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Displaying 101 - 125 of 452

Reappraising the appropriate use of a common meteorological quantity: Potential Temperature

December 15, 2020
Author(s)
Manuel Baumgartner, Ralf Weigel, Ulrich Achatz, Allan H. Harvey, Peter Spichtinger
The potential temperature is a widely used quantity in atmospheric science since it is conserved for air's adiabatic changes of state. Its definition involves the specific heat capacity of dry air, which is traditionally assumed as constant. However, the

New refrigerants and system configurations for vapor compression refrigeration

November 13, 2020
Author(s)
Mark McLinden, Christopher J. Seeton, Andy Pearson
The high global warming potential (GWP) of current refrigerants in cooling equipment based on the vapor-compression cycle has triggered a major effort to find and implement more environmentally benign alternatives. Here, we review the basics of the vapor

Entropy Scaling of Viscosity - II: Predictive Scheme for Normal Alkanes

October 16, 2020
Author(s)
Ian H. Bell
In this work, entropy scaling as applied to normal alkanes is used to probe the physics of entropy scaling for fluids with internal degrees of freedom. This approach results in the identification of a universal transition in the behavior of the normal

Quasiuniversal Excess Entropy Scaling in Binary Supercooled Liquids

August 27, 2020
Author(s)
Ian H. Bell, Jeppe Dyre, Trond Ingebrigtsen
Transport coefficients, such as viscosity or diffusion coefficient, show significant dependence on density or temperature near the glass transition. Although several theories have been proposed for explaining this dynamical slowdown, the origin remains to

Parallel Prefetching for Canonical Ensemble Monte Carlo Simulations

August 25, 2020
Author(s)
Harold Wickes Hatch
In order to enable large-scale molecular simulations, algorithms must efficiently utilize multi-core processors that continue to increase in total core count over time with relatively stagnant clock speeds. Although parallelized molecular dynamics (MD)

The (R)Evolution of Refrigerants

July 2, 2020
Author(s)
Mark O. McLinden, Marcia L. Huber
As we enter the "fourth generation" of refrigerants, we consider the evolution of refrigerant molecules, the ever-changing constraints and regulations that have driven the need to consider new molecules, and the advancements in the tools and property

Compact 1.7 K Cryocooler for Superconducting Nanowire Single-Photon Detectors

June 18, 2020
Author(s)
Vincent Y. Kotsubo, Joel N. Ullom, Sae Woo Nam
State-of-the-art superconductor-based cryogenic detector systems are being installed at numerous research facilities worldwide and are achieving world-record sensitivities in a variety of applications. Implementation has been greatly facilitated by closed

Ion transport across solid-state ion channels perturbed by directed strain

April 28, 2020
Author(s)
Alexander Smolyanitsky, Alta Y. Fang, Andrei Kazakov, Eugene Paulechka
We combine quantum-chemical calculations and molecular dynamics simulations to consider aqueous ion flow across non-axisymmetric nanopores in monolayer graphene and MoS2. When the pore-containing membrane is subject to uniaxial tensile strains applied in

Uncertainty analysis of adsorption measurements using commercial gravimetric sorption analyzers with simultaneous density measurement based on a magnetic-suspension balance

April 27, 2020
Author(s)
Xiaoxian Yang, Reiner Kleinrahm, Mark O. McLinden, Markus Richter
A commercial gravimetric sorption analyzer, which is based on a magnetic-suspension balance, was significantly improved to reduce the uncertainty in adsorption measurements. In a previous paper, we investigated the force-transmission error (FTE) of the

Flat-Histogram Extrapolation as a Useful Tool in the Age of Big Data

April 13, 2020
Author(s)
Nathan Mahynski, Harold Hatch, Matthew Witman, David Sheen, Jeffrey R. Errington, Vincent K. Shen
Here we review recent work by the authors to revisit the concept of extrapolating thermodynamic properties of classical systems using statistical mechanical principles. Specifically, we discuss how the combination of these principles with biased sampling

An Entropy Scaling Demarcation of Gas- and Liquid-like Fluid Behaviors

April 1, 2020
Author(s)
Ian H. Bell, Guillaume Galliero, Stephanie Delage-Santacreu, Lorenzo Costigliola
In this work we propose a generic and simple definition of a line separating gas-like and liquid-like fluid behaviors in the supercritical region. We argue that this line is defined by the location of the minimum of the macroscopically scaled viscosity
Displaying 101 - 125 of 452
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