Wear-resistant ball bearings for space applications

Ball bearings for hostile environments were developed. They consist of normal ball bearing steel parts of which the rings are coated with hard, wear-resistant, chemical vapor deposited (C.V.D) TiC. Experiments in ultrahigh vacuum, using cages of various materials with self-lubricating properties, have shown that such bearings are suitable for space applications

Tracing the Sars-CoV-2 Impact: The First Month in Switzerland

This note describes the changes in travel behaviour in response to the spread of the Sars-CoV-2 epidemic in Switzerland. The existing analyses of the Google or the national Intervisa data have limits due to missing socio-demographic details about their users. We briefly describe our GPS tracking panel and its sample. The analyses focus on the changes for different income groups and for the differences in accessibility. It will be supplemented by the weekly https://ivtmobis.ethz.ch/mobis/covid19/report

Muskuläre Biomechanik in der Sprunggelenkprothetik

Zusammenfassung: Das Ziel dieser orthopädisch-biomechanischen Studie war die Evaluation der Muskelfunktion von Patienten, bei welchen infolge unilateraler, schwerer Arthrose am oberen Sprunggelenk (OSG) eine Prothese eingesetzt wurde. Bei 10Patienten wurde vor und 1Jahr nach Implantation einer OSG-Prothese eine orthopädische und biomechanische Untersuchung durchgeführt. Dabei wurden der Schmerzscore, der "American Orthopaedic Foot and Ankle Society"- (AOFAS-)Ankle-Score, der Bewegungsumfang (ROM) des Sprunggelenks und der Unterschied zwischen dem Umfang des Unterschenkels des betroffenen und des kontralateralen gesunden Beins gemessen. Die biomechanische Beurteilung bestand aus einer simultanen Messung des maximal willkürlichen, isometrischen Drehmoments bei Plantarflexion und Dorsalextension des OSG sowie aus einem Oberflächenelektromyogramm (EMG; mittlere Frequenz und Intensität) von 4 Unterschenkelmuskeln: Tibialis anterior (TA), Gastrocnemius medialis (GM), Soleus (SO) und Peroneus longus (PL). Im Vergleich zur präoperativen Evaluation verbesserten sich der Schmerzscore von 6,7 auf 0,8Punkte, der AOFAS-Ankle-Score von 35,6 auf 92,3Punkte und der ROM nach Implantation der OSG-Prothese signifikant. Die mittlere Differenz des Unterschenkelumfangs zwischen den beiden Beinen nahm von 2,2cm auf 1,4cm ab. Dies war jedoch nicht signifikant. Das mittlere Drehmoment des betroffenen Sprunggelenks bei Dorsalextension stieg von 17,0 auf 25,8Nm und bei Plantarflexion von 15,7 auf 24,6Nm signifikant an. Bei der 1-Jahres-Nachkontrolle war die mittlere EMG-Frequenz in allen atrophischen Muskeln tiefer als bei den gesunden Muskeln der kontralateralen Seite. Ein Unterschied der mittleren EMG-Intensität zur kontralateralen gesunden Seite konnte nicht verifiziert werden. Daraus kann gefolgert werden, dass Patienten mit symptomatischer OSG-Arthrose mit einer Prothese eine bessere Funktion erlangen; 1Jahr nach der Operation entspricht dies jedoch nicht dem Ausmaß derjenigen des kontralateralen gesunden Bein

The impact of COVID-19 on mobility choices in Switzerland

We study the effect of the COVID-19 pandemic and the associated government measures on individual mobility choices in Switzerland. Our data is based on over 1,000 people for which we observe all trips during eight weeks before the pandemic and again for up to 6 months after its onset. We find an overall reduction of travel distances by 60 percent, followed by a gradual recovery during the subsequent reopening of the economy. Whereas driving distances have almost completely recovered, public transport remains under-used. The introduction of a requirement to wear a mask in public transport had no measurable impact on ridership. We study the heterogeneity of the individual travel response to the pandemic and find that it varies along socio-economic dimensions such as education and household size, with mobility tool ownership, and with personal values and lifestyles

N-(2,6-Diisopropyl­phen­yl)formamide toluene 0.33-solvate

The crystal packing of the title compound, C13H19NO·0.33C7H8, shows a channel at [001], which contains grossly disordered toluene solvent mol­ecules. The angle between the benzene ring and the mean plane of the formamide group is 71.1 (1)°. The amide groups of neighbouring mol­ecules are connected by N—H⋯O hydrogen bonds, forming 21 helical chains propagating along [001]. Mol­ecules are also connected by weak inter­molecular C—H⋯O hydrogen bonds, forming 61 helices

Pigovian Transport Pricing in Practice

Pigovian transport pricing was implemented in a large-scale field experiment in urban areas of Switzerland. The pricing varied across time, space and mode of transport. One third of the participants were given a financial incentive to reduce their external costs of transport, whereas others were provided information only or served as a control group. The pricing treatment caused a significant reduction in the external costs of transport. This reduction is a consequence of mode substitution and a shift of departure times. The effect of providing information in the absence of pricing was statistically significant only for subgroups of the sample

Scaling laws for the 2d 8-state Potts model with Fixed Boundary Conditions

We study the effects of frozen boundaries in a Monte Carlo simulation near a first order phase transition. Recent theoretical analysis of the dynamics of first order phase transitions has enabled to state the scaling laws governing the critical regime of the transition. We check these new scaling laws performing a Monte Carlo simulation of the 2d, 8-state spin Potts model. In particular, our results support a pseudo-critical beta finite-size scaling of the form beta(infinity) + a/L + b/L^2, instead of beta(infinity) + c/L^d + d/L^{2d}. Moreover, our value for the latent heat is 0.294(11), which does not coincide with the latent heat analytically derived for the same model if periodic boundary conditions are assumed, which is 0.486358...Comment: 10 pages, 3 postscript figure

Biodiversity of Andean grains: balancing market potential and sustainable livelihoods

The publication aims at shedding light on the use, nutritional properties, market potential and contribution to local livelihoods of Andean grains (quinoa, cañahua and amaranth). It addresses some of the research gaps regarding knowledge of the use, as well as the market and non-market value of these crops and their associated traditional knowledge, taking into account local livelihood assets of people living in difficult environments. It also investigates what effects the change from subsistence to market production has on farming communities and their environment. It is hoped that this book, which focuses in particular on quinoa in Southern Bolivia, will be helpful in providing food for thought in the occasion of the UN 2013 International Year of Quinoa, and serve at the same time as guidance for the future promotion of other currently underutilized crops

Structure and properties of small sodium clusters

We have investigated structure and properties of small metal clusters using all-electron ab initio theoretical methods based on the Hartree-Fock approximation and density functional theory, perturbation theory and compared results of our calculations with the available experimental data and the results of other theoretical works. We have systematically calculated the optimized geometries of neutral and singly charged sodium clusters having up to 20 atoms, their multipole moments (dipole and quadrupole), static polarizabilities, binding energies per atom, ionization potentials and frequencies of normal vibration modes. Our calculations demonstrate the great role of many-electron correlations in the formation of electronic and ionic structure of small metal clusters and form a good basis for further detailed study of their dynamic properties, as well as structure and properties of other atomic cluster systems.Comment: 47 pages, 16 figure