Experiments with a fully instrumented split Stirling cryocooler

A practical model that can be used to accurately size and optimally split stirling cryocoolers is discussed. A practical model that could be used to extrapolate existing designs to meet different specifications was developed. However, to do this detailed knowledge of the dynamic operating parameters of this type of cryocooler is required. The first stage is to fully instrument a refrigerator so that various dynamic parameters can be measured. The second stage involves the application of these measurements to the design and optimization of a range of coolers

Social Security Privatization and Market Risk

Under Social Security privatization, workers would be allowed to divert some of the money that currently goes to Social Security into private accounts. This would expose them to market risk, that is, the risk of a substantial drop in equity prices or of a prolonged bear market. This could result in generations of workers with less money than they thought they would have for retirement. Depending on a worker's birth date, if the privatization approach proposed by President Bush's Commission to Strengthen Social Security had been enacted at the start of the Social Security program, the retirement benefits generated from putting 10% of earnings in a private account for 35 years would have ranged from 100% to less than 20% relative to pre-retirement earnings. The extraordinarily high retirement income generated from the booming 1990s stock market was the equivalent of winning the generational lottery-unlikely to be repeated regularly. Even under these beneficial circumstances, a privatized system could have cost the government more than $1 trillion in today's dollars over the past 3 decades if the government decided to help out those who accumulated too little for retirement. The primary alternative to a government bailout of the Social Security system, older workers working longer, would likely not generate the desired results. Workers wanting to work longer would create labor market pressures typically at times when unemployment is already high. Copyright 2006 by The Policy Studies Organization.