Formation Of Concentration Gradient Research Articles

Exploring the Synergistic Effects of Dual‐Layer Electrodes for High Power Li‐Ion Batteries

AbstractThe electrification of the transport sector has created an increasing demand for lithium‐ion batteries that can provide high power intermittently while maintaining a high energy density. Given the difficulty in designing a single redox material with both high power and energy density, electrodes based on composites of several electroactive materials optimized for power or capacity are being studied extensively. Among others, fast‐charging LiFePO4 and high energy Li(NixMnyCoz)O2 are commonly employed in industrial cell manufacturing. This study focuses on comparing different approaches to combining these two active materials into a single electrode. These arrangements were compared using standard electrochemical (dis)charge procedures and using synchrotron X‐ray fluorescence to identify variations in solution concentration gradient formation. The electrochemical performance of the layered electrodes with the high‐power material on top is found to be enhanced relative to its blended electrode counterpart when (dis)charged at the same specific currents. These findings highlight dual‐layer lithium‐ion batteries as an inexpensive way of increasing energy and power density of lithium‐ion batteries as well as a model system to study and exploit the synergistic effects of blended electrodes.

Co-feeding strategy alleviates hypoxic stress in large-scale bioreactor for optimal production of secretory recombinant proteins in Pichia pastoris.

The loss of mixing efficiency inherent to bioreactor process operated at large-scale yields to the formation of concentration gradient and thus to heterogeneous culture conditions. For processes operated with methanol feeding, P. pastoris faces oscillatory culture conditions that significantly affect the cell ability to produce secretory recombinant proteins at high yield. Extended cell residence time in microenvironments of high methanol concentration and low oxygen availability that are typically found in the upper part of the bioreactor near the feeding point, triggers the unfolded protein response (UPR) and thus impairs proper protein secretion. Methanol co-feeding with sorbitol was shown herein to reduce the UPR response and to restore productivity of secreted protein.

Analysis of Continuous Bioadsorptive Removal of Cadmium in the Light of Circular Economy and Sustainability

The presented study is an experimentation on bioadsorption of cadmium on lentil husk (LH) stacked in fixed bed column reactor. Here the concept of circular economy is integrated to demonstrate its compliance with biological adsorption. In addition sustainability evaluation of the work has been done with respect to environmental, economical and executional procedure. As regard to experimentation adsorption capacity, percentage adsorption and breakthrough time all found to be dependent on the variation of design parameters. Sorbate (cadmium) concentration in treated effluents was inversely proportional to bed height and directly related to flow rate owing to prolonged interaction with metal binding sites. Adsorption capacity (164.25 mg g−1) peaked up at highest feed concentration due to formation of concentration gradient, overcoming the resistance offered during transfer of solute. Desorption was fruitful (up to ~96%) and the fixed bed regained its performing capacity successively. Industrial effluents were reclaimed with high accuracy for considerable duration.

Fast Determination of the Limiting Ionic Diffusion Coefficient in Lithium Metal Polymer Batteries

The energy conversion and its storage is a tremendous challenge for our society. Despite the great progress of the Lithium (Li)-ion technology based on flammable liquid electrolyte, their intrinsic instability is a strong safety issue for large-scale applications. The use of solid polymer electrolytes (SPEs) is an adequate solution in terms of safety and energy density thanks to their stability towards Li metal.[1] Moreover, as for conventional liquid electrolyte, the cationic transference number of poly(ethylene oxide) based SPE is typically below 0.2 which limits their power performance due to the formation of concentration gradient throughout the electrodes.[2] In such Li metal battery, the SPE acts as both separator and functionalized cathode binder ensuring ionic transport all over the battery. To increase the battery energy density a simple way is to use thicker cathode. Indeed, for a given electrode formulation, the energy density is directly linked to the active material loading.[3]The goal of this study is to propose a quick and efficient methodology to optimize the thickness of the SPE and of the cathode based on charge transport parameters, which allows to determine the effective limiting Li+ diffusion coefficient. Revisiting a protocol by Doyle et al.[4] the battery power performance is rapidly established, at least 8 time faster than conventional cycling (charge-discharge steps) with a similar accuracy as depicted in Figure 1.[5] Then, by using an approach based on the Sand equation a limiting current density is determined. A unique mother curve of the capacity as a function of the limiting current density is obtained whatever the electrode and electrolyte thicknesses. Finally, the effective limiting diffusion coefficient is estimated which in turn allows to design the best electrode depending on electrolyte thickness.

Operando Tracking of Solution-Phase Concentration Profiles in Li-Ion Battery Positive Electrodes Using X-ray Fluorescence.

The trade-off between energy density and power capabilities is a challenge for Li-ion battery design as it highly depends on the complex porous structures that holds the liquid electrolyte. Specifically, mass-transport limitations lead to large concentration gradients in the solution-phase and subsequently to crippling overpotentials. The direct study of these solution-phase concentration profiles in Li-ion battery positive electrodes has been elusive, in part because they are shielded by an opaque and paramagnetic matrix. Herein we present a new methodology employing synchrotron hard X-ray fluorescence to observe the concentration gradient formation within Li-ion battery electrodes in operando. This methodology is substantiated with data collected on a model LiFePO4/Li cell using a 1 M LiAsF6 in 1:1 ethylene carbonate/dimethyl carbonate (EC/DMC) electrolyte under galvanostatic and intermittent charge profiles. As such, the technique holds great promise for optimization of new composite electrodes and for numerical model validation.

Operando detection of single nanoparticle activity dynamics inside a model pore catalyst material.

Nanoconfinement in porous catalysts may induce reactant concentration gradients inside the pores due to local conversion. This leads to inefficient active material use since parts of the catalyst may be trapped in an inactive state. Experimentally, these effects remain unstudied due to material complexity and required high spatial resolution. Here, we have nanofabricated quasi-two-dimensional mimics of porous catalysts, which combine the traits of nanofluidics with single particle plasmonics and online mass spectrometry readout. Enabled by single particle resolution at operando conditions during CO oxidation over a Cu model catalyst, we directly visualize reactant concentration gradient formation due to conversion on single Cu nanoparticles inside the "model pore" and how it dynamically controls oxidation state-and, thus, activity-of particles downstream. Our results provide a general framework for single particle catalysis in the gas phase and highlight the importance of single particle approaches for the understanding of complex catalyst materials.

Concentration Gradient Constructions Using Inertial Microfluidics for Studying Tumor Cell-Drug Interactions.

With the continuous development of cancer therapy, conventional animal models have exposed a series of shortcomings such as ethical issues, being time consuming and having an expensive cost. As an alternative method, microfluidic devices have shown advantages in drug screening, which can effectively shorten experimental time, reduce costs, improve efficiency, and achieve a large-scale, high-throughput and accurate analysis. However, most of these microfluidic technologies are established for narrow-range drug-concentration screening based on sensitive but limited flow rates. More simple, easy-to operate and wide-ranging concentration-gradient constructions for studying tumor cell–drug interactions in real-time have remained largely out of reach. Here, we proposed a simple and compact device that can quickly construct efficient and reliable drug-concentration gradients with a wide range of flow rates. The dynamic study of concentration-gradient formation based on successive spiral mixer regulations was investigated systematically and quantitatively. Accurate, stable, and controllable dual drug-concentration gradients were produced to evaluate simultaneously the efficacy of the anticancer drug against two tumor cell lines (human breast adenocarcinoma cells and human cervical carcinoma cells). Results showed that paclitaxel had dose-dependent effects on the two tumor cell lines under the same conditions, respectively. We expect this device to contribute to the development of microfluidic chips as a portable and economical product in terms of the potential of concentration gradient-related biochemical research.

Imaging the Solution Phase Concentration Gradient in Li-Ion Battery Positive Electrodes with X-Ray Fluorescence

With the current climate crisis having no end in sight, communities worldwide are depending on new battery technology to store energy from intermittent sources of energy such as wind and solar. Li-ion batteries (LIBs) have presented themselves as a worthy candidate for the task given their high capacity for charge as well as their durability in terms of cycle life. LIB models have been developed extensively for the purpose of understanding current behaviour and predicting future performance. A limiting factor in LIBs is the rate at which they can be (dis)charged which can be extensively hindered by the formation of a concentration gradient of Li+ within the positive and negative electrodes. Although the models that exist can predict what these gradients should be within the electrodes, there has, as of yet, been no experimental data representing the concentration gradient formation within the electrode pores. Using X-ray fluorescence (XRF) in conjunction with a synchrotron light source allows the spatially resolved observation of the Li+ concentration profile. This work can validate the predictive power of established P2D models in order to improve their accuracy in addition to serving as a screening technique for new composite positive electrodes. Figure 1

Fenofibrate Nanocrystal Composite Microparticles for Intestine-Specific Oral Drug Delivery System.

Hydrophobic drug nanocrystals (NCs) manufactured by particle engineering have been extensively investigated for enhanced oral bioavailability and therapeutic effectiveness. However, there are significant drawbacks, including fast dissolution of the nanocrystals in the gastric environment, leading to physicochemical instability. To solves this issue, we developed an innovative technique that involves the encapsulation of nanocrystals in composite spherical microparticles (NCSMs). Fenofibrate (FNB) NCs (FNB-NCs) manufactured by a wet stirred media milling (WSMM) technique and an ionotropic crosslinking method were used for FNB-NC encapsulation within gastroresistant NCSMs. Various solid-state methods were used for characterizing NCSMs. The pH-sensitive NCSMs showed a site-specific release pattern at alkaline pH and nearly 0% release at low pH (gastric environment). This phenomenon was confirmed by a real-time in situ UV-imaging system known as the surface dissolution imager (SDI), which was used to monitor drug release events by measuring the color intensity and concentration gradient formation. All these results proved that our NCSM approach is an innovative idea in oral drug delivery systems, as it resolves significant challenges in the intestine-specific release of hydrophobic drugs while avoiding fast dissolution or burst release.

Protein concentration gradients and switching diffusions.

Morphogen gradients play a vital role in developmental biology by enabling embryonic cells to infer their spatial location and determine their developmental fate accordingly. The standard mechanism for generating a morphogen gradient involves a morphogen being produced from a localized source and subsequently degrading. While this mechanism is effective over the length and time scales of tissue development, it fails over typical subcellular length scales due to the rapid dissipation of spatial asymmetries. In a recent theoretical work, we found an alternative mechanism for generating concentration gradients of diffusing molecules, in which the molecules switch between spatially constant diffusivities at switching rates that depend on the spatial location of a molecule. Independently, an experimental and computational study later found that Caenorhabditis elegans zygotes rely on this mechanism for cell polarization. In this paper, we extend our analysis of switching diffusivities to determine its role in protein concentration gradient formation. In particular, we determine how switching diffusivities modifies the standard theory and show how space-dependent switching diffusivities can yield a gradient in the absence of a localized source. Our mathematical analysis yields explicit formulas for the intracellular concentration gradient which closely match the results of previous experiments and numerical simulations.

A novel in vitro chemotaxis bioassay to assess the response of Meloidogyne incognita towards various test compounds.

Abstract Plant-parasitic, root-knot nematodes (Meloidogyne spp.) are a serious problem in agri- and horticultural crops worldwide. Understanding their complex host recognition process is essential for devising efficient and environmental-friendly management tactics. In this study, the authors report a new, simple, inexpensive, efficient, and quantitative method to analyze the chemotaxis of M. incognita second-stage juveniles (J2s) using a combination of pluronic gel and agar in a petri dish. The authors quantitatively defined the concentration gradient formation of acid fuchsin on the assay plate. Using this novel assay method, the authors have accurately measured the nematode response (attraction or repulsion) to various volatile (isoamyl alcohol, 1-butanol, benzaldehyde, 2-butanone, and 1-octanol) and non-volatile (root exudates of tomato, tobacco, and marigold) compounds. Isoamyl alcohol, 1-butanol, and 2-butanone were attractive to J2s through a broad range of concentrations. On the contrary, J2s were repelled when exposed to various concentrations of 1-octanol. Despite being attractive at lower concentrations, undiluted benzaldehyde was repulsive to J2s. Tomato and tobacco root exudates were attractive to J2s while marigold root exudates repelled J2s. The present quantitative assay method could be used as a reference to screen and identify new candidate molecules that attract or repel nematodes.

Multi-Temperature in Situ Magnetic Resonance Imaging of Polarization and Salt Precipitation in Li-Ion Battery Electrolytes

The parameterization and validation of robust electrochemical models for lithium-ion batteries in automotive applications, which are intended to address both the state of charge (SOC) and state of health (SOH) estimation problems, is an important milestone in their widespread deployment. Much effort has been focused on the mass transport characteristics of the electrode domains, but a significant fraction of overall polarization stems from concentration gradients that form in the electrolyte domain and their attendant effect on the mass transport parameters, which have recently been shown by in situ MRI to be quite significant, even within modest operational regimes.1 The effect of temperature on these concentration gradients remains to be explored by in situ MRI. The mass transport in the electrolyte domain is typically modelled as being governed by material balance of a binary salt in a concentrated solution, which can be realized by modifying the Nernst-Planck equation to have non-constant, concentration-dependent coefficients (Equation 1).2 This system has a steady-state concentration gradient (Equation 2) when migration flux driven by the potential and diffusion flux against the concentration gradient are in equilibrium (see Figure 1A). Using in situ MRI, the evolution of this gradient toward the steady-state upon constant-current charging can be monitored (Figure 1B). A surprising outcome of these studies was that at 10°C, an equal parts (v/v) mixture of EC/DEC with 1.00 M LiPF6 exhibited anomalous concentration gradient formation (Figure 2) with a current density corresponding to 6 A·m-2 (or ~C/4), whereas the same mixture and cell construction could be polarized without difficulty at room temperature. On comparing raw MR images from before the polarization and after the relaxation of the disrupted concentration gradient, it is clear that the overall signal intensity is lower whilst the shape of the profile is retained, which is a direct indicator that salt precipitation has occurred. There are two routes by which this salt precipitation phenomenon can be avoided: lowering the salt concentration, so that the absolute concentration at the upper portion of the gradient is decreased proportionately for an equivalent current density, and the selection of an electrolyte with better low-temperature solvation characteristics. Successful polarization and visualization of the electrolyte domain in situ was achieved with a 0.85 M variant of the equal-parts EC/DEC mixture utilized above, at a series of temperatures. This constitutes a means of avoiding the critical concentration at the low temperature where the 1.00 M variant exhibited precipitation, but it would come with a trade-off of reduced ionic conductivity. More significantly, a ‘full-strength’ 1.00 M LiPF6 in EC/PC/DMC, 5:2:3 (v/v) mixture was also successfully polarized at low, room, and elevated temperatures, with the same 6 A·m-2 applied current density. Previous ex situ experiments using the pulsed-field gradient NMR technique, in conjunction with conductivity measurements, had revealed that ion pairing at low temperature was significantly reduced in electrolyte mixtures where the fraction of high-dielectric solvent was maximized.3 A quantitative comparison of the steady-state concentration gradients at a series of inter-electrode distances and temperatures was also conducted with this electrolyte formulation, to assess how the magnitudes of the gradients varied with temperature, and to test the hypothesis inherent in Equation 2 that the inter-electrode spacing does not play a role in determining the magnitude of the steady-state gradient. Within 3σ confidence intervals, the inter-electrode spacing was not found to affect the inter-electrode spacing, which directly confirms that the in situ MRI technique can generate steady-state mass transport parameters which are relevant to real battery modelling efforts. A significant effect of the temperature on the magnitude of the steady-state concentration gradient is also illustrated in these multi-temperature imaging experiments, demonstrating the importance of characterizing the spatial variation and temperature-dependence of electrolyte mass transport characteristics for electrochemical model parameterization and validation. References (1) Krachkovskiy, S. A.; Bazak, J. D.; Werhun, P.; Balcom, B. J.; Halalay, I. C.; Goward, G. R. Visualization of Steady-State Ionic Concentration Profiles Formed in Electrolytes during Li-Ion Battery Operation and Determination of Mass-Transport Properties by in Situ Magnetic Resonance Imaging. J. Am. Chem. Soc. 2016, 138 (25), 7992–7999. (2) Sethurajan, A. K.; Krachkovskiy, S. A.; Halalay, I. C.; Goward, G. R.; Protas, B. Accurate Characterization of Ion Transport Properties in Binary Symmetric Electrolytes Using In Situ NMR Imaging and Inverse Modeling. J. Phys. Chem. B 2015, 119 (37), 12238–12248. (3) Krachkovskiy, S. A.; Bazak, J. D.; Fraser, S.; Halalay, I. C.; Goward, G. R. Determination of Mass Transfer Parameters and Ionic Association of LiPF 6 : Organic Carbonates Solutions. J. Electrochem. Soc. 2017, 164 (4), A912–A916. Figure 1

Aggregation-fragmentation model of robust concentration gradient formation

Concentration gradients of signaling molecules are essential for patterning during development and they have been observed in both unicellular and multicellular systems. In subcellular systems, clustering of the signaling molecule has been observed. We develop a theoretical model of cluster-mediated concentration gradient formation based on the Becker-Döring equations of aggregation-fragmentation processes. We show that such a mechanism produces robust concentration gradients on realistic time and spatial scales so long as the process of clustering does not significantly stabilize the signaling molecule. Finally, we demonstrate that such a model is applicable to the pom1p subcellular gradient in fission yeast.

Liquid gradient in two-dimensional matrix for high throughput screening.

Based on the ingenious combination of two different gradient generation mechanisms, this work reports a novel approach for a high throughput linear liquid gradient in a two-dimensional (2D) matrix. Specifically, a typical Christmas Tree structure with two inlets was designed as the first mixture gradient generator, upon which the second diffusion gradient generator was coupled to produce the desired concentration series on the basis of the distance difference. Rather than a simple 1D line, the integration of the two generators would result in an innovative 2D matrix of reservoirs, which was then characterized both theoretically and experimentally. Theoretically, calculation of fluid field demonstrated the formation of a concentration gradient, which was then confirmed by the dye solution visualization analysis. For high throughput screening application, doxorubicin (Dox) was then selected as model medicine to treat the acute myeloblastic leukemia (HL-60) cells. Cell viability displayed that cell death rate enhanced with the increase of drug concentration, and this result was higher than that on a 96-well plate, and the corresponding mechanism was properly discussed. Subsequently, Dox and quercetin were employed simultaneously to generate an overlapping gradient and its effect on HL-60 cells was investigated. Due to the automatic formation of concentration gradient that could improve the work efficiency, this work provides a promising tool for future high throughput drug screening.

Development and roles of ciliated cells during neurogenesis

Event Abstract Back to Event Development and roles of ciliated cells during neurogenesis Nathalie Spassky1* 1 UPMC, Hospital Salpetriere, INSERM U-711, France Neural stem cells (NSCs) persist in the mammalian brain throughout life. These cells occasionally contact the ventricle and display a primary cilium. We have recently shown that it is required for NSCs proliferation in response to Sonic Hedgehog in the cerebellum and hippocampus. We are now studying its putative role in the developing cortex. Ependymal cells are multiciliated cells lining the walls of all brain ventricles. In the adult, these cells play essential roles in brain homeostasis and in the transport of cerebrospinal fluid (CSF). Moreover, beating of ependymal cilia is also required for concentration gradient formation of CSF guidance molecules and directional migration of neuroblasts from the walls of the lateral ventricles to the olfactory bulb. During brain development, these cells are derived from radial glial cells at embryonic stages and do not regenerate in case of injury. Our goal is to identify the mechanisms of ependymal cells differentiation from neural stem cells and to better understand how such a polarized epithelium is formed during development. Conference: 3rd Mediterranean Conference of Neuroscience , Alexandria, Egypt, 13 Dec - 16 Dec, 2009. Presentation Type: Oral Presentation Topic: Symposium 03 – Cellular regulation of adult-born neurons and their stem cells Citation: Spassky N (2009). Development and roles of ciliated cells during neurogenesis. Front. Neurosci. Conference Abstract: 3rd Mediterranean Conference of Neuroscience . doi: 10.3389/conf.neuro.01.2009.16.014 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Nov 2009; Published Online: 18 Nov 2009. * Correspondence: Nathalie Spassky, UPMC, Hospital Salpetriere, INSERM U-711, Paris, France, nathalie.spassky@upmc.fr Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nathalie Spassky Google Nathalie Spassky Google Scholar Nathalie Spassky PubMed Nathalie Spassky Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

New Neurons Follow the Flow of Cerebrospinal Fluid in the Adult Brain

In the adult brain, neuroblasts born in the subventricular zone migrate from the walls of the lateral ventricles to the olfactory bulb. How do these cells orient over such a long distance and through complex territories? Here we show that neuroblast migration parallels cerebrospinal fluid (CSF) flow. Beating of ependymal cilia is required for normal CSF flow, concentration gradient formation of CSF guidance molecules, and directional migration of neuroblasts. Results suggest that polarized epithelial cells contribute important vectorial information for guidance of young, migrating neurons.

Formation of concentration gradient and its application to DNA capillary electrophoresis

A new method to introduce the concentration gradient into the capillary has been developed and its application to DNA capillary electrophoresis is presented. The concentration gradient produced by mixing 5% w/v polyacrylamide-co-poly(N-dimethylacrylamide) (PAM-co-PDMA) solution and 1 × Tris/N-tris(hydroxymethyl)methyl-3-amino-propanesulfonic acid/EDTA (TT) + 5 M urea buffer was successfully achieved by using two programmable syringe pumps with strict control of dead volume, flow rate, and pressure balance. This method has the advantages of high stability, reproducibility, and versatility. The column with concentration gradient greatly improved the resolution, especially for the large DNA fragments, due to a decrease in band width broadening with time. A column containing 2—4% w/v gradient in four steps had a longer read length, shorter separation time and better resolution (after 380 base) than that of 4% w/v single concentration polymer solution. The number of steps in the gradient had almost no effect on the performance. The change in the average concentration by relocating the position of the same step gradient, i.e., a combination of different low concentration to high concentration polymer solution ratios, resulted in a different migration time, read length and resolution.

Formation of concentration gradient and its application to DNA capillary electrophoresis.

A new method to introduce the concentration gradient into the capillary has been developed and its application to DNA capillary electrophoresis is presented. The concentration gradient produced by mixing 5% w/v polyacrylamide-co-poly(N-dimethylacrylamide) (PAM-co-PDMA) solution and 1 x Tris/N-tris(hydroxymethyl)methyl-3-amino-propanesulfonic acid/EDTA (TT) + 5 M urea buffer was successfully achieved by using two programmable syringe pumps with strict control of dead volume, flow rate, and pressure balance. This method has the advantages of high stability, reproducibility, and versatility. The column with concentration gradient greatly improved the resolution, especially for the large DNA fragments, due to a decrease in band width broadening with time. A column containing 2-4% w/v gradient in four steps had a longer read length, shorter separation time and better resolution (after 380 base) than that of 4% w/v single concentration polymer solution. The number of steps in the gradient had almost no effect on the performance. The change in the average concentration by relocating the position of the same step gradient, i.e., a combination of different low concentration to high concentration polymer solution ratios, resulted in a different migration time, read length and resolution.

Effect of Segregation on the Heterogeneous Kinetics at the Oxygen/Zirconia Interface

This paper considers the effect of the segregation-induced concentration gradients and related electric fields on the transport across the oxygen/zirconia interface. Specifically, this paper considers yttrium segregation in yttria-stabilized zirconia and its effect on the formation of concentration gradient in the interface layer.

Gravity induced formation of concentration gradients in supersaturated binary solutions

Experimental and theoretical studies of the formation of solute concentration gradient in supersaturated binary solutions in a gravitational field were carried out. The formation of solute concentration gradient was associated with the gravity induced redistribution of subcritical solute clusters. The birth-death process of the new solute-rich phase domains (subcritical solute clusters) was described in terms of the time-dependent Ginzburg-Landau model developed for metastable state relaxation in binary (solute + solvent) non-critical solutions in the presence of a gravitational field. A new mathematical Ansatz was developed for solution of the model equations. This Ansatz has allowed to approach for the first time the following important problems: 1. (A) Microstructure of solute distribution inside of the subcritical solute clusters. The analytical results obtained demonstrate that solute inside of the subcritical solute clusters is heterogeneously distributed with a spatially periodic structure. 2. (B) Macrostructure of the solute subcritical clusters distribution in a gravitational field. The subcritical solute clusters are found to be distributed heterogeneously in a gravitational field. This heterogeneity, which is due to the heterogeneous birth-death process of the subcritical solute clusters in a gravitational field, initiates a noticeable solute concentration gradient in vertical columns of supersaturated binary solutions. An analysis and comparison of theoretical results and experimental data related to the solute concentration gradient formation in a gravitational field are presented. It is also demonstrated that the critical radius of solute clusters (radius of nucleation) and induction time are gravity-dependent.