Surface contamination with beryllium becomes a hazard to health only when the potential exists for resuspension in air in enough quantity and for enough time to exceed the prescribed standards for airborne exposures. There are several factors governing the rate and nature of resuspension phenomena. These factors include: the quantity and properties of the particular beryllium compound causing the contamination, the nature of the surface, activities in the vicinity, ventilation in the area which might affect the dilution of resuspended particles, and the presence of other control measures such as respiratory protection and use of wet methods. Generally, it has been found that the problem is minimal and can be easily controlled by exercising good judgement based upon consideration of pertinent factors governing resuspension, and a knowledge of the nature of beryllium toxicity.

From Summary: "An investigation of a heated jet was conducted in conjunction with tests of an axial-flow jet-propulsion engine in the Cleveland altitude wind tunnel. Pressure and temperature surveys were made across the jet 10 and 15 feet behind the jet-nozzle outlet of the engine. Surveys were obtained at pressure altitudes of 10,000, 20,000, 30,000, and 40,000 feet with test-section velocities from 30 to 110 feet per second and test-section temperatures from 60 F to -50 F. From measurements taken throughout the operable range of engine speeds, tail-pipe outlet temperatures from 500 F to 1250 F and jet velocities from 400 to 2200 feet per second were obtained."

Report presenting aerodynamic characteristics of uncambered symmetrical parabolic and double-wedge airfoils with leading-edge and trailing-edge flaps using the Busemann second-order-approximation theory. Characteristics presented include aileron effectiveness factor, rate of change of hinge-moment coefficient with aileron deflection, rate of change of the pitching-moment coefficient, and the location of the center of pressure of the airfoil-aileron combination.

"Dust and gas masks and respirators have been an effective method under certain environmental conditions to reduce the inhalation of toxic aerosols. Under many conditions, however, their efficacy has been seriously questioned. It is the purpose of this study to evaluation over-all respirator performance on fine aerosols and to develop equipment whereby a greater degree of respiratory protection may be assured with reliability for highly toxic atmospheres."