Integrating various tools in targeting mineral deposits increases the chance of adequate detectio... more Integrating various tools in targeting mineral deposits increases the chance of adequate detection and characterization of mineralization zones. Selecting a convenient dataset is a key for a precise geological and hydrothermal alteration mapping. Remote sensing and airborne geophysical data have proven their efficiency as tools for reliable mineral exploration. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced land imager (ALI), Landsat 8 (L8), and Sentinel 2 data are widely-used data among various types of remote sensing images in resolving lithological and hydrothermal alteration mapping over the last two decades. ASTER is a well-established satellite in geological remote sensing with detailed Short-wave infrared (SWIR) range compared to visible and near-infrared region (VNIR) that controls iron-associated alteration detection. On contrary, ALI has excellent coverage of the VNIR area (6 bands), but does not possess the potentiality of ASTER for the S...
... geochemistry. Authors: El Desouky, Hamdy Ahmed Batelaan, Okke Keppens, Eddy Eliwa, Hassan Daw... more ... geochemistry. Authors: El Desouky, Hamdy Ahmed Batelaan, Okke Keppens, Eddy Eliwa, Hassan Dawoud, Maher Al-Boghdady, Ahmed Hung, LQ. Issue Date: 2008. Publisher: Geological Society of South Africa - GSSA. Host ...
ABSTRACT The Wadi Watir delta, in the arid Sinai Peninsula, Egypt, contains an alluvial aquifer u... more ABSTRACT The Wadi Watir delta, in the arid Sinai Peninsula, Egypt, contains an alluvial aquifer underlain by impermeable Precambrian basement rock. The scarcity of rainfall during the last decade, combined with high pumping rates, resulted in degradation of water quality in the main supply wells along the mountain front, which has resulted in reduced groundwater pumping. Additionally, seawater intrusion along the coast has increased salinity in some wells. A three-dimensional (3D) groundwater flow model (MODFLOW) was calibrated using groundwater-level changes and pumping rates from 1982 to 2009; the groundwater recharge rate was estimated to be 1.58 × 106 m3/year. A variable-density flow model (SEAWAT) was used to evaluate seawater intrusion for different pumping rates and well-field locations. Water chemistry and stable isotope data were used to calculate seawater mixing with groundwater along the coast. Geochemical modeling (NETPATH) determined the sources and mixing of different groundwaters from the mountainous recharge areas and within the delta aquifers; results showed that the groundwater salinity is controlled by dissolution of minerals and salts in the aquifers along flow paths and mixing of chemically different waters, including upwelling of saline groundwater and seawater intrusion. Future groundwater pumping must be closely monitored to limit these effects.
Doping ZnO with different ratios of clays can increase the value of nonlinear parameters. The nat... more Doping ZnO with different ratios of clays can increase the value of nonlinear parameters. The natural clay has been precipitated in water column, as a result of the difference in the physical properties of the different phases, the clay will precipitate in layers lighter by lighter from the bottom of the water column, So SiO2 concentrates in lower layers and decreases to the upper layers, whereas Albite, montomorillonite, and dolomite behaves in opposite.ZnO has been doped with different layers up to 20 % clay and sintered at 1200 C for one hour. The obtained samples have been prepared for the different measurements XRD, J-E characteristics, and SEM. XRD showed different phases with different percentages along the whole divided layers of the precipitated column. The maximum value of SiO2 concentrates at layer 3 while the other phases have their lowest values. The electrical measurements (J-E) declared that the maximum value of α obtained by dope ZnO with layer 7 or layer no.11. The ...
The El-Dabbah Group of the Nubian Shield, Central Eastern Desert, Egypt, contains a Neoproterozoi... more The El-Dabbah Group of the Nubian Shield, Central Eastern Desert, Egypt, contains a Neoproterozoic banded iron sequence within volcaniclastic rocks deposited in an island arc setting. The group contains a volcaniclastic sequence of relatively undeformed lower-greenschist-facies rocks that are unconformably overlain by terrestrial sedimentary strata of the Hamamat Group. The group is > 7000 m thick and contains three formations (the Lower, Middle, and Upper El-Dabbah formations), which include massive metavolcanic rocks, pillow lavas, well-bedded volcaniclastic rocks, black and greenish shale and banded iron sequences. There is no evidence of glaciation, such as diamictites or cap-carbonate beds, in the three formations. The Middle El-Dabbah Formation (2000 m thick) contains well-preserved iron sequences within the volcaniclastic rocks. Most of the iron sequences comprise beds that are a few meters thick. The iron sequence rocks have low contents of Al, Ti, K, and Na, and low Al/(...
Abstract Stabilization of hazardous wastes produced as a result of water purification or decontam... more Abstract Stabilization of hazardous wastes produced as a result of water purification or decontamination of radioactive or toxic liquids by using traditional or novel strategies like the promising biological remediation through phytoremediation and biomass adsorption is of utmost importance. The dried plants of Myriophyllum spicatum L was immobilized by using commercial cement as described in this study. The optimal amount of embedded dried plant waste was found to be 8% relative to cement; this solidified waste composite had a compressive strength of over 10 MPa. Mechanical, physical and chemical stabilities of the immobilized waste were evaluated through the impact of frost and water flooding by measuring the mechanical and chemical integrities associated with spectroscopic and scanning analyses. In both conditions, a negligible deterioration of mechanical integrity or morphological appearance of examined samples was detected after 90-day exposure comparing with control sample. Furthermore, chemical stability was evaluated by introducing other solidified samples contaminated with 137Cs to drastic event of flooding in various aqueous media and different surrounding temperatures with other environmental conditions. Hence, cement-dried waste composite has attained mechanical and chemical stability under flooding and freezing events.
Abstract The El-Dabbah Group is a >7500 m-thick sequence of metavolcanic rocks, volcaniclastic... more Abstract The El-Dabbah Group is a >7500 m-thick sequence of metavolcanic rocks, volcaniclastics, and banded iron-formation located within the Nubian Shield, Central Eastern Desert, Egypt. The sequence preserves lower greenschist-facies island arc rocks. We used detailed mapping to reconstruct the stratigraphic and tectonic history of the El-Dabbah Group and the surrounding sedimentary basins. The El-Dabbah Group was identified as deposition at central rift zone of an oceanic island arc and was overlies by the subaerial sedimentary rocks (the Atshan Formation and the Hammamat Group). Four faulting were distinguished within the El-Dabbah area: (1) top-to-the-S low-angle thrusting; (2) NNE side down normal faulting; (3) sinistral displacement on north–south faults; and (4) WNE trend N-side-down normal faulting with the Hammamat Group. We obtained the crystallization ages of a granite (638.1 ± 2.9 Ma) and a quartz porphyry (659.6 ± 3.0 Ma). The detrital zircon age of the Hammamat Group show peaks at 650, 680, and 790 Ma. These evidences suggest, three sedimentation-deformation stages were identified in this area. Stage 1 involved sedimentation of island-arc-derived volcaniclastic rocks at 770-700 Ma and to thrust related accretion at 700–680 Ma. Stage 2 involved collisional and transtensional deformation related to formation of the subaerial basin that contains the Atshan Formation at 670-640 Ma, the normal fault, the strike-slip fault and granite intrusion during 660–620 Ma. Stage 3 involved orogenic collapse, regional strike-slip-related sedimentation and deformation of the Hammamat Group at 610–570 Ma. We show that the El-Dabbah Group records a history of oceanic island arc accretion, collision, and collapse within the northern East African Orogeny during 770–570 Ma in Neoproterozoic.
Abstract Modern technological routes of decontamination of polluted environments are expected to ... more Abstract Modern technological routes of decontamination of polluted environments are expected to outperform traditional strategies. Such routes have been perceived as more efficient and/or less expensive, and, most of all, as environmentally friendly. In this context, submerged plants without any agricultural use are considered new and intriguing alternatives in the current search for more sustainable remediation of toxic and radioactive wastewater. Myriophyllum spicatum (Eurasian watermilfoil), a submerged aquatic plant present in fresh water streams, is considered a threat for aquatic environment. In present research, this plant was utilized for decontamination of simulated wastewater spiked with both radioactive and non-radioactive cobalt and cesium isotopes. Several parameters were evaluated to optimize the phytoremediation of these elements, such as the pH-value of the contaminated medium, illumination, contact time, ion competition, concentration of dissolved elements, mass of plant, and content of radioactive material. More than 90% and 60% of stable cobalt and cesium, respectively, were eliminated at optimal conditions of contact time with higher pH-value, light, and optimum mass of applied biomass. The same elimination values were achieved also in case of using radioisotopes of the same elements. The study demonstrates that Myriophyllum spicatum can be used as a promising candidate for phytoremediation of cobalt and cesium even if present as radioisotopes from contaminated aqueous media, thus being a green alternative for traditional remediation technologies.
Abstract The Quaternary coastal plain aquifer down gradient of the Wadi Watir catchment is the ma... more Abstract The Quaternary coastal plain aquifer down gradient of the Wadi Watir catchment is the main source of potable groundwater in the arid region of south Sinai, Egypt. The scarcity of rainfall over the last decade, combined with high groundwater pumping rates, have resulted in water-quality degradation in the main well field and in wells along the coast. Understanding the sources of groundwater salinization and amount of average annual recharge is critical for developing sustainable groundwater management strategies for the long-term prevention of groundwater quality deterioration. A combination of geochemistry, conservative ions (Cl and Br), and isotopic tracers ( 87/86 Sr, δ 81 Br, δ 37 Cl), in conjunction with groundwater modeling, is an effective method to assess and manage groundwater resources in the Wadi Watir delta aquifers. High groundwater salinity, including high Cl and Br concentrations, is recorded inland in the deep drilled wells located in the main well field and in wells along the coast. The range of Cl/Br ratios for shallow and deep groundwaters in the delta (∼50–97) fall between the end member values of the recharge water that comes from the up gradient watershed, and evaporated seawater of marine origin, which is significantly different than the ratio in modern seawater (228). The 87/86 Sr and δ 81 Br isotopic values were higher in the recharge water (0.70,723 87/86 Sr 81 Br 87/86 Sr 81 Br 37 Cl isotopic values were lower in the recharge water (−0.48 37 Cl 37 Cl A three-dimensional, variable-density, flow-and-transport SEAWAT model was developed using groundwater isotopes ( 87 Sr/ 86 Sr, δ 37 Cl and δ 81 Br) and calibrated using historical records of groundwater level and salinity. δ 18 O was used to normalize the evaporative effect on shallow groundwater salinity for model calibration. The model shows how groundwater salinity and hydrologic data can be used in SEAWAT to understand recharge mechanisms, estimate groundwater recharge rates, and simulate the upwelling of deep saline groundwater and seawater intrusion. The model indicates that most of the groundwater recharge occurs near the outlet of the main channel. Average annual recharge to delta alluvial aquifers for 1982 to 2009 is estimated to be 2.16 × 10 6 m 3 /yr. The main factors that control groundwater salinity are overpumping and recharge availability.
Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of... more Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of the Eastern Desert of Egypt. They are a suite of basaltic andesite and andesite mafic dykes, and dacitic and rhyolitic felsic dykes. The mafic dyke suite is more abundant in the younger granites (577 ± 6 Ma) than in the older granitoids (614 Ma), in which the felsic dykes are the most common. The dyke swarms trend predominantly NE–SW, and the felsic dyke suite is older than the mafic dyke suite. Both dyke suites are calc-alkaline (alkaline dykes are rare) and are relatively poor in TiO2 and Nb but enriched in the incompatible elements and HFSE. The felsic dyke suite is enriched in REE and is strongly LREE fractionated relative to the mafic dyke suite. Although the Hawashiya dykes were emplaced at the end of the Neoproterozoic era in an extensional tectonic setting, they have geochemical characteristics that are consistent with a subduction-related regime. These chemical signatures were ...
Doping ZnO with different ratios of modulatedclays increases the value of nonlinear parameters. N... more Doping ZnO with different ratios of modulatedclays increases the value of nonlinear parameters. Nutural Clays are mixed of oxides with different concentration.Raw clay has been precipitated in the water column, as a result of the difference in the physical properties of the excisting phases,the clay will precipitate in layers lighter by lighter from the bottom of the water column. SiO 2 concentrates in lower layers and decreases to the upper layers, whereas Albite, montmorillonite, and dolomite behave in the opposite manner.XRD showed different phases with different percentages along the whole divided layers of the precipitated column. The maximum value of SiO 2 concentrates at layer 3 while the other phases have lower values. ZnO varistor has been prepared by doping with different layers up to 20 % preciptated clays and sintered C for one hour. The obtained samples investigated by different measurements XRD, J-E characteristics, and SEM. The electrical measurements (J-E) declared t...
Integrating various tools in targeting mineral deposits increases the chance of adequate detectio... more Integrating various tools in targeting mineral deposits increases the chance of adequate detection and characterization of mineralization zones. Selecting a convenient dataset is a key for a precise geological and hydrothermal alteration mapping. Remote sensing and airborne geophysical data have proven their efficiency as tools for reliable mineral exploration. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced land imager (ALI), Landsat 8 (L8), and Sentinel 2 data are widely-used data among various types of remote sensing images in resolving lithological and hydrothermal alteration mapping over the last two decades. ASTER is a well-established satellite in geological remote sensing with detailed Short-wave infrared (SWIR) range compared to visible and near-infrared region (VNIR) that controls iron-associated alteration detection. On contrary, ALI has excellent coverage of the VNIR area (6 bands), but does not possess the potentiality of ASTER for the S...
... geochemistry. Authors: El Desouky, Hamdy Ahmed Batelaan, Okke Keppens, Eddy Eliwa, Hassan Daw... more ... geochemistry. Authors: El Desouky, Hamdy Ahmed Batelaan, Okke Keppens, Eddy Eliwa, Hassan Dawoud, Maher Al-Boghdady, Ahmed Hung, LQ. Issue Date: 2008. Publisher: Geological Society of South Africa - GSSA. Host ...
ABSTRACT The Wadi Watir delta, in the arid Sinai Peninsula, Egypt, contains an alluvial aquifer u... more ABSTRACT The Wadi Watir delta, in the arid Sinai Peninsula, Egypt, contains an alluvial aquifer underlain by impermeable Precambrian basement rock. The scarcity of rainfall during the last decade, combined with high pumping rates, resulted in degradation of water quality in the main supply wells along the mountain front, which has resulted in reduced groundwater pumping. Additionally, seawater intrusion along the coast has increased salinity in some wells. A three-dimensional (3D) groundwater flow model (MODFLOW) was calibrated using groundwater-level changes and pumping rates from 1982 to 2009; the groundwater recharge rate was estimated to be 1.58 × 106 m3/year. A variable-density flow model (SEAWAT) was used to evaluate seawater intrusion for different pumping rates and well-field locations. Water chemistry and stable isotope data were used to calculate seawater mixing with groundwater along the coast. Geochemical modeling (NETPATH) determined the sources and mixing of different groundwaters from the mountainous recharge areas and within the delta aquifers; results showed that the groundwater salinity is controlled by dissolution of minerals and salts in the aquifers along flow paths and mixing of chemically different waters, including upwelling of saline groundwater and seawater intrusion. Future groundwater pumping must be closely monitored to limit these effects.
Doping ZnO with different ratios of clays can increase the value of nonlinear parameters. The nat... more Doping ZnO with different ratios of clays can increase the value of nonlinear parameters. The natural clay has been precipitated in water column, as a result of the difference in the physical properties of the different phases, the clay will precipitate in layers lighter by lighter from the bottom of the water column, So SiO2 concentrates in lower layers and decreases to the upper layers, whereas Albite, montomorillonite, and dolomite behaves in opposite.ZnO has been doped with different layers up to 20 % clay and sintered at 1200 C for one hour. The obtained samples have been prepared for the different measurements XRD, J-E characteristics, and SEM. XRD showed different phases with different percentages along the whole divided layers of the precipitated column. The maximum value of SiO2 concentrates at layer 3 while the other phases have their lowest values. The electrical measurements (J-E) declared that the maximum value of α obtained by dope ZnO with layer 7 or layer no.11. The ...
The El-Dabbah Group of the Nubian Shield, Central Eastern Desert, Egypt, contains a Neoproterozoi... more The El-Dabbah Group of the Nubian Shield, Central Eastern Desert, Egypt, contains a Neoproterozoic banded iron sequence within volcaniclastic rocks deposited in an island arc setting. The group contains a volcaniclastic sequence of relatively undeformed lower-greenschist-facies rocks that are unconformably overlain by terrestrial sedimentary strata of the Hamamat Group. The group is > 7000 m thick and contains three formations (the Lower, Middle, and Upper El-Dabbah formations), which include massive metavolcanic rocks, pillow lavas, well-bedded volcaniclastic rocks, black and greenish shale and banded iron sequences. There is no evidence of glaciation, such as diamictites or cap-carbonate beds, in the three formations. The Middle El-Dabbah Formation (2000 m thick) contains well-preserved iron sequences within the volcaniclastic rocks. Most of the iron sequences comprise beds that are a few meters thick. The iron sequence rocks have low contents of Al, Ti, K, and Na, and low Al/(...
Abstract Stabilization of hazardous wastes produced as a result of water purification or decontam... more Abstract Stabilization of hazardous wastes produced as a result of water purification or decontamination of radioactive or toxic liquids by using traditional or novel strategies like the promising biological remediation through phytoremediation and biomass adsorption is of utmost importance. The dried plants of Myriophyllum spicatum L was immobilized by using commercial cement as described in this study. The optimal amount of embedded dried plant waste was found to be 8% relative to cement; this solidified waste composite had a compressive strength of over 10 MPa. Mechanical, physical and chemical stabilities of the immobilized waste were evaluated through the impact of frost and water flooding by measuring the mechanical and chemical integrities associated with spectroscopic and scanning analyses. In both conditions, a negligible deterioration of mechanical integrity or morphological appearance of examined samples was detected after 90-day exposure comparing with control sample. Furthermore, chemical stability was evaluated by introducing other solidified samples contaminated with 137Cs to drastic event of flooding in various aqueous media and different surrounding temperatures with other environmental conditions. Hence, cement-dried waste composite has attained mechanical and chemical stability under flooding and freezing events.
Abstract The El-Dabbah Group is a >7500 m-thick sequence of metavolcanic rocks, volcaniclastic... more Abstract The El-Dabbah Group is a >7500 m-thick sequence of metavolcanic rocks, volcaniclastics, and banded iron-formation located within the Nubian Shield, Central Eastern Desert, Egypt. The sequence preserves lower greenschist-facies island arc rocks. We used detailed mapping to reconstruct the stratigraphic and tectonic history of the El-Dabbah Group and the surrounding sedimentary basins. The El-Dabbah Group was identified as deposition at central rift zone of an oceanic island arc and was overlies by the subaerial sedimentary rocks (the Atshan Formation and the Hammamat Group). Four faulting were distinguished within the El-Dabbah area: (1) top-to-the-S low-angle thrusting; (2) NNE side down normal faulting; (3) sinistral displacement on north–south faults; and (4) WNE trend N-side-down normal faulting with the Hammamat Group. We obtained the crystallization ages of a granite (638.1 ± 2.9 Ma) and a quartz porphyry (659.6 ± 3.0 Ma). The detrital zircon age of the Hammamat Group show peaks at 650, 680, and 790 Ma. These evidences suggest, three sedimentation-deformation stages were identified in this area. Stage 1 involved sedimentation of island-arc-derived volcaniclastic rocks at 770-700 Ma and to thrust related accretion at 700–680 Ma. Stage 2 involved collisional and transtensional deformation related to formation of the subaerial basin that contains the Atshan Formation at 670-640 Ma, the normal fault, the strike-slip fault and granite intrusion during 660–620 Ma. Stage 3 involved orogenic collapse, regional strike-slip-related sedimentation and deformation of the Hammamat Group at 610–570 Ma. We show that the El-Dabbah Group records a history of oceanic island arc accretion, collision, and collapse within the northern East African Orogeny during 770–570 Ma in Neoproterozoic.
Abstract Modern technological routes of decontamination of polluted environments are expected to ... more Abstract Modern technological routes of decontamination of polluted environments are expected to outperform traditional strategies. Such routes have been perceived as more efficient and/or less expensive, and, most of all, as environmentally friendly. In this context, submerged plants without any agricultural use are considered new and intriguing alternatives in the current search for more sustainable remediation of toxic and radioactive wastewater. Myriophyllum spicatum (Eurasian watermilfoil), a submerged aquatic plant present in fresh water streams, is considered a threat for aquatic environment. In present research, this plant was utilized for decontamination of simulated wastewater spiked with both radioactive and non-radioactive cobalt and cesium isotopes. Several parameters were evaluated to optimize the phytoremediation of these elements, such as the pH-value of the contaminated medium, illumination, contact time, ion competition, concentration of dissolved elements, mass of plant, and content of radioactive material. More than 90% and 60% of stable cobalt and cesium, respectively, were eliminated at optimal conditions of contact time with higher pH-value, light, and optimum mass of applied biomass. The same elimination values were achieved also in case of using radioisotopes of the same elements. The study demonstrates that Myriophyllum spicatum can be used as a promising candidate for phytoremediation of cobalt and cesium even if present as radioisotopes from contaminated aqueous media, thus being a green alternative for traditional remediation technologies.
Abstract The Quaternary coastal plain aquifer down gradient of the Wadi Watir catchment is the ma... more Abstract The Quaternary coastal plain aquifer down gradient of the Wadi Watir catchment is the main source of potable groundwater in the arid region of south Sinai, Egypt. The scarcity of rainfall over the last decade, combined with high groundwater pumping rates, have resulted in water-quality degradation in the main well field and in wells along the coast. Understanding the sources of groundwater salinization and amount of average annual recharge is critical for developing sustainable groundwater management strategies for the long-term prevention of groundwater quality deterioration. A combination of geochemistry, conservative ions (Cl and Br), and isotopic tracers ( 87/86 Sr, δ 81 Br, δ 37 Cl), in conjunction with groundwater modeling, is an effective method to assess and manage groundwater resources in the Wadi Watir delta aquifers. High groundwater salinity, including high Cl and Br concentrations, is recorded inland in the deep drilled wells located in the main well field and in wells along the coast. The range of Cl/Br ratios for shallow and deep groundwaters in the delta (∼50–97) fall between the end member values of the recharge water that comes from the up gradient watershed, and evaporated seawater of marine origin, which is significantly different than the ratio in modern seawater (228). The 87/86 Sr and δ 81 Br isotopic values were higher in the recharge water (0.70,723 87/86 Sr 81 Br 87/86 Sr 81 Br 37 Cl isotopic values were lower in the recharge water (−0.48 37 Cl 37 Cl A three-dimensional, variable-density, flow-and-transport SEAWAT model was developed using groundwater isotopes ( 87 Sr/ 86 Sr, δ 37 Cl and δ 81 Br) and calibrated using historical records of groundwater level and salinity. δ 18 O was used to normalize the evaporative effect on shallow groundwater salinity for model calibration. The model shows how groundwater salinity and hydrologic data can be used in SEAWAT to understand recharge mechanisms, estimate groundwater recharge rates, and simulate the upwelling of deep saline groundwater and seawater intrusion. The model indicates that most of the groundwater recharge occurs near the outlet of the main channel. Average annual recharge to delta alluvial aquifers for 1982 to 2009 is estimated to be 2.16 × 10 6 m 3 /yr. The main factors that control groundwater salinity are overpumping and recharge availability.
Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of... more Dyke swarms traverse Neoproterozoic rocks in the Hawashiya region in the extreme northern part of the Eastern Desert of Egypt. They are a suite of basaltic andesite and andesite mafic dykes, and dacitic and rhyolitic felsic dykes. The mafic dyke suite is more abundant in the younger granites (577 ± 6 Ma) than in the older granitoids (614 Ma), in which the felsic dykes are the most common. The dyke swarms trend predominantly NE–SW, and the felsic dyke suite is older than the mafic dyke suite. Both dyke suites are calc-alkaline (alkaline dykes are rare) and are relatively poor in TiO2 and Nb but enriched in the incompatible elements and HFSE. The felsic dyke suite is enriched in REE and is strongly LREE fractionated relative to the mafic dyke suite. Although the Hawashiya dykes were emplaced at the end of the Neoproterozoic era in an extensional tectonic setting, they have geochemical characteristics that are consistent with a subduction-related regime. These chemical signatures were ...
Doping ZnO with different ratios of modulatedclays increases the value of nonlinear parameters. N... more Doping ZnO with different ratios of modulatedclays increases the value of nonlinear parameters. Nutural Clays are mixed of oxides with different concentration.Raw clay has been precipitated in the water column, as a result of the difference in the physical properties of the excisting phases,the clay will precipitate in layers lighter by lighter from the bottom of the water column. SiO 2 concentrates in lower layers and decreases to the upper layers, whereas Albite, montmorillonite, and dolomite behave in the opposite manner.XRD showed different phases with different percentages along the whole divided layers of the precipitated column. The maximum value of SiO 2 concentrates at layer 3 while the other phases have lower values. ZnO varistor has been prepared by doping with different layers up to 20 % preciptated clays and sintered C for one hour. The obtained samples investigated by different measurements XRD, J-E characteristics, and SEM. The electrical measurements (J-E) declared t...
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