Sharp Estimates for Oscillatory Integral Operators via Polynomial Partitioning

The sharp range of $L^p$-estimates for the class of H\"ormander-type oscillatory integral operators is established in all dimensions under a positive-definite assumption on the phase. This is achieved by generalising a recent approach of the first author for studying the Fourier extension operator, which utilises polynomial partitioning arguments.Comment: Updated version incorporating minor corrections, additional clarification and an expanded discussion of applications. 95 pages. 6 figures. To appear Acta. Mat

The influence of phase angle, strain range and peak cycle temperature on the TMF crack initiation behaviour and damage mechanisms of the nickel-based superalloy, RR1000

Thermo-mechanical fatigue (TMF) tests including 0°, 90°, -90°, 45° -135° and -180°, phasing (φ) between mechanical loading and temperature were undertaken on a polycrystalline nickel-based superalloy, RR1000. Mechanical loading was employed through strain control whilst 300-700 °C and 300-750°C thermal cycles were achieved with induction heating and forced air cooling. Mechanical strain ranges from 0.7 to 1.4% were employed. Results show that, for the strain ranges tested, TMF life is significantly affected by the employed phase angle. Furthermore the strain range and peak cycle temperature used has a substantial influence on the significance of dominant damage mechanisms, and resultant life. Various metallographic examination techniques have outlined that the dominant damage mechanisms are creep deformation at higher temperatures and early cracking of oxide layers at lower temperatures

Arachidonic acid pathway alterations in cerebrospinal fluid of dogs with naturally occurring spinal cord injury

BACKGROUND: Canine intervertebral disc πherniation causes a naturally-occurring spinal cord injury (SCI) that bears critical similarities to human SCI with respect to both injury pathomechanisms and treatment. As such, it has tremendous potential to enhance our understanding of injury biology and the preclinical evaluation of novel therapies. Currently, there is limited understanding of the role of arachidonic acid metabolites in canine SCI. RESULTS: The CSF concentrations of PLA2 and PGE2 were higher in SCI dogs compared to control dogs (p = 0.0370 and 0.0273, respectively), but CSF LCT4 concentration in SCI dogs was significantly lower than that in control dogs (p < 0.0001). Prostaglandin E2 concentration in the CSF was significantly and positively associated with increased severity of SCI at the time of sampling (p = 0.041) and recovery 42 days post-injury (p = 0.006), as measured by ordinal behavioral scores. CONCLUSION: Arachidonic acid metabolism is altered in dogs with SCI, and these data suggest that these AA metabolites reflect injury severity and recovery, paralleling data from other model systems

Modeling aerosols using the chemistry transport model MOCAGE : application to the air quality in the Mediterranean basin

L'objectif de cette thèse est de réaliser un bilan des aérosols atmosphériques sur le bassin méditerranéen et de caractériser la qualité de l'air de cette région en se focalisant sur des indicateurs d'exposition à long terme. Basés sur des simulations du modèle de chimie-transport MOCAGE, (MOdèle de Chimie Atmosphérique à Grande Échelle), les travaux portent dans un premier temps sur le développement d'un module permettant de prendre en compte les aérosols inorganiques secondaires. Ce module a été validé à différentes échelles et avec différents types de données. Le modèle MOCAGE a ensuite servi à simuler la composition chimique de l'atmosphère sur le bassin méditerranéen pour l'année 2013. Nous avons ainsi pu montrer que le bassin méditerranéen est une région exportatrice d'aérosols. Nous avons également étudié l'impact des émissions anthropiques maritimes et côtières sur le bilan des aérosols et la qualité de l'air dans la région méditerranéenne.The objective of this thesis are to establish a budget of the atmospheric aerosols on the Mediterranean basin and to characterize air quality over this region based on long term exposition indicators. Based on simulations made with the chemical transport model MOCAGE (Modèle de Chimie Atmosphérique à Grande Échelle), the first part of this work is devoted to the development of a secondary inorganic aerosols module. This module was validated at different scales using a large variety of types of data. The MOCAGE model has then been used to simulate the chemical composition on the Mediterranean basin over the year 2013. We were able to show that the Mediterranean area is an export zone for aerosols. We also studied the impact of marine and coastal anthropogenic emissions on the aerosol budget and the air quality in the basin

Modélisation des aérosols à l'aide du modèle de chimie transport MOCAGE : application à la qualité de l'air dans le bassin méditerranéen

The objective of this thesis are to establish a budget of the atmospheric aerosols on the Mediterranean basin and to characterize air quality over this region based on long term exposition indicators. Based on simulations made with the chemical transport model MOCAGE (Modèle de Chimie Atmosphérique à Grande Échelle), the first part of this work is devoted to the development of a secondary inorganic aerosols module. This module was validated at different scales using a large variety of types of data. The MOCAGE model has then been used to simulate the chemical composition on the Mediterranean basin over the year 2013. We were able to show that the Mediterranean area is an export zone for aerosols. We also studied the impact of marine and coastal anthropogenic emissions on the aerosol budget and the air quality in the basin.L'objectif de cette thèse est de réaliser un bilan des aérosols atmosphériques sur le bassin méditerranéen et de caractériser la qualité de l'air de cette région en se focalisant sur des indicateurs d'exposition à long terme. Basés sur des simulations du modèle de chimie-transport MOCAGE, (MOdèle de Chimie Atmosphérique à Grande Échelle), les travaux portent dans un premier temps sur le développement d'un module permettant de prendre en compte les aérosols inorganiques secondaires. Ce module a été validé à différentes échelles et avec différents types de données. Le modèle MOCAGE a ensuite servi à simuler la composition chimique de l'atmosphère sur le bassin méditerranéen pour l'année 2013. Nous avons ainsi pu montrer que le bassin méditerranéen est une région exportatrice d'aérosols. Nous avons également étudié l'impact des émissions anthropiques maritimes et côtières sur le bilan des aérosols et la qualité de l'air dans la région méditerranéenne

First implementation of secondary inorganic aerosols in the MOCAGE version R2.15.0 chemistry transport model

In this study we develop a secondary inorganic aerosol (SIA) module for the MOCAGE chemistry transport model developed at CNRM. The aim is to have a module suitable for running at different model resolutions and for operational applications with reasonable computing times. Based on the ISORROPIA II thermodynamic equilibrium module, the new version of the model is presented and evaluated at both the global and regional scales. The results show high concentrations of secondary inorganic aerosols in the most polluted regions: Europe, Asia and the eastern part of North America. Asia shows higher sulfate concentrations than other regions thanks to emission reductions in Europe and North America. Using two simulations, one with and the other without secondary inorganic aerosol formation, the global model outputs are compared to previous studies, to MODIS AOD retrievals, and also to in situ measurements from the HTAP database. The model shows a better agreement with MODIS AOD retrievals in all geographical regions after introducing the new SIA scheme. It also provides a good statistical agreement with in situ measurements of secondary inorganic aerosol composition: sulfate, nitrate and ammonium. In addition, the simulation with SIA generally gives a better agreement with observations for secondary inorganic aerosol precursors (nitric acid, sulfur dioxide, ammonia), in particular with a reduction of the modified normalized mean bias (MNMB). At the regional scale, over Europe, the model simulation with SIA is compared to the in situ measurements from the EMEP database and shows a good agreement with secondary inorganic aerosol composition. The results at the regional scale are consistent with those obtained from the global simulations. The AIRBASE database was used to compare the model to regulated air quality pollutants: particulate matter, ozone and nitrogen dioxide concentrations. Introduction of the SIA in MOCAGE provides a reduction in the PM2.5 MNMB of 0.44 on a yearly basis and up to 0.52 for the 3 spring months (March, April, May) when SIAs are at their maximum