Experimental Studies of Sedimentation Basin Dynamics

1977 ◽  
Vol 12 (1) ◽  
pp. 77-90
Author(s):  
J.F. Cordoba-Molina ◽  
P.L. Silveston ◽  
R. R. Hudgins
Keyword(s):  
Dynamic Response ◽  
Froude Number ◽  
Flow Model ◽  
Experimental Studies ◽  
Densimetric Froude Number ◽  
Number Range ◽  
The Real ◽  
Highly Correlated ◽  
Sedimentation Basins ◽  
Simple Flow

Abstract A simple Flow Model is proposed to describe the dynamic response of sedimentation basins. The response predicted by this model is linear as opposed to the real response of the basin which is nonlinear. However, the real response of the basin is highly correlated with its densimetric Froude number, and as a consequence our linear model effectively predicts the response of the basin in a restricted densimetric Froude Number range. Our experiments show that the response of the basin becomes more sluggish and erratic as the densimetric Froude number decreases.

scholarly journals Experimental studies on scour of supercritical flow jets in upstream of screens and modelling scouring dimensions using artificial intelligence to combine multiple models (AIMM)

2019 ◽  
Vol 21 (5) ◽  
pp. 893-907 ◽  
Author(s):  
Sina Sadeghfam ◽  
Rasoul Daneshfaraz ◽  
Rahman Khatibi ◽  
Omar Minaei
Keyword(s):  
Artificial Intelligence ◽  
Froude Number ◽  
Experimental Studies ◽  
Support Vector ◽  
Densimetric Froude Number ◽  
Number Range ◽  
Artificial Intelligence Models ◽  
Level 1 ◽  
Supercritical Flows ◽  
Level 2

Abstract Performances of screens in watercourses are investigated for dissipating energy of supercritical flows, capable of inducing scour or stabilising hydraulic jumps. Subsequent scouring pits are characterised by pit depth and pit length. Inherent processes are studied through laboratory tests by producing a set of empirical data to formulate a model of the scour for explaining subsequent processes. The experimental set-up comprises: (i) Froude number of supercritical flows (range: 3.5–8.0); (ii) particle densimetric Froude number (range: 2–10) using five granular samples; and (iii) two screen porosities (40% and 50%). Trained and tested artificial intelligence models explain the data by expressing depth and length of the pit through the following levels: Level 1: use the experimental data and test the models of: Sugeno fuzzy logic (SFL) and neuro-fuzzy (NF); and Level 2: use outputs of Level 1 models as inputs to support vector machine (SVM). The results reveal that the Level 2 model improves model performances compared with the single models with respect to R2, root mean square error (RMSE), Nash–Sutcliffe coefficient (NSC) and residual errors. While Level 1 models remain fit-for-purpose, the comparative improvement from Level 1 to Level 2 can be as high as 58% in terms of NSC for the testing phase.

scholarly journals PacBio full-length transcriptome of wild apple (Malus sieversii) provides insights into canker disease dynamic response

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaojie Liu ◽  
Xiaoshuang Li ◽  
Xuejing Wen ◽  
Yan Zhang ◽  
Yu Ding ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Early Response ◽  
Full Length ◽  
Differentially Expressed ◽  
Late Response ◽  
Response Mechanism ◽  
Necrotrophic Pathogen ◽  
Canker Disease ◽  
Malus Sieversii ◽  
Highly Correlated

Abstract Background Valsa canker is a serious disease in the stem of Malus sieversii, caused by Valsa mali. However, little is known about the global response mechanism in M. sieversii to V. mali infection. Results Phytohormone jasmonic acid (JA) and salicylic acid (SA) profiles and transcriptome analysis were used to elaborate on the dynamic response mechanism. We determined that the JA was initially produced to respond to the necrotrophic pathogen V. mali infection at the early response stage, then get synergistically transduced with SA to respond at the late response stage. Furthermore, we adopted Pacific Biosciences (PacBio) full-length sequencing to identify differentially expressed transcripts (DETs) during the canker response stage. We obtained 52,538 full-length transcripts, of which 8139 were DETs. Total 1336 lncRNAs, 23,737 alternative polyadenylation (APA) sites and 3780 putative transcription factors (TFs) were identified. Additionally, functional annotation analysis of DETs indicated that the wild apple response to the infection of V. mali involves plant-pathogen interaction, plant hormone signal transduction, flavonoid biosynthesis, and phenylpropanoid biosynthesis. The co-expression network of the differentially expressed TFs revealed 264 candidate TF transcripts. Among these candidates, the WRKY family was the most abundant. The MsWRKY7 and MsWRKY33 were highly correlated at the early response stage, and MsWRKY6, MsWRKY7, MsWRKY19, MsWRKY33, MsWRKY40, MsWRKY45, MsWRKY51, MsWRKY61, MsWRKY75 were highly correlated at the late stage. Conclusions The full-length transcriptomic analysis revealed a series of immune responsive events in M. sieversii in response to V. mali infection. The phytohormone signal pathway regulatory played an important role in the response stage. Additionally, the enriched disease resistance pathways and differentially expressed TFs dynamics collectively contributed to the immune response. This study provides valuable insights into a dynamic response in M. sieversii upon the necrotrophic pathogen V. mali infection, facilitates understanding of response mechanisms to canker disease for apple, and provides supports in the identification of potential resistance genes in M. sieversii.

scholarly journals Characterization of pendrin in urinary extracellular vesicles in a rat model of aldosterone excess and in human primary aldosteronism

2021 ◽  
Author(s):  
Fumika Ochiai-Homma ◽  
Emiko Kuribayashi-Okuma ◽  
Yuya Tsurutani ◽  
Kenichi Ishizawa ◽  
Wataru Fujii ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Rat Model ◽  
Primary Aldosteronism ◽  
Experimental Studies ◽  
Concomitant Administration ◽  
Therapeutic Interventions ◽  
Cross Sectional ◽  
Quantitative Changes ◽  
Highly Correlated ◽  
Sectional Analysis

AbstractPendrin is a Cl−/HCO3− exchanger selectively present in the intercalated cells of the kidney. Although experimental studies have demonstrated that pendrin regulates blood pressure downstream of the renin-angiotensin-aldosterone system, its role in human hypertension remains unclear. Here, we analyzed the quantitative changes in pendrin in urinary extracellular vesicles (uEVs) isolated from a total of 30 patients with primary aldosteronism (PA) and from a rat model of aldosterone excess. Western blot analysis revealed that pendrin is present in dimeric and monomeric forms in uEVs in humans and rats. In a rodent model that received continuous infusion of aldosterone with or without concomitant administration of the selective mineralocorticoid receptor (MR) antagonist esaxerenone, pendrin levels in uEVs, as well as those of epithelial Na+ channel (ENaC) and Na-Cl-cotransporter (NCC), were highly correlated with renal abundance. In patients with PA, pendrin levels in uEVs were reduced by 49% from baseline by adrenalectomy or pharmacological MR blockade. Correlation analysis revealed that the magnitude of pendrin reduction after treatment significantly correlated with the baseline aldosterone-renin ratio (ARR). Finally, a cross-sectional analysis of patients with PA confirmed a significant correlation between the ARR and pendrin levels in uEVs. These data are consistent with experimental studies showing the role of pendrin in aldosterone excess and suggest that pendrin abundance is attenuated by therapeutic interventions in human PA. Our study also indicates that pendrin analysis in uEVs, along with other proteins, can be useful to understand the pathophysiology of hypertensive disorders.

Vibrations of Foundations Interacting With Subsoil Experimental Studies and BE Calculations

1991 ◽  
Author(s):  
L. Gaul
Keyword(s):  
Boundary Element Method ◽  
Dynamic Response ◽  
Surface Waves ◽  
Boundary Element ◽  
Constitutive Equations ◽  
Experimental Studies ◽  
Boundary Elements ◽  
Experimental Techniques ◽  
Embedded Structures ◽  
Element Method

Abstract Calculation of the dynamic response of sensitive structures like foundations for vibrating machinery requires to take the interaction with subsoil into account. Structures and soil are discretized by boundary elements and coupled by a substructure technique. Viscoelastic constitutive equations contain fractional time derivatives. Surface waves generated by machine foundations and diffracted by embedded structures and soil inhomogeneities are analyzed by conventional and optoelectronic experimental techniques and calculated by the boundary element method (BEM).

scholarly journals AN ANALYTICAL MODEL ON STATIC SMOKE EXHAUST IN ATRIA

2010 ◽  
Vol 16 (3) ◽  
pp. 372-381 ◽  
Author(s):  
Cheuk Lun Chow ◽  
Junmei Li
Keyword(s):  
Fluid Dynamics ◽  
Driving Force ◽  
Natural Ventilation ◽  
Flow Model ◽  
Far East ◽  
Field Tests ◽  
The Far East ◽  
Smoke Layer ◽  
Simple Flow ◽  
Exhaust Systems

Static smoke exhaust systems with natural vents are starting to be installed in big shopping complexes, ware‐houses and cargo terminals in the Far East. These systems are used for natural ventilation as well as for letting out smoke. This paper responds to concerns over the performance of static smoke exhaust systems, which remain less popular than dynamic smoke exhaust systems with mechanical fans. We propose a modification of a simple flow model found in the literature, adapting this to study smoke layer interface height with natural vents opened. We compare and justify our results, as generated by both Computational Fluid Dynamics and zone models, alongside reports of historical field tests. The model of smoke exhaust is applied in an illustrative example of a large hall, leading to the suggestion that a flow model could be used for designing natural vents. As the key driving force in removing smoke through natural vents is smoke's own buoyancy, the system might only be effective for bigger fires. Santrauka Tolimuosiuose Rytuose statines dūmu šalinimo sistemos su natūralios ventiliacijos angomis pradedamos irengti dideliuose prekybos kompleksuose, sandeliuose ir kroviniu terminaluose. Tokios sistemos naudojamos ir natūraliai ventiliacijai, ir dūmams šalinti. Šis straipsnis parengtas susirūpinus, kad statines dūmu išmetimo sistemos yra ne tokios populiarios nei dinamines dūmu išmetimo sistemos su mechaniniais ventiliatoriais. Autoriai siūlo literatūroje aprašomo paprasto srauto modelio modifikacija, pritaikant ši modeli dūmu sluoksnio salyčio su natūralios ventiliacijos angomis aukščiui tirti. Straipsnyje palyginti ir pagristi rezultatai, gauti taikant tiek skaičiuojamosios skysčiu dinamikos, tiek zonavimo modelius kartu su eksperimentiniais tyrimais vietoveje. Pateiktas dūmu šalinimo modelio taikymo pavyzdys dideleje saleje ir padaryta išvada, kad srauto modelis galetu būti taikomas irengiant natūralia ventiliacija. Kadangi pagrindine varomoji jega šalinant dūmus per natūralias ventiliacijos angas yra dūmu plūdrumas, sistema gali būti veiksminga tik esant didesniems gaisrams.

scholarly journals Research on Formation Mechanism of Dynamic Response and Residual Stress of Sheet Metal Induced by Laser Shock Wave

2018 ◽  
Vol 167 ◽  
pp. 05007
Author(s):  
Aixin Feng ◽  
Yupeng Cao ◽  
Heng Wang ◽  
Zhengang Zhang
Keyword(s):  
Shock Wave ◽  
Residual Stress ◽  
Dynamic Response ◽  
Formation Mechanism ◽  
Experimental Studies ◽  
Material Surface ◽  
Propagation Mechanism ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Laser Shock Wave

In order to reveal the quantitative control of the residual stress on the surface of metal materials, the relevant theoretical and experimental studies were carried out to investigate the dynamic response of metal thin plates and the formation mechanism of residual stress induced by laser shock wave. In this paper, the latest research trends on the surface residual stress of laser shock processing technology were elaborated. The main progress of laser shock wave propagation mechanism and dynamic response, laser shock, and surface residual stress were discussed. It is pointed out that the multi-scale characterization of laser and material, surface residual stress and microstructure change is a new hotspot in laser shock strengthening technology.

The Critical Densimetric Froude Number of Subaqueous Gravity Currents Can Be Non-Unity or Non-Existent

2009 ◽  
Vol 79 (7) ◽  
pp. 479-485 ◽  
Author(s):  
H. Huang ◽  
J. Imran ◽  
C. Pirmez ◽  
Q. Zhang ◽  
G. Chen
Keyword(s):  
Froude Number ◽  
Gravity Currents ◽  
Densimetric Froude Number

scholarly journals The Dynamic Response of Tuned Impact Absorbers for Rotating Flexible Structures

2005 ◽  
Vol 1 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Steven W. Shaw ◽  
Christophe Pierre
Keyword(s):  
Dynamic Response ◽  
Flexible Structures ◽  
Experimental Studies ◽  
Analytical Investigation ◽  
Design Parameters ◽  
System Response ◽  
Rotor Speed ◽  
Flexible System ◽  
Restoring Forces ◽  
And Performance

This paper describes an analytical investigation of the dynamic response and performance of impact vibration absorbers fitted to flexible structures that are attached to a rotating hub. This work was motivated by experimental studies at NASA, which demonstrated the effectiveness of these types of absorbers for reducing resonant transverse vibrations in periodically excited rotating plates. Here we show how an idealized model can be used to describe the essential dynamics of these systems, and used to predict absorber performance. The absorbers use centrifugally induced restoring forces so that their nonimpacting dynamics are tuned to a given order of rotation, whereas their large amplitude dynamics involve impacts with the primary flexible system. The linearized, nonimpacting dynamics are first explored in detail, and it is shown that the response of the system has some rather unique features as the hub rotor speed is varied. A class of symmetric impacting motions is also analyzed and used to predict the effectiveness of the absorber when operating in its impacting mode. It is observed that two different types of grazing bifurcations take place as the rotor speed is varied through resonance, and their influence on absorber performance is described. The analytical results for the symmetric impacting motions are also used to generate curves that show how important absorber design parameters—including mass, coefficient of restitution, and tuning—affect the system response. These results provide a method for quickly evaluating and comparing proposed absorber designs.

Inviscid instability of an unbounded heterogeneous shear layer

1971 ◽  
Vol 48 (2) ◽  
pp. 405-415 ◽  
Author(s):  
S. A. Maslowe ◽  
R. E. Kelly
Keyword(s):  
Growth Rate ◽  
Froude Number ◽  
Mixing Layer ◽  
Density Variation ◽  
Wave Number ◽  
Unstable Wave ◽  
Number Range ◽  
Spatial Growth ◽  
Wave Number Range ◽  
Low Froude Number

Stability curves are computed for both spatially and temporally growing disturbances in a stratified mixing layer between two uniform streams. The low Froude number limit, in which the effects of buoyancy predominate, and the high Froude number limit, in which the effects of density variation are manifested by the inertial terms of the vorticity equation, are considered as limiting cases. For the buoyant case, although the spatial growth rates can be predicted reasonably well by suitable use of the results for temporal growth, spatially growing disturbances appear to have high group velocities near the lower cutoff wave-number. For the inertial case, it is demonstrated that density variations can be destabilizing. More precisely, when the stream with the higher velocity has the lower density, both the wave-number range of unstable disturbances and the maximum spatial growth rate are increased relative to the case of homogeneous flow. Finally, it is shown how the growth rate of the most unstable wave in the inertial case diminishes as buoyancy becomes important.

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