A method and apparatus for monitoring the level of tritiated water vapor in air using a solid scintillator.

Tritium is presently used in large quantities in laboratories for technological studies, as fuel for the process of nuclear fusion, and in the manufacture of radio-luminescent items. It is also produced in fission nuclear plants (with a yield of 10(-4) if the fuel is 235U and twice as much if the fuel is 239Pu), particularly in those which use D2O as moderator. The weak energy of beta particles (Emean=5.

A gas scintillation monitor for tritium gas in argon or in nitrogen.

For civilian purposes tritium is presently used in quantities of tens of PBq (MCi) in laboratories for the studies of tritium technology, at the Joint European Torus plant (Abingdon, Oxon, OX143A, UK) as fuel for the process of nuclear fusion, and in the manufacture of radio-luminescent items. Given the extreme mobility of tritium in most materials, it is necessary to use systems for double containment, such as glove boxes or spaces between primary and secondary containers, in which inert gas like argon or nitrogen flows. With these systems it is possible to recover tritium that escapes from the primary containment.

Scintigraphic recording of blood volume shifts.

Unlabelled: A scintigraphic device consisting of small scintillation probes tightly fixed to the skin was developed to record intravascular blood volume shifts continuously and simultaneously at several sites. The aim of the present study was to ascertain the reliability of the measurements obtained, show the blood shifts induced by common daily activities in healthy subjects and clarify the mechanisms responsible for hemodynamic changes.

Methods: Measurements were made in three fields of the right lung, the liver, thighs and calves of 16 men during Valsalva maneuver, hyperventilation, various posture changes and treadmill walking.

Gastric emptying of radionuclide-labeled solid meal in beagle dogs using a scintigraphic method.

A scintigraphic method for in vivo radiotracers measurement is described to investigate the gastrointestinal emptying rate in beagle dogs. The proposed method has been applied to study the effect of a pharmacological compound in enhancing stomach emptying and involves the following steps: 1) 131I-labeled anion exchange resin grains preparation, as solid food markers to be ingested by the dogs; 2) continuous recording of gastric emptying evolution over a period of 5 h with fast data-gathering instrumentation employing small size and light-weight CsI scintillation detectors coupled to a photodiode, equipped with a lead shield and collimator; 3) comparison of results obtained with drugs to previous standard emptying curves. The purpose of this study was to evaluate the prokinetic activity of a recent synthesized compound (BIMU 1).

Simultaneous recording of blood volume shifts in different vascular beds in man by a versatile scintigraphic method.

A device was developed to record the blood volume changes occurring in the lung and calf during postural changes, physical exercise, and the Valsalva maneuver in man. The changes in regional counting rates from the right middle lung and the calf mirrored the well-known changes in venous return that are expected to occur in response to the above-mentioned external stimuli. Thus a sustained decrease in lung blood volume was noted on assumption of the erect posture as well as during the forced expiration of the Valsalva maneuver.