Thermodynamic Formulation of the Pedostructure Water Retention and Shrinkage Curves: An Approach to Soil Medium Organization| Chapter 4 | Novel Perspectives of Geography, Environment and Earth Sciences Vol. 3

 The two characteristic soil moisture curves: the soil water retention curve and the shrinkage curve, necessary for the physical modeling of the hydrological and agronomic properties of the soil are, still today, entirely empirical. They have been established so far without referring to the hydrostructural and thermodynamic properties of the pedostructure, nor to the internal and hierarchical organization of the soil pedon and its horizons which are described in Hydrostructural Pedology. On the contrary, this article presents the development of these equations according to the systemic and thermodynamic paradigm of this new scientific discipline of earth sciences.  We show how the aqueous phase of the pedostructure is divided into two types of water positioned differently in the pedostructure: one in the plasma porosity of the primary aggregates and the other outside the primary aggregates in the inter-aggregate porosity. The thermodynamic equilibrium established between these two types of water has been put into equations to represent the pedostructural water retention curve h(W) resulting from this equilibrium: the suction pressure of the pedostructure as a function of the water content. Using information from simultaneous measurements of both curves, the new equations were put to the test and the theory was verified.  The implications of these findings for physical modelling in agro-environmental sciences are discussed.

Author(s) Details:

Erik Braudeau,
Qatar Foundation, Qatar Environment and Energy Research Institute, Doha, Qatar and Institut de Recherche pour le Développement, Bondy, France.

Amjad T. Assi,
Qatar Foundation, Qatar Environment and Energy Research Institute, Doha, Qatar and Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN, USA.

Hassan Boukcim,
Valorhiz SAS, Parc Scientifique Agropolis II Bat 6, Montferrier-sur-Lez, France.

Rabi H. Mohtar,
Biological and Agricultural Engineering Department, and Zachry Department of Civil Engineering, Texas A&M University, College Station, TX, USA.

Please see the link here: https://stm.bookpi.org/NPGEES-V3/article/view/9374

Oxidation Products for Methyl Ethyl Sulfide CH3SCH2CH3 under Standard Conditions- A Thermodynamic Study | Chapter 3 | Current Topics on Chemistry and Biochemistry Vol. 3

Methyl ethyl sulphides are employed in both scientific inquiry and chemical synthesis. Significant amounts of ethyl methyl sulphide are released into the atmosphere as a result of biological activity in the sea, and anthropogenic and human activity is what causes the concentration of ethyl methyl sulphide. Because it releases sulfuric oxides into the air, methyl ethyl sulphides are bad for the atmosphere. To understand the fate of methyl ethyl sulfide's oxidation products in the atmosphere, it is useful to investigate these compounds. The goal of this research is to use thermodynamic data to identify the byproducts of methyl ethyl sulphide oxidation under normal circumstances and at various temperatures. For all potential routes for the oxidation of radicals from methyl ethyl sulphide, Entropy and the change in Gibb's free energy were calculated. Additionally, the enthalpy change for the chemical routes was calculated, and the outcomes were contrasted with those attained using the CBS-QB3 DFT method. According to research, ethyl methyl sulphide may be oxidised to produce acetaldehyde (CH3CH=O), thioformaldehyde (CH2=S), thio-acetaldehyde (CH3CH=S), and formaldehyde (CH2=O) at typical circumstances of 298 K and 1 atm pressure.

Author(s) Details:

Hebah Abdel-Wahab,
Delaware County College, 901 Media Line Rd, Media, PA 19063, USA.

Tamara Gund,
New Jersey Institute of Technology, Newark NJ 07102, USA.

Please see the link here: https://stm.bookpi.org/CTCB-V3/article/view/7495

Thermodynamic Equation of the Pedostructure Hydric Conductivity | Chapter 1 | Research Developments in Science and Technology Vol. 8

The dynamics of water in a soil pedostructure sample whose interior environment is exposed to a potential gradient caused by the evaporation of water from the surface is the topic of this article. The findings and recommendations of a basic theoretical investigation into the molecular thermodynamic equilibrium of the two aqueous phases of the soil pedostructure are the exclusive subject of this paper. In this article, the systemic paradigm of hydrostructural pedology serves as a reminder of the novel ideas and descriptive variables of the hydro-thermodynamic equilibrium state of the soil medium that were established at the molecular level of the fluid phases of the pedostructure (water and air) in a previous article. They go beyond the traditional mono-scale description of soil water dynamics and provide access to the molecular description of water movement in the soil pedostructure. We have specifically examined and physically defined the water flux in the soil pedostructure at its three levels of organisational scale: the Eulerian flux at the macroscopic level of the entire pedostructure sample, the real flux of the two aqueous phases of the pedostructure through the inter primary-aggregates space, and the molecular flux of the mobile aqueous phase in the inter primary-aggregates space. For each of these fluxes at each of the three scale levels, the continuity equation can be written, and it is this continuity equation that establishes the space/time ratio required to construct the thermodynamic equation for water conductivity. The experimental findings completely support the theory, supporting the framework's systematic approach in the process.

Author(s) Details:

Erik Braudeau,

IRD, Institut de Recherche pour le Développement, France and Valorhiz - Parc scientifique Agropolis, F34980 Montferrier sur Lez, France.

Rabi H. Mohtar,

Faculty of Agricultural and Food Sciences, American University of Beirut, Lebanon and Department Biological and Agricultural Engineering (BAEN), Zachry Department Civil and Environmental Engineering (CVEN), Texas A&M University, USA.

Please see the link here: https://stm.bookpi.org/RDST-V8/article/view/7394