Places of art, traces of fire. A contextual approach to anthropomorphic figurines in the Pavlovian

Human Origin

Development of a broadband and squint-free Ku-band phased array antenna system for airborne satellite communications

Novel avionic communication systems are required for various purposes, for example to increase the flight safety and operational integrity as well as to enhance the quality of service to passengers on board. To serve these purposes, a key technology that is essential to be developed is an antenna system that can provide broadband connectivity within aircraft cabins at an affordable price. Currently, in the European Commission (EC) 7th Framework Programme SANDRA project (SANDRA, 2011), a development of such an antenna system is being carried out. The system is an electronically-steered phased-array antenna (PAA) with a low aerodynamic profile. The reception of digital video broadcasting by satellite (DVB-S) signal which is in the frequency range of 10.7-12.75 GHz (Ku-band) is being considered. In order to ensure the quality of service provided to the passengers, the developed antenna should be able to receive the entire DVB-S band at once while complying with the requirements of the DVB-S system (Morello & Mignone, 2006). These requirements, as will be explained later, dictate a broadband antenna system where the beam is squint-free, i.e. no variation of beam pointing direction for all the frequencies in the desired band. Additionally, to track the satellite, the seamless tunability of the beam pointing direction of this antenna is also required. In this work, a concept of optical beamforming (Riza & Thompson, 1997) is implemented to provide a squint-free beam over the entire Ku-band for all the desired pointing directions. The optical beamformer itself consists of continuously tunable optical delay lines that enable seamless tunability of the beam pointing direction

A Coupled Cavity Micro Fluidic Dye Ring Laser

We present a laterally emitting, coupled cavity micro fluidic dye ring laser, suitable for integration into lab-on-a-chip micro systems. The micro-fluidic laser has been successfully designed, fabricated, characterized and modelled. The resonator is formed by a micro-fluidic channel bounded by two isosceles triangle mirrors. The micro-fluidic laser structure is defined using photo lithography in 10 microns thick SU-8 polymer on a glass substrate. The micro fluidic channel is sealed by a glass lid, using PMMA adhesive bonding. The laser is characterized using the laser dye Rhodamine 6G dissolved in ethanol or ethylene glycol as the active gain medium, which is pumped through the micro-fluidic channel and laser resonator. The dye laser is optically pumped normal to the chip plane at 532 nm by a pulsed, frequency doubled Nd:YAG laser and lasing is observed with a threshold pump pulse energy flux of around 55 micro-Joule/square-milimeter. The lasing is multi-mode, and the laser has switchable output coupling into an integrated polymer planar waveguide. Tuning of the lasing wavelength is feasible by changing the dye/solvent properties.Comment: Accepted for Microelectronic Engineerin

Architectures for ku-band broadband airborne satellite communication antennas

This paper describes different architectures for a broadband antenna for satellite communication on aircraft. The antenna is a steerable (conformal) phased array antenna in Ku-band (receive-only). First the requirements for such a system are addressed. Subsequently a number of potential architectures are discussed in detail: a) an architecture with only optical true time delays, b) an architecture with optical phase shifters and optical true time delays and c) an architecture with optical true time delays and RF phase\ud shifters (or RF true time delays). The last two architectures use sub-arrays to reduce complexity of the antenna system. The advantages and disadvantages of the different architectures are evaluated and an optimal architecture is selected

Conformal phased array with beam forming for airborne satellite communication

For enhanced communication on board of aircraft novel antenna systems with broadband satellite-based capabilities are required. The installation of such systems on board of aircraft requires the development of a very low-profile aircraft antenna, which can point to satellites anywhere in the upper hemisphere. To this end, phased array antennas which are conformal to the aircraft fuselage are attractive. In this paper two key aspects of conformal phased array antenna arrays are addressed: the development of a broadband Ku-band antenna and the beam synthesis for conformal array antennas. The antenna elements of the conformal array are stacked patch antennas with dual linear polarization which have sufficient bandwidth. For beam forming synthesis a method based on a truncated Singular Value Decomposition is proposed

Hydroxylation and glycosylation of Δ9-tetrahydrocannabinol by Catharanthus roseus cell suspension culture

Δ9-tetrahydrocannabinol is the active constituent in Cannabis sativa, with reported analgesic, anti-emetic, anti-oxidative, neuroprotective, and anti-inflammatory activities. Δ9-THC has been used to treat a number of disease states including pain, anxiety, asthma, glaucoma, and hypertension. Poor water solubility of Δ9-THC greatly reduces its clinical effectiveness. Consequently, there is a need to modify the compound to increase its polarity and pharmaceutical efficacy. The aim of this study was to test the capability of Catharanthus roseus suspension cultured cells to convert Δ9-THC into more polar derivatives. The transformed metabolites were analyzed and isolated by HPLC. Structures of some new derivatives were proposed on the basis of molecular ion peaks and fragmentation patterns obtained from LC-MS and UV spectra obtained by HPLC, respectively. Δ9-THC was rapidly absorbed by Catharanthus roseus cultured cells and upon biotransformation new glycosylated and hydroxylated derivatives were isolated by preparative HPLC. In addition, cannabinol was detected as degradation product, including its glycosylated derivative. Based on these results, it is concluded that Catharanthus cultured cells have great potential to transform Δ9-THC into more polar derivatives and can be used for the large scale production of new cannabinoids, which can be a source of new compounds with interesting pharmacological profiles