ABSTRACT
We describe a balloonborne telescope devoted to millimeter observations of diffuse sky radiation and optimized with a custom set of baffles and shields. The basic idea of the shield design is to shape the surfaces as roof mirrors to redirect the stray radiation in the opposite direction of incidence. The baffles are used to stop radiation close to the field of view. In this way we are able to avoid most of the unwanted radiation. We successfully operated this telescope (ARGO) during two flights, in 1989 and 1993, while detecting the faint structures of the cosmic microwave background at degree scale.
ABSTRACT
The Millimetre and Infrared Testa Grigia Observatory 2.6-m Cassegrain telescope has been designed to allow high-sensitivity observations in the millimeter spectral range. For this purpose, in order to reduce unwanted contributions from local foregrounds, we adopted a sky-chopping technique, by wobbling the telescope subreflector. We describe the design and performance of the wobbling system, which can endure external forced two and three fields square-wave modulation and includes features such as high frequency, high amplitude, high duty cycle, low microphonics, and high stability.
ABSTRACT
The optical design of two Cassegrain-type telescopes of 1200- and 2500-mm primary mirrors has been studied by wobbling subreflectors to obtain differential measurements in wavelengths ranging from 300 microm to 2 mm of the spectrum. Wide chopping angles in the sky have been reached in spite of the large apertures and high secondary magnifications. Diffraction-limited performances are maintained by tilting the secondary mirror around the primary focus. This work is included in the TIR (Telescopio InfraRosso) project.
ABSTRACT
The interaction of jatrophone with sRNA from Escherichia coli has been investigated through UV, CD, and 1H NMR measurements. The results obtained show that the interaction with jatrophone increases the stability of the polynucleotide. It appears that the optical properties of jatrophone depend upon the jatrophone/nucleotide ratio. The observed behaviour can only be explained by the existence of different types of interaction between jatrophone and sRNA. Even for a jatrophone/nucleotide ratio as low as 0.17 the 1H NMR spectra show a multiplicity of resonances that can only be explained by the simultaneous existence of two different binding modes involving the jatrophone molecules.
