8.1 INTRODUCTION More than half of the people in sub-Saharan Africa live on less than US$ 1.25 per day, and nearly 30% do not receive sufficient nourishment to maintain daily health (UN, 2009a). These figures are expected to rise as a result of the recent global financial crisis that has led to an increase in food prices. Food for Peace (FFP), the program CONTENTS

Kurzfassung. Bei dem bildgebenden Verfahren Magnetic Particle Imaging (MPI) wird die Ortskodierung dadurch erzielt, dass ein sogenannter feldfreier Punkt (FFP) auf einer Trajektorie durch das Betrachtungsfeld gefahren wird. Als eine der besten Möglichkeiten haben sich dafür Lissajous-Figuren erwiesen. Ein Nachteil ist dabei, dass in einem MPISystem die Hardware auf feste Frequenzen abgestimmt w...

The radiation characteristics of hemispherical DRA elements mounted on or embedded in a hollow circular cylindrical ground structure are investigated. The performance of the DRA array which operates at about 1.8 Ghz, is studied. Factors influencing the array performance, such as the number of elements and element spacing are explained. The perforated dielectric technique is used to design the a...

Gamma ray bursts are often modelled as jet-like outflows directed towards the observer; the cone angle of the jet is then commonly inferred from the time at which there is a steepening in the power-law decay of the afterglow. We consider an alternative model in which the jet has a beam pattern where the luminosity per unit solid angle (and perhaps also the initial Lorentz factor) decreases smoo...

In recent works the authors have shown that it is possible to retrieve the full velocity vector of a moving target from Synthetic Aperture Radar (SAR) data using a single sensor. This paper addresses the design of the radiation antenna pattern leading to the best velocity estimates. Aiming at this goal, the Fisher information matrix for the unknown moving targets velocity parameters is computed...

If A q (β, α, k) is the scattering amplitude, corresponding to a potential q ∈ L 2 (D), where D ⊂ R 3 is a bounded domain, and e ikα·x is the incident plane wave, then we call the radiation pattern the function A(β) := A q (β, α, k), where the unit vector α, the incident direction, is fixed, and k > 0, the wavenumber, is fixed. It is shown that any function f (β) ∈ L 2 (S 2) with a small norm, ...

A cylindrical hat-loaded method is employed to make monopoles behave as dual band resonators. The two frequency bands are obtained by perturbing higher propagation modes by modifying the hat length. The longer the cylindrical hat is, the lower the resonant frequencies are obtained. The hat length behaves as an inductive load, also increasing the electric length of the monopole. As a result, a c...

There are many methods for identifying the shape and location of scatterers from far field data. We take the view that the connections between algorithms are more illuminating than their differences, particularly with regard to the Linear Sampling Method [7], the Point Source Method [26] and the MUSIC algorithm [11]. Using the first two techniques we show that, for a scatterer with Dirichlet bo...

If Aq(β, α, k) is the scattering amplitude, corresponding to a potential q ∈ L 2(D), where D ⊂ R3 is a bounded domain, and eikα·x is the incident plane wave, then we call the radiation pattern the function A(β) := Aq(β, α, k), where the unit vector α, the incident direction, is fixed, and k > 0, the wavenumber, is fixed. It is shown that any function f(β) ∈ L2(S2), where S2 is the unit sphere i...