Solar energy and the aeronautics industry

An introduction to the physical aspects of solar energy, incidental energy and variations in solar flux is presented, along with an explanation of the physical principles of obtaining solar energy. The history of the application of solar energy to aeronautics, including the Gossamer Penguin and the Solar Challenger is given. Finally, an analysis of the possibilities of using a reaction motor with hybrid propulsion combining solar energy with traditional fuels as well as calculations of the proposed cycle and its mode of operation are given

Stopping light in two dimensional quasicrystalline waveguides

The introduction of defects in photonic lattices generally allows to control the localization and the propagation of light. While point defects are conventionally used in order to obtain localized photonic states, linear defects are introduced for waveguiding EM waves. In this work we demonstrate the possibility of obtaining localized states also in a waveguiding configuration, by using quasicrystalline lattices. This result opens a new range of possibilities in designing optical circuits, in which the localization- propagation switch is easly obtainable by mechanical or opto-electric methods

New insight into cataract formation -- enhanced stability through mutual attraction

Small-angle neutron scattering experiments and molecular dynamics simulations combined with an application of concepts from soft matter physics to complex protein mixtures provide new insight into the stability of eye lens protein mixtures. Exploring this colloid-protein analogy we demonstrate that weak attractions between unlike proteins help to maintain lens transparency in an extremely sensitive and non-monotonic manner. These results not only represent an important step towards a better understanding of protein condensation diseases such as cataract formation, but provide general guidelines for tuning the stability of colloid mixtures, a topic relevant for soft matter physics and industrial applications.Comment: 4 pages, 4 figures. Accepted for publication on Phys. Rev. Let

Passage-time statistics of superradiant light pulses from Bose-Einstein condensates

We discuss the passage-time statistics of superradiant light pulses generated during the scattering of laser light from an elongated atomic Bose-Einstein condensate. Focusing on the early-stage of the phenomenon, we analyze the corresponding probability distributions and their scaling behaviour with respect to the threshold photon number and the coupling strength. With respect to these parameters, we find quantities which only vary significantly during the transition between the Kapitza Dirac and the Bragg regimes. A possible connection of the present observations to Brownian motion is also discussed.Comment: Close to the version published in J. Phys.

Mesoscopic Phase Fluctuations: General Phenomenon in Condensed Matter

General conditions for the occurrence of mesoscopic phase fluctuations in condensed matter are considered. The description of different thermodynamic phases, which coexist as a mixture of mesoscopically separated regions, is based on the {\it theory of heterophase fluctuations}. The spaces of states, typical of the related phases, are characterized by {\it weighted Hilbert spaces}. Several models illustrate the main features of heterophase condensed matter.Comment: 23 pages, Latex, no figure

Åndelig dannelse og vejledning - et udsnit af mulige rammebetingelser

Artiklen beskæftiger sig med nogle af rammebetingelserne – de kulturelle, samfundsmæssige og teologiske – for åndelig dannelse og vejledning. Den ofte belastede identitet og tydelige åndelige længsel – styret eller formet af den nye subjektivitet – har brug for eksistentielle tolkningsrum. Både teologi og kirke skal vove at tolke og navngive det navneløse, også den løse tro og det kaosprægede i den flydende modernitet. Den kristne teologi har adkomst til mange rige resurser og traditioner. Disse resurser kan være menneskelivets hukommelse – og verdens ‘hardisk’. Troen, livet og tjenesten formes og dannes i tæt forbindelse med disse kilder. Og kirken er som fællesskab et unikt og konkret resursested, hvis det også fungerer som åbent grænseområde. Grænsefællesskabet er fyldt med håb og muligheder for de åndeligt søgende. At leve med Gud i en kærlighedsrelation kan ikke læres med hovedet. Det må erfares i hjertet