A5088418974- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Indoor Air Quality and Microbial Exposure
- Atmospheric and Environmental Gas Dynamics
- Vehicle emissions and performance
- Crystallization and Solubility Studies
- nanoparticles nucleation surface interactions
- Toxic Organic Pollutants Impact
- Catalytic Processes in Materials Science
- Phase Equilibria and Thermodynamics
- Lanthanide and Transition Metal Complexes
- Organic and Molecular Conductors Research
- Chemical Thermodynamics and Molecular Structure
- Particle Dynamics in Fluid Flows
- Magnetism in coordination complexes
- Spectroscopy and Laser Applications
- X-ray Diffraction in Crystallography
- Healthcare Systems and Challenges
- Trauma and Emergency Care Studies
- Adsorption, diffusion, and thermodynamic properties of materials
- Diffusion Coefficients in Liquids
University of British Columbia
2017-2021
Jeonbuk National University
2019
University of Waterloo
2016
Regional Municipality of Waterloo
2016
University of Calgary
1988
To predict important secondary organic aerosol (SOA) properties, information on viscosity or diffusion rates within SOA is needed. Ozonolysis of β-caryophyllene an source; however, very few rate measurements have been performed for this type and none as a function relative humidity (RH). In study, we measured RH generated from the ozonolysis using poke-flow technique. At 0 48%, was between 6.9 × 105 2.4 107 Pa s, 1.3 103 5.6 104 respectively. Based these viscosities fractional...
Abstract. The viscosities of three polyols and saccharides, all in the non-crystalline state, have been studied. Two (2-methyl-1,4-butanediol 1,2,3-butanetriol) were studied under dry conditions, third (1,2,3,4-butanetetrol) was as a function relative humidity (RH), including saccharides (glucose, raffinose, maltohexaose) RH. mean conditions range from 1.5 × 10−1 to 3.7 101 Pa s, with highest viscosity being that tetrol. Using combination data determined experimentally here literature for...
Abstract. Information on the rate of diffusion organic molecules within secondary aerosol (SOA) is needed to accurately predict effects SOA climate and air quality. Diffusion can be important for predicting growth, evaporation, reaction rates under certain atmospheric conditions. Often, researchers have predicted using measurements viscosity Stokes–Einstein relation (D∝1/η, where D coefficient η viscosity). However, accuracy this in remains uncertain. Using rectangular area fluorescence...
Measurements of the water activity-dependent viscosity aerosol particles from two techniques are compared, specifically coalescence droplets in holographic optical tweezers (HOT) and poke-and-flow experiments on deposited onto a glass substrate. These new data also compared with fitting dimer coagulation, isolation, (DCIC) measurements. The system considered this work ternary mixtures sucrose-citric acid-water sucrose-NaNO3-water, at varying solute mass ratios. Results HOT excellent...
Abstract. Information on liquid–liquid phase separation (LLPS) and viscosity (or diffusion) within secondary organic aerosol (SOA) is needed to improve predictions of particle size, mass, reactivity, cloud nucleating properties in the atmosphere. Here we report LLPS viscosities SOA generated by photooxidation diesel fuel vapors. Diesel contains a wide range volatile compounds, vapors may be good proxy for from anthropogenic emissions. In our experiments, occurred over relative humidity (RH)...
Information on the global distributions of secondary organic aerosol (SOA) phase state and mixing times within SOA is needed to predict impact air quality, climate, atmospheric chemistry; nevertheless, such information rare. In this study, we developed parameterizations for viscosity as a function relative humidity (RH) temperature based room-temperature data simulated pine tree toluene SOA. The were then used together with tropospheric RH fields water molecules in troposphere 200 nm...
Abstract. When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that molecules are well mixed within SOA particles on timescale 1 h. While this assumption has been debated vigorously in literature, issue remains unresolved part due to a lack information mixing times as function both temperature relative humidity. Using laboratory data, meteorological fields, model, we estimated how < h planetary boundary layer...
Abstract. Viscosities and diffusion rates of organics within secondary organic aerosol (SOA) remain uncertain. Using the bead-mobility technique, we measured viscosities as a function water activity (aw) SOA generated by ozonolysis limonene followed browning exposure to NH3 (referred brown or LSOA). These measurements together with viscosity reported in literature show that LSOA increases 3–5 orders magnitude aw decreases from 0.9 approximately 0.05. In addition, coefficients intrinsic...
In the solid state iodo-substituted bisdiselenazolyl radical 1c orders as a ferromagnet with TC = 10.5 K. With application of pressure rises rapidly, reaching value 27.5 K at 2.4 GPa. The accompanying structural and magnetic changes have been examined by high resolution powder X-ray diffraction DFT calculations exchange interactions.
Information on the diffusion rates of organic molecules within secondary aerosol (SOA) and biomass burning (BBOA) is needed to predict impact these aerosols atmospheric chemistry, air quality, climate. Nevertheless, no studies have measured organics SOA generated from β-caryophyllene or BBOA. Here, we in laboratory-generated BBOA as a function water activity (aw) using fluorescence recovery after photobleaching. The was by ozonolysis β-caryophyllene, pyrolysis pine wood. Only water-soluble...
Knowledge of diffusion coefficients as a function temperature in secondary organic aerosol (SOA) or proxies SOA is needed to predict atmospheric chemistry, climate, and air quality. We determined fluorescent molecule sucrose matrix (a proxy for SOA). Diffusion were strong (e.g., at water activity = 0.43, decreased by factor ∼40 the 20 K). Interestingly, apparent activation energy was similar matrix. On basis these measurements, mixing time molecules some types particles will often be >1 h...
Abstract. Information on the rate of diffusion organic molecules within secondary aerosol (SOA) is needed to accurately predict effects SOA climate and air quality. Often, researchers have predicted rates using measurements viscosity Stokes-Einstein relation (D ∝ 1/η where D coefficient η viscosity). However, accuracy this for predicting in remains uncertain. We measured coefficients over eight orders magnitude proxies including citric acid, sorbitol, a sucrose-citric acid mixture. These...
Abstract. Information on liquid-liquid phase separation (LLPS) and viscosity (or diffusion) within secondary organic aerosol (SOA) is needed to improve predictions of particle size, mass, reactivity, cloud nucleating properties in the atmosphere. Here we report LLPS viscosities SOA generated by photooxidation diesel fuel vapors. Diesel contains a wide range volatile compounds, vapors may be good proxy for from anthropogenic emissions. In our experiments, occurred over relative humidity (RH)...
Abstract. When simulating the formation and life cycle of secondary organic aerosol (SOA) with chemical transport models, it is often assumed that molecules are well mixed within SOA particles on time scale 1 h. While this assumption has been debated vigorously in literature, issue remains unresolved part due to a lack information mixing times as function both temperature relative humidity. Using laboratory data, meteorological fields model, we determine how
Abstract. Viscosities and diffusion rates of organics within secondary organic aerosol (SOA) remain uncertain. Using the bead-mobility technique, we measured viscosities as a function water activity (aw) SOA generated by ozonolysis limonene followed browning exposure to NH3 (referred brown or LSOA). These measurements together with viscosity reported in literature show that LSOA increases 3–5 orders magnitude aw decreases from 0.9 approximately 0.05. In addition, coefficients intrinsic...
Supplement S1. Conditioning times with the surrounding relative humidity.The time needed to condition