Deposition Patterns Research Articles

Facile Synthesis of Rhodium-Based Nanocrystals in a Metastable Phase and Evaluation of Their Thermal and Catalytic Properties.

Controlling the polymorphism of metal nanocrystals is a promising strategy for enhancing properties and discovering new phenomena. However, previous studies on Rh nanocrystals have focused on their thermodynamically stable face-centered-cubic (fcc) phase. Herein, a facile synthesis of Rh-based nanocrystals featuring the metastable hexagonal close-packed (hcp) phase is reported by using Ru seeds in their native hcp phase to template the deposition of Rh atoms. The success of such phase-controlled synthesis relies on the templating effect promoted by the small lattice mismatch between Ru and Rh and the slow dropwise titration of the precursor at an elevated temperature, ensuring the layer-by-layer growth mode and thus the formation of a conformal hcp-Rh shell. Faster injection rate of Rh(III) precursor leads to the formation of a rough Rh shell in the conventional fcc phase due to accelerated reaction kinetics. Considering both thermodynamic and kinetic aspects of this system, the hcp-Rh phase is favored when the low surface energy from smooth overlayers balances the high bulk energy of the metastable phase, achieved through tight control of reaction rates and deposition patterns. These Ruhcp@Rhhcp core-shell nanocrystals demonstrate thermal stability up to 400°C, while exhibiting higher catalytic activity toward ethanol oxidation reaction compared to Ruhcp@Rhfcc counterparts.

Association between sebum secretion and cardiac sympathetic dysfunction in Parkinson's disease

BackgroundPatients with Parkinson's disease (PD) have α-synuclein (α-Syn) deposition in the skin, and decreased sebum secretion due to epidermal dysfunction. However, the relationship between sebum secretion and autonomic neuropathies is unknown. MethodsUsing the medical records in our facility, we identified patients newly diagnosed with PD on admission from August 2020 to December 2023. We analyzed whether sebum secretory ability at multiple sites was associated with cardiac sympathetic nerve function that was assessed by cardiac 123I-metaiodobenzylguanidine scintigraphy. ResultsForty patients were included. Their sebum secretion ability positively correlated with the ratio of the average pixel count in the heart to that in the mediastinum (H/M ratio) in the posterior neck, the anterior chest, the arms, and the abdomen. In the multiple regression analysis, those in the arms (β, 8.8; 95 % CI, 4.4–13.2; P < 0.001) and abdomen (β, 1.3; 95 % CI, 0.1–2.5; P = 0.032) were associated with the H/M ratio after controlling for age, sex, and UPDRS part III. ConclusionThis study revealed an association between sebum secretion in the arms and the abdomen, and cardiac sympathetic nerve function in PD patients. The site of the sebum secretory disturbance associated with cardiac sympathetic nerves closely resembled the gradient of α-Syn deposition in the skin, corroborating its deposition pattern. Our findings suggest that noninvasive sebum measurement may serve as an adjunctive diagnostic tool of α-Syn deposition in the skin for PD and provide insights into sympathetic nerve damage alongside cardiac sympathetic nerve assessments.

Holocene aeolian-fluvial interactions patterns and their response to climate changes in the Paiku Co basin, Southern Tibetan Plateau

Aeolian-fluvial processes are crucial in shaping landforms. Despite the advancements in understanding the sedimentary processes of aeolian-fluvial interactions, the sedimentary patterns of these interactions are complex in spatiotemporal scale, and the records of Holocene small-scale aeolian-fluvial interaction sedimentary is insufficient, especially in the Tibetan Plateau region. Therefore, this study focuses on analyzing the sedimentary patterns of aeolian-fluvial interactions and their response to climate change in the Paiku Co basin of the southern Tibetan Plateau (TP). Through the examination of aeolian-fluvial sequences, Optically Stimulated Luminescence (OSL) dating is utilized to establish a chronological framework. Furthermore, proxy indices are explored to identify potential sediment models and their reactions to climate change. The findings indicate that fluvial activity predominated during a relatively warm and wet period around 5.1–4.6 ka, while thicker aeolian sands accumulated extensively during 4.6–4.1 ka as the climate transitioned to cold and dry conditions. On a millennial scale, the aeolian-fluvial interaction sedimentation is characterized by alternating deposition of clay layers and medium to fine sand. This sedimentation pattern is predominantly influenced by climate change. Overall, the findings shed light on the complex coupling between aeolian and fluvial processes in response to past climate changes, which has important implications for understanding the landscape evolution and environmental changes in this sensitive high-altitude region.

Ichnoguild analysis of the Bajocian-Bathonian Yellow Flagstone Member (Goradongar Formation) from the Kachchh Basin, Western India

The Yellow Flagstone is the oldest member of the Goradongar Formation exposed in the Pachchham Island, Kachchh Basin. The members exposed in four sections are mapped for trace fossils, and 17 ichnofossils have been documented. The concept of ichnoguild (IG) is applied to reveal the infaunal tiering structure and the strategies organisms adapt to exploit the resources. Ten IG of similar characteristics and ecological functions have been identified. Five are shallow-tier IGs ( Asterosoma IG, Gyrochorte IG, Nereites IG, Planolites IG and Bolonia IG), three middle-tier IGs ( Rhizocorallium IG, Arenicolites-Diplocraterion IG and Zoophycos-Teichichnus IG) and two deep-tier IGs ( Skolithos Arenicolites IG and Thalassinoides-Ophiomorpha IG). The analysis of three ichnological tiers and their IGs, namely shallow, middle and deep-tiers across the stratigraphy of Yellow Flagstone Member suggests a transition from a lower shoreface environment to offshore transition environments. The transition is supported by an increase in deep-tier IG and the marginal increase in the ichnodiversity and density. Changes in the composition and abundance of IGs over time can indicate shifts in sedimentation patterns, sea level fluctuations and paleoenvironmental conditions within the basin. Thus, the findings suggest an environmental shift from shoreface to offshore transition indicative of a transgression during the deposition of upper Bajocian to lower Bathonian Yellow Flagstone Member in the Kachchh Basin. The study also examines the temporal and spatial changes in the IGs, contributing to a better understanding of ecological changes within the basin. The findings contribute to the broader knowledge of paleoecology and provide valuable data for sedimentological and stratigraphic interpretations in sedimentary basins.

Mass concentrations, compositions and burial fluxes of nano- and micro-plastics in a multi-species saltmarsh

Plastic pollution poses a serious threat to marine ecosystems; yet quantifying the mass concentrations of nano- and microplastics (NMPs) in saltmarsh sediments at the ocean-land interface remains a critical research gap. Here, the study employed reliable and efficient analytical techniques, namely pressurized liquid extraction and the double-shot model of thermal desorption/pyrolysis-gas chromatography-mass spectrometry, to quantify six different types of NMPs in the sediment of a multi-species saltmarsh, providing the first comprehensive assessment of NMP mass concentration and burial in this saltmarsh environment. The results demonstrate that polyethylene, polyvinyl chloride, and polypropylene dominated the NMP composition in sediments, constituting 72.6%, 17.3%, and 4.5% of the total NMPs, respectively. The measured NMPs represent an anthropogenic intrusion, constituting 0.10%–0.23% of the carbon storage in the saltmarsh. By examining the vertical concentration profiles, this study unveiled the influence of saltmarsh vegetation on NMP deposition in sediments, establishing a connection with local sedimentation patterns and the historical zonation of plant species such as Scirpus mariqueter, Phragmites australis and Spartina alterniflora. These findings underscore the crucial role of saltmarsh vegetation in facilitating NMP settling and retention, highlighting the necessity of considering vegetation dynamics in examining the emerging NMP pollution in coastal wetlands.

Atmospheric Microplastics Emission Source Potentials and Deposition Patterns in Semi‐Arid Croplands of Northern China

AbstractFrequent wind erosion events in semi‐arid regions can lead to significant atmospheric microplastic (MP) emissions from croplands. We examine observed and predicted characteristics of atmospheric MPs over cropland in Northern China. Measurements showed that fibers were the predominant morphology, accounting for 69% of the 198 observed MPs. The observed atmospheric MP abundance varied widely, averaging 0.088 # m−3 in the absence of air masses passing through near‐surface croplands and increasing significantly to 0.26 # m−3 when such air masses were present. The predictions of deposition flux for atmospheric MPs over croplands indicated a spatial variation ranging from less than 0.5 g km−2 day−1 in the north to over 15 g km−2 day−1 in the south, corresponding to an average of approximately 13.3 g km−2 day−1. Our findings highlight the dual role of surface soil as both a potential source and sink of atmospheric MPs, underscoring the need for further research on the regional dynamics of wind‐driven MP emissions and their associated ecosystem health risks in semi‐arid croplands.

In Vitro Analysis of Aerodynamic Properties and Co-Deposition of a Fixed-Dose Combination of Fluticasone Furoate, Umeclidinium Bromide, and Vilanterol Trifenatate.

Effective airway delivery of a fixed-dose combination of triple-aerosolized inhaled corticosteroid (ICS)/long-acting beta agonist (LABA)/long-acting muscarinic antagonist (LAMA) is likely to positively affect therapeutic responses predicted in patients with asthma and chronic obstructive pulmonary disease. This study aimed to conduct in vitro fluticasone furoate, vilanterol trifenatate, and umeclidinium bromide depositions in a Next Generation Impactor. The aerodynamic properties of these inhaled medications influence the spatial distribution and drug abundance, particularly in the smaller airways, to reverse or alleviate disease pathology. The Next Generation Impactor was used to demonstrate the aerodynamic particle size distributions of fluticasone furoate, vilanterol trifenatate, and umeclidinium bromide delivered from a dry powder inhaler at different flow rates across all stages of the impactors. This in vitro study analyzed the distribution pattern of individual drug components to simulate mono-component deposition and co-deposition in the official model in the United States Pharmacopeia. An Andersen cascade impactor together with scanning electron microscope-energy-dispersive X-ray was employed to observe the drug deposition on each stage of the impactor. We found that the distribution pattern of each component at the same cascade level was comparable, and the aerosol particles of the three drugs reached the in vitro representation of the lower airway compartment. The specified flow rates generated the desired fine particle fraction, fine particle dose, and mass median aerodynamic diameter. Our results also demonstrated visualized deposition patterns of the delivered drugs from different stages of the cascade impactor that may predict deposition as it occurs in vivo. Spatial distribution and abundance of ICS/LABA/LAMA in the same cascade levels were closely comparable, and the aerosol particles were able to reach the small aerosol-sized cascades at the lower levels to some extent.

A New Pattern of Phytomelanin Deposition in Cypselae of Bahieae (Asteraceae, Heliantheae Alliance)

ABSTRACTPhytomelanin is the dark and highly inert substance found in the fruit walls of the Heliantheae alliance clade within Asteroideae (Asteraceae). Phytomelanin deposition pattern in the cypselar wall was studied in two taxa of the Bahieae—Bahia pedata A. Gray and Palafoxia arida B. L. Turner. The pericarp anatomy studies have revealed that the phytomelanin deposits in the schizogenous space between the hypodermis and fiber layer. Our findings reveal that phytomelanin deposition is associated with fiber and has also brought out a new pattern of phytomelanin deposition between inner (fibrous zone) and outer sclerified layers (hypodermal) in the schizogenous space. The study recorded a first‐time report of a second layer of phytomelanin outer to the sclerified hypodermal cells at maturity. Our observations point to phytomelanin precursors being synthesized as pliable fluid substances associated with fiber cells and solidifies later in the intercellular space. The study also recorded the first report for the occurrence of tracheoidal cells in the pericarp wall of the Bahieae within the Heliantheae alliance. Our study has provided insights to decipher evolutionary patterns and the significance of phytomelanin in the phytomelanic fruit clade (PFC), and it could help to resolve long‐standing debates on deposition patterns and the site of synthesis of phytomelanin.

Distribution and Controlling Factors of the Contourites on the Northern Continental Slope of the South China Sea

ABSTRACTThe northern continental margin of the South China Sea (SCS) is an important component of deep‐water circulation, providing excellent conditions for studying bottom currents in a marginal sea. Seismic data were employed to discern the sedimentary patterns prevalent in the deep‐water continental slope sediments on the northern continental margin of the SCS, encompassing gravity flow, contourite and mixed depositional systems. The contourite depositional system includes various types of deposits (such as separated mounded drifts, patch or channel‐related drifts, deformed sheeted drifts, composite drifts, bottom current sediment waves, plastered contourite drifts) and various morphologic erosional features eroded by the bottom current (such as moats, non‐depositional surfaces, troughs and scarps). These contourite features are related to the continental slope's morphology and its sources. The Dongsha slope exhibits distinctive characteristics marked by intense bottom current erosion and deposition, featuring separated mounded drifts and deformed sheeted drifts along its lower slope. The lower slope of the Pearl River showcases a spectrum of bottom current‐induced features, including sediment wave fields, erosion fields and contourite drifts. The southern flank of the Shenhu slope is characterised by a bottom current erosion field, a non‐depositional surface, a sediment wave field and isolated mounded drifts. On the Yingqiong slope, the contourite drifts are limited to its southern flank where gravity flow action is absent, and the complex geomorphology interacts with the bottom current, forming a complex contourite depositional system. The results of this study serve as a foundational framework for further global research on bottom current circulation and hydrodynamics.

Organisation of activities in settlements of the southeastern group of the Funnel Beaker Culture. Patterns of use and deposition of lithic artefacts from Zawarża, Site 2, Pińczów commune

The aim of the study is to provide an insight in the possible modes of use of space and organization of work within the settlements of the south-eastern group of Funnel Beaker Culture (FBC SE) utilizing framework for integrating use-wear of lithic artefacts and intra-site analyses of their deposition patterns. Those analyses concerns Site 2 in Zawarża, Pińczów commune. Excavations on the site spanned from 1959 to 1963, culminating in the uncovering of 58 ares of the site, which equals approximately 60% of its supposed area. This fact along with already published set of data concerning archaeological remains, and short occupation period make it a nearly ideal candidate for testing new analytical approaches. This study utilizes traces of use recorded on 32 of the 119 flint artefacts, as well as the data on their deposition to identify possible functional areas of the site linked to butchering and related practices and other activities such as production or repairing of tools.

Glacier Retreat Induces Contrasting Shifts in Bacterial Biodiversity Patterns in Glacial Lake Water and Sediment

Glacial lake ecosystems are experiencing rapid changes due to accelerated glacier retreat. As glaciers recede, their influence on downstream habitats diminishes, potentially affecting the biodiversity of glacial lake microbial communities. However, there remains a knowledge gap regarding how bacterial biodiversity patterns in glacial lakes are altered by diminishing glacial influence. Here, we investigated shifts in bacterial communities in paired water and sediment samples collected from seven glacial lakes on the Tibetan Plateau, using a space-for-time substitution approach to understand the consequences of glacier retreat. Our findings reveal that bacterial diversity in lake water increases significantly with a higher glacier index (GI), whereas sediment bacterial diversity exhibits a negative correlation with GI. Both the water and sediment bacterial communities display significant structural shifts along the GI gradient. Notably, reduced glacial influence decreases the complexity of bacterial co-occurrence networks in lake water but enhances the network complexity in sediment. This divergence in diversity and co-occurrence patterns highlights that water and sediment bacterial communities respond differently to changes in glacial influence in these lake ecosystems. This study provides insights into how diminishing glacial influence impacts the bacterial biodiversity in glacial lake water and sediments, revealing contrasting patterns between the two habitats. These findings emphasize the need for comprehensive monitoring to understand the implications of glacier retreat on these fragile ecosystems.

Modern Pollen Signatures and Vegetation Dynamics in Northwestern Himalaya, India

ABSTRACT Palynological studies have been conducted for the first time in the Renukaji Wildlife Sanctuary (RWS), a Sal-dominated region within the foothills of Northwestern (NW) Himalaya in Himachal Pradesh, India. This research enhances our understanding of the relationship between modern pollen rain and vegetation, as well as pollen representation in sediments. Furthermore, it contributes to palaeovegetation reconstruction based on paleoclimatic trends by improving our interpretation of pollen deposition patterns. The study area was delineated into three distinct zones based on biological niche characteristics: Zone 1 (Recreation Zone), Zone 2 (Buffer Zone), and Zone 3 (Core Zone). Pollen analysis conducted on 30 surface soil samples and moss cushions, collected from all three zones, reveals the dominance of dry deciduous taxa, followed by extra-terrestrial taxa and wet deciduous taxa. Land Use Land Cover (LULC) analysis performed using satellite data reveals that Shorea robusta (Sal) mixed forest covers 32% of land, followed by Pinus spp. (8%) and their associates (25%). Shorea robusta, a mixed wet deciduous taxon and high pollen producer, exhibits low pollen counts, possibly due to chemical and microbial decomposition or low pollen dispersal efficiency. This study utilises a comparative database correlating pollen data with contemporary vegetation patterns to establish a robust framework for assessing sedimentary pollen sequences. Through this approach, we aim to elucidate past vegetation dynamics and infer climate fluctuations within the NW Himalaya.

Numerical Investigation of the Sediment Load Exchange between a Coastal Mud Bank and Its Neighbouring Estuary

Muddy coastlines cover much of the world’s shores, yet studies on the interaction between mud-affected coasts and estuaries are limited. This study focuses on the Mahury River estuary and its interaction with the muddy coast of the Guianas, primarily fed by the Amazon. A coupled wave–current–sediment transport model is developed to analyze the sediment exchange in an environment with strong interactions between the waves and the fluid mud. Simulations explore how seasonal changes in waves, mud availability, and tides affect sediment fluxes. The main processes influencing suspended particulate matter (SPM) and sediment transport are well emulated, notwithstanding the complexity of the ambient muddy environment. The results show that during the rainy season, strong wave damping and wave refraction zones cause high SPM resuspension in shallow waters (&lt;5 m). In contrast, during the dry season, wave influence shifts to the estuary mouth. Erosion and sedimentation patterns indicate that ebb currents associated with neap tides during the rainy season represent the most favourable conditions for the alongshore migration of mud banks. Neaptide ebb currents also contribute to sedimentation during the dry season but only in the estuary mouth and the nearby coastal area. The abundance of mud leads to an extension of the estuary’s intertidal area during the dry season.

Post-mortem analysis of the deposit layers on the lower divertor after the 2023 high particle fluence campaign of WEST

We analysed deposits collected on the lower divertor of WEST after the first high fluence campaign performed in 2023. Deposits were collected on the high field side (thick deposition area) of 2 ITER-grade plasma facing units (PFUs), located on different toroidal positions. Using focused ion beam cross sectioning, the deposits were found to be very thick (12–55 µm). A significant difference was observed in the toroidal direction with thicker deposits for the PFU located at the maximal heat load in the inner side, showing a deposition pattern due to the toroidal magnetic field modulation. Deposits present a complex layer-by-layer structure with dense layers, some melted parts and porosities within the layers. The deposition is mainly composed of tungsten with oxygen, boron, carbon and traces of nitrogen whose composition vary along the radial direction. We identified W-rich deposits in the high plasma flux area near the inner strike point and deposits rich in O, B, C and N in the low plasma flux area further away from this strike point. W dense layers of about 5 up to 40 µm thick in the thick deposit area near the strike point were attributed to the high fluence campaign. Pure boron layers resulting from wall conditioning and processed by plasma wall interactions were also observed.

Morphological and geological responses of barrier estuaries to dam-opening systems

River discharge depending on the dam gate operation method is an important factor underlying changes in estuarine sedimentation dynamics, but comprehensive studies are limited by data collection constraints. The hydrological operation of Nakdong Dam, designed to prevent seawater intrusion by opening during ebb tides and heavy rains and closing during flood tides, presents an ideal setting for such investigations. This study focused on the Nakdong River Estuary (NRE), utilizing aerial photography, bathymetry data, and sedimentation rate data to determine alterations in sediment transport and deposition patterns within the two tributary estuaries. Spatial discrepancies in sedimentation patterns across the eastern and western regions of the NRE were particularly evident in the spatial variations of textural characteristics and sedimentation rates. An enhanced ebb tidal prism resulting from dam gate opening in the eastern region caused the development of erosional topography and a rough depositional environment, forming a landward migrating (transgressive) barrier island system. Conversely, the predominantly closed dam gates in the western region maintained a consistent deposition pattern due to a regular tidal prism, facilitating the formation of sedimentary topography and fine sediment deposition. Consequently, barrier islands followed a seaward building (prograding) system. Therefore, the results suggested a role of modern dam gate operation as a major sedimentation mechanism, providing valuable insights for the sustainable management of estuarine sediment environments.

The tectonic implications of a rare metamorphic event in eastern China during the Earth's “middle age”

The Mesoproterozoic Era has long been considered a relatively stable, silent, and even "boring" period in Earth's history, during which the lithosphere was tectonically inactive. However, an increasing amount of evidence suggests that metamorphism and magmatism were much more widespread and intense than previously thought, implying that this period was dynamic. Here we report metamorphism around ca. 1.4 Ga along the southeastern margin of the North China Craton, eastern China. We conduct TIMA, EMPA, and zircon SHRIMP and LA-ICP-MS U-Pb dating on garnet amphibolites and their country rocks. The detailed mineral composition of a representive garnet amphibolite sample is identified and determined by TIMA. Phase equilibria modelling using pseudosections combined with EMPA data indicates the peak metamorphism stage (M 2 ) of the garnet amphibolites at a P-T condition of 10.6-11.2 kbar/820 ℃. SHRIMP Zircon U-Pb analysis yields an age of 1366 ± 17 Ma for the garnet amphibolites, which is slightly younger than that of its country rock schist (1376 ± 22 Ma). Integrating the metamorphic event with geochemical signatures, magmatic records, and sedimentation patterns in analogous geological settings on other continents, our findings collectively demonstrate a protracted and pervasive orogenic process along the periphery of the Columbia supercontinent.

Organic carbon burial dynamics at the Chukchi Shelf margin: Implications for the Arctic Ocean carbon sink

Organic carbon (OC) burial plays a crucial role in regulating the Arctic Ocean's capacity to uptake atmospheric CO₂. In this study, we demonstrate the transport, deposition, and degradation patterns of different sources of OC to reveal burial dynamics at the Chukchi Shelf margin, a region with the highest primary production in the Arctic Ocean currently affected by dramatic sea ice retreat. Observations of suspended particulate material show a pronounced separation of terrestrial and marine OC in the water column, which subsequently influences OC lateral transport and differential deposition. Easily suspendable terrestrial OC is concentrated in the upper 10 m of water or sea ice and transported to the Canada Basin, where it undergoes severe degradation of fresh carbon in the water column and uppermost sediments. In contrast, faster-settling marine OC is more likely to be buried in the canyons and at the Chukchi Shelf margin, with ice algae contributing about 14 % and 55 % of OC burial in areas south and north of 73°N, respectively, leading to higher initial burial efficiency. Increasing Arctic marine primary production could thus enhance the region's role as a carbon sink over millennial timescales, although the burial efficiency of terrestrial OC will eventually exceed that of marine OC with prolonged burial time. Our findings highlight the importance of lateral transport, differential deposition, and selective degradation in Arctic carbon burial, providing a basis for objectively assessing the future capacity of the Arctic carbon sink and its feedback to climate change.

A method to spatially assess multipass spray deposition patterns via UV fluorescence and weed population shifts

AbstractSpray deposition patterns from agricultural sprayers are traditionally sampled discretely along a field transect accounting for 0.5% or less of the treated area. Such methods may not fully capture the dimensional variability inherent in large‐scale, multiple‐pass spray applications, especially evident from an agricultural spray drone (ASD). This study investigated the utilization of UV‐fluorescent dye and nighttime aerial imaging techniques to assess large‐scale, multipass spray deposition patterns. Accuracy of digital hue from UV‐fluorescent photography to predict deposition of proxy dye was confirmed via fluorometry assessed intensity levels of extracted UV‐fluorescent dye from 384 Petri dishes placed prior to treatment. Results showed that ASD applications, regardless of nozzle type, exhibited greater spatial variability within the target area compared to ride‐on sprayer applications, primarily due to overapplication. Additionally, the ASD generated spray drift to adjacent nontarget areas that was at least three times more than that of ride‐on and spray‐gun sprayers. Multipass deposition was further assessed via in situ smooth crabgrass infestation following treatment with quinclorac or topramezone by multipass ASD or hand‐held, four‐nozzle spray boom. Weed infestation annotated from overlaid grids with 9.3‐dm2 ground resolution inconsistently detected spatial heterogeneity between transects assessed along the center and edge of each sprayer pass. The ASD controlled smooth crabgrass 11% more than the hand‐held sprayer, albeit with an 18% increase in spray drift to nontarget areas, similar to the UV‐fluorescence study. Digitally assessed average hue of fluorescence photography appears to be a viable method to assess multidimensional and continuous spatial relationships of spray deposition.

Seasonal distribution and deposition patterns of size-segregated particulate matter in human respiratory system in Central Delhi, India

Seasonal distribution and deposition patterns of size-segregated particulate matter in human respiratory system in Central Delhi, India

Three-dimensional finite element analysis of turbulent crude oil flow and solid particle deposition patterns in circular curved pipelines

This study presents a numerical investigation of turbulent crude oil flows in circular curved pipelines, with a focus on the deposition patterns of solid particles within the fluid. Simulations were conducted using the Reynolds–Averaged Navier–Stokes equations coupled with the k–ε turbulence model to examine the influence of structural characteristics, such as bend curvature angle and bend curvature radius, on flow dynamics and particle deposition. The results reveal that the complex flow patterns generated by these geometric features significantly affect pressure gradients and particle trajectories. Specifically, the study shows that turbulent flows within bends exhibit intricate behaviors, with deposition patterns being strongly influenced by the pipeline’s geometric parameters. Sand particles, commonly present in petroleum flows, are found to be more effectively transported in pipes with larger curvature angles, while they exhibit a higher propensity to settle at smaller curvature angles and larger bend curvature radii. Furthermore, the simulations indicate that the majority of deposited particles accumulate on the inner wall immediately downstream of the elbow entrance.