deposition patterns
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2021 ◽  
Vol 10 (1) ◽  
pp. 13
Author(s):  
Paran Pourteimouri ◽  
Geert H. P. Campmans ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher

The attractiveness of beaches to people has led, in many places, to the construction of buildings at the beach–dune interface. Buildings change the local airflow patterns which, in turn, alter the sediment transport pathways and magnitudes. This induces erosion and deposition patterns around the structures. In this study, a numerical model is developed using the open-source computational fluid dynamics solver OpenFOAM. First, the model is used to predict the airflow patterns around a single rectangular building. The model predictions are validated with wind-tunnel data, which show good agreements. Second, a reference beach building is introduced and then the building dimensions are increased in length, width and height, each up to three times the reference building dimension. The impact of each dimensional extent on the near-surface airflow patterns is investigated. The results show that the near-surface airflow patterns are least dependent on the length of the building in the wind direction and they depend most on the width of the building perpendicular to the wind direction. Third, the convergence of the third-order horizontal near-surface velocity field is calculated to interpret the impact of changes in airflow patterns on potential erosion and deposition patterns around the building. The numerical predictions are compared with the observed erosion and sedimentation patterns around scale models in the field. The comparisons show satisfactory agreements between numerical results and field measurements.


2021 ◽  
Author(s):  
Shawn Angelo Zamperini ◽  
J.H. Nichols ◽  
Peter C. Stangeby ◽  
David Donovan ◽  
Jonah David Duran ◽  
...  

Abstract Near-separatrix impurity accumulation between the crown and the outer midplane of tokamaks is a common feature in results from codes such as SOLPS-ITER and DIVIMP; however, experimental evidence of accumulation has only recently been obtained and is reported here. The codes find that the poloidal distribution of impurity ions in the scrape-off layer (SOL) depends primarily on toroidal field (BT)-dependent parallel flow patterns of the background plasma and the parallel ion temperature gradient (∇||Tion) force. Experimentally, Mach probes used in L-mode plasmas with favorable (for H-mode access) BT measure fast (M~0.3-0.5) inner-target-directed (ITD) background plasma flows at the crown of single-null discharges. This study reports a set of DIVIMP simulations for two similar H-mode discharges from the DIII-D W Metal Rings Campaign differing primarily in BT-direction to assess the effect that fast ITD flows have on the distribution of W ions in the SOL. It is found that for imposed ITD flows of M = 0.3, W ions that otherwise accumulate due to the ∇||Tion-force are largely flushed out. It is also found that doubling the radial diffusion coefficient from 0.3 to 0.6 m2/s prevents accumulation due to rapid cross-field transport into the far-SOL, where background plasma flows drain W ions to the divertors. Far-SOL W distributions from DIVIMP are then used to specify input to the impurity transport code 3DLIM, which is used to interpretively model collector probe deposition patterns measured in the “wall-SOL.” It is demonstrated that the deposition patterns are consistent with the DIVIMP predictions of near-SOL accumulation for the unfavorable-BT direction, and little/no accumulation for the favorable-BT direction. The wall-SOL collector probes have thus provided the first experimental evidence, albeit indirect, of near-SOL W accumulation – finding it occurs for the unfavorable-BT direction only. For the favorable-BT direction, fast flows can largely prevent accumulation from occurring.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Omar Usmani ◽  
Nicolas Roche ◽  
Ezanul Wahab ◽  
Samuel Israel ◽  
Martin Jenkins ◽  
...  

Abstract Background Triple therapy with inhaled corticosteroids/long-acting muscarinic antagonists/long-acting β2-agonists (ICS/LAMA/LABA) is recommended for patients with chronic obstructive pulmonary disease (COPD) with continued symptoms or exacerbations, despite treatment with LAMA/LABA or ICS/LABA. The pulmonary, extrathoracic, and regional lung deposition patterns of a radiolabeled ICS/LAMA/LABA triple fixed-dose combination budesonide/glycopyrrolate/formoterol fumarate (BGF 320/18/9.6 μg), delivered via a single Aerosphere metered dose inhaler (MDI) were previously assessed in healthy volunteers and showed good deposition to the central and peripheral airways (whole lung deposition: 37.7%). Here, we report the findings assessing BGF in patients with moderate-to-very severe COPD. Methods This phase I, single-dose, open-label gamma scintigraphy imaging study (NCT03906045) was conducted in patients with moderate-to-very severe COPD. Patients received two actuations of BGF MDI (160/9/4.8 μg per actuation) radiolabeled with technetium‑99‑pertechnetate, not exceeding 5 MBq per actuation. Immediately following each inhalation, patients performed a breath-hold of up to 10 s, then exhaled into an exhalation filter. Gamma scintigraphy imaging of the anterior and posterior views of the lungs and stomach, and a lateral head and neck view, were performed immediately after exhalation. The primary objective of the study was to assess the pulmonary deposition of BGF. Secondary objectives assessed the deposited dose of radiolabeled BGF in the oropharyngeal and stomach regions, on the actuator, and on the exhalation filter in addition to regional airway deposition patterns in the lungs. Results The mean BGF emitted dose deposited in the lungs was 32.1% (standard deviation [SD] 15.6) in patients with moderate-to-very severe COPD, 35.2% (SD 12.8) in patients with moderate COPD, and 28.7% (SD 18.4) in patients with severe/very severe COPD. Overall, the mean normalized outer/inner ratio was 0.55 (SD 0.19), while the standardized central/peripheral ratio was 2.21 (SD 1.64). Conclusions Radiolabeled BGF 320/18/9.6 μg was efficiently delivered and deposited throughout the entire lung, including large and small airways, in patients with moderate-to-very severe COPD, with similar deposition in patients with moderate COPD and patients with severe/very severe COPD. Trial registration: ClinicalTrials.gov, NCT03906045. Registered 8 April 2019, https://clinicaltrials.gov/ct2/show/NCT03906045


Author(s):  
Yaser Qureshi

While some heavy metals are essential trace components, many are bio toxic in human biochemistry. As a result, a full grasp of underlying systems is required. For supporting life and minimizing environmental damage, we must grasp their sources, liquidation techniques, chemical modifications, and deposition patterns These metals are discharged into the environment by both natural and human activity, including mining, industrial operations, and vehicular emissions. Soils and groundwater are contaminated when they leak into subsurface fluids and eventually into the aquifer. The world's commerce and coordinating systems frequently generate environmental toxicity and poisoning. Swallowed, they generate bio toxic compounds, lose structural integrity, and block bio reactions. This study's goal is to learn more about heavy metals and their bio toxic effects on humans.


2021 ◽  
pp. 110122
Author(s):  
Markus Köhler ◽  
Li Sun ◽  
Jonas Hensel ◽  
Sakari Pallaspuro ◽  
Jukka Kömi ◽  
...  

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