Dynamic Performance Requirements Research Articles

Safe Transportation of Premature Infants

Increasing survival rates and earlier hospital discharge of premature infants have resulted in babies weighing less than 2500 g being transported frequently in the family car. Provision for safe motor vehicle transportation of this vulnerable population of infants is a major concern of parents and health professionals. The American Academy of Pediatrics Committee on Injury and Poison Prevention and the Committee on Fetus and Newborn believe that specific guidelines should be followed to ensure proper selection and use of car seats and other occupant restraint devices for low-weight infants. Currently, Federal Motor Vehicle Safety Standard 213, which established design and dynamic performance requirements for child restraint systems, applies to children weighing up to 50 lb, but no minimum weight limit is established in the standard. Most safety restrains on the market are designed for infants weighing more than 7 lb (3.1 kg), and only recently have studies been done which allow some prediction of the protective capabilities of restraint devices for infants weighing less than 7 lb.1,2 Initial research has indicated that some infants, particularly premature, low-weight infants, may be subject to oxygen desaturation when placed in an upright position in car safety seats.3,4 Both rate of growth and neurologic maturation may influence potential risk of respiratory compromise in these and other seating devices. Further investigations will be necessary to precisely define the population at risk and the variety of situations in which risk occurs. Proper positioning of small infants in car seats is important to minimize the risk of respiratory compromise while providing protection for the infant in the event of a crash or sudden stop.

System requirements for dynamic performance and response of generating units

Starting from a discussion of the fundamental characteristics of modern interconnected power systems, this paper goes on to categorize requirements for dynamic performance and response imposed on the aggregate generation which supplies the system. Both normal and abnormal operating modes are considered. The performance and response requirements are shown to stem from basic needs to maintain voltage, frequency, time, and continuity of service as well as the secondary requirements of maintaining operating economies and controlling inadvertent interchange between neighboring power systems. Typical data taken from operating records are used to illustrate and quantify several of the response requirements.

Can electric actuators meet missile requirements?

ONE OF THE vital components of a missile is the device used to position the thrust directors or control surfaces. In addition to satisfying rather stringent dynamic performance requirements, this device must be highly reliable. Missile designers favor hydraulically operated actuators because of their high dynamic performance capabilities, relatively low weight, and small size.1 However, the hydraulic actuators have still not reached the desired reliability because of sensitivity to dirt particles and other factors.