The Upper Eocene–Oligocene sequence exposed northwest Birket Qarun; Fayum district covers two rock units, Qasr ElSagha (Temple and Dir Abu Lifa members) and Gebel Qatrani formations were re-evaluated by sequence stratigraphy. Six depositional sequences were recognized based on facies geometry, and sedimentological aspects. The frst sequence (Temple Member) was accumulated under marginal intertidal fat environment indicating highstand deposits. The second (the lower Dir Abu Lifa Member) displays a regressive sedimentary facies starting with progradational delta front environment refecting lowstand deposits followed upward by a lagoonal environment indicating transgressive/highstand deposits. The third (the top of the Dir Abu Lifa Member) was accumulated under a low sinuosity stream refecting lowstand deposits. The fourth which constitutes the topmost of Dir Abu Lifa Member initiating near-shore shallow marine points to transgressive sediments, followed upward by fuvial sediments refecting highstand deposits. The ffth (the Lower of Gebel Qatrani Formation) accumulated as point-bar deposits demonstrating lowstand deposits. The last occupies the main of Gebel Qatrani Formation initiates with restricted riverine marking lowstand deposits, followed upward by several fning upward cycles that were accumulated in fuvial and food plain conditions with evidence of tidal infuence on sedimentation near its top denoting transgressive deposits. Several minor transgressive episodes accompanied by tidal infuence on sedimentation are noticed near the top, which may refect gradual subsidence of the Oligocene alluvial plain. The area is subjected to relative sea-level changes that show a similarity with the global sea level. The base-level fuctuations are mainly controlled by the regional tectonic setting.
Abstract
We report here structural morphology and nonlinear behavior of pure and co-doped Zn0.90-
xFe0.1MxO with (M = Cu, Ni and
(x = 0.00, 0.10) and (0.00 ≤ y ≤ 0.20)) at different sintering temperatures (Ts = 850 and 1000 °C). It is found that the co-doping
of ZnO by (Fe + Cu) or (Fe + Ni) up to 0.30 does not deform the well-known wurtzite structure of ZnO, as well as pure and
0.1 of Fe-doped ZnO. The SEM micrographs did not show any secondary phases at the boundaries of grains as compared
to ZnO, the average grain size is decreased for Fe and (Fe + Cu) samples, while it is increased for (Fe + Ni) samples. The
nonlinear coefficient α and breakdown field EB are generally increased by 0.1 of Fe addition, but they are shifted to lower
values as Ts increases for all samples. Furthermore, they are gradually increased/decreased to higher/lower values for
(Fe + Cu/Fe + Ni) samples up to 0.30 of co-doping content. The values of α and EB are increased from 30.06, 2115.38 V/cm
for ZnO at 850 °C to 50.07, 5012 V/cm by (0.1Fe + 0.2Cu) co-doping, and from 23.53, 1956.52 V/cm to 45.58, 4750 V/cm
at 1000 °C, while they are, respectively, decreased by (0.1Fe + 0.2Ni) to 13.19, 312 V/cm and 11.85, 172.42 V/cm. Similar
behavior was generally obtained for nonlinear conductivity σL and height of potential barrier φB, whereas the vice is versa
for the behavior of leakage current Jk and residual voltage Kr. Our results are discussed in terms of the comparative participation
between the effects of co-doping of (Fe + Cu) and (Fe + Ni) to ZnO for supporting the potential barrier as compared to
individual doping by Fe, Cu and Ni. This study perhaps recommended these samples for optoelectronic and ferromagnetic
investigation after COVID-19 is over.
We report here the synthesis of silver nanoparticles (AgNPs) from an aqueous extract of Juniperus excelsa and their use as an antimicrobial agent on their own or in combination with antibiotics in inhibiting multidrug-resistant bacteria (MDR). One strategy of bacterial infection control in wound healing is AgNP biosynthesis. We collected bacterial strains of patient skin infections from Al-Adwani Hospital. Phenotyping, biotyping, and molecular characterizations were applied using 16S rRNA gene analysis of bacterial isolates. Our results identified tested MDR bacteria Staphylococcus aureus strains (methicillin-resistant and methicillin-susceptible) and Proteus mirabilis. Gas chromatography/mass spectrometry (GC/MS) analysis was used to identify the Juniperus excelsa biomolecules in the leaf extract acting as both reducing and capping agents in the biosynthesis of AgNPs. The AgNPs appeared hexagonal and spherical in shape upon transmission electron microscope (TEM) analysis. The AgNP sizes ranged from 16.08 to 24.42 nm. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the particles. The minimum inhibitory concentrations (MICs) of the AgNPs against the tested MDR bacteria ranged from 48 to 56 µg/ml, while the minimum bactericidal concentrations (MBCs) of the AgNPs against the tested strains ranged from 72 to 96 µg/ml. The AgNPs showed a good synergistic efficacy with Cefaclor, Cefoxitin, and Erythromycin. Their efficiency showed a threefold increase in the inhibition of tested strains when used in wound dressing, due to the AgNPs potentially activating the antibiotics. Consequently, we can use AgNPs with Cefaclor, Cefoxitin, and Erythromycin antibiotics as alternative antimicrobial agents, and they could be utilized in wound dressing to prevent microbial infections.
Gravity Recovery and Climate Experiment (GRACE) data with other data sets are used to estimate the mass variations over the Eastern Desert. These variations are caused by changes in terrestrial water storage (ΔTWS). Monthly GRACE and Mascon Solutions with other relevant data are conducted. Findings are (1) the Eastern Desert is witnessing a dry climatic period (April 2002 to July 2012) with lower average annual precipitation (AAP) rate of 9.3 mm and a wet climatic period (August 2012 to July 2016) with slightly higher precipitation rate of 14.1 mm; (2) the average trends in ΔTWS over the study area are estimated at − 4.40 ± 0.63 mm/year and + 4.37 ± 20.7 mm/year during the dry and wet periods, respectively; (3) the spatial distribution of the ΔTWS values during the wet period are consistent with the distribution of the rainfall, and the water leakage from Lake Nasser towards the surroundings though fault conduits; (4) the groundwater storage variation (ΔGWS) shows a negative trend of − 3.95 ± 0.63 mm/year during the dry period, while it shows a positive trend of + 4.98 ± 2.00 mm/year for the wet period; (5) Lake Nasser shows slightly higher water level variations during the wet period, in comparison to that of the dry period; (6) the surface water is draining eastward into the Red Sea and westward into the Nile River and partially feeding the underground aquifers through the permeable outcrops and/or along the sub-vertical deep-seated faults. Results provide new information on the mass variations of the Eastern Desert, caused by the change in the water storage in response to the climatic variation and global warming. The lowlands of the main valleys may represent the promising areas for agricultural development in the Eastern Desert.
An integrated approach of Gravity Recovery and Climate Experiment (GRACE) and vertical electrical resistivity sounding (VES) technique has been carried out to investigate regionally and locally the groundwater potentialities of Wadi Sar in the Hijaz Mountains. Our findings are (1) the terrestrial water storage variations (ΔTWS) are estimated at −2.06±0.34 mm/year; (2) the Global Land Data Assimilation System–derived soil moisture storage variations (ΔSMS) are estimated at −0.067±0.005 mm/year; (3) the groundwater storage variations (ΔGWS) show a negative trend estimated at −2.00±0.34 mm/year during the period April 2002–July 2017; and (4) the average annual precipitation (AAP) rate is estimated at 115 mm during the period 2002–2018. Three geoelectrical layers are identified from the inversion of the electrical resistivity data: (5) the surface layer of high resistivity values is consisted of dry unconsolidated Quaternary deposits; (6) the second layer represents the fractured groundwater aquifer of low resistivity values and variable thickness; (7) the third layer is composed of fractured basement rocks of higher resistivity values. The streams are draining the surface water toward the Najd Pedi plain aquifer; (8) the faults are acting as conduits for groundwater flow away from the Wadi. The current study indicates the occurrence of groundwater at the downstream zones of the Wadi Sar, but with a general decrease trend. The integrated approach provides a better understanding of the groundwater potentialities in the arid regions.
The North Western Sahara Aquifer System (NWSAS) is characterized by unsustainable groundwater exploitation whose magnitude depends on the still unclear recharge value. It is extending over Libya, Tunisia, and Algeria, with an area of 106 km2. Here, we proposed an integrated approach combining Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) data to reconstruct groundwater storage variations (ΔGWS) between April 2002 and July 2016. ΔGWS values are then introduced in a regional water budget equation accounting for the temporal evolution of withdrawals and natural discharge to calculate the time variations of the recharge. Yearly reconstruction of the recharge shows a large variability with alternation of net positive recharge and periods of net diffuse discharge associated with evaporation. The temporal average effective recharge value for the period of interest is 1.76 ± 0.44 mm yr−1. Lag-times for the recharge to reach the water table of 45 and 100 yrs characteristic of a diffuse recharge and corresponding vadose thickness in the range 3.90 ± 3.60 and 8.60 ± 8.10 m were identified using a cross-correlation analysis between reconstructed annual recharge and annual rainfall (AR). Statistical interpretation of the relation between ΔGWS, AR, and withdrawals shows that the anthropogenic effect (groundwater extraction) is the main controlling factor (99% of explained variance) in comparison to AR variations for the ΔGWS time series under consideration. A relation between long-term recharge and average annual rainfall (AAR) suggests a recharge representing 1.8 ± 0.3% of AAR in transboundary aquifers of the Saharan belt.
