Pub Date : 2020-06-24DOI: 10.1080/20909977.2020.1853012
Y. A. Azzam, M. Nouh, A. Shaker
ABSTRACT Innovation in the ground and space-based instruments has taken us into a new age of spectroscopy, in which a large amount of stellar content is becoming available. So, automatic classification of stellar spectra became subjective in the last three decades due to the availability of large observed spectral database as well as the theoretical spectra. In the present paper, we develop an Artificial Neural Network (ANN) algorithm for automated classification of stellar spectra. The algorithm has been applied to extract the fundamental parameters of the optical spectra of some hot helium-rich white dwarf stars observed by the Sloan Digital Sky Survey (SDSS) and B-type spectra observed at Onderjove observatory. We compared the present fundamental parameters and those from a minimum distance method to clarify the accuracy of the present algorithm where we found that the predicted atmospheric parameters for the two samples are in good agreement for about 50% of the samples. A possible explanation for the discrepancies found for the rest of the samples is discussed.
{"title":"Prediction of the atmospheric fundamental parameters from stellar spectra using artificial neural network","authors":"Y. A. Azzam, M. Nouh, A. Shaker","doi":"10.1080/20909977.2020.1853012","DOIUrl":"https://doi.org/10.1080/20909977.2020.1853012","url":null,"abstract":"ABSTRACT Innovation in the ground and space-based instruments has taken us into a new age of spectroscopy, in which a large amount of stellar content is becoming available. So, automatic classification of stellar spectra became subjective in the last three decades due to the availability of large observed spectral database as well as the theoretical spectra. In the present paper, we develop an Artificial Neural Network (ANN) algorithm for automated classification of stellar spectra. The algorithm has been applied to extract the fundamental parameters of the optical spectra of some hot helium-rich white dwarf stars observed by the Sloan Digital Sky Survey (SDSS) and B-type spectra observed at Onderjove observatory. We compared the present fundamental parameters and those from a minimum distance method to clarify the accuracy of the present algorithm where we found that the predicted atmospheric parameters for the two samples are in good agreement for about 50% of the samples. A possible explanation for the discrepancies found for the rest of the samples is discussed.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"17 1","pages":"23 - 34"},"PeriodicalIF":0.0,"publicationDate":"2020-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90217681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1734999
K. Gemail, S. Shebl, M. Attwa, S. Soliman, A. Azab, M. H. Farag
ABSTRACT The new urban development is an important priority in Egypt to face a rapid increase in the population during the last few decades. As a case study, the geotechnical assessment of the New Minia City is studied applying direct current (DC) resistivity technique. In the presented study, the DC resistivity data are interpreted to (i) characterize the subsurface layer distributions, (ii) deduce the subsurface structures considering the surface geological and structural setting and borehole information and (iii) predict geotechnical parameters of the bedrock based on empirical relationships. The inversion results of DC resistivity data indicate that a lens of clay is locally capping the fractured limestone in different parts of the area. The constructed geoelectrical cross-sections show that the limestone bedrock is highly fractured regarding many normal faults trending in the NW and NE directions. In an attempt to derive empirical relationships for predicting the geotechnical parameters, the inverted resistivity values of the fractured limestone were correlated with different geotechnical parameters, Rock Quality Designation (RQD) and Unconfined Compressive Strength (UCS). It is noticed that there are good correlations between the limestone resistivity values and geotechnical parameters obtained from borehole data applying linear relations. Accordingly, the results indicate that the DC resistivity method constitutes a valuable technique to introduce a preliminary geotechnical assessment for new urban areas.
{"title":"Geotechnical assessment of fractured limestone bedrock using DC resistivity method: a case study at New Minia City, Egypt","authors":"K. Gemail, S. Shebl, M. Attwa, S. Soliman, A. Azab, M. H. Farag","doi":"10.1080/20909977.2020.1734999","DOIUrl":"https://doi.org/10.1080/20909977.2020.1734999","url":null,"abstract":"ABSTRACT The new urban development is an important priority in Egypt to face a rapid increase in the population during the last few decades. As a case study, the geotechnical assessment of the New Minia City is studied applying direct current (DC) resistivity technique. In the presented study, the DC resistivity data are interpreted to (i) characterize the subsurface layer distributions, (ii) deduce the subsurface structures considering the surface geological and structural setting and borehole information and (iii) predict geotechnical parameters of the bedrock based on empirical relationships. The inversion results of DC resistivity data indicate that a lens of clay is locally capping the fractured limestone in different parts of the area. The constructed geoelectrical cross-sections show that the limestone bedrock is highly fractured regarding many normal faults trending in the NW and NE directions. In an attempt to derive empirical relationships for predicting the geotechnical parameters, the inverted resistivity values of the fractured limestone were correlated with different geotechnical parameters, Rock Quality Designation (RQD) and Unconfined Compressive Strength (UCS). It is noticed that there are good correlations between the limestone resistivity values and geotechnical parameters obtained from borehole data applying linear relations. Accordingly, the results indicate that the DC resistivity method constitutes a valuable technique to introduce a preliminary geotechnical assessment for new urban areas.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"74 1","pages":"272 - 279"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85596500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1722524
Ahmad Nabi, Xiao-dong Liu, Z. Gong, Abbas R. Ali
ABSTRACT Electric resistivity tomography (ERT) is applied across active concealed faults to confirm the subsurface manifestation and lateral extension of capable faults in Karachi Arc, southern Kirthar Fold Belt, Pakistan. During palaeoseismological investigations, active faults and movements along them are identified using electrical resistivity imaging and trenching. The electrical resistivity images present the general structure of the investigated area, with the possibility of tracking the fault in the subsurface. The verification of faults and comparison of ERT profiles with the excavated trench logs confirmed the success of ERT. The results of ERT and trenching in three major parts of Karachi Arc show: (i) the southern inner part of the arc was inactive in Late Quaternary time, where the Sona Fault did not experience any recent movement; (ii) Kirthar and Khud faults in the northwestern part of the study area are active but do not extend into the southern Karachi Arc; and (iii) the frontal part of Karachi Arc is characterised by Quaternary faulting of limited strike length with a moderate rate of seismic activity. Based on the Karachi Arc case studies, ERT is found to be a reliable geophysical technique for studying near-surface geological structures, subsurface lithological mapping and fault characterisation.
{"title":"Electrical resistivity imaging of active faults in palaeoseismology: case studies from Karachi Arc, southern Kirthar Fold Belt, Pakistan","authors":"Ahmad Nabi, Xiao-dong Liu, Z. Gong, Abbas R. Ali","doi":"10.1080/20909977.2020.1722524","DOIUrl":"https://doi.org/10.1080/20909977.2020.1722524","url":null,"abstract":"ABSTRACT Electric resistivity tomography (ERT) is applied across active concealed faults to confirm the subsurface manifestation and lateral extension of capable faults in Karachi Arc, southern Kirthar Fold Belt, Pakistan. During palaeoseismological investigations, active faults and movements along them are identified using electrical resistivity imaging and trenching. The electrical resistivity images present the general structure of the investigated area, with the possibility of tracking the fault in the subsurface. The verification of faults and comparison of ERT profiles with the excavated trench logs confirmed the success of ERT. The results of ERT and trenching in three major parts of Karachi Arc show: (i) the southern inner part of the arc was inactive in Late Quaternary time, where the Sona Fault did not experience any recent movement; (ii) Kirthar and Khud faults in the northwestern part of the study area are active but do not extend into the southern Karachi Arc; and (iii) the frontal part of Karachi Arc is characterised by Quaternary faulting of limited strike length with a moderate rate of seismic activity. Based on the Karachi Arc case studies, ERT is found to be a reliable geophysical technique for studying near-surface geological structures, subsurface lithological mapping and fault characterisation.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"21 1","pages":"116 - 128"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78314710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1820267
R. Eid, M. El-Anbaawy, A. Abdelhalim
ABSTRACT The Nile Delta gas reservoirs are dominated by Plio-Pleistocene and Miocene channel deposits which became nowadays the key player for gas production in Egypt. These channelized features are spectacularly imaged on high-quality seismic data, this paper deals with channel geomorphology imaging using different geophysical and geological tools for better under-standing its architecture and fairway delineation in Sienna field also delineating some reasons for reservoir compartmentalization in the studied area which acts as an analogue for the marine slope channels in Pliocene reservoirs within West Delta deep marine concession (WDDM).Seismic attributes were used like Root Mean Square (RMS) amplitude extraction, Ant tracking and Spectral decomposition and finally pre-stack seismic inversion products. By correlating seismic signature with wells log data, four depositional cycles in the Sienna channel were identified which are stacked upon each other in Sienna canyon. The reason for Sienna system compartmentalization maybe not only effect by faults density but also facies quality which is changes from well to another as a result of distal deposits of turbidity slope channels. The location of new wells could be more precisely delineated for further reservoir development in Sienna channels.
{"title":"Integrated seismic and well gamma-ray analysis for delineation Sienna channel depositional architecture, offshore West Nile Delta, Egypt","authors":"R. Eid, M. El-Anbaawy, A. Abdelhalim","doi":"10.1080/20909977.2020.1820267","DOIUrl":"https://doi.org/10.1080/20909977.2020.1820267","url":null,"abstract":"ABSTRACT The Nile Delta gas reservoirs are dominated by Plio-Pleistocene and Miocene channel deposits which became nowadays the key player for gas production in Egypt. These channelized features are spectacularly imaged on high-quality seismic data, this paper deals with channel geomorphology imaging using different geophysical and geological tools for better under-standing its architecture and fairway delineation in Sienna field also delineating some reasons for reservoir compartmentalization in the studied area which acts as an analogue for the marine slope channels in Pliocene reservoirs within West Delta deep marine concession (WDDM).Seismic attributes were used like Root Mean Square (RMS) amplitude extraction, Ant tracking and Spectral decomposition and finally pre-stack seismic inversion products. By correlating seismic signature with wells log data, four depositional cycles in the Sienna channel were identified which are stacked upon each other in Sienna canyon. The reason for Sienna system compartmentalization maybe not only effect by faults density but also facies quality which is changes from well to another as a result of distal deposits of turbidity slope channels. The location of new wells could be more precisely delineated for further reservoir development in Sienna channels.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"121 1","pages":"563 - 571"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81784341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1746892
N. Bailek, K. Bouchouicha, Y. Abdel-Hadi, M. EL-Shimy, Abdeldjalil Slimani, B. Jamil, Abdallah Djaafari
ABSTRACT Global solar radiation data is essential in the design of solar energy conversion devices. The most widely used model in the estimation of the global solar radiation coming to the earth’s surface is the Angtröm-Prescott model. In this model, relative sunshine duration plays an important role. In the current study, it was attempted to review different models and to determine the best performing model developed for the city of Bechar and two locations of Algerian Big South desert for solar energy projects and compare them with the different established models available in the literature up until now, based on measured sunshine hours data. The new models give high accuracies on the application, where (R2) ranges between 0.70 and 0.99. In addition, MBE and RMSE values are very low in the studied stations. The results presented in this paper are quite useful for quick estimation of global solar radiation data required for performance evaluation of solar collector used for different applications of solar energy.
{"title":"Developing a new model for predicting global solar radiation on a horizontal surface located in Southwest Region of Algeria","authors":"N. Bailek, K. Bouchouicha, Y. Abdel-Hadi, M. EL-Shimy, Abdeldjalil Slimani, B. Jamil, Abdallah Djaafari","doi":"10.1080/20909977.2020.1746892","DOIUrl":"https://doi.org/10.1080/20909977.2020.1746892","url":null,"abstract":"ABSTRACT Global solar radiation data is essential in the design of solar energy conversion devices. The most widely used model in the estimation of the global solar radiation coming to the earth’s surface is the Angtröm-Prescott model. In this model, relative sunshine duration plays an important role. In the current study, it was attempted to review different models and to determine the best performing model developed for the city of Bechar and two locations of Algerian Big South desert for solar energy projects and compare them with the different established models available in the literature up until now, based on measured sunshine hours data. The new models give high accuracies on the application, where (R2) ranges between 0.70 and 0.99. In addition, MBE and RMSE values are very low in the studied stations. The results presented in this paper are quite useful for quick estimation of global solar radiation data required for performance evaluation of solar collector used for different applications of solar energy.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"1 1","pages":"341 - 349"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86446796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1732571
A. D Adebiyi, K. Adiat, A. B Eluwole
ABSTRACT Soil electrical resistivity measurements and soil properties determination were carried out at an arable plot located within the Federal University of Technology, Akure, Ondo State. This was with a view to establishing relationship between in-situ soil resistivity and selected topsoil properties in a typical basement complex environment. Electrical Resistivity was measured from the soil surface at 0 to 50 cm soil depths using Wenner Array. Electrode spacing of 130 cm (1.3 m) was utilized. Soil samples were collected to a depth of 50 cm at the mid points of 2 m by 2 m cell. These were analyzed for properties that include: moisture content, particle size analysis, Organic Matter (OM), pH and electrical conductivity. The regression analysis plots show that ER correlate significantly to soil properties, with coefficient of correlation of 0.90 for MC, 0.63 for SC, 0.74 for CC, 0.57 for OM, 0.94 for EC. Except for SC and PH that shows a non-significant correlation of 0.52 and 0.30 respectively. Validation of the derived empirical model gives a coefficient of correlation between the observed and predicted result as 0.94 for MC, 0.74 for OM, 0.93 for EC, 0.79 for SC, 0.94 for silt content, 0.52 for clay content and 0.48 for PH. The study concluded that electrical resistivity measurements could be used as a rapid tool for obtaining the selected topsoil properties.
在位于俄多州阿库雷联邦科技大学内的一块耕地上进行了土壤电阻率测量和土壤性质测定。这是为了在典型的基底复杂环境中建立原位土壤电阻率与选定表土性质之间的关系。利用温纳阵列测量土壤表面0 ~ 50 cm深度的电阻率。电极间距为130 cm (1.3 m)。在2 m × 2 m细胞的中点处采集深度为50 cm的土壤样品。这些分析的性质包括:水分含量、粒度分析、有机物(OM)、pH值和电导率。回归分析结果表明，土壤内质能与土壤性状的相关系数为0.90,SC为0.63,CC为0.74,OM为0.57,EC为0.94。除SC与PH呈非显著相关(0.52和0.30)外。对推导出的经验模型进行验证，得出的观测结果与预测结果之间的相关系数分别为:MC 0.94、OM 0.74、EC 0.93、SC 0.79、粉砂含量0.94、粘土含量0.52和ph 0.48。研究得出结论，电阻率测量可以作为一种快速获取所选表土性质的工具。
{"title":"Development of empirical models for analysis of subsoil agricultural parameters from resistivity measurement in a basement complex terrain","authors":"A. D Adebiyi, K. Adiat, A. B Eluwole","doi":"10.1080/20909977.2020.1732571","DOIUrl":"https://doi.org/10.1080/20909977.2020.1732571","url":null,"abstract":"ABSTRACT Soil electrical resistivity measurements and soil properties determination were carried out at an arable plot located within the Federal University of Technology, Akure, Ondo State. This was with a view to establishing relationship between in-situ soil resistivity and selected topsoil properties in a typical basement complex environment. Electrical Resistivity was measured from the soil surface at 0 to 50 cm soil depths using Wenner Array. Electrode spacing of 130 cm (1.3 m) was utilized. Soil samples were collected to a depth of 50 cm at the mid points of 2 m by 2 m cell. These were analyzed for properties that include: moisture content, particle size analysis, Organic Matter (OM), pH and electrical conductivity. The regression analysis plots show that ER correlate significantly to soil properties, with coefficient of correlation of 0.90 for MC, 0.63 for SC, 0.74 for CC, 0.57 for OM, 0.94 for EC. Except for SC and PH that shows a non-significant correlation of 0.52 and 0.30 respectively. Validation of the derived empirical model gives a coefficient of correlation between the observed and predicted result as 0.94 for MC, 0.74 for OM, 0.93 for EC, 0.79 for SC, 0.94 for silt content, 0.52 for clay content and 0.48 for PH. The study concluded that electrical resistivity measurements could be used as a rapid tool for obtaining the selected topsoil properties.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"1 1","pages":"260 - 271"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83107435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1794445
Abd el-aziz Khairy Abd el-aal, H. E. Abdelhafiez, H. Saadalla, M. S. Soliman
ABSTRACT In this work, we publish a moment-local magnitude scale catalogue for the Egyptian National Seismic Network (ENSN) since 1997 to 2019 as necessary for the study of seismicity and seismic hazard estimation. Every year, the ENSN publish an annual bulletin of local and regional earthquakes recorded by the network with local magnitude (Ml) scale. The ENSN was recorded more than 36,730 approximately for local events since 1997. In this work, the Moment magnitudes (Mw) are computed for small earthquakes using a spectral analysis method, while the Moment magnitudes of moderate and large earthquakes are obtained using a complete waveform inversion and moment tensor techniques. An empirical relationship between moment magnitude (Mw) and local magnitude (Ml) of the earthquakes are developed using a linear regression. The Mw–Ml relationship used in this study was as follows: Mw = 0.69 Ml + 0.58 for earthquakes with magnitude ≤3 Mw = 0.95 Ml – 0.15 for earthquakes with magnitude 3< ML≤6 The ENSN local magnitude (Ml) catalogue was converted to a moment magnitude (Mw) catalogue and attached as a supplementary material with this article for use by the researchers and authors in tectonic studies and seismic hazard evaluation of the region.
在这项工作中，我们发布了埃及国家地震台网(ENSN)自1997年至2019年的瞬间局地震级目录，这是研究地震活动性和地震危险性估计所必需的。每年，欧洲地震台网都会以当地震级(Ml)为尺度发布台网记录的局地和区域地震的年度公报。自1997年以来，本地事件的ENSN记录约超过36,730。在这项工作中，使用频谱分析方法计算小地震的矩震级(Mw)，而使用完整的波形反演和矩张量技术获得中地震和大地震的矩震级。利用线性回归，建立了矩震级(Mw)和局地震级(Ml)之间的经验关系。本文使用的Mw - Ml关系为:Mw = 0.69 Ml + 0.58，震级≤3,Mw = 0.95 Ml - 0.15，震级< Ml≤6。enn局地震级(Ml)目录转换为矩震级(Mw)目录，作为本文的补充资料，供研究人员和作者在该地区的构造研究和地震危险性评价中使用。
{"title":"A homogenous moment magnitude and local magnitude scaling relation for earthquakes in Egypt","authors":"Abd el-aziz Khairy Abd el-aal, H. E. Abdelhafiez, H. Saadalla, M. S. Soliman","doi":"10.1080/20909977.2020.1794445","DOIUrl":"https://doi.org/10.1080/20909977.2020.1794445","url":null,"abstract":"ABSTRACT In this work, we publish a moment-local magnitude scale catalogue for the Egyptian National Seismic Network (ENSN) since 1997 to 2019 as necessary for the study of seismicity and seismic hazard estimation. Every year, the ENSN publish an annual bulletin of local and regional earthquakes recorded by the network with local magnitude (Ml) scale. The ENSN was recorded more than 36,730 approximately for local events since 1997. In this work, the Moment magnitudes (Mw) are computed for small earthquakes using a spectral analysis method, while the Moment magnitudes of moderate and large earthquakes are obtained using a complete waveform inversion and moment tensor techniques. An empirical relationship between moment magnitude (Mw) and local magnitude (Ml) of the earthquakes are developed using a linear regression. The Mw–Ml relationship used in this study was as follows: Mw = 0.69 Ml + 0.58 for earthquakes with magnitude ≤3 Mw = 0.95 Ml – 0.15 for earthquakes with magnitude 3< ML≤6 The ENSN local magnitude (Ml) catalogue was converted to a moment magnitude (Mw) catalogue and attached as a supplementary material with this article for use by the researchers and authors in tectonic studies and seismic hazard evaluation of the region.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"25 1","pages":"532 - 538"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78229555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1746893
I. Gaafar, M. S. Abu El Ghar, T. Ibrahim, M. Diab
ABSTRACT The present study deals with geologic and mineralogic studies as well as gamma-ray spectrometric survey for uranium potential phosphates of Duwi Formation and environmental assessment at Gabal Abu Had environ. These phosphate deposits are considered as an important potential resource for uranium and rare earth elements as by-products. The study area lies to the NE of Qena town and dissected by Qena – Safaga asphaltic road. The Duwi Formation in the study area conformably overlies Qusseir Formation and underlies Dakhla Formation; this succession is capped with Esna and Thebes Formations and eroded along wadis which are filled with Quaternary deposits. Phosphate deposits (Duwi Formation) of Abu Had area are enriched with uranium, which may be extracted as a by-product of making fertilisers. Petrographic studies indicate that phosphate beds are composed of phosphatic particles which include collophane grains, bioclasts (bone and teeth fragments), as well as, non-phosphatic particles which include quartz, calcite and pyrite embedded in silica, calcite or iron oxides cement. XRD results showed that hydroxylapatite is the principal phosphate mineral, and the non-phosphate minerals include calcite, quartz, gypsum and anhydrite. Ground gamma-ray spectrometric results indicated that the study area has K values range from 0.2% to 4.4%, eTh values range from 0.5 to 18 ppm and eU values range from 0.5 to 100 ppm. The phosphate-bearing beds of Duwi Formation have the highest values of eU reach up to 100 ppm. The uranium anomalies mostly elongated in NW-SE trend that related to the NW-SE strike-slip faults of the area. The average value of annual effective dose rates of phosphates at Abu Had area equals 0.32 mSv/y which, less than the worldwide permissible level of annual effective dose rate (1 mSv/y).
{"title":"Mineralogy and ground gamma-ray spectrometric investigation for phosphates of Gabal Abu Had area, Central Eastern Desert, Egypt","authors":"I. Gaafar, M. S. Abu El Ghar, T. Ibrahim, M. Diab","doi":"10.1080/20909977.2020.1746893","DOIUrl":"https://doi.org/10.1080/20909977.2020.1746893","url":null,"abstract":"ABSTRACT The present study deals with geologic and mineralogic studies as well as gamma-ray spectrometric survey for uranium potential phosphates of Duwi Formation and environmental assessment at Gabal Abu Had environ. These phosphate deposits are considered as an important potential resource for uranium and rare earth elements as by-products. The study area lies to the NE of Qena town and dissected by Qena – Safaga asphaltic road. The Duwi Formation in the study area conformably overlies Qusseir Formation and underlies Dakhla Formation; this succession is capped with Esna and Thebes Formations and eroded along wadis which are filled with Quaternary deposits. Phosphate deposits (Duwi Formation) of Abu Had area are enriched with uranium, which may be extracted as a by-product of making fertilisers. Petrographic studies indicate that phosphate beds are composed of phosphatic particles which include collophane grains, bioclasts (bone and teeth fragments), as well as, non-phosphatic particles which include quartz, calcite and pyrite embedded in silica, calcite or iron oxides cement. XRD results showed that hydroxylapatite is the principal phosphate mineral, and the non-phosphate minerals include calcite, quartz, gypsum and anhydrite. Ground gamma-ray spectrometric results indicated that the study area has K values range from 0.2% to 4.4%, eTh values range from 0.5 to 18 ppm and eU values range from 0.5 to 100 ppm. The phosphate-bearing beds of Duwi Formation have the highest values of eU reach up to 100 ppm. The uranium anomalies mostly elongated in NW-SE trend that related to the NW-SE strike-slip faults of the area. The average value of annual effective dose rates of phosphates at Abu Had area equals 0.32 mSv/y which, less than the worldwide permissible level of annual effective dose rate (1 mSv/y).","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"82 1","pages":"375 - 392"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72904796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2019.1706834
G. El-Qady, Safaa E. A. Shanab, M. Omran, A. Embaby, H. Aboelkhair
ABSTRACT A geoelectrical resistivity survey supported by hydrochemical analysis was managed in Ayun Musa area to detect the groundwater aquifer, differentiate the subsurface layers and estimate the groundwater quality of Ayun Musa springs. A suit of 29 vertical electrical soundings (VES) of AB/2 varying from 1 up to 1000 metres were measured in the study area to achieve the goals. Water samples were collected from ten localities in the study area. Interpretation of the VESes using 1D and 2D algorithms indicates the presence of five geoelectric units of different resistivities. The main water bearing formation related to the Lower Cretaceous represented by the fifth layer and located at depth range from 205 to 256 m below the surface. On the other hand, Interpretation of hydrochemical analysis reveals that the groundwater in Ayun Musa area is brackish in nature. The sequence of the abundance of the major ions is in the following order Na+> Mg+2 > Ca+2 and Cl−> SO4 −2> HCO3 −. This suggests active dissolution and ion exchange processes and the high chloride and sodium concentrations indicate a major influence by seawater. Generally, the groundwater samples in the study area are not suitable for domestic purposes.
{"title":"Hydrogeophysical study at an arid area: case study at Ayun Musa hot springs, Sinai, Egypt","authors":"G. El-Qady, Safaa E. A. Shanab, M. Omran, A. Embaby, H. Aboelkhair","doi":"10.1080/20909977.2019.1706834","DOIUrl":"https://doi.org/10.1080/20909977.2019.1706834","url":null,"abstract":"ABSTRACT A geoelectrical resistivity survey supported by hydrochemical analysis was managed in Ayun Musa area to detect the groundwater aquifer, differentiate the subsurface layers and estimate the groundwater quality of Ayun Musa springs. A suit of 29 vertical electrical soundings (VES) of AB/2 varying from 1 up to 1000 metres were measured in the study area to achieve the goals. Water samples were collected from ten localities in the study area. Interpretation of the VESes using 1D and 2D algorithms indicates the presence of five geoelectric units of different resistivities. The main water bearing formation related to the Lower Cretaceous represented by the fifth layer and located at depth range from 205 to 256 m below the surface. On the other hand, Interpretation of hydrochemical analysis reveals that the groundwater in Ayun Musa area is brackish in nature. The sequence of the abundance of the major ions is in the following order Na+> Mg+2 > Ca+2 and Cl−> SO4 −2> HCO3 −. This suggests active dissolution and ion exchange processes and the high chloride and sodium concentrations indicate a major influence by seawater. Generally, the groundwater samples in the study area are not suitable for domestic purposes.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"13 1","pages":"16 - 29"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79100295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/20909977.2020.1728866
E. Falayi, A. Adewole, A. D. Adelaja, O. Ogundile, T. Roy-Layinde
ABSTRACT We investigate the time series of solar wind parameters (interplanetary magnetic field, Bz and solar wind speed, Vx) and geomagnetic indices (disturbance storm time, Dst and auroral electrojet, AE) using wavelet analysis and nonlinear dynamics time series techniques. The data were collected from the Flight Center Space Physics Data Facility (GSFC/SPDF) OMNIWEB interface between 2008 and 2017. Wavelet power spectrum (WPS) analysis assists in breaking down the time series of Bz, Vx, Dst and AE parameters into different scales. It was noted that there is a greater concentration of power between the 512 and 1024 months bands across the Bz, Vx, Dst and AE parameters. We also applied non-linear time series modelling methods to examine the Bz, Vx, Dst and AE parameters. We utilised both the time delay and embedded dimension in computing average mutual information (AMI) and false nearest neighbors (FNN), respectively. The Lyapunov exponent (LE) is used to express the complexity of the nonlinear dynamics based on embedding parameters. The Lyapunov exponents depict positive values which confirm that the complex solar wind parameters and the geomagnetic indices are deterministic chaotic systems. The results show noticeable chaotic characteristics in the Bz, Vx, Dst and AE parameters.
{"title":"Study of nonlinear time series and wavelet power spectrum analysis using solar wind parameters and geomagnetic indices","authors":"E. Falayi, A. Adewole, A. D. Adelaja, O. Ogundile, T. Roy-Layinde","doi":"10.1080/20909977.2020.1728866","DOIUrl":"https://doi.org/10.1080/20909977.2020.1728866","url":null,"abstract":"ABSTRACT We investigate the time series of solar wind parameters (interplanetary magnetic field, Bz and solar wind speed, Vx) and geomagnetic indices (disturbance storm time, Dst and auroral electrojet, AE) using wavelet analysis and nonlinear dynamics time series techniques. The data were collected from the Flight Center Space Physics Data Facility (GSFC/SPDF) OMNIWEB interface between 2008 and 2017. Wavelet power spectrum (WPS) analysis assists in breaking down the time series of Bz, Vx, Dst and AE parameters into different scales. It was noted that there is a greater concentration of power between the 512 and 1024 months bands across the Bz, Vx, Dst and AE parameters. We also applied non-linear time series modelling methods to examine the Bz, Vx, Dst and AE parameters. We utilised both the time delay and embedded dimension in computing average mutual information (AMI) and false nearest neighbors (FNN), respectively. The Lyapunov exponent (LE) is used to express the complexity of the nonlinear dynamics based on embedding parameters. The Lyapunov exponents depict positive values which confirm that the complex solar wind parameters and the geomagnetic indices are deterministic chaotic systems. The results show noticeable chaotic characteristics in the Bz, Vx, Dst and AE parameters.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"29 1","pages":"226 - 237"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82172582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：