Investigation of inner contact and friction conditions of a spherical roller bearing using multi-body simulation

At the Institute of Machine Elements, Gears, and Transmission (MEGT, University of Kaiserslautern) a spherical roller bearing has been modeled in an multi body system (MBS) environment. The use of the commercial MBS (multi-body system) software (MSC ADAMS) allows the development of user-written subroutines for contact recognition and the calculation of contact forces. Those subroutines can help understanding the principles of friction phenomena inside spherical roller bearings, while the measurement of those effects is difficult.Measurements on a friction torque test rig for roller bearings are used to validate the MBS models. Since the sum of all contact forces equals the friction of the bearing, this test stand provides a way for validation of the contact and friction calculations

StyleGAN-T: Unlocking the Power of GANs for Fast Large-Scale Text-to-Image Synthesis

Text-to-image synthesis has recently seen significant progress thanks to large pretrained language models, large-scale training data, and the introduction of scalable model families such as diffusion and autoregressive models. However, the best-performing models require iterative evaluation to generate a single sample. In contrast, generative adversarial networks (GANs) only need a single forward pass. They are thus much faster, but they currently remain far behind the state-of-the-art in large-scale text-to-image synthesis. This paper aims to identify the necessary steps to regain competitiveness. Our proposed model, StyleGAN-T, addresses the specific requirements of large-scale text-to-image synthesis, such as large capacity, stable training on diverse datasets, strong text alignment, and controllable variation vs. text alignment tradeoff. StyleGAN-T significantly improves over previous GANs and outperforms distilled diffusion models - the previous state-of-the-art in fast text-to-image synthesis - in terms of sample quality and speed.Comment: Project page: https://sites.google.com/view/stylegan-t

The complexity of mesoporous silica nanomaterials unravelled by single molecule microscopy

Mesoporous silica nanomaterials are a novel class of materials that offer a highly complex porous network with nanometre-sized channels into which a wide amount of differently sized guests can be incorporated. This makes them an ideal host for various applications for example in catalysis, chromatography and nanomedicine. For these applications, analyzing the host properties and understanding the complicated host–guest interactions is of pivotal importance. In this perspective we review some of our recent work that demonstrates that single molecule microscopy techniques can be utilized to characterize the porous silica host with unprecedented detail. Furthermore, the single molecule studies reveal sample heterogeneities and are a highly efficient tool to gain direct mechanistic insights into the host–guest interactions. Single molecule microscopy thus contributes to a thorough understanding of these nanomaterials enabling the development of novel tailor-made materials and hence optimizing their applicability significantly

The HALO Submicrometer Aerosol Inlet (HASI): Design concept and first characterization

The HALO Submicrometer Aerosol Inlet (HASI) was specifically designed for HALO with the aim to provide up to 30 l/min sample air flow (divided over four forward facing sample lines) to aerosol instruments mounted inside the aircraft cabin. HASI samples the air on the top of the fuselage outside of the aircraft boundary layer. The air stream is aligned in the inlet and deaccelerated in three stages by roughly a factor of 40 using a front shroud, a main diffusor and smaller diffusers at the tips of four sample tubes which protrude into the deaccelerated air stream. In addition, there is a backward-facing sample tube installed for optional use. The design concept is to allow regulating the sample air flow in each of the four forward-facing sample lines to achieve isokinetic sampling conditions according to the actual speed of the aircraft. Pumps and bypass lines for regulation of the air flow are part of the Aerosol Measurement System (AMETYST) cabin rack on HALO operated by DLR. The geometric design of the inlet should prevent large cloud droplets and ice crystals from entering the sample lines directly. Judging from the first measurements of different instruments using HASI during the ML-CIRRUS and ACRIDICON-CHUVA missions with HALO, it appears that condensation particle counter (CPC) measurements of interstitial aerosol in liquid clouds are affected by artefacts while in ice clouds there is no indication of any measurement problem. Selected examples of other measurement results for initial experimental characterization of the inlet will be discussed. In order to achieve better isokinetic sampling, further numerical flow simulations of the final inlet design for different aircraft altitudes and speeds are required to establish a final regulation of the sample air flow in each of the four sample lines based on pressure and temperature sensors in the inlet and aircraft data

Rüstzeitoptimierung: Flexibel durch minimale Rüstzeit. Verschlanken Sie Ihre Produktion!: Wie man mit einfachen Mitteln Rüstzeiten optimiert. Fraunhofer IPA Workshop, Seminar für die Praxis, 13. Oktober 2009, Stuttgart

Wer nach flexiblem Kundenbedarf produziert, muss in der Lage sein, das laufende Produktionsprogramm kontinuierlich zu verändern. Man muss in wenigen Minuten umrüsten können, um eben das zu produzieren, was der Kunde verlangt. Dazu ist es erforderlich, eine große Vielfalt von Werkstücken und Teilen in kleinen Losen herstellen zu können. Entsprechend gering müssen die Rüstanteile sein. Oft wird die Ansicht vertreten, dass geringe Rüstzeiten zu teuer sind, weil sie durch kostspielige technische Verbesserungen erkauft werden müssen. Die praktische Erfahrung zeigt jedoch, dass oft bis zu 50 Prozent der Rüstzeiten mit einem sehr geringen Aufwand zu reduzieren sind. Wenn man dieses Potenzial ausschöpft, kann man im ersten Schritt die gewohnten Losgrößen halbieren und massiv an Produktivität in der Produktion zulegen. Die wesentlich höhere Flexibilität steigert die Wettbewerbsfähigkeit. Bei konsequenter Umsetzung schlägt sich der Erfolg deutlich in den Bestandskosten nieder. Es wird in diesem Workshop an praktischene Beispielen gezeigt, wie organisatorische Maßnahmen und Lerneffekte bei den Mitarbeitern mit einem relativ geringen Kostenaufwand die größten Verbesserungspotenziale bieten. Technische Verbesserungen werden dann zusätzlich stufenweise vorgenommen bis schließlich der Rüstvorgang einen Bruchteil der ursprünglichen Zeit dauert