Seventeen cases are described in which both atria connect directly to a chamber with right ventricular characteristics. The atria connected through separate atrioventricular valves in six hearts and a common valve in 11. All hearts had a posterior rudimentary chamber. The septum which separated it from the main chamber was directed to the crux of the heart. Ten hearts were from patients with at...

An experimental determination has been made of the perturbation correction to be applied to a graphite cylindrical (thimble type) ionization chamber. The results indicate that the magnitude of this correction increases with depth and is closely related to the size of the cavity. This makes possible the use of such a chamber as an' excellent standard of absorbed dose in graphite for 60Co gamma r...

In this study, a procedure to test the linear reference air kerma rate of 192Ir wires using a well-type chamber is described. The method is based on a special lead insert with a 1 cm acrylic aperture that provides a differential response of the well chamber. The wire is considered divided into 1 cm parts. Using an external positioning system it is possible to place every part of the wire at the...

Univentricular heart of left ventricular type is defined as the condition in which the entirety of atrial inputs is committed to a main chamber exhibiting trabecular pattern of left ventricular type, usually in the presence of another chamber in the ventricular mass which has a right ventricular trabecular pattern. This condition can occur with two atrioventricular valves, a common atrioventric...

Deformation of the material during cyclic expansion extrusion (CEE) is investigated using upper-bound theorem. The analytical approximation of forming loads agrees very well with the FEM results for different amounts of chamber diameter, friction factor and also for lower die angles. However, the difference between analytical and numerical solution increases at higher die angles which are expla...

A long-term comparison was done between the manufacturer-stated ¹⁹²Ir activity and the measured ¹⁹²Ir activities determined with a well-type ionization chamber. Sources for a Nucletron Micro Selectron high-dose-rate (HDR) unit were used for this purpose. The radioactive sources reference activities were determined using a PTW well-type ionization chamber traceable to the National Institute of S...

The work presented focuses on the measurement of Ja e plots and determination of ion recombination factors for plane parallel ionisation chambers used in pulsed electron beams. The ability to measure the Ja e plots accurately is useful when commisioning a new chamber and the ion recombination correction factor needs to be known when the chamber is calibrated in a beam quality di erent from the ...