ABSTRACT This study employs field monitoring, hydrochemical analysis, lab experiments, and tracer tests to characterize multilevel groundwater flow systems and circulation patterns in karst aquifers, establishing a classification framework for spring protection. The main findings are as follows: (1) The Jinan area comprises two first-order karst water systems, specifically the Jinan Monocline Karst Water System and the Laiwu Basin Karst Water System. The Jinan Monocline system is further subdivided into five second-order intermediate flow systems. (2) The multilevel karst water circulation patterns are primarily classified into three major categories. The unconfined local flow system includes three circulation patterns. The confined intermediate flow system comprises three patterns, with the window-type intermediate system further divided into three subtypes. (3) The local flow system performs water conservation functions, serving as an indirect recharge source for the four major spring groups. The intermediate flow system constitutes the primary direct recharge source, mandating rigorous protection of the Cambrian-Ordovician karst aquifer in its recharge area. The confined regional system with deep circulation must adhere to the ‘heat extraction without water withdrawal’ development principle, preventing geothermal development activities from impacting the sustainable discharge of the spring clusters.

Based on a decade of observational and reanalysis data, this study systematically analyzes the main atmospheric circulation patterns and environmental conditions linked to warm-season short-duration heavy precipitation in the Western Tianshan Mountains, Xinjiang. Three dominant circulation patterns are identified: the Low-Trough pattern, the Low-Vortex pattern, and the Eastward-moving Waves pattern. The Low-Trough and Low-Vortex patterns are further divided into subtypes based on the location of the trough or vortex, while the Eastward-moving Waves pattern is characterized by a zonal flow with eastward-moving short-wave disturbances. Short-duration heavy precipitation shows a clear daily cycle across all patterns, with the highest frequency occurring from afternoon to early evening. Rainfall tends to concentrate on windward slopes and in valleys. The exact location of precipitation is influenced by the pressure gradient and wind direction—shifting northward under stronger westerly winds and southward under weaker southwesterly flows. The Low-Vortex pattern exhibits the strongest coupling between upper- and low-level jets and the most extensive jet coverage, providing optimal lifting conditions for intense and widespread rainfall. The Low-Trough pattern shows moderate jet coupling, while the Eastward-moving Waves pattern relies on weak upper-level forcing, resulting in more limited precipitation. Moderate vertical wind shear is common during these events. All patterns display a consistent vertical structure of pseudo-equivalent potential temperature, characterized by a “high–low–high” pattern. The Low-Vortex pattern features a prominent upper-level high-value layer and a shallow mid-level cool layer, favoring intense convection. The Low-Trough pattern shows strong heating in both the upper and lower levels but a more distinct mid-level cool zone, enhancing atmospheric instability. In contrast, the Eastward-moving Waves pattern has a thick mid-level cool layer and weak low-level heating, leading to the weakest convective potential. The Low-Vortex and Low-Trough patterns are associated with higher low-level moisture, while the drier Eastward-moving Waves pattern requires greater convective available potential energy and lower convective inhibition to initiate convection.

Abstract This study uses the airborne Doppler radar data set, TC‐RADAR, and model simulations from the Penn State Ensemble Kalman Filter data assimilation system to examine the dynamics and evolution of tropical cyclone (TC) rainband convective updrafts. This examination utilizes an updraft selection algorithm and statistical analysis of convective updraft characteristics previously developed based on observations of TC rainband convective updrafts. The selected updrafts are collectively analyzed by their spatial frequency, radius, azimuthal location (relative to the environmental 200–850 hPa wind shear and environmental 850 hPa mean flow), structural characteristics, and secondary circulation (radial/vertical) flow pattern. The observed updrafts compare favorably with the simulated updrafts. A wavenumber‐1 asymmetry is found, showing that convective updrafts in the downshear quadrants of the TC are more frequent. The radial flow of updraft circulations aligns with the prevailing vortex‐scale radial flow, which is governed by the environmental shear or low‐level mean flow‐induced asymmetry. Convective‐scale circulations are hypothesized to be significantly influenced by vortex‐scale radial flow at the updraft base and top altitudes. The bottom‐up decay of aging convective updrafts, caused by increased low‐level downdrafts, affects the base altitude and the subsequent radial flow of the updraft circulation. The findings presented in this study support previous literature regarding observed convective‐scale patterns of organized rainband convection in a mature TC.

This study employs computational fluid dynamics to investigate fuel mixing behavior behind a strut equipped with a diamond injector in a supersonic combustion chamber. Three distinct diamond injector configurations are analyzed in a three-dimensional model of the strut under a free-stream Mach number of 2.2. The hydrogen distribution and flow structures associated with these configurations are comprehensively examined to identify the most effective mechanism for fuel mixing within the combustor. Additionally, the circulation strength and flow patterns are evaluated to compare the flow variations influenced by the injector shapes. The numerical simulation results indicate that the diamond injector with an expansive distribution achieves a higher efficiency in fuel mixing, despite exhibiting a lower circulation strength. The findings reveal that circulation formation within the jet core significantly enhances fuel mixing compared to the side vortices.

Teuku Umar Barat – Gunung Salak Street Intersection is one of the intersections that serves high traffic movement in the West Denpasar area. The problems that occur at the intersection are traffic congestion with high delays, especially during rush hours. To improve the performance of the intersection so that efficiency and smooth traffic flow can be achieved, a study was conducted with the aim of regulating traffic management in the intersection area with a one-way flow circulation pattern. Analysis of the performance of the section and intersection in existing conditions and the planned scenario using MKJI 1997, there are two alternative traffic managements, namely Alternative 1: Diverting Traffic Movement on the North and South Legs (North Gunung Salak Street – South Gunung Salak Street) multi-program traffic signal arrangements. Alternative 2: Diverting Traffic Movement on the East and South Legs (West Teuku Umar Street – South Gunung Salak Street) with traffic signal arrangements. The results of the analysis show that Alternative 2 is the best solution to reduce the amount of delays and increase the capacity and level of service at the Teuku Umar Barat – Jalan Gunung Salak intersection.

Schistosomiasis, a debilitating parasitic disease of poverty affecting more than 250 million people worldwide, is contracted upon contact with the larval form of the parasite, known as cercaria, emerging from infected freshwater snails, the obligate intermediate host of the parasite. Understanding how infectious larvae can be transported in rivers and irrigation canals is crucial to fine-tune environmental interventions targeting the parasite and its intermediate host. Specifically, lateral cavities along many tropical rivers act as water access points but can also entrap parasitic larvae and provide low-velocity environments for snail-supporting vegetation to flourish, creating potential areas of high schistosomiasis infection. In this paper, the circulation of larvae in a typical transmission site along the Lampsar River in Senegal is modeled under a range of wind and vegetation conditions to better understand how such environmental factors affect their transport. We found that wind direction has a large influence on the distribution and abundance of parasitic larvae at the water access point, whereas increasing wind speed scales velocities but does not affect flow patterns. The area of coverage of vegetation can significantly alter flow magnitudes and circulation patterns for the same wind speed and direction. Increasing vegetation coverage generally leads to an increase in larvae residence time in the side pond, but the relationship is non-monotonic with five regimes of residence time behavior based on vegetation patch radius. The results suggest that there is an optimal patch radius at which larvae residence time and velocity deviations within the side pond are maximized.

The geometric configuration, particularly the inner tube diameter, plays a significant role in the thermal performance of pulsating heat pipes (PHPs). Previous experimental research has demonstrated that single-loop triple-diameter PHPs (TD-PHPs) outperform single-loop single-diameter PHPs (SD-PHPs) and dual-diameter PHPs (DD-PHPs) in terms of thermal performance under moderate heating input powers ranging from 25 W to 75 W. However, a reduction in heat input from 75 W to 25 W leads to a diminished impact of TD-PHPs on the thermal performance. Therefore, to improve the overall performance of TD-PHPs, this study used two-dimensional transient computational fluid dynamics simulations to identify the optimal inner tube diameters for TD-PHPs at a low heat input by evaluating the thermal resistance of five TD-PHPs with various inner diameters. The findings reveal that the TD-PHP configuration exhibits minimum thermal resistance, with inner diameters of 4.5 mm for the upper arch (the condenser section), 4.0 mm for the wide branch, and 2.5 mm for the narrow branch, primarily due to its full circulation flow pattern. Furthermore, the overall heat transfer performance of the optimal TD-PHP was compared with that of an SD-PHP at low heat inputs (10 and 18 W), indicating that although the optimal TD-PHP shows lower thermal resistance, it does not significantly affect the start-up time.

The details of the interaction of human thermal plume and breathing activities are simulated in the current study of an unsteady turbulent flow field in an elevator cabin. Air velocity and temperature distributions of the circulation flow pattern (i.e., the macroenvironment), the breathing‐scale microenvironment’s characteristics, and the thermal plume’s fate are analyzed. The current study is aimed at showing how respiratory activities such as breathing and human thermal plumes affect the flow field and respiratory contaminants dispersion pattern in a nonventilated enclosed environment (the elevator cabin). The results from three cases, i.e., breathing thermal manikins, nonbreathing thermal manikins, and isothermal breathing manikins, are contrasted to unveil better the effects of human thermal plume and breathing on the flow field, including the velocity distribution, dispersion pattern of the exhaled contaminant, the human body’s heat transfer coefficient, and the large‐scale flow pattern. Results reveal that breathing inhalation increases the upward velocity of the thermal plume on the one hand, which directly affects the microenvironment and indirectly impacts the macroenvironment due to the more vigorous reflected thermal plume. On the other hand, the upward thermal plume reduces the penetration length of the exhaled jet. Breathing activities create ring vortices that connect the microenvironment and the macroenvironment. The circulation flow features a downward flow in the cabin’s center, affecting the vortex strength and contaminant dispersion pattern. Overall, the human thermal plume and human breathing make comparable contributions to the resulting elevator‐cabin flow characteristics.

Numerical evaluation of respiratory droplet removal by an ionic wind-driven electrostatic device in an indoor environment

Experimental investigation of three-dimensional gas-solid flow in CFB cyclone separator using electrical capacitance volume tomography

Abstract We conducted analogue experiments to examine flux‐driven and buoyancy‐driven magma ascent, which included a series of isothermal experiments and thermal, solidification‐prone experiments. We measured the internal flow using 2D particle image velocimetry, which indicates that buoyancy has a strong control on the flow pattern of isothermal dikes. Dikes that are not buoyant (likely driven by source pressure) take on a circulating pattern, while buoyant dikes assume an ascending flow pattern. Solidification modifies the flow field so that flow is confined to the dike's upper head region. The lower tail becomes mostly solidified, with a narrow conduit connecting the source to the head. We interpret that this conduit acts as a high velocity point source to the head, promoting a circulating flow pattern, even as the dike becomes buoyant. We then perform particle tracking velocimetry on several particles to illustrate the complexity of their paths. In a circulating flow pattern, particles rise to the top of the dike, descend near the lateral edge, and then are drawn back into the upward flow. In an ascending pattern, particles ascend slightly faster than the propagation velocity, and therefore are pushed to the side as they approach the upper tip. In erupting dikes, particles simply flow to the vent. In the context of crystal growth in magmatic dikes, these results suggest that crystal growth patterns (e.g., normal or oscillatory zoning) can reflect the magma flow pattern, and potentially the driving forces.

With the increasingly severe situation of water pollution control, optimal design of the mixing flow field of submersible mixers and improving the mixing uniformity of activated sludge have become key research issues. At present, the research on the submersible mixer is mostly focused on water as the medium, and the flow field characteristics of solid-liquid two-phase flow, which is closer to the actual scene, still need more systematic research. This paper presented numerical simulations of the solid‒liquid two‒phase flow problem at various installation heights based on the coupled CFD‒DEM method in the Euler‒Lagrange framework. The velocity distribution, dead zone distribution, particles’ velocity development, particles’ mixing degree, and particles’ aggregation of the flow field were compared and analyzed for different installation heights. The results show that the flow field has two flow patterns: single‒ and double‒circulation, due to different installation heights, in which the velocity and turbulent kinetic energy of the flow field of the double‒circulation flow pattern are more uniform. The installation height affects the moment particles enter the impeller and the core jet zone, thus affecting the degree of particle mixing and the mixing time. The adjustment of the installation height also has an impact on particle aggregation. These findings indicate that the installation height significantly affects the flow field characteristics and the particle motion distribution. The coupled CFD‒DEM method can analyze the macroscopic phenomenon of the solid‒liquid two‒phase flow field of the submersible mixer from the scale of microscopic particles, which provides a theoretical approach for the optimal design of the mixing flow field. It can provide better guidance for engineering practice.

Abstract Ten years of airborne Doppler radar observations are used to study convective updrafts' kinematic and reflectivity structures in tropical cyclone (TC) rainbands. An automated algorithm is developed to identify the strongest rainband updrafts across 12 hurricane‐strength TCs. The selected updrafts are then collectively analyzed by their frequency, radius, azimuthal location (relative to the 200–850 hPa environmental wind shear), structural characteristics, and secondary circulation (radial/vertical) flow pattern. Rainband updrafts become deeper and stronger with increasing radius. A wavenumber‐1 asymmetry arises, showing that in the downshear (upshear) quadrants of the TC, updrafts are more (less) frequent and deeper (shallower). In the downshear quadrants, updrafts primarily have in‐up‐out or in‐up‐in secondary circulation patterns. The in‐up‐out circulation is the most frequent pattern and has the deepest updraft and reflectivity tower. Upshear, the updrafts generally have out‐up‐in or in‐up‐in patterns. The radial flow of the updraft circulations largely follows the vortex‐scale radial flow shear‐induced asymmetry, being increased low‐level inflow (outflow) and midlevel outflow (inflow) in the downshear (upshear) quadrants. It is hypothesized that the convective‐scale circulations are significantly influenced by the vortex‐scale radial flow at the updraft base and top altitudes. Other processes of the convective life cycle, such as bottom‐up decay of aging convective updrafts due to increased low‐level downdrafts, can influence the base altitude and, thus, the base radial flow of the updraft circulation. The findings presented in this study support previous literature regarding convective‐scale patterns of organized rainband convection in a mature, sheared TC.

Abstract Qualitative and quantitative studies of laminar mixing in a corotating disk processor chamber were carried out experimentally and theoretically. Theoretical study of the flow field in a parallel chamber indicates the presence of an orthogonal circulation flow pattern with a double circulation pattern at constant radii. A color tracer was used for studying experimentally the laminar mixing. The experiments verified the theoretically predicted flow fields and showed that the two orthogonal flow patterns bring about a composition randomization throughout the volume. Quantitative measurement of interfacial area evolution helped in characterizing the laminar mixing behaviour of such a configuration.

The most critical problems of electronic components are the high power consumption and lesser life. This paper aims to numerically model the working process of the water-cooled heat sink to obtain the most effective design. In this context, four types of configurations with different passes (Type-A, Type-B, Type-C, Type-D) were designed at different water velocities, which were 0.25 m/s, 0.5 m/s, and 1 m/s with constant air velocity (6 m/s) to simulate fluid flow and the heat transfer. Results were evaluated as temperature and pressure contours, velocity streamlines, and the graphics of pressure difference, outlet temperature, temperature difference, heat transfer rate to air, and power consumption in relation to Reynolds number. Results showed that pressure difference, outlet temperature, power consumption, and heat transfer rate to air increased by increasing Reynolds number in all analyses. In all configurations, the water outlet temperatures were very close to each other, in the range of 63-65 °C for Re=2500, 70-72 °C for Re=5000, and 74-76 °C for Re=10000. Among all configurations, Type-A has the minimum outlet temperature with the value of 63.40 °C for Re=2500, 70.77 °C for Re=5000, and 74.85 °C for Re=10000. Also, Type-A showed better performance than other models in terms of heat transfer rate to air with the value of 1346 W for Re=2500, 1500 W for Re=5000, and 1675 W for Re=10000. The maximum pressure difference was obtained in Type-A geometry with the value of nearly 3500 Pa at a Reynolds number value of 10000. When the results were evaluated in full scope, it was concluded that Type-B was the most suitable model for use in terms of heat transfer, pump power, and inlet-outlet positions.

The aluminum line overetched defect might be called as undercut PR Hole, etc by different manufacturers. The defect of this case study mainly shows a hole found on the aluminum line after stripper process but there is no any tracable symptom before the ending of dry etch process. That is, it seems no means to prevent or to found the root cause. A defect defense approach via cleanroom air quality database based integrated with TFT manufacturing processes air sampling characteristics of manufacturing chemicals cleanroom circulation and air flow pattern is proposed to demostrate how to figure out the root cause of aluminum line overetched defect, which found after stripper. Via the aid of proposed approach, the analysis shows the defect arises from the cross contamination between photo PVD and stripper process and the cross contamination comes from manufacturing layout cleanroom circulation and air flow pattern.

Abstract Background Atrial fibrillation (AF) is commonly encountered in patients with Hypertrophic Cardiomyopathy (HCM). Presence of AF in this high risk population is detrimental due to its effect on hemodynamics, diastolic function and potential induction of ventricular tachyarrhythmias. For these reasons a rhythm control strategy is highly desirable, and yet catheter ablation of AF is consistently inefficacious with poorer overall outcomes. We hypothesize that in HCM presence of outflow tract obstruction by virtue of its effect on left atrial hemodynamics, altered circulatory flow patterns in the pulmonary veins, and stretch related triggered activities would create an arrhythmogenic substrate, and have significant impact on the outcomes of catheter ablation of AF. In this study, we aimed to evaluate AF ablation outcomes based on the presence or absence of outflow tract obstructions in patients with HCM. Methods We conducted a retrospective study using the AHRQ-HCUP National Readmission Database for the years 2016–17. All adults (≥18 years) with HCM undergoing AF ablation procedures were identified using ICD-9 codes. The cohort was divided into two groups; Obstructive HCM (Group A) and Non-Obstructive HCM (Group B) Multivariate regression analysis was utilized to adjust for confounders. Independent risk factors for in-hospital mortality were identified using a proportional hazards model. Complications were defined as per the Agency for Health Care Research and Quality guideline. Results From a total of 71,451,419 patients in the NRD registry, 97 patients with HCM were identified and formed the study cohort. When divided based on the presence or absence of outflow tract obstruction, there were 25 patients with Obstructive HCM and 72 patients with Non-obstructive HCM. Both groups were similar in clinical characteristics including CHADVASc scores and Charlson Comobidity indices as outlined in Table 1. Procedural outcome analysis revealed higher 30-day cardiac readmissions in the Obstructive HCM group compared to Non-obstructive HCM (25.2% vs 7.97%, p=0.049). The Obstructive HCM group had higher rates of atrial arrhythmias, 57.97%, compared to 32.44% in the non-obstructive HCM group, and heart failure exacerbations, 41.27% vs 25.82%. However, both indices did not reach statistical significance. The procedural complications rates tended to be higher in the non-obstructive HCM group, 10.8% vs. 5.6% in the Obstructive HCM group (p=0.54). Conclusions Presence of an obstructive component to HCM is associated with significantly increased short term cardiac readmissions predominantly driven by recurrent atrial arrhythmias and heart failure. These findings suggest negative influence of altered cardiac hemodynamics related to outflow tract obstruction on atrial arrhythmias. The arrhythmogenic substrate of HCM may therefore be different and less amenable to catheter ablation. HCM ablation outcomes Funding Acknowledgement Type of funding source: None

In a companion paper, the U.S. Nuclear Regulatory Commission (NRC) staff has described analyses performed using the TRAC/RELAP Advanced Computational Engine (TRACE) code to study the transient system response of the NuScale power module to a postulated beyond-design-basis loss of alternating-current (LOAC) power transient where the module protection system completely fails to insert the control rods. The subject paper studies the sensitivity of the event progression and consequences to variation in the initial reactor coolant system (RCS) temperature. These studies were performed by varying the effective steam generator heat transfer surface area between 100% and 50% of the nominal area. The results of the NRC staff analyses show that at increased initial temperatures, it is possible for the NuScale primary side to remain critical for an extended period of time, leading to a sustained loss of primary-side inventory through pressure relief until the natural circulation flow pattern in the RCS becomes broken. After the flow loop is broken, reactor power decreases significantly, and the primary figures of merit important to safety are met with substantial margin.

The aluminum line overetched defect might be called as undercut、PR Hole, etc by different manufacturers. The defect of this case study mainly shows a hole found on the aluminum line after stripper process but there is no any tracable symptom before the ending of dry etch process. That is, it seems no means to prevent or to found the root cause. A defect defense approach via cleanroom air quality database based integrated with TFT manufacturing processes、air sampling、characteristics of manufacturing chemicals、cleanroom circulation and air flow pattern is proposed to demostrate how to figure out the root cause of aluminum line overetched defect, which found after stripper. Via the aid of proposed approach, the analysis shows the defect arises from the cross contamination between photo、PVD and stripper process and the cross contamination comes from manufacturing layout、cleanroom circulation and air flow pattern.

Confluences are nodes in riverine networks characterized by complex three-dimensional changes in flow hydrodynamics and riverbed morphology, and are valued for important ecological functions. This physical complexity is often investigated within the water column or riverbed, while few studies have focused on hyporheic fluxes, which is the mixing of surface water and groundwater across the riverbed. This study aims to understand how hyporheic flux across the riverbed is organized by confluence physical drivers. Field investigations were carried out at a low gradient, headwater confluence between Baltimore Brook and Cold Brook in Marcellus, New York, USA. The study measured channel bathymetry, hydraulic permeability, and vertical temperature profiles, as indicators of the hyporheic exchange due to temperature gradients. Confluence geometry, hydrodynamics, and morphodynamics were found to significantly affect hyporheic exchange rate and patterns. Local scale bed morphology, such as the confluence scour hole and minor topographic irregularities, influenced the distribution of bed pressure head and the related patterns of downwelling/upwelling. Furthermore, classical back-to-back bend planform and the related secondary circulation probably affected hyporheic exchange patterns around the confluence shear layer. Finally, even variations in the hydrological conditions played a role on hyporheic fluxes modifying confluence planform, and, in turn, flow circulation patterns.