L'Univers, en dehors de notre Galaxie, est baigné de nombreux rayonnements, le principal étant observable dans le domaine des ondes radio centimétriques et millimétriques: le fond cosmologique (ou CMB pour {\it Cosmic Microwave Background}), corps noir de température actuelle 2.7 Kelvin. Découvert dans les années soixante, et largement étudié depuis pour ses infimes fluctuations de température et de polarisation, il se propage librement depuis une époque située environ 400000 ans après le big-bang. Il nous renseigne sur l'état de l'Univers primordial, sur son contenu, ainsi que sur certains processus physiques ayant eu lieu ultérieurement, comme la réionisation ou la formation des amas de galaxie. Un autre rayonnement d'importance cosmologique a été découvert il y a seulement quatorze ans dans les données du satellite COBE, mais ici dans le domaine de l'infrarouge lointain, vers 200 microns de longueur d'onde: le {\bf rayonnement fossile des galaxies}, ou fond diffus extragalactique infrarouge. Il est environ 50 fois moins intense que le fond cosmologique (pic à pic, ou de 20 à 40 fois moins en intégrale). Cette détection a constitué une grande surprise vu la grande intensité relative de l'infrarouge lointain par rapport à la partie visible provenant directement des étoiles. Ce fond diffus a pour origine l'émission de toutes les galaxies depuis leur formation, et résume ainsi toute leur histoire. Il est donc permis d'écrire, presque sans ironie, que {\bf la nuit n'est pas noire}, dans la mesure où, si nos yeux (avec le concours d'une hypothétique fenêtre atmosphérique) étaient sensibles aux rayonnements infrarouge lointain, millimétrique et centimétrique, ils verraient une nuit brillante de rayonnements cosmologiques. Notons que la question de la nuit noire - connue sous le nom de paradoxe d'Olbers Chéseaux - est ancienne, fertile, et touche aux fondements de la description et la compréhension de notre Univers physique, de son origine et de son évolution. Mesurer précisément ce rayonnement de fond infrarouge et comprendre la nature des galaxies qui en sont à l'origine et leur évolution, constituent l'une des thématiques importantes de la cosmologie observationnelle d'aujourd'hui. Je détaille, dans ce manuscrit de HDR, quelques-unes de mes contributions à l'étude statistique des galaxies infrarouges, à la mesure et l'interprétation du rayonnement extragalactique, et esquisse quelques perspectives. Le document de la HDR -- soutenue le 21 septembre 2010 à l'Institut d'Astrophysique Spatiale, Orsay -- et ses annexes sont disponibles en ligne sur http://www.ias.u-psud.fr/dole/hdr/

Cuando observamos el cielo con los instrumentos más avanzados en la frecuencia de las microondas, los fotones que vemos fueron originados en regiones muy diferentes del universo. La mayoría proceden de nuestra propia galaxia (emisión difusa de sincrotrón, free-free y polvo), otros se originan en galaxias y cúmulos de galaxias muy lejanos, y, finalmente, una fracción tendrá su origen en la radiación del Big Bang, conocida como la Radiación del Fondo Cósmico de Microondas. Esta radiación está contaminada por las otras y su separación de ellas de una forma satisfactoria sigue siendo un problema abierto. En esta tesis exploraremos diferentes técnicas basadas en filtros lineales para detectar y separar uno de estos contaminantes, la contribución a la señal que se observa de radio galaxias y galaxias infrarrojas lejanas. Éstas son conocidas como fuentes puntuales porque aparecen como objetos puntuales no resueltos -- debido a las típicas resoluciones angulares de los instrumentos usados en los experimentos. En primer lugar, vamos a estudiar las propiedades de una familia de filtros adaptados para la detección de fuentes puntuales, donde modificamos la escala del filtro y usamos un test de Neyman-Pearson para definir la región de aceptación. En segundo lugar, consideramos un nuevo filtro (BSAF) que tiene dos parámetros que se pueden optimizar para maximizar el número de detecciones reales fijado un número de detecciones espurias. En tercer lugar, extendemos el BSAF al caso dos-dimensional y lo comparamos con la ondícula de sombrero mejicano (MHW). En cuarto lugar, estudiamos una nueva técnica de fusión de lineal y cuadrática de imágenes. En quinto lugar, comparamos tres filtros usando simulaciones realistas de Planck. En sexto lugar, para terminar, usamos el segundo miembro de la familia de ondículas de sombrero mejicano para hacer una detección no-ciega en las cinco frecuencias del satélite WMAP, analizando 2491 objetos observados a 5 GHz y produciendo un catálogo de 932 objetos observados a 3σ y 380 a 5σ. / When we observe the sky with the most advanced instruments operating at microwave frequencies, the photons that we see were originated in very different regions in the universe. Most of them come from our own Galaxy (diffuse synchrotron, free-free and dust emission), others come from very distant galaxies and clusters of galaxies, and, finally, a fraction will have their origin in the relic radiation of the Big Bang, known as the Cosmic Microwave Background Radiation. This radiation is contaminated by the other components and the separation of the different emissions in a satisfactory way is still an open problem. In this thesis we will explore different techniques based on linear filters to detect and separate one of the contaminants, the contribution to the observed signal of distant radio and infrared galaxies. These galaxies are known as extragalactic point sources because, for the angular resolution of the typical experiments in microwave frequencies, they appear as point-like unresolved objects. First, we will study the performance of a family of matched filters when detecting point sources, where we allow the scale of the filter to be modified and where we introduce a Neyman-Pearson test to define the region of acceptance. Second, we will consider a new one-dimensional linear filter, the Biparametric Scale-Adaptive Filter (BSAF), that has two parameters that can be optimised to maximise the number of real detections for a fixed number of spurious detections, used in conjuction with a Neyman-Pearson test. Third, we will extend the BSAF to two dimensions, and compare it with the Mexican Hat Wavelet. Fourth, we will explore a new technique that combines lineal and quadratic fusion of images with linear filters, testing it with realistic simulations of one of the Planck satellite channels. Fifth, we will study in detail the performance of three filters, the Matched filter and two members of the Mexican Hat wavelet in realistic simulations of the nine channels of Planck. To conclude, we will use the second member of the Mexican Hat Family to do a non-blind study in the five frequencies of WMAP of a complete sample of 2491 sources observed at 5 GHz, producing a catalogue of 932 objects detected above 3σ and a catalogue of 380 objects observed above 5σ.

Steel industry is a highly polluted industry and one of the most important stationary sources in Kaohsiung City. The steel manufacturing process could emit a huge amount of particles, such as the sintering process, the blast furnace operation, and the raw material handling process. Suspended particles emitted from steel industry could deteriorate ambient air quality and cause adverse effects on human health. In order to understand the impact of steel industry on ambient air quality in Siaogang District and to identify potential pollution sources, this study selected a integrated steel manufacturing plant located at Siaogang District to conduct a sampling protocol of suspended particulate matter (PM) at ambient sites (A1~A5) and sensitive sites (S1~S5) from July 2011 to March 2012. The size distribution of suspended particles in four seasons was measured with PM10 high-volume samplers, dichotomous samplers, and MOUDI for 3 days (24 hours for single sampling), and dustfall samplers for one month, to investigate the spatial distribution and temporal variation of PM concentration. After sampling, the physicochemical properties of PM, including mass concentration, particle size distribution, dustfall concentration, water-soluble ionic species, metallic elements, and carbonaceous contents, were further analyzed. Field measurement of ambient PM showed that the averaged ambient PM10 concentration (53.54 - 203.56 £gg/m3) were higher than sensitive sites (55.06 - 140.07 £gg/m3) and the averaged ambient PM2.5 concentration of ambient (23.10 - 120.21£gg/m3) were higher than sensitive sites (12.52 - 65.62 £gg/m3). No matter ambient or sensitive sites, it showed a tendency of lower concentration in summer, indicating that concentration variation of PM10 and PM2.5 were highly affected by meteorological factors (such as wind direction, wind speed, and relative humidity) in Siaogang District. Furthermore, a t-test result showed that ambient and sensitive sites have similar pollution sources since the p-values were in significantly different. Chemical analysis of PM results showed that the most abundant water-soluble ionic species of PM at the ambient and sensitive sites were secondary inorganic aerosols (SO42-, NO3-, and NH4+) and [NO3-]/[SO42-] showed that ionic species were mainly emitted from stationary sources. Fe, Al, K and Ca were the major metallic elements of this study, and the major pollution sources contain industries, traffics, and road dusts. Additionally, the raw material handling process was the major pollution source of PM. Correlation analysis of OC and EC showed that PM at ambient and sensitive sites were originated from primary sources, such as vehicles, industries, road dusts, and human activities. Results obtained from PCA and CMB receptor modeling showed that both PM2.5 and PM10 highly correlated with wind direction in different season and the major pollution sources were industry pollution (including petroleum refineries, power plants, waste incinerators, consistent operating steel mills and electric arc furnace steel mills, etc.), followed by local traffics and derivative. Furthermore, marine aerosols were one of the important pollution sources at sensitive sites (S1, S4, and S5) where close to the ocean.

In the contemporary global world, corporate governance is one of the most frequently referred business term. This study examines the corporate governance compliance reports submitted to Capital Markets Board (CMB) by the publicly traded companies on Istanbul Stock Exchange (ISE). In the analysis, relation among corporate governance compliance and size and ownership structure is investigated. Corporate governance compliance scores of the companies are obtained from Corporate Governance Index constructed based on CMB&rsquo / s Corporate Governance Principles. The results indicate that size for the entire sample of companies has positive effect on total corporate governance score and all sub index scores / in addition, under different sector categories, size affects total and sub index scores positively except service sector. The public ownership percentage singly measures ownership concentration and it affects corporate governance scores positively except stakeholders and board of directors sub indices scores for all companies. For sector categories, ownership concentration has positive effect on only general corporate governance compliance and shareholders sub index scores for finance companies. Foreign ownership percentage has positive effect on shareholders sub index score derived for all and manufacturing sector companies while its effect is negative for all other scores measured. The findings of this study contribute to the relevant literature and welcome new research initiatives within the same area in Turkey.

>Magister Scientiae - MSc / Previous studies have shown that the use of chloride mass balance (CMB) method is a suitable and practical approach to estimate groundwater recharge. This enables the prediction of groundwater availability to inform practical strategies for managing groundwater resources. However, such studies have largely applied the chloride mass balance method on national and catchment scales with limited focus on quaternary catchment level (QCL). Neglecting the chloride mass balance method at quaternary catchment level limits practical management and utilization of water resources at quaternary catchment level. The goal of the current study was to prove that 1) the chloride mass balance method should be applied at quaternary catchment level to ensure practical assessment of groundwater availability and that 2) chloride mass balance assessment should be accompanied with supplementary methods for its application in quaternary catchments of similar physiographic and hydrogeologic conditions. To achieve these goals, the present study assessed the application of chloride mass balance method on a pilot scale used alongside rainwater infiltration breakthrough (RIB) and water table fluctuation (WTF) methods to estimate the groundwater recharge as an indicator of groundwater availability. The pilot area (PA) was in the upper Berg River catchment in Western Cape in South Africa. Chloride concentrations were determined in groundwater samples collected from boreholes and rain water in rain gauges in the pilot area. Rainfall and borehole water levels in the pilot area were used in water table fluctuation and rainwater infiltration breakthrough analyses. As quality assurance, the specific yield data obtained from the pumping test were compared to those determined with the linear regression model. This established the reliability of the analysis i.e. the relationship between groundwater level and rainfall. Mean groundwater recharge values calculated using the chloride mass balance, rainwater infiltration breakthrough and water table fluctuation methods were 27.6 %, 23.67 %, and 22.7 % of the total precipitation received in the catchment, respectively. These results indicate that the use of these three methods have potential to estimate groundwater recharge at quaternary level which is the basic unit of water management in South Africa. These findings agree with previous studies conducted in the same catchment that indicate that mean groundwater recharge ranges between 18.6 % and 28 % of the total precipitation. In the future, these methods could be tested in catchments which have physiographic and hydrogeologic conditions similar to those of the current pilot area. / African Union (AU)

The cosmic microwave background (CMB) provides unprecedented details about the history of our universe and helps to establish the standard model in modern cosmology. With the ongoing and future CMB observations, higher precision can be achieved and novel windows will be opened for studying different phenomena. Non-Gaussianity is one of the most exciting effects which fascinate many cosmologists. While numerous alternative inflationary models predict detectable primordial non-Gaussianities generated during inflation, the single-field slow-roll inflation of the standard model is known to produce negligible non-Gaussianities. However, post-inflationary processes guarantee the generation of non-Gaussianities through the nonlinear evolution of our universe after inflation, regardless of the underlying inflationary theory. These non-Gaussianities not only may contaminate the potential primordial non-Gaussian signals, but also may offer independent tests for late-time physics (such as General Relativity). Therefore, it is of great interest to study them quantitatively. In this thesis, we will study the post-inflationary non-Gaussianities in two main aspects. First, we calculate the CMB bispectrum imprinted by the 2nd-order perturbations during recombination. We carry out a numerical calculation including all the dominant effects at recombination and separate them consistently from the late-time effects. We find that the recombination bispectrum is subdominant compared to the ISW-lensing bispectrum. Although the effect will not be detectable for the Planck mission, its signal-to-noise is large enough that they present themselves as systematics. Thus, it has to be taken into account in future experiments. Second, we formulate the lensing, redshift and time-delay effects through the Boltzmann equation. The new formalism allows us to explicitly list out all the approximations implied in the canonical remapping approach. In particular, we quantify the correction of the CMB temperature power spectrum from the lens-lens couplings and confirm that the correction is small.

Today, there are only a limited number of surveys of the sky at 1 to 20 GHz. These frequencies lie below the all-sky surveys of WMAP and Planck, but are critical in constraining the spectral slope of Galactic synchrotron emission. Knowledge of the large-scale spectral morphology of Galactic synchrotron emission is critical in the understanding of the interstellar medium and the weak signal from the polarised cosmic microwave background. Recently, ground based observations from S-PASS, C-BASS and the QUIJOTE Multifrequency Instrument (MFI) have been populating these missing frequencies. This thesis presents the first QUIJOTE MFI maps of the Northern sky in total intensity at 11, 13, 17 and 19 GHz, and the first single-dish mapping observations of Lynds dark cloud, LDN1622 at 5 and 13.7GHz. The observations from both instruments are used to probe the nature of spinning dust emission on degree and arcminute scales within the Galaxy. A full data reduction and calibration pipeline for QUIJOTE MFI time-ordered-data is described. The absolute flux density scale uncertainty of the MFI data is between 2 and 3 per cent. The pipeline characterises key properties of the MFI, such as the RFI sources, beams, bandpasses, 1/f noise and more. A key part of the pipeline was the development of an MPI ready Destriping map-maker and a maximum-likelihood map-maker. The map-making code can be applied to a range of different single-dish instruments and is used to reduce both the QUIJOTE MFI wide-survey maps of the Northern sky, and the GBT arcminute resolution raster observations of LDN 1622. A detailed discussion is given on the simulations used to test the integrity of the map-making implementation. Parametric model fitting to the SEDs of four spinning dust emission regions is performed. The MFI wide-survey maps are used in conjunction with existing multifrequency 1degree survey data. The addition of MFI maps is used to confirm the previously tentative spinning dust emission source LDN 1582/84. The mean peak frequency of spinning dust emission over the four spinning dust sources is found to be ⟨νsp⟩ = 27.2 +/- 0.7 GHz, and the mean ratio of the peak spinning dust brightness over the dust optical depth is ⟨Asp/τ250⟩ = 1.24 +/- 0.18 × 104 Jy/τ250. Spectral index maps are derived from the MFI wide-survey data in combination with 408 MHz and WMAP 23 GHz data. These maps are used to further quantify the ubiquity of spinning dust emission throughout the Galaxy. The results show that the median flux density spectral index within the inner Galactic disk for |b| < 2° is 0.24 +/- 0.07. This implies that at 23 GHz, spinning dust emission contributes 25 +/- 5 per cent of the total integrated emission within the inner disk of the Galaxy.

Le fond diffus cosmologique (CMB) est la première lumière libérée par l’Univers.À ce titre, elle constitue la photographie la plus ancienne à laquelle nous ayons accès.Ces photons recèlent des trésors d’informations capables de nous renseigner tant sur le contenu énergétique de l’Univers que sur son histoire. En retraçant son évolution jusqu’aujourd’hui, on est capable d’établir des scénarios quant à la période qui a précédé l’émission du CMB, inaccessible aux observations. Plus particulièrement,la plupart des modèles s’accordent à dire que l’Univers aurait connu juste après le Big Bang une période d’expansion exponentielle qualifiée d’inflation. L’un des défis majeurs de la cosmologie consiste à confirmer et contraindre ces modèles en cherchant sur le CMB les empreintes théoriques laissées par l’inflation : un motif de polarisation qualifié de mode B. Cependant, ce signal est attendu à un niveau très faible, sa détection requiert donc la mise en place d’instruments extrêmement sensibles. Cette thèse s’inscrit dans l’effort technologique mené au sein du projet QUBIC pour cette quête. Dans cette optique on s’est intéressé aux détecteurs, des matrices de plusieurs centaines de bolomètres supraconducteurs. Dans un premier temps, on a défini une méthode permettant de dimensionner les détecteurs et la matrice pour répondre au mieux à nos attentes à travers l’ajustement de paramètres pertinents. Puis on a mené pour la première fois dans la collaboration toute la réalisation d’une matrice de 256détecteurs sur laquelle on a par la suite effectué et exposé des tests préliminaires prometteurs pour la future implémentation du plan focal de QUBIC. / The cosmic microwave background (CMB) is the very first light of the Uni- verse and thus constitutes the oldest picture of its initial state. These photons carry valuable information constraining both the energy content and the history of the Universe. CMB observations allow us to reconstruct what occurred before the CMB anisotropies were imprinted. The most promising theoretical models all postulate an epoch of exponential expansion known as inflation just after the Big Bang. One of the major challenges of observational cosmology is hence to confirm or falsify inflation as well as to discover how inflation was realized in a particular model by searching for its imprint on the CMB polarization B-mode. This signal is however expected to be extremely weak and its detection requires a very sensitive experiment. This thesis reports on contributions to the technology development for the innovative QUBIC instrument, focusing on the perfection of an array of several hundreds of supercon- ducting bolometric detectors. A method was defined to design the detector array through tuning the relevant parameters to best meet our requirements. Then a 256- detector prototype array was fully manufactured and characterized. The preliminary characterization gave promising results for the forthcoming implementation of the QUBIC focal plane.

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