Synthesis and characterization of near monodisperse oligomeric polystyrenes

Oligomeric (<10³) polystyrenes have been synthesized on a practical scale by the use of secbutyllithium and triethylamine in cyclohexane. These samples were found to possess relatively narrow molecular weight distributions. The product analysis was accomplished by viscosity, vapour pressure osmometry, gel permeation chromatography and gas chromatography.     

Development of surgical instruments for implanting a flexible fixation device for the lumbar spine

A new flexible fixation device for the lumbar spine has been developed. This paper describes the development and evaluation of two surgical instruments required for implanting this device. Prototypes were designed, manufactured and then evaluated for use in surgery. Further evaluation was performed, if necessary, and the design finalized, in accordance with BS EN 12011. This process involved close collaboration between engineers and surgeons.     

Glass Conductance Controlled Electric Forehearth

The heating currents flow longitudinally between transverse submerged electrodes. Their arrangement distributes heating current throughout the glass body without zone control interference while using a minimum number of electrodes. Conventional gas firing remains unchanged as an alternate mode of operation. Heating is controlled to an average glass electric conductance setting (as measured in the exit half of each zone). The basic electrode and holder design is briefly described. It does not require forced cooling. The operator's control panel is explained in addition to the all solid-state measuring, calculating, and controlling system with glass level compensation. A muffled cooling system improvement is also outlined.     

Case Study: Analysis of Corrosion Patterns to Evaluate the Preaccident Configuration of an ATV Tie Rod End Connection

A forensic investigation was performed on an ATV that was involved in an accident in which the vehicle struck a tree. Postaccident, the front knuckle/tie rod end connection was found to be loose. The prevailing torque nut was found positioned at the end of the tie rod end bolt such that there was a gap between the face of the nut and the knuckle. The subject nut exhibits machining asperities that resulted from close contact with the knuckle face. EDS analysis of the corrosion product ring on the knuckle face revealed the corrosion product was zinc oxide, which had formed due to galvanic corrosion between the galvanized nut and the carbon steel knuckle. Scuffing patterns on the nut, wear patterns on the bolt, and lack of damage to the knuckle corrosion ring confirmed that the nut could not have loosened from the as-manufactured position to the postaccident position. No viable nut loosening mechanism was identified other than deliberate, manual manipulation.