Multiple-beam groundstation reflector antenna system : a prelimary study

A wide-scanning multiple-beam reflector antenna, two systems are investigated. A bifocal antenna, designed with the use of an existing method, appears to be unsuitable for wide-angle scanning. A dual-reflector offset torus-antenna showed promising results. As an illustration of its benefit, a possible application is examined: the simultaneous reception of signals from a number (n) of geostationary direct broadcast satellites with mutual distance of 6 degrees. Using this antenna yields advantage when compared, with respect to the total required reflector area, with n separate antennas.<br/

Multiple-beam groundstation reflector antenna system : a prelimary study

A wide-scanning multiple-beam reflector antenna, two systems are investigated. A bifocal antenna, designed with the use of an existing method, appears to be unsuitable for wide-angle scanning. A dual-reflector offset torus-antenna showed promising results. As an illustration of its benefit, a possible application is examined: the simultaneous reception of signals from a number (n) of geostationary direct broadcast satellites with mutual distance of 6 degrees. Using this antenna yields advantage when compared, with respect to the total required reflector area, with n separate antennas

The sulfonamide moiety in peptidomimetics and peptidomimetic-peptide hybrids

No abstract available

The sulfonamide moiety in peptidomimetics and peptidomimetic-peptide hybrids

No abstract available

Synthesis and screening of libraries of synthetic tripodal receptor molecules with three different amino acid or peptide arms: identification of iron binders

A novel selectively deprotectable triazacyclophane scaffold was used for the design and split−mix synthesis of two libraries of solid-phase bound tripodal synthetic receptors possessing three different amino acid or peptidic arms. In the synthesis of the first library, the two outer arms consisted of amino acid Ala, Arg, Asp, Gln, Gly, Lys, Phe, Ser, Tyr, or Val and the middle arm consisted of amino acid Asn, Glu, His, Leu, or Pro. The second library contained amino acid and/or (di)peptide arms. The arms were different in all library members. The first outer arm consisted of amino acid(s) Ala, Arg, Gln, Phe, or Ser, the second outer arm consisted of amino acid(s) Asp, Gly, Lys, Tyr, or Val, and the middle arm consisted of amino acid(s) Asn, Glu, His, Leu, or Pro, leading to a 27 000 member library of synthetic tripodal receptor molecules. In on-bead screening experiments, a remarkable selectivity of some library members for Fe3+ was observed and decoding of their structures by Edman degradation revealed consensus sequences with structural resemblance to non-heme iron proteins