Understanding the relationship between meltwater discharge and solute concentration by modeling solute transport in a snowpack in snow-dominated regions – A review

Polar Science ◽  
2021 ◽  
pp. 100782
Author(s):  
Jeonghoon Lee ◽  
Hyejung Jung
Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 839
Author(s):  
Michael Miles ◽  
Biddut Bhattacharjee ◽  
Nakul Sridhar ◽  
Apresio Kefin Fajrial ◽  
Kerri Ball ◽  
...  

In recent years, microfluidic devices have become an important tool for use in lab-on-a-chip processes, including drug screening and delivery, bio-chemical reactions, sample preparation and analysis, chemotaxis, and separations. In many such processes, a flat cross-sectional concentration profile with uniform flow velocity across the channel is desired to achieve controlled and precise solute transport. This is often accommodated by the use of electroosmotic flow, however, it is not an ideal for many applications, particularly biomicrofluidics. Meanwhile, pressure-driven systems generally exhibit a parabolic cross-sectional concentration profile through a channel. We draw inspiration from finite element fluid dynamics simulations to design and fabricate a practical solution to achieving a flat solute concentration profile in a two-dimensional (2D) microfluidic channel. The channel possesses geometric features to passively flatten the solute profile before entering the defined region of interest in the microfluidic channel. An obviously flat solute profile across the channel is demonstrated in both simulation and experiment. This technology readily lends itself to many microfluidic applications which require controlled solute transport in pressure driven systems.


2020 ◽  
Vol 117 (38) ◽  
pp. 23443-23449 ◽  
Author(s):  
Sharul Hasan ◽  
Vahid Niasar ◽  
Nikolaos K. Karadimitriou ◽  
Jose R. A. Godinho ◽  
Nghia T. Vo ◽  
...  

Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 μm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (>50 TB) was produced, while imaging the evolution of the solute concentration with time at any given point within the field of view. We show that the fluids’ topology has a critical signature on the non-Fickian transport, which yet needs to be included in the Darcy-scale solute transport models. The three-dimensional (3D) results show that the fully mixing assumption at the pore scale is not valid, and even after injection of several pore volumes the concentration field at the pore scale is not uniform. Additionally, results demonstrate that dispersivity is changing with saturation, being twofold larger at the saturation of 0.52 compared to that at the fully saturated domain.


2006 ◽  
Vol 70 (5) ◽  
pp. 865-871 ◽  
Author(s):  
P. Komlosi ◽  
A. Fintha ◽  
P.D. Bell

2021 ◽  
Vol 249 ◽  
pp. 09002
Author(s):  
Iván Colecchio ◽  
Natalia Arze ◽  
Georgina Flores ◽  
Ana Quijandria ◽  
Alejandro Boschan

The transport of a colouring solute, driven by the buoyant displacement of microscopic suspended particles, and in the absence of net flow, is studied experimentally in a Hele Shaw cell. Initially, a sharp interface between a transparent fluid without particles and an underlying coloured suspension is obtained. From this situation, the suspended particles rise, carrying the solute in the form of a fingering instability across the interface, where a light transmission technique is used to measure the local solute concentration. This one attains an asymptotic value that increases with the solid fraction ϕ of suspended particles, and decreases with the distance to the interface. The solute mass discharge also increases with ϕ, always being relatively small (< 3%). The onset and development of the instability as the mechanism driving the transport of the solute is discussed.


1986 ◽  
Vol 250 (1) ◽  
pp. F97-F102
Author(s):  
Y. Takamitsu ◽  
R. T. Kunau

Administration of indomethacin or meclofenamate to normal rats increases renal papillary solute concentration primarily by enhancing solute addition. A reduction in papillary solute concentration is characteristic of potassium deficiency. Of the multiple factors probably responsible for this reduction, several can be influenced by indomethacin or meclofenamate. The present study examined the effect of indomethacin on papillary solute concentration in the potassium-deficient rat. Indomethacin increased papillary solute concentration in normal but not potassium-deficient rats when studied in the conscious hydropenic state. Since indomethacin could increase papillary plasma flow in the potassium-deficient rat, potentially negating any enhancement of solute transport into the papilla, papillary plasma flow and papillary Cl concentration were determined in anesthetized surgically manipulated rats. Base-line papillary Cl concentrations were reduced in this setting. Indomethacin increased papillary plasma flow only in potassium-deficient rats but increased papillary Cl concentration equivalently in normal and potassium-deficient rats. The ability of indomethacin to increase papillary solute concentration in the potassium-deficient rat seemingly depends upon the experimental setting.


Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1028
Author(s):  
Bakhtiyor Khuzhayorov ◽  
Jabbor Mustofoqulov ◽  
Gafurjan Ibragimov ◽  
Fadzilah Md Ali ◽  
Bekzodjon Fayziev

In this paper, the problem of solute transport in a fractured-porous medium taking into account the non-equilibrium adsorption kinetic is studied. The solute transport in fractured-porous medium consisting of two fractures and a porous block between them located in a symmetric form is considered. The problem is then solved numerically by using the finite difference method. Based on the numerical results, the solute concentration and adsorption fields in the fractures and porous blocks are shown in graphical form. The effect of adsorption on the solute transport in a fractured-porous medium is then analyzed. In the case of different parameters in two zones, asymmetric distribution of the solute concentration and adsorption is obtained. The nonlinear kinetics of adsorption leads to an increase in the adsorption effects, conversely slowing down the rate of the distribution of concentration of the solute in the fluid.


2019 ◽  
Vol 8 (2) ◽  
pp. 3541-3544

In this paper, the solution of the advection-dispersion equation with different sorption values is used for the prediction of solute concentration in groundwater. Sorption process in the groundwater is complex, due to increasing the groundwater pollution the effect of different chemical transport plotted. The fate and sorption process of different chemical different degradation constant. We used the analytical solution to evaluate the transport phenomenon and analysis of the chemical dissolved in groundwater. The solute transport model simulated with the analytical solution and final result obtained using MATLAB software. The solution of a test problem based on the sequential degradation of the different chemical in the groundwater. This solution of equilibrium and rate of sorption dynamics of processes is imperative for accurate fate and transport modeling. The present study shows the effects of advection, dispersion/diffusion, and sorption equation on the saturated media of soil. MATLAB software used for analyzing the solution of groundwater and showing the different case taking care of saturated aquifer and with different void ratio of soil its shows that the soil parameter is also impotent parameter and its effect can see in plot between concertation vs time. The solute transport model simulated with the analytical solution and final result obtained using MATLAB software. The solution of a test problem based on the sequential degradation of the different chemical in the groundwater. This study compares the solute concentration with respect to distance and its different hydraulics conductivity of dense sad and lose.


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