High Flow Rates Research Articles

Safety and efficacy of a temperature-controlled ablation system for ventricular tachycardia: Results from the TRAC-VT study.

Catheter ablation using radiofrequency (RF) energy is an established treatment for ventricular tachycardia (VT). Tissue temperature is a key determinant of successful lesion creation, and yet, it is difficult to measure during conventional RF ablation because of the cooling effect of high-flow rate saline irrigation. The TRAC-VT study evaluated the safety and efficacy of a novel irrigated RF ablation system modulating power based on real-time tissue temperature. Patients with sustained monomorphic VT and structural heart disease (SHD) were enrolled. Catheter ablation was performed in temperature-control mode (irrigation 8 ml/min, temperature set-points 55 or 60 °C, and power output ≤ 50 W), with RF applications for ≤ 45 s. The primary safety endpoint was a composite of cardiovascular-specific serious procedure-related adverse events within 30 days post-ablation. The primary effectiveness endpoint was acute success (i.e., non-inducibility of all clinically relevant VTs). Thirty-eight patients were enrolled with monomorphic VT (age 68 ± 12 years and 84% male), with an average of 1.7 ± 1.2 VTs targeted per patient. In total, 41 ± 23 RF applications per patient were delivered. Acute procedural success was 100% (95% CI, 91-100%). No primary safety endpoints were observed. Six-month follow-up was completed in 92% of patients with 81% (95% CI, 65-91%) freedom from sustained or treated VT. A repeat ablation was performed in three patients. Ablation of VT in SHD, using a temperature-controlled irrigated RF catheter, was safe and effective with a low rate of VT recurrence at 6 months.

Analysis of blade's chord length with NACA0015 profile for enhanced wave energy conversion of Wells turbine

This paper investigates the enhancement of Wells turbine blades by modifying the chord length design parameter. The Wells turbine, a promising device in wave energy conversion systems, faces a limited operating range due to flow separation, which restricts its efficiency at higher flow rates. Enhancing the performance of the Wells turbine is crucial for effective wave energy exploitation. The computational simulations in this study are conducted using ANSYS Fluent. Turbine performance is evaluated based on non-dimensional torque, pressure torque, and efficiency, derived from solving the steady 3D incompressible Reynolds Averaged Navier–Stokes equations. The results are validated against reliable references, showing good agreement. The numerical findings reveal that altering the turbine chord length significantly impacts efficiency. Optimizing the chord length enhances the Wells turbine's performance in wave energy conversion, making it a more viable option for renewable energy power generation.

Drop Dynamics during Condensation on Superhydrophobic Surfaces in Vapor Shear Flow.

Accurate models for predicting drop dynamics, such as maximum drop departure sizes, are crucial for estimating heat transfer rates during condensation on superhydrophobic (SH) surfaces. Previous studies have focused on examining the heat transfer rates for SH surfaces under the influence of gravity or vapor flowing over the surface. This study investigates the impact of surface solid fraction and texture scale on drop mobility in a condensing environment with a humid air flow. Experiments recorded condensation with varying surface feature sizes from micro- to nano scale under different flow rates. Video analysis detected the drop-size distribution and maximum drop departure sizes. Particle image velocimetry (PIV) provided accurate shear force representations. Results showed that the maximum drop departure sizes decreased with lower surface solid fractions and higher flow rates. A force balance analysis revealed that coalescence-induced drop jumping aids drop departure. Different drop behaviors due to coalescence were linked to surface characteristics. The study quantified drop jump distances under shear force during condensation on SH surfaces, and found that jump distances increased when coalescing drop sizes were similar. Based on these findings, a method for tuning SH surfaces to control drop size at coalescence and departure was suggested. Drop mobility was measured in terms of Bond and Capillary numbers, showing a dependence on surface solid fraction and pitch size. By combining these into surface slip length, it was shown that drop mobility increases with increasing slip length.

Flow environment affects nutrient transport in soft plant roots.

This work estimates Michaelis-Menten kinetics parameters for nutrient transport under varying flow rates in the soft roots of Indian mustard (Brassica juncea) using a plant fluidic device. To find the metallic components within the roots, inductively coupled plasma mass spectrometry (ICP-MS) analysis was performed. The flow rate-dependent metabolic changes were examined using Raman spectral analysis. In addition, three-dimensional numerical simulations were conducted to assess mechanical stresses resulting from the concentration difference that enhances osmotic pressure and flow loading at the root-liquid interface. Convection, the primary mode of nutrient transport in flowing media, was observed to reduce nutrient uptake at higher flow rates. In contrast, diffusion became more prevalent in areas where the complex root structure restricted the flow field. The concentration gradient between the upstream and downstream regions of the root caused nutrient diffusion from downstream to upstream. As seen, an increase in flow rate resulted in a decrease in root length due to the reduction of advantageous metabolites, which led to lower average mechanical stress and osmotic pressure loading. Additionally, osmotic pressure at the root-liquid interface was found to increase over time. Numerical simulations revealed that the average internal mechanical stress was substantially greater when osmotic pressure was considered. This emphasizes the importance of accounting for osmotic pressure when assessing mechanical stress in roots. This study uses a fluidic device that replicates hydroponic conditions for the first time in order to evaluate the convection-dependent Michaelis-Menten kinetics of nutrient uptake in plant roots.

Achieving up to 95% removal efficiency of chlorpyrifos pesticide using sugarcane bagasse-based biochar alginate beads in a continuous fixed-bed adsorption column.

Pesticide contamination in wastewater poses a significant environmental challenge, driven by extensive agricultural use. This study evaluates the removal of chlorpyrifos (CPS) using sugarcane bagasse-based biochar alginate beads in a continuous fixed-bed adsorption column, achieving a remarkable 95-98% removal efficiency. Compared to conventional adsorbents like activated carbon, which typically show CPS adsorption capacities ranging from 50-70 mg g⁻1 under similar conditions, the biochar alginate beads demonstrate better performance with a sorption capacity of 91.93 mg g⁻1. Fixed-bed column (FBC) experiments demonstrated optimal CPS removal at 10 ppm concentration, 5 cm bed height and a flow rate of 25 mL min⁻1. The Yoon-Nelson Model exhibited the best fit, with high correlation coefficients (R2 = 0.80 to 0.98), low Akaike's Information Criterion (AIC) and Sum of Square Error (SSE) values, confirming its predictive accuracy. The model predicted a CPS removal efficiency of 95-98% and a sorption capacity of 91.93 mg g⁻1. The immobilization process using sodium alginate not only provided structural integrity to the biochar alginate beads but also improved their surface area and functional groups, significantly enhancing the adsorption dynamics. An inverse relationship between breakthrough time (τcal) and flow rate was observed, indicating improved adsorption dynamics at higher flow rates. SEM analysis revealed a porous biochar structure with significant surface area (131.09 m2/g) and pore volume (0.165 cm³/g), contributing to its high adsorption efficiency. XRD analysis indicated the partial crystalline nature of the biochar alginate beads, influenced by the presence of alginate. Additionally, breakthrough curves suggested a rapid initial uptake followed by a plateau, highlighting the material's fast adsorption kinetics. Biochar alginate beads for pesticide adsorption demonstrated good results in the scale-up investigation. This research demonstrates the potential of biochar-based adsorbents for efficient and scalable pesticide remediation in contaminated water systems, underscoring the unique contributions of alginate-immobilized biochar in enhancing performance.

Diffusion Characteristics of Dissolved Gases in Oil Under Different Oil Flow Circulations

The prediction of dissolved gas concentrations in oil can provide crucial data for the assessment of power transformer conditions and early fault diagnosis. Current simulations mainly focus on the generation and accumulation of characteristic gases, lacking a global perspective on gas diffusion and dissolution. This study simulates the characteristic gases produced by typical faults at different flow rates. Using ANSYS 2022 R1 simulation software, a gas–liquid two-phase model is established to simulate the flow and diffusion of characteristic gases under fault conditions. Additionally, a fault-simulation gas production test platform was built based on a ±400 kV actual converter transformer. The experimental data show good consistency with the simulation trends. The results indicate that the diffusion of dissolved gases in oil is significantly affected by the oil flow velocity. At higher flow rates, the characteristic gases primarily move within the oil tank along with the oil circulation, leading to a faster rate of gas dissolution in oil and a shorter time to reach equilibrium within the tank. At lower flow rates, the diffusion of characteristic gases depends not only on oil flow circulation but also on self-diffusion driven by concentration gradients, resulting in a nonlinear change in gas concentration across various monitoring points.

Study of Rewetting Behavior in AHWR Fuel Cluster During Loss of Coolant with Water Jet Impingement

This study investigates the rewetting behavior of an Advanced Heavy Water Reactor (AHWR) fuel rod bundle during a loss-of-coolant accident using computational fluid dynamics simulations with ANSYS CFX. The analysis focuses on the cooling effectiveness of radial jet impingement at varying flow rates and its impact on rewetting temperature and wetting delay. Simulations were conducted by maintaining a constant initial wall temperature, with cooling curves and contour profiles extracted from various angular positions along the axial rod surfaces. The results reveal that rewetting is faster near the jet sections due to enhanced coolant interaction, while areas farther from the jets exhibit delayed wetting and elevated wall temperatures, where vapor accumulation hinders heat dissipation. Higher flow rates minimize wetting delays and improve cooling by promoting transition and nucleate boiling. However, irregular coolant splashing and vapor dominance disrupt the uniformity of rewetting across the bundle. The study highlights the limited impact of increased flow rates on achieving consistent rewetting along the entire rod length, with substantial fluctuations observed in cooling performance at different vertical positions. The findings emphasize the need for further research under high-temperature steam conditions to better understand boiling mechanisms and improve the stability of emergency cooling systems in nuclear reactors.

Enhance Oil Recovery in Fracture-Cave Carbonate Reservoirs Using Zwitterion-Anionic Composite Surfactant System

The carbonate fracture-cave reservoir in the Tahe oilfield, China, encounters development challenges because of its substantial burial depth (exceeding 5000 m). Its characteristics are low permeability, pronounced heterogeneity, extensive karst cavern systems, diverse connection configurations, and intricate spatial distribution. Prolonged conventional water flooding leads to predominant water channels, resulting in water channeling and limited sweep efficiency. Surfactant flooding is usually adopted in these conditions because it can mitigate water channeling and enhance sweep efficiency by lowering the interfacial tension (it refers to the force that is generated due to the unbalanced molecular attraction on the liquid surface layer and causes the liquid surface to contract) between oil and water. Nonetheless, the Tahe oilfield is a carbonate reservoir where surfactant is prone to loss near the well, thereby limiting its application. High-pressure injection flooding technology is an innovative method that utilizes injection pressure higher than the formation rupture pressure to alter reservoir permeability, specifically in low-permeability oil fields. Because of the high fluid flow rate, the contact time with the interface is decreased, enabling the ability for surfactants to reach the deep reservoir. In this article, based on the mixed adsorption mechanism of two surfactants and the hydrophilic and lipophilic equilibrium mechanisms, a set of high-temperature and high-salinity resistance surfactant systems appropriate for the Tahe oilfield is developed and its associated performance is evaluated. An oil displacement experiment is carried out to examine the effect of surfactant flooding by high-pressure injection. The results demonstrate that the ideal surfactant system can lower the interfacial tension to 10−2 mN/m and its capacity to reduce the interfacial tension to 10−2 mN/m after different aging periods. Besides, the surfactant system possesses excellent wettability (wetting angle changed from 135° to 42°) and certain emulsifying abilities. The oil displacement experiment shows that the oil recovery rate of surfactant flooding by high pressure reaches 26%. The effect of surfactant flooding by high-pressure injection is better than that of high-pressure injection flooding.

Development of CPAP Overlay Interfaces for Efficient Administration of Aerosol Surfactant Therapy to Preterm Infants

The administration of surfactant aerosol therapy to preterm infants receiving continuous positive airway pressure (CPAP) respiratory support is highly challenging due to small flow passages, relatively high ventilation flow rates, rapid breathing and small inhalation volumes. To overcome these challenges, the objective of this study was to implement a validated computational fluid dynamics (CFD) model and develop an overlay nasal prong interface design for use with CPAP respiratory support that enables high efficiency powder aerosol delivery to the lungs of preterm infants when needed (i.e., on-demand) and can remain in place without increasing the work of breathing compared with a baseline CPAP interface. Realistic in vitro experiments were first conducted to generate baseline validation data, and then the CFD model, once validated, was used to explore key design parameters across a range of preterm infant nose-throat geometries and aerosol delivery conditions. The most important factors for efficient aerosol delivery were shown to be (i) maintaining the aerosol delivery flow rate below the tracheal flow rate (to minimize CPAP line loss) and (ii) concentrating the aerosol within the first portion of the inhalation waveform. An optimized design was shown to deliver approximately 37–60% of the nominal dose through the system and to the lungs with low intersubject variability (1050–2200 g infants) across two modes of device actuation (automated and manual) with room for further improvement. Ergonomic curvatures and streamlining of the prong geometries were also found to reduce work of breathing and flow resistance compared with a commercial alternative.Graphical

Artificial Neural Network For Predictive Modeling of Quinoline Insolubles in Pitch in A Steel Industry: Quality and Sustainability

Objective: The objective of the present work was the development of an intelligent system based on artificial neural networks, supervised and with batch learning, to predict the quinoline insoluble quality (IQ) parameter of tar, using a set of data from a steel industry. Theoretical Framework: Tar, derived from coal tar, is widely used in the production of anodes for the aluminum industry, and its quinoline insoluble (IQ) content is a crucial parameter, influenced by factors such as coal mixing, coking parameters and heat treatment. IQ forecasting is challenging due to the complexity of the processes involved. To address this question, artificial neural networks (ANNs) have been applied to predict the IQ of tar, taking advantage of its ability to handle complex, nonlinear systems. Method: In this study, a feedforward RNA model was used, trained with the Levenberg-Marquardt algorithm. The model has been configured with two hidden layers and the tansig activation function. The training was carried out with real data from polymerization reactors, including variables such as level, temperature, nitrogen rate, feed flow rate of the polymerizers and tar IQ. The network was configured with 2000 interactions and 20 neurons in the hidden layer, obtaining a training error (MSE) of 1x10-20. Results and Discussion: The analysis of the results revealed that temperature and nitrogen flow have the greatest influence on the IQ of the pitch, with higher temperatures and higher flow rates resulting in a higher IQ. Research Implications: ANN modeling is effective in predicting and optimizing industrial processes, especially in the analysis of large volumes of data and complex systems, contributing to quality control in pitch production and the improvement of industrial processes. Originality/Value: The main contribution of this work lies in the demonstration of the ability of artificial neural networks to accurately model the content of Quinoline Insolubles (IQ) of the pitch, even in the face of the significant dispersion observed in the input data. This finding is particularly relevant because the high variability of the data often poses a challenge for traditional predictive models. The precision achieved by the neural network, therefore, proves the feasibility and potential of this approach to overcome the limitations inherent to the complexity of the pitch production process and optimize its control, opening new perspectives for the steel industry

Parametric optimization of abrasive waterjet machining for aluminum 7075/boron carbide/zirconium silicate hybrid composites

In the present work, an attempt was made to study the machining characteristics of Hybrid Metal Matrix Composites (HMMCs) using Abrasive Waterjet Machining (AWJM). For preparing the composites, Aluminum alloy 7075 is cast with boron carbide (B4C) and zirconium silicate (ZrSiO4) reinforcement by the method of stir casting. Experimental investigation of the machining parameters on Depth of Cut (DoC), Material Removal Rate (MRR), and Surface Roughness (SR) was done. The independent parameters include Abrasive Mesh Size (AMS), Abrasive Flow Rate (AFR), Water Jet Pressure (WJP), and Traverse Rate (TR). The results of experiments reveal that low TRs increase SR, while short AMSs, high flow rates, and large WJPs increase DoC and MRR. Surface maps made by SEM exposed information about the surface texturing and the material removal processes. It was found that the optimal DoC was achieved at an AMS 80#, AMS of 340 g/min, WJP of 200 MPa, and TR of 60 mm/min for both unreinforced Al and the composite of Al + 5% B4C + 5% ZrSiO4. The results enable the development of proper AWJM procedures for HMMCs to ensure better surface finish and workability. From the experiments, it was observed that while smaller mesh sizes and greater AFR will improve MRR and DoC, it can at the same time have a negative effect on the overall performance of Kerf Taper angle (KT) and Surface Roughness (SR).

Renal pelvis pressure and flowrate with a multi-channel ureteroscope: invoking the concept of outflow resistance.

Understanding renal pelvis pressure (PRP) during ureteroscopy (URS) has become increasingly important. High irrigation rates, desirable to maintain visualization and limit thermal dose, can increase PRP. Use of a multi-channel ureteroscope (m-ureteroscope) with a dedicated drainage channel is one strategy that may facilitate simultaneous low PRP and high flowrate. We sought to define the relationship between PRP and flowrate across a range of different outflow resistance scenarios with an m-ureteroscope versus a single-channel ureteroscope (s-ureteroscope). The m- or s-ureteroscope was placed into the pelvis of a validated silicone kidney-ureter model. Trials were conducted at irrigation pressures (50-150 cmH20) and five different outflow resistance scenarios simulated with catheters of different lengths and diameters. PRP was measured with a fiber optic pressure sensor positioned in the renal pelvis. Flowrate was determined by measuring the mass of drainage fluid over 60s. PRP was lower with the m-ureteroscope than the s-ureteroscope when equivalent flowrates were delivered (i.e. 34 vs. 82 cmH20 respectively with 15ml/min irrigation in a high outflow resistance scenario). Flowrate was higher with the m-ureteroscope than the s-ureteroscope when equivalent irrigation pressures were applied (i.e. 28 vs. 14ml/min respectively with irrigation pressure 150 cmH20 in a high outflow resistance scenario). The m-ureteroscope has improved pressure-flow dynamics imparting important clinical benefits. More importantly, this approach to framing ureteroscopy in the context of pressure-flow relationships related by resistance values allows quantification of ureteroscopy within a deterministic system, which can be used to streamline future device development and technological innovation.

High-flow nasal cannula oxygen therapy versus non-invasive ventilation in healthy respiratory physicians: a non-randomized study.

High-flow nasal cannula (HFNC) and non-invasive ventilation (NIV) are commonly used for respiratory support. This study aims to first establish whether to use HFNC or NIV based on comfort levels, and subsequently evaluate diaphragmatic function under equivalent comfort levels to determine the optimal modality for clinical application. A self-controlled, non-randomized study was conducted with 10 healthy respiratory physicians as participants. Each subject was exposed to different HFNC settings, including flow rates of 20, 40, and 60 L/min at both 33 and 37°C. Additionally, participants were assessed under NIV mode. Comfort levels as the primary outcome were evaluated using the Visual Numerical Scale (VNS). Meanwhile, vital signs and diaphragmatic mobility were monitored through an electrocardiograph and ultrasound. HFNC at a flow rate of 20 L/min provided greater comfort than NIV. However, as the flow rate increased, this comfort benefit decreased. At 40 L/min, comfort levels were similar between HFNC and NIV, while at 60 L/min, HFNC was less comfortable than NIV. Notably, temperature variations between 33 and 37°C had no significant effect on comfort. In addition, under conditions of similar comfort, HFNC demonstrated slightly greater diaphragmatic mobility compared to NIV. Our study indicated HFNC was the preferred choice for providing respiratory support at low to moderate flow rates in healthy volunteers not requiring respiratory support. By contrast, at higher flow rates, NIV discomfort was lower than HFNC discomfort.

Bimetallic Nickel-Palladium Nanoparticles Supported on Multiwalled Carbon Nanotubes for Suzuki Cross-Coupling Reactions in Continuous Flow.

An efficient Suzuki cross-coupling reaction under continuous flow conditions was developed utilizing an immobilized solid supported catalyst consisting of bimetallic nickel-palladium nanoparticles (Ni-Pd/MWCNTs). In this process, the reactants can be continuously pumped into a catalyst bed at a high flow rate of 0.6 mL/min and the temperature of 130 °C while the Suzuki products are recovered in high steady-state yields for prolonged continuous processing. The catalyst was prepared by mechanical shaking of the appropriate nickel and palladium salts using ball-mill energy without the requirement of any solvent or reducing agent. This straightforward, facile, and simple method allows for bulk production of Ni-Pd/MWCNTs nanoparticles with a small particle size ideal for application in continuous flow cross-coupling catalysis. The as-prepared catalyst mostly contains nickel (7.9%) with a very small amount of palladium (0.81%) according to ICP-OES analysis. This remarkable immobilized catalyst can be used several times for different Suzuki reactions with a minimum loss of reactivity and no detectable leaching of the metal nanoparticles. Notably, by modifying the groups on both aryl halides and phenylboronic acids, the method provides access to a diverse array of the Suzuki products in flow with high steady-state yield, making it suitable for applications in industrial and pharmaceutical scales. Moreover, several spectroscopic techniques were employed to identify the structure and composition of the as-prepared Ni-Pd/MWCNTs nanoparticles before and after the reaction in flow such as transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), BET surface area (physisorption), and FTIR spectroscopy.

Implications of non-native metal substitution in carbonic anhydrase - engineered enzymes and models.

The enzyme carbonic anhydrase has been intensely studied over decades as a means to understand the role of zinc in hydrating CO2. The naturally occurring enzyme has also been immobilized on distinct heterogeneous platforms, which results in a different hybrid class of catalysts that are useful for the adsorption and hydration of CO2. However, the reusability and robustness of such natural and immobilized systems are substantially affected when tested under industrial conditions, such as high temperature and high flow rate. This led to the generation of model systems in the form of metal-coordination complexes, metal-organic frameworks, metallo-peptide self-assembled supramolecules and nanomaterials that mimic the primary, and, to some extent, secondary coordination sphere of the active site of the natural carbonic anhydrase enzymes. Furthermore, the effects of zinc-substitution by other relevant transition metals in both the naturally occurring enzymes and model systems has been reported. It has been observed that some other transition metal ions in the active site of carbonic anhydrase and its models can also accomplish similar activity, established by various reaction probes and ideas. Herein, we present a comprehensive highlight about substituting zinc in the active site of the modified enzymes and its biomimetic model systems with non-native metal ions and review how they affect the structural orientation and reactivity towards CO2 hydration. In addition, the utility of artificially engineered carbonic anhydrases towards a number of non-natural reactions is also discussed.

Instability mechanism and a fractal theory-based relative permeability model of immiscible two-phase displacement in rough fractures

The two-phase displacement in rock fractures is a critical scientific challenge in deep energy development projects, characterized by the intricate and dynamic flow patterns resulting from the complex fracture geometry and mutual interference between the two-phase fluids. The present study involves the construction of a three-dimensional rough fracture fine model using the fast Fourier transform and Gaussian distribution method. The phase field-finite element method is employed to simulate the dynamic displacement of water-oil flow and the evolution of the water-oil interface, aiming to investigate the impact of roughness, aperture, and wettability on the viscous fingering pattern observed in rough fractures. The numerical results indicate that the immiscible two-phase displacement presents a viscous fingering pattern at a high flow rate. Moreover, the greater the roughness is, the higher the number of fingering is, and the more volatile the change in displacement velocity is. The width of the wet-phase flow channel increases proportionally with the fracture aperture increasing. Furthermore, the morphology of immiscible two-phase interface within fractures is also influenced by the wetting angle, and the fingering, bifurcation, and crushing phenomena appear in the oil-wet state with the strong displacement interface instability. Finally, a fractal model of relative permeability for waterflooding in rough fractures is proposed based on the cubic law of flow and fractal dimension of aperture distribution, which has been validated through comparison with numerical results.

Methodology to compute the speed of pumps that fit the hydrodynamic levels in a well field

Pumping water from well fields is challenging for any water company, due to the restrictions attached to the aquifers’ hydrogeological characterisation. The difficulty is to set the speed of each pump allowing ensuring a quasi-uniform pumping from all wells in a field, at the highest flow rate that can be extracted from each well, paying attention to avoid clogging. In this paper we propose a methodology to compute the speed of each pump in a well field, corresponding to the desired pumped flow rate range, by keeping the requested hydrodynamic level in each well. The method is exemplified for a case study in Bucharest − a small well field, for which hydrogeological data are available. The nonlinear system of equations that defines the hydraulic system operation is solved in MATLAB for the stationary flow regime attained after reaching constant hydrodynamic levels in all wells. The numerical model of the well field is finally set and run in EPANET, within a dynamic analysis (simulation over an extended period of time), where water levels in the wells adjust to the extracted flow rate, according to the hydrogeological data. Two operating scenarios are discussed.

Flow control of blade-end oscillating jets on corner separation in a high-load compressor cascade

Based on unsteady numerical simulation, the feasibility of utilizing a fluid oscillator to generate oscillating jets for relieving the compressor cascade's corner separation was investigated. First, at design incidence angle, the optimal jet position is located where corner separation is not fully developed (74% axial chord length). Jets at more upstream and downstream positions are less effective due to premature dissipation of jet effects and the occurrence of high corner losses, respectively. The effectiveness of separation control through jet injection increases with higher jet mass flow rates, and the scheme with 0.66% relative jet flow rate exhibits a wide effective jet position range. However, excessively low jet flow rates are sensitive to jet position selection, while excessively high jet flow rates lead to significant mixing losses, resulting in high overall field losses and reduced engineering applicability. Second, the optimal jet scheme remains consistent at both design and high incidence angles and exhibits effective control at other off-design incidence angles. Finally, the oscillating jet suppresses the spanwise development of wall vortex and passage vortex within the blade passage by injecting high-momentum flow. Moreover, proper orthogonal decomposition analysis indicates that the oscillating jet redistributes the modal energy of the original flow field, exciting the vortex structures into high-frequency, small-scale oscillations at the jet frequency. Meanwhile, the oscillating jet primarily facilitates momentum exchange through strong mixing with passage vortex, wall vortex, and concentrated separation vortex, ultimately mitigating corner separation and reducing corner loss.

Delayed onset macular hemorrhage following previous intraocular tuberculosis

Aims/Purpose: Mycobacterium tuberculosis, an acid‐fast‐staining bacterium, thrives in oxygen‐rich environments due to its obligate aerobe nature. Consequently, tuberculous lesions often manifest in highly oxygenated tissues. Among these tissues, the choroid stands out for its exceptionally high blood flow rate, making it a prime site for M. tuberculosis colonization. We will focus on macular hemorrhages as a complication following intraocular tuberculosis, which may have a delayed onset and arise from inactive lesions.Methods: Presentation of a clinical case.Results: We present a case involving a 58‐year‐old patient who presented to the Emergency Room with complaints of acute loss of visual acuity in her right eye. She had been immunocompromised in the past, and had a personal history of intraocular tuberculosis, which she reported had been inactive for years. On examination, her visual acuity was measured at 0.1 in the affected eye. Fundus examination revealed a macular hemorrhage surrounding a choroidal scar. There were no signs of anterior ocular involvement, vitreal inflammation, or active choroiditis. The patient was otherwise asymptomatic. Despite the lack of active lesions, a chest radiograph was performed to rule out active tuberculosis in the lungs, yielding negative results. Active tuberculosis disease was hence ruled out, as well as the need for systemic anti‐TB therapy. The patient was started on antiVEGF intravitreal injections. The patient was scheduled for follow‐up visits, and her visual acuity had improved to 0.8 in the right eye after four months.Conclusions: Choroidal neovascularization and hemorrhages are rare complications of intraocular tuberculosis, and they may arise from both active and inactive lesions. Activity can be determined by fundus examination and fluorescein angiography. Any systemic symptoms should also be recorded on the patient's history. If risen from an inactive choroidal scar, a macular hemorrhage should be treated with anti VEGF injections.

Uncertainty analysis in river quality management considering failure probability: controllable and uncontrollable input pollutants.

River quality management involves complex challenges due to inherent uncertainties in various parameters, especially when dealing with controllable and uncontrollable pollutants. This study integrates a finite volume approach, called SEF (symmetric exponential function), with Monte Carlo simulations in MATLAB to solve the advection-dispersion equation, focusing on evaluating river quality protection tools by considering failure probability (Pf). Critical specifications for maintaining reliable river ecosystem performance are identified. We simulate assimilation capacity for managing river water quality against controllable pollutants to satisfy allowable pollution concentration at the high-reliability index. Using the Genetic Programming (GP) algorithm, a new accurate equation for assimilation capacity calculation is presented considering Pffor the first time. Results indicate that flow velocity significantly affects river assimilation capacity: increasing velocity can shift the river to a hazardous state while decreasing it allows for greater pollutant assimilation. Sustainable protection tools, including dilution flow and detention time, are considered to manage uncontrollable pollutants within a specific time (Tc) and river length constraints (Lc), safeguarding river water quality for both human and animal populations. Dilution flow is practical for specific base velocities but ineffective at high base flow rates. Conversely, detention time consistently protects water quality across all base flow velocities within the Lc constraint. Moreover, this study introduces the ratio of detention time to initial pollution contact duration as a vital water quality index to protect the rivers' environment. Combining numerical methods with reliability analysis and soft computing techniques, this research provides valuable insights into river system dynamics and protecting river water quality.