Aerodynamics of Solar Vehicles

The purpose of this research project is to design the shape of a fully road worthy vehicle operating under nothing but the power of the sun. This vehicle was to meet all racing regulations of The Sunrayce and the World Solar Challenge. Because of the specific use of this vehicle, this project provides a chance to explore the aerodynamically ideal vehicle. Little attention has to be paid to practicality. The result is a very streamlined, highly aerodynamically efficient car, that is still stable and safe

An Investigation Between Tornadic and Non-Tornadic QLCS Mesovortices using Operational and Experimental MRMS Products

Quasi-linear convective system (QLCS) tornadoes have become an active area of research over the last several years. Through numerical simulations, it is theorized that QLCS vortex formation occurs near the surface in a quick response to heterogeneities along the baroclinic zone at the leading edge of the system. The mechanisms responsible for the development of vorticity in the lowest tens of meters involve storm-scale processes such as downdrafts, rear inflow jets, and friction from land interactions. The Multi-Radar Multi-Sensor (MRMS) systems contain operational algorithms that can observe storm-scale dynamic features taking advantage of the quality of the WSR-88D network. Blending numerous WSR-88D radars surrounding a target QLCS can provide a more complete three-dimensional image compared to a single radar view that captures storm-scale characteristics at both the low and upper levels, blended onto a 0.01 degree latitude by 0.01 degree longitude (~1 km) and 0.005 degree latitude by 0.005 degree longitude (~500 m) horizontal grid space. This study highlights testing of currently operational (e.g., dual-pol products and azimuthal shear) and experimental MRMS products (e.g., divergent shear and total shear) that aid in detecting QLCS meso-gamma-scale (2–40 km) vortices and subsequent tornadoes in both the pre-tornadic and tornadic phases. A total of 107 tornadic and 139 non-tornadic mesovortices are examined over 13 QLCS events spanning from 2019 through 2022. It was found that tornadic mesovortices often display deep, transient plumes of significantly enhanced cyclonic shear relative to non-tornadic mesovortices during the pre-tornadic phase. Further, signals displaying a significantly higher magnitude of mid-to-upper level divergence and low-to-mid level specific differential phase (KDP) is illustrated, indicative of transient precipitation-loaded updraft pulses manifesting during the hour prior tornadogenesis. Additionally, the ambient environment in which tornadic mesovortices manifest are characterized with steeper most unstable lifted condensation level (MULFC) lapse rates and higher surface-based CAPE relative to their non-tornadic counterpart. Higher 0–3 km AGL and 0–6 km AGL are also evident in tandem with higher 0–1 km AGL and 0–3 km AGL storm relative helicity (SRH). Non-tornadic mesovortices are often characterized with a higher magnitude of cyclonic shear and convergent shear at the near-surface relative to their tornadic counterpart during the period prior to their peak in 0–1 km AGL layer-maximum azimuthal shear. High variability and significant overlap in the interquartile range exists for all operational and experimental products for all tornadic and non-tornadic mesovortices retained in the dataset, indicating that the processes involved in QLCS tornado formation can vary on a case-by-case basis. A total of 107 tornadic and 139 non-tornadic mesovortices are examined over 13 QLCS events spanning from 2019 through 2022. It was found that tornadic mesovortices often display deep, transient plumes of significantly enhanced cyclonic shear relative to non-tornadic mesovortices during the pre-tornadic phase. Further, signals displaying a significantly higher magnitude of mid-to-upper level divergence and low-to-mid level specific differential phase (KDP) is illustrated, indicative of transient precipitation-loaded updraft pulses manifesting during the hour prior tornadogenesis. Additionally, the ambient environment in which tornadic mesovortices manifest are characterized with steeper most unstable lifted condensation level (MULFC) lapse rates and higher surface-based CAPE relative to their non-tornadic counterpart. Higher 0–3 km AGL and 0–6 km AGL are also evident in tandem with higher 0–1 km AGL and 0–3 km AGL storm relative helicity (SRH). Non-tornadic mesovortices are often characterized with a higher magnitude of cyclonic shear and convergent shear at the near-surface relative to their tornadic counterpart during the period prior to their peak in 0–1 km AGL layer-maximum azimuthal shear. High variability and significant overlap in the interquartile range exists for all operational and experimental products for all tornadic and non-tornadic mesovortices retained in the dataset, indicating that the processes involved in QLCS tornado formation can vary on a case-by-case basis

Der Einfluss der anatomischen Subgruppen beim hypoplastischen Linksherzsyndrom auf die globale und regionale Funktion des rechten Ventrikels

Das Hypoplastische Linksherzsyndrom ist ein sehr schwerer kongenitaler Herzfehler, der mit einer Inzidenz von ca. 1:5000 beschrieben ist. Dieser angeborene Herzfehler ist bedingt durch eine Entwicklungsfehlbildung, die mit einer Hypoplasie der linken Herzhälfte einhergeht. Der linke Ventrikel und die aszendierende Aorta sind deutlich hypoplastisch und Mitral- und Aortenklappe sind stenotisch oder atretisch. Ohne Behandlung führt das HLHS innerhalb weniger Tage zum Tode des Neugeborenen, da der linke Ventrikel nicht in der Lage ist, ein ausreichendes systemisches Herzminutenvolumen zu pumpen. Die Körperperfusion ist vom offenen Ductus arteriosus und offenem Foramen ovale abhängig und wird vom rechten Ventrikel getragen. Als operative Behandlung der Wahl gilt heutzutage die herzerhaltende dreistufige Operation mit dem Ziel einer Hintereinanderschaltung von Lungen- und Körperkreislauf mittels totaler kavopulmonaler Anastomose. Nach Beendigung der operativen Palliation befinden sich die HLHS-Patienten im sog. Fontankreislauf, benannt nach dem Namen der letzten dreistufigen Operation, der Fontan-Operation. Entscheidend für Morbidität und Mortalität der Kinder mit HLHS ist die rechtsventrikuläre Funktion. Das Ziel der Studie ist die Untersuchung der regionalen und globalen Ventrikelfunktion bei HLHS in Bezug zur anatomischen Subgruppe mittels MRT. Es ist geplant ca. 60 Kinder mit HLHS, die sich im Fontankreislauf befinden, zu untersuchen. Zur tomographischen Analyse der Ventrikelfunktion werden schnelle Gradienten-Echo-Cine-Sequenzen in 25 Phasen mit einer Schichtdicke von 5mm, einer Matrix von 240x260 mm und folgenden Parametern (TR/TE/α =1,1/1,6/60) verwendet. Die Vitalparameter werden mittels Monitoring während der gesamten Untersuchungsdauer überwacht. Alle Messungen erfolgen auf nichtinvasive Weise mit einem MR-kompatiblen Patientenüberwachungsmonitor. Mit Hilfe spezieller Software werden die gewonnenen Daten analysiert. Für die globale Funktion des rechten Ventrikels wird das enddiastolische, sowie das endsystolische Volumen, das Schlagvolumen, der Cardiac Index und der Cardiac Out Put genutzt. Die regionalen Funktionsparameter stellen die Wandverdickung,-dicke und -bewegung dar. Für die Quantifizierung der regionalen Parameter wird der rechte Ventrikel in allen Schichten in vier Segmenten eingeteilt. Die vier Segmente beschreiben folgende Segmentierung: Segment 1= Septum, Segment 2 = inferiores Myokard, Segment 3 = Vorderwand, Segment 4 = apikales Myokard, wobei lediglich die Segmente 1 und 3 für die Funktionsanalyse des rechten Ventrikels genutzt werden