Novel insights into gel layer fouling in forward osmosis process based on thermodynamic analysis: role of reverse salt diffusion

Abstract Osmosis is the movement of solvent across a permselective membrane induced by a solute-concentration gradient. Now in ‘Forward Osmosis’ it is empirically observed that the diffusion of the solute is counter to that of the solvent i.e. there is so-called “reverse salt diffusion”. However it has been recently suggested, in a theoretical paper, that if allowance is made for minor deviations from ideal semi-permeability then operation in an overlooked mode of “breakthrough” osmosis would be possible and importantly it would yield relatively large rates of osmosis. A consequential prediction was that in “breakthrough mode”, Pressure-Retarded Osmosis (PRO) would generate very high power densities exceeding those in the conventional mode by one order of magnitude. The practicality of this suggestion was explored and necessarily questions were then raised regarding the foundation of the Spiegler-Kedem-Katchalsky model. Arising from: Yaroshchuk, A., Sci. Rep. 7, 45168 (2017); 10.1038/srep45168

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Gypsum scaling in forward osmosis: Role of membrane surface chemistry

Journal of Membrane Science ◽

10.1016/j.memsci.2016.04.022 ◽

2016 ◽

Vol 513 ◽

pp. 250-259 ◽

Cited By ~ 53

Author(s):

Ming Xie ◽

Stephen R. Gray

Keyword(s):

Surface Chemistry ◽

Membrane Surface ◽

Forward Osmosis ◽

Gypsum Scaling

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On the role of diffusion in phase selection during reactions at interfaces

Journal of Materials Research ◽

10.1557/jmr.1992.0367 ◽

1992 ◽

Vol 7 (2) ◽

pp. 367-373 ◽

Cited By ~ 75

Author(s):

C.V. Thompson

Keyword(s):

Solid State ◽

Thermodynamic Analysis ◽

Phase Formation ◽

Phase Selection ◽

Transient Nucleation ◽

State Amorphization

It is argued that interdiffusion must precede nucleation of new phases during reactions at interfaces between compositionally different phases. The relative rates at which elemental components diffuse in the reacting phases control the sequence in which phases can form, and can also strongly affect the relative nucleation rates of alloy products, especially in the transient nucleation regime. While detailed predictions of the relative nucleation rates require usually unavailable knowledge of the energies of the relevant interfaces, in some cases, knowledge of the relevant diffusivities, along with a thermodynamic analysis, can lead to predictions of likely phase formation sequences. These concepts are used to explain the association of diffusional asymmetry with systems that undergo solid state amorphization, and to specify semiquantitatively the degree of asymmetry required for solid state amorphization.

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Gastroduodenal mucus bicarbonate barrier: protection against acid and pepsin

AJP Cell Physiology ◽

10.1152/ajpcell.00102.2004 ◽

2005 ◽

Vol 288 (1) ◽

pp. C1-C19 ◽

Cited By ~ 371

Author(s):

Adrian Allen ◽

Gunnar Flemström

Keyword(s):

Ph Gradient ◽

Support Surface ◽

First Line ◽

Physiological Conditions ◽

Neutral Ph ◽

Primary Function ◽

Gel Layer ◽

Mucus Gel ◽

And Control

Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection against luminal acid. The continuous adherent mucus layer is also a barrier to luminal pepsin, thereby protecting the underlying mucosa from proteolytic digestion. In this article we review the present state of the gastroduodenal mucus bicarbonate barrier two decades after the first supporting experimental evidence appeared. The primary function of the adherent mucus gel layer is a structural one to create a stable, unstirred layer to support surface neutralization of acid and act as a protective physical barrier against luminal pepsin. Therefore, the emphasis on mucus in this review is on the form and role of the adherent mucus gel layer. The primary function of the mucosal bicarbonate secretion is to neutralize acid diffusing into the mucus gel layer and to be quantitatively sufficient to maintain a near-neutral pH at the mucus-mucosal surface interface. The emphasis on mucosal bicarbonate in this review is on the mechanisms and control of its secretion and the establishment of a surface pH gradient. Evidence suggests that under normal physiological conditions, the mucus bicarbonate barrier is sufficient for protection of the gastric mucosa against acid and pepsin and is even more so for the duodenum.

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Thermodynamic analysis of the double Brayton cycle with the use of oxy combustion and capture of CO2

Archives of Thermodynamics ◽

10.2478/aoter-2013-0008 ◽

2013 ◽

Vol 34 (2) ◽

pp. 23-38 ◽

Cited By ~ 6

Author(s):

Paweł Ziółkowski ◽

Witold Zakrzewski ◽

Oktawia Kaczmarczyk ◽

Janusz Badur

Keyword(s):

Gas Turbine ◽

Thermodynamic Analysis ◽

Compression Ratio ◽

Negative Pressure ◽

Condensation Process ◽

Brayton Cycle

Abstract In this paper, thermodynamic analysis of a proposed innovative double Brayton cycle with the use of oxy combustion and capture of CO2, is presented. For that purpose, the computation flow mechanics (CFM) approach has been developed. The double Brayton cycle (DBC) consists of primary Brayton and secondary inverse Brayton cycle. Inversion means that the role of the compressor and the gas turbine is changed and firstly we have expansion before compression. Additionally, the workingfluid in the DBC with the use of oxy combustion and CO2 capture contains a great amount of H2O and CO2, and the condensation process of steam (H2O) overlaps in negative pressure conditions. The analysis has been done for variants values of the compression ratio, which determines the lowest pressure in the double Brayton cycle.

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How aqua regia overcomes the chemical inertness of cinnabar: a thermodynamic analysis in light of long-term knowledge about a reaction that has been of interest for centuries

Reviews in Inorganic Chemistry ◽

10.1515/revic-2019-0014 ◽

2019 ◽

Vol 39 (4) ◽

pp. 223-231

Author(s):

Aliyar Mousavi

Keyword(s):

Nitric Acid ◽

Hydrochloric Acid ◽

Thermodynamic Analysis ◽

16Th Century ◽

Aqua Regia ◽

Sulfide Ion ◽

Elemental Chlorine ◽

Chemical Inertness

AbstractWith the rise of the Swiss-born alchemist Paracelsus in the 16th century, the dissolution of cinnabar (red HgS) in aqua regia has repeatedly appeared in the chemical literature. This article reviews the relevant history and takes a thermodynamic approach to shed new light on the dissolution. The conclusions reveal that the reaction in which the sulfide ion is oxidized by nitric acid is the most thermodynamically favorable step in the dissolution. The importance of the role of hydrochloric acid in the dissolution, when it provides complexation, was also observed. Further, it was found that the overall effect of nitric acid is much greater than that of the aqua regia by-product elemental chlorine.

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Rate Determining Processes of Sea Ice Growth

Annals of Glaciology ◽

10.1017/s0260305500010260 ◽

1985 ◽

Vol 6 ◽

pp. 168-170 ◽

Cited By ~ 2

Author(s):

T. Kuroda

Keyword(s):

Heat Flux ◽

Growth Rate ◽

Heat Conduction ◽

Sea Ice ◽

Heat Transport ◽

Environmental Conditions ◽

Sensible Heat ◽

Analytical Expression ◽

Salt Diffusion

We have derived an analytical expression for the growth rate of sea ice by taking account of the processes relevant to the growth, eg heat conduction, diffusion of salt molecules, radiation, sensible heat transport, evaporation and so on. We discuss the role of each process as rate determining processes under various environmental conditions. It is shown that because of coupling of salt diffusion and heat conduction, the growth rate feeds back to the heat flux Qw from water to ice which controls the growth rate and that Qw decreases with the thickness I of sea ice, even if the environmental conditions are kept constant.

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