Nagendra Raparthi - Research Highlights

1. A novel filter-based method for integrated aerosol hygroscopicity and chemical composition

Developed a filter-based method to quantify aerosol particle hygroscopicity under near-saturation RH conditions and chemically characterize the same particles, enabling direct investigation of composition-hygroscopicity relationships (https://doi.org/10.5194/amt-18-603-2025).
Applied to fresh and aged smoke in North America, the method revealed how changes in aerosol molecular composition influence particle hygroscopicity (https://doi.org/10.1021/acsestair.5c00507).

2. How do physicochemical properties of organic molecules govern aerosol hygroscopicity?

Investigated how the physicochemical properties of organic molecules influence aerosol water uptake, revealing their complex interplay in determining hygroscopicity (https://doi.org/10.1021/acsestair.5c00061).

3. Real-world individual vehicle emission factors and super-emitter contributions

Combined low-cost sensing and vehicle identification to quantify real-world individual vehicle emission factors (https://doi.org/10.1016/j.atmosenv.2023.119869).

4. How does particulate matter oxidative potential differ between roadside and urban background environments?

Characterized PM₂.₅ oxidative potential across roadside and urban background environments, revealing distinct spatial and temporal variability (https://doi.org/10.1016/j.envpol.2023.122514).

5. Real-world vehicular activity and emissions

A survey of ~4,500 vehicles across 18 Mumbai fuel stations enabled vehicle survival analysis and bottom-up estimation of real-world vehicular emissions (https://doi.org/10.1016/j.jclepro.2022.134145).

6. Real-world vehicular emission factors and source apportionment from road tunnel measurements in India

Across three complementary studies, real-world vehicle emission factors were quantified for light-duty and mixed vehicle fleets using road-tunnel measurements. Detailed chemical characterization of tunnel particulate matter enabled the identification and apportionment of major road-traffic sources.