Digital ergonomics and digital work planning in university education: experiences from Germany and Austria.

The publication presents an overview of the use of digital human models (DHM) in academic education at five exemplary universities in Germany and Austria. In addition to the presentation of different human models, the integration of them into the respective lectures is discussed. The teaching concepts of the individual courses of the universities, exercise examples and scenarios are presented. Experience shows that the active and independent use of digital ergonomics tools gives students pleasure and motivates them to deal intensively with complex tasks in terms of time and content. Feedback is consistently positive over all the involved lectures and universities. As a consequence of the recent Covid-19 pandemic, universities significantly increased online and blended learning. Based on the experience with the use of digital human models, the paper derives recommendations for future developments. Practical Relevance To sustain global value chains, companies are increasingly planning trans-regionally adapted products and production processes. Tools for digital ergonomics contribute to increasing competitiveness by using prospective working methods. Companies increasingly need experts with the corresponding know-how. Firmly anchoring the topic of digital ergonomics in relevant subjects of university teaching is therefore a prerequisite for this transfer of trained graduates.

Reasons and Strategies for Privacy Features in Tracking and Tracing Systems-A Systematic Literature Review.

In the course of the digitization of production facilities, tracking and tracing of assets in the supply chain is becoming increasingly relevant for the manufacturing industry. The collection and use of real-time position data of logistics, tools and load carriers are already standard procedure in entire branches of the industry today. In addition to asset tracking, the technologies used also offer new possibilities for collecting and evaluating position and biometric data of employees. Thus, these technologies can be used for monitoring performance or for tracking worker behaviour, which can lead to additional burdens and stress for employees. In this context, the collection and evaluation of employee data can influence the workplace of the affected employee in the company to his or her disadvantage. The approach of Privacy by Design can help to benefit from all the advantages of these systems, while ensuring that the impact on employee privacy is kept to a minimum. Currently, there is no survey available that reviews tracking and tracing systems supporting this important and emerging field. This work provides a systematic overview from the perspective of the impact on employee privacy. Additionally, this paper identifies and evaluates the techniques used with regard to employee privacy in industrial tracking and tracing systems. This helps to reveal new privacy preserving techniques that are currently underrepresented, therefore enabling new research opportunities in the industrial community.

Predicting the tautomeric equilibrium of acetylacetone in solution. I. The right answer for the wrong reason?

This study investigates how the various components (method, basis set, and treatment of solvent effects) of a theoretical approach influence the relative energies between keto and enol forms of acetylacetone, which is an important model system to study the solvent effects on chemical equilibria from experiment and theory. The computations show that the most popular density functional theory (DFT) approaches, such as B3LYP overestimate the stability of the enol form with respect to the keto form by approximately 10 kJ mol(-1), whereas the very promising SCS-MP2 approach is underestimating it. MP2 calculations indicate that in particular the basis set size is crucial. The Dunning Huzinaga double zeta basis (D95z(d,p)) used in previous studies overestimates the stability of the keto form considerably as does the popular split-valence plus polarization (SVP) basis. Bulk properties of the solvent included by continuum approaches strongly stabilize the keto form, but they are not sufficient to reproduce the reversal in stabilities measured by low-temperature nuclear magnetic resonance experiments in freonic solvents. Enthalpic and entropic effects further stabilize the keto form, however, the reversal is only obtained if also molecular effects are taken into account. Such molecular effects seem to influence only the energy difference between the keto and the enol forms. Trends arising due to variation in the dielectric constant of the solvent result from bulk properties of the solvent, i.e., are already nicely described by continuum approaches. As such this study delivers a deep insight into the abilities of various approaches to describe solvent effects on chemical equilibria.

Tautomeric equilibria of 3-formylacetylacetone: low-temperature NMR spectroscopy and ab initio calculations.

Keto-enol tautomerization of 3-formylacetylacetone has been studied by NMR spectroscopy, ab initio, and DFT calculations in the gas phase and continuum solvation. By employing very low temperatures in a freonic solvent, tautomeric and conformational equilibria in the slow exchange regime were analyzed in detail. The beta-tricarbonyl compound always adopts a structure with an enolized keto group irrespective of an increasing dielectric constant of the solvent when lowering the temperature of the Freon mixture. This experimentally observed tautomeric distribution of 3-formylacetylacetone is correctly reproduced by continuum solvated DFT calculations.

Conformational analysis of arginine in gas phase--a strategy for scanning the potential energy surface effectively.

The determination of all possible low-lying energy conformers of flexible molecules is of fundamental interest for various applications. It necessitates a reliable conformational search that is able to detect all important minimum structures and calculates the energies on an adequate level of theory. This work presents a strategy to identify low-energy conformers using arginine as an example by means of a force-field based conformational search in combination with high-level geometry optimizations (RI-MP2/TZVPP+). The methods used for various stages in the conformational search strategy are shown and various pitfalls are discussed. We can show that electronic energies calculated on a DFT level of theory with standard exchange-correlation functionals strongly underestimate the intramolecular stabilization resulting from stacked orientations of the guanidine and carbonyl moiety of arginine due to the deficiency of DFT to describe dispersion effects. In this case by usage of electron correlation methods, low energy conformers comprising stacked arrangements that are counterintuitive become favorable.

How important is molecular rigidity for the complex stability of artificial host-guest systems? A theoretical study on self-assembly of gas-phase arginine.

Arginine forms much less stable dimers than 2-(guanidiniocarbonyl)-1H-pyrrole-5-carboxylate although the principal binding interactions are very similar. The reasons for this difference are addressed in this work by state-of-the-art ab initio computations. The investigation shows that the extraordinary high stability of the 2-(guanidiniocarbonyl)-1H-pyrrole-5-carboxylate dimer results to about 50 % from the rigidity of its monomer. Within this study monomer and dimer conformers of arginine were calculated leading to new low lying structures which have not been reported before as well as new global minima are predicted. In these structures stacking interactions with the guanidinium moiety are especially important. For the monomer we predict the energy minimum to be the canonical form with the lowest lying zwitterionic structure being only 9 kJ mol(-1) less stable. During the course of these calculations we found that DFT did not predict the structures and their relative energy correctly in comparison to perturbation theory (MP2) and some potential reasons for the failure of DFT in these cases are discussed. Vibrational frequencies of the various structures are presented and a suitable wavenumber region for an experimental determination of the global minimum of the arginine monomer is identified. The effect of molecular rigidity on the self-assembly is probed using a local minimum of the arginine monomer which does not possess any intramolecular stabilizing effects. Our results suggest that the deliberate control of the conformational flexibility is a powerful instrument to steer the complex affinity of artificial hosts.

Geometry and cooperativity effects in adenosine-carboxylic acid complexes.

NMR experiments and theoretical investigations were performed on hydrogen bonded complexes of specifically 1- and 7-15N-labeled adenine nucleosides with carboxylic acids. By employing a freonic solvent of CDClF2 and CDF3, NMR spectra were acquired at temperatures as low as 123 K, where the regime of slow hydrogen bond exchange is reached and several higher-order complexes were found to coexist in solution. Unlike acetic acid, chloroacetic acid forms Watson-Crick complexes with the proton largely displaced from oxygen to the nitrogen acceptor in an ion pairing structure. Calculated geometries and chemical shifts of the proton in the hydrogen bridge favorably agree with experimentally determined values if vibrational averaging and solvent effects are taken into account. The results indicate that binding a second acidic ligand at the adenine Hoogsteen site in a ternary complex weakens the hydrogen bond to the Watson-Crick bound carboxylic acid. However, substituting a second adenine nucleobase for a carboxylic acid in the trimolecular complex leads to cooperative binding at Watson-Crick and Hoogsteen faces of adenosine.

"Knock-out" analogues as a tool to quantify supramolecular processes: a theoretical study of molecular interactions in guanidiniocarbonyl pyrrole carboxylate dimers.

It was recently shown experimentally that 5-(guanidiniocarbonyl)-1H-pyrrole-2-carboxylate 1, a self-complementary zwitterion, dimerizes even in water with an unprecedented high association constant of K = 170 M(-1) (J. Am. Chem. Soc. 2003, 125, 452-459). To get an insight into the importance of the various noncovalent binding interactions and of their interplay (electrostatic interactions, hydrogen binding, cooperative effects), we employ density functional theory to study the stability of several "knock-out" analogues in which single hydrogen bonds within these multiple point binding motif are switched off by replacing N-H hydrogen-donor groups with either methylene groups or an oxygen ether bridge. The influence of a highly polar solvent on the dimer stabilities is also examined. These calculations reproduce the experimental data for zwitterion 1. A comparison of 1 with the arginine dimer shows that the energy contents of the monomers also significantly influence the dimer stabilities. The analysis of the various "knock-out" analogues reveals as a main conclusion that simple models either based just on hydrogen-bond counting or on the assumption that the charge interaction by itself is the main and dominant factor fail to explain the stability of such self-assembled dimers. Our computations show that the hydrogen-bond network, the electrostatic attraction, and also their mutual interactions are responsible for the high stability of zwitterion 1.