RESUMO
Long pulse operational characteristics of the high current ion source for the KSTAR neutral beam system are described. The beam pulse length of 300 s was successfully operated at a beam power of 1.6 MW with a beam energy of 70 keV. Beam energy, beam current, beam divergence, arc power, and several other operational parameters were measured during a pulse to analyze the long pulse properties. The increase of the cooling water temperature of the accelerator grids and plasma generator components were measured by water flow calorimetric system using thermocouples. The temperature rises of the filament electrodes of the ion source and the G1 grids (plasma grids) of the accelerator turned out to be the critical factors of the long pulse operation in the current system.
RESUMO
BACKGROUND: In augmentation rhinoplasty, delayed morphologic changes are often observed with silicone implants, despite them being known as a safe implant material. The purpose of this study was to identify the cause and time course of delayed shape changes of silicone implants, through the long-term evaluation of inserted implants and their surrounding nasal soft tissues after their removal at revision rhinoplasty operations. METHODS: Two hundred twenty-one silicone implants removed during revision rhinoplasty were studied. The period of insertion ranged from 1 month to 25 years, with an average of 6 years 7 months. Calcification within the silicone implants and, when available, the capsular soft-tissue attachments were examined with the naked eye and light microscopy. RESULTS: Calcification was first observed grossly with the naked eye after 5 years 8 months of insertion. With light microscopy, calcification debris could be seen after 4 years. After implant insertion for more than 9 years, focal calcification could be seen in 50 percent of implants. When implants had been inserted for more than 15 years, a denatured type of large calcification was clearly observed. Plasma cell, macrophage, and neutrophil proliferation was noted in the soft-tissue capsule surrounding the superficial calcifications in those individuals with an early inflammatory response, and lymphocyte proliferation was noted in those with a late inflammatory response. CONCLUSIONS: Silicone implants were noted to induce calcification when inserted for a long time, causing long-term morphologic changes. This should be taken into consideration when choosing silicone implants for augmentation rhinoplasty.
