horizontal flows
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2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Daya Thussu

Abstract In the era of digitized and globalized 24/7 communication, the one-way vertical flow of media and mediated culture from the West to the East has given way to multiple and horizontal flows, in which Asian countries are playing an increasingly significant role. This is having a profound impact on transcultural communication in a polycentric world. Although the United States and some other western countries still maintain their leading position in the field of global media and communication hardware and software. This article suggests that new actors, harnessing the potential of digital globalization, have emerged in the past decade and provide new avenues for transnational communication. Such changes, it argues, warrant a re-evaluation of how we define the global in terms of media and communication. Focusing on the growing global influence and digital presence of China and other Asian countries, the article suggests that the ascent of Asia contributes to further internationalizing of media and its study.


Author(s):  
Gerardo Hernández-Dueñas ◽  
M.-Pascale Lelong ◽  
Leslie M. Smith

AbstractSubmesoscale lateral transport of Lagrangian particles in pycnocline conditions is investigated by means of idealized numerical simulations with reduced-interaction models. Using a projection technique, the models are formulated in terms of wave-mode and vortical-mode nonlinear interactions, and they range in complexity from full Boussinesq to waves-only and vortical-modes-only (QG) models. We find that, on these scales, most of the dispersion is done by vortical motions, but waves cannot be discounted because they play an important, albeit indirect, role. In particular, we show that waves are instrumental in filling out the spectra of vortical-mode energy at smaller scales through non-resonant vortex-wave-wave triad interactions. We demonstrate that a richer spectrum of vortical modes in the presence of waves enhances the effective lateral diffusivity, compared to QG. Waves also transfer energy upscale to vertically sheared horizontal flows which are a key ingredient for internal-wave shear dispersion. In the waves-only model, the dispersion rate is an order of magnitude smaller and is attributed entirely to internal-wave shear dispersion.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Ekhwaiter Abobaker ◽  
Abadelhalim Elsanoose ◽  
Faisal Khan ◽  
Mohammad Azizur Rahman ◽  
Amer Aborig ◽  
...  

A number of different factors can affect flow performance in perforated completions, such as perforation density, perforation damage, and tunnel geometry. In perforation damage, any compaction at the perforation tunnels will lead to reduced permeability, more significant pressure drop, and lower productivity of the reservoir. The reduced permeability of the crushed zone around the perforation can be formulated as a crushed-zone skin factor. For reservoir flow, earlier research studies show how crushed (compacted) zones cause heightened resistance in radially converging vertical and horizontal flow entering perforations. However, the effects related to crushed zones on the total skin factor are still a moot point, especially for horizontal flows in perforations. Therefore, the present study will look into the varied effects occurring in the crushed zone in relation to the vertical and horizontal flows. The experimental test was carried out using a geotechnical radial flow set-up to measure the differential pressure in the perforation tunnel with a crushed zone. Computational fluid dynamics (CFD) software was used for simulating pressure gradient in a cylindrical perforation tunnel. The single-phase water was radially injected into the core sample with the same flow boundary conditions in the experimental and numerical procedures. In this work, two crushed zone configuration scenarios were applied in conjunction with different perforation parameters, perforation length, crushed zone radius, and crushed zone permeability. In the initial scenario, the crushed zone is assumed to be located at the perforation tunnel’s side only, while in the second scenario, the crushed zone is assumed to be located at a side and the tip of perforation (a tip-crushed zone). The simulated results indicate a good comparison with regard to the two scenarios’ pressure gradients. Furthermore, the simulations’ comparison reveals another pressure drop caused by the tip crushed zone related to the horizontal or plane flow in the perforations. The differences between the two simulations’ results show that currently available models for estimating the skin factor for vertical perforated completions need to be improved based on which of the two cases is closer to reality. This study has presented a better understanding of crushed zone characteristics by employing a different approach to the composition and shape of the crushed zone and permeability reduction levels for the crushed zone in the axial direction of the perforation.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1780
Author(s):  
Elad Ben-Zur ◽  
Haim Gvirtzman ◽  
Eyal Shalev

Sea-tide effects on the fresh-saline water interface (FSI) in a stratified coastal aquifer are examined through laboratory experiments. The physical model, a two-dimensional rectangular flow tank, is filled with layered aquifers and aquitards. The aquifers serve as the main entrances/exits of water to/from the system through significant horizontal flows, creating unstable conditions of heavier saline water above lighter freshwater for short periods of time. Several processes create mixing; this instability results in haline convection, creating downward fingering, stable rising of horizontal saltwater front, and unstable upward fingerings of flushing freshwater. The time lag between the sea tide fluctuations and the emergence of adequate fresh- and saltwater is higher in a stratified system compared to a homogeneous system. Furthermore, longer tide cycles lead to the enlargement of the FSI’s toe horizontal movement range. The combination of tidal forcing with a layering aquifer structure leads to a wider FSI by creating a significant salt- and freshwater mixing inside each layer, vertical flows between the layers, and saltwater bodies at isolated areas. Haline convection within the FSI might be the reason for the wider fresh-saline interfaces that are found in field studies.


Author(s):  
Paul Haacke

The Coda considers how the book’s historical critique of modernist verticality can help us develop more nuanced ways of rethinking more current discourses of the horizontal imagination, including decades-old arguments about the “depthlessness,” “shallowness,” and “groundlessness” of contemporary culture as well as the rhetoric of horizontal flows, digital utopias, and the global commons. In particular, it calls for further recognition of the growing ecological crisis and the persistence of social stratification and uneven development despite calls for “flat” conceptions of the social. It concludes by arguing that a more multi-layered and multi-dimensional understanding of the past and the future may be necessary for confronting the challenges of the present.


2020 ◽  
Vol 641 ◽  
pp. A50
Author(s):  
T. Roudier ◽  
J. M. Malherbe ◽  
B. Gelly ◽  
R. Douet ◽  
Z. Frank ◽  
...  

Exploding granules constitute the strongest horizontal flows on the quiet Sun and contribute to the structure of the surface horizontal velocity fields which build the large-scale organization of the discrete magnetic field. In this work we explore exploding granule expansion through the observations of the ground-based THEMIS telescope, IRIS, SDO, and the Hinode space-borne instruments, and finally with the magnetohydrodynamics simulation. We evaluate the detection and the expansion of exploding granules at several wavelengths and at various spatial and temporal resolutions. To analyze the different temporal sequences, two methods of image segmentation are applied to select the granules. The first allows us to follow individually the exploding granules observed simultaneously by THEMIS, IRIS, and SDO. The second uses long time independent sequences from THEMIS, IRIS, SDO, Hinode, and a simulation. In the first method (called manual) the segmentation isolates the cell of the granules (bright granules and intergranular parts), while in the second method (called statistical) only the bright part of the granules are isolated. The results obtained with simultaneous or distinct temporal observations using the two methods of segmentation are in good agreement. The granule area evolves linearly with an expansion velocity that decreases with the radius. A rapid decrease in the velocity expansion in the first two minutes is observed. The detection and measurement of the dynamics of the explosive granules can be performed from ground- and space-based instruments. Our work reveals the usefulness of SDO data, with low spatial resolution, to study the dynamics of the exploding granules all over the solar surface.


Author(s):  
G.Kh. Ismaiylov ◽  
◽  
N.V. Muraschenkova ◽  

The construction of a mathematical model of the water-salt balance for river basins with the predominant development of irrigated agriculture is considered. The structures of the water and salt balance of the irrigated territory and the balance of the main river bed within it are given. It has been established that if the inflow and outflow of water and salts dissolved in it are caused by its horizontal flows, then the evaporation and accumulation of water (salts) in the aeration zone and groundwater are caused by its vertical flows.This leads to the need to consider instead of the general equation of the water (salt) balance of the irrigated territory of its modifications for the distinguished three vertical zones, that is, “the surface of the territory – aeration zone – groundwater zone”. During the operation of the algorithm, the following are successively determined: elements of the water and salt balance of the irrigated territory and the riverbed; groundwater level as a result of the intake of salts with in-person flow of local tributaries; filtration losses from the channels and the lateral residue of the inflow; moisture content in the aeration zone after irrigation water and precipitation enters it; groundwater level after water from the aeration zone; moisture content in the aeration zone after the influx of groundwater into it; the outflow of groundwater into the riverbed and the final mineralization of water in the aeration zone.


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