Airborne forward pointing UV Rayleigh lidar for remote clear air turbulence (CAT) detection: system design and performance

A high-performance airborne UV Rayleigh lidar system was developed within the European project DELICAT. With its forward-pointing architecture it aims at demonstrating a novel detection scheme for clear air turbulence (CAT) for an aeronautics safety application. Due to its occurrence in clear and clean air at high altitudes (aviation cruise flight level), this type of turbulence evades microwave radar techniques and in most cases coherent Doppler lidar techniques. The present lidar detection technique relies on air density fluctuations measurement and is thus independent of backscatter from hydrometeors and aerosol particles. The subtle air density fluctuations caused by the turbulent air flow demand exceptionally high stability of the setup and in particular of the detection system. This paper describes an airborne test system for the purpose of demonstrating this technology and turbulence detection method: a high-power UV Rayleigh lidar system is installed on a research aircraft in a forward-looking configuration for use in cruise flight altitudes. Flight test measurements demonstrate this unique lidar system being able to resolve air density fluctuations occurring in light-to-moderate CAT at 5 km or moderate CAT at 10 km distance. A scaling of the determined stability and noise characteristics shows that such performance is adequate for an application in commercial air transport.Comment: 17 pages, 19 figures. Pre-publish to Applied Optics (OSA

Institutions politiques et Droit constitutionnel II (2020-2021) - Plan général du cours (Partie droit constitutionnel)

Le présent document est le plan général relatif à la partie "Droit constitutionnel" du cours d'Institutions politiques et Droit constitutionnel II

Le principe de légalité de l’article 23 de la Constitution, en matière de droits économiques, sociaux et culturels

L’article 23 de la Constitution charge les législateurs compétents de garantir les droits économiques, sociaux et culturels. La question est de savoir si ces législateurs peuvent déléguer largement cette mission au pouvoir exécutif (c'est-à-dire au gouvernement), ou s’ils doivent eux-mêmes en régler les aspects les plus essentiels. La Cour constitutionnelle a adopté une position médiane. Selon elle, l’article 23 de la Constitution contient bien un principe de légalité, imposant l’intervention d’une assemblée délibérante démocratiquement élue, mais celui-ci a une portée (très) limitée. Il semble que cette jurisprudence s’explique par l’absence de volonté claire du constituant, en 1994, d'instaurer un principe de légalité strict dans ces matières, ainsi que par la circonstance que les matières concernées sont habituellement réglées dans une large mesure par le pouvoir exécutif, en raison de leur caractère technique et évolutif. Cette jurisprudence de la Cour constitutionnelle est battue en brèche par la doctrine ainsi que par la section de législation du Conseil d’État, quoique de manière plus voilée. Ces critiques invitent à se demander si un revirement de jurisprudence de la Cour sur ce point est opportun et/ou souhaitable

Scaling Milton Keynes power requirements for electrical transportation

Milton Keynes is home to the UK’s first installation of a wirelessly charged passenger bus route. This Inductive Power Transfer (IPT) system enables a fleet of 8 electric buses to service a demanding 15-mile urban route. Opportunistic wireless charging of the batteries during the layover time at the routes allows reducing the size of the batteries, consequently improving cost and performance characteristics of the bus. This paper aims to analyze the effects of electric buses on the electricity distribution grid. In particular, the paper analyses scalability of the IPT solution to all urban routes in Milton Keynes and compares peak power requirements generated at different points in the network with typical industrial and commercial (I&C) loads

Principes de Droit constitutionnel belge

Ouvrage constituant le syllabus officiel pour le cours de Droit constitutionnel (DROI1203-4) en baccalauréat en droit de l'Université de Liège, Faculté de Droit

Intrinsic and Extrinsic Geometry of Ovaloids and Rigidity

Our main result is that an ovaloid with nowhere dense umbilics and prescribed Weingarten operator and spherical volume form is rigid in Euclidean 3-space. In case of an ovaloid of revolution we can drop the assumption on the volume form

Skin substitutes : a step forward in skin regeneration using tissue engineering

editorial reviewedL’utilisation des substituts cutanés dans la chirurgie des grands brûlés et dans le traitement des plaies aiguës ou chroniques est en constante évolution. Depuis des années, les scientifiques recherchent des substituts cutanés qui peuvent être utilisés à la place de la peau autologue. De nouveaux produits sont régulièrement développés et approuvés pour l’utilisation clinique. Dans cet article, nous examinons les substituts cutanés les plus utilisés en Europe et résumons brièvement l’expérience pratique de notre centreThe use of skin substitutes in burn surgery and in the treatment of acute or chronic wounds is constantly evolving. For years, scientists have been researching skin substitutes that can be used in place of autologous skin. New products are regularly developed and approved for clinical use. In this article, we take a look at the skin substitutes most commonly used in Europe and briefly summarize the current clinical experience of our centre

Improving psychotropic drug prescription in nursing home patients with dementia:design of a cluster randomized controlled trial

Background: Neuropsychiatric symptoms are highly prevalent in nursing home patients with dementia. Despite modest effectiveness and considerable side effects, psychotropic drugs are frequently prescribed for these neuropsychiatric symptoms. This raises questions whether psychotropic drugs are appropriately prescribed. The aim of the PROPER (PRescription Optimization of Psychotropic drugs in Elderly nuRsing home patients with dementia) II study is to investigate the efficacy of an intervention for improving the appropriateness of psychotropic drug prescription in nursing home patients with dementia.Methods/design: The PROPER II study is a multi-center cluster randomized controlled, pragmatic trial using parallel groups. It has a duration of eighteen months and four six-monthly assessments. Six nursing homes will participate in the intervention and six will continue care as usual. The nursing homes will be located throughout the Netherlands, each participating with two dementia special care units with an average of fifteen patients per unit, resulting in 360 patients. The intervention consists of a structured and repeated multidisciplinary medication review supported by education and continuous evaluation. It is conducted by pharmacists, physicians, and nurses and consists of three components: 1) preparation and education, 2) conduct, and 3) evaluation/guidance. The primary outcome is the proportion of patients with appropriate psychotropic drug use. Secondary outcomes are the overall frequency of psychotropic drug use, neuropsychiatric symptoms, quality of life, activities of daily living, psychotropic drug side effects and adverse events (including cognition, comorbidity, and mortality). Besides, a process analysis on the intervention will be carried out.Discussion: This study is expected to improve the appropriateness of psychotropic drug prescription for neuropsychiatric symptoms in nursing home patients with dementia by introducing a structured and repeated multidisciplinary medication review supported by education and continuous evaluation.</p

Abundance analysis of prime B-type targets for asteroseismology I. Nitrogen excess in slowly-rotating beta Cephei stars

We present the results of a detailed NLTE abundance study of nine beta Cephei stars, all of them being prime targets for theoretical modelling: gamma Peg, delta Cet, nu Eri, beta CMa, xi1 CMa, V836 Cen, V2052 Oph, beta Cep and DD (12) Lac. The following chemical elements are considered: He, C, N, O, Mg, Al, Si, S and Fe. Our abundance analysis is based on a large number of time-resolved, high-resolution optical spectra covering in most cases the entire oscillation cycle of the stars. Nitrogen is found to be enhanced by up to 0.6 dex in four stars, three of which have severe constraints on their equatorial rotational velocity, \Omega R, from seismic or line-profile variation studies: beta Cep (\Omega R~26 km/s), V2052 Oph (\Omega R~56 km/s), delta Cet (\Omega R < 28 km/s) and xi1 CMa (\Omega R sin i < 10 km/s). The existence of core-processed material at the surface of such largely unevolved, slowly-rotating objects is not predicted by current evolutionary models including rotation. We draw attention to the fact that three stars in this subsample have a detected magnetic field and briefly discuss recent theoretical work pointing to the occurrence of diffusion effects in beta Cephei stars possibly capable of altering the nitrogen surface abundance. On the other hand, the abundances of all the other chemical elements considered are, within the errors, indistinguishable from the values found for OB dwarfs in the solar neighbourhood. Despite the mild nitrogen excess observed in some objects, we thus find no evidence for a significantly higher photospheric metal content in the studied beta Cephei stars compared to non-pulsating B-type stars of similar characteristics.Comment: Accepted for publication in A&A, 21 pages, 7 figure