Background: An effective method for management of large and bulky malignant tumors. This treatment modality is also known as Specially Fractionated Radiation Therapy (SFRT). In this treatment technique a grid block converted the open radiation field into a series of pencil beams. Dosimetric characteristics of an external beam grid radiation field have been investigated using experimental and Mo...

Introduction Radiotherapy planning systems require many percentage depth dose (PDD) and profile measurements and there are various dosimeters that can be used to obtain these scans. As dose perturbation is particularly troublesome in smaller photon fields, using a low-perturbation, unshielded electron field diode (EFD) in these fields is of interest. The aim of this work was to investigate the ...

This study determined whether the field level concentration of root zone CO2 affects transpiration rate and root water transport in soybean (Glycine max L. Merr.). In an upland field converted from a paddy field, topsoil CO2 during the cropping season rose to 8 kPa of partial pressure after rainfall, whereas O2 dropped only to a minimum of 7 kPa. An elevated root zone CO2 pressure of 6 kPa sign...

Transpiration is frequently measured by enclosing plants, or portions of plants, in transparent chambers and determining the change of humidity of a stream of air before and after passing through the enclosure (2, 4). Although this procedure should not be used to estimate probable transpiration rates under natural conditions, unless adequate precautions are taken to ensure that the microenviron...

Background: The accuracy and the reproducibility of radiotherapy can be provided by using immobilization devices such as thermoplastic masks. In head and neck cancer radiotherapy, the patients are mostly immobilized by using thermoplastic masks. In this study, the effect of the thermoplastic mask to the surface and buildup region doses was investigated by using Markus parallel plate ion chamber...

expansion of apple growing to dry areas requires reliable approaches to select genotypes tolerant to water stress. we have simulated apple tree transpiration (ec) from different commercial orchards and compared it with actual transpiration (ea) derived from sap flow measurements. the modelling approach lies in rearranging a parameterized p–m equation and incorporating in it a stomatal conductan...