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Related papers: UCLCHEM: A Gas-Grain Chemical Code

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We develop a detailed chemical network relevant to the conditions characteristic of prestellar core collapse. We solve the system of time-dependent differential equations to calculate the equilibrium abundances of molecules and dust grains,…

Astrophysics of Galaxies · Physics 2016-07-06 Pierre Marchand , Jacques Masson , Gilles Chabrier , Patrick Hennebelle , Benoit Commerçon , Neil Vaytet

We have coupled a chemical model with two dynamical models of collapsing low mass star-forming cores to predict abundances across the core of the commonly used infall tracers, CS and HCO$^+$, at various stages of the collapse. The models…

Solar and Stellar Astrophysics · Physics 2015-05-19 Julia F. Roberts , Hugh A. W. Stace , Jonathan M. C. Rawlings

We present the Grackle chemistry and cooling library for astrophysical simulations and models. Grackle provides a treatment of non-equilibrium primordial chemistry and cooling for H, D, and He species, including H2 formation on dust grains;…

The layered graphene systems exhibit the rich and unique excitation spectra arising from the electron-electron Coulomb interactions. The generalized tight-binding model is developed to cover the planar/buckled/cylindrical structures,…

Computational Physics · Physics 2019-01-15 Chiun-Yan Lin , Jhao-Ying Wu , Chih-Wei Chiu , Ming-Fa Lin

Depletion forces play a role in the compaction and de-compation of chromosomal material in simple cells but it remains debatable whether they are sufficient to account for chromosomal collapse. We present coarse-grained molecular dynamics…

Soft Condensed Matter · Physics 2015-06-22 Tyler N. Shendruk , Martin Bertrand , Hendrick W. de Haan , James L. Harden , Gary W. Slater

The ability to design molecules while preserving similarity to a target molecule and/or property is crucial for various applications in drug discovery, chemical design, and biology. We introduce in this paper an efficient training-free…

Machine Learning · Computer Science 2025-11-18 Jiri Navratil , Jarret Ross , Payel Das , Youssef Mroueh , Samuel C Hoffman , Vijil Chenthamarakshan , Brian Belgodere

Elastic scattering of a twisted (Bessel) electron beam by CO$_2$ molecules is studied theoretically at high energies. The molecule's structure is optimized using coupled cluster theory and density functional theory with…

Quantum Physics · Physics 2026-04-20 Raul Sheldon Pinto , Rakesh Choubisa

Recent work has produced a wealth of data concerning the chemical evolution of the galactic bulge, both for stars and nebulae. Present theoretical models generally adopt a limited range of such constraints, frequently using a single…

Astrophysics of Galaxies · Physics 2009-01-29 R. D. D. Costa , W. J. Maciel , A. V. Escudero

We investigate the chemical evolution of a forming molecular cloud behind an interstellar shock wave. We conduct three-dimensional magnetohydrodynamics simulations of the converging flow of atomic gas, including a simple chemical network…

Astrophysics of Galaxies · Physics 2026-01-08 Yuto Komichi , Yuri Aikawa , Kazunari Iwasaki , Kenji Furuya

We present an open-source and validated chemical kinetics code for studying hot exoplanetary atmospheres, which we name VULCAN. It is constructed for gaseous chemistry from 500 to 2500 K using a reduced C-H-O chemical network with about 300…

Earth and Planetary Astrophysics · Physics 2017-02-22 Shang-Min Tsai , James R. Lyons , Luc Grosheintz , Paul B. Rimmer , Daniel Kitzmann , Kevin Heng

We examine several different simplified approaches for modelling the chemistry of CO in three-dimensional numerical simulations of turbulent molecular clouds. We compare the different models both by looking at the behaviour of integrated…

Astrophysics of Galaxies · Physics 2015-05-27 S. C. O. Glover , P. C. Clark

The chemical reaction network (CRN) is a widely used formalism to describe macroscopic behavior of chemical systems. Available tools for CRN modelling and simulation require local access, installation, and often involve local file storage,…

Computational Engineering, Finance, and Science · Computer Science 2015-12-07 Peter Banda , Drew Blount , Christof Teuscher

The critical behavior of collective modes and the collapsing dynamics of trapped Bose-Einstein condensates with attractive interactions are studied analytically and numerically. The time scales of these dynamics both below and above the…

Condensed Matter · Physics 2009-10-31 Hiroki Saito , Masahito Ueda

Dark matter that is dissipative may cool sufficiently to form compact objects, including black holes. Determining the abundance and mass spectrum of those objects requires an accurate model of the chemistry relevant for the cooling of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-09 Michael Ryan , Sarah Shandera , James Gurian , Donghui Jeong

We investigate the molecular evolution and D/H abundance ratios that develop as star formation proceeds from a dense-cloud core to a protostellar core, by solving a gas-grain reaction network applied to a 1-D radiative hydrodynamic model…

Astrophysics of Galaxies · Physics 2015-06-11 Yuri Aikawa , Valentine Wakelam , Franck Hersant , Robin T. Garrod , Eric Herbst

The global energy fluctuations of a low density gas granular gas in the homogeneous cooling state near its clustering instability are studied by means of molecular dynamics simulations. The relative dispersion of the fluctuations is shown…

Statistical Mechanics · Physics 2009-11-10 J. Javier Brey , M. I. Garcia de Soria , P. Maynar , M. J. Ruiz-Montero

We explore a set of single-point chemical models to study the fundamental chemical aspects of episodic accretion in low-mass embedded protostars. Our goal is twofold: (1) to understand how the repeated heating and cooling of the envelope…

Solar and Stellar Astrophysics · Physics 2013-05-09 Ruud Visser , Edwin A. Bergin

We present a new chemodynamical code based on the adaptive mesh refinement code RAMSES. The new code uses Eulerian hydrodynamics and N-body dynamics in a cosmological framework to trace the production and advection of several chemical…

Astrophysics of Galaxies · Physics 2012-02-13 C. Gareth Few , Stephanie Courty , Brad K. Gibson

Geochemical systems are known to exhibit highly variable spatiotemporal behavior. This may be observed both in non-smooth concentration curves in space for a single sampling time and also in variability between samples taken from the same…

Determination of the explosion severity parameters of biomass is crucial for the safety management and dust explosion risk assessment of biomass-processing industries. These are commonly determined following experimental tests in the 20L…

Fluid Dynamics · Physics 2022-07-28 A. Islas , A. Rodríguez Fernández , C. Betegón , E. Martínez-Pañeda , A. Pandal