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In recent years, a few research studies have been published on the blending of unsaturated polyester and phenolic resins for the purpose of improving the fire properties of unsaturated polyester resins. However, there has been no published study on the cure and strain monitoring of unsaturated polyester/phenolic blends during composite manufacturing. In this study, non-crimp triaxial glass fabric preforms were infused with the unsaturated polyester/phenolic blends, and the strain developments inside the composites were monitored using fibre Bragg grating sensors, as the long and complex curing stages were progressing at different temperatures. Strain-free fibre Bragg grating sensors and also thermocouples were utilised for temperature monitoring and compensation in order to obtain true strain developments and residual strains. The results were associated with a study presenting the cure analyses of unsaturated polyester/phenolic blends. The unsaturated polyester and the phenolics were found to be incompatible and exhibited different curing mechanisms in the blends, which were also observable in the strain development results. This paper has been the first attempt to (i) process these novel resin systems in the vacuum infusion process and (ii) monitor the long, complex and high-temperature cure cycles and the strain developments in the vacuum infusion process using fibre Bragg gratings. [ABSTRACT FROM AUTHOR]

This study presents the cure kinetics and cure modelling of an ambient curing unsaturated polyester (UP) resin system for its cure simulation in the vacuum infusion (VI) process. The curing of the UP resin system was investigated using differential scanning calorimetry (DSC). The dynamic DSC test measurements were conducted to find out the ultimate heat of reaction and enable experimental conversion determination for the isothermal curing. The empirical autocatalytic cure kinetics model incorporating the Arrhenius law represented the cure behaviour. The results of the cure kinetics study, the cure model, the material properties and the boundary conditions were the inputs in PAM-RTM software for the simulation of the degree of cure and the exothermic temperature during the infusion and the room temperature curing stages. The simulation results were compared with experimentally measured data. A vacuum infusion (VI) experiment involving a non-crimp glass fibre preform was performed in order to monitor the curing using thermocouples and validate the temperature simulation result. It was shown that the degree of cure and the exothermic temperature of a room temperature curing thermoset resin system during the VI process could be predicted through the steps of this study. [ABSTRACT FROM AUTHOR]

Neurosurgical patients often require prolonged laryngeal intubation. The literature regarding the management of these patients is controversial, with some series reporting increased benefits of early tracheotomy and others reporting similar benefits of prolonged transtracheal intubation. One hundred sixteen consecutive neurosurgical patients who had tracheotomies performed during a 5-year period are presented in order to clarify some of the factors involved with these issues. The complications that occurred in this series were less frequent than those reported in most of the published series. Of the 116 patients, 7 had posttracheotomy complications. These complications included stomal infections (4 patients), hemorrhage (1 patient), subglottic granulation tissue (1 patient), and tracheitis (1 patient). All complications were easily treated and caused no significant long-term morbidity. Furthermore, pulmonary care was universally facilitated by the placement of a tracheotomy. The performance of an early postinjury tracheotomy may prevent the known complications of prolonged endotracheal intubation while providing effective ventilation and pulmonary toilet through safe and comfortable access to the airway. Early postinjury tracheotomy is not associated with a high incidence of significant complications in the neurosurgical patient population.