Surface Flow Research Articles

Application of drag-reducing polymers in forest firefighting: Effects on wood properties and mechanism study

Based on the successful utilization of polymer additives in drag reduction for long-distance transportation and the intricacies of their application in firefighting contexts, this study investigated the impact of additives on wood properties in forest fire suppression through a combination of experiments and molecular dynamics simulations, focusing on wettability, fluidity, and combustibility. Optimal concentrations of polymer solutions were determined through contact angle measurements and surface flow experiments. The effects of polymers on wood water retention, thermal stability, and microstructure were analyzed using thermogravimetric analysis, infrared spectroscopy, and wood impregnation experiments. Wetting and flow models of polymers on cellulose surfaces were simulated to elucidate the wetting mechanism and dynamic behavior of polymers during flow. The results revealed that polyacrylamide (PAM) and polyethylene oxide (PEO) promoted wood surface wetting, improved flowability, enhanced water retention, and delayed decomposition at optimal concentrations. PAM exhibited superior effects in flow stability, thermal stability, and liquid absorption enhancement, attributed to strong hydrogen bonding between PAM and surfaces, primarily through amide groups. During flow, PAM molecules gradually aggregated and moved as aggregates along the X-axis. In contrast, the PEO system relied on electrostatic forces between water and surfaces, with dynamic processes involving repeated stretching and shrinking of PEO molecular chains to facilitate water flow and enhance wetting. This research contributes to delineating the application conditions and benefits of polymer on wood surfaces, enhancing the efficacy and potential of drag-reducing agents in firefighting applications.

Multidisciplinary hydrogeochemical and isotopic assessment of the Pordenone Plain (Northeastern Italy) for water resources sustainability

This study aims to comprehensively characterize the hydro-geochemical and isotopic features of the complex groundwater system in the Pordenone Plain (northeastern Italy). The area is an important industrial and agricultural area exposed to severe anthropogenic pressure and climate change, which put its water resources at risk in terms of quantity and quality, making it of high scientific and social interest. The hydrogeological setting of the Pordenone Plain has been previously simplified as a phreatic continuous aquifer in the High Plain that changes into a multilayered aquifer system towards the Low Plain. However, this study reveals significant lithological and structural heterogeneities in the High Plain that exert a strong influence on its subsurface hydrodynamics. All waters exhibit a Ca(Mg)–HCO3 composition with relatively high Na–K values in the aquifers of the Low Plain likely related to cation exchange processes. Water stable isotopes (δ2H–H2O and δ18O–H2O) indicate that the deep aquifers in the Low Plain are confined by impermeable geological formations, such as clays and siltstones, which entirely restrict water mixing with shallower aquifers. Concurrently, tritium analysis provides evidence of slow recharge and flow rate. Three primary groundwater flows have been identified within the plain, as follows: 1) a surface flow that affects the unconfined or semi-confined aquifers of the High Plain hosted in gravelly sediments; 2) an intermediate flow fed by the pedemontane zone, which includes unconfined deep aquifers of the High Plain, semi-confined/shallow aquifers (at a depth of 40–50 m) located near the resurgence belt area and karst springs located in eastern pedemontane of the Cansiglio Plateau; 3) a deep flow fed by the mountainous zone that affects the deep confined aquifers of the Low Plain. A reliable hydrogeochemical conceptual model has been developed to explain the compositional variability of the studied waters, providing valuable insights for the sustainable management of groundwater resources in the Pordenone Plain.

Phosphorus removal in surface flow treatment wetlands for domestic wastewater treatment: Global experiences, opportunities, and challenges

Treatment Wetlands (TWs) are widely used for the treatment of domestic wastewater, with an increasing emphasis on provision of multiple co-benefits. However, concerns remain regarding achieving stringent phosphorus (P) discharge limits, system robustness and resilience, and associated guidance on system design and operation. Typically, where P removal is intended with a passive TW, surface flow (SF) systems are the chosen design type. This study analysed long-term monitoring datasets (2–30 years) from 85 full-scale SF TWs (25 m2 to 487 ha) treating domestic sewage with the influent load ranging from 2.17 to 54,779 m3/d, including secondary treatment, tertiary treatment, and combined sewer overflows treatment. The results showed median percentage removals of total P (TP) and orthophosphate (Ortho P) of 28% and 31%, respectively. Additionally, median areal mass removal rates were 5.13 and 2.87 gP/m2/yr, respectively. For tertiary SF TWs without targeted upstream P removal, 80% of the 44 systems achieved ≤3 mg/L annual average effluent total P. Tertiary SF TWs with targeted upstream P removal demonstrated high robustness, delivering stable effluent TP < 0.35 mg/L. Seasonality in removal achieved was absent from 85% of sites, with 95% of all systems demonstrating stable annual average effluent TP concentrations for up to a 30-year period. Only two out of 32 systems showed a significant increase in effluent TP concentration after the initial year and remained stable thereafter. The impact of different liner types on water infiltration, cost, and carbon footprint were analysed to quantify the impact of these commonly cited barriers to implementation of SF TW for P removal. The use of PVC enclosed between geotextile gave the lowest additional cost and carbon footprint associated with lining SF TWs. Whilst the P-k-C* model is considered the best practice for sizing SF TWs to achieve design pollutant reductions, it should be used with caution with further studies needed to more comprehensively understand the key design parameters and relationships that determine P removal performance in order to reliably predict effluent quality.

Large Eddy Simulation of Cross‐Shore Hydrodynamics Under Random Waves in the Inner Surf and Swash Zones

AbstractA 3D large eddy simulation coupled with a free surface tracking scheme was used to simulate cross‐shore hydrodynamics as observed in a large wave flume experiment. The primary objective was to enhance the understanding of wave‐backwash interactions and the implications for observed morphodynamics. Two simulation cases were carried out to elucidate key processes of wave‐backwash interactions across two distinct stages: berm erosion and sandbar formation, during the early portion of a modeled storm. The major difference between the two cases was the bathymetry: one featuring a berm without a sandbar (Case I), and the other, featuring a sandbar without a berm (Case II) at similar water depth. Good agreement (overall Willmott's index of agreement greater than 0.8) between simulations and measured data in free surface elevation, wave spectrum, and flow velocities validated the model skill. The findings indicated that the bottom shear stress, represented by the Shields parameter, was significant in both cases, potentially contributing substantial sediment transport. Notably, the occurrence of intense wave‐backwash interactions were more frequent in the absence of a sandbar. These intense wave‐backwash interactions resulted in a pronounced horizontal pressure gradient, quantified by high Sleath parameters, exceeding the criteria for momentary bed failure. Additionally, a more vigorous turbulence‐bed interaction, characterized by near‐bed turbulent kinetic energy, was observed in the case lacking a sandbar, potentially augmenting sediment suspension. These insights are pivotal in understanding the mechanisms underlying berm erosion and how sandbar formation serves to protect further beach erosion.

Prediction–correction projection immersed interface method for interfacial stress-induced flows and applications to electrohydrodynamics

We propose a robust, high-resolution prediction–correction projection immersed interface method (IIM) for solving the unsteady incompressible Navier–Stokes equations with traction boundary conditions, which arise from free surface flows driven by capillary, electric, and elastic forces. This method combines the advantages of traditional body-fitted moving mesh methods and immersed boundary methods (IBM), allowing for the accurate imposition of boundary conditions on free surfaces using Cartesian grids and providing detailed interface information that is typically smoothed out in traditional IBM. The irregular liquid-phase domain is embedded within a square region and discretized using a dynamically adaptive Cartesian mesh. The free surface is captured using a narrow-band level set with hybrid reinitialization. A prediction–correction projection scheme is constructed, incorporating additional pressure predictions and corrections to enhance robustness. The resulting Helmholtz/Poisson equations are solved using the augmented IIM for boundary value problems. Grid refinement analysis demonstrates second-order convergence of the L∞ error, even in challenging cases such as the oscillating drop test with low viscosity. We further apply this method to electrohydrodynamic (EHD) problems, constructing an implicit augmented IIM to solve the equations governing the electric field and charge conservation. Numerical experiments demonstrate that this method accurately addresses highly intense EHD phenomena, such as the formation of Taylor cones, highlighting its robustness.

ESTIMATION OF LENGTH AND SLOPE FACTOR (LS) AS EROSION PREDICTION IN WAY PUBIAN SUB WATERSHED

Erosion caused by land degradation is one of the main challenges to soil quality around the world. One way to prevent erosion is by analyzing the length and slope factor (LS). The increasing length of the slope causes the higher amount of cumulative runoff and also the increasing steepness of the soil slope causes the higher speed of runoff that contributes to erosion. The purpose of this research is to analyze the LS factor value of Moore and Burch (1986) method and LS Nomograph for Way Pubian Subwatershed. The research method was done with Moore and Burch method and Nomograf LS. Moore and Burch (1986) method used the flow accumulation on DEM data as the main input in ArcGIS and the result shows the LS value ranged from 0 to 765.625 with an average (mean) value of 4.427. Meanwhile, the nomograph LS method resulted in high LS values and is not compatible with the Jakarta RTL-RLKT Preparation Implementation Guidelines (1986). Slope conditions affect the amount of surface flow so that it also affects the contribution of erosion and LS value. Way Pubian sub-watershed also classified as steep, resulting in a high LS value. Based on the method of Moore and Burch (1986) using ArcGIS software, we can conclude that the results of LS factor values can be used in Indonesia compared to the nomograph LS method which the results are less suitable due to topographic factors. As a result, the LS value from Moore and Burch (1986) method can be used in erosion prediction calculation.

The Effectiveness of Public Green Open Space Capabilities in Reducing Flooding

The Palopo City watershed could not accommodate the high discharge of rainfall that had fallen previously. The Green Open Space (GOS) had an ecological function by absorbing rainwater. Urban green open spaces absorbed surface flow water in the past, reducing the risk of flooding. In the past, this research measured the effectiveness of three green open spaces (Islamic Center, Pancasila Field, and Salubulo Field) in reducing flooding in Palopo City. We collected data on vegetation types, infiltration capacity, and runoff discharge. Data analysis involved the analysis of infiltration capacity (F), runoff discharge (Q), and green open space effectiveness. In the three green space locations, the following vegetation types were found: Katapang (Terminalia catappa), Palm (Dypsis lutescens), Trambesi (Samanea Saman), and Grass (Cyperus rotundus). The highest total infiltration capacity in the Salubulo Field Green Space resulted in 155 m3/hour (fast category). In the past, the most significant runoff discharge's total value was GOS Pancasila Field: 713.4 mm3/minute. The study concluded that the Salubulo Field Green Space had the highest infiltration capacity (160 m3/hour) and runoff discharge (69 mm3/minute), making it the most effective in reducing flooding in Palopo City in the past. This was &gt; 1 (effectiveness criteria achieved), and the space was dominated by vegetation (trees and grasses).

Can rock surface flow derived from outcrops generate surface runoff in a rocky desertified area?

Rock surface flow, formed from exposed rock surfaces, is a unique form of runoff in rocky desertified areas with massive bedrock outcrops. The question of whether the rock surface flow promotes surface runoff formation continues to puzzle us. To address this problem, four sites with notable bedrock outcrops and different land use types were selected from a typical desertified area in Guizhou, China. Straight and concave rock-surface shapes that were the most capable of collecting rainwater were selected at each site. Soil infiltration and water storage capacity experiments were conducted to observe the infiltration and water storage properties of the soil closely adhering to the rock–soil interface (CRSI) of the bedrock outcrops by taking the soils far from the outcrops horizontally (FRSI) as the control, and to further explain the conditions for surface runoff formation via rock surface flow. Our results showed that the CRSI is more prone to producing surface runoff than the FRSI, which is attributed to its lower infiltration (stable infiltration rate of 0.2 to 192.6 mm/min) and water storage capacity (total reservoir 441.6 to 613.6 t/hm2) than that of FRSI (4.50 to 272.8 mm/min, 458.8 to 635.4 t/hm2). This phenomenon would be intensified after receiving the rock surface flow input. Concurrently, concave rock surfaces are more likely to promote surface runoff formation than straight rock surfaces, which are affected by the accumulation of rock surface shapes on rainwater. A discriminating condition for whether rock surface flow produces surface runoff at the CRSI is proposed based on the inversely proportional functional relationship between rainfall (rainfall intensity RI and amount RA) and the effective rock surface rainfall catchment area (ARS). When RI or RA exceeds the critical threshold, the surface runoff with mechanisms of excess infiltration or excess saturation is generated around bedrock outcrops. The discriminating equation will help increase surface runoff prediction accuracy in rocky desertified areas with exposed bedrock outcrops. These results help understand the importance and role of rock surface flow hydrologic processes in karst areas.

Turbulence approaches for numerical predictions of vehicle-like afterbody vortex flows

The numerical prediction of aerodynamic characteristics for vehicles is crucial to both industry and academia, with various numerical approaches playing a critical role in accurately resolving flow fields. This study aims to evaluate the effectiveness of three typical numerical approaches, including RANS, IDDES, and LES in predicting the afterbody vortex flows of a generic model, specifically a slanted-base cylinder. This study involved analyzing aerodynamic coefficients, time-averaged surface flow, time-averaged surrounding flow and transient flow, revealing the capabilities of each approach. RANS offers acceptable accuracy in predicting time-averaged aerodynamic coefficients and surface flow patterns, though it falls short in capturing time-varying physical quantities. LES, despite its higher computational cost, provides a more accurate prediction for both time-averaged and transient flow behaviors, particularly in capturing flow instabilities and multi-scale fluctuations. IDDES can be prioritized when a rough understanding of transient characteristics is sufficient. This study highlights the unique strengths and limitations of three typical numerical approaches in predicting vehicle-like afterbody vortex flows, guiding the selection of appropriate methods based on specific research needs.

Influence of bioinspired morphing on the flow field characteristics of UAV wings at low Reynolds number

The aerodynamic performance of unmanned aerial vehicles (UAV) can be improved by optimizing the surface flow characteristics over a wide range of angle of attack (AoA) through novel mechanisms. Recently, the bioinspired camber morphing concept has received greater attention because of the proven ability of nature species towards the retention of aerodynamic performance under different environmental conditions. In particular, birds like Eagles ( Accipitriformes) increase their wing camber in the course of flight to achieve maximum climbing altitude with good manoeuvring capability. The biomimetic designs such as the corrugated bone structure of Eel fish ( Anguilliformes) helps to achieve the wing camber morphing with optimal aerodynamic load distributions. The present work is focused on the bioinspired variable camber morphing (VCM) strategy to enhance the flow control behaviour and aerodynamic forces for a specific UAV wing configuration at various AoA. Here, NACA 4412 airfoil is used as a baseline wing configuration and the camber morphing mechanisms which are derived through Eel fish and Eagle are analysed. The model with Eagle wing morphing (EWM) mechanism is considered as a primary case of VCM and Eel fish’s corrugated structure is taken as a secondary case of VCM model. The coefficient of lift ( C L ), coefficient of drag ( C D), coefficient of pressure ( C p) and endurance factor are estimated for both morphed and baseline wing configurations through high fidelity numerical simulations. Interestingly, it is observed that the EWM wing configuration has excellent surface flow control characteristics than the CSM wing configuration and the results are presented with a detailed discussion.

Novel humanized monoclonal antibodies against ROR1 for cancer therapy

BackgroundOverexpression of receptor tyrosine kinase-like orphan receptor 1 (ROR1) contributes to cancer cell proliferation, survival and migration, playing crucial roles in tumor development. ROR1 has been proposed as a potential therapeutic target for cancer treatment. This study aimed to develop novel humanized ROR1 monoclonal antibodies and investigate their anti-tumor effects.MethodsROR1 expression in tumor tissues and cell lines was analyzed by immunohistochemistry and flow cytometry. Antibodies from mouse hybridomas were humanized by the complementarity-determining region (CDR) grafting technique. Surface plasmon resonance spectroscopy, ELISA assay and flow cytometry were employed to characterize humanized antibodies. In vitro cellular assay and in vivo mouse experiment were conducted to comprehensively evaluate anti-tumor activity of these antibodies.ResultsROR1 exhibited dramatically higher expression in lung adenocarcinoma, liver cancer and breast cancer, and targeting ROR1 by short-hairpin RNAs significantly inhibited proliferation and migration of cancer cells. Two humanized ROR1 monoclonal antibodies were successfully developed, named h1B8 and h6D4, with high specificity and affinity to ROR1 protein. Moreover, these two antibodies effectively suppressed tumor growth in the lung cancer xenograft mouse model, c-Myc/Alb-cre liver cancer transgenic mouse model and MMTV-PyMT breast cancer mouse model.ConclusionsTwo humanized monoclonal antibodies targeting ROR1, h1B8 and h6D4, were successfully developed and exhibited remarkable anti-tumor activity in vivo.

Simulasi Jaringan Drainase Kawasan Desa Lubuk Suli Kec. Depati VII Kabupaten Kerinci Menggunakan Program EPA SWMM Versi 5.1

One of the areas in Kerinci Regency that is often hit by floods is Lubuk Suli Village. Flooding was caused by overflowing water from the Batang Marao river. The main objective of this research is to provide information to the relevant government about good drainage for the Lubuk Suli Village Area using existing data and planning data by simulating the capability of the Drainage Network for the Lubuk Suli Village Area using the EPA SWMM 5.1 program. The data used in this research are land use maps to determine the percentage of impervious area, rainfall data and drainage channel dimension data in the area. The rain data series used is hourly rain data. Due to the absence of hourly rainfall data at the rain station at the research location, hourly rainfall distribution was determined by changing the Intensity-Duration-Frequency (IDF) curve for a 5 year return period into a planned rainfall hyetograph using the Alternating Block Method (ABM). After all parameters have been input into EPA SWMM 5.1. Simulation can be done. The simulation quality is quite good if the continuity error for surface runoff and flow tracing is &gt; 10%. The simulation carried out in this research is divided into 2 scenarios, namely with existing data and additional storage. From the simulation results, it was found that in the 2 scenarios, the number of flood points in the simulation for scenario 1 was 6 points and in scenario 2 there were 5 points. This shows that the drainage planning design for the Lubuk Suli Village area has not been able to overcome the existing drainage load in the area.

A multi‐site and hypothesis‐driven approach to identify controls on the bedload transport regime of an anthropised gravel‐bed river

AbstractUnderstanding the effects of human disturbance on the bedload transport regime of anthropised rivers is a topic of growing importance, as such information is of interest for adequate river diagnosis, correct implementation of restoration measures and appropriate design of post‐action monitoring programs. However, such assessments are complex, especially in sites where multiple factors simultaneously influence the bedload transport regime, so that it is difficult to establish simple causal relationships between human disturbances and changes in the sediment transport regime, notably on bedload. To overcome this, there is a need for rigorous hypothesis‐driven approaches to assess the isolated effects of each driver. With this in mind, we have characterised the dynamics of bedload transport in the Upper Garonne (Central Pyrenees, Spain‐France), a river impacted by sediment retention, flow diversion and mining that influence its morphological conditions and transport regime. We assessed the effects of (1) surface grain size distribution, (2) river morphology, (3) sediment supply and (4) flow diversion on the bedload transport regime. Four sites with different degrees of river anthropisation were selected. After defining hypotheses on the most likely bedload transport conditions for each site, we proposed a set of discriminating criteria to test these hypotheses, based on temporal within‐site and spatial between‐site comparisons of coarse particle tracking measurements over four years. The results of this research showed that the hydrosedimentary regime of the Garonne is controlled by a complex combination of drivers such as valley physiography, which exerts a first‐order control on differences in reach‐scale bedforms and bedload dynamics; and human disturbances which contribute to a reduction in sediment supply through changes in land cover and hydropower dams, or to changes in hydrology (i.e., flow competence) due to water diversion and abstraction.

Impact of Lean-Burn Combustor Flow on Nozzle Guide Vane Performance

Abstract In this paper we investigate the impact of lean-burn-representative swirl and temperature distortion on the aerothermal performance of fully-cooled high-pressure nozzle guide vanes (NGVs) from a modern aero-engine. Experiments were carried out in the Engine Component AeroThermal (ECAT) facility at the University of Oxford. This is a fully-annular warm-flow engine parts facility, designed to operate at engine-representative conditions of Reynolds and Mach number. Inlet profiles of swirl, turbulence, and non-dimensional total temperature were generated using a non-reacting combustor simulator. The NGV outlet flow was experimentally characterized at three downstream planes in experiments with and without lean-burn-representative inlet conditions. Area-survey measurements included distributions of whirl angle, kinetic energy (KE) loss, and non-dimensional total temperature. Experimental data is compared to computational fluid dynamics (CFD) simulations. Fully-featured NGV geometry (including film cooling holes and internal passages) was used, to account for internal cooling flow redistribution resulting from altered external loading. We show that lean-burn inlet conditions result in significant surface flow redistribution, relatively high levels of residual swirl in the downstream flow, and a small increase of integrated KE loss.

QGIS‐based support tools to simplify the complex design challenges of subsurface drainage systems

AbstractWe developed a comprehensive set of tools to simplify the design and layout of subsurface drainage systems. These tools, which utilize publicly available LiDAR (light detection and ranging) datasets, may also be used for other applications. The tool streamline operations include harmonizing geographic information system (GIS) layers into a single State Plane or Universal Transverse Mercator Coordinate System, clipping and thinning LiDAR data within a defined boundary, generating drainage networks with contour lines and laylines for surface flow visualization, identifying depressions and creating gridlines with user‐specified angles and spacings. To showcase their use, an illustrative example using a diverse dataset from the University of Illinois’ South Farm is provided. These user‐friendly tools, optimized for compatibility with all versions of QGIS3 (quantum geographic information system 3), are freely accessible for download or installation from the official QGIS plugin repository. A user manual with step‐by‐step instructions is available online on the Illinois Drainage Guide website.

Evaluating surface and subsurface fluxes in hydrological models to advance basin-scale operational water supply forecasting

ABSTRACT Comprehensive assessments of hydrological components are crucial for enhancing operational water supply simulations. However, hydrological models are often evaluated based on their surface flow simulations, while the validation of subsurface and groundwater components tends to be overlooked or not well documented. In this study, we evaluated the outputs of two hydrological models, the Large Basin Runoff Model (LBRM) and the Weather Research and Forecasting – Hydrological modeling extension package (WRF-Hydro), for potential implementation in operational water balance forecasting in the Great Lakes region. We examined the simulated hydrological variables including surface (e.g. snow water equivalent, evapotranspiration, and streamflow), subsurface (e.g. soil moisture at different layers), and groundwater components with observed or reference data from ground-based stations and remotely sensed images. The findings of this study provide valuable insights into the capabilities and limitations of each model. These findings contribute to more informed water management strategies for the Great Lakes region.

Numerical Study on Auxiliary Propulsion Performance of Foldable Three-Element Wingsail Utilizing Wind Energy

Sail-assisted propulsion is an important energy-saving technology in the shipping industry, and the development of foldable wingsails has recently become a hot topic. This type of sail is usually composed of multiple elements, and its performance at different folding configurations is very sensitive to changes in incoming airflow, which result in practical operational challenges. Therefore, original and optimized three-element wingsails (bare and concave) are modeled and simulated using the unsteady RANS method with the k-ω SST turbulence model. Next, certain key design and structural parameters (such as angle of attack, apparent wind angle, and camber) are employed to characterize the auxiliary propulsion performance, and the differences are explained in combination with the flow field details. The results show that, in the unfolded state, the aerodynamic performance of the concave wingsail is better than that of the bare wingsail, exhibiting higher lift coefficients, lower drag coefficients, and a more stable surface flow. In the fully folded state, wherein both the nose and flap are rotated, the thrust performance of the concave wingsail remains superior. Specifically, at an angle of attack of 8 degrees, the thrust coefficient of the concave wingsail is approximately 23.5% higher than that of the bare wingsail, indicating improved wind energy utilization. The research results are of great significance for engineering applications and subsequent optimization design.

Abstract We074: Macrophages Endocytose the Extracellular Matrix Component Hyaluronan

Background: Following myocardial infarction, macrophages clear cellular debris during remodeling of the extracellular matrix (ECM). The presence of macrophages coincides with a significant increase in the ECM component hyaluronan (HA). HA is produced in copious amounts following injury, such as myocardial infarction, and HA may interfere with myocardial wound healing. Because macrophages express hyaluronan receptors and are known to facilitate ECM remodeling, it is possible that macrophages remove HA early after MI. The extent to which macrophages clear HA is not known. Goal: To determine the extent to which macrophages endocytose hyaluronan (HA). Methods and Results: Bone marrow derived macrophages (BMDMs) were polarized into a pro-inflammatory (M1) phenotype using LPS and INF-g, or pro-reparative phenotype (M2) using IL-4 and IL-13. In addition to the polarization factors, cells were treated with 5,000 ng/ml of a fluorescein-labeled HA or a vehicle for 24 hours. At the time of collection, cells were stained with trypan blue to quench surface fluorescence and flow cytometry was used to measure the uptake of labeled HA. An increase in cellular fluorescence intensity after HA treatment indicates the extent of endocytosis of HA. Mean fluorescence intensity (MFI) values were recorded and used to calculate the change in fluorescence between the treated and control groups (DMFI). A significant increase in DMFI was observed when both M1 and M2 macrophages were compared to naïve (M0) controls. Conclusion: Macrophages endocytose HA, and polarized macrophages endocytose HA at a greater level than naïve macrophages. Hence, polarized macrophages may play a role in clearing HA in the heart following injury. We speculate that enhancement of macrophage-mediated clearance of HA may improve acute scar formation following myocardial infarction.

A scalable method to model large suspensions of colloidal phoretic particles with arbitrary shapes

Phoretic colloids self-propel thanks to surface flows generated in response to surface gradients (thermal, electrical, or chemical), that are self-induced and/or generated by other particles. Here we present a scalable and versatile framework to model chemical and hydrodynamic interactions in large suspensions of arbitrarily shaped phoretic particles, accounting for thermal fluctuations at all Damkholer numbers. Our approach, inspired by the Boundary Element Method (BEM), employs second-layer formulations, regularized kernels and a grid optimization strategy to solve the coupled Laplace-Stokes equations with reasonable accuracy at a fraction of the computational cost associated with BEM. As demonstrated by our large-scale simulations, the capabilities of our method enable the exploration of new physical phenomena that, to our knowledge, have not been previously addressed by numerical simulations.

Predesign of an Urban Rainfall Drainage Network with Genetic Algorithms

The pre-design of an urban storm drainage network is proposed with an optimization method consisting of two parts: in one part, the connection of the manholes is proposed so that there is little water flow in the pipes; in the other part, it is based on a genetic algorithm to find the lowest cost of acquisition of the pipes and of the excavation necessary for their installation, complying with several hydraulic and constructive restrictions recommended in construction manuals of networks of this type. The described procedure is made from the linking of the pipes that make up the network (network layout) trying to obtain the smallest sum of the lengths. It is considered that the conduits are of circular section, where their diameters only take commercial values. The slope of each pipe in the network is calculated so that the hydraulic depth of the water flow is 80% of the pipe diameter, in order to approximate the flow conduction capacity of the liquid within it. Finally, its application to a real case is demonstrated, and the hydraulic performance of the pre-designed network is evaluated by simulating the non-permanent free surface flow in the network using the EPA-SWMM 5.1.015 model, in order to ensure that the hydraulic restrictions and assumptions made for permanent flow are met.