| 1. |
- Aboulila, Tarek Selim, et al.
(författare)
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Field experiment and numerical simulation of point source irrigation with multiple tracers.
- 2013
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Ingår i: International Journal of Sustainable Water and Environmental Systems. - 1923-7545.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- In this study, three plots in sandy soil in northern Tunisia were irrigated by a single irrigation dripper with a solution containing dye and bromide for three successive hours. Fifteen hours after ceasing of infiltration, horizontal 5 cm trenches were dug. Dye pattern, bromide concentration, and water content were recorded. Indication of preferential flow due to water repellency of initial dry soil was found during the early stages of infiltration. However no deep preferential flow occurred. This enables the use of drip irrigation to improve the sustainability of irrigation systems. Numerical simulation using Hydrus-2D was conducted for the field experiment. It was found that in both field experiments and numerical simulation the mobility of the bromide is different from the mobility of dye; the dye was retarded approximately twice by volume compared to bromide. The simulation results support the use of Hydrus-2D as a roughly, rapid and labor saving tool for investigation tracers’ mobility in sandy soil under point source irrigation.
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| 2. |
- Aboulila, Tarek Selim, et al.
(författare)
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Influence of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water on soil moisture and salinity distribution
- 2012
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Ingår i: Agricultural Water Management. - : Elsevier BV. - 1873-2283 .- 0378-3774. ; 103, s. 182-190
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Tidskriftsartikel (refereegranskat)abstract
- In alternate partial root-zone irrigation (APRI) a significant amount of irrigation water can be saved without considerable yield reduction. In this paper, Hydrus-2D/3D was used to investigate the impact of geometric design of alternate partial root-zone subsurface drip irrigation (APRSDI) with brackish water for growing tomato on soil moisture and salinity distribution. Three inter-plant emitter distances (IPED; 20, 30, and 40 cm), two emitter depths (10 and 20 cm), and three irrigation water salinity levels (0, 1, and 2 dS m-1) were used to implement the proposed simulation scenarios in loamy sand soil during a 40-day simulation period. The simulation results showed that higher soil moisture content was found beneath the plant trunk in case of 20 cm (short IPED) and near the domain border in case of 30 and 40 cm IPED. Short IPED guarantees more water in the maximum root density zone. A deeper wetting front occurred for deep emitter depth, while the wetting front reached the soil surface for shallow emitter depth. Salinity results revealed that as irrigation water salinity increased, the salinity in the top soil increased. In addition, the salinity at the soil surface increased as IPED and emitter depth increased. Higher root water uptake rates were recorded in the case of 20 cm IPED while the emitter depth did not show any considerable effect on root water uptake rates. Moreover, the applied irrigation water was fully consumed by the plant in case of short IPED. Emitter depth and salinity of irrigation water had negligible effect on amount of irrigation water extracted by plant roots and percolated amount below the bottom boundary of the flow domain. Overall, short IPED is recommended in APRSDI with or without brackish irrigation water regardless of the emitter depth.
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| 3. |
- Aboulila, Tarek Selim, et al.
(författare)
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Numerical evaluation of subsurface trickle irrigation with brackish water
- 2013
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Ingår i: Irrigation Science. - : Springer Science and Business Media LLC. - 0342-7188 .- 1432-1319. ; 31:5, s. 1125-1137
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Tidskriftsartikel (refereegranskat)abstract
- In this study, an assessment for a proposed irrigation system in the El-Salam Canal cultivated land, Egypt, was conducted. A numerical model (HYDRUS-2D/3D) was applied to investigate the effect of irrigation amount, frequency, and emitter depth on the wetted soil volume, soil salinity levels, and deep percolation under subsurface trickle irrigation (SDI) of tomato growing with brackish irrigation water in three different soil types. The simulations indicated that lower irrigation frequency increased the wetted soil volume without significant increase in water percolate below the plant roots. Deep percolation decreased as the amount of irrigation water and emitter depth decreased. With the same amount of irrigation water, the volume of leached soil was larger at lower irrigation frequency. The salinity of irrigation water under SDI with shallow emitter depth did not show any significant effect on increasing the soil salinity above tomato crop salt tolerance. Based on the results, it appears that the use of SDI with brackish irrigation water is an effective method for growing tomato crop in El-Salam Canal cultivated land especially with shallow emitter depth.
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| 4. |
- Aziz, Akram, et al.
(författare)
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Noninvasive Monitoring of Subsurface Soil Conditions to Evaluate the Efficacy of Mole Drain in Heavy Clay Soils
- 2023
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Ingår i: Water (Switzerland). - : MDPI AG. - 2073-4441. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Soil degradation and low productivity are among the major agricultural problems facing farmers of the newly reclaimed agricultural area in the Nile Delta region, Egypt. High content of clay and silt characterizes the soil texture of all farms in the area, while farmers still rely on the traditional mole drainage (MD) system to reduce the salinity of the farm soil. We present a comparison of innovative geo-resistivity methods to evaluate mole drains and the salinity affected clay soils. Geoelectrical surveys were conducted on three newly reclaimed farms to image the subsurface soil drainage conditions and to evaluate the efficiency of using the traditional MD systems in these heavy clay environments. The surveys included measuring the natural spontaneous potential (SP), apparent resistivity gradient (RG), and electrical resistivity tomography (ERT). Integrating the results of the three methods reduced the ambiguous interpretation of the inverted ERT models and allowed us to determine the subsurface soil structure. The inverted ERT models were suitable for locating the buried MDs and delineating the upper surface of the undisturbed clay beds. The proximity of these layers to the topsoil reduces the role played by MDs in draining the soil in the first farm and prevents the growth of deep-rooted plants in the second farm. Time-lapse ERT measurements on the third farm revealed a defect in its drainage network where the slope of the clay beds opposes the main direction of the MDs. That has completely obstructed the drainage system of the farm and caused waterlogging. The presented geo-resistivity methods show that integrated models can be used to improve the assessment of in situ sub-surface drainage in clay-rich soils.
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| 5. |
- El-Saadony, Mohamed T., et al.
(författare)
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Impacts of turmeric and its principal bioactive curcumin on human health: pharmaceutical, medicinal, and food applications : a comprehensive review
- 2023
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Ingår i: Frontiers in Nutrition. - : Frontiers Media S.A.. - 2296-861X. ; 9
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Forskningsöversikt (refereegranskat)abstract
- The yellow polyphenolic pigment known as curcumin, originating from the rhizome of the turmeric plant Curcuma longa L., has been utilized for ages in ancient medicine, as well as in cooking and food coloring. Recently, the biological activities of turmeric and curcumin have been thoroughly investigated. The studies mainly focused on their antioxidant, antitumor, anti-inflammatory, neuroprotective, hepatoprotective, and cardioprotective impacts. This review seeks to provide an in-depth, detailed discussion of curcumin usage within the food processing industries and its effect on health support and disease prevention. Curcumin’s bioavailability, bio-efficacy, and bio-safety characteristics, as well as its side effects and quality standards, are also discussed. Finally, curcumin’s multifaceted uses, food appeal enhancement, agro-industrial techniques counteracting its instability and low bioavailability, nanotechnology and focused drug delivery systems to increase its bioavailability, and prospective clinical use tactics are all discussed.
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| 6. |
- Hamed Abd El Mageed, Yasser, et al.
(författare)
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Assessment of heavy metals pollution and microbial contamination in water, sediments and fish of Lake Manzala, Egypt
- 2013
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Ingår i: Life Science Journal: Acta Zhengzhou University Overseas Edition. - 1097-8135. ; 10:1, s. 86-99
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this study is to assess the heavy metals pollution and microbial contamination in water, sediments and fish of Lake Manzala and study the direct and indirect effect for disposal of waste water, industrial and agricultural drainage water into the lake on the environmental situation. Samples were collected from four different sites in the lake and one site in the drain. The selected sites are exposed to direct and indirect industrial, municipal waste water and agricultural drainage disposals. A site near the connection between the lake and the sea was chosen as a possible unpolluted site to compare. Three water samples and one sediment sample were collected monthly from each site for thirteen months. Fish samples (Oreochromis niloticus) were collected randomly for eight months from different sites of the lake. Water salinity and pH values were measured to each site. Water, sediment and fish samples were analyzed for the concentration of five major heavy metals (Mn, Cd, Zn, Pb and Cu), and two groups of bacteria (Total viable bacteria TVB - faecal coliform bacteria FCB). Results show that all the water and sediment samples were collected from five sites contain different concentration of the five tested heavy metals. The highly polluted site with Zn, Pb, Cu in sediment was found in the drain as a result of the industrial disposal. The highly polluted site with Zn and Cu in water and Cd in sediment was found in site near the industrial area as a result of direct disposal of factories nearby. Although the site near the connection between the sea and the lake was assumed to be the purest site, It was found contained a maximum concentration of Pb in water. It is possibly due to the disposal from a new natural gas factories located near this area. All the five sites were contaminated with high rate of TVB and FCB in water which is an indicator of untreated waste water which spilled directly or indirectly to the lake. The most alarming result was found when analyzing fish; all the fish samples were contaminated on surface and internally with very high amounts of TVB and FCB at gill and intestine. Fish samples also had high concentrations of analyzed heavy metals at their flesh. The mean calculated value of Pb was high up to 38 times than the allowed permissible concentration. This confirms that lake fish is highly polluted and dangerous for human health.
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| 7. |
- Hamed Abd El Mageed, Yasser, et al.
(författare)
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Comparison between rainfall simulator erosion and observed reservoir sedimentation in an erosion-sensitive semiarid catchment
- 2002
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Ingår i: Catena. - 0341-8162. ; 50:1, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Estimating catchment scale soil loss based on rainfall simulators is often hampered by the difficulty to scale up simulator results. Our objective was to develop and test a method for estimating catchment scale soil loss based on observed rainfall using a variable intensity rainfall simulator in an erosion-sensitive catchment in semiarid Tunisia. A 7-year period, 1992-1999, with observed sedimentation amounts in a downstream reservoir was chosen to test a methodology. The methodology was based on (1) energy adjustment for the used simulator due to the difference in kinetic energy of simulated and natural rainfall at equal intensities and (2) upscaling of simulated erosion in which rill erosion was estimated by adjusting the difference between slope lengths for the plots versus the catchment after onset of runoff. The comparison between calculated soil loss from rainfall simulator experiments and observed sedimentation in the downstream reservoir displayed good overall results. Calculated soil loss was found to be about 96%, 36%, and 80% for different observed subperiods, respectively. The observed low value for the second period was probably due an exceptionally intense rainfall event during this period, which appears to have led to gully erosion, soil slide, and riverbank collapse. Therefore, during this event, siltation in the reservoir may essentially be due to unaccounted erosion processes such as gully erosion. Overall, however, it appears that plot-scale variable intensity rainfall simulators can rather successfully estimate catchment scale soil losses. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 8. |
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| 9. |
- Hamed Abd El Mageed, Yasser, et al.
(författare)
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Evaluation of the WET sensor compared to time domain reflectometry
- 2006
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Ingår i: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 51:4, s. 671-681
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Tidskriftsartikel (refereegranskat)abstract
- This paper concentrates on the experimental calibration of a rapid, non-destructive sensor to investigate the salinization process by measuring the dielectric properties of the soil to estimate both the soil water content (theta) and pore water electrical conductivity (sigma(p)) for different soil types. The proposed sensor depends on the frequency domain reflectometry (FDR) technique and is called the WET sensor. It estimates the dielectric permittivity (K-a) and bulk electrical conductivity (sigma(a)) of soil. Then, it utilizes both of them to estimate theta and sigma(p). The new sensor is compared to time domain reflectometry (TDR) measurements. Time domain reflectometry is a well established technique for K-a and sigma(a) measurements in soils. The study involves experimental measurements in the laboratory using five different soil types and a range of theta values. In each soil type, three different electrical conductivity solutions (sigma(w)) were used. The results revealed that the calibration coefficients of water content and the soil parameter are significantly dependent on the soil type and slightly affected by electrical conductivity of the moistening solution.
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| 10. |
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