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We present new measurements of Mars at 1.25 and 2mm of wavelength, in addition to the previous ones performed on Mercury and already published in our paper “The brightness temperature of Mercury at 150 and 240GHz”. A brief description of the observational strategy is given, and brightness temperature of the planet is reported.

A double channel (1.2 and 2 mm) photometer has been installed at the focus of the 15m SEST antenna in Chile to perform measurements of the Sunyaev-Zeldovich effect towards X-ray ROSAT clusters. This paper describes the instrument and the characteristics of the system: its sensitivity, field of view, noise and the performed calibrations.

Changes in production and in physico-chemical properties of bronchial mucus is a common denominator of many pulmonary diseases. A rheometer with innovative features aimed at bronchial mucus routine investigation in clinical practice at the bedside of the patient has been designed. Searle-type configuration with a coaxial cylinder sensor system and the Mooney-Ewart geometry has been adopted. Another new feature is that bob and cup are disposable. Dynamic viscoelasticity is calculated through a microprocessor with specific software and by means of a magnetic torque--motor electronically driven by the microprocessor. The self-zeroing procedure and the autorange greatly simplify the measuring-cycle which is driven by only one switch. Data (eta and G') are automatically printed on paper. The whole measuring-cycle at the bedside of the patient takes 3-5 min, so that in 1h about 12 samples can be investigated.

The possibilities of ground based infrared astronomy are discussed. It is shown that telescopes used up to now are not optimized and that the Diffraction Limited Detectivity conditions (DLD) cannot be reached, in the near infrared, by the larger telescopes. The maximum useful diameters for near i.r. and far i.r. telescopes have been evaluated and a new parameter (i.e. visibility) is introduced in order to describe the performances of i.r. ground based telescopes.

The fluctuations in the stratospheric emission in the 800–2000 μm wavelength range have been studied by means of a special correlator operating at 0.3 K. The observed noise is about three times larger than expected from a grey body at a temperature of 250 K and an emissivity of 5 × 10−4. This fact has been interpreted as proof that about 2% of the stratospheric lines were saturated.

We have described an instrument intended to measure the atmospheric transmission through the windows between 300 and 3000 μm. The radiometer operates automatically, scanning the sky in steps of 0.7° from the horizon to the zenith, with the time constant as selected by the operator. The spectral distribution of the radiation is measured using a Michelson interferometer with an optical path difference of ± 10 cm. Using a 77°K reference blackbody, the atmospheric transmission can be measured with an accuracy better than 1 per cent. Some preliminary results are described, obtained at the Alpine station of Testa Grigia (3500 m above sea level).

Different kinds of far i.r. bolometers are compared between 100 and 5 cm−1 in various optical arrangements. A Golay cell has been used as reference detector. The germanium bolometer seems to be about ten-times more sensitive than the other two detectors, while the carbon bolometer shows the highest responsivity.

We describe the design, operation and performances of a FIR photometer suitable for ground-based and balloon-borne astronomical observations in the millimetric and submillimetric regions.

A description is given of a photometer which is suitable for astronomical observations through millimetric atmospheric windows. It consists of a Ge-Ga bolometer operating at 1.0 K, with a throughput AW = 0.3 cm2 sr and a NET = 1 mK Hz-1/2. Two metallic mesh filters set the windows at about 10 and 5 cm-1.

During a balloon borne experiment intended to study the state of polarization of the far infrared radiation in the 100–2000 micron range, a signal was detected from the Sun corresponding to a linear polarization of at least 6,4 % assuming a constant polarization over the whole infrared bandwidth observed (wavelengths longer than 500 microns cannot contribute significantly to the observed signal even if they are completely polarized). The vibrational plane is parallel to the Sun equator within 5°.

Infrared carbon bolometer detectors operating at liquid helium temperature (LHT) have been constructed. The properties of carbon bolometers which depend upon the thickness of the elements have been investigated, particularly with respect to their responsivity. Responsivities up to 106 V/W may be obtained by decreasing the thickness of the element, without any appreciable loss in the far infrared absorption. By using evaporated gold contacts, a NEP lower than 10−12 W/Hz 1 2 has been obtained in two cases. In practice carbon bolometers appear to be competitive with other liquid helium cooled bolometers.

We have measured the temperature of the Sun in the 300–1000 μm region through the atmospheric windows at the high altitude observatory of Testa Grigia, Italy. 3500 m a.s.l. The far i.r. detector used in this experiment is a 150cm flux collector with a germanium bolometer. A set of interferential filters coupled to a specially designed radiometer allow us to isolate and measure the atmospheric windows transmittance with a precision of 1 per cent. The results obtained are in agreement with the HSRA model of the Sun.

Interference filters adequate to isolate the atmospheric windows in the 30-5 cm −1 spectral region are described. The filters have a half-bandwidth of about 2 cm −1 and, with suitable blocking, a rejection factor larger than 10 8 is obtained up to the visible region.

A method using an oxyacetylene torch flame is described; it makes it possible to obtain easily and rapidly, without skill or special equipment, a tungsten micro-electrode tip in a very few seconds.

We have evaluated the accuracy in maintaining the differential modulation parallel to the horizon, which is required to reduce the atmospheric background below the detector noise in an infrared telescope operating under optimized conditions.

A photopolarimeter has been designed to measure the possible polarization of the Cosmic Background Radiation at millimeter wavelengths. The instrument and the working principle are described together with the testing procedure.

During a balloon flight at 45km altitude, we found a quadrupole-like anisotropy in the stratospheric emission in the FIR, aligned in the North-South direction with a typical amplitude of 3×10 −2 K. A sudden increase in the amplitude of the anisotropy was found with a time scale of 1 hr and the amplitude was found to be wavelength dependent (0.25 K at 100 μm and 0.15 K at 600 μm wavelength). This is consistent with an anisotropy in the water-vapour distribution of the order of 5%.

Fluorogold, a glass-filled teflon, is widely used as a long-wave pass filter in the infrared. We have found an important intrinsic polarization arising from the scattering of the radiation by the aligned grains of the reinforcing aggregate bound by teflon. The effect must be taken into account in the case of Fluorogold filters employed with a polarizing Michelson interferometer for measurements of absolute fluxes, as in the course of observations of the cosmic background spectrum carried out by several authors.

The modern optical microscopic technique together with the use of the small perfusion chamber allows the maintenance and observation of isolated ciliated epithelia for many hours in vitro. Counting ciliary beats is a good means for evaluating the behavior of these cells immediately under different environmental conditions and also for evaluating the pharmacologic or toxic action of drugs. Using a TV camera joined to a microscope equipped with the Nomarsky differential interference contrast set, it is possible to see on a TV monitor an image of the cilia at a very high magnification (over 1000 ×), with a good resolution. This paper describes a method and an instrument, with a digital readout purposely designed to receive and count signals from a phototransistor placed directly on the protective screen of the TV monitor to correspond exactly with the point of passage of the coming and going movement of the selected cilia. In this way, it is possible to obtain (in real time and in a simple way through visual observation of the beat) the final count, which consists of the number of passages, in a prefixed time, in front of the phototransistors of the dark area which represents the ciliary body on the light background.

Recently large voids in galaxy distribution have been found by means of red shift surveys. We consider the possible effect of the presence of one of these voids (the one found by Kirshner et al. (1982) in Bootis) on the cosmic microwave background photons.

Polyethylene embedded with glass microspheres has shown the same optical properties as Fluorogold™ in the far-infrared. The polarizing properties of Fluorogold (laminated in thin foils) are avoided by pressing the polyethylene/glass powder between hot plates. The new fiters are suitable for long-wave pass filters with intrinsic polarization less than 10−4