and low energy, by combining virtual EW corrections with a YFS soft-photon resummation or a QED parton shower

Comparison of fibre optical measurements and discrete element simulations for the study of granulation in a spout fluidized bed

Spout fluidized beds are frequently used for the production of granules or particles through granulation. The products find application in a large variety of applications, for example detergents, fertilizers, pharmaceuticals and food. Spout fluidized beds have a number of advantageous properties, such as a high mobility of the particles, which prevents undesired agglomeration and yields excellent heat transfer properties. The particle growth mechanism in a spout fluidized bed as function of particle-droplet interaction has a profound influence on the particle morphology and thus on the product quality. Nevertheless, little is known about the details of the granulation process. This is mainly due to the fact that the granulation process is not visually accessible. In this work we use fundamental, deterministic models to enable the detailed investigation of granulation behaviour in a spout fluidized bed. A discrete element model is used describing the dynamics of the continuous gas-phase and the discrete droplets and particles. For each element momentum balances are solved. The momentum transfer among each of the three phases is described in detail at the level of individual elements. The results from the discrete element model simulations are compared with local measurements of particle volume fractions as well as particle velocities by using a novel fibre optical probe in a fluidized bed of 400 mm I.D. Simulations and experiments were carried out for three different cases using Geldart B type aluminium oxide particles: a freely bubbling fluidized bed; a spout fluidized bed without the presence of droplets and a spout fluidized bed with the presence of droplets. It is demonstrated how the discrete element model can be used to obtain information about the interaction of the discrete phases, i.e. the growth zone in a spout fluidized bed. Eventually this kind of information can be used to obtain closure information required in more coarse grained models

Simulation of cyclotron resonant scattering features: The effect of bulk velocity

X-ray binary systems consisting of a mass donating optical star and a highly magnetized neutron star, under the right circumstances, show quantum mechanical absorption features in the observed spectra called cyclotron resonant scattering features (CRSFs). We have developed a simulation to model CRSFs using Monte Carlo methods. We calculate Green's tables which can be used to imprint CRSFs to arbitrary X-ray continua. Our simulation keeps track of scattering parameters of individual photons, extends the number of variable parameters of previous works, and allows for more flexible geometries. Here we focus on the influence of bulk velocity of the accreted matter on the CRSF line shapes and positions