Vortex Developments Over an Accelerated Airfoil at High Angles of Attack

Proper control of unsteady separated flow developments over the lifting surfaces of an aircraft may prove to be an effective method of enhancing aerodynamic lift and producing better aircraft performance. Due to the complexity of unsteady flow separation and subsequent flow developments, experimental exploration and observation are essential in providing a source for comparison and verification with theoretical and computational models. In light of these motivations, a new experimental system that is capable of generating wide of range of unsteady flow histories has been developed and employed to visualize flow developments over an airfoil in accelerated-decelerated motion. The paper presents a description of the experimental system and its use in investigating accelerating flow over a flat plate airfoil at high angles of attack. The experimental results reported in the paper may serve as a useful source to guide and verify computational research efforts that are currently in progress

Filtering the noise from time series and spatial data

Noisy observations form the basis for almost every scientific research and especially in environmental monitoring. The noise is often an effect of imprecise instruments which cause measurement errors. If the noise variance is known it is possible to filter out the contaminating noise from the observations and then to predict the latent signal process. Solutions for this problem exist for time series application and will be briefly reviewed. In the geostatistical literature, i.e. for the analysis of spatial data, similar methods have been foreshadowed in the literature and will be outlined in this work. (orig.)SIGLEAvailable from TIB Hannover: RR 8460(1998,18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Engineering large in-plane tensile strains in ge microdisks, microrings and racetrack optical cavities

Highly strained Ge micro-cavities are demonstrated, with biaxial equivalent tensile strains > 2 % at the top surface, demonstrating photoluminescence up to the detector cut-off of 2.5 μm wavelength. Ge on Si micro-disk, rings, and racetrack structures are investigated, which have been undercut by wet etching techniques. The anisotropy of the wet etch in the Si leads to the realization of novel, partially suspended structures. The strain distributions in the different cavity structures are discussed and compared with regard to the in-plane uniformity, peak strain level, and effect of the strain distribution on the Ge band-structure

Dynamism and inertia on the Russian labour market A model of segmentation

SIGLEAvailable from British Library Document Supply Centre-DSC:3597.9512(2224) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

GaAs nanostructures on Si platform

Effective monolithic integration strategies for high quality quantum III-V nanostructure fabrication on Si will be introduced. The methodologies presented range from ultrathin planar Ge virtual substrates for the integration of single photon emitters with high temperature stability to advanced three-dimensional Ge growths strategies

Poly[(μ4-phenylphosphonato)zinc(II)]

The title two-dimensional coordination polymer, [Zn(C6H5PO3)]n, was synthesized serendipitously by reacting a tetraphosphonate cavitand Tiiii[C3H7, CH3, C6H5] and Zn(CH3COO)22H2O in a DMF/H2O mixture. The basic conditions of the reaction cleaved the phosphonate bridges at the upper rim of the cavitand, making them available for reaction with the zinc ions. The coordination polymer can be described as an inorganic layer in which zinc coordinates the oxygen atoms of the phosphonate groups in a distorted tetrahedral environment, while the phenyl groups, which are statistically disordered over two orientations, point up and down with respect to the layer. The layers interact through van der Waals interactions. The crystal studied was refined as a two-component twin

Surgeons' perspectives on artificial intelligence to support clinical decision-making in trauma and emergency contexts: results from an international survey

Background: Artificial intelligence (AI) is gaining traction in medicine and surgery. AI-based applications can offer tools to examine high-volume data to inform predictive analytics that supports complex decision-making processes. Time-sensitive trauma and emergency contexts are often challenging. The study aims to investigate trauma and emergency surgeons' knowledge and perception of using AI-based tools in clinical decision-making processes. Methods: An online survey grounded on literature regarding AI-enabled surgical decision-making aids was created by a multidisciplinary committee and endorsed by the World Society of Emergency Surgery (WSES). The survey was advertised to 917 WSES members through the society's website and Twitter profile. Results: 650 surgeons from 71 countries in five continents participated in the survey. Results depict the presence of technology enthusiasts and skeptics and surgeons' preference toward more classical decision-making aids like clinical guidelines, traditional training, and the support of their multidisciplinary colleagues. A lack of knowledge about several AI-related aspects emerges and is associated with mistrust. Discussion: The trauma and emergency surgical community is divided into those who firmly believe in the potential of AI and those who do not understand or trust AI-enabled surgical decision-making aids. Academic societies and surgical training programs should promote a foundational, working knowledge of clinical AI