Influence of Pumps on Salinity of a Coastal Aquifer with Legal Protection (A Zone in the North of Isla Cristina, Huelva, Spain)

1991 ◽  
Vol 24 (11) ◽  
pp. 251-260 ◽  
Author(s):  
A. González ◽  
E. Romero
Keyword(s):  
Coastal Aquifer ◽  
Salt Water ◽  
Legal Protection ◽  
Hydraulic Gradient ◽  
Water Mixture ◽  
Residual Flow ◽  
Legal Requirements ◽  
The North ◽  
North Side ◽  
Rational Distribution

In this article we show that the legal measures for protection of aquifers are not enough to lessen the pumping if the users are not associated and determined to have a rational distribution of water. The expansive agriculture on the North side of Isla Cristina (Huelva, Spain), based on citrus and strawberry growing, uses high volumes of groundwater that comes from a tertiary age detritic coastal aquifer with a significant lack of resources. This causes a decrease of the residual flow to the sea, deep pumpcones, and an inversion of the hydraulic gradient, which initiates the progressive salinization of the aquifer northwards, in the sense that the fresh-salt water mixture zone is moving. The problem is worsening because the number of uncontrolled pump-works in the areais increasing. This problem could be alleviated if a Users Community for the whole aquifer were created, itself to watch over the fulfilment of the legal requirements and to regulate the water extractions.

scholarly journals Applications of intraoperative Duplex ultrasound in vascular surgery: a systematic review

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Pasha Normahani ◽  
Bilal Khan ◽  
Viknesh Sounderajah ◽  
Sepideh Poushpas ◽  
Muzaffar Anwar ◽  
...  
Keyword(s):  
Bypass Surgery ◽  
Duplex Ultrasound ◽  
Residual Flow ◽  
Scanning Strategy ◽  
Adjusted Risk ◽  
Conflicting Evidence ◽  
Carotid Artery Endarterectomy ◽  
The Impact ◽  
Modest Reduction

Abstract Objective This review aims to summarise the contemporary uses of intraoperative completion Duplex ultrasound (IODUS) for the assessment of lower extremity bypass surgery (LEB) and carotid artery endarterectomy (CEA). Methods We performed a systematic literature search using the databases of MEDLINE. Eligible studies evaluated the use of IODUS during LEB or CEA. Results We found 22 eligible studies; 16 considered the use of IODUS in CEA and 6 in LEB. There was considerable heterogeneity between studies in terms of intervention, outcome measures and follow-up. In the assessment of CEA, there is conflicting evidence regarding the benefits of completion imaging. However, analysis from the largest study suggests a modest reduction in adjusted risk of stroke/mortality when using IODUS selectively (RR 0.74, CI 0.63–0.88, p = 0.001). Evidence also suggests that uncorrected residual flow abnormalities detected on IODUS are associated with higher rates of restenosis (range 2.1% to 20%). In the assessment of LEB, we found a paucity of evidence when considering the benefit of IODUS on patency rates or when considering its utility as compared to other imaging modalities. However, the available evidence suggests higher rates of thrombosis or secondary intervention in grafts with uncorrected residual flow abnormalities (up to 36% at 3 months). Conclusions IODUS can be used to detect defects in both CEA and LEB procedures. However, there is a need for more robust prospective studies to determine the best scanning strategy, criteria for intervention and the impact on clinical outcomes.

scholarly journals Carotid wall imaging with 3D_T2_FFE: sequence parameter optimization and comparison with 3D_T2_SPACE

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ang Yang ◽  
Xue Hong Xiao ◽  
Zhi Long Wang ◽  
Yong Xin Zhang ◽  
Ke Yi Wang
Keyword(s):  
Cerebellopontine Angle ◽  
Carotid Bifurcation ◽  
Black Blood ◽  
Residual Flow ◽  
Flow Signal ◽  
Good Imaging ◽  
Significant Difference ◽  
Carotid Wall ◽  
Fast Field ◽  
Wall Imaging

AbstractSimilar to sampling perfection with application-optimized contrast using different flip angle evolutions (SPACE), T2-weighted fast field echo (FFE) also has a black blood effect and a high imaging efficiency. The purpose of this study was to optimize 3D_T2_FFE and compare it with 3D_T2_SPACE for carotid imaging. The scanning parameter of 3D_T2_FFE was optimized for the imaging of the carotid wall. Twenty healthy volunteers and 10 patients with carotid plaque underwent cervical 3D_T2_FFE and 3D_T2_SPACE examinations. The signal-to-noise ratios of the carotid wall (SNRwall) and lumen (SNRlumen), and the contrast-to-noise ratios between the wall and lumen (CNRwall_lumen) were compared. The incidence of the residual flow signal at the carotid bifurcation and the grades of flow voids in the cerebellopontine angle region in the two sequences were also compared. The reproducibility of the two sequences was tested. No significant difference was observed between the two sequences in terms of the SNRwall of healthy individuals and patients (P = 0.132 and 0.102, respectively). The SNRlumen in the 3D_T2_FFE images was lower than that in the 3D_T2_SPACE images. No significant difference was observed between the two sequences in terms of the CNRwall-lumen. The incidence of the residual flow signal at the carotid bifurcation in 3D_T2_FFE was significantly lower than that in 3D_T2_SPACE. The grades of flow suppression in the cerebellopontine angle region in 3D_T2_SPACE was lower than that in 3D_T2_FFE. Both sequences showed excellent inter-and intra-observer reproducibility. Compared to 3D_T2_SPACE, 3D_T2_FFE showed stronger flow suppression while maintaining good imaging quality, which can be used as an alternative tool for carotid imaging.

A numerical study of residual flow induced by eddy viscosity-shear covariance in a tidally energetic estuary

2019 ◽  
Vol 230 ◽  
pp. 106446 ◽  
Author(s):  
Peng Cheng ◽  
Jianshan Mao ◽  
Fengling Yu ◽  
Nengwang Chen ◽  
Aijun Wang ◽  
...  
Keyword(s):  
Eddy Viscosity ◽  
Numerical Study ◽  
Residual Flow

scholarly journals TIDE AND TIDAL CURRENT IN THE BALI STRAIT, INDONESIA

2015 ◽  
Vol 36 (2) ◽  
pp. 25-36 ◽  
Author(s):  
Dessy Berlianty ◽  
Tetsuo Yanagi
Keyword(s):  
Tidal Current ◽  
Ecological Model ◽  
Current Model ◽  
Spring Tide ◽  
Residual Flow ◽  
Tidal Front ◽  
Shelf Seas ◽  
Shallow Area ◽  
Tidal Constituents ◽  
Tide And Tidal Current

Tide and tidal current model of the Bali Strait in Indonesia is produced by using a Coupled Hydrodynamical-Ecological Model for Regional and Shelf Seas (COHERENS). With its resolutions in the horizontal (500meters) and the vertical (4layers), the model well reproduces the four major tidal constituents, namely M2, S2, K1, and O1 tides, and their currents. Furthermore the model is used to investigate the tide-induced residual flow and tidal front in the Bali Strait. As a results, the tide-induced residual flow in the Bali Strait during the spring tide on May 16th in 2010 can be attributed to the variation of the strength of two eddies. The first one is the clockwise circulation in the shallow area at the wide part of the strait, while the second one is the small clockwise circulation in the south of the narrow strait. On the other hand, as suggestion from Simpson and Hunter (1974), the tidal front is determined by the value of log(H/U3) (where is the water depth in meters and the amplitude oftidal current amplitude in ms-1). The front detected by the image of sea surface temperature distribution from the satellite corresponds with the contour log(H/U3) of 6.5.

The effect of magnetic flutter on residual flow

2013 ◽  
Vol 20 (11) ◽  
pp. 112502 ◽  
Author(s):  
P. W. Terry ◽  
M. J. Pueschel ◽  
D. Carmody ◽  
W. M. Nevins
Keyword(s):  
Residual Flow

Study of the Residual Flow and Salinity during the Spring and Neap Tides at the Seokmo Channel, South Korea

2016 ◽  
Vol 75 (sp1) ◽  
pp. 1422-1426
Author(s):  
Byung Il Yoon ◽  
Nakyong Choi ◽  
Bon-Ho Gu ◽  
Jong Wook Kim ◽  
Jin Il Song ◽  
...  
Keyword(s):  
South Korea ◽  
Residual Flow
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