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Present work evaluates the double averaged turbulence characteristics of the sand bed channel subjected to the downward seepage through permeable bed. Measures of turbulent statistics are observed to increase with the application of downward seepage. The form induced stress in near bed has a reducing effect with no seepage and an increasing effect with seepage. The seepage increases the turbulent kinetic energy and turbulent intensities causing the bed particles to move rapidly. The quadrant analysis suggests that at near bed, the sweep events in flows with seepage are the main bursting events towards the Reynolds stress production, while ejection and sweep events in no seepage flow have almost equal contribution. The increase in sediment transport with seepage is caused by an increase in flow turbulence production and an associated decrease in turbulent kinetic energy dissipation and turbulent diffusion. Key words: double averaged, flow characteristics, turbulence, seepage. La presente etude evalue les caracteristiques de turbulence a double moyenne d'un lit mobile de sable soumis a une perte par infiltration vers le bas a travers le lit permeable. On a observe que les mesures de statistiques de turbulence augmentent avec l'application d'infiltration vers le bas. La contrainte induite par la forme a proximite du lit a un effet de reduction sans infiltration et un effet d'augmentation avec infiltration. L'infiltration augmente l'energie cinetique turbulente et les intensites turbulentes causant le deplacement rapide des particules du lit. L'analyse des quadrants suggere qu'a proximite du lit les evenements de drague dans les cas d'ecoulements avec infiltration sont les principaux evenements de turbulence menant a la production de tension de Reynolds, tandis que les evenements d'ejection et de drague dans un cas d'ecoulement sans infiltration ont une contribution presque egale. L'augmentation du transport solide avec infiltration est causee par une augmentation de la production d'ecoulement turbulent et une diminution de la dissipation d'energie cinetique turbulente et de la diffusion turbulente. [Traduit par la Redaction] Mots-cles: double moyenne, caracteristiques d'ecoulements, turbulence, infiltration des eaux., Introduction Most of the river flow over the alluvial bed is turbulent in nature, which may be subjected to seepage due to porosity of the sand material and difference of [...]

In this study, experiments were performed in a curvilinear cross-sectional threshold alluvial channel with no seepage and with seepage conditions to understand the influence of downward seepage in an alluvial channel. We observed that a stable channel during the no seepage condition started to approach a stable channel in the transporting stage with downward seepage. Increased value of Shields stress was observed after the application of seepage. In addition, this study deals with the effect of downward seepage on the evolution of alluvial bedforms. In this regard, multi- temporal bed elevation profiles were collected along the test section of channel, which are used to characterize migrating bedforms. Results reveal greater fluctuations and variability on the channel bed under the influence of increased seepage discharge. Slope of the power spectral density with wave number was significantly increased with an increment in seepage percentage, showing more inhomogeneous arrangement of bedforms and larger roughness over the channel boundary. Key words: turbulence, seepage, multi-scalar fluctuation, power spectral density, structure function. Dans le cadre de cette etude, des experiences ont ete effectuees dans un prototype de lit a fond mobile, curviligne en coupe transversale, dans des conditions de non-infiltration et d'infiltration pour comprendre les effets d'infiltration vers le bas dans un lit a fond mobile. Nous avons observe qu'un lit stable pendant une condition de non-infiltration a commence a atteindre l'etape de transport avec l'infiltration vers le bas. Une valeur accrue de la contrainte de Shields a ete observee apres l'application d'infiltration. De plus, cette etude traite de l'effet d'une infiltration vers le bas sur l'evolution de la morphologie de fond. A cet egard, des profils de niveau du lit a plusieurs echelles temporelles ont ete amasses le long de la section d'essais du lit, ceux-ci etant utilises pour caracteriser l'evolution morphologique de fond. Les resultats revelent qu'il yade plus grandes fluctuations et une variabilite plus importante du lit sous l'effet de decharge accrue d'infiltration. La pente de la densite spectrale de puissance par rapport au nombre d'ondes a augmente significativement avec une augmentation du pourcentage d'infiltration, montrant un arrangement moins homogene des figures sedimentaires de fond et une plus grande rugosite aux rives. [Traduit par la Redaction] Mots-cles: turbulence, infiltration, fluctuation a plusieurs niveaux, densite spectrale de puissance, fonction de structure., Introduction The intrinsic behavior of mobile beds in natural environments is complex if one attempts to understand their innate creation. Mobile beds transform themselves and evolve into different patterns such [...]

Lung cancer is the leading cause of cancer-related deaths globally, accounting for 1.8 million fatalities in 2020. Genetic mutations, chromosomal abnormalities, transcription factors, mutations in tumor suppressor genes, and mutations in oncogenes have all been associated with an increased risk of LC development. Heterogeneity of the disease, resistance to chemotherapy, and side effects such as nausea and vomiting, fatigue, anemia, neuropathy, hair loss, and skin and nail changes are associated with conventional therapeutics such as chemotherapy, radiation therapy, and targeted therapy. Thus, the treatment of the disease urgently requires the discovery of novel therapeutic approaches. This review identifies and discusses key molecular and genetic targets for LC therapy, highlighting recent advancements and potential clinical applications. Our efforts encompass all biological targets and aim to increase our understanding of these processes to better comprehend the disease's molecular mechanisms and develop new drugs and more effective LC treatments. [ABSTRACT FROM AUTHOR]

Channel dredging has become a common phenomenon across several fluvial systems. Pits dredged in the riverbank can influence the downstream turbulence and affect the bank slope and central channel morphodynamics. Erodible bed experiments were conducted in a laboratory flume having a riverbank cross section with three different bank slopes, i.e., 25°, 31°, and 40° with and without a mining pit. Flow over the bank slope and near the bank toe was most affected by the pit excavation at the channel upstream. Turbulence levels were amplified within the flow over the slope and near the bank toe. The logarithmic scaling range of higher-order fluctuations at the bank toe is greater for with pit case. The complex interaction of simultaneous processes like pit migration, sliding failure and bank erosion, and fluvial erosion was studied at multiple length scales and time scales. A wavelet cross correlation analysis was used to calculate the celerity of bedform migration at the bank toe along the flow. Statistical celerity of bedforms with smaller scales (up to 15 mm length scales) is significantly higher due to pit interaction. The study reveals that instream mining has notable effects on the inherent nature of higher-order turbulence statistics, especially near the bank slope and toe, as well as the multiscale morphological structures. [ABSTRACT FROM AUTHOR]

Seepage is one of the important factors involved in natural flow conditions, contributing to changes in flow turbulence patterns and morphological changes due to the transport of sediments. This transport of sediment particles influences the development of fluvial bedforms in any river channel. However, previous research on fluvial dynamics has not considered the influence of seepage on the flow field over the fluvial bedforms. The present experimental research aims to explore the behavioral patterns of turbulent kinetic energy, the turbulent kinetic energy (TKE) budget, and quadrant analysis for flows over two-dimensional dune shaped bedforms in the absence and presence of downward seepage. Results from the study illustrate that at the measurement locations on the initial and lee side sections of a dune, the TKE increases with the introduction of downward seepage, leading to an increase in turbulence production near the bed-surface region. The flow energy under both no seepage and seepage conditions contributes mainly to the turbulent production. Turbulence diffusion and dissipation rates have been found to decline in the near-bed region of the initial and lee side sections of the dune. However, turbulent production has been found to be significantly higher in the presence of downward seepage than under the no seepage condition. Similarly, turbulent kinetic energy flux increases in the streamwise direction, while it reduces in the vertical direction at initial sections and lee side sections of the dune under seepage conditions. However, at the middle sections and crest portion of the dune, opposite behavioral patterns are observed for all the aforementioned turbulent entities. Quadrant analysis reveals that the sweep and ejection event increases while inward and outward interaction reduces in the near bed zone. Although the contribution of both sweep and ejection events increases in the presence of downward seepage, sweep events have clear dominance in the near bed region, suggesting the possibility of a higher rate and amount of sediment transportation than under the no seepage condition. [ABSTRACT FROM AUTHOR]

Riverbank erosion has significant geomorphological as well as anthropogenic consequences. The geomorphological impacts include form changes such as lateral channel migration, meanders, channel expansion, etc. The anthropogenic effects include the threat to floodplain human habitation, agricultural land, and stability of instream hydraulic structures and buried pipelines. Channel dredging for the extraction of sand and gravel has seen a multi‐fold rise in the last few decades. Therefore, riverbank erosion response to channel mining gains importance in river basin management. Sandpits dredged in the riverbeds can significantly impact the downstream riverbank stability. In order to assess these impacts, we conducted a series of experiments at a laboratory scale in a recirculating water flume. Three riverbank slopes, 25° (gentle), 31° (equal to the angle of repose of the bank sediments), and 40° (steeper than the angle of repose), were tested along with a sandpit. Remarkable changes in the turbulence structure of riverbank flow were found due to the channel pit. Pit excavation directly impacts the fluvial erosion characteristics of the riverbank. Pit action increases the Reynolds shear stress fields in the near‐bank flow, which causes progressive fluvial erosion of the berm at the bank toe. The erosivity of the main channel flow in the riverbank also leads to channel degradation, which increases the exposed height of the bank slope. Pit dredging leads to the generation of stronger ejection bursts which provide a mechanism for berm sediment mobility and erosion. The hydro morphological response of the riverbank due to sand mining was analysed, and process understandings are presented in the paper. [ABSTRACT FROM AUTHOR]