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"Die Technische Universitat Berlin und die teleskopie GmbH - ein mit der telemetrischen
Fernsehzuschauerforschung befaßtes Institut der Infas-Gruppe - haben eine Kooperationsvereinbanuig
getroffen mit dem Ziel, die Daten der teleskopie auch der Medienwissenschaft zugänglich zu machen. Der folgende Beitrag beschreibt das Fernsehzuschauerpanel, die in den Panel-Haushalten eingesetzte Meßtechnik, die Datenbank der teleskopie sowie Nutzungsmodalitäten für den Bezug telemetrischer Daten." (Autorenreferat)

Eine multivariate Varianzanalyse von Erhebungsdaten der Allgemeinen Bevölkerungsumfrage der Sozialwissenschaften (ALLBUS), die von Gehring und Böltken durchgeführt wurde, ergab, daß die Ausländerfeindlichkeit abgenommen hat. Der Autor zeigt in seinem Beitrag, daß eine Anwendungsvoraussetzung der multivariaten Varianzanalyse nicht gegeben war: die Varianzen und Kovarianzen der vier abhängigen Variablen haben 1984 signifikant andere Werte als 1980. Im folgenden wird dann ein alternativer statistischer Test vorgestellt, der auch bei Inhomogenität der Varianzen und Kovarianzen zwischen den Gruppen Mittelwertsvergleiche erlaubt. Dieser LISREL-Test erweist sich als eine leicht anzuwendende Alternative zur klassischen multivariaten Varianzanalyse. (NG)

"Mit diesem Beitrag soll ein Kommentar zu Patrick O'Briens Vorschlag geliefert werden, in einem kooperativen Forschungsvorhaben die wirtschaftliche Leistung westeuropäischer Länder zu messen. Die Arbeit gliedert sich in drei Teile: a) zunächst werden die Ergebnisse meiner kürzlich fertiggestellten Studie über die langfristigen Änderungen des Pro-Kopf-Einkommens und der Produktivität in sechzehn fortgeschritten kapitalistischen Ländern zusammengefaßt; b) sodann werden Wirtschaftshistorikern, die weitere Forschung auf diesem Gebiet betreiben, einige Vorschläge gemacht. Vor allem wird dabei betont, wie sinnvoll es ist, makroökonomische Messungen auf ziemlich hohem Aggregationsniveau selbst für die Zeiträume durchzuführen, die wegen ihrer zeitlichen Distanz dieser Methode nicht zugänglich sein sollen; c) in einem Anhang sind langfristige Schätzungen des Bruttoinlandsproduktes (Gross Domestic Product) von sechzehn Ländern aufgeführt. Die Quellenhinweise dazu belegen, wie reichhaltig schon jetzt Material über die Messung wirtschaftlicher Leistung auf makroökonomischer Ebene zur Verfügung steht." (Autorenreferat)

International audience A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as "Release of an acute toxic gas": waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, 2014b). When the substances with the cited hazard statement codes react with water or an acid, they can release HCl, Cl2, HF, HCN, PH3, H2S, SO2 (and two other gases very unlikely to be emitted, hydrazoic acid HN3 and selenium oxide SeO2 – a solid with low vapor pressure). Hence, a method is proposed : -1. Measurement of the volume of gases emitted into contact with water or an acid (solid/liquid ratio of 10 L water or acid/kg raw waste, acid 2.5 M HNO3). -2. If gas is emitted at a rate higher than 0.1 L of gas/kg waste in 5 min (limit of quantification of the automated calcimètre used here), checking if one of the cited gases is emitted with electrochemical detection probes or simple qualitative colorimetric methods. -3. If one of these gases is detected, speciation of the emitting substance(s) (calculation by the "worst case" method from elements concentrations, or by specific analytic methods) and checking whether they have a hazard statement code EUH029, EUH031 or EUH032 (a list is provided). For a set of 49 waste, water addition did not produce gas. Nearly all the solid waste produced a gas in contact with hydrochloric acid in 5 min in an automated calcimeter with a volume >0.1 L of gas per kg of waste. Since a plateau of pressure is reached only for half of the samples in 5 min, 6 h trial with calorimetric bombs or glass flasks were done and confirmed the results. Identification of the gases by portable probes showed that most of the tested samples emit mainly CO2. Toxic gases are emitted by four waste: metallic dust ...

1. Introduction -- 1.1 Preamble -- 1.2 Scope of book -- 1.3 Notation and definitions -- 2. Pipe and Channel Flow -- 2.1 Introduction -- 2.2 Laminar flow theory: channel -- 2.3 Laminar flow theory: pipe -- 2.4 The Reynolds number -- 2.5 The entry length -- 2.6 Transition to turbulent flow -- 2.7 Relationship between flow rate and pressure gradient -- 3. Flow Past a Circular Cylinder -- 3.1 Introduction -- 3.2 The Reynolds number -- 3.3 Flow patterns -- 3.4 Drag -- 4. Convection in Horizontal Layers -- 4.1 The configuration -- 4.2 Onset of motion -- 4.3 Flow regimes -- 5. Equations of Motion -- 5.1 Introduction -- 5.2 Fluid particles and continuum mechanics -- 5.3 Eulerian and Langrangian co-ordinates -- 5.4 Continuity equation -- 5.5 The substantive derivative -- 5.6 The Navier—Stokes equation -- 5.7 Boundary conditions -- 5.8 Condition for incompressibility -- Appendix: Derivation of viscous term of dynamical equation -- 6. Further Basic Ideas -- 6.1 Streamlines, streamtubes, particle paths and streaklines -- 6.2 Computations for flow past a circular cylinder -- 6.3 The stream function -- 6.4 Vorticity -- 6.5 Vorticity equation -- 6.6 Circulation -- 7. Dynamical Similarity -- 7.1 Introduction -- 7.2 Condition for dynamical similarity: Reynolds number -- 7.3 Dependent quantities -- 7.4 Other governing non-dimensional parameters -- 8. Low and High Reynolds Numbers -- 8.1 Physical significance of the Reynolds number -- 8.2 Low Reynolds number -- 8.3 High Reynolds number -- 9. Some Solutions of the Viscous Flow Equations -- 9.1 Introduction -- 9.2 Poiseuille flow -- 9.3 Rotating Couette flow -- 9.4 Stokes flow past a sphere -- 9.5 Low Reynolds number flow past a cylinder -- 10. Inviscid Flow -- 10.1 Introduction -- 10.2 Kelvin circulation theorem -- 10.3 Irrotational motion -- 10.4 Bernoulli's equation -- 10.5 Drag in inviscid flow: d'Alembert's 'paradox' -- 10.6 Applications of Bernoulli's equation -- 10.7 Some definitions -- 11. Boundary Layers and Related Topics -- 11.1 Boundary layer formation -- 11.2 The boundary layer approximation -- 11.3 Zero pressure gradient solution -- 11.4 Boundary layer separation -- 11.5 Drag on bluff bodies -- 11.6 Streamlining -- 11.7 Wakes -- 11.8 Jets -- 11.9 Momentum and energy in viscous flow -- 12. Lift -- 12.1 Introduction -- 12.2 Two-dimensional aerofoils -- 12.3 Three-dimensional aerofoils -- 12.4 Spinning bodies -- 13. Thermal Flows: Basic Equations and Concepts -- 13.1 Introduction -- 13.2 Equations of convection -- 13.3 Classification of convective flows -- 13.4 Forced convection -- 13.5 Flow with concentration variations (mass transfer) -- 14. Free Convection -- 14.1 Introduction -- 14.2 The governing non-dimensional parameters -- 14.3 The adiabatic temperature gradient -- 14.4 Free convection as a heat engine -- 14.5 Convection from a heated vertical surface -- 14.6 Thermal plumes -- 14.7 Convection in fluid layers -- Appendix: The Boussinesq approximation in free convection -- 15. Flow in Rotating Fluids -- 15.1 Introduction -- 15.2 Centrifugal and Coriolis forces -- 15.3 Geostrophic flow and the Taylor—Proud man theorem -- 15.4 Taylor columns -- 15.5 Ekman layers -- 15.6 Intrinsic stability and inertial waves -- 15.7 Rossby waves -- 15.8 Convection in a rotating annulus -- 16. Stratified Flow -- 16.1 Basic concepts -- 16.2 Blocking -- 16.3 Lee waves -- 16.4 Internal waves -- 16.5 Stratification and rotation -- 17. Instability Phenomena -- 17.1 Introduction -- 17.2 Surface tension instability of a liquid column -- 17.3 Convection due to internal heat generation -- 17.4 Convection due to surface tension variations -- 17.5 Instability of rotating Couette flow -- 17.6 Shear flow instability -- 18. The Theory of Hydro Dynamic Stability -- 18.1 The nature of linear stability theory -- 18.2 Onset of Bénard convection -- 18.3 Overstability -- 18.4 Rotating Couette flow -- 18.5 Boundary layer stability -- 19. Transition to Turbulence -- 19.1 Boundary layer transition -- 19.2 Transition in jets and other free shear flows -- 19.3 Pipe flow transition -- 20. Turbulence -- 20.1 The nature of turbulent motion -- 20.2 Introduction to the statistical description of turbulent motion -- 20.3 Formulation of the statistical description -- 20.4 Turbulence equations -- 20.5 Calculation methods -- 20.6 Interpretation of correlations -- 20.7 Spectra -- 20.8 The concept of eddies -- 21. Homogeneous Isotropic Turbulence -- 21.1 Introduction -- 21.2 Space correlations and the closure problem -- 21.3 Spectra and the energy cascade -- 21.4 Dynamical processes of the energy cascade -- 22. The Structure of Turbulent Flows -- 22.1 Introduction -- 22.2 Reynolds number similarity and self-preservation -- 22.3 Intermittency and entrainment -- 22.4 The structure of a turbulent wake -- 22.5 Turbulent motion near a wall -- 22.6 Large eddies in a boundary layer -- 22.7 The Coanda effect -- 22.8 Stratified shear flows -- 22.9 Reverse transition -- 23. Experimental Methods -- 23.1 General aspects of experimental fluid dynamics -- 23.2 Velocity measurement -- 23.3 Pressure and temperature measurement -- 23.4 Flow visualization -- 24. Practical Situations -- 24.1 Introduction -- 24.2 Cloud patterns -- 24.3 Waves in the atmospheric circulation -- 24.4 Continental drift and convection in the Earth's mantle -- 24.5 Solar granulation -- 24.6 Effluent dispersal -- 24.7 Wind effects on structures -- 24.8 Boundary layer control: vortex generators -- 24.9 Fluidics -- 24.10 Undulatory swimming -- 24.11 Convection from the human body -- 24.12 The flight of a boomerang -- Notation -- Problems -- Bibliography and References.

After observing the frequency of the social and moral values and their appearance, generally conflictive, in different media and legislative context. Development of personal and social and moral values is established as the cornerstone of the balance in a developed society. Development of social and moral values in our students is unknown and their measurement unclear. There is a bunch of research and methodological proposals in the work of attitudes and social and moral values in classrooms. However, the challenge remains that the student can internalize social and moral values, make them his own, and not only learn their meaning. From a university teaching experience with second-year students of Physical Activity and Sports Sciences Degree, there are deficiencies in this subject in the majority of students who capture these tools and attitudes only for a "relative meritocracy" or waiting for something in return. Consequently, some work tools are proposed for physical education, playful, through a gamified methodology, and close to the reality of the students, which makes these contents a vital experience. ; Tras observar la popularidad de los valores y su aparición, generalmente conflictiva, en diferentes medios de comunicación, pasando por un recorrido legislativo, donde se establece el desarrollo de valores personales y sociales como piedra angular del equilibrio en una sociedad desarrollada, surgen una serie de incógnitas relacionadas con los resultados obtenidos en materia de valores, del alumnado, siendo la medición de estos una asignatura pendiente. Existe un gran recorrido en la investigación y propuestas metodológicas en el trabajo de actitudes y valores en las aulas, no obstante, el principal reto sigue siendo que el alumnado sea capaz de interiorizar los valores, de hacerlos suyos, y no solo aprender su significado. Desde una experiencia en docencia universitaria con el alumnado del Grado de Ciencias de la Actividad Física y del Deporte de segundo curso, se encuentran carencias en esta materia en la mayoría de los alumnos/as que plasman estas herramientas y actitudes solo por una "meritocracia relativa" o esperando algo a cambio. En consecuencia, se plantea unas herramientas de trabajo para educación física escolar, lúdica, a través de una metodología gamificada y cercana a la realidad del alumnado, que hace de estos contenidos una experiencia vital. Abstract: After observing the frequency of the social and moral values and their appearance, generally conflictive, in different media and legislative context. Development of personal and social and moral values is established as the cornerstone of the balance in a developed society. Development of social and moral values in our students is unknown and their measurement unclear. There is a bunch of research and methodological proposals in the work of attitudes and social and moral values in classrooms. However, the challenge remains that the student can internalize social and moral values, make them his own, and not only learn their meaning. From a university teaching experience with second-year students of Physical Activity and Sports Sciences Degree, there are deficiencies in this subject in the majority of students who capture these tools and attitudes only for a "relative meritocracy" or waiting for something in return. Consequently, some work tools are proposed for physical education, playful, through a gamified methodology, and close to the reality of the students, which makes these contents a vital experience. ; Após observar a popularidade dos valores e seu aparecimento, geralmente conflituoso, em diferentes mídias, passa por uma jornada legislativa, onde o desenvolvimento de valores pessoais e sociais se estabelece como pedra angular do equilíbrio em uma sociedade desenvolvida, um série de incógnitas relacionadas com os resultados obtidos em matéria de valores, dos alunos, sendo a medição destes uma matéria pendente. Há um longo percurso de pesquisa e propostas metodológicas no trabalho de atitudes e valores em sala de aula, porém, permanece o principal desafio para que os alunos consigam internalizar os valores, torná-los seus, e não apenas aprender seus. significado. A partir de uma experiência de docência universitária com os alunos do Curso de Licenciatura em Atividade Física e Ciências do Esporte do segundo ano, há deficiências nessa matéria na maioria dos alunos que captam essas ferramentas e atitudes apenas por causa de uma "relativa meritocracia" Ou expectante algo em troca. Consequentemente, são propostas ferramentas de trabalho para a Educação Física escolar, lúdica, por meio de uma metodologia gamificada e próxima da realidade dos alunos, o que torna esses conteúdos uma experiência vital.

The Internet is one of the most successful inventions of recent times. The COVID-19 pandemic has, once again, proven the importance of the Internet to society, and this has further demonstrated how critical it is to build networks that are resilient, accessible and inclusive. However, the Internet in many African countries is still limited by both technical and regulatory challenges. It is along these lines that this thesis proposes a series of studies, supported by empirical evidence, to better understand the challenges of content delivery in African networks. The thesis starts by providing an understanding how the Internet is being used and consumed by low-income mobile Internet users in South African townships. By means of a mixed-methods study, combining quantitative network measurements with qualitative survey data, the thesis provides some useful insights about Internet usage patterns and the underlying reasons for specific user behaviour with regards to mobile data management. The research revealed how Internet usage patterns of users in low-resource settings are restrained by the lack of access, availability of services and data cost.It also reinforced the concept of locality of interest and at the same time showing that the mainstream Internet services remain very popular. Next, the thesis investigates the impediments faced by African users to access local content and cloud-based services. This is achieved through a study on web content hosting, focusing specifically on African local news and public sector websites. It was found that 85% of local news websites are hosted outside their respective countries by foreign companies, mostly in Europe and in the US. This section revealed how a majority of Africa's local content is still hosted remotely and this has a major incident on the Quality of Experience (QoE) of users in Africa. Considering the set of challenges of content delivery in Africa, companies such as Facebook and Google have introduced alternative mechanisms to deliver content to the end-user - purportedly using bandwidth-friendly and cost-effective technologies. This thesis performs an in-depth Quality of Service (QoS) analysis of: (1) Free Basics, a "zero-rated" service from Facebook and (2) Accelerated Mobile Pages (AMP), a mobile optimisation technology by Google. The aim of both Free Basics and AMP is to reduce the cost of access and improve the QoE on mobile devices through different techniques - albeit with some caveats pertaining to net neutrality and data privacy. However, the thesis reveals that Free Basics services provide weaker network performance than their paid counterparts, which contributes to a disjointed user experience. On the other hand, Google AMP pages can reduce traditional page sizes by a factor of 8 and the results show that Page Load Time (PLT) on African networks can significantly be improved. However, both Free Basics and Google AMP introduce serious concerns with regards to net neutrality and data privacy. One way to minimise the effects of cross-continental path is to host the content as close as possible to the end-users. For this, there must exist a robust interconnection ecosystem between African networks. The thesis performs a deep-dive in both intra-country and inter-country connectivity in Africa, looking into both delays and network path by means of a longitudinal active measurement study. The latter exposes interesting topological characteristics of cross-border connectivity and provides evidence on the existence of circuitous routing and a lack of peering within African networks. The thesis reveals a series of "communities", in which countries have built up low-delay interconnectivity, dispelling the myth that intra-delays in Africa are universally poor. Finally and taking into account the above, the thesis studies how the development of localised Internet infrastructure such as Internet Exchange Points (IXPs) and Data Centres (DCs) can help democratise access to local content. Using a simple multi-level maturity model, the thesis categorises the readiness of African countries to provide a localised Internet infrastructure. The thesis further explores the above hypothesis by estimating the effect of increasing the number of participants of an IXP on the local content activity of the country. The latter was achieved by using a fixed-effects econometric model and a positive correlation was found between the scale of an IXP and the local content activity. The thesis finally provides some key policy points on how to improve content delivery in African networks.

El crecimiento explosivo de las explotaciones confinadas de cerdos en todo el mundo ha generado preocupación en muchos investigadores sobre el impacto ambiental, la salud, la productividad ganadera y la generación de biogases asociados a este tipo de producción a gran escala. El objetivo de este trabajo fue estudiar la concentración y las emisiones de gas metano de diez tipologías constructivas diferentes en función de las variables climáticas, constructivas y de confort térmico. Para lograr el objetivo se plantearon las características constructivas más relevantes para mejorar el confort térmico de los animales, disminuir las emisiones de gases, y proponer las tipologías por grupo etareo en función del piso térmico y características constructivas que mejor se adaptan a las condiciones de producción animal. Adicionalmente se visitaron 10 granjas de etapa de ceba ubicadas en el departamento de Antioquia - Colombia, entre 800-2300 metros sobre el nivel del mar, únicamente fue posible encontrar tipologías que trabajaban con ventilación natural. En los alojamientos de los animales se realizaron mediciones climáticas con sensores manuales con cuyos resultados se calcularon los índices de humedad y temperatura de globo negro (BGHI) y el Índice de Humedad y Temperatura (THI) para cada una de las instalaciones, encontrando resultados entre los rangos 78 ± 5 - 68 ± 2; y 79 ± 4 - 69 ± 3 respectivamente. Las medidas de metano se tomaron con sensores ubicados en puntos intermedios de las áreas de entrada y salida de ventilación y se analizó el comportamiento de la concentración y emisión de metano de las instalaciones junto con la correlación y evolución temporal de las variables climáticas, índices de confort y tipologías constructivas. La información se analizó mediante estadística descriptiva, análisis de varianza (ANOVA) y análisis de componentes principales (PCA). Se encontraron resultados como: un promedio de tasa de Emisión de CH4 (ER) por instalación (Kg año -1) de 607.9, Potencial de Calentamiento Global (GWP) por instalación (Kg año-1) de 15197.42 y correlaciones significativas entre RE, frecuencia de limpieza (CF), unidad animal (AU), flujo de aire (Q), densidad animal (DA) y humedad relativa (HR). Esta es la primera investigación con este alcance reportada en Colombia, la cual será importante para futuras investigaciones y políticas gubernamentales. (Tomado de la fuente) ; The explosive growth of pig production at high densities in confined farms around the world has raised concerns among many researchers about the environmental impact, health and productivity of livestock and the production of biogases associated with this type of largescale production. The objective of this work was to study the concentration and emissions of methane gas from ten different construction typologies based on climatic, constructive and animal welfare variables. To achieve the objective, the most relevant constructive characteristics were proposed that allow improving the thermal comfort conditions of the animals, reducing gas emissions; and propose the typologies by age group according to the thermal floor and construction characteristics that best adapt to the conditions of animal production. Additionally, 10 fattening stage farms were visited located in the department of Antioquia - Colombia, between 800-2300 meters above sea level, it was only possible to find typologies that worked with natural ventilation, Measurements to climatic variables were carried out in the housing of the animals with manual sensors, with the results the humidity and temperature indices of the black globe (BGHI) and the Humidity and Temperature Index (THI) were calculated for each of the facilities, finding results between the ranges 78 ± 5-68 ± 2 and 79 ± 4-69 ± 3 respectively. Methane measurements were taken with sensors located at intermediate points of the ventilation inlet and outlet areas and the behavior of the concentration and emission of methane from the facilities was analyzed together with the correlation and temporal evolution of the climatic variables, indices of comfort and construction typologies. The information was analyzed using descriptive statistics, analysis of variance (ANOVA) and principal component analysis (PCA). Results were found such as an average CH4 Emission rate (ER) per facility (Kg year -1) of 607.9, Global Warming Potential (GWP) per facility (Kg year-1) of 15197.42 and significant correlations between RE, cleaning frequency (CF), animal unit (AU), air flow (Q), animal density (DA) and relative humidity (RH). This is the first investigation reported in Colombia, which will be important for future investigations and government policies. (Tomado de la fuente) ; Maestría ; Master en Medio Ambiente y Desarrollo ; Bioclimática aplicada a la agroindustria

Characterising the atmospheres of exoplanets is key to understanding their nature and provides hints about their formation and evolution. High resolution measurements of the helium triplet absorption of highly irradiated planets have been recently reported, which provide a new means of studying their atmospheric escape. In this work we study the escape of the upper atmospheres of HD 189733 b and GJ 3470 b by analysing high resolution HeI triplet absorption measurements and using a 1D hydrodynamic spherically symmetric model coupled with a non-local thermodynamic model for the HeI triplet state. We also use the H density derived from Ly alpha observations to further constrain their temperatures, mass-loss rates, and H/He ratios. We have significantly improved our knowledge of the upper atmospheres of these planets. While HD 189733 b has a rather compressed atmosphere and small gas radial velocities, GJ 3470 b, on the other hand with a gravitational potential ten times smaller, exhibits a very extended atmosphere and large radial outflow velocities. Hence, although GJ 3470 b is much less irradiated in the X-ray and extreme ultraviolet radiation, and its upper atmosphere is much cooler, it evaporates at a comparable rate. In particular, we find that the upper atmosphere of HD 189733 b is compact and hot, with a maximum temperature of 12 400(-300)(+400) K, with a very low mean molecular mass (H/He = (99.2/0.8) +/- 0.1), which is almost fully ionised above 1.1 R-P, and with a mass-loss rate of (1.1 +/- 0.1) x 10(11) g s(-1). In contrast, the upper atmosphere of GJ 3470 b is highly extended and relatively cold, with a maximum temperature of 5100 +/- 900 K, also with a very low mean molecular mass (H/He = (98.5/1.5)(-1.5)(+1.0)-1.5+1.0 ), which is not strongly ionised, and with a mass-loss rate of (1.9 +/- 1.1) x 10(11) g s(-1). Furthermore, our results suggest that upper atmospheres of giant planets undergoing hydrodynamic escape tend to have a very low mean molecular mass (H/He greater than or similar to 97/3). © ESO 2021. ; We thank the referee for very useful comments. CARMENES is an instrument for the Centro Astronomico HispanoAleman (CAHA) at Calar Alto (Almeria, Spain), operated jointly by the Junta de Andalucia and the Instituto de Astrofisica de Andalucia (CSIC). CARMENES was funded by the Max-Planck-Gesellschaft (MPG), the Consejo Superior de Investigaciones Cientificas (CSIC), the Ministerio de Economia y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through projects FICTS-2011-02, ICTS-2017-07-CAHA-4, and CAHA16-CE-3978, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Institut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the MINECO, the Deutsche Forschungsgemeinschaft through the Major Research Instrumentation Programme and Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. We acknowledge financial support from the Agencia Estatal de Investigacion of the Ministerio de Ciencia, Innovacion y Universidades and the ERDF through projects ESP2016-76076-R, ESP2017-87143-R, PID2019-110689RB-I00/AEI/10.13039/501100011033, BES-2015-074542, PGC2018-099425-B-I00, PID2019-109522GB-C51/2/3/4, PGC2018-098153-BC33, AYA2016-79425-C3-1/2/3-P, ESP2016-80435-C2-1-R, and the Centre of Excellence "Severo Ochoa" and "Maria de Maeztu" awards to the Instituto de Astrofisica de Canarias (SEV-2015-0548), Instituto de Astrofisica de Andalucia (SEV-2017-0709), and Centro de Astrobiologia (MDM-2017-0737), and the Generalitat de Catalunya/CERCA programme. T.H. acknowledges support from the European Research Council under the Horizon 2020 Framework Program via the ERC Advanced Grant Origins 832428. A.S.L. acknowledges funding from the European Research Council under the European Union's Horizon 2020 research and innovation program under grant agreement No 694513. ; Peer reviewed

Acoustics is of interest for applications pertaining to defence and security since it can provide a passive, omnidirectional and non-line-of-sight survey. In a military context, microphone arrays are for instance used to detect, localize and classify explosions, artillery fire or gunshots. However, time signatures recorded a few hundred meters from the source may be very sensitive to the environmental conditions since significant propagation effects related to the mean stratification of the atmosphere, turbulence, topography or ground impedance are expected. The combined impact of these effects is as yet little documented, and this lack of knowledge can degrade the performance of military systems.Numerical simulations are an interesting and complementary alternative to experiments to better understand these interactions since the input parameters can be controlled. Battlefield acoustics, however, typically involves very loud, impulse sounds, which propagate with short wavelengths over relatively long distances. Combined with the three-dimensional volume modeling required for turbulence or topology effects, such numerical predictions are very challenging in terms of computational cost even with currently available computing capabilities. One of the purposes of this work is to develop a new version of the in-house finite-difference time-domain solver (FDTD) in order to match these specifications. Time-domain 3D simulations being relatively new, a number of scientific advances were achieved regarding ground and source modeling in the time domain or the effectiveness of non-reflecting boundary conditions (PML).Still, comparison with measurements is necessary to ensure the accuracy of numerical predictions in realistic conditions. Acoustic measurements were thus carried out in Germany for several days in various meteorological conditions. The formed database provides original insights into the propagation effects on impulse sounds over up to several hundreds of meters. An excellent agreement is obtained with deterministic simulations for all considered configurations. These results pave the way for further assessment of spatial and temporal coherence losses, and their influence on the performance of microphone arrays. ; L'acoustique a un intérêt certain pour des applications de sécurité et de défense puisqu'elle permet une surveillance passive, omnidirectionnelle et sans ligne de vue directe. Dans le contexte militaire, des antennes de microphones sont par exemple utilisées pour détecter, localiser et classifier des explosions, des tirs d'artillerie ou des tirs d'armes de poing. Les signatures temporelles enregistrées à quelques centaines de mètres de la source peuvent cependant présenter une grande sensibilité aux conditions environnementales, et notamment, en milieu ouvert, au sol et à la micrométéorologie. Des effets de propagation importants liés à la stratification moyenne de l'atmosphère, la turbulence, la topographie ou l'impédance du sol sont en effet attendus. L'influence combinée de ces effets reste peu documentée, et peut se traduire par une dégradation des performances des systèmes militaires. La simulation numérique est une alternative intéressante et complémentaire à l'approche expérimentale pour mieux comprendre ces interactions, puisqu'elle permet le contrôle des paramètres d'entrée. L'acoustique du champ de bataille fait cependant intervenir des sons à caractère impulsionnel et de grande amplitude, qui se propagent sur de relativement longues distances et présentent de petites échelles spatiales ; la prise en compte des effets de turbulence ou de topologie imposent de plus une modélisation volumique tridimensionnelle. Ces aspects sont très contraignants en terme de coûts de calcul, même avec les capacités de calcul modernes. Un premier objectif de cette thèse consiste à développer une nouvelle version du modèle de différences finies dans le domaine temporel (FDTD) initialement disponible pour permettre de répondre à ces spécifications. Les simulations temporelles en trois dimensions étant relativement peu répandues, un certain nombre d'avancées scientifiques ont été requises par rapport aux travaux antérieurs, concernant la prise en compte des sources, la modélisation des sols ou l'efficacité des conditions denon-réflexion (PML).La confrontation avec l'expérience s'avère toutefois indispensable pour s'assurer de la qualité des prédictions numériques en conditions réalistes. Des mesures acoustiques originales ont ainsi été réalisées en Allemagne pendant plusieurs jours et pour différentes conditions atmosphériques afin de documenter la variabilité des sons impulsionnels, pour des distances de propagation de plusieurs centaines de mètres. Un excellent accord est obtenu avec des simulations numériques déterministes pour toutes les configurations considérées. Ces résultats ouvrent la voie vers l'étude des pertes de cohérences spatiales et temporelles et leur influence sur les performances des antennes microphoniques.