Search results for "Steering"
showing 10 items of 33 documents
Ultrafast beam shaping with high-numerical-aperture microscope objectives
2009
Ultrafast diffraction results in spatiotemporal un-coupling of the wave field, inducing spectral anomalies and pulse stretching. Localized compensation may be achieved via angular dispersion driven by diffractive optical elements (DOEs). We report on an DOEs-based beam shaper of ultrashort optical pulses with high spatiotemporal resolution. Inspection of the validity of our approach is performed in the single-cycle regime.
Spectroscopic response of a CdZnTe multiple electrode detector
2007
Abstract The spectroscopic performances of a CdZnTe detector (crystal size: 5×5×0.9 mm 3 ) with five electrodes (cathode, anode and three steering electrodes) were studied. The anode layout, which consists of a circular electrode ( φ =80 μm) surrounded by two ring electrodes (gap=100 μm; radial width Δ r =100 μm) and by one electrode that extends to the edge of the crystal, is mostly sensitive to the electron carriers, overcoming the well known effect of the hole trapping in the measured spectra. We report on the spectroscopic response of the detector at different bias voltages of the electrodes and at various photon energies ( 109 Cd, 241 Am and 57 Co sources). The CdZnTe detector exhibits…
How Can Steering Committees Manage Change Through Dynamic Capabilities to Increase System Satisfaction?
2017
Determinants of diagnostic delay in chronic thromboembolic pulmonary hypertension: results from the European CTEPH Registry.
2018
Chronic thromboembolic pulmonary hypertension (CTEPH) is characterised by chronic thrombi in the pulmonary arterial bed, causing pulmonary hypertension [1–3]. CTEPH is diagnosed in ∼3% of patients who survive a symptomatic acute pulmonary embolism (PE) [4]. While the surgical removal of chronic fibrotic thrombotic vascular occlusions by pulmonary endarterectomy (PEA) may cure most patients with CTEPH by normalising pulmonary artery hemodynamics and improving symptoms, patients who remain not operated or do not undergo balloon pulmonary angioplasty have severe functional limitations, and poor quality of life and survival [5, 6]. Since the natural course of CTEPH involves progressive remodell…
Selective Actuation and Tomographic Imaging of Swarming Magnetite Nanoparticles
2021
International audience; Micro- and nanomotors have seen substantial progress in recent years for biomedical applications. However, three grand challenges remain: (i) high velocities to overcome the blood flow, (ii) spatially selective control to enable complex navigation, and (iii) integration of a medical, tomographic real-time imaging method to acquire feedback information. Here, we report the combination of active magnetic matter and a medical imaging technique, namely magnetic particle imaging (MPI), which addresses these needs. We synthesize ∼200 nm magnetic nanoparticles and observe a macroscopic, collective effect in a homogeneous magnetic field with a rotating field vector. The nano…
A Checklist for Assessing the Methodological Quality of Concurrent tES-fMRI Studies (ContES Checklist): A Consensus Study and Statement
2020
AbstractBackgroundLow intensity transcranial electrical stimulation (tES), including alternating or direct current stimulation (tACS or tDCS), applies weak electrical stimulation to modulate the activity of brain circuits. Integration of tES with concurrent functional magnetic resonance imaging (fMRI) allows for the mapping of neural activity during neuromodulation, supporting causal studies of both brain function and tES effects. Methodological aspects of tES-fMRI studies underpin the results, and reporting them in appropriate detail is required for reproducibility and interpretability. Despite the growing number of published reports, there are no consensus-based checklists for disclosing …
Resonant Beam Steering and Carpet Cloaking Using an Acoustic Transformational Metascreen
2018
International audience; We invoke the Huygens principle to derive dispersion characteristics of acoustic transformational meta-surfaces that can deflect parallel wavefronts in a desired direction. We also propose a dual-Lorentz resonator whose aperture fields can be tuned by geometrical changes to implement a particular phase with unity reflection coefficient. The proposed metascreen is designed by our arranging slightly detuned Lorentz cavities that generate the necessary interference to compensate for the incident wavefronts. Since a complete 0-2 pi range of the reflection phase is achieved, the metascreen can steer a beam across the full horizon. Moreover, since the proposed dual resonat…
Hybridity in Nordic Higher Education
2022
This article builds on the concept of nested hybridity. It emphasizes professional practices and organizational design in studying hybridity of steering and management of professional public service organization. The article compares public sector dynamics in higher education in Finland, Norway, and Sweden. The data consists of surveys and interviews on performance management in Nordic universities. Previous studies on hybridity of professional work and public organizations define hybridity as a multidimensional concept that occurs at different levels of social practices. While the multifaceted nature of hybridity is clear, demarcating between levels of hybridity and theoretical approaches …