Pub Date : 2021-01-01DOI: 10.1080/20909977.2021.1938893
A. Adebayo, E. Ariyibi, O. Dasho, C. Adenika, Emmanuel O. Olagunju
ABSTRACT This study delineates surface and subsurface structural features in the hard rock terrain of Osun State using magnetic data and satellite remote sensing imageries. To achieve this aim, several image enhancement methods were applied to the magnetic data and satellite remotely sensed imageries to improve visualization and interpretation. The subsurface lineaments were detected and traced out from the maxima of Horizontal Gradient Magnitude, peaks of Analytical Signal Magnitude, and an Euler solution of Osun state. The magnetic lineament map reveals that the structural trend in the area is dominant by NE-SW and NNE-SSW. These structural trends were found to be consistent with the regional tectonics of the Southwest Basement of Nigeria. The NE-SW is the most conspicuous structural trend in the study area. The satellite imageries depict a characteristics feature of the occurrence of underlying structures in the basement complex of Osun State. The major lineament trends delineated in the composite surface lineament map are the NE-SW, NNE-SSW, and ENE-WSW directions. The 2.5 D model across the unmapped lineaments confirmed the existence of a thin dyke’s characteristic of fracture/fault in a typical basement complex terrain. The derived lineaments may serve as a reference for future geological and structural mapping.
{"title":"Structural interpretation of magnetic and satellite remotely sensed data of Osun State, Southwestern, Nigeria","authors":"A. Adebayo, E. Ariyibi, O. Dasho, C. Adenika, Emmanuel O. Olagunju","doi":"10.1080/20909977.2021.1938893","DOIUrl":"https://doi.org/10.1080/20909977.2021.1938893","url":null,"abstract":"ABSTRACT This study delineates surface and subsurface structural features in the hard rock terrain of Osun State using magnetic data and satellite remote sensing imageries. To achieve this aim, several image enhancement methods were applied to the magnetic data and satellite remotely sensed imageries to improve visualization and interpretation. The subsurface lineaments were detected and traced out from the maxima of Horizontal Gradient Magnitude, peaks of Analytical Signal Magnitude, and an Euler solution of Osun state. The magnetic lineament map reveals that the structural trend in the area is dominant by NE-SW and NNE-SSW. These structural trends were found to be consistent with the regional tectonics of the Southwest Basement of Nigeria. The NE-SW is the most conspicuous structural trend in the study area. The satellite imageries depict a characteristics feature of the occurrence of underlying structures in the basement complex of Osun State. The major lineament trends delineated in the composite surface lineament map are the NE-SW, NNE-SSW, and ENE-WSW directions. The 2.5 D model across the unmapped lineaments confirmed the existence of a thin dyke’s characteristic of fracture/fault in a typical basement complex terrain. The derived lineaments may serve as a reference for future geological and structural mapping.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"12 1","pages":"347 - 360"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78253659","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 : 2021-01-01DOI: 10.1080/20909977.2021.2000794
M. Abdel-Sabour, M. Nouh, S. Ata, M. Darwish
ABSTRACT In the present paper, analysis of the BVR photometric observations using the 1.88 m telescope of Kottamia Astronomical Observatory (Egypt) is reported. The fundamental mode with many harmonics is determined using Fourier analysis of the light curves. The photometric analysis yielded a value of the period 0d.1040919125, which is in good agreement with the period calculated by previous studies. Seventy-tow new times of maximum light are presented together with180 times from literature. An updated ephemeris for the star is determined and its O-C is presented. Assuming its period is increasing and is changing a little, a near value of (1/P) dP/dt that is determined by previous studies is calculated. Also, the amplitude behaviour is secular at a rate of about Δv = 7.99x10−4 mag./year. By using empirical relations, we determined the physical parameters of YZ Boo as; the radius log(R*/R⊙) = 1.7804 ± 0.044, the bolometric magnitude M bol = 1.71637 ± 0.132, the mass M= 1.943 ± 0.102MΘ, the surface gravity log g = 3.853 ± 0.111, the pulsation constant Q = 0.033 ± 0.002, and distance 544.137 ± 20.565pc.
{"title":"Frequency and photometric analysis of the short period pulsating star YZ Boo","authors":"M. Abdel-Sabour, M. Nouh, S. Ata, M. Darwish","doi":"10.1080/20909977.2021.2000794","DOIUrl":"https://doi.org/10.1080/20909977.2021.2000794","url":null,"abstract":"ABSTRACT In the present paper, analysis of the BVR photometric observations using the 1.88 m telescope of Kottamia Astronomical Observatory (Egypt) is reported. The fundamental mode with many harmonics is determined using Fourier analysis of the light curves. The photometric analysis yielded a value of the period 0d.1040919125, which is in good agreement with the period calculated by previous studies. Seventy-tow new times of maximum light are presented together with180 times from literature. An updated ephemeris for the star is determined and its O-C is presented. Assuming its period is increasing and is changing a little, a near value of (1/P) dP/dt that is determined by previous studies is calculated. Also, the amplitude behaviour is secular at a rate of about Δv = 7.99x10−4 mag./year. By using empirical relations, we determined the physical parameters of YZ Boo as; the radius log(R*/R⊙) = 1.7804 ± 0.044, the bolometric magnitude M bol = 1.71637 ± 0.132, the mass M= 1.943 ± 0.102MΘ, the surface gravity log g = 3.853 ± 0.111, the pulsation constant Q = 0.033 ± 0.002, and distance 544.137 ± 20.565pc.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"10 1","pages":"416 - 422"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79791056","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 : 2021-01-01DOI: 10.1080/20909977.2021.1900526
T. O. Lawal, J. Sunday, korede Fawale, M. Salami, T. Adewumi
ABSTRACT As part of the effort to have updated knowledge about the metallic source location, subsurface structures and depth information responsible for mineralization in Lafiaji and its environs, North-central Nigeria, a magnetic data of the area has been analyzed using combinations of mathematical techniques. These techniques include Total Horizontal Derivatives (THD), Tilt Derivatives (TD), CET grid technique, Euler Deconvolution (ED), and Fourier technique. Reduction to equator (RTE) was performed on the magnetic data and subjected to the mathematical techniques. The TD, THD and CET techniques revealed various striking subsurface structures moving in NE, SW, NW SE, EW direction and forms banded gneisses and muscovite schist that are intimately linked through the crustal progress going on in the basement rock of the area. The ED solutions did not only reveal various structural sources but also determines the best index with the average depth values of various metallic sources. Also, the result from the spectral analysis ranges from 1.40 km - 3.50 km. In conclusion, this study did not only demonstrate the usefulness of HRAM data in revealing the nature and extent of subsurface structural features and depth information but also shows intense tectonic deformation of the basement structures responsible for mineral exploration.
{"title":"Use of Magnetic anomaly data to delineate subsurface structures and depth characterization of Lafiagi and its environs, Northcentral Nigeria","authors":"T. O. Lawal, J. Sunday, korede Fawale, M. Salami, T. Adewumi","doi":"10.1080/20909977.2021.1900526","DOIUrl":"https://doi.org/10.1080/20909977.2021.1900526","url":null,"abstract":"ABSTRACT As part of the effort to have updated knowledge about the metallic source location, subsurface structures and depth information responsible for mineralization in Lafiaji and its environs, North-central Nigeria, a magnetic data of the area has been analyzed using combinations of mathematical techniques. These techniques include Total Horizontal Derivatives (THD), Tilt Derivatives (TD), CET grid technique, Euler Deconvolution (ED), and Fourier technique. Reduction to equator (RTE) was performed on the magnetic data and subjected to the mathematical techniques. The TD, THD and CET techniques revealed various striking subsurface structures moving in NE, SW, NW SE, EW direction and forms banded gneisses and muscovite schist that are intimately linked through the crustal progress going on in the basement rock of the area. The ED solutions did not only reveal various structural sources but also determines the best index with the average depth values of various metallic sources. Also, the result from the spectral analysis ranges from 1.40 km - 3.50 km. In conclusion, this study did not only demonstrate the usefulness of HRAM data in revealing the nature and extent of subsurface structural features and depth information but also shows intense tectonic deformation of the basement structures responsible for mineral exploration.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"5 1","pages":"155 - 167"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89541314","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 : 2021-01-01DOI: 10.1080/20909977.2021.1929745
A. Diab, Hany M. Khalil
ABSTRACT Obaiyed field lies in northern west Shushan Basin, which considers one of the largest Mesozoic coastal basins in northeast Africa, with high thickness sediment from the Jurassic to Palaeogene. The petrophysical parameters show difficulty in the development of the high gas reserve in the field, which led us to assess the geological systems that could constrain the formation and evolution of the basin concerning the study field. We simulated the tectonic evolution of the basin using a 1D-Airy isostasy backstripping technique with python coding and PetoMode® software. Also, we evaluated the current reservoir petrophysical parameters using TechLog® software. Based on integrating our results, we propose that the Shushan Basin represents a natural case of a Continuous Basin-Centred Gas accumulations model (CBCG) because of four main reasons: a) the vast extension of the Khatatba Formation, b) the coexistence of the source and the reservoir rocks in the Khatatba Formation, c) the low-permeability and gas saturation accumulations of the Lower Safa Member and d) the abnormal pressure of the Lower Safa reservoir because of its compartmentalization, where each compartment has its pressure peak. At a regional scale, this study highlights the effect of tectonics in the evolution of the basins.
{"title":"Quantitative assessment of the tight gas reservoirs in the Obaiyed field, Shushan Basin, NW Egypt","authors":"A. Diab, Hany M. Khalil","doi":"10.1080/20909977.2021.1929745","DOIUrl":"https://doi.org/10.1080/20909977.2021.1929745","url":null,"abstract":"ABSTRACT Obaiyed field lies in northern west Shushan Basin, which considers one of the largest Mesozoic coastal basins in northeast Africa, with high thickness sediment from the Jurassic to Palaeogene. The petrophysical parameters show difficulty in the development of the high gas reserve in the field, which led us to assess the geological systems that could constrain the formation and evolution of the basin concerning the study field. We simulated the tectonic evolution of the basin using a 1D-Airy isostasy backstripping technique with python coding and PetoMode® software. Also, we evaluated the current reservoir petrophysical parameters using TechLog® software. Based on integrating our results, we propose that the Shushan Basin represents a natural case of a Continuous Basin-Centred Gas accumulations model (CBCG) because of four main reasons: a) the vast extension of the Khatatba Formation, b) the coexistence of the source and the reservoir rocks in the Khatatba Formation, c) the low-permeability and gas saturation accumulations of the Lower Safa Member and d) the abnormal pressure of the Lower Safa reservoir because of its compartmentalization, where each compartment has its pressure peak. At a regional scale, this study highlights the effect of tectonics in the evolution of the basins.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"16 1","pages":"320 - 332"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82632276","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 : 2021-01-01DOI: 10.1080/20909977.2021.1904550
Akinshipe R. Bayo, K. Okiongbo, Geoffrey C. Sorronadi-Ononiwu
ABSTRACT In order to quantify the P- and S-wave velocities, dynamic elastic moduli and bearing capacity of shallow alluvial sediments, seismic refraction and cone penetration test (CPTu) soundings were carried out in two sites in Yenagoa. The seismic refraction data was analysed using the intercept–time technique to obtain the seismic velocities which were subsequently used to estimate the dynamic elastic moduli. The relevant CPTu data were emplaced into an established empirical equation to determine the shear wave velocity (V s), with which the compressional wave velocity (V p) was estimated. Combing the compressional and shear wave velocities, the dynamic elastic moduli of the shallow sediments were determined within the depth range of 0.5–8.0 m. On comparison, it was observed that the average values of V p and V s from the two methods are fairly in agreement. Significant difference in the average values was only observed in the dynamic elastic moduli. Correlation of the Vs-wave and the dynamic moduli from the CPTu data show linear relationship between S-wave velocity and the dynamic elastic moduli with correlation coefficients (R 2) greater than 0.9 in all cases. These elastic moduli values can be used for the design of foundation of structures, site response and settlement analysis.
{"title":"Determination of elastic moduli and bearing capacity of sediments using geophysical and cone penetration test techniques in Yenagoa, Southern Nigeria","authors":"Akinshipe R. Bayo, K. Okiongbo, Geoffrey C. Sorronadi-Ononiwu","doi":"10.1080/20909977.2021.1904550","DOIUrl":"https://doi.org/10.1080/20909977.2021.1904550","url":null,"abstract":"ABSTRACT In order to quantify the P- and S-wave velocities, dynamic elastic moduli and bearing capacity of shallow alluvial sediments, seismic refraction and cone penetration test (CPTu) soundings were carried out in two sites in Yenagoa. The seismic refraction data was analysed using the intercept–time technique to obtain the seismic velocities which were subsequently used to estimate the dynamic elastic moduli. The relevant CPTu data were emplaced into an established empirical equation to determine the shear wave velocity (V s), with which the compressional wave velocity (V p) was estimated. Combing the compressional and shear wave velocities, the dynamic elastic moduli of the shallow sediments were determined within the depth range of 0.5–8.0 m. On comparison, it was observed that the average values of V p and V s from the two methods are fairly in agreement. Significant difference in the average values was only observed in the dynamic elastic moduli. Correlation of the Vs-wave and the dynamic moduli from the CPTu data show linear relationship between S-wave velocity and the dynamic elastic moduli with correlation coefficients (R 2) greater than 0.9 in all cases. These elastic moduli values can be used for the design of foundation of structures, site response and settlement analysis.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"5 1","pages":"202 - 217"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80731397","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 : 2021-01-01DOI: 10.1080/20909977.2021.1880043
A. Azab, S. Soliman
ABSTRACT The lowermost portion of the sedimentary section in Gulf of Suez basin is mostly of low resolution and hardly interpret. This may be attributed to the bad seismic reflection that stops at a certain limit and fails to reach the deep settings, or due to non-coverage of boreholes. Herein, the gravity data was reinterpreted utilizing the stripping technique as an alternative tool to overcome the seismic failure. The process simply consists in calculating the gravity effects of the shallow rock-units and removing them from the Bouguer map, then in analyzing the remaining gravity. The ordinary seismic analysis was performed to control the geometry of the Miocene–Post Miocene formations, and density was driven from boreholes. Further analyses were done on the stripped map to obtain details about the deep sources. Generally, the study suggests a complex structure at Pre-Miocene level more than that of Miocene. It delineates two main troughs; Miocene basin to the east and Pre-Miocene basin (involves three sub-basins) to the west, separated by a structural ridge, all are northwesterly oriented. The basement is very disturbed by cross-faults, with no evidence support presence of igneous intrusions along. Two different forces (NW-SE compression and NE-SW tension) affected the region.
{"title":"Source structures at Pre-Miocene level as deduced by gravity stripping","authors":"A. Azab, S. Soliman","doi":"10.1080/20909977.2021.1880043","DOIUrl":"https://doi.org/10.1080/20909977.2021.1880043","url":null,"abstract":"ABSTRACT The lowermost portion of the sedimentary section in Gulf of Suez basin is mostly of low resolution and hardly interpret. This may be attributed to the bad seismic reflection that stops at a certain limit and fails to reach the deep settings, or due to non-coverage of boreholes. Herein, the gravity data was reinterpreted utilizing the stripping technique as an alternative tool to overcome the seismic failure. The process simply consists in calculating the gravity effects of the shallow rock-units and removing them from the Bouguer map, then in analyzing the remaining gravity. The ordinary seismic analysis was performed to control the geometry of the Miocene–Post Miocene formations, and density was driven from boreholes. Further analyses were done on the stripped map to obtain details about the deep sources. Generally, the study suggests a complex structure at Pre-Miocene level more than that of Miocene. It delineates two main troughs; Miocene basin to the east and Pre-Miocene basin (involves three sub-basins) to the west, separated by a structural ridge, all are northwesterly oriented. The basement is very disturbed by cross-faults, with no evidence support presence of igneous intrusions along. Two different forces (NW-SE compression and NE-SW tension) affected the region.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"75 1","pages":"76 - 92"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83821439","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 : 2021-01-01DOI: 10.1080/20909977.2021.1992562
H. A. Abdel Rahman
ABSTRACT In this paper, we estimate distances and generate the mean absolute magnitudes and dispersions for K and M bright dwarfs using two different approaches. The methods are based on the assumption that the absolute and apparent magnitude follows the exponential and Gaussian distributions functions. The effect of Malmquist bias has been studied to show how effective bias is in comparison. We found that the range between the calculated distances for the spectral subtypes K is small (2.6 pcs), while the range in the distance of the spectral subtypes M is a little big (21.6 pcs), and this may be due to the different chemical compositions and evolution scenarios for each spectral subtype. This means that these dwarfs are situated in the same cloud as near and far sides. We spread the dwarfs above and below the galactic plane to gain certain physical properties based on the statistical study and also on the spectral subtypes. The estimated distances from the two approaches are approximately the same but there are noticeable differences between the generated mean absolute magnitudes and dispersions.
{"title":"Statistical distances of the northern sky bright K and M dwarfs with apparent magnitude J < 9","authors":"H. A. Abdel Rahman","doi":"10.1080/20909977.2021.1992562","DOIUrl":"https://doi.org/10.1080/20909977.2021.1992562","url":null,"abstract":"ABSTRACT In this paper, we estimate distances and generate the mean absolute magnitudes and dispersions for K and M bright dwarfs using two different approaches. The methods are based on the assumption that the absolute and apparent magnitude follows the exponential and Gaussian distributions functions. The effect of Malmquist bias has been studied to show how effective bias is in comparison. We found that the range between the calculated distances for the spectral subtypes K is small (2.6 pcs), while the range in the distance of the spectral subtypes M is a little big (21.6 pcs), and this may be due to the different chemical compositions and evolution scenarios for each spectral subtype. This means that these dwarfs are situated in the same cloud as near and far sides. We spread the dwarfs above and below the galactic plane to gain certain physical properties based on the statistical study and also on the spectral subtypes. The estimated distances from the two approaches are approximately the same but there are noticeable differences between the generated mean absolute magnitudes and dispersions.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"58 1","pages":"407 - 415"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89823704","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 : 2021-01-01DOI: 10.1080/20909977.2021.1900525
A. Raj, D. Oliver, Y. Srinivas, J. Viswanath
ABSTRACT Geoelectrical inversion has some problems in inverting data due to the heterogeneous behaviour of Earth. One of the major concerns in inverting the data is due to the influence of noises, which comes from the disturbance due to human interventions, atmospheric variations, and electromagnetic disturbance, etc. . In this paper, we have presented a concept of Neuro Fuzzy algorithm which can interpret the noisy data successfully. Moreover, the data were tested with artificially generated random noise, gaussian noise and missing data. Kanyakumari field region having complex geological structures and its performance is validated with a maximum threshold. Kanyakumari field region having complex geological structures is used and the performance is validated with a maximum threshold. Neuro fuzzy technique has the dominant feature of training and testing the data with utmost accuracy. These implications are made to create the specific Graphical User Interface (GUI) for the algorithm and it works well for all types of Vertical Electrical Sounding (VES) data with good performance results.
{"title":"Optimising noise intervened data processes for inverse geoelectrical problem using adaptive neuro fuzzy inference system (ANFIS)","authors":"A. Raj, D. Oliver, Y. Srinivas, J. Viswanath","doi":"10.1080/20909977.2021.1900525","DOIUrl":"https://doi.org/10.1080/20909977.2021.1900525","url":null,"abstract":"ABSTRACT Geoelectrical inversion has some problems in inverting data due to the heterogeneous behaviour of Earth. One of the major concerns in inverting the data is due to the influence of noises, which comes from the disturbance due to human interventions, atmospheric variations, and electromagnetic disturbance, etc. . In this paper, we have presented a concept of Neuro Fuzzy algorithm which can interpret the noisy data successfully. Moreover, the data were tested with artificially generated random noise, gaussian noise and missing data. Kanyakumari field region having complex geological structures and its performance is validated with a maximum threshold. Kanyakumari field region having complex geological structures is used and the performance is validated with a maximum threshold. Neuro fuzzy technique has the dominant feature of training and testing the data with utmost accuracy. These implications are made to create the specific Graphical User Interface (GUI) for the algorithm and it works well for all types of Vertical Electrical Sounding (VES) data with good performance results.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"6 1","pages":"138 - 154"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91073895","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 : 2021-01-01DOI: 10.1080/20909977.2021.1898142
S. Khalil, U. A. Rahoma, A. H. Hassan, Rashed M. Greeb
ABSTRACT In this paper, we used the data measurements of average hourly and monthly of UV solar radiation from 2003 to 2017 at four different selected locations in Saudi Arabia for optimisation and evaluation of UVB, UVBest., UVI and KtUVB solar radiation and total ozone column TOC (DU). The scattering phenomena on by stratospheric ozone is high extremely attenuation of UVB solar radiation. The predicted values of UVB solar radiation are a good agreement with the measurement of the UVB solar radiation. The accuracy between measured and predicted values of UVB solar radiation in selected locations in the present research varies from 1.27 to 3.87%. The maximum values of the total ozone column TOC are occur between March and April months at all selected locations with exception Taif site which occur between April and may months, and in whole the highest values of TOC occur about Spring time in all study locations.The relation between UVI and (SZA) at all selected locations in the present research is discussed. The monthly average has a correlation coefficient equal to 72%, 82%, 85% and 83% at Al-Baha, Abha, Jeddah and Taif sites, respectively, so the SZA is responsible for variations of UVI by 72%, 82%, 85% and 83% at Al-Baha, Abha, Jeddah and Taif locations for the monthly values respectively.
{"title":"Assessment of UVB solar radiation in four different selected climate locations in Saudi Arabia","authors":"S. Khalil, U. A. Rahoma, A. H. Hassan, Rashed M. Greeb","doi":"10.1080/20909977.2021.1898142","DOIUrl":"https://doi.org/10.1080/20909977.2021.1898142","url":null,"abstract":"ABSTRACT In this paper, we used the data measurements of average hourly and monthly of UV solar radiation from 2003 to 2017 at four different selected locations in Saudi Arabia for optimisation and evaluation of UVB, UVBest., UVI and KtUVB solar radiation and total ozone column TOC (DU). The scattering phenomena on by stratospheric ozone is high extremely attenuation of UVB solar radiation. The predicted values of UVB solar radiation are a good agreement with the measurement of the UVB solar radiation. The accuracy between measured and predicted values of UVB solar radiation in selected locations in the present research varies from 1.27 to 3.87%. The maximum values of the total ozone column TOC are occur between March and April months at all selected locations with exception Taif site which occur between April and may months, and in whole the highest values of TOC occur about Spring time in all study locations.The relation between UVI and (SZA) at all selected locations in the present research is discussed. The monthly average has a correlation coefficient equal to 72%, 82%, 85% and 83% at Al-Baha, Abha, Jeddah and Taif sites, respectively, so the SZA is responsible for variations of UVI by 72%, 82%, 85% and 83% at Al-Baha, Abha, Jeddah and Taif locations for the monthly values respectively.","PeriodicalId":100964,"journal":{"name":"NRIAG Journal of Astronomy and Geophysics","volume":"25 1","pages":"125 - 137"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77996667","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 : 2021-01-01DOI: 10.1080/20909977.2021.1992136
U. Seshavatharam, S. Lakshminarayana
ABSTRACT With reference to our recently proposed Planck Scale White Hole Cosmology (PS-WHC) (Seshavatharam et al. 2021) or Flat Space Cosmology (PS-FSC) (Tatum et al. 2015), we make an attempt to quantify galactic dark matter and flat rotation speeds in terms of galactic visible matter and cosmic mass. Considering recently observed dwarf galaxies having very little dark matter and assuming a time-dependent reference mass unit of we suggest an empirical relation for galactic dark matter via galactic visible mass as, This relation helps in fitting flat rotation speeds starting from 8 km/sec (for Segue-2) to 500 km/sec (for UGC12591). Following the Modified Newtonian Dynamics and understanding galactic flat rotation speed relation with Hubble mass of the universe, ratio of galactic flat rotation speed to speed of light can be shown to be approximately Considering the sum of galactic dark matter and visible matter, ratio of galactic flat rotation speed to speed of light can be shown to be approximately With further study, dark matter’s nature, effect and distribution can be understood in terms of visible matter’s extended gravity and extended theories of gravity can be understood with “distance cosmic mass” rather than the empirical “minimum acceleration”.
参考我们最近提出的普朗克尺度白洞宇宙学(PS-WHC) (Seshavatharam et al. 2021)或平坦空间宇宙学(PS-FSC) (Tatum et al. 2015)，我们试图根据星系可见物质和宇宙质量来量化星系暗物质和平坦旋转速度。考虑到最近观测到的暗物质很少的矮星系，并假设参考质量的时间依赖单位为，我们建议星系暗物质通过星系可见质量的经验关系为，该关系有助于拟合从8公里/秒(对于Segue-2)到500公里/秒(对于UGC12591)的平旋转速度。根据修正牛顿动力学，理解星系平转速度与宇宙哈勃质量的关系，可以得出星系平转速度与光速之比近似为考虑到星系暗物质和可见物质的总和，可以得出星系平转速度与光速之比近似为。效应和分布可以用可见物质的扩展引力来理解，扩展引力理论可以用“距离宇宙质量”而不是经验的“最小加速度”来理解。
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