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.

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.

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.

Molecular dynamics simulation of geminal dicationic ionic liquids [Cn(mim)2][NTf2]2 – structural and dynamical properties

2018 ◽  
Vol 20 (1) ◽  
pp. 435-448 ◽  
Author(s):  
Majid Moosavi ◽  
Fatemeh Khashei ◽  
Elaheh Sedghamiz
Keyword(s):  
Molecular Dynamics ◽  
Ionic Liquids ◽  
Molecular Dynamics Simulation ◽  
Liquid Phase ◽  
Molecular Basis ◽  
Dynamics Simulation ◽  
Bulk Liquid ◽  
Fundamental Understanding ◽  
Dicationic Ionic Liquids ◽  
Dynamical Properties

The structural and dynamical properties of two dicationic ionic liquids, i.e. [Cn(mim)2][NTf2]2 with n = 3 and 5, have been studied to obtain a fundamental understanding of the molecular basis of the macroscopic and microscopic properties of the bulk liquid phase.

scholarly journals Nitrogen-containing Secondary Organic Aerosols Formation by Acrolein Reaction with Ammonia/Ammonium

2018 ◽  
Author(s):  
Zhijian Li ◽  
Sergey A. Nizkorodov ◽  
Hong Chen ◽  
Xiaohui Lu ◽  
Xin Yang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Phase ◽  
Gas Phase ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Bulk Liquid ◽  
Gaseous Ammonia ◽  
Similar Reaction ◽  
Ammonium Ions ◽  
Oligomeric Compounds

Abstract. Ammonia-driven carbonyl-to-imine conversion is an important formation pathway to the nitrogen-containing organic compounds (NOC) in secondary organic aerosols (SOA). Previous studies have mainly focused on the dicarbonyl compounds as the precursors of light-absorbing NOC. In this work, we investigated whether acrolein could also act as a NOC precursor. Acrolein is the simplest α,β-unsaturated mono-carbonyl compound, and it is ubiquitous in the atmosphere. Experiments probing gas-phase and surface reactions of acrolein as well as bulk liquid-phase experiments were carried out to study the reactivity of acrolein towards ammonia and ammonium ions. Molecular characterization of the products based on gas chromatography mass spectrometry, high resolution mass spectrometry, surface enhanced Raman spectrometry and Ultraviolet/visible spectrometry was used to propose possible reaction mechanisms. We observed 3-methyl pyridine (also called 3-picoline) in the gas phase in the Tedlar bag filled with gaseous acrolein and ammonia. In the liquid phase, oligomeric compounds with formulas (C3H4O)m(C3H5N)n and pyridinium compounds like (C3H4O)2C6H8N+ were observed as the products of acrolein reaction with ammonium ions. The 3-picoline could be the product of acrolein reaction with gaseous ammonia in the gas phase. The pathway to 3-picoline was proposed to be the intramolecular carbon-carbon addition of the hemiaminal which resulted from sequential carbonyl-to-imine conversions of acrolein molecules. The similar reaction of dissolved acrolein with ammonium ions leads to the formation of 3-methyl pyridinium (also called 3-picolinium) cations in the liquid phase. The (C3H4O)2C6H8N+ was a carbonyl-to-hemiaminal product from acrolein dimer and 3-picolinium cations, while the oligomeric products of (C3H4O)m(C3H5N)n were polymers of acroleins and propylene imines via carbonyl-to-imine conversion and condensation reactions. Part of the 3-picolinium could re-volatilize to the gas phase as 3-picoline, explaining the observation of gaseous 3-picoline in the bag filled with acrolein and ammonium sulfates (or chlorides) aerosols. The pH value effect on the liquid products was also studied in the bulk liquid-phase experiments. Compared to the oligomeric compounds forming in both acid and alkaline conditions, there is a tendency for the pyridinium products to be formed under moderately acidic conditions. Both the oligomeric products and the pyridinium salts are light absorbing materials. This work suggests a potential role for acrolein reaction with ammonia/ammonium as a source of light-absorbing heterocyclic NOC in SOA. Therefore, secondary reactions of α,β-unsaturated aldehydes with reduced nitrogen should be taken into account when evaluating climate and health effects of SOA.

Formation, structure, and evolution of boiling nucleus and interfacial tension between bulk liquid phase and nucleus

2005 ◽  
Vol 41 (7) ◽  
pp. 651-658 ◽  
Author(s):  
Xiao-Dong Wang ◽  
Xiao-Feng Peng ◽  
Yong Tian ◽  
Bu-Xuan Wang
Keyword(s):  
Liquid Phase ◽  
Interfacial Tension ◽  
Bulk Liquid

Experimental Investigation on Ozone Mass Transfer Coefficient Enhanced by Electric Field in Liquid Phase

2013 ◽  
Vol 864-867 ◽  
pp. 2139-2144 ◽  
Author(s):  
Yang Lin Li
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Flow Rate ◽  
Ozone Concentration ◽  
Total Mass ◽  
Gas Flow ◽  
Electrode Spacing ◽  
Gas Flow Rate

In order to improve the efficiency of ozone mass transfer in liquid phase, the method enhanced by electric field was put forward. The effect on ozone mass transfer was investigated from voltage, electrode spacing and gas flow rate. The result showed that ozone concentration in water and the total mass transfer coefficient increased correspondingly with the increase of the voltage, and ozone concentration in water and the total mass transfer coefficient increased correspondingly with increase of the electrode spacing in the range from 1 to 3 cm, and ozone concentration in water increased correspondingly with increase of the gas flow rate, but the total mass transfer coefficient reduced correspondingly.

Contributions of biofilm versus suspended bacteria in an aerobic circulating-bed biofilm reactor

2001 ◽  
Vol 43 (1) ◽  
pp. 303-310 ◽  
Author(s):  
H. Yu ◽  
B. J. Kim ◽  
B. E. Rittman
Keyword(s):  
Liquid Phase ◽  
Biofilm Reactor ◽  
The Other ◽  
Bulk Liquid ◽  
Diffusion Resistance ◽  
Diffusion Limitation ◽  
Toluene Concentration ◽  
Other Hand ◽  
Degradation Reaction

This study demonstrated that, during the two-step biodegradation of toluene in an aerobic circulating-bed biofilm reactor, biofilm and suspended bacteria played critical roles. Although the suspended bacteria were less than 1% of the total amount of biomass in the system, they transformed up to 30% of the toluene into its intermediate in the bulk liquid phase. On the other hand, most of the toluene intermediate was removed inside the biofilm, where diffusion resistance reduced the toluene concentration, thereby relieving inhibition to the degradation reaction of the intermediate. The suspended bacteria are most important for rapidly biodegraded substrates, for which diffusion limitation controls the kinetics in the biofilm. They lose importance when the effects of an inhibiting substrate must be overcome.

Single-Component Sorption/Diffusion of Cyclic Compounds from Their Bulk Liquid Phase in H-ZSM-5 Zeolite

1997 ◽  
Vol 36 (5) ◽  
pp. 1812-1818 ◽  
Author(s):  
Vasant R. Choudhary ◽  
Vikram S. Nayak ◽  
Tushar V. Choudhary
Keyword(s):  
Liquid Phase ◽  
Single Component ◽  
Bulk Liquid ◽  
Cyclic Compounds
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