Abstract: Methods and systems are provided for ranking search results and generating a presentation. In some implementations, a search system generates a presentation based on a search query. In some implementations, a search system ranks search results based on data stored in a knowledge graph. In some implementations, a search system identifies a modifying concept such as a superlative in a received search query, and determines ranking properties based on the modifying concept.

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.