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Full-Text Articles in Physics
Erratum: Experimental Study Of The Role Of Physicochemical Surface Processing On The In Ability Of Mineral Dust Particles (Atmospheric Chemistry And Physics (2011) 11 (11131-11144)), D. Niedermeier, S. Hartmann, T. Clauss, H. Wex, A. Kiselev, R. C. Sullivan, P. J. Demott, M. D. Petters, P. Reitz, J. Schneider, E. Mikhailov, B. Sierau, O. Stetzer, B. Reimann, U. Bundke, R. A. Shaw, A. Buchholz, T. F. Mentel, F. Stratmann
Erratum: Experimental Study Of The Role Of Physicochemical Surface Processing On The In Ability Of Mineral Dust Particles (Atmospheric Chemistry And Physics (2011) 11 (11131-11144)), D. Niedermeier, S. Hartmann, T. Clauss, H. Wex, A. Kiselev, R. C. Sullivan, P. J. Demott, M. D. Petters, P. Reitz, J. Schneider, E. Mikhailov, B. Sierau, O. Stetzer, B. Reimann, U. Bundke, R. A. Shaw, A. Buchholz, T. F. Mentel, F. Stratmann
Michigan Tech Publications
No abstract provided.
Experimental Study Of The Role Of Physicochemical Surface Processing On The In Ability Of Mineral Dust Particles, D. Niedermeier, S. Hartmann, T. Clauss, H. Wex, A. Kiselev, R. C. Sullivan, P. J. Demott, M. D. Petters, P. Reitz, J. Schneider, E. Mikhailov, B. Sierau, O. Stetzer, B. Reimann, U. Bundke, R. A. Shaw, A. Buchholz, T. F. Mentel, F. Stratmann
Experimental Study Of The Role Of Physicochemical Surface Processing On The In Ability Of Mineral Dust Particles, D. Niedermeier, S. Hartmann, T. Clauss, H. Wex, A. Kiselev, R. C. Sullivan, P. J. Demott, M. D. Petters, P. Reitz, J. Schneider, E. Mikhailov, B. Sierau, O. Stetzer, B. Reimann, U. Bundke, R. A. Shaw, A. Buchholz, T. F. Mentel, F. Stratmann
Michigan Tech Publications
During the measurement campaign FROST 2 (FReezing Of duST 2), the Leipzig Aerosol Cloud Interaction Simulator (LACIS) was used to investigate the influence of various surface modifications on the ice nucleating ability of Arizona Test Dust (ATD) particles in the immersion freezing mode. The dust particles were exposed to sulfuric acid vapor, to water vapor with and without the addition of ammonia gas, and heat using a thermodenuder operating at 250 °C. Size selected, quasi monodisperse particles with a mobility diameter of 300 nm were fed into LACIS and droplets grew on these particles such that each droplet contained a …
Effect Of Coarse Marine Aerosols On Stratocumulus Clouds, Yoav Lehahn, Ilan Koren, Orit Altaratz, Alexander Kostinski
Effect Of Coarse Marine Aerosols On Stratocumulus Clouds, Yoav Lehahn, Ilan Koren, Orit Altaratz, Alexander Kostinski
Department of Physics Publications
In contrast to fine anthropogenic aerosols (radii ∼μm), large aerosol particles are thought to enhance cloud droplet growth, promote precipitation formation and reduce cloud albedo. While shown in cloud simulation models, the impact of coarse aerosols on marine stratocumulus clouds lacks observational evidence. Here, by combining data from AMSR‐E and MODIS, both aboard NASA's satellite Aqua, we link the amount of coarse marine aerosols emitted to the atmosphere through wind‐driven processes with the size of cloud droplets, at the world's largest deck of marine stratocumulus clouds over the southeastern Pacific. For constrained meteorological conditions, approximately 1/2 of the change in …
Evolution And Distribution Of Record-Breaking High And Low Monthly Mean Temperatures, Amalia Anderson, Alexander Kostinski
Evolution And Distribution Of Record-Breaking High And Low Monthly Mean Temperatures, Amalia Anderson, Alexander Kostinski
Department of Physics Publications
The ratio of record highs to record lows is examined with respect to extent of time series for monthly mean temperatures within the continental United States for 1900–2006. In counting the number of records that occur in a single year, the authors find a ratio greater than unity in 2006, increasing nearly monotonically as the time series increases in length via a variable first year over 1900–76. For example, in 2006, the ratio of record highs to record lows ≈ 13:1 with 1950 as the first year and ≈ 25:1 with 1900 as the first year; both ratios are an …
Mechanism Behind The Switching Of Current Induced By A Gate Field In A Semiconducting Nanowire Junction, Subhasish Mandal, Ranjit Pati
Mechanism Behind The Switching Of Current Induced By A Gate Field In A Semiconducting Nanowire Junction, Subhasish Mandal, Ranjit Pati
Department of Physics Publications
We propose an orbital-controlled model to explain the gate field induced switching of current in a semiconducting PbS-nanowire junction. A single-particle scattering formalism in conjunction with a posteriori density-functional approach involving a hybrid functional is used to study the electronic current; both first- and higher-order Stark effects are explicitly treated in our model. Our calculation reveals that after a threshold gate voltage, orbital mixing produces p components at the S atoms in the participating orbitals. This results in an interlayer orbital interaction that allows electrons to delocalize along the channel axis. As a consequence, a higher conductance state is found. …
Heterogeneous Ice Nucleation: Exploring The Transition From Stochastic To Singular Freezing Behavior, D. Niedermeier, R. A. Shaw, S. Hartmann, H. Wex, T. Clauss, J. Voigtländer, F. Stratmann
Heterogeneous Ice Nucleation: Exploring The Transition From Stochastic To Singular Freezing Behavior, D. Niedermeier, R. A. Shaw, S. Hartmann, H. Wex, T. Clauss, J. Voigtländer, F. Stratmann
Michigan Tech Publications
Heterogeneous ice nucleation, a primary pathway for ice formation in the atmosphere, has been described alternately as being stochastic, in direct analogy with homogeneous nucleation, or singular, with ice nuclei initiating freezing at deterministic temperatures. We present an idealized, conceptual model to explore the transition between stochastic and singular ice nucleation. This "soccer ball" model treats particles as being covered with surface sites (patches of finite area) characterized by different nucleation barriers, but with each surface site following the stochastic nature of ice embryo formation. The model provides a phenomenological explanation for seemingly contradictory experimental results obtained in our research …
Record Setting During Dispersive Transport In Porous Media, Yaniv Edery, Alexander Kostinski, Brian Berkowitz
Record Setting During Dispersive Transport In Porous Media, Yaniv Edery, Alexander Kostinski, Brian Berkowitz
Department of Physics Publications
How often does a contaminant ‘particle’ migrating in a porous medium set a distance record, i.e., advance farther from the origin than at all previous time steps? This question is of fundamental importance in characterizing the nature of the leading edge of a contaminant plume as it is transported through an aquifer. It was proven theoretically by Majumdar and Ziff (2008) that, in the 1d case for pure diffusion, record setting of a random walker scales with n1/2, where n is the number of steps, regardless of the length and time distribution of steps. Here, we use numerical …
First-Principles Study Of Strain-Induced Modulation Of Energy Gaps Of Graphene/Bn And Bn Bilayers, Xiaoliang Zhong, Yoke Khin Yap, Ravindra Pandey, Shashi P. Karna
First-Principles Study Of Strain-Induced Modulation Of Energy Gaps Of Graphene/Bn And Bn Bilayers, Xiaoliang Zhong, Yoke Khin Yap, Ravindra Pandey, Shashi P. Karna
Department of Physics Publications
First-principles calculations based on density functional theory are performed on graphene/BN and BN bilayers to investigate the effect of the strain on their energy gaps. For the graphene/BN bilayer, the bands have characteristic graphenelike features with a small band gap at K. Application of strain modulates the band gap, whose magnitude depends on the strength of interaction between constituent monolayers. For the BN bilayer, on the other hand, a large band gap is predicted, which remains nearly the same for small strains. The increased inhomogeneity in charge density of different carbon sublattices due to a stronger interplanar interaction is the …
Codoping In A Single Molecular Junction From First Principles, Subhasish Mandal, Ranjit Pati
Codoping In A Single Molecular Junction From First Principles, Subhasish Mandal, Ranjit Pati
Department of Physics Publications
Using a codoping model, where a cation and an anion are introduced simultaneously into the host to maintain charge neutrality, we probed the electron transport characteristics in a single molecular junction. We used the 1, 12-dicarba-closo-dodecaborane inorganic molecule as a precursor, replaced one of the vertex carbon atoms by a boron atom, and simultaneously decorated it with an endohedrally doped alkali atom (Li or Na) to look into the role of dopant atoms in the conductivity. The commonly used thiolate anchoring groups are used to attach the molecule between two gold electrodes, and a parameter-free, first-principles, single-particle Green’s …
Homogeneous And Heterogeneous Ice Nucleation At Lacis: Operating Principle And Theoretical Studies, S. Hartmann, D. Niedermeier, J. Voigtländer, T. Clauss, R. A. Shaw, H. Wex, A. Kiselev, F. Stratmann
Homogeneous And Heterogeneous Ice Nucleation At Lacis: Operating Principle And Theoretical Studies, S. Hartmann, D. Niedermeier, J. Voigtländer, T. Clauss, R. A. Shaw, H. Wex, A. Kiselev, F. Stratmann
Michigan Tech Publications
At the Leipzig Aerosol Cloud Interaction Simulator (LACIS) experiments investigating homogeneous and heterogeneous nucleation of ice (particularly immersion freezing in the latter case) have been carried out. Here both the physical LACIS setup and the numerical model developed to design experiments at LACIS and interpret their results are presented in detail. < br> < br> Combining results from the numerical model with experimental data, it was found that for the experimental parameter space considered, classical homogeneous ice nucleation theory is able to predict the freezing behavior of highly diluted ammonium sulfate solution droplets, while classical heterogeneous ice nucleation theory, together with the assumption of …