Mixing Behavior Research Articles

Order-based structure learning without score equivalence

Summary We propose an empirical Bayes formulation of the structure learning problem, where the prior specification assumes that all node variables have the same error variance, an assumption known to ensure the identifiability of the underlying causal directed acyclic graph. To facilitate efficient posterior computation, we approximate the posterior probability of each ordering by that of a best directed acyclic graph model, which naturally leads to an order-based Markov chain Monte Carlo algorithm. Strong selection consistency for our model in high-dimensional settings is proved under a condition that allows heterogeneous error variances, and the mixing behaviour of our sampler is theoretically investigated. Furthermore, we propose a new iterative top-down algorithm, which quickly yields an approximate solution to the structure learning problem and can be used to initialize the Markov chain Monte Carlo sampler. We demonstrate that our method outperforms other state-of-the-art algorithms under various simulation settings, and conclude the paper with a single-cell real-data study illustrating practical advantages of the proposed method.

Studying the Transmission Behavior of Two-Phase Flow Oil-Water Mixing Using a Laboratory Multiple Porous Media Model

The formation and flow of emulsions in porous media are common to all technologies used to extract or process oil. In most cases, oil and water emulsions are formed in a porous medium due to oil spills near watery areas or soils containing water. This emulsion leads to a reaction between oil and water, which finds its way to the porous medium. The detailed flow mechanisms of emulsions through porous media are not well understood. In this study, the soil’s oil percentage variation was studied when sand was introduced or an emulsion, i.e., mixed with water, and two porous media, different in composition and physical properties, were used to find out their effect on oil transmission. The percentage of oil and water was calculated at several points at different distances and times. It was noted that the results differed in both mediums due to the difference in permeability, porosity, arrangement of soil particles, compaction process, and other physical properties. Liquids’ viscosity, density, and chemical composition clearly and significantly affect the results. The time for the oil to reach the last point in the pipe differed for both soils. If the time period in the experiment of pumping oil only in sandy soil took 6 hours and the washing process took 3 hours. In organic soil, the time period for the pollutant pumping stage took about 7 hours and the washing stage about 4 hours because the oil is transmitted in sandy soil is faster, but in the experiment of pumping oil and water together, the time period in the process of pumping oil and water together in sandy soil took 4 hours and the washing process 3 hours In organic soil, the period of pumping oil and water together took 5 hours, and the washing period 3 hours, because the percentage of oil was less than in the experiment of pumping oil only. In the soil, that is, if the period of pumping the pollutant increased for more than 15 hours, the oil may reach a distance of more than 4 meters in the soil. As for the washing process, when the oil is mixed with water, it gives better results when washing it than if the oil enters alone into the soil because the proportions of oil when it enters the soil together with the water, it is little and does not rise much, so it is easy to wash.

Structural Analysis of the Gd-Au-Al 1/1 Quasicrystal Approximant Phase across Its Composition-Driven Magnetic Property Changes.

Gd14AuxAl86-x Tsai-type 1/1 quasicrystal approximants (ACs) exhibit three magnetic orders that can be finely tuned by the valence electron concentration (e/a ratio). This parameter has been considered to be crucial for controlling the long-range magnetic order in quasicrystals (QCs) and ACs. However, the nonlinear trend of the lattice parameter as a function of Au concentration suggests that Gd14AuxAl86-x 1/1 ACs are not following a conventional solid solution behavior. We investigated Gd14AuxAl86-x samples with x values of 52, 53, 56, 61, 66, and 73 by single-crystal X-ray diffraction. Our analysis reveals that increasing Au/Al ordering with increasing x leads to distortions in the icosahedral shell built of the Gd atoms and that trends observed in the interatomic Gd-Gd distances closely correlate with the magnetic property changes across different x values. Our results demonstrate that the e/a ratio alone may be an oversimplified concept for investigating the long-range magnetic order in 1/1 ACs and QCs and that the mixing behavior of the nonmagnetic elements Au and Al plays a significant role in influencing the magnetic behavior of the Gd14AuxAl86-x 1/1 AC system. These findings will contribute to improved understanding towards tailoring magnetic properties in emerging materials.

Controlling the structure of spin-coated multilayer ethylcellulose/hydroxypropylcellulose films for drug release

Porous phase-separated ethylcellulose/hydroxypropylcellulose (EC/HPC) films are used to control drug transport out of pharmaceutical pellets. Water-soluble HPC leaches out and forms a porous structure that controls the drug transport. Industrially, the pellets are coated using a fluidized bed spraying device, and a layered film exhibiting varying porosity and structure after leaching is obtained. A detailed understanding of the formation of the multilayered, phase-separated structure during production is lacking. Here, we have investigated multilayered EC/HPC films produced by sequential spin-coating, which was used to mimic the industrial process. The effects of EC/HPC ratio and spin speed on the multilayer film formation and structure were investigated using advanced microscopy techniques and image analysis. Cahn-Hilliard simulations were performed to analyze the mixing behavior. A gradient with larger structures close to the substrate surface and smaller structures close to the air surface was formed due to coarsening of the layers already coated during successive deposition cycles. The porosity of the multilayer film was found to vary with both EC/HPC ratio and spin speed. Simulation of the mixing behavior and in situ characterization of the structure evolution showed that the origin of the discontinuities and multilayer structure can be explained by the non-mixing of the layers.

Comparison of non-reactive flow fields in conventional swirl-air combustion and swirl distributed combustion

Flow field distribution in traditional swirl flow and simulated distributed reaction swirl flow configuration was examined at 3 kHz frequency using high-speed Particle Image Velocimetry (PIV). Non-reactive flow field conditions in distributed reaction zones were fostered from the conventional swirl flow case using the designed inlet mixture preparation with CO2 dilution of the inlet airstream that corresponded to the combustion case at a heat release intensity of 5.72 MW/m3-atm. High-speed imaging of flow fields was performed at a framing rate of 3000 frames/s using a Neodymium-doped Yttrium Lithium Fluoride (Nd:YLF) laser beam at 527 nm wavelength to capture the Mie scattering images of the flow field. Mean flow velocity obtained from the post-processing of raw PIV images showed higher momentum flux injection in the swirl distributed flow zone case as compared to the normal swirl flow case. Enhanced velocity fluctuations were also observed in both the axial and radial direction for the distributed swirl flow case resulting in higher turbulence for the examined condition. The distributed swirl flow case showed a prominent corner recirculation zone along with higher flow entrainment within the recirculation zone. Enhanced interaction of average streamlines with vortices was found in the swirl distributed flow case. Increased turbulent fluctuation in the two different spatial directions was responsible for higher Reynolds stress distribution (u′v′) in the distributed flow case, indicating improved mixing behavior at lower global oxygen concentrations from the carbon dioxide (CO2) dilution, and showed different length scales of turbulent eddies. Furthermore, the spatial local Damkӧhler number values for distributed flow case (for its implication in reacting case) were found to be less than unity. The results showed a shorter flow timescale than the corresponding chemical timescales in distributed reaction zone. These results help support substantiating the difference of reaction regimes on the Borghi diagram (plot of velocity fluctuation/ laminar flame speed versus the integral length scale/ flame thickness) between the distributed reaction zone (that possesses thickened reaction zone) and conventional swirl reaction flow regimes having corrugated flamelet zone.

A case study of thermal mixing behavior of hot and cold fluid in T-junction with/without mixing jets

Three-dimensional numerical simulations are performed to study the turbulent mixing of hot and cold fluids at a T-junction with unique branch pipe extended mixing jets. The major aim of the current research is to compare the performance of two distinct designs for thermal mixing and flow characteristics of a T-junction. We investigate the effects of the momentum ratio and temperature difference of mixing fluids on temperature gradients for proposed configurations of T-junctions. The finding demonstrated that a T-junction with jets appears to mix hot and cold fluids more homogeneously. The addition of the mixing jets significantly lessens the internal wall's temperature gradients and improves the efficacy of thermal mixing. The thermal mixing efficiency for T-junctions with mixing jets increased by 25%, 42%, and 50%, respectively. At the same momentum ratio, the length of the thermal mixing in the T-junction with mixing jets is dramatically reduced by 77%, 79%, and 83%. The stress distribution is also determined using thermo-mechanical coupled analysis. The result shows the reduction in peak stresses substantially with the mixing jet T-junction. The current study will help the researcher to evaluate safety issues in high-temperature applications and better understand thermal mixing, flow characteristics, and thermal cracks.

Regulated vs. unregulated rivers: Impacts on CDOM dynamics in the eastern James Bay

The eastern James Bay (EJB) coast harbors numerous rivers, but there is a dearth of knowledge concerning dissolved organic matter (DOM) in the downstream coastal water. Here we report a four-year (2018–2021) and multi-seasons field study on the mixing behavior and characteristics of the chromophoric DOM (CDOM) in the nearshore EJB. Freshwater discharged from the extensively regulated La Grande River (LGR) was constantly depleted in DOM compared with the unregulated rivers (URRs), being on average 3.35 times lower in CDOM absorption coefficient at 440 nm (aCDOM(440)) and 2.50 times lower in dissolved organic carbon (DOC). In contrast, the absorption spectral slope between 275 and 295 nm (S275–295, a proxy of molecular weight) and the specific absorption coefficient at 254 nm (a*CDOM(254), an indicator of aromaticity) of the LGR CDOM were only 10.6% lower and 11.7% higher than those of the URRs CDOM, respectively. Riverine input was found to be the dominant source of CDOM in the study area, with little influence from sea ice formation or melting. CDOM distribution fell into two distinct regimes: the LGR-influenced low-CDOM area in the north and the URRs-influenced high-CDOM area in the south. The two areas showed strong conservative but separate aCDOM(440)–salinity relationships converging at a common marine endmember (salinity ∼25) with little seasonality. The composite data combing both areas and all seasons and years exhibited non-linear relationships between S275–295, a*CDOM(254) and aCDOM(440) and a robust simple linear correlation of DOC to aCDOM(440). This study suggests a strong impact of river regulation on CDOM input into the EJB, reveals low seasonal variability of CDOM mixing dynamics and characteristics, and demonstrates the feasibility of using remote sensing from space for real-time and synoptical assessment of DOM dynamics and the associated biogeochemical cycles in the EJB.

Three-dimensional flow structures and scalar mixing of a sand dune-inspired jet in crossflow

This paper performed particle image velocimetry (PIV) measurements and delayed detached-eddy simulations (DDES) to comprehensively investigate the flow and mixing behaviors of a sand dune(SD)-inspired JICF (jet in crossflow). PIV measurements were conducted in planes parallel to the mid-plane (Z/D = 0, 0.5, and 1), and three velocity ratios (VR = 0.4, 0.8, and 1.2) were studied. The time-averaged and turbulent flow features behind the sand dune-inspired JICF is strongly three-dimensional: the jet tends to move from the mid-plane to the outer planes and can stay attached well to the wall even at Z/D = 1. Then DDES method was applied to reveal detailed three-dimensional flow structures and mixing characteristics of the SD-inspired JICF, and a cylindrical JICF was also simulated as a benchmark for comparison. The horseshoe vortex, arch-shaped shear layer vortices, and streamwise rollers are mainly responsible for the formation of the anti-counter rotating vortex pair (anti-CRVP) observed in the mean flow field of SD configuration. Analysis of concentration distributions indicates that scalar mixing between the jet and the mainstream is highly correlated to the flow features and vortex structures, and the mixing strength of the sand dune-inspired JICF is generally weaker than that of the cylindrical JICF.

Using Data Assimilation to Improve Turbulence Modeling for Inclined Jets in Crossflow

Abstract Data assimilation (DA) integrating limited experimental data and computational fluid dynamics is applied to improve the prediction accuracy of flow and mixing behavior in inclined jet-in-crossflow (JICF). The ensemble Kalman filter (EnKF) approach is used as the DA technique, and the Reynolds-averaged Navier–Stokes (RANS) modeling serves as the prediction framework. The flow field and scalar mixing characteristics of a cylinder-inclined JICF and a sand dune (SD)-inspired inclined JICF are studied at various velocity ratios (VR = 0.4, 0.8, and 1.2). First, the Spalart–Allmaras (SA) model and the standard k-ɛ model are investigated based on the cylinder configuration at VR = 1.2. An optimized set of model constants are determined for each model using the EnKF-based data assimilation. The SA model shows remarkable improvement and better prediction in flow separation than the standard k-ɛ model after DA. Further exploration demonstrates that this set of the SA model constants can be extended to other VRs and even the SD-inspired configuration, mainly due to the correction of the predicted flow separation in inclined JICF. Finally, an investigation of the concentration field also shows satisfying improvement, resulting from a more appropriate turbulent Schmidt number. The optimized model constants, the revealed extensibility, and the uncovered mechanism of using the EnKF-based DA to improve the simulation of JICF could facilitate the design of related applications such as gas turbine film cooling.

Effect of Impeller Structure Parameters on Desulfurizer Mixing Behavior in KR Desulfurization Process

Effect of Impeller Structure Parameters on Desulfurizer Mixing Behavior in KR Desulfurization Process

Assessment of inlet mixing during charge and discharge of a large-scale water pit heat storage

Pit thermal energy storage (PTES) is an efficient renewable energy storage technology widely used in large-scale solar district heating systems. Accurate modeling of mixing in a PTES due to inlet flow is key in calculating heat storage performance. However, the commonly used one-dimensional PTES models fail to consider inlet mixing due to the three-dimensional nature of the mixing flow. This research adopts a three-dimensional model to analyze the dynamic behavior of inlet mixing inside the PTES. The model is validated against measurements of the Dronninglund PTES. To quantify the inlet mixing impact, two performance indicators (i.e., the penetration height (Z) and the energy distribution ratio (ηj)) are proposed. The parametric analysis revealed that Z is more dependent on the Reynold (Re) number than the Froude (Fr) number, while both the Re and Fr numbers influence ηj. According to the dimensional theory, the penetration height Z shows a power-law relation with time. For the energy distribution ratio ηj, a power-law relation with time is seen, although an asymptotic formula is needed in the region of a negative buoyancy jet. Finally, the inflow mixing inside the PTES is characterized under various operating conditions by empirical correlations. The results of this study could be used to improve the current one-dimensional heat storage models in terms of inlet mixing.

Positioning a Measurement System for Determining the Mixing Quality in Biogas Digesters

AbstractMixing quality in agricultural biogas plants is crucial for nutrition supply to the microorganisms and needs to be ensured by an energy‐efficient mixing strategy. Various approaches have been proposed to determine the mixing quality in biogas digesters. Among them are magnetic‐inductive or force sensors brought into vertical digesters through the concrete wall. This article presents an approach to locating these sensors effectively around the circumference of the digester to avoid positioning in dead zones and maximize information quality regarding flow and mixing behavior. Particle image velocimetry is used to measure flow fields in a transparent model digester. Finally, optimum measurement locations considering three widely used agitator geometries are suggested.

Influence of bed material on biomass gasification in fluidized beds via a TFM-DEM hybrid model

In the biomass gasification process, mixing and segregation behaviors of fuel particles and bed materials greatly influence the performance. In this work, the Two-Fluid Model-Discrete Element Method (TFM-DEM) hybrid model is employed to evaluate the impact of bed material on biomass gasification in a fluidized bed reactor, where fuel particles and bed material particles are described by the Lagrangian method and Eulerian method respectively. The biomass particle size distribution is taken into consideration. The kinetic theory of rough sphere (KTRS) is employed to consider the rotation impact of bed materials. Flow behaviors of binary mixture and gas composition distribution are analyzed. The results reveal that the bed materials with greater size can hinder the particle mixing behaviors and make the biomass particles concentrate on the bed surface so as to increase the non-uniformity of temperature distribution in the bed. A good fluidization with smaller bed material particles is beneficial to hydrogen production.

Influence of powder properties and mixing technique under different conditions, on the densification and thermal conductivity of AlN for solar thermal applications

In this study, a novel approach is presented which can be utilized to enhance the thermal conductivity and densification of sintered AlN pellets. AlN pellets with a CaO additive were produced by spark plasma sintering. The influence of CaO powder properties such as particle size (micron-, submicron- and nano-scale), dispersion, flowability and structural characteristics, on the mixing behavior of AlN and CaO mixed powders, and on the porosity and thermal conductivity of AlN pellets, were investigated. Additionally, the influence of mixing conditions, including additive content and rotational speed in a novel high-shear mixer (Picomix), were studied and various mixing techniques were compared. The results indicate that when the CaO content of the AlN pellets is increased to 3 wt%, their thermal conductivity rises from 48.1 W/m·K to 112.9 W/m·K. This increase can be attributed to the formation of a liquid phase, and to a reduction in pellet porosity during sintering. Furthermore, when the rotational speed of the mixer is increased to 5000 rpm, the pellets’ thermal conductivity further rises to 126.2 W/m·K. This improvement is a result of the enhanced dispersion of CaO in the mixed powder. The shearing forces in the Picomix facilitate the coating of AlN particles with submicron- or nano-scale CaO particles, thereby improving the flowability of the mixed powder and narrowing the particle size distribution. This further improves the liquid phase distribution, thus enhancing the thermal conductivity of the AlN pellets (135.3 W/m·K). The novel high-shear mixer (Picomix) has demonstrated enhanced performance when compared with traditional mixing techniques (ball milling and manual mixing), since it involves a solvent-free process, is faster, has a lower energy consumption, causes less powder-oxidation and leads to a higher value of thermal conductivity, making it an excellent choice for the preparation of mixed powders for solar thermal applications.

ENRM: An alternative tool for studying dynamical systems

In recent years, the recurrence plot technique has been increasingly used in nonlinear complex time series, to analyse the periodicity, chaos and non-stationarity. As far, some important methods have arisen based on the recurrence plot technique, among which the recurrence quantification analysis (RQA) is the most famous one, defined based on the recurrence matrix. As a tool of the RQA, the entropy based on recurrence microstates (ENRM), has been proposed in Corsoet al. (2018), to measure the chaotic and mixing behaviours of the underlying time series. In this paper, we first develop some techniques for more efficiently computing the ENRM. Another important contribution of this paper is to extend the concept of the ENRM to study multi-dimensional dynamical systems, where we regard each particle trajectory as a time series. This allows us to compare the ENRM to the finite time Lyapunov exponent (FTLE), which is another commonly used quantity for measuring chaotic behaviours of multi-dimensional dynamical systems. Examples will show different behaviours of particle trajectories with different magnitudes of ENRM values, and also the difference between the ENRM and the FTLE. Especially, by investigating a real data set, we show that the ENRM is a nice tool for measuring the complex behaviours of dynamical systems in the occasion where only sparse particle trajectories are provided.

Effects of rotation axis on mixing behavior of dissimilar particles in rotating drums

Particle segregation is a common phenomenon observed in rotating drums. This study found that the mixing of dissimilar particles in a rotating drum depended on the orientation of the rotation axis. When the rotation axis of the drum was selected to be perpendicular to the drum's own axis, two species of particles of different sizes mixed together. Numerical simulation study revealed that four counter convection flows formed in the drum. The movements of the small and large particles were similar in the cores of the convection zones but different in the vicinity of the free surface. The convection flows carried particles from the inner cores to the free surface. The difference in velocities between small and large particles in the vicinity of the free surface caused the particles to mix together. The finding of this study provides an alternative approach for the design of devices for mixing dissimilar particles.

Modelling and experimentation of a continuous nutrient recovery reactor – an assessment of mixing on reactor operation

Phosphorus recovery from human waste will help assure global food security, reduce environmental impact, and ensure effective stewardship of this limited and valuable resource. This can be accomplished by the precipitation of struvite (MgNH4PO4·6H2O) in a two-zone reactor, continuously fed with nutrient-rich hydrolysed urine and a magnesium solution. The solid struvite crystals are periodically “harvested”, removing accumulated crystal mass – and therefore recovered nutrients – from the process, and the operating campaign can, in principle, be continuously operated in a batch-continuous operating mode. A previously developed process model is augmented, incorporating two well-mixed volumes (upper zone and lower zone) that are coupled by intermixing forward and back flows. The intermixing back flow is parametrised and, therefore, adjusted for analysis. Crystal linear growth rate is modelled by a simple power-law kinetic, driven by the nutrient solution's saturation index (SI) of struvite. The instantaneous mass transfer rate of struvite constituents from liquid to solid phase is predicted, using the total interfacial area of the crystal population exposed to the well-mixed solution. This model describes a 12-L, laboratory reactor operated in the hybrid batch-continuous mode, although larger reactors could easily be accommodated, subject to their mixing behaviours. Experiments were performed at a 10-hour hydraulic residence time (HRT), which, importantly, is based on the volume of the well-mixed lower zone, since this is the volume of liquid that actively interacts with the suspended struvite crystals. The Mg/P feed molar ratio was varied (0.34, 0.64 and 1.29) to assess Mg feed rate-limiting behaviour. The concentration profiles of elemental P and Mg agree with experimentation, while P and Mg composition in the solid and X-ray diffraction support the production of struvite.

Utilizing Polyethylene Terephthalate PET in Concrete: A Review.

In general, plastic waste has been growing remarkably. Numerous waste plastic products are generated by manufacturing processes, service industries, and municipal solid waste (MSW). The increase in plastic waste increases concern about the environment and how to dispose of the generated waste. Thus, recycling plastic waste becomes an alternative technique to the disposal of plastic waste in a limited landfill. One of the solutions is to use plastic waste as recycled material in concrete construction to produce what is called green concrete. This research illustrates a summary of studies that utilized polyethylene terephthalate (PET) in concrete as a volume ratio or concrete aggregate replacement. It presents data with regard to mixing design and concrete behavior when PET is used. Moreover, using PET in concrete industries may reduce environmental pollution such as the emission of carbon dioxide and plastic waste disposal problems.

Non-conservative mixing behaviors of mercury in subterranean estuary: Coupling effect of hydrological and biogeochemical processes and implications for rapidly changing world

Coastal ecosystem is an important zone of mercury (Hg) storage and hotspot of neurotoxic methylmercury (MMHg) production and bioaccumulation. The releases of Hg from coastal aquifer or subterranean estuary (STE) via submarine groundwater discharge (SGD) to coastal waters provide an important source of Hg from land to seas. However, the transport and biogeochemical transformation of Hg in STEs are less quantified. In this study, we documented total Hg (THg) and MMHg dynamics in two distinct STEs (a sandflat at an open coast versus a mudflat at a bay) during two different seasons (December versus August) in the temperate coast of northern China, and further applied the salinity‐based conservative mixing model (CMM) to quantify the coupling effect of hydrological and biogeochemical processes on STE Hg cycle. Our field data presented large variations of THg and MMHg concentrations and%MMHg/THg of groundwater and sediment in both STEs over time and space. The CMM results clearly displayed substantial divergences of dissolved THg and MMHg from salinity in groundwater between sites and seasons, and the concentration and percent deviations in the Hg-rich mudflat were significantly higher than those in the Hg-poor sandflat. Our findings indicate the non-conservative mixing behaviors of Hg along the groundwater flow paths of both STEs, and the Hg-rich intertidal zone could be hotspot for the production and source of dissolved THg and MMHg to coastal waters via SGD. Our results provide field evidence to highlight that the hydrological shifts and biogeochemical processes collectively drive complex transport and biogeochemical transformation of Hg in STEs. The non-conservative mixing behaviors of Hg in STEs also highlight that, for more accurately calculating SGD-derived Hg fluxes to coastal seas, we need to carefully select the groundwater zonation of STE to better represent the output endmember. Our findings also address that human activities and climate change will profoundly alter the Hg biogeochemical cycle and toxicology in global coastal aquifers.

Distinct variations in fluorescent DOM components along a trophic gradient in the lower Fox River-Green Bay as characterized using one-sample PARAFAC approach

Variations in molecular weight distributions of dissolved organic matter (DOM) and PARAFAC-derived fluorescent components were investigated along a transect in the seasonally hypereutrophic lower Fox River-Green Bay using the one-sample PARAFAC approach coupling flow field-flow fractionation for size-separation with fluorescence excitation-emission matrix (EEM) and PARAFAC analysis. Concentrations of dissolved organic carbon and nitrogen, chromophoric-DOM, specific UV absorbance at 254 nm, and humification index all decreased monotonically from river to open bay, showing a strong river-dominated DOM source and a dynamic change in DOM quality along the river-lake transect. The relative abundance of colloidal DOM (>1 kDa) derived from ultrafiltration exhibited minimal variation, averaging 71 ± 4 % of the bulk DOM, across the entire estuarine transect although the colloidal concentration decreased in general. Using the one-sample EEM-PARAFAC approach, the identified major fluorescent components were distinct between stations along the river-estuary-open bay continuum, with four components in river/upper-estuary but three components in open bay waters. Among the four common fluorescent components (C475, C410, C320 and C290), the most abundant and refractory humic-like component, C475, behaved conservatively and its relative abundance (%ΣFmax) remained fairly constant (50 ± 4 %) along the transect, while the semi-labile humic-like component, C410, consistently decreased from river to estuary and eventually vanished in open Green Bay. In contrast, the two autochthonous protein-like components (C320 and C290) increased from river to open bay along the trophic gradient. The new results presented here provide an improved understanding of the diverse and fluctuating characteristics in DOM composition, lability, and estuarine mixing behavior across the river-lake interface and demonstrate the efficacy of the one-sample PARAFAC approach.