2,042 research outputs found

    Differential infrared thermography for rotor aerodynamics

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    Understanding the flow around helicopter rotors is one of the greatest challenges in modern aerodynamics. The flow field plays a key role in the rotorcraft performance and operational safety, and it is characterized by highly unsteady and three-dimensional phenomena. State-of-the-art computational fluid dynamics (CFD) is applied during the design of future rotorcraft and offers remarkable capabilities, including the simulation of entire helicopter configurations in maneuvering flight. Nevertheless, experiments are still essential for the understanding of complex flow regimes, and for the validation of numerical results. An ever-increasing level of detail in CFD studies motivates the development and refinement of experimental methods, and combined experimental-numerical efforts have been particularly rewarding in recent studies. Starting with early rotorcraft-specific research topics, for example the systematic characterization of pitch-oscillating airfoils in the 1960s, experimental techniques have undergone continuous improvement. This particularly holds true for optical methods, which have developed from providing qualitative and “simple” snapshots of the flow into quantitative and time-resolving diagnostic tools. Optical methods require few modifications of the rotor or rotorcraft under investigation. They are particularly suitable for an application on multiple scales, ranging from small-scale laboratory studies to full-scale free-flying helicopters. This thesis concentrates on the development, validation, and application of the differential infrared thermography (DIT). The DIT method is able to determine the moving position of the laminar-turbulent boundary layer transition, which is a relevant aerodynamic feature on rotor blades, accounting for the unsteadiness introduced by the different inflow conditions on the advancing and retreating sides of the trimmed rotor plane in forward flight. Additional helicopter-relevant applications include the study of pitch-oscillating airfoils or small-scaled rotors in laboratory or wind-tunnel environments. Furthermore, it will be shown that the DIT principle can be adapted to other rotor-relevant topics beyond transition research, such as dynamic stall investigations. DIT is a valuable addition to the larger family of optical measurement techniques for aerodynamic applications

    Эмоциональный интеллект и необходимость его оценки при приеме сотрудника на работу

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    В статье поставлена задача изучения понятия "эмоциональный интеллект", выявление необходимости его оценки и учета при приеме на работу. Для решения данной задачи проведен анализ влияния уровня эмоционального интеллекта на работоспособность сотрудника, изучены исследования зарубежных психологов в данной области. Кроме этого, рассмотрен опыт зарубежных и отечественных компаний поиспользованию фактора эмоционального интеллекта в своей деятельности, в том числе при приеме на работу сотрудников

    Krüppel-like zinc finger proteins in end-stage COPD lungs with and without severe alpha1-antitrypsin deficiency

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    ABSTRACT: BACKGROUND: Chronic obstructive pulmonary disease (COPD) is influenced by environmental and genetic factors. An important fraction of COPD cases harbor a major genetic determinant, inherited ZZ (Glu342Lys) alpha1-antitrypsin deficiency (AATD). A study was undertaken to investigate gene expression patterns in end-stage COPD lungs from patients with and without AATD. METHODS: Explanted lungs of end-stage ZZ AATD-related (treated and non-treated with AAT augmentation therapy) and "normal" MM COPD, and liver biopsies from patients suffering from liver cirrhosis with and without ZZ AATD were used for gene expression analysis by Affymetrix microarrays or RT-PCR. RESULTS: A total of 162 genes were found to be differentially expressed (p-value [less than or equal to] 0.05 and |FC| [greater than or equal to] 2) between MM and ZZ COPD patients. Of those, 134 gene sets were up-regulated and 28 were down-regulated in ZZ relative to MM lung tissue. A subgroup of genes, zinc finger protein 165, snail homolog 1 (Drosophila) (SNAI1), and Kruppel-like transcription factors (KLFs) 4 (gut), 9 and 10, perfectly segregated ZZ and MM COPD patients. The higher expression of KLF 9 and KLF10 has been verified in the replication cohort with AATD-related end-stage lung emphysema and liver cirrhosis. Furthermore, higher expression of KLF9, SNAI1 and DEFA1 was found in ZZ COPD lungs without augmentation therapy relative to MM COPD or ZZ COPD with augmentation therapy. CONCLUSIONS: These results reveal the involvement of transcriptional regulators of the zinc-finger family in COPD pathogenesis and provide deeper insight into the pathophysiological mechanisms of COPD with and without AATD

    Impact of the first COVID lockdown on accident- and injury-related pediatric intensive care admissions in Germany - a multicenter study

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    Children’s and adolescents’ lives drastically changed during COVID lockdowns worldwide. To compare accident- and injury-related admissions to pediatric intensive care units (PICU) during the first German COVID lockdown with previous years, we conducted a retrospective multicenter study among 37 PICUs (21.5% of German PICU capacities). A total of 1444 admissions after accidents or injuries during the first lockdown period and matched periods of 2017–2019 were reported and standardized morbidity ratios (SMR) were calculated. Total PICU admissions due to accidents/injuries declined from an average of 366 to 346 (SMR 0.95 (CI 0.85–1.05)). Admissions with trauma increased from 196 to 212 (1.07 (0.93–1.23). Traffic accidents and school/kindergarten accidents decreased (0.77 (0.57–1.02 and 0.26 (0.05–0.75)), whereas household and leisure accidents increased (1.33 (1.06–1.66) and 1.34 (1.06–1.67)). Less neurosurgeries and more visceral surgeries were performed (0.69 (0.38–1.16) and 2.09 (1.19–3.39)). Non-accidental non-suicidal injuries declined (0.73 (0.42–1.17)). Suicide attempts increased in adolescent boys (1.38 (0.51–3.02)), but decreased in adolescent girls (0.56 (0.32–0.79)). In summary, changed trauma mechanisms entailed different surgeries compared to previous years. We found no evidence for an increase in child abuse cases requiring intensive care. The increase in suicide attempts among boys demands investigation

    Design of a dual species atom interferometer for space

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    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species 85^{85}Rb/87^{87}Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for 101110^{-11} mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (819 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.Comment: 30 pages, 23 figures, accepted for publication in Experimental Astronom

    Terrestrial Very-Long-Baseline Atom Interferometry:Workshop Summary

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    This document presents a summary of the 2023 Terrestrial Very-Long-Baseline Atom Interferometry Workshop hosted by CERN. The workshop brought together experts from around the world to discuss the exciting developments in large-scale atom interferometer (AI) prototypes and their potential for detecting ultralight dark matter and gravitational waves. The primary objective of the workshop was to lay the groundwork for an international TVLBAI proto-collaboration. This collaboration aims to unite researchers from different institutions to strategize and secure funding for terrestrial large-scale AI projects. The ultimate goal is to create a roadmap detailing the design and technology choices for one or more km-scale detectors, which will be operational in the mid-2030s. The key sections of this report present the physics case and technical challenges, together with a comprehensive overview of the discussions at the workshop together with the main conclusions
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