Halogenated Polycyclic Aromatic Hydrocarbons (X-PAHs) are ubiquitous contaminants that are thought to be generated by processes such as chemical industries and incomplete combustion, including waste incineration and electronic waste (e-waste) burning. X-PAHs are a concern for environmental and human health because they are toxic, mutagenic, and are expected to be more lipophilic than the parent compounds. To study these compounds in the environment, an analytical method was developed, utilizing large-volume injection via a programmable temperature vaporizing (PTV) inlet, using environmental samples from an e-waste area and in Guangzhou, China. The concentrations of 26 X-PAHs were measured in atmospheric particulate matter (PM), house dust (HD), and sediment. In general, the X-PAH concentrations in PM were low, with concentrations ranging from <0.078 to 41.81 pg/m³. There was no significant difference in X-PAH concentrations in PM between the e-waste area and Guangzhou. These concentrations are of the same order of magnitude as previous studies of X-PAHs in PM. These data suggest that e-waste activities are not a significant source of X-PAHs in atmospheric PM. The concentrations of X-PAHs in HD samples ranged from <0.0372 to 3575 pg/g dry weight. In general, there was no significant difference between E-waste and Guangzhou HD concentrations. The profiles of X-PAHs in PM and HD were different, suggesting that there are additional sources for X-PAHs inside homes other than outdoor air. The concentrations of X-PAHs in sediment samples from an e-waste site ranged from <104 to 2890 pg/g dry weight. The X-PAH profile in sediment more closely resembled the X-PAH profile of PM. / Graduation date: 2011

Une turbulence inhomogène est étudiée expérimentalement dans un contexte lagrangien. La mesure des trajectoires de traceurs lagrangiens et de particules inertielles a été effectuée dans un canal plan turbulent et a été utilisée pour obtenir des statistiques lagrangiennes conditionnées à leur distance initiale par rapport à la paroi. Ces mesures à haute résolution en temps et en espace fournissent les trois composantes de la position, la vitesse et l'accélération le long de la trajectoire d'une particule individuelle depuis des distances très proches de la paroi (~10 unités de paroi) jusqu'au centre du canal. Les corrélations temporelles lagrangiennes ont permis la mesure directe des échelles de temps de la vitesse et l'accélération dans chacune des trois directions. Ces échelles caractérisent l'inhomogénéité et l'anisotropie du canal turbulent dans une perspective lagrangienne. Une anisotropie à petite échelle, quantifiée par la "skewness", et les corrélations entre composantes de l'accélération sont observées dans tout le canal. Une séparation d'échelle significative entre les composantes de l'accélération et son amplitude a été mesurée au travers du canal notamment dans la zone proche de la paroi. Deux classes de particules inertielles ont été étudiées permettant ainsi la comparaison directe entre statistiques des traceurs et des non-traceurs dans la zone de fort cisaillement et de forte anisotropie proche de la paroi jusqu'à la région plus homogène du centre. Les propriétés statistiques des particules inertielles dans le canal turbulent sont significativement différentes de celles observées en turbulence homogène isotrope. Ces statistiques sont les ingrédients nécessaires à la construction de modèles stochastiques lagrangiens pour la prédiction de la dispersion et du mélange en turbulence inhomogène. / Inhomogeneous turbulence is experimentally investigated in a Lagrangian framework. Measurements of tracer and non-tracer particles in a turbulent channel were made, and were used to extract Lagrangian statistics conditioned on their initial distance to the channel wall. Highly resolved in time and space, these measurements provide the three components of position, velocity, and acceleration along a particle trajectory from very close to the channel wall ($y^+approx 10$) to the channel center. Lagrangian time correlations allow the direct measurement of velocity and acceleration timescales in each direction, and characterize the inhomogeneity and anisotropy of the turbulent channel from the Lagrangian perspective. Small scale-anisotropy, characterized by the skewness and the correlation of the components of the acceleration, was found to be significant throughout the channel. Significant scale separation between the magnitude and components of acceleration was found across the channel, even in the near-wall region. Two classes of non-tracer particle trajectories were also measured, allowing direct comparison of tracer and non-tracer statistics from the highly-sheared anisotropic zone near the channel wall to the more homogeneous outer layer. Non-tracer acceleration statistics in the turbulent channel were found to be significantly different from similar results in homogeneous, isotropic turbulence. These statistics are necessary components of advanced Lagrangian stochastic models to predict dispersion and mixing in inhomogeneous turbulence.

The purpose of this study was to estimate the CTV-PTV margin required for prostate and head and neck cancer treatments at the radiotherapy departments of Karolinska University Hospital.    Portal image data from patients treated at the radiotherapy departments during the period of 2009-2011 was used to estimate the set-up displacements for each treatment area. By using the acquired images the magnitude of the systematic, i.e. preparatory, and random, i.e. execution, error was determined in the anterior-posterior (AP), superior-inferior (SI) and right-left (RL) direction. The calculated PTV margin is based on the systematic and random errors of the entire patient populations. A total of 40 patients were used for the analysis of prostate treatments and 47 patients for head and neck treatments. The evaluation of the PTV margin was done for three different matching protocols; no matching (skin marker alignment), five day matching and daily matching.      With no image verification in prostate treatments the calculated PTV margin taking both inter- and intrafractional errors into account was 13.6, 9.2 and 7.9 mm in AP, SI, and RL direction respectively. The corresponding PTV margin in head and neck treatments was found to be 6.7, 5.3 and 4.9 mm. Using a five day matching protocol of the bony anatomy showed no considerable reductions in margins for neither prostate nor head and neck treatments. With daily matching of the bony anatomy in prostate treatments the calculated margins was reduced to 8.1, 7.9 and 2.4 mm in the AP, SI and RL direction respectively.  Measurements of the residual deviations of individual cervical vertebrae after daily image verification and correction in head and neck cancer treatments showed that all matching protocols will require larger margins in the lower vertebrae in order to account for the set-up error in the AP direction. The corresponding margins needed using daily matching of the bony anatomy would be 3.9, 5.4 and 6.0 mm for C1, C4 and C5 respectively in the AP direction.    In the absence of daily imaging the currently used PTV margins might be inadequate for covering to movement of the targets. The deviations in the AP direction of the cervical vertebrae in head and neck cancer treatments should be investigated further in order to ensure that the motion of the target is covered and that no risk organs are subjected to harmful dose levels.

No description available.

This work focuses on both high fidelity experimental and numerical thermal hydraulic studies and advanced frequency decomposition methods. The major contribution of this work is a proposed method for spatio-temporal decomposition of frequencies present in the flow. This method provides an instantaneous visualization of coherent frequency ?structures? in the flow. The significance of this technique from an engineering standpoint is the ease of implementation and the importance of such a tool for design engineers. To validate this method, synthetic verification data, experimental data sets, and numerical results are used. The first experimental work involves flow through the side entry orifice (SEO) of a boiling water reactor (BWR) using non-intrusive particle tracking velocimetry (PTV) techniques. The second experiment is of a simulated double ended guillotine break in the prismatic block gas cooled reactor. Numerical simulations of jet flow mixing in the lower plenum of a prismatic block high temperature gas cooled reactor is used as a final data set for verification purposes as well as demonstration of the applicability of the method for an actual computational fluid dynamics validation case.

In a pressurized water reactor (PWR), pressurized water flows over fuel rods containing radioactive uranium. Potential failure of these nuclear fuel rods is a primary concern, as fuel rod failure typically results in power generation losses and reactor downtime. Thermal parameters such as critical heat flux have traditionally been utilized as performance metrics to ensure that the reactor core remains stable even during failure events. Recently, fuel leaking events have occurred which have resulted in excess debris buildup on fuel rods and fuel grid array mixing devices. Understanding the flow field surrounding these nuclear fuel rods is critical in predicting where crud could deposit. Although CFD simulations have been conducted to characterize the fluid flow around fuel rod bundles, limited experimental data characterizing the mechanics of this fluid flow exists in the current literature. This study will present experimental data collected detailing the fluid flow around a rod bundle geometry using a novel matched refractive index particle tracking velocimetry (PTV) technique over a 3D volume cross section of a prototypical nuclear fuel rod bundle. Velocimetry tracking will be performed in order to characterize the mechanics of the fluid flow. Using optical distortion mitigation techniques and various image processing methods, data from multiple cameras was used to assemble 3-dimensional velocity information of a turbulent fluid region. Results are compared to the solution of a k-epsilon unsteady RANS numerical simulation.

A particle tracking velocimetry (PTV) system is used to investigate the turbulent properties at the free surface of shallow shear flows and a shallow vortex street (VS) wake flow. The resolution of the PTV system enables information to be gathered regarding the large-scale turbulent structure of these flows, and also enables analysis to proceed in both the temporal and spatial domains. Statistical tools such as the probability density function (PDF), autocorrelation and power spectral density (PSD) are utilised to characterise the turbulent properties at the flow surface. Two supercritical flows and one subcritical shallow shear flow are analysed. Taylor's frozen turbulence hypothesis is shown to be valid for these flows, and the integral length scales indicate that 2D isotropic structures with scales larger than the flow depth are present at the free surface. Such large-scale structures at the free surface are consistent with observations from dye visualisation experiments and with "spiral eddies" identified by Kumar, et al (1998). The longitudinal extent of near and intermediate wake fields for the shallow VS wake flow is well defined by the integral wake length scale specified by v.Carmer (2005). The near wake region is characterised by high rates of exchange between the mean flow and large-scale 2D coherent structures (2DCS). In the intermediate field, the rate of decay of the turbulent stress components greatly diminishes as the 2DCS are stabilised and dissipated under the action of bed friction. Multiple peaks are observed in the power spectral density of the turbulent fluctuations. The periodic shedding of 2DCS behind the circular cylinder is characterised by an energy peak at a Strouhal number of 0.21, and further energy peaks are observed in the near-wake region. The PSD estimates are consistent with the findings of v.Carmer (2005) in which a -5/3 decay law to high frequencies is observed, and no evidence of an inverse energy cascade is present.

Linköpings kommun har i senaste trafikstrategin från 2010 antagit målet att år 2030 ska var femte resa i kommunen ske med kollektivtrafik. För att nå målet behöver kollektivtrafikens attraktionskraft öka. För att ta fram exempel på hur detta kan göras genomfördes examensarbetet med syftet att ”analysera hur korsningen mellan Brokindsleden och Söderleden i Linköping kan förändras för att minska fördröjningen för kollektivtrafik år 2030”. Analysen genomfördes med hjälp av mikrosimuleringsprogrammet PTV Vissim. I en simuleringsstudie jämfördes fyra olika scenarier. NU0 och NU1 som beskriver nuläget utan och med kollektivtrafiksprioritet. Jämförelsealternativet, JA, bygger på en trafikprognos för 2030 och i utredningsalternativet, UA, förändras JA för att minska kollektivtrafikens fördröjning. Den kollektivtrafiksprioritering som används idag beräknades i genomsnitt minska fördröjningen med fem procent per buss motsvarande tre sekunder. Denna minskning är dock inte signifikant. Om korsningen inte förändras till 2030 beräknades fördröjningen för kollektivtrafiken öka med 87 procent. Den övriga trafiken kommer att få en ökning med 45 procent. Utifrån dessa resultat gjordes flera förändringar i simuleringsmodellen, bland annat infördes prioritet för alla bussar och kollektivtrafikskörfält på Brokindsleden. Med förändringarna minskade fördröjningen för buss med 78 procent. Den övriga trafiken påverkas också positivt med en minskning på elva procent, nästan tio sekunder per fordon. Utifrån detta drogs slutsatsen att en förändring med de förslagna åtgärderna mycket väl kan vara alla trafikanter till nytta.

Over the last 30 years, Particle Image Velocimetry (PIV) has become the most powerful tool to study velocity fields in fluid mechanics. This technique is non-intrusive requiring seeding the flow with small tracer particles. The hardware required for these sophisticated PIV methods is very expensive (CCD or CMOS high-speed cameras and lasers), and the present dissertation aims to develop novel and inexpensive alternatives. The first part of this work investigates the use of multiple smartphones as a lower-cost Tomographic-PIV system for reconstructing 3D-3C velocity fields. We use colored shadows to imprint two or three different time-steps on the same image in a RGB-backlit configuration. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction, and particle-field correlations, to obtain three velocity components in a volume. The proposed system is tested with a vortex ring and the results are compared to stereoscopic-PIV for error estimations. We expand this work to a high-speed time-resolved setup to obtain 3D-3C velocity fields in time. This improvement is possible using newer smartphones capable of recording high-speed video at HD resolution. The challenges of using such cameras are presented and tackled. The illumination system, testing flow and image processing is similar to the one presented in the first section. A benchmark of the smartphone system is carried out comparing it to a Tomo-PIV system capable of recording 4K video resolution. A different approach is proposed to reconstruct a 3D-3C velocity field using a single color video camera. This technique uses chromatic structured light with color-gradients projected perpendicularly with respect to the color camera. Thus, we encode the depth position of the particles with a different wavelength of light. Different light sources are used to produce such color gradients. Finally, a variation of the previous technique is tested using a single monochromatic camera and structured volumetric illumination with spatially varying intensity profiles. This technique enables us to encode the depth position of every particle in their intrinsic brightness. The proposed system can achieve a depth resolution of 200 levels, i.e., an order of magnitude higher than previously proposed systems.

No description available.