Numerical verification of the continuous calculation method for tip stress during the driving process of the dynamic penetration test

This paper presents a calculation method for obtaining the continuous variation in stress between the tip and the soil during dynamic penetration tests, particularly in the case of using the Panda 3® penetration testing device. The originality of the method is that the tip stress can be computed continuously throughout the driving process. For each impact of the hammer on the penetrometer, data are recorded by sensors located at the top of the apparatus. Then, the stress at the tip and the displacement of the apparatus are calculated with a method based on the propagation of waves in the device. A three-dimensional numerical model of the penetration test, based on the Panda 3® specifications and using the discrete element method (DEM), is proposed in this paper. The purpose of the simulations is to validate the calculation method by comparing the curves of the tip stress versus the penetration distance obtained in two different ways, the first being the distance directly observed at the tip and the second being the distance calculated from the data recorded at the top of the penetrometer, as with the experimental device. The entire apparatus is represented, including the hammer, the rod, and the tip, and is driven into the model soil. The calculation method is applied, and the results are compared to the actual response of the soil to the driving of the penetrometer directly at the tip, which can be obtained with the numerical model. The responses are found to be very similar, confirming the theoretical framework and its underlying assumptions. This method is applied to dynamic penetration tests and provides the opportunity to obtain mechanical parameters other than the tip resistance from the tests.     

Ram‐air kite airfoil and reinforcements optimization for airborne wind energy applications

We present a multidisciplinary design optimization method for the profile and structural reinforcement layout of a ram‐air kite rib. The aim is to minimize the structural elastic energy and to maximize the traction power of a ram‐air kite used for airborne wind energy generation. Because of the large deformations occurring during flight, a fluid‐structure interaction (FSI) routine is included in the optimization, which determines the actual deformed rib geometry and its corresponding aerodynamic characteristics. A qualitative comparison between FSI inclusion and exclusion in the optimization is given. Discrepancies in airfoil profile and structural layout are observed.     

The ETH‐MAV Team in the MBZ International Robotics Challenge

This study describes the hardware and software systems of the Micro Aerial Vehicle (MAV) platforms used by the ETH Zurich team in the 2017 Mohamed Bin Zayed International Robotics Challenge (MBZIRC). The aim was to develop robust outdoor platforms with the autonomous capabilities required for the competition, by applying and integrating knowledge from various fields, including computer vision, sensor fusion, optimal control, and probabilistic robotics. This paper presents the major components and structures of the system architectures and reports on experimental findings for the MAV‐based challenges in the competition. Main highlights include securing the second place both in the individual search, pick, and place the task of Challenge 3 and the Grand Challenge, with autonomous landing executed in less than 1 min and a visual servoing success rate of over for object pickups.     

Identification and Optimization of the First Highly Selective GLUT1 Inhibitor BAY‐876

Despite the long‐known fact that the facilitative glucose transporter GLUT1 is one of the key players safeguarding the increase in glucose consumption of many tumor entities even under conditions of normal oxygen supply (known as the Warburg effect), only few endeavors have been undertaken to find a GLUT1‐selective small‐molecule inhibitor. Because other transporters of the GLUT1 family are involved in crucial processes, these transporters should not be addressed by such an inhibitor. A high‐throughput screen against a library of ～3 million compounds was performed to find a small molecule with this challenging potency and selectivity profile. The N‐(1H‐pyrazol‐4‐yl)quinoline‐4‐carboxamides were identified as an excellent starting point for further compound optimization. After extensive structure–activity relationship explorations, single‐digit nanomolar inhibitors with a selectivity factor of >100 against GLUT2, GLUT3, and GLUT4 were obtained. The most promising compound, BAY‐876 [N⁴‐[1‐(4‐cyanobenzyl)‐5‐methyl‐3‐(trifluoromethyl)‐1H‐pyrazol‐4‐yl]‐7‐fluoroquinoline‐2,4‐dicarboxamide], showed good metabolic stability in vitro and high oral bioavailability in vivo.     

Anaerobic methane oxidation and aerobic methane production in an east African great lake (Lake Kivu)

We investigated CH₄ oxidation in the water column of Lake Kivu, a deep meromictic tropical lake with CH₄-rich anoxic deep waters. Depth profiles of dissolved gases (CH₄ and N₂O) and a diversity of potential electron acceptors for anaerobic CH₄ oxidation (NO₃^?, SO₄^2?, Fe and Mn oxides) were determined during six field campaigns between June 2011 and August 2014. Denitrification measurements based on stable isotope labelling experiments were performed twice. In addition, we quantified aerobic and anaerobic CH₄ oxidation, NO₃^? and SO₄^2? consumption rates, with and without the presence of an inhibitor of SO₄^2?-reducing bacteria activity. Aerobic CH₄ production was also measured in parallel incubations with the addition of an inhibitor of aerobic CH₄ oxidation. The maximum aerobic and anaerobic CH₄ oxidation rates were estimated to be 27?±?2 and 16?±?8?μmol/L/d, respectively. We observed a difference in the relative importance of aerobic and anaerobic CH₄ oxidation during the rainy and the dry season, with a greater role for aerobic oxidation during the dry season. Lower anaerobic CH₄ oxidation rates were measured in presence of molybdate in half of the measurements, suggesting the occurrence of linkage between SO₄^2? reduction and anaerobic CH₄ oxidation. NO₃^? consumption and dissolved Mn production rates were never high enough to sustain the measured anaerobic CH₄ oxidation, reinforcing the idea of a coupling between SO₄^2? reduction and CH₄ oxidation in the anoxic waters of Lake Kivu. Finally, significant rates (up to 0.37?μmol/L/d) of pelagic CH₄ production were also measured in oxygenated waters.     

Effect of solvent type on preparation of ethyl cellulose microparticles by solvent evaporation method with double emulsion system using focused beam reflectance measurement

The purpose of this study was to investigate the effect of solvent type on the solidification rate of ethyl cellulose (EC) microparticles and particle size/distribution of emulsion droplets/hardened microparticles during the solvent evaporation process using focused beam reflectance measurement (FBRM). EC microparticles were prepared with a water‐in‐oil‐in‐water solvent evaporation method using various solvents, including dichloromethane, dichloromethane–methanol (1:1), ethyl acetate and chloroform. The particle size/distribution of the emulsion droplets/hardened microparticles was monitored using FBRM. The morphology of EC microparticles was characterized using scanning electron microscopy (SEM). The transformation of the emulsion droplets into solid microparticles for all solvents occurred within the first 10–90 min. The square weighted mean chord length of EC microparticles prepared using chloroform was smallest, but the chord count was not the highest. The chord length distribution (CLD) measured by FBRM showed that a larger mean particle size gave longer CLD and a lower peak of particle number. SEM data revealed that the morphology of microparticles was influenced by the type of solvent. FBRM can be employed for online monitoring of the shift in the microparticle CLD and detect transformation of emulsion droplets into solid microparticles during the solvent evaporation process. The microparticle CLD and transformation process were strongly influenced by solvent type. © 2017 Society of Chemical Industry