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Ground-penetrating radar (GPR) technology finds applications in many areas such as geophysical prospecting, archaeology, civil engineering, environmental engineering, and defence applications as a non-invasive sensing tool [3], [6], [18]. One key component in any GPR system is the receiver/transmitter antenna. Desirable features for GPR antennas include efficient radiation of ultra-wideband pulses into the ground, good impedance matching over the operational frequency band, and small size. As the attenuation of radio waves in geophysical media increases with frequency [9], [13], ground-penetrating radars typically operate at frequencies below 1GHz [4]. For either impulse [13] or steppedfrequency continuous-wave applications [17], the wider the frequency range, the better the range resolution of the radar. Continuous wave multi-frequency radars are advantageous over impulse radars in coping with dispersion of the medium, the noise level at the receiver end, and the controllability of working frequency. It requires, however, mutual coupling between the transmit (Tx) and receive (Rx) antennas, which determines the dynamic range of the sys-tem, to be kept as small as possible [12].

Ultra-wideband radio technology (UWB-RT) inherited a potential of extremely high rate of data communications, Claude Shannon discovered this in 1948 and derived the later-called-as Shannon-Hartley‘s channel capacity laws. This famous theoretical law however was not able to substantiate in practice until the development of the sampling oscilloscope by Hewlett-Packard in 1962, which, in accordance with the Nyquist-Shannon sampling theorem, was then capable to reconstruct at-that-time rather large UWB signals (Wilson, 2002).

The main focus of this Chapter was targeted on novel approaches to compatibility of particles with polymer matrices and detail analysis of rheology-morphology interrelationships. Rather attractive method of mixing based on knowledge of rheological behavior of polymers at high shear rates was proposed and studied. The major fraction of ND around 40 nm and absence of agglomerates of micron dimensions allow us to recommend this method for industrial application. For successful processing of nanocomposite precursors interrelationships between rheological properties and stream morphology is extremely important and depending on the task, it is possible to obtain either chaotic or regular distribution of filler particles. These data were obtained by combining rheological and optical or structural methods. Hypothesis over the main driving force of particles ordering based on regular elastic instability of polymer matrix causing ordering of particles was proposed. Mechanical characterization confirms the strong influence of dimensional homogeneity of particles on final properties of nanocomposites.

OA-fund TU Delft

Our world is a complex socio-technical system-of-systems (Chappin & Dijkema, 2007; Nikolic, 2009). Embedded within the geological, chemical and biological planetary context, the physical infrastructures, such as power grids or transport networks span the globe with energy and material flows. Social networks in the form of global commerce and the Internet blanket the planet in information flows. While parts of these global social and technical systems have been consciously engineered and managed, the overall system-of-systems (SoS) is emergent: it has no central coordinator or manager. The emergence of this socio-technical SoS has not been without consequences: the human species is currently facing a series of global challenges, such as resource depletion, environmental pollution and climate change. Tackling these issues requires active policy and management of those socio-technical SoS. But how are we to design policies if policy makers and managers have a limited span of control over small parts of the global system of systems?