Simulating microbial degradation of organic matter in a simple porous system using the 3-D diffusion-based model MOSAIC

Abstract. This paper deals with the simulation of microbial degradation of organic matter in soil within the pore space at a microscopic scale. Pore space was analysed with micro-computed tomography and described using a sphere network coming from a geometrical modelling algorithm. The biological model was improved regarding previous work in order to include the transformation of dissolved organic compounds and diffusion processes. We tested our model using experimental results of a simple substrate decomposition experiment (fructose) within a simple medium (sand) in the presence of different bacterial strains. Separate incubations were carried out in microcosms using five different bacterial communities at two different water potentials of −10 and −100 cm of water. We calibrated the biological parameters by means of experimental data obtained at high water content, and we tested the model without changing any parameters at low water content. Same as for the experimental data, our simulation results showed that the decrease in water content caused a decrease of mineralization rate. The model was able to simulate the decrease of connectivity between substrate and microorganism due the decrease of water content.

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Simulating microbial degradation of organic matter in a simple porous system using the 3-D diffusion based model MOSAIC

Biogeosciences Discussions ◽

10.5194/bgd-10-15613-2013 ◽

2013 ◽

Vol 10 (10) ◽

pp. 15613-15640

Author(s):

O. Monga ◽

P. Garnier ◽

V. Pot ◽

E. Coucheney ◽

N. Nunan ◽

...

Keyword(s):

Experimental Data ◽

Water Content ◽

Microbial Degradation ◽

Diffusion Processes ◽

Pore Space ◽

High Water ◽

High Water Content ◽

Porous System ◽

Dissolved Organic Compounds ◽

And Diffusion

Abstract. This paper deals with the simulation of microbial degradation in soil within pore space at microscopic scale. Pore space was described using sphere network coming from a geometrical modeling algorithm. The biological model was improved regarding previous work in order to include transformation of dissolved organic compounds and diffusion processes. Our model was tested using experimental results of a simple substrate decomposition (Fructose) within a simple media (the sand). Diverse microbial communities were inoculated. Separated incubations in microcosms were carried out using 5 different bacterial communities at 2 different water potentials of −10 cm and −100 cm of water. We calibrated the biological parameters by means of experimental data obtained at high water content and we tested the model without any parameters change at low water content. Same as for experimental data, our simulation results showed the decrease in water content involved the decrease of mineralisation. The model was able to simulate the decrease of connectivity between substrate and microorganism due the decrease of water content.

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Study on Diffusion Processes of Water and Proton in PEM Using Molecular Dynamics Simulation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.704-705.1266 ◽

2011 ◽

Vol 704-705 ◽

pp. 1266-1272 ◽

Cited By ~ 3

Author(s):

Lei Chen ◽

Wen Quan Tao

Keyword(s):

Experimental Data ◽

Molecular Dynamics ◽

Water Content ◽

Diffusion Processes ◽

Calculation Model ◽

Dynamics Simulation ◽

Water Molecules ◽

Hydrogen Ions ◽

Model Cell ◽

Dynamics Calculation

In this paper a molecular dynamics calculation model for the Nafion 117 membrane is constructed by Materials Studio (MS) software platform to study its micro-structure and transport properties. Based on the calculation model, cell structures of different water content of Nafion 117 membrane are obtained and the predicted density values of simulated cell are in good agreement with experimental data. Meanwhile, the diffusion processes of water molecules and hydrogen ions in the membrane are studied, respectively. The predicted diffusion coefficients of both water molecules and hydrogen ions increase with the water content, which agrees well with the variation trend of experimental data. The reasons for the deviation between numerical results and the experiment values in literature are analyzed.

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Osmotic Dehydration Process Study With Complementary Banana Peel Drying

Journal of Agricultural Studies ◽

10.5296/jas.v8i4.16347 ◽

2020 ◽

Vol 8 (4) ◽

pp. 217

Author(s):

Josinaldo Ferreira Da Silva Júnior ◽

Ângela Maria Santiago ◽

Pablícia Oliveira Galdino ◽

Newton Carlos Santos ◽

Sâmela Leal Barros ◽

...

Keyword(s):

Experimental Data ◽

Water Content ◽

Soluble Solids ◽

Convective Drying ◽

Banana Peel ◽

High Water Content ◽

Dehydration Process ◽

Total Soluble Solids ◽

Total Solids ◽

Physical Chemical

The present study aims to perform combined osmoconvective and convective drying processes on banana peel and evaluate the influence of these processes on their physical and physical-chemical properties. A factorial planning of 22 + 3 central points was carried out to evaluate the effect of the input variables: sucrose concentration varying between 40 and 60 °Brix and temperature between 40 and 60 °C, on the response variables: loss of water and mass and gain of solids in the banana peels. The drying kinetics was performed at 60 °C and empirical mathematical models were adjusted to the experimental data. The fresh peels, osmotically dehydrated, after drying process (in the optimized condition) and during 30 days of storage were characterized as for the parameters: pH, total titratable acidity (TTA), total soluble solids (TSS), TSS / TTA ratio, water content and total solids, ash, ascorbic acid, reducing sugars, color (L *, a * and b *) and water activity (Aw). The banana peels used in the experiments had a high water content and reasonable amounts of carbohydrates and ashes. The condition that showed the greatest reduction in water content and greatest gains in solids was using the temperature of 60 ° C and 60 ° Brix, being considered the optimized. The osmoconvective dehydration process resulted in a greater incorporation of total soluble solids and higher percentages of total solids in the shells. Page's mathematical model was the one that best fitted the experimental data; the effective diffusivity of the process was 2.2 x 10-8 m2.s-1. And the physical and physical-chemical parameters analyzed during the storage had small changes during the period of 30 days of storage.

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Preliminary remarks on porosity of soil aggregates in air-dry state and at pF 2.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v9i3.17617 ◽

1961 ◽

Vol 9 (3) ◽

pp. 168-173 ◽

Cited By ~ 1

Author(s):

H. Kuipers

Keyword(s):

Organic Matter ◽

Moisture Content ◽

Water Content ◽

Pore Volume ◽

Pore Space ◽

Soil Aggregates ◽

Aggregate Size ◽

Field Conditions ◽

Swelling Properties ◽

Air Voids

In pycnometer determinations of the pore volume of 2-5-mm air-dry aggregates from various soils of 1.5-2.5 and 2.6-3.5% organic-matter levels and various clay contents, the use of kerosene (S. & F. XVII [1897]) gave as good values as, and was more convenient than, the use of sand or mercury (the latter giving low porosities). The pore-space percentage of aggregates could be calculated from the water content at pF 2, when no air voids in the small aggregates are likely to occur and water between the aggregates is of no importance. Dry aggregates were only slightly denser in cores of light soils than under field conditions, and swelling was small; dry aggregates were very dense in heavy soils in which moisture content and density of aggregates appeared so closely related that it was difficult to distinguish between the effect of either on the strength of aggregates. Swelling properties and aggregate size are likely to be important factors in the structure of heavy soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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LABORATORY EQUIPMENT FOR AUTOTHERMAL REFORMING OF ORGANIC MATTER IN SUPERCRITICAL WATER

Acta Polytechnica ◽

10.14311/ap.2014.54.0015 ◽

2014 ◽

Vol 54 (1) ◽

pp. 15-18

Author(s):

Matúš Gajdoš

Keyword(s):

Organic Matter ◽

Water Content ◽

Supercritical Water ◽

High Water ◽

Processing Parameters ◽

Autothermal Reforming ◽

High Water Content ◽

Fuel Production ◽

Laboratory Equipment ◽

Efficient Operation

The ability of water to dissolve organic substances is very limited. However, its ability to dissolve them changes if pressure and temperature values reach the so-called critical point (<em>p</em> = 22.06MPa, <em>T</em> = 373.95 °C). Fluid water in this state is called supercritical water (SCW), and values of its physical properties are included among the values of such properties for liquid phase and gaseous phase. Various types of organic matter can be treated in SCW, and it is especially useful for materials that cannot be treated cost-effectively with conventional technologies (incineration, etc.). Suitable input materials are mainly industrial waste or biomass with high water content. Conventional processing of these materials requires energy-intensive drying or densification. Processing the inputs in SCW completely removes these problems, since sufficient water content is a prerequisite for creating a suitable environment for efficient operation of the system. In this paper, glycerol as a by-product of alternative fuel production was chosen for evaluation in the SCW autothermal reforming cycle. The paper analyses the influence of several processing parameters on the operation of model laboratory equipment.

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Gaining Insight into the Deformation of Achilles Tendon Entheses in Mice

10.1101/2021.01.23.427898 ◽

2021 ◽

Author(s):

Julian Sartori ◽

Sebastian Köhring ◽

Stefan Bruns ◽

Julian Moosmann ◽

Jörg U. Hammel

Keyword(s):

Computed Tomography ◽

Achilles Tendon ◽

Water Content ◽

Ex Vivo ◽

Flow Analysis ◽

High Water ◽

High Water Content ◽

Micro Computed Tomography ◽

Volume Changes ◽

Distal Tendon

AbstractUnderstanding the biomechanics of tendon entheses is fundamental for surgical repair and tissue engineering, but also relevant in biomimetics and palaeontology. 3D imaging is becoming increasingly important in the examination of soft tissue deformation. But entheses are particularly difficult objects for micro-computed tomography because they exhibit extreme differences in X-ray attenuation. In this article, the ex vivo examination of Achilles tendon entheses from mice using a combination of tensile tests and synchrotron radiation-based micro-computed tomography is reported. Two groups of specimens with different water content are compared with regard to strains and volume changes in the more proximal free tendon and the distal tendon that wraps around the Tuber calcanei. Tomograms of relaxed and deformed entheses are recorded with propagation-based phase contrast. The tissue structure is rendered in sufficient detail to enable manual tracking of patterns along the tendon, as well as 3D optical flow analysis in a suitable pair of tomograms. High water content is found to increase strain and to change the strain distribution among proximal and distal tendon. In both groups, the volume changes are higher in the distal than in the proximal tendon. These results support the existence of a compliant zone near the insertion. They also show that the humidity of the specimen environment has to be controlled. Necessary steps to extend the automatic tracking of tissue displacements to all force steps are discussed.

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Hydrogels as Antibacterial Biomaterials

Current Pharmaceutical Design ◽

10.2174/1381612824666180213122953 ◽

2018 ◽

Vol 24 (8) ◽

pp. 843-854 ◽

Cited By ~ 6

Author(s):

Weiguo Xu ◽

Shujun Dong ◽

Yuping Han ◽

Shuqiang Li ◽

Yang Liu

Keyword(s):

Mechanical Properties ◽

Drug Delivery ◽

Tissue Engineering ◽

Water Content ◽

Oxygen Permeability ◽

Structural Diversity ◽

High Water ◽

Clinical Applications ◽

High Water Content ◽

Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

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