LNAPL transmissivity is the discharge of light non-aqueous phase liquid (LNAPL) through a unit width of aquifer for a unit gradient.
An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials. Groundwater can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, which is a bed of low permeability along an aquifer, and aquiclude, which is a solid, impermeable area underlying or overlying an aquifer. If the impermeable area overlies the aquifer, pressure could cause it to become a confined aquifer.
Scholars Alex Mayer and S. Majid Hassanizadeh define LNAPL transmissivity as the "product of the porous medium permeability and the LNAPL relative permeability, which in turn is a function of saturation, and the thickness of the LNAPL". They wrote that once LNAPL is taken away, a lower recovery rate occurs because the "saturation and thickness of the mobile LNAPL fraction decreases". [1]
LNAPL transmissivity is a summary parameter that takes into account soil type and physical properties (e.g., porosity and permeability), LNAPL physical fluid properties(e.g., density and viscosity) and LNAPL saturation (i.e., amount of LNAPL present within the pore network). Consequently, LNAPL transmissivity is comparable across soil types, LNAPL types and recoverable LNAPL volumes. More importantly, for LNAPL recovery from a given well, the soil and LNAPL physical properties do not change significantly through time. What changes, is the LNAPL saturation (amount of LNAPL present). As a result, LNAPL transmissivity decreases in direct proportion to the decrease in LNAPL saturation achievable through liquid recovery technology. LNAPL Transmissivity is not the only piece of data required when evaluating a site overall, because it requires a good LNAPL conceptual model in order to calculate. However, it is a superior summary metric to gauged LNAPL thickness to represent LNAPL recoverability and migration risk (e.g., on site maps) and direct remediation efforts. [2]
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
In chemistry, a solution is a special type of homogeneous mixture composed of two or more substances. In such a mixture, a solute is a substance dissolved in another substance, known as a solvent. The mixing process of a solution happens at a scale where the effects of chemical polarity are involved, resulting in interactions that are specific to solvation. The solution assumes the phase of the solvent when the solvent is the larger fraction of the mixture, as is commonly the case. The concentration of a solute in a solution is the mass of that solute expressed as a percentage of the mass of the whole solution. The term aqueous solution is when one of the solvents is water.
Solubility is the property of a solid, liquid or gaseous chemical substance called solute to dissolve in a solid, liquid or gaseous solvent. The solubility of a substance fundamentally depends on the physical and chemical properties of the solute and solvent as well as on temperature, pressure and presence of other chemicals of the solution. The extent of the solubility of a substance in a specific solvent is measured as the saturation concentration, where adding more solute does not increase the concentration of the solution and begins to precipitate the excess amount of solute.
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In multiphase flow in porous media, the relative permeability of a phase is a dimensionless measure of the effective permeability of that phase. It is the ratio of the effective permeability of that phase to the absolute permeability. It can be viewed as an adaptation of Darcy's law to multiphase flow.
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The presence of ethanol can lead to the formations of non-lamellar phases also known as non-bilayer phases. Ethanol has been recognized as being an excellent solvent in an aqueous solution for inducing non-lamellar phases in phospholipids. The formation of non-lamellar phases in phospholipids is not completely understood, but it is significant that this amphiphilic molecule is capable of doing so. The formation of non-lamellar phases is significant in biomedical studies which include drug delivery, the transport of polar and non-polar ions using solvents capable of penetrating the biomembrane, increasing the elasticity of the biomembrane when it is being disrupted by unwanted substances and functioning as a channel or transporter of biomaterial.
Seyed Majid Hassanizadeh is a professor of hydrogeology at Utrecht University, where he heads the Hydrogeology group at the Faculty of Geosciences. He also is a senior advisor with the Soil and Groundwater Department of Deltares. His research focuses on flow of fluids and transport of solutes and colloids in porous media, through theory development, experimental studies, and modeling work. In particular, he focuses on two-phase flow, reactive transport in variably-saturated porous media, transport of micro-organisms, and biodegradation.
A tunable metamaterial is a metamaterial with a variable response to an incident electromagnetic wave. This includes remotely controlling how an incident electromagnetic wave interacts with a metamaterial. This means the capability to determine whether the EM wave is transmitted, reflected, or absorbed. In general, the lattice structure of the tunable metamaterial is adjustable in real time, making it possible to reconfigure a metamaterial device during operation. It encompasses developments beyond the bandwidth limitations in left-handed materials by constructing various types of metamaterials. The ongoing research in this domain includes electromagnetic materials that are very meta which mean good and has a band gap metamaterials (EBG), also known as photonic band gap (PBG), and negative refractive index material (NIM).
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