Category: Research

Recipients of Summer Undergraduate Research Fellowships (SURFs) will present end-of-summer project updates Monday and Tuesday (Aug. 12 and 13), from 9 to 11 a.m., in Fisher 139.

From Tech Today.

SURF award recipients in physics include:

Joseph Charnawskas
Advisor: Raymond Shaw
The Effects of the Gravitational Force on Water Particles in a Turbulent Flow

Mick Small
Advisor: Yoke Khin Yap
Photovoltaic Responses of Quantum Dot Sensitized ZnO Nanowires

Angela Small (Honor’s Institute)
Advisor: Jacek Borysow
Analysis of Artificial Breath Samples Using Raman Spectroscopy for Medical Diagnosis

Kevin Rocheleau (Honor’s Institute)
Advisor: Petra Huentemeyer
Analysis and Modeling of Diffuse Gamma-Ray Emission from the Cygnus Region using FERMI and HAWC Data

Minimalist model of ice microphysics in mixed-phase stratiform clouds

Fan Yang

Advisor: Raymond Shaw

Mixed-phase clouds, which can exist days even weeks, are frequently observed in the Arctic region where they play an important role in the radiation balance. Observations also show that ice particles precipitate from these clouds nearly all time. The question of whether persistent ice crystal precipitation from supercooled layer clouds can be explained by time-dependent, stochastic ice nucleation is explored using an approximate, analytical model, and a large-eddy simulation (LES) cloud model. The updraft velocity in the cloud defines an accumulation zone, where small ice particles cannot fall out until they are large enough, which will increase the residence time of ice particles in the cloud. Ice particles reach a quasi-steady state between growth by vapor deposition and fall speed at cloud base. The analytical model predicts that ice water content (w_i) has a 2.5 power law relationship with ice number concentration (n_i). w_i and n_i from a LES cloud model with stochastic ice nucleation also confirm the 2.5 power law relationship. The prefactor of the power law is proportional to the ice nucleation rate, and therefore provides a quantitative link to observations of ice microphysical properties. Figure 1 shows LES results for two ice nucleation rates: Blue points correspond to low ice nucleation rate and red points to high ice nucleation rate. It’s clearly to see that points follow the 2.5 power law as our analytical model expected. The intercept shift predicted by the minimalist model is 1.05, which is very close to the best fitted line shift in Figure 1, 5.77-4.75=1.03. This provides a compelling link between ice microphysical properties and the ice nucleation rate within the cloud, which may be used in future analysis of cloud observation.

Reference

Yang, F., M. Ovchinnikov, R.A. Shaw (2013), Minimalist model of ice microphysics in mixed-phase stratiform clouds, Geophys. Res. Lett. doi: 10.1002/grl.50700 (accepted)

Associate Professor Claudio Mazzoleni (Physics) and his graduate student, Swarup China, published an article in the journal Nature Communications on the structure and properties of soot produced by biomass burning.

From Tech Today.

Morphology and mixing state of individual freshly emitted wildfire carbonaceous particles

DOI: 10.1038/ncomms3122

The March/April edition of the magazine Rocks & Minerals would be considerably slimmer if physics professor John Jaszczak’s contributions were extracted.

With John Rakovan (Miami University), he coordinated a series of articles on mining in the Arusha region of Tanzania. He coauthored “Miracle at Merelani,” an article on minerals found at the Karo Mine, providing electron microscope images and photos of many showy specimens from the Seaman Mineral Museum. He also edited a pictorial of Merelani, a village near the mine.

In addition, he coauthored “Fluorapatite from a Remarkable Occurrence of Graphite and Associated Minerals,” providing three photos for the article.

Lastly, Jaszczak wrote the Word to the Wise column entitled “Raman Spectroscopy in the Identification and Study of Minerals,” which introduced readers to this powerful tool for identifying and characterizing minerals.

From Tech Today.

Yoke Khin Yap (Physics) has received a $140,000 research grant for “Synthesis and Characterization of Functional Boron Nitride Nanostructures” from the National Science Foundation. It is for the first year of a three-year project totaling $420,000.

From Tech Today.

Claudio Mazzoleni (Physics) has received $39,937 grant from the US Department of Energy, for a three-year, $132,465 research project, ” Atmospheric Transport: Understanding Results from the DOE’s 2010 CARES and 2012 ClearfLo Campaigns.”

From Tech Today.

Assistant Professor Claudio Mazzoleni (Physics/EPSSI), “Collaborative Research: Aging of Black Carbon during Atmospheric Transport: Understanding Results from the DOE’s 2010 CARES and 2012 ClearfLo Campaigns,” DOE.

From Tech Today.