Evaluation of pressure insoles during running

Pressure insoles could be a useful tool for measuring vertical ground reaction forces during field tests. However, several studies have indicated problems that can affect the reliability of the output of the insoles. The aim of this study was to test the reliability, durability and repeatability of Tekscan F-scan pressure insoles with 2 running tests in combination with walks across and jumps on a force platform. During the both running tests in this paper the sensitivity of the pressure insoles deteriorated rapidly. A comparison of the force output of the pressure insoles and force platform during walks and jumps showed clear differences in both the shape and magnitude of the force curves. The rapid decrease in sensitivity and frequent need of calibration of the pressure insoles make the pressure insoles not reliable and practical enough for measuring vertical ground reaction forces during running

Predicting microalgae growth

Paid Open Acces

Jet-engine vibration model for the estimation of pylon-wing interface loads

A vibroacoustic experiment is planned to be performed on a stand-alone wing of an Airbus A320. During the experiment the operational vibrations of the wing, usually induced by engine vibration loads, will be replicated to investigate the transmission of vibrations throughout the wing. As there is no engine available to introduce these vibrational loads, a previously developed multiaxial shaker system, able to reproduce engine loads in the pylon-wing interface along and about multiple axes simultaneously, will be utilized for structural excitation. However, there are no measured spectra of loads in pylon-wing interfaces available and respective measurements which could identify these loads are currently not realizable.As a consequence, an attempt is made to develop an jet engine vibration model from minimal input data that allows the estimation of interface loads. The approach combines the estimation of worst-case bearing forces in the engine by using design phase data, in-flight data to identify engine properties related to specific flight-conditions, a simple substitute model of an engine and further data from unrelated projects. The future goal of this project is to update a FEM model of the wing to investigate the impact of varying engine locations along it on the resulting cabin noise

Nonspherical Nanoparticle Shape Stability Is Affected by Complex Manufacturing Aspects: Its Implications for Drug Delivery and Targeting

The shape of nanoparticles is known recently as an important design parameter influencing considerably the fate of nanoparticles with and in biological systems. Several manufacturing techniques to generate nonspherical nanoparticles as well as studies on in vitro and in vivo effects thereof have been described. However, nonspherical nanoparticle shape stability in physiological-related conditions and the impact of formulation parameters on nonspherical nanoparticle resistance still need to be investigated. To address these issues, different nanoparticle fabrication methods using biodegradable polymers are explored to produce nonspherical nanoparticles via the prevailing film-stretching method. In addition, systematic comparisons to other nanoparticle systems prepared by different manufacturing techniques and less biodegradable materials (but still commonly utilized for drug delivery and targeting) are conducted. The study evinces that the strong interplay from multiple nanoparticle properties (i.e., internal structure, Young's modulus, surface roughness, liquefaction temperature [glass transition (Tg) or melting (Tm)], porosity, and surface hydrophobicity) is present. It is not possible to predict the nonsphericity longevity by merely one or two factor(s). The most influential features in preserving the nonsphericity of nanoparticles are existence of internal structure and low surface hydrophobicity (i.e., surface-free energy (SFE) > ≈55 mN m−1, material–water interfacial tension 10 nm), porous (>1 m2 g−1), and in possession of low bulk liquefaction temperature (<100 °C). Interestingly, low surface hydrophobicity of nanoparticles can be obtained indirectly by the significant presence of residual stabilizers. Therefore, it is strongly suggested that nonsphericity of particle systems is highly dependent on surface chemistry but cannot be appraised separately from other factors. These results and reviews allot valuable guidelines for the design and manufacturing of nonspherical nanoparticles having adequate shape stability, thereby appropriate with their usage purposes. Furthermore, they can assist in understanding and explaining the possible mechanisms of nonspherical nanoparticles effectivity loss and distinctive material behavior at the nanoscale. © 2019 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

The effect of migration on unionization in Austria

We analyze how native employees’ union membership rates change in response to foreign employees using Austrian administrative data for the period 2002 to 2012. Using an instrumental variables approach, our results indicate a negative effect of immigrant employees on native employees’ unionization rates at the firm level. The negative effect is the result of a greater—mostly voluntary—turnover of unionized native employees in firms with a larger share of migrants, but it is not caused by native employees leaving unions or firms’ reduced hiring of native union members

High-resolution vibroacoustic measurement and analysis of the DLR ISTAR aircraft to assess engine-induced cabin noise

Aircraft engines, especially when mounted directly to the fuselage, inject a considerable amount of tonal vibrations into the airframe causing audible and comfort reducing cabin noise. Reducing this noise requires the development of specialised noise reduction systems. This is a time consuming and expensive endeavour. To speed up and ease this process a sufficiently detailed numerical model of the aircraft structure and the force injected by the engines is required. The DLR ISTAR, a Dassault Falcon 2000LX, was used for an extensive vibration measurement campaign. The goal of this campaign was twofold: Getting spatially dense information about the aircrafts vibro-acoustic behaviour to later update a finite element model for calculations in the mid-frequency range and to analyse the vibration injected by running engines into the fuselage structure. The measurements include the vibration response to both shaker excitation and engine vibration of the DLR ISTAR at about 1300 positions acquired by a rowing grid of sensors. The results are presented in the form of operational deflection shapes and first calculations of energy transfer paths using structural intensity analysi

Case Report: Hypertrophic cardiomyopathy with recurrent episodes of ventricular fibrillation and concurrent sinus arrest

BackgroundHypertrophic cardiomyopathy (HCM) is a serious hereditary cardiomyopathy. It is characterized morphologically by an increased left ventricular wall thickness and mass and functionally by enhanced global chamber function and myocellular contractility, diastolic dysfunction, and myocardial fibrosis development. Typically, patients with HCM experience atrial fibrillation (AF), syncope, and ventricular fibrillation (VF), causing severe symptoms and cardiac arrest. In contrast, sinoatrial node (SAN) arrest in the setting of HCM is uncommon. In particular, during VF, it has not been described so far.Case summaryIn this study, we report an 18-year-old woman patient with sudden cardiac arrest due to VF and successful cardiopulmonary resuscitation as the first clinical manifestation of non-obstructive HCM. Subsequently, a subcutaneous implantable cardioverter-defibrillator (ICD) was implanted for secondary VF prophylaxis. However, additional episodes of VF occurred. During these, device interrogation revealed a combined occurrence of VF, bradycardia, and SAN arrest, requiring a device exchange into a dual-chamber ICD. A heterozygous, pathogenic variant of the MYH7 gene (c.2155C&gt;T; p.Arg719Trp) was identified as causative for HCM.DiscussionFirst published in 1994, the particular MYH7 variant (p.Arg719Trp) was described in HCM patients with a high incidence of premature cardiac death and a reduced life expectancy. Electrophysiological studies on HCM patients are mainly performed to treat AF and ventricular tachycardia. Further extraordinary arrhythmic phenotypes were reported only in a few HCM patients. Taken together, the present case with documented co-existing VF and SAN arrest is rare and also emphasizes addressing the presence of SAN arrest (in particular, during VF episodes) in HCM patients when a distinct ICD device is considered for implantation

Numerical investigation of power flow input into a fuselage due to jet engine induced wing vibrations

The wings of passenger aircrafts are constantly vibrating due to various loads. There are transient low-frequency vibrations caused by gust loads. But there are also higher-frequency vibrations caused by the vibration load of the jet engines. The higher-frequency stationary vibrations of the wing are partially introduced as a power flow into the fuselage and radiated there as sound, which is then perceived as noise. In this work, which is part of the EU CleanSky2 framework, this chain of effects is being investigated in more detail aiming for the quantification of the vibrational power flow input into the fuselage by utilizing structural intensity. In this paper, numerical investigations are carried out on FEM models of an Airbus A320 wing generated with a parametric model generator. First, the structural components mainly responsible for the power transmission are identified, and second, the magnitude of the power input into the fuselage is determined in dependence of the pylon position along the wing. The engine vibrations are approximated by a custom-developed model. In the further course of the project, these numerical results will be validated by a test campaign. For this purpose, a real wing of an A320 is available as a test structur