Progress in ultrasonic bioreactors for CELSS applications.

An important issue in Controlled Ecological Life Support Systems (CELSS) is the recycling of inedible crop residues to recover inorganic plant nutrients such as nitrates, phosphates, potassium and other macro- and micro-nutrients. In a closed system in space, such regeneration is vital to the long term viability of plant growth necessary for the food production and waste handling process. Chemical approaches to recycling such as incineration and wet oxidation are not compatible with low energy and environmentally friendly regeneration of such nutrients. Biological regeneration is more acceptable environmentally, but it is a very slow process and does not typically result in complete recovery of inorganic and organic nutrients. A new approach to biological regeneration is described here involving the combined use of special enzymatic catalysts and ultrasonic energy in a bioreactor system. This new system has the potential for rapid, efficient, environmentally friendly and complete conversion of crop wastes to inorganic plant nutrients and food recovery from cellulose materials. A series of experimental tests were carried out with a soybean crop residue meal substrate. Biochemical conversion rates were significantly expedited with the addition of enzymes and further enhanced through ultrasonic stimulation of these enzymes. The difference in conversion rates was particularly increased after the initial period of soluble organics conversion. The remaining cellulose substrate is much more difficult to biodegrade, and the ultrasonically-enhanced reaction was able to demonstrate a much higher rate of substrate conversion.     

Statistical method for ground and sky coverage calculation

A novel statistical method has been devised for evaluating the ground and the sky coverage of an observation experiment on board a satellite. Owing to its unrivalled rapidity compared with other conventional calculation techniques, the method can be applied to evaluate the coverage percentages for the whole globe or any area on it, to calculate the visibility percentages for one or more ground stations and to determine the percentages of observation time of any given celestial direction including Sun, Moon, Earth and Ground Stations constraints. The orbits considered can be elliptical and account is taken of the drift due to the Earth's oblateness.     

Soft X-ray emission from radio Loops I and III compared

We examine X-ray maps of the whole sky covering energies from 0.1 to 6 keV. We model Loop I X-ray emission as being caused by an old supernova that exploded into an already warm interstellar medium. After comparison with Loop III we deduce that there may be a general temperature gradient in the gas as we move away from the plane in the northern galactic hemisphere.     

Mean winds of the mesosphere and lower thermosphere (60–110 km): A global distribution from radar systems (MF,Meteor, VHF)

During the last decade a large number of radars (～12) have been developed, which have produced substantial quantities of tidally-corrected mean winds data. The distribution of the radars is not global, but many areas are well covered: the Americas with Poker Flat (65°N), Saskatoon (52°N), Durham (43°N), Atlanta (34°N), Puerto Rico (18°N); Europe with Kiruna (68°), Garchy (47°N) and Monpazier (44°N); and Oceania with Christchurch (44°S), Adelaide (35°S), Townsville (20°S), and Kyoto (35°N). Zonal and meridional wind height-time cross-sections from $\text{60}\text{80}$ km (MF/Meteor Radar) to ～110 km have been prepared for the last 5–6 years. They are compared with cross-sections from CIRA-72 for zonal winds, and Groves (1969) for meridional winds.It is shown that while CIRA-72 is still a useful model for many purposes, significant differences exist between it and the new radar data. The latter demonstrate important seasonal, latitudinal, longitudinal and hemispheric variations. The new meridional cross-sections are of great value. The common features with Groves (1969) are the equatorward cells in summer near 85 km; however their strength (～10 ms^?1) and size are less. Systematic and somewhat different variations emerge at higher (?52°N) and middle (35–44°) latitudes.     

A new polyethylene balloon film

After over twenty years there is a new film introduced in the United States for fabricating scientific balloons. The film was developed by Raven and is designated Astrofilm.The film is a result of a critical selection of both the resin and extruding parameters. The film's physical properties and results of a test flight are reported. Also reported are a proposed design modification and failure analysis.     

A balloon-borne sun-tracking multichannel photometer for atmospheric aerosol measurements

A balloon borne multichannel photometer for measurement of atmospheric scattering in the near ultraviolet and the visible wavelength regions has been developed at the Physical Research Laboratory, Ahmedabad for study of the size distribution and number density of aerosols at tropospheric and lower stratospheric altitudes. The instrumentation involves tracking the sun in elevation and scanning in azimuth. The payload was recently flown on a 100 kg. balloon from the Hyderabad Balloon Facility on 18 April 1984. The balloon reached a float altitude of 35 km and good quality data has been obtained from an altitude of 6 km upto float altitude. Data analysis is still in progress. The present paper details the instrument design and presents a few illustrations of the instrument performance from this flight.     

Synthetic Environments for Simulated Missions

Synthetic environments offer Space Flight projects an opportunity to perform rapid, comprehensive, and rigorous modeling of the critical elements of a mission in order to compute quantitative measures of design performance, associated risk, and actual mission utility value. Significantly, these studies can be performed early in the mission cycle. These synthetic terrains are generated on parallel, high-performance computers and served to remote simulations at near-interactive speeds. The terrain creation uses a realistic sequence of physical phenomena such as cratering and dusting with parametric control of features such as surface roughness and rock density. Terrain resolution may be arbitrary but typically ranges from 0.01 to 10 meters. The terrain server has been used for two rover simulations, one using the actual Sojourner autonomy flight code, and the other a more general algorithm. Monte Carlo studies of rover designs interacting with synthetic environments were executed in parallel to quickly compute performance statistics and risk estimates.     

An investigation of small GOES flares with intense hard X-ray bursts

Most solar flare observations show that intense hard X-ray bursts come from large flares that have a large GOES classification (large peak 1 – 8 Å flux). This correlation, known as the “Big Flare Syndrome”, suggests that more intense flares tend to have harder spectra. We have observed 7 flares that are exceptions to this. These flares have small GOES classifications ranging from B1.4 to C5.5 and peak hard X-ray count rates similar to those often observed from M class flares. This paper examines the cause of this anomoly using the Yohkoh Soft X-Ray Telescope, Hard X-Ray Telescope, and Bragg Crystal Spectrometer. Two hypotheses are proposed for the exceptions: (1) flares with multiple magnetic loops and common footpoints, producing multiple hard X-ray emission regions and low density thermal plasma distributed over a large volume, and (2) high densities in the magnetic loops restricting the propagation of the non-thermal electrons in the loop after magnetic reconnection has occurred and suppressing chromospheric evaporation. Two of the flares support the first hypothesis. The other flares either have data missing or are too small to be properly analysed by the Yohkoh instruments.     

A low cost steerable radio-telescope

We present the technical characteristics of a low-cost radio telescope for solar/non solar observations at decimetric (1200–1700 MHz) and centimetric (2700 and 5000 MHz) wavelengths known as Brazilian Decimetric Array (BDA). The technical specifications of the antenna, tracking system, log-periodic feed, preamplifier and the frequency-synthesised receiver with a Single Side Band (SSB) video output of 2.5 MHz are given.