Saeid Kamal

Images reveal that atmospheric particles can undergo liquid–liquid phase separations

A large fraction of submicron atmospheric aerosol particles contains both organic material and inorganic salts. As the relative humidity cycles in the atmosphere and the water content of the particles correspondingly changes, these mixed particles can undergo a range of phase transitions, possibly including liquid–liquid phase separation. If liquid–liquid phase separation occurs, the gas-particle partitioning of atmospheric semivolatile organic compounds, the scattering and absorption of solar radiation, and the reactive uptake of gas species on atmospheric particles may be affected, with important implications for climate predictions. The actual occurrence of liquid–liquid phase separation within individual atmospheric particles has been considered uncertain, in large part because of the absence of observations for real-world samples. Here, using optical and fluorescence microscopy, we present images that show the coexistence of two noncrystalline phases for real-world samples collected on multiple days in Atlanta, GA as well as for laboratory-generated samples under simulated atmospheric conditions. These results reveal that atmospheric particles can undergo liquid–liquid phase separations. To explore the implications of these findings, we carried out simulations of the Atlanta urban environment and found that liquid–liquid phase separation can result in increased concentrations of gas-phase NO3 and N2O5 due to decreased particle uptake of N2O5.

MICROWAVE SPECTROSCOPY OF THERMALLY EXCITED QUASIPARTICLES IN YBA2CU3O6.99

We present here the microwave surface impedance of a high purity crystal of

Femtosecond laser irradiation of metallic surfaces: effects of laser parameters on superhydrophobicity

YBa_2Cu_3O_{6.99}

Laser-Patterned Super-Hydrophobic Pure Metallic Substrates: Cassie to Wenzel Wetting Transitions

measured at 5 frequencies between 1 and 75 GHz. This data set reveals the main features of the conductivity spectrum of the thermally excited quasiparticles in the superconducting state. Below 20 K there is a regime of extremely long quasiparticle lifetimes, due to both the collapse of inelastic scattering below

Surface impedance studies of YBCO

T_c

C-AXIS ELECTRODYNAMICS OF YBA2CU3O7-DELTA

and the very weak impurity scattering in the high purity

Observation of Weak-Limit Quasiparticle Scattering via Broadband Microwave Spectroscopy of a d-Wave Superconductor

BaZrO_3

The microwave surface impedance of YBa2Cu3O7 − δ

-grown crystal used in this study. Above 20 K, the scattering increases dramatically, initially at least as fast as

Bolometric technique for high-resolution broadband microwave spectroscopy of ultra-low-loss samples

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London penetration depth measurements of the heavy-fermion superconductor CeCoIn5 near a magnetic quantum critical point

.