scholarly journals The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jose Luis Rivera ◽  
Homero Nicanor-Guzman ◽  
Roberto Guerra-Gonzalez
Keyword(s):  
Transition Temperature ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Order Parameter ◽  
Bulk Liquid ◽  
Influence Zone ◽  
Molecular Potential ◽  
Liquid Phases ◽  
Dynamics Simulations ◽  
Wide Zone

The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

Data-Driven Many-Body Models with Chemical Accuracy for CH4/H2O Mixtures

2020 ◽  
Author(s):  
Marc Riera ◽  
Alan Hirales ◽  
Raja Ghosh ◽  
Francesco Paesani
Keyword(s):  
Liquid Phase ◽  
Quantitative Description ◽  
Liquid Mixtures ◽  
Many Body ◽  
Energy Functions ◽  
Potential Energy Functions ◽  
Dynamics Simulations ◽  
Body Potential ◽  
Small Clusters ◽  
Many Body Interactions

<div> <div> <div> <p>Many-body potential energy functions (PEFs) based on the TTM-nrg and MB-nrg theoretical/computational frameworks are developed from coupled cluster reference data for neat methane and mixed methane/water systems. It is shown that that the MB-nrg PEFs achieve subchemical accuracy in the representation of individual many-body effects in small clusters and enables predictive simulations from the gas to the liquid phase. Analysis of structural properties calculated from molecular dynamics simulations of liquid methane and methane/water mixtures using both TTM-nrg and MB-nrg PEFs indicates that, while accounting for polarization effects is important for a correct description of many-body interactions in the liquid phase, an accurate representation of short-range interactions, as provided by the MB-nrg PEFs, is necessary for a quantitative description of the local solvation structure in liquid mixtures. </p> </div> </div> </div>

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

scholarly journals Propagation Dynamics of a Particle Phase in a Single-File Pore.

2000 ◽  
Vol 651 ◽  
Author(s):  
A.M. Lacasta ◽  
J.M. Sancho ◽  
F. Sagues ◽  
G. Oshanin
Keyword(s):  
Liquid Phase ◽  
Total Mass ◽  
Bulk Liquid ◽  
Particle Interactions ◽  
Particle Phase ◽  
Dynamic Density ◽  
Single File ◽  
Propagation Dynamics

AbstractWe study propagation dynamics of a particle phase in a single-file pore connected to a reservoir of particles (bulk liquid phase). We show that the total mass M(t) of particles entering the pore up to time t grows as (Mt) = 2m(J,ρF) √D0t, where D0 is the “bare” di usion coeffcient and the prefactor m(J,ρF) is a non-trivial function of the reservoir density ρF and the amplitude J of attractive particle-particle interactions. Behavior of the dynamic density pro les is also discussed.

A neutralization charge detection method for detecting ions under ambient and liquid-phase conditions

2016 ◽  
Vol 52 (29) ◽  
pp. 5187-5189 ◽  
Author(s):  
Ko-Keng Chang ◽  
Yi-Hong Cai ◽  
Chung-Hsuan Chen ◽  
Yi-Sheng Wang
Keyword(s):  
Liquid Phase ◽  
Detection Method ◽  
Sensitive Detection ◽  
Charge Detection ◽  
Liquid Phases

A novel neutralization charge detection method enabling the fast and sensitive detection of ions under ambient and liquid phases.

scholarly journals Perylene-like Dyes in Liquid Crystalline Media

1996 ◽  
Vol 51 (7) ◽  
pp. 843-850 ◽  
Author(s):  
Ewa Mykowska ◽  
Danuta Bauman
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Order Parameter ◽  
Liquid Crystalline ◽  
Fluorescent Dyes ◽  
Liquid Crystal Display ◽  
Isotropic Phase ◽  
Display Devices ◽  
Electrooptical Properties ◽  
Derivatives Of

Abstract The spectral and electrooptical properties of some dichroic fluorescent dyes (derivatives of 3.4,9,10-perylenetetracorboxylic acid and of 3,4,9-perylenetricarboxylic acid) in isotropic solvents and nematic liquid crystals have been studied. The order parameter of the dyes in the anisotropic matrices has been determined by means of optical spectroscopy methods. Moreover, the influence of the dye addition on the nematic-isotropic phase transition temperature of the pure host has been investigated. It was found that some of the dyes studied can be utilized in guest-host liquid crystal display devices.

scholarly journals Taurine suppresses liquid-liquid phase separation of lysozyme protein

2021 ◽  
Author(s):  
Kanae Tsubotani ◽  
Sayuri Maeyama ◽  
Shigeru Murakami ◽  
Stephen W Schaffer ◽  
Takashi Ito
Keyword(s):  
Phase Separation ◽  
Polyethylene Glycol ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Compatible Osmolyte ◽  
Hen Egg ◽  
Liquid Liquid Phase Separation ◽  
In Cells

AbstractTaurine is a compatible osmolyte that infers stability to proteins. Recent studies have revealed that liquid-liquid phase separation (LLPS) of proteins underlie the formation of membraneless organelles in cells. In the present study, we evaluated the role of taurine on LLPS of hen egg lysozyme. We demonstrated that taurine decreases the turbidity of the polyethylene glycol-induced crowding solution of lysozyme. We also demonstrated that taurine attenuates LLPS-dependent cloudiness of lysozyme solution with 0.5 or 1M NaCl at a critical temperature. Moreover, we observed that taurine inhibits LLPS formation of a heteroprotein mix solution of lysozyme and ovalbumin. These data indicate that taurine can modulate the formation of LLPS of proteins.

GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART III. THE USE OF OLEIC ACID ESTERS AS LIQUID PHASES

1961 ◽  
Vol 39 (6) ◽  
pp. 1190-1199 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Phase ◽  
Rapeseed Oil ◽  
Hydroxyl Groups ◽  
Gas Liquid Chromatography ◽  
Retention Data ◽  
Geometrical Isomers ◽  
Potassium Oleate ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Poly Ethylene

The separation of several cyclic terpene hydrocarbons and some oxygenated derivatives was studied on a variety of triglyceride and dioleate ester columns. Use of rapeseed oil, partially hydrogenated rapeseed oil, olive oil, triolein, tristearin, methyl oleate, and potassium oleate as liquid phases led to the conclusion that the presence of an esterified mono-unsaturated long-chain acid is a desirable constituent of the liquid phase. Dioleate esters of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polyethylene glycol showed useful differences in the degree of separation of both terpene hydrocarbons and oxygenated derivatives. Ether linkages, as in the di- and poly-ethylene glycol ester, also were associated with favorable separations. When the liquid phase contained free hydroxyl groups, the degree of separation of hydrocarbons and ketones was in general less favorable. The spacing of the ester groups was found to have some effect on retention data. The separation of such critical pairs of isomers as tricyclene and α-pinene, α-fenchene and camphene, and also geometrical isomers of oxygenated derivatives is facilitated by use of several of these liquid phases.

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