Microwave‐Assisted Modification of Nanoalumina with Vitamin B3 as an Eco‐Friendly Nanosorbent for Trace Metals     

Mohamed E. Mahmoud  Amal R. Rashad  Shymaa H. Ragab  Tarek M. Abdel‐Fattah 《洁净——土壤、空气、水》2019,47(3)

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Sources of the predynastic grinding stones in the hu-semaineh region,upper Egypt,and their cultural context     

Abdel-Moneim A. Mahmoud  Kathryn A. Bard 《Geoarchaeology》1993,8(3):241-245

Grinding stones excavated at the Predynastic site of HG in Upper Egypt were analyzed, and consist of igneous rocks (rhyolite porphyry, basalt, granite) and metamorphic rocks (marble, quartzite). These rocks were brought to the site in Predynastic times (ca. 4000–3000 B. C.) from the Dokkan Volcanics located in the Wadi Hammamat, possibly as far away as 150 km. This is further evidence for the widespread exchange network that existed in Predynastic Upper Egypt. Complex economic interaction, as evidenced by artifacts excavated at HG, was a prime force as the early state evolved in Egypt. © 1993 John Wiley & Sons, Inc.  相似文献   

Hydrobiological variables as a regulatory factor on the abundance of heterotrophic flagellates in an urban pond     

BEGUM Moni  JEWEL Md.Abu Sayed  HAQUE Md.Ayenuddin  KHATUN Mst.Samsad 《海洋湖沼学报（英文）》2019,(3):1030-1036

The seasonal abundance of flagellates has been monitored over a period of 1 year from December 2013 to November 2014(divided into 4 conjugative seasons namely winter,spring,summer,and autumn)in an experimental pond located in Rajshahi City Corporation area,Bangladesh.To our knowledge,this study is the fi rst to shed light on the occurrence and possible interrelationships among heterotrophic flagellates(HF),bacteria and zooplankton in Bangladesh and the result obtained by this study will be beneficial for similar water ecosystem all over the world.Standard methods were used to determine the prescribed hydrological parameters and zooplankton cell density.Maximum HF abundance(14 346.00 cells/mL)was found in the spring and the minimum(5 215.00 cells/mL)occurred in the summer.Inverse to HF,significantly(P<0.05)higher zooplankton abundance was found during the winter(782.00±47.62 cells/mL)and the lowest value was found in the autumn(448.00±39.15 cells/mL).Whereas similar to the HF,total bacterial abundance was significantly higher during the spring((2.25±1.05)×10^5 cells/mL)and lower in the summer((0.79±0.06)×10^5 cells/mL).Multivariate analyses(ANOSIM and MDS)have shown significant seasonal differences for cell numbers where MDS ordination plot and cluster analysis based on similarity in the genera abundance of HF revealed overlapping condition between winter and spring.Canonical correspondence analysis(CCA)also showed a distinct separation among the genera based on the prevailing hydrological situation and indicated that temperature,pH,BOD5,and NO3^-were the most important environmental variables in determining the observed variation in HF community structure.Among the biological factors,zooplankton showed negative but total bacteria were positively correlated with HF abundance.  相似文献   

Magmatic and post-magmatic evolution of post-collisional rare-metal bearing granite: The Neoproterozoic Homrit Akarem Granitic Intrusion,south Eastern Desert of Egypt,Arabian-Nubian Shield     

Bassam A. Abuamarah  Mokhles K. Azer  Amany M.A. Seddik  Paul D. Asimow  Pedro Guzman  Brent T. Fultz  M.J. Wilner  Nathan Dalleska  Mahmoud H. Darwish 《Chemie der Erde / Geochemistry》2022,82(1):125840

The Homrit Akarem granitic intrusion (HAGI) outcrops near the western edge of the south Eastern Desert basement exposure in Egypt. It is a composite of two cogenetic intrusive bodies: an early albite granite phase shallowly emplaced at the apex of a magmatic cupola, and a later subjacent pink granite phase with a marginal zone of muscovite granite and better preservation of magmatic features. Mineral chemistry of primary biotite and garnet, together with whole-rock chemistry, identify the HAGI as a highly fractionated A-type peraluminous intrusion. The chemistry of F-dominant, Li-bearing, Fe³⁺-rich primary magmatic mica in the pink granite resembles that typically found in highly evolved Nb-Y-F pegmatites. The HAGI is the evolved product of a primary magma generated by partial melting of juvenile crust of the Arabian-Nubian Shield (ANS), emplaced along a regional strike-slip fault system that promoted its ascent. The main emplacement mechanism and evolutionary sequence of the HAGI was magmatic, although secondary minerals and textures resulting from hydrothermal fluid interactions are observed, especially at its margins. Primary columbite-(Mn) crystallized from melt and was partly replaced by secondary fluorcalciomicrolite. The high fluorine content of magmatic fluids exsolved from the intrusion is indicated by quartz-fluorite veins, greisenization, albitization, and F-bearing secondary oxide minerals. The magmatic derivation of this fluid is demonstrated by the F-dominant primary mica, a siderophyllite-polylithionite solid solution commonly known as zinnwaldite. The chemistry of zinnwaldite constrains the F/OH activity ratio and oxygen fugacity of its parental melt and thereby resolves the ambiguity between pressure and the effects of F in controlling the normative quartz content of rare-metal granites. The HAGI is less mineralized than the post-collisional rare-metal granites found further east in the south Eastern Desert, replicating a trend observed previously in the central Eastern Desert and suggesting that east-west zoning in rare metal enrichment is a persistent feature across latitudes at the western edge of the ANS.  相似文献   

Hydrogeochemical processes and multivariate analysis for groundwater quality in the arid Maadher region of Hodna,northern Algeria     

Selmane  Tahar  Dougha  Mostefa  Hasbaia  Mahmoud  Ferhati  Ahmed  Redjem  Ali 《中国地球化学学报》2022,41(5):893-909

Acta Geochimica - This study focused on water quality and hydro-geochemical processes (evolution, origin) in the Maadher region, central Hodna in Algeria. In recent decades, the excessive...  相似文献   

Post-cyclic Pullout Response of Geogrid in Compacted Sand and Clayey Sand with Emphasis on Pre-cyclic Load Effect     

Mahigir  Ali  Ardakani  Alireza  Hassanlourad  Mahmoud 《Geotechnical and Geological Engineering》2022,40(11):5565-5576

Geotechnical and Geological Engineering - Soil-geosynthetic interface behavior under cyclic loading will differ from that under static loading. To this end, a series of static and multistep tests...  相似文献   

Mapping Structurally Controlled Alterations Sparked by Hydrothermal Activity in the Fatira–Abu Zawal Area, Eastern Desert, Egypt     

Mohamed BADAWI  Mahmoud ABDELATIF  Ali SHEBL  Farid MAKROUM  Ahmed SHALABY  Norbert NEMETH 《《地质学报》英文版》2023,97(2):662-680

The Eastern Desert of Egypt suffered a protracted period of deformation triggered by cratonization of the new juvenile crust known as the Arabian Nubian Shield (ANS), which has been proposed for potential gold discoveries associated with the corresponding tectonic event. The Fatira area, on the border of Egypt''s Northern and Central Eastern Deserts, is covered with metavolcanic rocks twisted by a dextral relocation of the Fatira Shear Zone (FSZ) relative to the Barud magmatic body. The recent study evaluated many deformed post-orogenic granitic intrusions and felsite dikes associated with promising mineralization localities, notably orogenic gold deposits. The combination of various field observations and remote sensing data, followed by the analysis of aeromagnetic enhanced maps, allowed the differentiation of distinct lithologies, structural features, and hydrothermal alterations in the study area. Additionally, the integrated results obtained from the different interpretation techniques are utilized to identify and confirm the previously supposed mineralized localities in the Fatira and Abu Zawal areas and predict other matched localities. The final ASTER, Sentinel 2 hydrothermal alteration, and orientation entropy heat maps demonstrate the association between these mineralized regions and major structures related to the FSZ late stage of deformation rather than other structures studied throughout the area of interest.  相似文献   

Sequence stratigraphy and depositional environments of Late Cretaceous–Early Palaeogene succession,North Eastern Desert,Egypt     

Mohamed Youssef  Mahmoud Hefny 《Swiss Journal of Geoscience》2015,108(2-3):345-359

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Hydrogeochemical Processes Controlling the Water Chemistry of a Closed Saline Lake Located in Sahara Desert: Lake Qarun,Egypt   总被引：1，自引：0，他引：1  

Mahmoud S. M. Abdel Wahed  Essam A. Mohamed  Mohamed I. El-Sayed  Adel M’nif  Mika Sillanpää 《Aquatic Geochemistry》2015,21(1):31-57

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Environmental status and nutrients and dissolved organic carbon budget of two Saudi Arabian Red Sea coastal inlets: a snapshot statement     

Mohamed A. El Sayed  Radwan Kh. Al Farawati  Amr A. El Maradny  Yasser A. Shaban  Ahmed E. Rifaat 《Environmental Earth Sciences》2015,74(12):7755-7767

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