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O T Ogunleye

Publications and source records attributed to O T Ogunleye.

9 recordsLinked to original sources
PubMed1985

A proposed modification of the cavity theory for electrons.

An empirical expression of cavity theory for electron fields is developed in a fashion similar to Burlin's general theory of cavity ionization for photons. It incorporates a term that relates the absorbed dose ratio in the cavity and material medium to the differences in electron scattering. This new expression correlates very well with experimental observations for progressively increasing LiF cavity sizes embedded in different media, the energy response of LiF at high electron energies relative to 60Co and the absorbed dose conversion factors CE in the ionization chamber dosimetry of electron beams.

Electrons↗
PubMed1980

Comparison of Burlin cavity theory with LiF TLD measurements for cobalt-60 gamma rays.

Cobalt-60 gamma-ray absorbed dose measurements were carried out using LiF thermoluminescent (TL) dosemeters to obtain additional insight into cavity theory as applied to dosemeters of a size intermediate relative to the range of secondary electrons. Stacks of dosemeters (0.4 mm x 3 mm x 3 mm, hot-pressed LiF TLD-100) were surrounded by homogeneous LiF, polystyrene, aluminium, copper or lead. The absorbed dose in the stack (0.1 to 0.7 g cm-2 thick) was derived from TL readings of the individual dosemeters, and was compared with calculations based on the Burlin cavity theory. A relatively strong asymmetry in the experimental absorbed-dose distribution was found between the front, rear and middle dosemeters of the stack, especially when lead was the surrounding medium. Cavity theory shows good agreement with the experimental results obtained in polystyrene, while theory tends to overestimate the dose in the LiF dosemeters enclosed in Al, Cu, and Pb. The general trend predicted by the Burlin theory is somewhat steeper relative to cavity size than that observed experimentally. The theory was modified to make it more applicable to the dose at the centre of the stack. For lead this clearly agreed more closely with experimental results than did the conventional theory.

Cobalt Radioisotopes↗
PubMedDate not supplied

Radiation accidents in a developing country: the Nigerian experience.

A 32 year old Nigerian industrial radiographer was accidentally over-exposed to gamma rays while using a faulty gamma ray equipment with an iridium 192 source to take radiographs of oil pipe joints for the detection of cracks. He presented with clinical signs and symptoms of radiation over-exposure. When results of personnel monitoring confirmed radiation over-exposure this patient was immediately relieved of his job by his employers without any explanation or compensation. His condition was managed conservatively and he is being followed up indefinitely in the clinic. This paper as well discusses the management of acute radiation syndromes and the implications of the presently uncontrolled use of ionizing radiation in Nigeria.

Accidents, Occupational↗