scholarly journals Study of the transport modeling by diffusion of pollutants through porous materials

2020 ◽  
Vol 10 (3) ◽  
pp. 5532-5535
Keyword(s):  
Metal Ions ◽  
Porous Materials ◽  
Size Distribution ◽  
Diffusion Model ◽  
Distance Function ◽  
Range Expansion ◽  
Transport Modeling ◽  
Navier Stokes ◽  
Geometric Form ◽  
Stratified Diffusion

This paper presents how distance function dispersal produces diffusion range expansion of the contamination. We construct a stratified diffusion model, which describes the dynamics of the size distribution of colonies created by distance migrants of metal ions. The model consists of a Fick's equation combined with a Navier-stokes. The model provides an estimate of range expansion in terms of the rate adsorption due to neighborhood diffusion, the leap time and the geometric form. The results explain various types of nonlinear range expansion observed in materials or biomaterials.

Microporous lanthanide metal-organic frameworks

2012 ◽  
Vol 32 (2-4) ◽  
pp. 81-100 ◽  
Author(s):  
Yao Chen ◽  
Shengqian Ma
Keyword(s):  
Optical Properties ◽  
Metal Ions ◽  
Porous Materials ◽  
Chemical Sensing ◽  
Metal Organic Frameworks ◽  
Current Status ◽  
Multifunctional Materials ◽  
Metal Organic ◽  
Lanthanide Metal ◽  
Solvent Adsorption

AbstractMicroporous metal-organic frameworks (MOFs) based on lanthanide metal ions or clusters represent a group of porous materials, featuring interesting coordination, electronic, and optical properties. These attractive properties in combination with the porosity make microporous lanthanide MOFs (Ln-MOFs) hold the promise for various applications. This review is to provide an overview of the current status of the research in microporous Ln-MOFs, and highlight their potential as types of multifunctional materials for applications in gas/solvent adsorption and separation, luminescence and chemical sensing and catalysis.

Positronium Thermalization Process in Nanoporous Materials and its Influence on the Shape of PALS Spectrum

2008 ◽  
Vol 607 ◽  
pp. 39-41
Author(s):  
Jerzy Kansy ◽  
Radosław Zaleski
Keyword(s):  
Mesoporous Silica ◽  
Pore Size Distribution ◽  
Porous Materials ◽  
Pore Size ◽  
Size Distribution ◽  
Nanoporous Materials ◽  
New Method ◽  
New Model ◽  
Conventional Models ◽  
Mcm 41

A new method of analysis of PALS spectra of porous materials is proposed. The model considers both the thermalization process of positronium inside the pores and the pore size distribution. The new model is fitted to spectra of mesoporous silica MCM-41 and MSF. The resulting parameters are compared with parameters obtained from fitting the “conventional” models, i.e. a sum of exponential components with discrete or/and distributed lifetimes.

scholarly journals Probe material choice for nuclear magnetic resonance cryoporometry (NMRC) measurements of the nano-scale pore size distribution of unconventional reservoirs

2018 ◽  
Vol 37 (1) ◽  
pp. 412-428
Author(s):  
Feng Zhu ◽  
Wenxuan Hu ◽  
Jian Cao ◽  
Biao Liu ◽  
Yifeng Liu ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Pore Size Distribution ◽  
Porous Materials ◽  
Pore Size ◽  
Size Distribution ◽  
Geological Samples ◽  
Nano Scale ◽  
Chloride Hexahydrate ◽  
Nuclear Magnetic

Nuclear magnetic resonance cryoporometry is a newly developed technique that can characterize the pore size distribution of nano-scale porous materials. To date, this technique has scarcely been used for the testing of unconventional oil and gas reservoirs; thus, their micro- and nano-scale pore structures must still be investigated. The selection of the probe material for this technique has a key impact on the quality of the measurement results during the testing of geological samples. In this paper, we present details on the nuclear magnetic resonance cryoporometric procedure. Several types of probe materials were compared during the nuclear testing of standard nano-scale porous materials and unconventional reservoir geological samples from Sichuan Basin, Southwest China. Gas sorption experiments were also carried out on the same samples simultaneously. The KGT values of the probe materials octamethylcyclotetrasiloxane and calcium chloride hexahydrate were calibrated using standard nano-scale porous materials to reveal respective values of 149.3 Knm and 184 Knm. Water did not successfully wet the pore surfaces of the standard controlled pore glass samples; moreover, water damaged the pore structures of the geological samples, which was confirmed during two freeze-melting tests. The complex phase transition during the melting of cyclohexane introduced a nuclear magnetic resonance signal in addition to that from liquid in the pores, which led to an imprecise characterization of the pore size distribution. Octamethylcyclotetrasiloxane and calcium chloride hexahydrate have been rarely employed as nuclear magnetic resonance cryoporometric probe materials for the testing of an unconventional reservoir. Both of these materials were able to characterize pore sizes up to 1 μm, and they were more applicable than either water or cyclohexane.

Formation of Platinum and Palladium Bimetallic Superfine Particles by Ultrasonic Irradiation

1997 ◽  
Vol 497 ◽  
Author(s):  
Toshiyuki Fujimoto ◽  
Shinya Terauchi ◽  
Hiroyuki Umehara ◽  
Isao Kojima ◽  
William Henderson
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Size Distribution ◽  
Ultrasonic Irradiation ◽  
Bimetallic Nanoparticles ◽  
Average Diameter ◽  
Narrow Size Distribution ◽  
Bimetallic Particles

ABSTRACTPt/Pd bimetallic nanoparticles were prepared by ultrasonic irradiation of aqueous solutions containing salts of both metal ions. Uniform bimetallic particles were found to have a 2.8 nm average diameter and a narrow size distribution. The size was similar to Pt monometallic particles, and the shape was similar to Pd monometallic particles, both prepared by ultrasound in the same way.

Scaling of Tip Vortex Cavitation Inception Noise With a Bubble Dynamics Model Accounting for Nucleus Size Distribution

2003 ◽  
Author(s):  
Chao-Tsung Hsiao ◽  
Georges L. Chahine
Keyword(s):  
Size Distribution ◽  
Vortex Flow ◽  
Bubble Dynamics ◽  
Tip Vortex ◽  
Navier Stokes ◽  
Nucleus Size ◽  
Scaling Effects ◽  
Dynamics Model ◽  
Tip Vortex Cavitation ◽  
Cavitation Inception

A Surface-Averaged Pressure (SAP) spherical bubble dynamics model accounting for a statistical nuclei size distribution was used to model the acoustic signals generated by cavitating bubbles near inception in a tip vortex flow. The flow field generated by finite-span elliptic hydrofoils is obtained by Reynolds-Averaged Navier-Stokes computations. An “acoustic” criterion which defines the cavitation inception by counting the number of acoustical signal peaks that exceed a certain level per unit time was applied to deduce the cavitation inception number for different scales. It was found that the larger scale results in more cavitation inception events per unite time because more nuclei are excited by the tip vortex at the larger scale. The nuclei size was seen to have an important effect on cavitation inception number with scaling effects due to nuclei increasing as nuclei sizes decreases.

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