Three-dimensional flow patterns at a river difluence on the alluvial system of the Paraná River, Argentina

Water Qualit

Geodesy: The science underneath

Geodesy is the science of precisely measuring and mapping the Earth’s surface and locations of objects on it, the figure of the Earth and her gravity field, and changes in all these over time. Geodesy is an old science, going back to the days when land was taken into agricultural use and needed to be mapped. It is also a modern science, serving vital infrastructure needs of our developing global technological society. This text aims to describe the foundations of both traditional geodesy, mapping the Earth within the constraints of the human living space, and modern geodesy, exploiting space technology for mapping and monitoring our planet as a whole, in a unified threedimensional fashion. The approach is throughout at conveying an understanding of the concepts, of both the science and mathematics of measuring and mapping the Earth and the technologies used for doing so. The history of the science is not neglected, and the perspective of the presentation is unapologetically Finnish.Geodesia on tiede, joka mittaa ja kartoittaa tarkasti Maan pintaa ja sen päällä olevia kohteita, Maan muotoa ja painovoimakenttää, sekä niiden kaikkien ajallisia muutoksia. Geodesia on vanha tiede, joka oli olemassa jo muinoin kun maanviljely alkoi ja peltoja piti kartoittaa. Se on myös moderni tiede, joka palvelee modernin, kehittyvän globaalin teknologisen yhteiskuntamme olennaisia infrastruktuuritarpeita. Tämä kirja esittää sekä perinteisen että modernin geodesian perusteet. Perinteinen geodesia kartoittaa Maata ihmisen elintilan puitteissa ja sen ehdolla, kun moderni geodesia käyttää avaruusteknologiaa koko maaplaneetamme kartoittamiseksi ja seuraamiseksi yhtenäisellä kolmiulotteisella tavalla. Tavoitteena on auttaa Maan mittaamiseen ja kartoittamiseen liittyvien sekä tieteellis-matemaattisten että teknologisten käsitteiden ymmärtämistä. Geodesian historiaa ei unohdeta, ja kirjoitelman näkökulma on avoimesti suomalainen

Validation and verification of the Atmospheric Radionuclide Transport Model (ARTM)

Aufgrund der Tatsache, dass die Immissionen radioaktiver Nuklide, resultierend aus den Freisetzungen kerntechnischer Anlagen in Deutschland, im Vergleich zum natürlich vorkommenden radioaktiven Untergrund zu gering sind, um effizient in der Umgebung der Anlagen gemessen werden zu können, ist das Bundesamt für Strahlenschutz (BfS) zum Schutz der Bevölkerung dazu angehalten, deren Ausbreitung zu simulieren und die maximale Personendosis zu berechnen. Während seit den 1970er Jahren Gauß-Fahnenmodelle in Gebrauch waren, hat die Entwicklung immer neuerer und schnellerer Rechenmaschinen Anreize zur Entwicklung des realistischeren Lagrange-Teilchenmodell gesetzt, welche in naher Zukunft für behördliche Zwecke zur Bewertung der Strahlenexposition durch radioaktive Emissionen zum Einsatz kommen sollen. Eines dieser Lagrange-Teilchenmodelle – entwickelt für Langzeitausbreitungen – ist das Atmosphärische-Radionuklid-Transport-Modell (ARTM). In dieser Arbeit wird ARTM anhand realer und fiktiver Szenarien, in welchen das Programmverhalten und seine Simulationsergebnisse untersucht werden, verifiziert und validiert. Eine intensive Sensitivitätsanalyse einiger ausgewählter Modelleingabeparameter und deren Auswirkung auf die Ergebnisse wurde durchgeführt, um die programminternen mathematischen Algorithmen zu verifizieren. ARTM wurde auch zur Validierung und zur Evaluierung der Simulationsergebnisse auf zwei Szenarien angewendet, bei denen Immissionsmessdaten vorhanden waren. Diese Untersuchungen – zuzüglich eines Vergleichs mit dem Kurzzeitausbreitungsmodell LASAIR (Lagrange-Simulation der Ausbreitung und Inhalation von Radionukliden) – zeigen den Anwendungsbereich von ARTM auf und wo noch weitere Entwicklungen nötig sind.Due to the fact that the immissions resulting from the release of radioactive nuclides from nuclear facilities in Germany are too small in comparison to the natural radioactive background to be efficiently measured in their vicinity, the German Federal Office for Radiation Protection (BfS) is obliged to simulate their distribution and calculate the maximum dose rates in order to protect the population. While since the 1970’s Gaussian plume models have been in use, the advent of fast modern computing machines has triggered the development towards the more realistic Lagrangian particle models which shall be used for regulatory purposes in order to assess the radiation exposure from radioactive emissions in the near future. One of these Lagrangian models, developed for simulating long-term emissions, is the Atmospheric Radionuclide Transport Model (ARTM). In this work, ARTM is verified and validated for several real and fictive scenarios, in which both the behaviour of the programme and its simulation results are studied. An intensive sensitivity study on a selection of model input parameters and their effect on results is performed in order to verify the programme-internal mathematical algorithms. ARTM is also applied to two scenarios where measurement data were available in order to validate and evaluate the simulation results. These studies, plus a comparison with the short-term model LASAIR (Lagrange Simulation of Dispersion and Inhalation of Radionuclides), demonstrate the range of usability for ARTM and where further development is needed

Studying Quantum-state Resolved Molecule Surface Collisions

The interaction between molecular hydrogen and a surface is of vital importance to many areas of scientific research. Thus, understanding this interaction and being able to model it is very beneficial. The goal of this master’s thesis is to characterise the interaction of hydrogen scattering from a hydrogen passivated chromium(110) surface. The thesis will describe the surface scattering measurements as well as the techniques previously developed to allow for these measurements. The quantum mechanical state of the molecular hydrogen is coherently controlled both before and after the scattering with the surface to theoretically allow for extraction of the scattering matrix from this data, which completely describes the interaction. Scattering both under specular and diffraction channel conditions were described, with the scattering at specular conditions demonstrating that the surface appears as a mirror to the hydrogen under these conditions. However, due to the noise encountered when measuring the signal when scattered into the (0,1) diffraction channel, the results for the scattering matrix for this this measurement are not entirely conclusive. This thesis will demonstrate that the measured signals are still able to provide a benchmark for theoreticians modelling the interaction. We then explore the various possible results for the scattering matrix and the conclusions we can draw from these, such as the high probability that hydrogen molecules rotating as helicopters relative to the surface ( = ±1) are more likely to scatter into the (0,1) diffraction channel than those rotating as cartwheels ( = 0). A possible resolution to these variety of results is just examining the best fit result to the experimental data; this thesis will describe this result and also explore the extent to which this result can be regarded over other possible solutions. Finally various data treatment options such as frequency filtering will be investigated in attempt to clarify the results from our experimental data

Optically Induced Nanostructures

Nanostructuring of materials is a task at the heart of many modern disciplines in mechanical engineering, as well as optics, electronics, and the life sciences. This book includes an introduction to the relevant nonlinear optical processes associated with very short laser pulses for the generation of structures far below the classical optical diffraction limit of about 200 nanometers as well as coverage of state-of-the-art technical and biomedical applications. These applications include silicon and glass wafer processing, production of nanowires, laser transfection and cell reprogramming, optical cleaning, surface treatments of implants, nanowires, 3D nanoprinting, STED lithography, friction modification, and integrated optics. The book highlights also the use of modern femtosecond laser microscopes and nanoscopes as novel nanoprocessing tools

Enrichment of a 3D building model with windows using oblique-view ALS and façade textures

A wide range of applications using 3D building models exists; such as computer games, city marketing, disaster management, tourist information systems, simulations of noise propagation and surveillance of sustainable construction. Complete acquisition of large urban scenes has become feasible using multi-aspect-oblique-view ALS; however, automated generation of detailed 3D models, the main focus of this thesis, still poses a significant challenge. \ud \ud To enable enrichment of a 3D building model with windows, the 3D wire-frame building model and the ALS point cloud are first automatically co-registered. The novel approach to window extraction presented in this thesis exploits evidences about window positions in processed oblique-view ALS point cloud and façade image textures. Laser beam penetrates glassy window areas, and thus points found behind a segmented façade plane, projected onto the façade plane, give reliable evidence about intrusion positions. On the other hand, high values of gradient on a texture are usually due to window frames. These two facts are exploited when extracting initial window patches. Additionally, binary masks, obtained by region growing of homogeneous parts of façade textures, are used to eliminate certain façade artefacts and to improve shape of window patches. The assumption, that many windows of the same kind are on the same floor, is used for the refinement procedure. First, façade textures are divided into horizontal blocks, representing floors. Second, a search for non-similar window patch templates within each block is performed. Third, to obtain additional window patch positions, the chosen templates are cross-correlated along the respective block. \ud \ud Eleven façade planes of an existing 3D wire-frame building model are textured with extracted patches, representing windows and other intrusions. Despite different arrangements of windows, varying window sizes, and relatively strict evaluation method, the method results in 63% detection rate. What is more, the method is mostly data-driven and the detection rate outperforms the method using only oblique-view ALS (Tuttas & Stilla, 2013). The windows are well defined, since the basis for most of window patches are connected components of edges belonging to window frames

Cartography

The terrestrial space is the place of interaction of natural and social systems. The cartography is an essential tool to understand the complexity of these systems, their interaction and evolution. This brings the cartography to an important place in the modern world. The book presents several contributions at different areas and activities showing the importance of the cartography to the perception and organization of the territory. Learning with the past or understanding the present the use of cartography is presented as a way of looking to almost all themes of the knowledge

Asymptotic-Preserving methods and multiscale models for plasma physics

The purpose of the present paper is to provide an overview of As ymptotic- Preserving methods for multiscale plasma simulations by ad dressing three sin- gular perturbation problems. First, the quasi-neutral lim it of fluid and kinetic models is investigated in the framework of non magnetized as well as magne- tized plasmas. Second, the drift limit for fluid description s of thermal plasmas under large magnetic fields is addressed. Finally efficient nu merical resolutions of anisotropic elliptic or diffusion equations arising in ma gnetized plasma simu- lation are reviewed