Manuel C. Lagunas-Solar

Method of controlling microorganisms by pulsed ultraviolet laser radiation

Microorganisms, including not only bacteria related to hygiene, food spoilage and human pathogenesis but also fungi which are commonly found in fresh fruits and vegetables, can be reduced or eliminated for surface microbial disinfection of foods and for other purposes by exposing an area containing such microorganisms to a monochromatic beam of pulsed ultraviolet laser radiation of wavelength about 240-280 nm, or in particular about 240-260 nm, with pulse duration in the range of picoseconds to microseconds at 1-1900 mJ/cm2 for most situations. Laser energy irradiance should be controlled in the case of some foods because of the limited tolerance to such exposure.

Continuous flow radioactive production

A method is provided for preparing medicinally acceptable 123 I by bombarding an XI (X is alkali metal or I) target in the liquid phase with a proton beam of a predetermined amperage and energy, while continuously passing a helium stream, optionally having a small amount of xenon, through the target area. The radioactive xenon collected by the helium stream is trapped in a cold trap, purified and then isolated in a deacy vessel, where the xenon decays to 123 I. An iodine scavenger is provided for the helium effluent from the target, to remove any iodine from the helium stream, which would decrease the purity of the desired isotope.