Treatment of Cs liquid wastes by reverse osmosis Part I. Preliminary tests

As a consequence of an accidental fusion of a ¹³⁷Cs source in a steel production factory, 40 m³ of radioactive liquids were generated in the plant decontamination process. This radioactive liquid waste was treated by a reverse osmosis plant, managing to declassify more than 36 m³. The remaining 4 m³ were treated by evaporation reducing the final volume to less than 1 m³. Prior to the waste treatment at the steel factory, preliminary tests were done in order to determine reverse osmosis membrane performance with ¹³⁷Cs effluents. The influence ofgamma and electron irradiation on structure and transport properties of reverse osmosis membranes was studied; and reverse osmosis performance with a ¹³⁷Cs-contaminated liquid obtained from contaminated ashes was assessed. The aim of this paper is to describe and show the results of these preliminary tests.     

Compact Waveguide-Based Power Divider Feeding Independently Any Number of Coaxial Lines

The device described in this paper has been designed to enable the feeding of many individual plasma sources from a single microwave generator, providing a noninterfering and constant supply of power to each coaxial line driving these plasma sources. The power coming from the generator flows through a waveguide under standing-wave conditions provided by the presence of a conducting plane located at the waveguide end opposite that linked to the generator. Power is extracted from the waveguide, at the maximum of intensity of the E-field standing wave, by a waveguide-to-coaxial-line transition designated as a probe. One or two probes can be set at each such maximum of field intensity (and this on both sides of the waveguide wide wall), yielding a compact power divider. Each coaxial line feeds a microwave field applicator, sustaining plasma, through a matching circuit comprising a tuning means and a ferrite isolator (circulator with a matched load), the latter ensuring that whatever happens to the plasma source, the other feeding lines are not affected. The conditions required for a perfect match of the microwave generator to the power divider are elaborated and examples of actual designs are presented     

Effect of controlled atmospheres on maintaining quality of persimmon fruit cv. "Rojo Brillante"

ABSTRACT:  Astringent "Rojo Brillante" persimmon fruits were stored in air or in 2 different controlled atmospheres: 10% CO₂+ 90% N₂ (CA1) or 97 % N₂+ air (CA2) for up 50 d at 15 °C. After different periods, the fruit were treated with 95% CO₂ for 24 h at 20 °C in order to remove astringency, and then transferred to 20 °C in air free of CO₂ for 5 d to simulate shelf life. Other fruits were directly transferred to shelf life without being submitted to deastringency treatment. Storage under CA2 allowed storability of persimmon "Rojo Brillante" during 30 d at 15 °C, maintaining commercial firmness. Moreover, CA2 had an effect on removing astringency when fruits were stored for 30 d at 15 °C, or after 20 d following to shelf life. As consequence, deastringency treatment could be avoided when the fruits were previously stored under this controlled atmosphere.     

Remise en etat des carrieres

The application of the law on Environment, states in article n^o 24 that a quarry's site must be restored when the extraction is over. This oblitation belongs to the quarry or gravel pit's society, but the use of the site itself belongs to the owner of the ground. The two notions are often the subject of quarrels between quarries' societies and groups taking the protection of Nature into account, because they are not always correctly separated. The “Ponts et Chaussées” Laboratories have included this problem in their action of technical support to the stone industry. Three notes have been written pointing out the main topics that must be included in a restoration study after extraction, to allow the owner to make afterwards, the best use of the site at the lowest cost possible. These notes concern 3 cases:

-The use of ancient quarries' sites for sport or open air activities.

-The restitution of the site to its natural context.

-The use of the site for agriculture.

     

Successive self-nucleation/annealing (SSA): A novel technique to study molecular segregation during crystallization

A new procedure to fractionate ethylene/α-olefin copolymers using DSC is presented. This procedure allows melt/melt and melt/solid segregation to occur during thermal cycles that promote self-nucleation, crystallization and annealing processes (Successive Self-Nucleation/Annealing, SSA). The SSA has been compared with the Step-Crystallization (SC) method proposed earlier in the literature to qualitatively characterize chain branching distribution in a faster and easier way than Temperature Rising Elution Fractionation (TREF). In general, SSA produces better fractionation than SC and the DSC derived chain branching distribution by SSA can be qualitatively comparable to that obtained by TREF. The SSA technique could have important applications for the characterization of polymers that crystallize over a broad temperature range. Received: 10 May 1997/Revised: 20 July 1997/Accepted: 6 August 1997     

Correlation between the morphology of cobalt oxalate precursors and the microstructure of metal cobalt powders and compacts

Metal cobalt powders of well-controlled size and morphology were synthesized by thermal decomposition under hydrogen of precipitated cobalt oxalates. Green compacts were prepared by uniaxial pressing of metal powders at 290 MPa. The bending green strength of the metal compacts was measured.A precipitation from ammonium oxalate and oxalic acid gives rise to the formation of β-CoC₂O₄·2H₂O particles of parallelepipedic and acicular morphology, respectively. An increase in the length to diameter ratio of the precursor particles favours an entanglement of the elementary grains during the thermal decomposition. Therefore, irregular and rough metal particles have been obtained. This specific morphology favours a mechanical interlocking of the particles during the compaction, leading to high values of green density and green strength of the metal compacts.     

WHITE ASPARAGUS HARVEST DATE DISCRIMINATION USING NIRS TECHNOLOGY

Asparagus is still an important resource for mid-size and small farms. It has been traditionally believed that factors such as the asparagus harvesting date have an influence on its quality. This research sought to identify the harvesting dates of different fruits by using Near Infrared Spectroscopy (NIRS) technology as quality indicators and the best zone a long of the asparagus to acquire the spectrum. All the asparagus tested came from the same manufacturer but had been canned on three different dates, giving a total of nine lots. There were one hundred asparagus per lot and the experiment data were taken from three different parts (tip, middle, and base) of each spear. Reflectance spectrum in the near infrared between 800–1700 nm was determined. Differences NIRS among the asparagus harvested on different dates were found. NIRS technology was able to classify the asparagus correctly in terms of harvest dates (71% well classified). The base of the asparagus turned out to be the best part to use in order to establish the harvest date.     

The evaluation of the state of dispersion in immiscible blends where the minor phase exhibits fractionated crystallization

Summary Differential Scanning Calorimetry (DSC) can provide a qualitative measure of the state of dispersion of an immiscible blend if the minor phase exhibits fractionated crystallization when dispersed into fine particles. The technique is only sensitive to the volume of the dispersed particle and not to its shape and can only be used when the exotherms of interest do not overlap with other thermal transitions present in the multicomponent system. Selfnucleation is a valuable tool to ascertain the presence of fractionated crystallization. The morphology induced by fractionated crystallization in immiscible blends could lead to enhanced plastic deformation during yielding of the matrix.