Abstract: A polyetherpolyol for use in production of polyurethane includes polyetherpolyol carbons having stereoregularity of syndiotactic triad. Further, a method of preparing such polyetherpolyol is provided. The polyurethane resulting from stereoregular polyetherpolyol is superior in physical properties to polyuretanes obtained by use of atactic polyetherpolyol.

Abstract: An air sampler is designed for a predetermined flow rate. The air flow is admitted to at least two impactors operating in parallel. Preferably the inlet nozzles and the outlet orifices of each impactor are sized to achieve predetermined cut-off sizes of particles; preferably the composite curve of all the impactors will mimic a predetermined particle sampling efficiency curve.

Abstract: Disclosed is polyetherpolyol for use in production of polyurethane, characterized in that polyetherpolyol carbons have stereoregularity of syndiotactic triad. Further, a method of preparing such polyetherpolyol is provided. Therefore, polyurethane resulting from stereoregular polyetherpolyol is superior in physical properties to polyuretanes obtained by use of atactic polyetherpolyol.

Abstract: A constant flow of air through a personal air sampler is provided regardless of changes in the air flow path, by altering the pump speed as a function of the power taken by the pump. The characteristics of the pump are precalibrated to provide a constant used together with the square of the voltage appearing across the motor armature coils (applied voltage minus back Emf), which reflects the power currently used, to adjust the motor speed and thus provide a constant flow of air under changing conditions of resistance.

Abstract: A passive air sampler is designed to facilitate emptying granular or particulate adsorbent from it directly into a thermal desorption tube or other vessel for use in an analytical instrument. The preferred form has an adsorbent container in a conical or funnel-like shape.

Abstract: A passive air sampler is designed to facilitate emptying granular or particulate adsorbent from it directly into a thermal desorption tube or other vessel for use in an analytical instrument. The preferred form has an adsorbent container in a conical or funnel-like shape.

Abstract: A method for calibrating a personal air sampler. A desired flow rate is set, the actual rate measured and recorded through a plurality of runs, the results are automatically averaged and compared to the desired flow and the pump is automatically adjusted accordingly. The process may be repeated for a plurality of selected flow rates, and a best-fit curve computed to cover the entire range. Stability is tested by a series of sets of runs to determine erratic behavior, and an overall calibration is conducted by performing such a series of runs at each of several set point flows.

Abstract: A method for calibrating a personal air sampler. A desired flow rate is set, the actual rate measured and recorded through a plurality of runs, the results are automatically averaged and compared to the desired flow and the pump is automatically adjusted accordingly. The process may be repeated for a plurality of selected flow rates, and a best-fit curve computed to cover the entire range. Stability is tested by a series of sets of runs to determine erratic behavior, and an overall calibration is conducted by performing such a series of runs at each of several set point flows.

Abstract: A method for concentrating airborne particles and microorganisms by injecting them into a swirling air flow from where they are removed into one or more receiving tubes. The swirling air motion and the aerosol injection into it are achieved by pushing or drawing the airborne particles and microorganisms through one or more nozzles that are directed at an angle towards the surface of the containment vessel. The ratio of air flow rate into the vessel to the air flow rate through the receiving tube is equal to the maximum aerosol concentrating ratio desired.

Abstract: A method for the collection of solid or liquid particles suspended in air (aerosol). The method involves abstracting a quantity of air through a curved, porous plate with evenly spaced holes which are designed to give an accurate sample of the particle content over defined size ranges. This method differs from similar methods in that it (1) provides a minimal bias in the results from the effects of ambient air velocity or direction, (2) provides a more even distribution of particles over a collection medium, and (3) enables exclusion of particles exceeding defined upper size limits.

Abstract: An aerosol sampler for use with a source of vacuum. Air is drawn through a perforated hemisphere, directing small particles and aerosols for collection on a filter surface downstream of the hemisphere. A high collection efficiency is demonstrated.

Abstract: A method for collecting airborne particles and microorganisms by injecting them into a swirling air flow from where they are removed onto a dry surface, a surface coated with an adhesive material or a surface wetted by a liquid that is swirled onto that surface from a liquid reservoir below. The swirling air motion and the aerosol injection into it are achieved by pushing or drawing the airborne particles and microorganisms through one or more nozzles that are directed at an angle towards the collection surface.

Abstract: An apparatus for collecting airborne particles and microorganisms by injecting them into a swirling air flow from where they are removed onto a dry surface, a surface coated with an adhesive material or a surface wetted by a liquid that is swirled onto that surface from a liquid reservoir below. The swirling air motion and the aerosol injection into it are achieved by pushing or drawing the airborne particles and microorganisms through one or more nozzles that are directed at an angle towards the collection surface. Each entire nozzle or only its exit section are aligned along the axis of aerosol flow injection into the swirling air flow. The apparatus consists of one piece or of three main components that are assembled to form one unit and are comprised of one inlet section, one nozzle section, and one collection vessel.

Abstract: An air or gas sampling device utilizes a small tube calibrated under isothermal conditions. The relationship of pressure at the input end of the tube to flow is plotted and stored in a microprocessor for comparison with pressure monitored during sample pumping. Pulsations in flow caused by the air or gas pump can be neutralized by a damper comprising a small chamber having a diaphragm for one wall.