The three approaches followed herein aim to improve our understanding of the paleobiodiversity andevolution of Silurian radiolarians. The first approach provides an exhaustive taxonomic description ofan entirely new radiolarian fauna recovered from two sections of the Cape Phillips Formation in theCanadian Arctic which accumulated in two different paleoenvironmental settings. The samples are datedby graptolites of the Gorstian Lobograptus progenitor Zone. The obtained radiolarian fauna includes 28species, of which 3 are new, and exhibits some of the best preserved Silurian radiolarians known so far.The stratigraphic range of several species was also extended. Then, in a second approach, a CT-Scan3D reconstruction of a specimen of Gyrosphaera cavea was conducted in order to resolve significantinternal structure taxonomic issues. Higher level radiolarian classification is based on internal structures,and classical methods of observing these features repeatedly failed to uncover them. The 3D imagingrevealed a «double» coiling of the specimen that has proved useful in understanding how it grew.Eventually, the third approach is a completion of published taxonomic works in the Silurian with theaim of providing diversity trends through analyses of these radiolarian occurrences. A biotic crisis canbe observed in the Homerian, exhibiting both high extinction and low origination rates, and may belinked with enhanced marine productivity. / De tre projekten som utvecklas här har som mål att fokusera på trender inom evolutionen ochmångfalden av en grupp planktoniska mikroorganismer från Silur (från -443 till -419 Ma). I ett förstaprojekt beskrivs en helt ny fauna radiolarier som hittats i två lokaliteter på de kanadensiska arktiskaöarna, och som har deponerats i olika miljöförhållanden under Silur. Detta material daterades med hjälpav graptoliter, en grupp utdöda svalgsträngsdjur som är mycket användbara för paleozoiska dateringar,till en ålder överensstämmande med Gorstian (-427 till -425 Ma). Denna kanadensisk-arktiska fauna avradiolarier består av 28 arter (varav 3 är nya) och uppvisar några av de bäst bevarade fossilerna frånSilur överhuvudtaget. Den stratigrafiska bredden, vilket är livstiden, av flera arter har också förlängts.Därefter, i ett andra projekt, skapades en 3D-rekonstruktion av ett exemplar av Gyrosphaera cavea medhjälp av mikrotomografi för att observera och beskriva komplexa interna strukturer. Faktum är attklassificeringen av Radiolaria består till stor del av analysen och beskrivningen av dessa internastrukturer och många klassiska metoder som har använts för att observera dem, såsom med hjälp avsvepelektronmikroskop, har misslyckats konsekvent. 3D-avbildningen visade en komplex dubbelrullandeav strukturen i exemplaret, som har visat sig vara användbart i sökandet för att förstå dennesutveckling. Det tredje projektet är slutförandet av en samling av samtliga publicerade arbeten röranderadiolarier från Silur med syfte att klargöra trender inom diversitet för hela perioden genom analyser avförekomsten av dessa radiolarier. Ett utdöende kan observeras under Homerian (-430 till -427 Ma), somtroligen orsakades av frekventa utdöenden och en låg artbildningshastighet.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Two different types of tracking feeds are currently used in the majority of telemetry tracking antenna systems when autotrack operation is required. They are of the conical scanner or of the single channel monopulse family and they employ well known technologies. In broadband applications, these feeds all suffer from the same inherent degradation in efficiency caused by their inability to maintain a constant crossover loss value and by their failure to properly illuminate the reflector. In high dynamics situations they can also generate unwanted and sometimes detrimental modulation whenever on-axis tracking is not maintained. In addition, currently available versions of the conical scanner are not capable of high scan rates or of scan rate agility and they are ill-suited for use in tracking systems based on non-orthogonal axes positioners. This paper describes a new high efficiency tracking feed system based on proven conical scanner technology. Its design incorporates features such as variable crossover, steerable beam, high scan rates, scan rate agility as well as stable reference coordinate system. In addition to these features, this new feed is also capable of delivering, in all but one operational category, levels of performance superior to that achievable to date by any other implementation of the conical scanner or of the single channel monopulse technology.

International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / In recent years, many designers have turned to digital techniques as a means of improving the fidelity of instrumentation data recorders. However, single and multi-channel recorders based on professional VHS transports are now available which use innovative methods for achieving near-perfect timebase accuracy, inter-channel timing and group delay specifications for long-duration wideband analog recording applications. This paper discusses some of the interesting technical problems involved and demonstrates that VHS cassette recorders are now a convenient and low cost proposition for high precision multi-channel wideband data recording.

A review of aeroplane spin literature is presented, including early spin research history and lessons learned from spinning trials. Despite many years of experience in spinning evaluation, it is difficult to predict spin characteristics and problems have been encountered and several prototype aeroplanes have been lost. No currently published method will reliably predict an aeroplane’s spin recovery characteristics. Quantitative data is required to study the spin motion of the aeroplane in adequate detail. An alternative method, Vision Based State Estimation, has been used to capture the spin motion. This alternative method has produced unique illustrations of the spinning research aeroplane and data has been obtained that could possibly be very challenging to obtain using traditional methods. To investigate the aerodynamic flow of a spinning aeroplane, flights have been flown using wool tufts on wing, aft fuselage and empennage for flow visualization. To complement the tuft observations, the differential pressure between the upper and lower horizontal tail and wing surfaces have been measured at selected points. Tufts indicate that a large-scale Upper Surface Vortex forms on the outside wing. This USV has also been visualized using a smoke source. The flow structures on top of both wings, and on top of the horizontal tail surfaces, have also been studied on another aeroplane model. The development of these rotational flow effects has been related to the spin motion. It is hypothesized that the flow structure of the turbulent boundary layer on the outside upper wing surface is due to additional accelerations induced by the rotational motion of the aeroplane. The dynamic effects have been discussed and their importance for the development of the spin considered. In addition, it is suggested that another dynamic effect might exist due to the additional acceleration of the turbulent boundary layer due to the rotational motion of the aeroplane. It is recommended that future spin recovery prediction methods account for dynamic effects, in addition to aerodynamic control effectiveness and aeroplane inertia, since the spin entry phase is important for the subsequent development of the spin. Finally, suggestions for future research are given.

Anthropometric quantities are widely used in epidemiologic research as possible confounders, risk factors, or outcomes. 3D laser-based body scans (BS) allow evaluation of dozens of quantities in short time with minimal physical contact between observers and probands. The aim of this study was to compare BS with classical manual anthropometric (CA) assessments with respect to feasibility, reliability, and validity. We performed a study on 108 individuals with multiple measurements of BS and CA to estimate intra- and inter-rater reliabilities for both. We suggested BS equivalents of CA measurements and determined validity of BS considering CA the gold standard. Throughout the study, the overall concordance correlation coefficient (OCCC) was chosen as indicator of agreement. BS was slightly more time consuming but better accepted than CA. For CA, OCCCs for intra- and inter-rater reliability were greater than 0.8 for all nine quantities studied. For BS, 9 of 154 quantities showed reliabilities below 0.7. BS proxies for CA measurements showed good agreement (minimum OCCC > 0.77) after offset correction. Thigh length showed higher reliability in BS while upper arm length showed higher reliability in CA. Except for these issues, reliabilities of CA measurements and their BS equivalents were comparable.

Dans la continuité des expériences SuperKamiokande et K2K, OPERA (Oscillation Project with Emulsion tRacking Apparatus), cherchera à confirmer l'oscillation des neutrinos dans le secteur atmosphérique. Utilisant une technique déjà employée dans CHORUS et DONUT, la chambre à brouillard d'émulsion (Emulsion Cloud Chamber (ECC)), cette expérience permettra la mise en évidence de l'oscillation nµ® nt par apparition de nt dans un faisceau pur de nµ.<br />L'expérience OPERA, avec ses ~100000 m2 d'émulsions nucléaires, nécessite l'utilisation de systèmes de scan automatiques ultra rapides. Les composantes optiques et mécaniques de ces systèmes ont été optimisées pour atteindre une vitesse de scan de ~20 cm2/heure par couche d'émulsion (44 μm d'épaisseur), tout en gardant une résolution sub-micrométrique.<br />Dans la première partie de mon travail de thèse, je me suis consacrée à l'optimisation des 4 systèmes de scan au sein de l'unique station de scan française basée à Lyon. Une étude expérimentale sur les performances d'un scan utilisant un objectif à sec a été également réalisée. Les résultats obtenus montrent que les performances d'un scan « à sec » sont similaires à celles d'un scan traditionnel utilisant un objectif à huile. <br />La deuxième partie de mon travail a consisté à valider la stratégie actuellement utilisée dans OPERA pour la localisation et la reconstruction des vertex de l'interaction des neutrinos, à l'aide d'un test sur faisceau dédié. Les résultats obtenus confirment définitivement que la stratégie proposée est bien adaptée à la recherche du lepton tau.

L'expérience OPERA propose de mettre en évidence l'oscillation par apparition du dans un faisceau pur en . Ce faisceau est produit au CERN, puis dirigé sur le détecteur situé à 732 km plus loin. Le détecteur OPERA est composé de deux spectromètres à muons et d'une cible formée de murs de briques qui sont une alternance de feuilles de plomb et d'émulsions. Cette structure permet de reconstruire avec une haute résolution spatiale la topologie de désintégration en coude du tau. Le grand défi de l'expérience OPERA est de pouvoir mettre en évidence les interactions avec le moins d'incertitude possible à travers l'identification de tout événement de bruit de fond ne comportant pas un . C'est à ce niveau que mon travail apporte une contribution intéressante en offrant la possibilité de réduire d'avantage le bruit de fond. Ma contribution principale d'analyse concerne le développement de la sélection, de la reconstruction et l'identification des muons de basse énergie à l'aide des émulsions nucléaires. Ce travail repose sur la mise en corrélation de variables sensibles à la fois à la perte d'énergie et à la diffusion multiple. Auparavant, seule l'énergie perdue était utilisée dans les analyses de séparation . Mon étude a permis de doubler l'efficacité d'identification des muons de basse énergie ce qui va permettre d'accroître la puissance de rejet des événements de bruit de fond et de diminuer la contamination de 30%. J'ai également étudié le pouvoir des émulsions dans l'identification et la séparation des particules chargées à travers l'analyse d'un test réalisé par le groupe de Nagoya au Japon contenant des protons et des pions de différentes énergies. J'ai montré que le système de scan Européen donne des résultats comparables aux résultats obtenus par le système de scan Japonais.

A polymer light-emitting electrochemical cell (LEC) is a solid-state polymer device operating according to in situ electrochemical doping and the formation of a light-emitting polymer p-n junction. This operating mechanism, however, has been the subject of much debate. Planar LECs with millimeter scale interelectrode spacings offer great advantages for directly observing the electrochemical doping process. Photoluminescence quenching and the formation of a light-emitting junction have been observed in planar polymer LECs, demonstrating the existence of electrochemical doping. The chemical potential difference between the p- and n-doped regions creates a built-in potential/electric field in the junction region, which can be probed by measuring the optical beam induced current (OBIC). This study utilizes a versatile and easy-to-use method of performing OBIC analysis. The OBIC and photoluminescence profiles of LECs have been simultaneously measured by scanning a focused light beam across large planar LECs that have been turned on and cooled to freeze the doping profile. The photoluminescence intensity undergoes a sharp transition between the p- and n-doped regions. The OBIC photocurrent is only observed in the transition region that is narrower than the width of the excitation beam, which is about 35 μm. The results depict a static planar polymer p-n junction with a built-in electric field pointing from n to p. The electrode interfaces do not produce a measurable photocurrent indicating ohmic contact. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2013-05-28 12:52:14.171

Texten är ett försök att hitta relevanta sätt att tala om måleri idag. Den presenterar personliga tankar och reflektioner om måleriets samtidshistoria och hur man skulle kunna definiera dess väsen och roll i konsten och samhället. / [I examensarbetet ingår utställningen "Slow Down Vision":] Utställningen består av målningar hängda på väggarna. En grupp målningar som föreställer digitala fotofilter hänger tillsammans på ena lång sidan. På de andra väggarna hänger målningar föreställande in scannade vardagliga objekt och två abstrakta målningar gjorda med hjälp av bubbelplast. I mitten av rummet står en bänk som man kan sitta på. Material: Måleri Teknik: Olja på duk

Years ago it was typical for a physician to serve as a hospital's Chief Executive Officer (CEO). However, with the development of Master of Health Administration, Master of Public Health, and Master of Business Administration programs, hospitals began to move away from this model. Today however, as hospitals search for innovative ideas to reduce healthcare costs and improve the quality of care, the idea of the physician hospital CEO has returned. Little empirical research is available in the health services literature on the physician hospital CEO. The study aims to examine the relationship between organizational and environmental factors and physician CEOs, and whether or not physician CEOs are associated with improved hospital performance.The conceptual framework is adapted from Donabedian's structure, process, and outcome perspective, which when applied to the organizational level becomes context design-performance. The theoretical perspective applied to the conceptual framework to guide the development of hypotheses is contingency theory, which suggests that organizations are most successful when they can adapt their structures to fit their environment.Data for this study were obtained from multiple sources: American Hospital Association Annual Survey, the Centers for Medicare and Medicaid Services Hospital Cost Reports, SK&A, Area Resource File, and the Centers for Medicare and Medicaid Services Hospital Quality Alliance.Besides descriptive analyses, logistic regression was used in this study to evaluate the relationship between the organizational and environmental hospital characteristics. Ordinary least squares regression was used to explore the relationship between physician CEOs and hospital performance.Results indicate that hospitals in markets with greater physician competition are more likely to have physician CEOs. Hospitals that are affiliated with a system are also more likely to have physician CEOs. The study found that while teaching hospitals and specialty hospitals were associated with placement of physician CEOs, it was in the opposite direction of what was hypothesized. This may be a result of the small sample size of both teaching and specialty hospitals in the study sample. The study concludedthat having a physician CEOs is associated with hospital financial outcomes but not associated with its quality of care outcomes.