A new method to compute mechanical properties of a standing skyline for cable yarding.

Cable-based technologies are the backbone for logistics of timber or construction material on impassable terrain. In Central Europe, the use of standing skylines with pre-stressed, both-sided fixed-anchor cables and multi-span configurations with internal intermediate supports is common. To ensure a safe and cost-effective set-up for cable road operations, it is essential to identify and compute the properties of the skyline (e.g. load path, tensile forces). This task is challenging because it requires dealing with the non-linear behaviour of the cable structure under the load and has to include all significant physical effects. Several approaches have previously been proposed as practical solutions, however not all physical effects were covered by those approaches, such as the inclination-dependent elastic prolongation of the cable or the longitudinal deflection of the sagging carriage. With our new proposed approach, we aim to close this gap of knowledge, and consider all relevant physical effects. We present a non-linear approach that is able to compute the properties of a wide range of standing skyline configurations, including those with additional cables. This approach offers an extensive solution and a flexible framework for considering individual configurations or particularities by adding equations to the equation system.

Bragg Diffraction of Large Organic Molecules.

We demonstrate Bragg diffraction of the antibiotic ciprofloxacin and the dye molecule phthalocyanine at a thick optical grating. The observed patterns show a single dominant diffraction order with the expected dependence on the incidence angle as well as oscillating population transfer between the undiffracted and diffracted beams. We achieve an equal-amplitude splitting of 14ℏk (photon momenta) and maximum momentum transfer of 18ℏk. This paves the way for efficient, large-momentum beam splitters and mirrors for hot and complex molecules.

Conformer Selection by Matter-Wave Interference.

We establish that matter-wave diffraction at near-resonant ultraviolet optical gratings can be used to spatially separate individual conformers of complex molecules. Our calculations show that the conformational purity of the prepared beam can be close to 100% and that all molecules remain in their electronic ground state. The proposed technique is independent of the dipole moment and the spin of the molecule and thus paves the way for structure-sensitive experiments with hydrocarbons and biomolecules, such as neurotransmitters and hormones, which have evaded conformer-pure isolation so far.

OptoBase: A Web Platform for Molecular Optogenetics.

OptoBase is an online platform for molecular optogenetics. At its core is a hand-annotated and ontology-supported database that aims to cover all existing optogenetic switches and publications, which is further complemented with a collection of convenient optogenetics-related web tools. OptoBase is meant both for expert optogeneticists to easily keep track of the field, as well as for all researchers who find optogenetics inviting as a powerful tool to address their biological questions of interest. It is available at https://www.optobase.org . This work also presents OptoBase-based analysis of the trends in molecular optogenetics.

In search of multipath interference using large molecules.

The superposition principle is fundamental to the quantum description of both light and matter. Recently, a number of experiments have sought to directly test this principle using coherent light, single photons, and nuclear spin states. We extend these experiments to massive particles for the first time. We compare the interference patterns arising from a beam of large dye molecules diffracting at single, double, and triple slit material masks to place limits on any high-order, or multipath, contributions. We observe an upper bound of less than one particle in a hundred deviating from the expectations of quantum mechanics over a broad range of transverse momenta and de Broglie wavelength.

An atomically thin matter-wave beamsplitter.

Matter-wave interferometry has become an essential tool in studies on the foundations of quantum physics and for precision measurements. Mechanical gratings have played an important role as coherent beamsplitters for atoms, molecules and clusters, because the basic diffraction mechanism is the same for all particles. However, polarizable objects may experience van der Waals shifts when they pass the grating walls, and the undesired dephasing may prevent interferometry with massive objects. Here, we explore how to minimize this perturbation by reducing the thickness of the diffraction mask to its ultimate physical limit, that is, the thickness of a single atom. We have fabricated diffraction masks in single-layer and bilayer graphene as well as in a 1 nm thin carbonaceous biphenyl membrane. We identify conditions to transform an array of single-layer graphene nanoribbons into a grating of carbon nanoscrolls. We show that all these ultrathin nanomasks can be used for high-contrast quantum diffraction of massive molecules. They can be seen as a nanomechanical answer to the question debated by Bohr and Einstein of whether a softly suspended double slit would destroy quantum interference. In agreement with Bohr's reasoning we show that quantum coherence prevails, even in the limit of atomically thin gratings.