Particle Settling Research Articles

Understanding the aggregation, consumption, distribution and accumulation of nanoparticles of polyvinyl chloride and polymethyl methacrylate in Ruditapes philippinarum

Plastic products have become an integral part of our life. A widespread usage, high stability, uncontrolled disposal and slow degradation of plastics in the environment led to the generation and accumulation of nanoparticles of polymers (NPs) in the marine environment. However, little is known about the aggregation, consumption and distribution of NPs from common polymers such as polyvinyl chloride (NP-PVC) and polymethyl methacrylate (NP-PMMA) inside marine animal physiologies. In the current study, two types of polymers (PVC and PMMA) × four exposure concentrations (1, 5, 15 and 25 mg/L) × four times (4, 8, 12 and 24 h) exposure studies were conducted to understand the consumption and distribution of luminescent NP-PVC (98.6 ± 17.6 nm) and NP-PMMA (111.9 ± 37.1 nm) in R. philippinarum. Under laboratory conditions, NP-PVC showed a higher aggregation rate than NP-PMMA in seawater within a period of 24 h. Aggregations of NPs increased with an increase in initial NP concentrations, leading to significant settling of nanoparticles within 24 h exposure. Such aggregation and settling of particles enhanced the consumption of NPs by benthic filter-feeding R. philippinarum at all exposure concentrations during 4 h exposure. More interestingly, NP-PVC and NP-PMMA were observed in large amounts in both liver and gills (22.6 % - 29.1 %) of the clams. Furthermore, NP-PVC was detected in most organs of R. philippinarum as compared to NP-PMMA. This study demonstrates that different polymers distribute and accumulate differently in the same biological model under laboratory exposure conditions based on their chemical nature.

Diblock Copolymer Stabilized Liquid Metal Nanoparticles: Particle Settling Behavior and Application to 3D Printing.

Eutectic gallium indium (EGaIn) is a liquid metal with promising applications due to its favorable thermal and electrical conductivity, low viscosity, and metallic nature. For applications, including imaging, catalysis, and nanomedicine, stable EGaIn particles with submicron diameters are required. However, the low viscosity and high density of EGaIn have typically precluded the formation of stable submicron particles due to rapid EGaIn droplet coalescence. In this work, we show that poly(acrylic acid)-block-poly(N,N'-dimethylacrylamide) copolymers are able to effectively stabilize EGaIn nanodroplets formed upon ultrasonication, where the poly(acrylic acid) block anchors the polymer to the EGaIn surface and the poly(N,N'-dimethylacrylamide) block provides colloidal stability to the particles in solution. Although the high density of EGaIn causes rapid particle settling, the behavior is predictable, which allows the average particle size to be controlled through centrifugation. We demonstrate that stable EGaIn particles with sizes on the order of 50-100 nm and narrow particle size distributions can be easily obtained using this method and further used in photopolymer resins to prepare 3D printed EGaIn-polymer hybrid materials. The predictable sizes and high stability of these EGaIn nanoparticles should allow further applications in soft-electronics, nanomedicine, catalysis, and other nanotechnology.

Why do ventilation strategies matter in controlling infectious airborne particles? A comprehensive numerical analysis in isolation ward

A proper ventilation strategy in an isolation ward could promote better indoor air quality for the occupants. This could also reduce the risk of immunocompromised patients contracting healthcare-associated infections (HAI) or airborne diseases such as COVID-19, tuberculosis, and measles among others. This study aims to propose and examine appropriate ventilation strategies in a single-patient isolation ward that can reduce particle settlement in patients. A simplified CFD model of the isolation ward was developed and well-validated against established data. An RNG k-ε model and discrete phase model (DPM) were used to simulate airflow and particle transportation. The study examined the airflow and particle dispersion under a baseline case and four proposed ventilation strategies. Results showed that the baseline case study, which used the ceiling-mounted air curtain was insufficient to prevent the particles from dispersing into the vicinity of the patient. Likewise, the dilution effect under the baseline case and case 4 (wall-mounted air supply diffuser) were relatively weak due to the low air change rate (ACH) of 4/hr and 9/hr respectively. The ventilation strategy in case 4 has a negligible effect on reducing the particles (14%) settling on the patient although the ACH in case 4 was 2-times the baseline case. The present finding ascertains that utilising the combination of ceiling-mounted air diffuser and air curtain jet (case 3) results in zero particle settlement on both patient's and the patient's bed. It also reduced 57% of particles in the vicinity of the medical staff's breathing zone compared to the baseline case.

Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean

Abstract. Supply of iron (Fe) to the surface ocean supports primary productivity, and while hydrothermal input of Fe to the deep ocean is known to be extensive it remains poorly constrained. Global estimates of hydrothermal Fe supply rely on using dissolved Fe (dFe) to excess He (xs3He) ratios to upscale fluxes, but observational constraints on dFe/xs3He may be sensitive to assumptions linked to sampling and interpolation. We examined the variability in dFe/xs3He using two methods of estimation, for four vent sites with different geochemistry along the Mid-Atlantic Ridge. At both Rainbow and TAG, the plume was sampled repeatedly and the range of dFe/xs3He was 4 to 63 and 4 to 87 nmol:fmol, respectively, primarily due to differences in plume age. To account for background xs3He and shifting plume position, we calibrated He values using contemporaneous dissolved Mn (dMn). Applying this approach more widely, we found dFe/xs3He ratios of 12, 4–8, 4–44, and 4–86 nmol fmol−1 for the Menez Gwen, Lucky Strike, Rainbow, and TAG hydrothermal vent sites, respectively. Differences in plume dFe/xs3He across sites were not simply related to the vent endmember Fe and He fluxes. Within 40 km of the vents, the dFe/xs3He ratios decreased to 3–38 nmol fmol−1, due to the precipitation and subsequent settling of particulates. The ratio of colloidal Fe to dFe was consistently higher (0.67–0.97) than the deep N. Atlantic (0.5) throughout both the TAG and Rainbow plumes, indicative of Fe exchange between dissolved and particulate phases. Our comparison of TAG and Rainbow shows there is a limit to the amount of hydrothermal Fe released from vents that can form colloids in the rising plume. Higher particle loading will enhance the longevity of the Rainbow hydrothermal plume within the deep ocean assuming particles undergo continual dissolution/disaggregation. Future studies examining the length of plume pathways required to escape the ridge valley will be important in determining Fe supply from slow spreading mid-ocean ridges to the deep ocean, along with the frequency of ultramafic sites such as Rainbow. Resolving the ridge valley bathymetry and accounting for variability in vent sources in global biogeochemical models will be key to further constraining the hydrothermal Fe flux.

Experimental measurement of enhanced and hindered particle settling in turbulent gas-particle suspensions, and geophysical implications

Experimental measurement of enhanced and hindered particle settling in turbulent gas-particle suspensions, and geophysical implications

Does human movement-induced airflow elevate infection risk in burn patient’s isolation ward? A validated dynamics numerical simulation approach

An isolation ward requires a highly controlled and contamination-free environment since the settling of bacteria-carrying particles (shed by medical staff) on patients’ wounds could cause infections. The present study examines the effect of medical staff’s walking movement on airflow distribution and particle dispersion. Three different walking speeds of 0.25 m/s, 0.5 m/s, and 1.0 m/s were assigned to the medical staff. An RNG k-ɛ model based on the Reynolds-Averaged Navier-Stokes (RANS) equation was adopted to predict the airflow, while a Lagrangian tracking approach was selected to track particle dispersion. The reliability of the selected airflow turbulent model and particle tracking approach was validated using published data. The present study showed that the low-pressure region behind the moving medical staff’s body has induced wake. The higher walking speed of 1.00 m/s produced a significant secondary airflow of 1.12 m/s, while 0.25 m/s and 0.5 m/s generated lower secondary airflow of 0.41 m/s and 0.53 m/s, respectively. The number of particles settled on the patient at 0.25 m/s, 0.50 m/s, and 1.00 m/s were 31, 18 and 5, respectively. Present finding indicated that a higher walking speed reduces the number of particles settled on the burn patient, therefore potentially reducing the associated nosocomial infection risk.

Analysis of the Impact of Vermiculite on Hematite-Based Cement Systems.

Heavyweight oil-well cement systems are designed for isolating intervals and supporting the casing at deeper depths where high temperatures and pressures are encountered. The cement slurry should have adequate rheology to ensure efficient placement. Additionally, the hardened cement sheath should be homogeneous with lower porosity and permeability, higher strength, and sufficient flexibility. The effect of vermiculite on hematite-based cement samples has been investigated. The methodology and testing were based on the American Petroleum Institute standards and other recognized recommendations. Fluid properties were characterized by their rheology, while petrophysical and mechanical properties were used to analyze the properties of hardened cement specimens. The vermiculite was used in concentrations of 0.25, 0.5, 1, and 2% by weight of cement (BWOC). The slurries were cured at 3000 psi and 292 °F in cubic and cylindrical molds for 24 h. The results indicate that using 1% BWOC of vermiculite yields the best cement properties. It minimizes the settling of hematite particles to a very low value compared to the base cement as shown by the method of density variation and confirmed by nuclear magnetic resonance. Compared to the base cement slurry, the slurry of 1% BWOC of vermiculite has desirable rheology in terms of plastic viscosity and gel strength. The incorporation of 1% BWOC improves the strength of the cement sheath by 50.7% for the compressive strength and 65% for the tensile strength. Adding 1% vermiculite reduces the permeability and porosity of the cement by 45.8 and 43.5% compared to the control cement. In addition, the 0.7% vermiculite cement is more flexible than the control cement in terms of the elastic properties represented by lower Young's modulus (a reduction of 33%) and higher Poisson's ratio (an increase of 2%).

Particle orientation distribution in a rotating, dilute suspension of rod-shaped particles

We consider a theoretical model for the settling of rod-shaped particles of a dilute, initially homogeneous, suspension in rapid rotation. The particle Reynolds number and the particle Taylor number of the detailed flow around the particles are assumed small, representing a relevant limit for an industrial centrifugal separation process. By applying a statistical approach using the Fokker–Planck equation, and neglecting particle–particle interactions, we obtain an explicit, analytical solution for the time dependent, spatially uniform particle orientation distribution function. Not only does the volume fraction in the bulk of the suspension decrease with time due to the divergent centrifugal field, as similarly described in the literature for suspensions of spherical particles, the orientation of the rod particles also changes with time from an initially uniform distribution to one where the particles tend to align with a plane perpendicular to the axis of rotation. The corresponding particle trajectories, as also influenced by first-order effects from the Coriolis acceleration and gyroscopic effects, are obtained numerically for different initial particle orientation angles.

Quantification of gas, ash, and sulphate aerosols in volcanic plumes from open path Fourier transform infrared (OP-FTIR) emission measurements at Stromboli volcano, Italy

Field-portable Open Path Fourier Transform Infrared (OP-FTIR) spectrometers can be used to remotely measure the composition of volcanic plumes using absorption spectroscopy, providing invaluable data on total gas emissions. Quantifying the temporal evolution of gas compositions during an eruption helps develop models of volcanic processes and aids in eruption forecasting. Absorption measurements require a viewing geometry which aligns infrared source, plume, and instrument, which can be challenging. Here, we present a fast retrieval algorithm to estimate quantities of gas, ash and sulphate aerosols from thermal emission OP-FTIR measurements, and the results from two pilot campaigns on Stromboli volcano in Italy in 2019 and 2021. We validate the method by comparing time series of SO2 slant column densities retrieved using our method with those obtained from a conventional UV spectrometer, demonstrating that the two methods generally agree to within a factor of 2. The algorithm correctly identifies ash-rich plumes and gas bursts associated with explosions and quantifies the mass column densities and particle sizes of ash and sulphate aerosols (SA) in the plume. We compare the ash sizes retrieved using our method with the particle size distribution (PSD) of an ash sample collected during the period of measurements in 2019 by flying a Remotely Piloted Aircraft System into the path of a drifting ash plume and find that both modes of the bimodal PSD (a fine fraction with diameter around 5–10 μm and a coarse fraction around 65 μm) are identified within our datasets at different times. We measure a decrease in the retrieved ash particle size with distance downwind, consistent with settling of larger particles, which we also observed visually. We measure a decrease in the SO2/SA ratio as the plume travels downwind, coupled with an increase in measured SA particle size (range 2–6 μm), suggesting rapid hygroscopic particle growth and/or SO2 oxidation. We propose that infrared emission spectroscopy can be used to examine physical and chemical changes during plume transport and opens the possibility of remote night-time monitoring of volcanic plume emissions. These ground-based analyses may also aid the refinement of satellite-based aerosol retrievals.

INFILTRATION AND COLMATATION DYNAMICS ON PHYSICAL MODELS STUDY BY INFILTRATION BASINS AT ARTIFICIAL GROUNDWATER RECHARGE

The problem of the growing shortage of water resources in the world, including in the territory of South-East Kazakhstan, due to global warming and aggravated by long distances to natural sources of good quality water, requires the combined use of surface water and groundwater from local aquifers to supply the local population with high-quality drinking water. The application of methods of artificial groundwater spreading can be an effective way only if positive characteristics of soil and soil parameters of the aeration zone and productive aquifers are obtained in the processes of infiltration and colmatation, which are one of the decisive indicators for ensuring productivity and duration of operation of infiltration basins in the given mode. This work presents the main results of complex field studies of the processes of infiltration and colmatation in infiltration mini-basins at pilot sites within the Aksu, Lepsy and Koksu river valleys, taken as typical for the territory of South-Eastern Kazakhstan, which most needs to increase the water supply of rural population settlements and remote pastures. These studies were supplemented by a detailed assessment of the water-physical, hydrodynamic and filtration properties of the overburden and the upper layers of the aquifer. The new data showed that the infiltration rate varied from 15 m/day at the beginning to 0.75 m/day at the end and remained practically unchanged by the end of the experiment. This was largely facilitated by the values of the heterogeneity coefficient of the granulometric composition of all the examined soils obtained during the studies, which did not exceed 3.0 due to the uniform distribution of coarse fractions and a small proportion of loams and sandy loams. Approximately one month after the start of the tests, a colmatation layer began to be generated at the bottom of the mini-ponds, the thickness of which by the end of the test reached from 3 mm for clay silt to 6 mm for silty clay. However, as studies have shown, the generation of a colmatation layer due to the settling of suspended particles of surface water did not significantly impact on the infiltration processes, as evidenced by the rated values of specific flow rates, which in the final period of time ranged from 0.86 to 0.75-0.80 m3/day per square meter of reduced infiltration surface. Thus, the generated positive results of field studies can serve as a factual basis for design, and can also be recommended and accepted as design indicators both at the stage of a feasibility study and at the stage of detailed design of artificial groundwater spreading systems without additional labor-intensive and costly survey works, and the approved methodology for their implementation will be useful when conducting similar studies in other regions.

Settling velocity variation induced by a sphere moving across a two-layer stratified fluid with different rheological characteristics.

Particle settling in stratified fluids is widespread in chemical and pharmaceutical processes, and how to effectively regulate the particle velocity is the key to optimizing the above process technology. In this study, the settling of individual particle in two stratified fluids, water-oil and water-PAAm was studied using the high-speed shadow imaging method. In the Newtonian stratified fluid of water-oil, the particle penetrates the liquid-liquid interface and forms unsteady entrained drops of different shapes, and the settling velocity becomes smaller. In contrast, in water-PAAm stratified fluids, the shear-thinning and viscoelasticity of the lower fluid will cause the entrained drops of the particle to appear a stable sharp cone shape, and the particle can thus obtain a smaller drag coefficient ( < 1) and a significantly enhanced settling velocity (U* > 1) compared to the uncovered PAAm solution (PAAm solution without overlayer oil). This study can provide a new path for the development of new particle velocity regulation techniques.

Continuous floc image analyser (C-FIA) for tracking floc particle dynamics during coagulation–flocculation–settling processes

A continuous floc image analyser (C-FIA) was developed for tracking the dynamics of floc particle formation, growth and settling during conventional water treatment. This is based on a new RGB signal for flocculation index determination.

Сравнительная оценка распределения Cs-137 в почвенном покрове на территории Таджикистана

The article presents the results of a comparative assessment of the distribution of the technogenic radionuclide Cs-137 in the soil cover on the territory of the Republic of Tajikistan. It is noted that the accumulation of the 137Cs isotope in the territory depends on the terrain and soil type. At the foot of the mountains and in clay soils, a relatively high content of the Cs-137 isotope is observed compared to plains and sandy soils. The migration of radionuclide Cs-137 deep into the vertical is observed in the soils of sandy rock. It is shown that the values of the average specific activity of the Cs-137 isotope in the soil cover of Southern Tajikistan are 2.5 times lower than the average specific activities of the soils of Northern and Central Tajikistan. The highest values of specific soil activity of 17.0 Bq/kg were noted in the southeastern regions of Tajikistan. This circumstance is primarily due to the fact that precipitation and dust storms coming from the countries of South and Southeast Asia lead to the settling of particles, primarily on the slopes of the mountains. Thus, based on the analysis of the literature review in the direction under study and the results obtained, the authors revealed that the spatial distribution of Cs-137 radionuclide in the soil cover in the Republic of Tajikistan depends on the direction of the wind rose and the terrain. Analysis of the samples obtained allows us to conclude that the content of Cs-137 radionuclide is due to its long-range air transport.

Determination of the trajectory of sedition of fluid particles in the forebay of pumping stations

In the article, the determination of the sedimentation territory of turbid particles in the forebay of the irrigation pumping station is aimed at preserving the useful volume of the forebay, in which the forebay of the irrigation pumping station PK-1512+01 GFC (The great Fergana canal) and SEC (Sokh Eastern Canal) located in the large Fergana canal is taken as an object. The review of the literature showed that the deposition of particles is directly related to the following factors, which are affected by the speed of the flow, the diameter of the particle, the difference between the densities of water and the particle, the shape of the particle and the order of movement of the flow, the viscosity of water and other factors. In these studies, we primarily aim to increase the performance of the forebay by defining the particle settling zone to preserve the useful vane size. Calculations of the method of calculating the sedimentation rate of cloudy particles using theoretical and empirical formulas were carried out and conclusions were drawn by comparing the results.

High-resolution model of complexly shaped bodies motion using an IBM-VOF-DEM coupling method

A new coupling model that focuses on the simulation of gas-liquid flow and irregular-shaped particulate flows was proposed based on the coupling of FD/IBM, VOF and DEM. A wide range of computing cases was presented for validation, including the spherical and cylindrical particle settling in fluid, where the particle Reynold's number is small, and the vortex shedding phenomenon could still be captured. Further, the simulations that the wooden blocks float upward and the cones fall into the water at a high Reynolds number were constructed. All these simulating results keep well consistent with the experiments. It turns out that the model is reliable for simulating the particulate flows as Reynold's number is up to 420,000. Besides, the model shows great strength of the solid-fluid motions capture capability, especially for the irregular-shaped objects moving trajectories at different scales from 0.00167 to 0.3 m, which is potentially helpful in industrial engineering. • A fully rsolved IB-VOF-DEM model is developed. • Typical and multi-scaling validating simulations are presented. • The model covers a wide range of Reynolds number from 400 to 420,000. • Multi-sphere model and Monte-Carlo method are employed.

Bridging the gap between solids suspension theory and equipment design

The aim of this research was to investigate the effect of equipment design on suspending solid particles in stirred vessels. We investigated and evaluated several improvements to the Grenville-Mak-Brown correlation for the just-suspended impeller speed with the goal of generalizing it. We present two new geometry-specific as well as generalized suspension correlations based on experiments made with 225 µm sand in water in four vessel geometries: cylindrical flat-based, cylindrical torispherical dish-based, square flat-based, and horizontally oriented cylindrical vessels. We also present novel experimental data for both a wide blade hydrofoil and a pitched blade turbine. We define a vessel sphericity parameter to generalize the various tanks into a single correlation permitting interpolation to other vessel types and sizes not tested. We further show how controlled particle settling can be used to transform a flat-based stirred vessel into an equivalent torispherical dish-based vessel to save energy.

Particle-associated bacteria in seawater dominate the colony-forming microbiome on ZoBell marine agar.

Planktonic particle-associated bacteria comprise particle-attached and motile free-living cells. These groups were obtained by settlement in Imhoff cones. Dilution plating on marine agar 2216 (ZoBell marine agar) and microscopic counts indicated a cultivability of 0.7% (0.4%-1.2%) of bacteria in coastal seawater collected at Helgoland Roads, North Sea. Particle-associated bacteria presented a minority population in seawater, but had a larger cultivability of 25% (0.9%-100%) for populations collected by settlement of particles and 5.7% (0.9%-24%) for populations collected by filtration. Partial 16S rRNA gene sequences indicated that 84% of the cultured taxa were either enriched in particle-associated microbiomes or only found in these microbiomes, including Sulfitobacter and other Rhodobacteraceae, Pseudoalteromonas, Psychromonas, Arcobacter and many Flavobacteriaceae. Illumina-based 16S rRNA V3V4 amplicon sequences of plate communities revealed that nearly all operational taxonomic units had a cultivated and described strain in close phylogenetic proximity. This suggested that decades of strain isolation from seawater on ZoBell marine agar had achieved a very good coverage of cultivable genera abundant in nature. The majority belonged to particle-associated bacteria, complementing observations that abundant free-living seawater bacteria often require cultivation conditions closer to their natural habitat like liquid cultivation in oligotrophic medium.

Modeling of dynamic bridging of solid particles in multiple propagating fractures

During multi-cluster fracturing, solid particles are widely used to alleviate the non-uniform fluid distribution and fracture growth. Even though diversion technology has been applied and proved effective in numerous field applications, many involved physical mechanisms, such as solid diverters transport, settling, bridging, and packing in multiple propagating fractures, remain unclear. In this work, a computational mechanics system is developed to interpret the coupling process of fluid flow, fracture propagation, and particle transport. The moving fracture front is located using the implicit level set algorithm (ILSA) and tip asymptotic solution. The diverter particle transport model can capture the settling, bridging, and packing of particles; thus the slurry flow in the fracture can transit from Poiseuille flow to Darcy flow naturally. Application of the developed system to simulate a single stage of three equally spaced clusters indicates that it is possible to create multiple fractures with uniform length using diversion technology, but their widths are non-uniform. Instead, they demonstrate pinched or ballooned shapes, because of the stress interference. An extensive parametric study is also performed to investigate how various parameters affect diversion efficiency.

Numerical simulation of social distancing of preventing airborne transmission in open space with lateral wind direction, taking into account temperature of human body and floor surface.

This paper presents the numerical results of particle propagation in open space, taking into account the temperature of the human body and the surface of the ground. And also, the settling of particles or droplets under the action of gravitational force and transport in the open air is taken into account, taking into account the temperature during the process of breathing and sneezing or coughing. The temperature of the body and the surface of the ground, different rates of particle emission from the mouth, such as breathing and coughing or sneezing, are numerically investigated. The effect of temperature, cross-inlet wind, and the velocity of particle ejection from a person's mouth on social distancing is being investigated using a numerical calculation. The variable temperature of the human body forms a thermal plume, which affects the increase in the trajectory of the particle propagation, taking into account the lateral air flow. The thermal plume affects the particles in the breathing zone and spreads the particles over long distances in the direction of the airflow. The result of this work shows that in open space, taking into account the temperature of the body and the surface of the ground, a 2-m social distance may be insufficient for the process of sneezing and social distance must be observed depending on the breathing mode.

Effect of channel width on the sedimentation modes of a cold elliptical particle in hot narrow channels

Many natural and industrial processes involve transport of solid particles. This research reports sedimentation modes of a single cold elliptical particle with an aspect ratio of 2 in narrow hot channels. Prior research on settling of non-isothermal elliptical particles was limited to wide vertical channels. A cold particle with constant non-dimensional temperature of T p ∗ = 0 and an initial orientation of θ 0 = π / 3 between its major axis and horizontal axis is released in a hot fluid. Fluid Prandtl number is 7, and its initial temperature is T f , 0 ∗ = 1 . Simulations are based on an in-house lattice-Boltzmann solver with two distribution functions for fluid flow and heat transfer and using Boussinesq approximation in low density variations. In total, 120 simulations in five channel widths have been run, with enough time for the particle to reach a distinct sedimentation/rising pattern. Effects of channel width ( L = 12 A / 13 − 38 A / 13 ), where A is ellipse major diameter, the Grashof number ( Gr = 100 − 1000 ), and particle-to-fluid density ratio ( ρ r = 1 . 0003 − 1 . 3 ) have been studied. Channel width, gravity and heat transfer have been discovered to cause the particle to travel up or down. Seven sedimentation modes have been observed including i) horizontal at centerline, ii) inclined off-center, iii) vertical at center, iv) oscillatory motion around centerline, v) tumbling off-center, vi) horizontal fluttering at centerline, and vii) inclined off-center with oscillations. Three of these patterns (iii, iv, vii) are peculiar to narrow channels, and have not previously been observed for cold elliptic particles in wide channels ( L = 52 A / 13 ). Moreover, the particle has been seen to move upward rather downward in the narrowest channel for small particle-to-fluid density ratios. • Sedimentation modes of a cold elliptical particle in hot narrow channels are studied. • In total seven settling modes are observed; three of them are new and unique to narrow channels. • Grashof and Archimedes number and channel width have significant influence on the sedimentation pattern. • In narrow channels, wall and heat transfer effect are stronger than in wide channels and can even push the particle upward by overcoming the gravity. • Sedimentation velocity of the particle has been seen to be lower in narrow channels compared to wider ones.