Showing papers by "National Nuclear Energy Commission published in 1982"

Studies on the chemical constitution and sex pheromone activity of volatile substances emitted byDacus oleae

Abstract: Volatile substances from the females ofDacus oleae have been submitted to GLC-MS analysis and several components identified. E-6-nonen-1-ol and p-cymene displayed attractive and aphrodisiac effects in both laboratory and field experiments.

The electrochemical potentiokinetic reactivation method--an analysis of different treatments of experimental data

Abstract: Two heats of Alloy 800 have been tested by the Strauss (ASTM A 262 Practice E) and the electrochemical potentiokinetic reactivation (EPR) methods to detect the tendency to inter-granular corrosion. Different treatments of the EPR data have been studied. The best criterion appears to be the calculation of the normalized reactivation charge, Pa, and its representation as time function and in TTS-coordinates. The comparison between the sensitivity of both tests revealed the higher sensitivity of the EPR test for the lower degrees of sensitization (DOS) and its saturation for the higher DOS.

The Plasma Focus

Abstract: The name Plasma Focus (PF) has been bestowed upon a development of the fast dynamic Z-pinch characterized by a new type of electrode configuration which lends itself to the production of a non-cylindrical implosion of the current sheath. It produces a short lived, rather dense plasma, whose properties are dominated by the occurrence of macroscopic and microscopic instabilities. The fame of the PF has long been based essentially on the fact that it was the most intense neutron producing device in the field of controlled thermonuclear research. Moreover, the neutron yield has the remarkable property of scaling as the second power of the energy W o stored in the capacitor bank. The question of the character of the neutron spectra of the PF correlated to the neutron production mechanism, has long cast fundamental doubts on the relevance and interest of developing further this line of research for applications in the field of controlled fusion.

Photoreactivating enzyme induction in human lymphocytes

Abstract: — Photoreactivating enzyme (PRE) activity was determined in human lymphocytes cultured in the presence or absence of the mitogen phytohemagglutinin (PHA). Photoreactivating enzyme activity increased from 0 to 12pmol/mg/h in about 40 h in cells cultured in the presence of PHA; enzyme activity was unchanged in the absence of PHA. The kinetics of induction of PRE and of lactate dehydrogenase, a marker of mitogenic stimulation, were indistinguishable, indicating that PRE induction results from stimulation of transcription and translation by the mitogen, rather than a specific effect of the PHA on PRE production. The level of PRE was also higher in mouse lymphoblasts growing rapidly in RPMI 1640 medium than in the same cells growing more slowly in Dulbecco's medium.

239+240Pu and 238Pu in seawater, marine organisms and sediments of Taranto Gulf (Ionian Sea)

Abstract: Results of the radiochemical determination of 239+240 Pu and 238 Pu in seawater, plankton, marine organisms and sediment are reported. The samples were collected in the Taranto Gulf, and the data are compared with those obtained from other stations in the Mediterranean Sea. The vertical distribution of plutonium isotopes in sediments is also presented and discussed.

Single longitudinal and transverse mode operation of a hybrid unstable resonator TE CO2 laser

Abstract: Single-mode operation of an atmospheric-pressure TE CO2 laser is reported. Single longitudinal mode emission has been achieved by incorporating a low-pressure, transversely excited gain section in the same laser cavity as the atmospheric-pressure section. The effects of different resonator configurations on the system modal behaviour have been investigated and it is shown that unstable resonators are particularly suitable for controlling the transverse mode structure with a complete coverage of the excited medium. With an unstable resonator configuration, formed by a metallic convex mirror and a plane diffraction grating, single longitudinal and single transverse mode output pulses with energy up to 2 J have been produced on more than 40 lines of both the 9.4μ m and 10.4μ m bands. This technique can easily be scaled to larger aperture devices at higher extracted energies.

Preliminary Observations of The Strain-Induced Corrosion of Alloy-800 in Sodium Hydroxide-Saturated Sodium and on its Evolution in Dynamic Purified Sodium

Abstract: Incoloy-800 of specially controlled composition and micro- structure has been selected for the steam generators of sodium cooled fast breeder reactors (1,2). The assessments involved in such a selection were found to meet all the design requirements, including the corrosion resistance in normal service conditions or abnormal conditions (thermovector fluids contamined by sodium-water reaction products) (1).

Modelling for The Carburization of The Alloy - 800 in Liquid Sodium

Abstract: The interstitial carbon transfer is one of the most important phenomena concerning the compatibility of metals and alloys with high temperature liquid sodium. In previous comunications we reported some methods to evaluate the extent of the carburization (or decarburization) expected to occur on austenitic steels exposed in a given sodium environment (1, 2). The calculations were essentially based on the criteria developed by Snyder, Natesan and Kassner (3) for the AISI 304 and 316 steels, but some simplifications and minor modifications were introduced to take into account the empirical model performed by Shrock, Shiels and Bagnall (4, 1) and of the coupling of the interstitial carbon diffusion with the selective leaching of the Cr and Ni substitutional alloying elements acting on the same time at the surface of the materials exposed in the hotter zone of the sodium loops (2).

Plasma heating in the ignitor device

Abstract: The main features of the IGNITOR device are presented. Two kinds of heating cycles are considered. The first consists of a combination of ohmic heating and adiabatic compression. The second, in addition, includes LH auxiliary heating in the discharge phase preceding compression. It is shown that in both cases plasmas of thermonuclear interest can be obtained, suitable for the study of phenomena related to α-particle heating.

Milan-2, A Software Tool for System Identification By Imbedding

Abstract: The here illustrated software tool comprises a language the principal aim of which is to facilitate the application of imbedding to system identification through the use of multiple integration mec...

The radially symmetrical model in defining the diffusion coefficient: An application to the bay of La Maddalena Island

Abstract: The general procedure of application of the radially symmetrical method for the evaluation of the turbulent diffusion coefficient is presented. This allows a discussion on the method and its practical application.

Caburization Kinetics of All0y-800 in Liquid Sodium at 550 °C

Abstract: The austenitic Alloy-800 steel is a structural material candidate for the steam generators of nuclear power plants, including the sodium cooled breeder reactors (1). In this case the Alloy-800 is exposed to the sodium environment of the secondary heat transfer system coupled to the AISI type 316 or 304 stainless steels generally employed for the intermediate heat exchanger components. For this all-austenitic bimetallic system the corrosion of the materials and the consequent mass transfer are not of relevant importance in the normal service conditions (good technological purity of the sodium and temperatures below 550 °C). However a certain carbon (or nitrogen) interstitial transfer may occur because of the thermal gradients and the different nature of the alloys of the loop; a general carburization could also arise because of the presence of possible carbon sources during the plant running (2).

The Particulates in the Atmosphere and their Intrapulmonary Deposition

Abstract: The respiratory tract is, of the body structures, one of the most exposed to environmental agents, in view of the extremely high surface area and of the air volume which is exchanged daily.