Rotating disk electrode system for elevated pressures and temperatures.

We describe the development and test of an elevated pressure and temperature rotating disk electrode (RDE) system that allows measurements under well-defined mass transport conditions. As demonstrated for the oxygen reduction reaction on polycrystalline platinum (Pt) in 0.5M H2SO4, the setup can easily be operated in a pressure range of 1-101 bar oxygen, and temperature of 140 °C. Under such conditions, diffusion limited current densities increase by almost two orders of magnitude as compared to conventional RDE setups allowing, for example, fuel cell catalyst studies under more realistic conditions. Levich plots demonstrate that the mass transport is indeed well-defined, i.e., at low electrode potentials, the measured current densities are fully diffusion controlled, while at higher potentials, a mixed kinetic-diffusion controlled regime is observed. Therefore, the setup opens up a new field for RDE investigations under temperature and current density conditions relevant for low and high temperature proton exchange membrane fuel cells.

Correction of deformity after femoral birth fracture. 16-year follow-up.

At birth a girl sustained a displaced femoral fracture that healed with considerable shortening and angulation. The correction by growth of the deformity was followed radiographically during the entire 16-year growth period.

Bilateral femoral shortening for overgrowth in young adults.

Through 17 years ten patients were treated for psychologically unacceptable tallness by bilateral femoral shortening. All were young adults between 17 and 28 years; one was acromegalic, one had Marfans syndrome and the other were tall for unknown reasons. The amount of shortening obtained was between 6 and 16 cm. One patient was reoperated bilaterally because of insufficient stability of the pin and plate fixation. All patients healed without significant complications. For exclusive cases, which have been carefully observed over several months, bilateral shortening seems to be a safe procedure either with midshaft shortening and Küntscher nailing or subtrochanteric femoral shortening with pin and plate fixation. At review all patients were satisfied with their decision to be surgically shortened. Similar cases seem not to have been published.

Consumer hazards of plastics.

The modern consumer is exposed to a wide variety of plastic and rubber products in his day to day life: at home, work, school, shopping, recreation and play, and transport. A large variety of toxic sequellae have resulted from untoward exposures by many different routes: oral, dermal, inhalation, and parenteral. Toxic change may result from the plastic itself, migration of unbound components and additives, chemical decomposition or toxic pyrolysis products. The type of damage may involve acute poisoning, chronic organ damage, reproductive disorders, and carcinogenic, mutagenic and teratogenic episodes. Typical examples for all routes are cited along with the activites of Canadian regulatory agencies to reduce both the incidence and severity of plastic-induced disease.

Blood fluorocarbon levels following exposure to household aerosols.

Measurement of blood fluorocarbon levels was carried out in subjects exposed to a number of household aerosol products containing fluorocarbon gases as propellants. All aerosols were used according to manufacturers' recommendations. The general purpose of the study was to determine whether with normal routine exposure to a wide variety of household aerosol products fluorocarbon could be found in the blood and if so, to check the potential toxicity of the levels reached. Daily exposure to aerosols according to the study regimen lasted four consecutive weeks; this period was preceded and followed by two weeks of abstention from exposure. At the end of each of the three periods a medical examination, including evaluation of cardiac function, respiratory function studies, and hematological and functional clinical biochemical tests was performed. All tests and assessments failed to show any indication of toxicity. No trace of fluorocarbon was found in any of the blood sampled at intervals during the study.