An indwelling drainage system for percutaneous drainage and radiotherapy of cystic craniopharyngiomas is described. The catheter is implanted into the cyst stereotaxically with a computed tomography-guided targeting device and connected to a Rickham reservoir. In addition to the repeated percutaneous evacuation of the cysts, this closed system enables intracavitary radiotherapy (yttrium-90) wit...

Some of the highest losses of nitrate to surface waters come from drained agricultural land. Given previous this article studied for Belgian farming conditions (i) the effect of subsurface drainage density on nitrate losses and (ii) the economics of nitrate emissions, using the nitrogen version of DRAINMOD (Brevé et al., 1997 a and b). DRAINMOD (Skaggs, 1997) was used to simulate the performanc...

In the South African sugar industry it is important that relatively inexpensive but viable drainage systems are de,:el,oped for those soils which have a low hydraulic conductrvity. From the results offield and laboratory investigations conducted during the past five years it appears that the use of unlined mole channels as an alternative for, or a supplement to conventional subsurface drainage,...

This computational study analyzes how to design a drainage system for porous scaffolds so that the scaffolds can be vascularized and perfused without collapse of the vessel lumens. We postulate that vascular transmural pressure--the difference between lumenal and interstitial pressures--must exceed a threshold value to avoid collapse. Model geometries consisted of hexagonal arrays of open chann...