Pavement stresses due to tire impact

Road surfaces wear continually under the effects of vehicular motions in an environment of changing temperature, humidity, etc. Regulatory agencies need to set limits on vehicular loads, tire pressures, etc., in order to mitigate the damage caused by the traveling stress footprints of vehicular traffic. In order to understand and quantify the relationship between damage caused and the parameters influencing the forces generated by a moving vehicle on a road surface, it is necessary to construct a model for a mechanical system of vehicle body, suspension springs, axle, wheel rim and tire, transmitting forces back and forward to the road surface. The previous paragraph describes the broad problem presented to the workshop. In what follows we organize a simple mathematical model to represent the major components of the system, and we indicate how this model may be validated (or not) by tests and, if it is successful, how it can be used in a predictive capacity

More Jets in more LHC searches

Multi jet observables are a powerful tool to new physics as well as a boost to standard analysis strategies. We show their use in a reasonably model independent dark matter search and a jet veto Higgs analysis. We find however that, these observables are plagued by huge theoretical uncertainties connected to unphysical scale parameters. In the democratic limit we compute analytically the all order resummed jet spectrum at leading log. It obeys so called staircase scaling. With the help of state of the art Monte Carlo tools we study the jet spectrum features in great detail. In addition we also study so called Poisson scaling. This allows us to develop a data driven strategy to fix the standard model multi jet backgrounds

Establishing jet scaling patterns with a photon

Staircase and Poisson scaling are two typical patterns we observe for the exclusive number of jets at high energy hadron colliders. We examine these scaling properties for photon plus jets production at the LHC and find that this channel is well suited to study these features. We illustrate and discuss when to expect each of the two patterns, how to induce a transition through kinematic cuts, and how photons are related to heavy gauge bosons. Measurements of photon+jets production is therefore providing valuable information on exclusive jet scaling, which is going to help to eventually understand the theoretical origin of exclusive jet scaling properties in more detail

Jets plus Missing Energy with an Autofocus

Jets plus missing transverse energy is one of the main search channels for new physics at the LHC. A major limitation lies in our understanding of QCD backgrounds. Using jet merging we can describe the number of jets in typical background channels in terms of a staircase scaling, including theory uncertainties. The scaling parameter depends on the particles in the final state and on cuts applied. Measuring the staircase scaling will allow us to also predict the effective mass for Standard Model backgrounds. Based on both observables we propose an analysis strategy avoiding model specific cuts which returns information about the color charge and the mass scale of the underlying new physics.Comment: 15 pages, 9 figures, 3 table

Preparation and impedance characterization of all-solid-state thin film battery systems

In this thesis the behavior and properties of solid-state batteries based on multiple electrodes are analysed. For this purpose thin film systems of the relevant materials are prepared to achieve model system for more detailed analysis of the material specific properties. The characterisation of the systems is carried out with typical physical and electrochemical methods and especially using impedance spectroscopy. The first material analysed in this thesis is Li4Ti5O12 which was recognized early on as an interesting candidate for an anode material for solid-state batteries due to its miniscule volume expansion during lithium insertion and extraction. For this material the preparation of thin film systems and the optimisation of preparation parameter is shown and special properties of the material in the system are discussed. Lithium titanate shows a clear two-phase behavior and the properties of the charged and discharged phase are vastly different. The main difference here is the ionic and electronic conductivity. The properties of the two phases are evaluated using impedance spectroscopy and conclusions about the phase transition are drawn from this data. The main point of discussion is between a phase transition based on a two-phase system or a solid solution system. Aside from the phase transition other properties of the system like the interaction between electrode and electrolyte are explained. It is shown that the resistance between electrode and electrolyte is miniscule but an additional electronic charge transfer between electrode and substrate material can form under certain circumstances. This phenomenon occurs due to the semiconducting, almost insulating nature of lithium titanate, which leads to extended space charge layers in the material. These space charge layers can also appear in contact with metal substrates and can hinder the cell performance for very thin electrode layers. In the second part of the thesis similar experiments are performed on another electrode material using lithium nickel manganese oxide. This material is of interest as cathode material due to its high working potential versus lithium metal. The work is mostly focused on the problems in electrode preparation, especially film adhesion, and evaluation of the interface between cathode and electrolyte. The data is interpreted in comparison to the data of lithium titanate and differences and similarities are highlighted. Additional the question of which phase of the material is deposited is exploded and how the interface between cathode and electrolyte changes in dependence of the utilized deposition method.Innerhalb dieser Arbeit wurde das Verhalten und die Eigenschaften von Festkörperbatterien basierend auf zwei verschiedenen Elektrodenmaterialien untersucht. Zu diesem Zweck wurden Dünnschichtsysteme der relevanten Materialien hergestellt um Modellsysteme für die nähere Untersuchung der materialspezifischen Eigenschaften zu erhalten. Die Charakterisierung der Systeme erfolgte dabei neben den typischen physikalischen und elektrochemischen Methoden im Wesentlichen über Impedanzspektroskopie. Zunächst wurde in der Arbeit Lithiumtitanat Li4Ti5O12 untersucht, das aufgrund seiner geringen Volumenausdehnung beim Lithiumein- und -ausbau schon früh als idealer Kandidat für die Anodenseite einer Festkörperbatterie betrachtet wurde. Für dieses Material wird die Herstellung der Schichtsysteme sowie die Optimierung der Herstellungsparameter gezeigt und anschließend auf die speziellen Eigenschaften des Materials innerhalb des Systems eingegangen. Lithiumtitanat zeigt in der Praxis ein deutliches Zweiphasenverhalten wobei sich die Eigenschaften der geladenen und entladenen Phase mitunter stark voneinander unterscheiden. Die wesentlichen Unterschiede zeigen sich hierbei in der ionischen und elektronischen Leitfähigkeit. Die Eigenschaften der beiden Phasen werden in dieser Arbeit anhand der Impedanzspektren des Batteriesystems gezeigt und es werden Rückschlüsse über die Phasenumwandlung des Systems aus diesen Daten gezogen. Dabei wird vor allem diskutiert, ob es sich wirklich um einen Zweiphasenübergang oder eher um einen Übergang über eine feste Lösung handelt. Neben der Phasenumwandlung des System werden auch weitere Eigenschaften des Systems insbesondere in der Wechselwirkung des Elektrodenmaterials mit dem Elektrolyten und dem Substratmaterial erläutert. Dabei zeigte sich vor allem, dass der Widerstand zwischen Elektrode und Elektrolyt vernachlässigbar ist, jedoch je nach verwendetem Substratmaterial der elektronische Übergang gestört werden kann. Dies liegt in der halbleitenden bis isolierenden Natur des Lithiumtitanates begründet, was im Kontakt zu halbleitenden Materialien zu störenden Raumladungszonen innerhalb des Materials führt. Diese Raumladungszonen liegen auch im Kontakt mit Metallen vor und können bei sehr dünnen Schichten das Zellverhalten stören. Im zweiten Teil der Arbeit werden ähnliche Untersuchungen an einem zweiten Elektrodenmaterial, dem Lithium-Nickel-Manganoxid durchgeführt. Dieses Material ist aufgrund seiner hohen Arbeitsspannung als Kathodenmaterial interessant. Die Untersuchungen beschäftigen sich dabei im Wesentlichen mit den Problemen bei der Herstellung und Hafteigenschaften des Systems und mit der Beurteilung des Verhaltens an den Grenzfläche. Hierbei wird vor allem der Vergleich zum Lithiumtitanatsystem betrachtet und Gemeinsamkeiten sowie Unterschiede diskutiert. Zudem beschäftigt sich die Arbeit mit der Frage welche Phase des Materials abgeschieden wird und wie sich die Grenzfläche zwischen Kathode und Festelektrolyt in Abhängigkeit des Herstellungsprozesses verhält

From Jet Counting to Jet Vetoes

The properties of multi-jet events impact many LHC analysis. The exclusive number of jets at hadron colliders can be described in terms of two simple patterns: staircase scaling and Poisson scaling. In photon plus jets production we can interpolate between the two patterns using simple kinematic cuts. The associated theoretical errors are well under control. Understanding such exclusive jet multiplicities significantly impacts Higgs searches and searches for supersymmetry at the LHC.Comment: 4 pages, 4 figures, to appear in the proceedings of XX International Workshop on Deep-Inelastic Scattering and Related Subjects, 26th-30th March 2012, University of Bon

Effectiveness of an Observation Unit and Transition Team on Length of Stay: Before and After Study

There have been many proposed solutions to decrease emergency department (ED) overcrowding and increase the quality of care in this particular population. However, there is little research suggesting the use of combining short-term observational units, as well as transition teams, in order to reduce ED length of stay (LOS) in patients awaiting disposition or inpatient bed assignments. The purpose of this study is to explore the effect of using short-term observational units and transition teams in order to decrease length of stay in patients originating from the emergency department who are awaiting disposition or inpatient bed assignments