Abstract: Provided are devices and methods for the collection of bioaerosols (such as viruses, bacteria, and proteins) from the exhaled breath of humans and/or animals, for the purpose of determining, for example, particle size, generation rate, diseases and interventions for particle release.

Abstract: One aspect of the invention relates to the devices and methods for the collection of bioaerosols (such as viruses, bacteria, and proteins) from the exhaled breath of humans and/or animals, for the purpose of determining, for example, particle size, generation rate, diseases and interventions for particle release.

Abstract: The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.

Abstract: The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.

Abstract: The present disclosure is directed to embodiments of systems for measuring nitrate levels. The systems disclosed herein may include a sample inlet to permit introduction of a gas sample from which nitrate levels may be measured and a filter downstream from the sample inlet to trap particles. A first heating zone to volatilize the trapped particles may be coupled to the filter. Situated between the filter and the sample inlet may be a gas inlet to provide a secondary stream of gas to be passed over the trapped particles to minimize oxidation of low nitrogen containing compounds during heating. Downstream from the filter may be a second heating zone to heat a pathway adjacent to the filter to minimize particles depositing on internal surfaces of the pathway, and downstream from the second heating zone may be an analyzer to measure nitrate levels of the gas sample downstream from the filter. Also disclosed herein are methods for measuring nitrate levels.

Abstract: The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.

Abstract: The systems and methods described herein relate to the measurement of nitrate levels in a sample of gas, for example, air, exhaust, or other sources of gas. Moreover, the systems and methods described herein are capable of operating using short sample collection periods, permitting rapid data collection and finely time-resolved nitrate monitoring over a span of time. Additionally, ambient nitrate can effectively be distinguished from other airborne particles, such as sulfate and carbon.

Abstract: The present disclosure relates to a method of collecting particles in a gas sample comprising impacting particles in the gas sample on a porous material, as well as to impactors wherein an inertial impactor includes a porous substrate.

Abstract: Methods and apparatus for the continuous monitoring of ambient particulate mass in a gas sample encompassing the monitoring of PM.sub.10, (particulate matter greater than 10 .mu.m) and coarse particles (2.5 to 10 .mu.m), the determination of the size distribution of particles, the determination of particle density and the determination of particle-bound water, utilizing such laboratory equipment as an inertial impactor, a virtual impactor, diffusion dryer(s), HEPA filter(s), particulate matter collector(s), and pressure transducer(s).

Abstract: A method for continuously measuring particulate nitrate in a gas sample, comprising the steps of passing the gas sample through an inertial impactor with a 50% cut off at 2.5 microns, removing ambient pollutant gases from the gas with diffusion denuders, passing the gas through a first path so as to contact the gas with a coated filter so as to convert particulate nitrate to nitric acid vapor or passing the gas through a second path so as to contact the gas with coated filters to trap particulate nitrate and ammonia, and measuring nitric acid vapor and residual ambient pollutant gases produced from the first path and residual ambient pollutant gases produced from the second path with a chemiluminescent monitor, the difference in the signal produced from the gases from the two paths being a measurement of the particulate nitrate in the gas sample.

Abstract: A virtual impactor that can remove essentially all of the particles from an airstream is disclosed. Disclosed are a method of separating particles from the airstream using this virtual impactor, a method of concentrating the particulate matter in an airstream, and the concentrated airstream.

Abstract: Apparatus for measuring the amount of particulate matter in a gas having a gas supply, a first particulate matter collector downstream of the gas supply and in gaseous communication with the gas supply, and a second particulate matter collector downstream of the gas supply and in gaseous communication with the gas supply. Gas from the gas supply to the second particular matter collector is passed through a particle remover to remove particulate matter prior to contact of gas from the gas supply with the second particulate matter collector. A pressure sensor is provided to measure differential pressure between the first particulate matter collector and the second particulate matter collector, and at least one pump to cause gas to pass from the gas supply to the first particulate matter collector and the second particulate matter collector.

Abstract: A virtual impactor that can remove essentially all of the particles from an airstream is disclosed. Also disclosed are a method of separating particles from the airstream using this virtual impactor, a method of concentrating the particulate matter in an airstream, and the concentrated airstream.

Abstract: A denuder for collection of gases, consisting of a plurality of generally parallel elongated tubes having a surface formed from an inert non-metallic material, said tubes being configured and arranged to allow recovery of gaseous material collected on each said surface.

Abstract: An ozone monitor including an ozone reactive surface, held within a container, which is adapted to specifically react with ozone. The surface is also adapted to fail to react with nitrogen dioxide in an amount which affects ozone quantitation by more than 20% when the nitrogen dioxide is provided at a concentration of 76 ppb and ozone is provided at a concentration of 30 ppb within a test gas.