Gas permeability of porous silicon nanostructures.

The gas (air and hydrogen) flow through porous silicon ( PS ) nanostructures is studied. Being well described by Darcy's law, the gas flow measurements allow us to deduce PS permeability values, which are measured to be 10(-16) - 10(-15) m(2), corresponding to the 50-70% porosity range. A strong porosity dependence of the PS intrinsic permeability is found to be in good agreement with Kozeny's model.

Internet/Web-based administration of benefits.

Most funds will face the challenge of deploying at least some Web-based functionality in the near future, if they have not already done so. Clear objectives and careful planning will help ensure success. Issues that must be considered include support requirements, security concerns, functional business objectives, and employer and member Web access.

Determining the optimal physician mix in health maintenance organizations.

Described is a simulation model for forecasting the appropriate mix of physicians needed to meet health service demands of patients in managed health care organizations. The model can be used by executives of managed health care organizations to plan for physician staffing levels by specialty. Uncertainties such as changes in the population size served by the managed health care organization, new developments in health care delivery technologies and changing attitudes of the population regarding healthier lifestyles are considered in this model.

A problem associated with the use of a calomel reference electrode in an ISE analytical system.

It was discovered during the testing of a new diluted ISE analytical system that a dark deposit formed in the vicinity of the reference electrode junction and on the junction membrane over a 1-3 month period of use. The effect of the black deposit was to shorten the life of the restricted flow reference membrane and increase the time required to maintain the system in its optimum state. Elemental analysis of the deposit revealed the presence of both mercury and sulfur.