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11.
A. I. Arbab Saadia E. Salih Sultan H. Hassan Ahmed El Agali Husam Abubaker 《Astrophysics and Space Science》2013,348(1):57-63
Using a new approach, we have obtained a formula for calculating the rotation period and radius of planets. In the ordinary gravitomagnetism the gravitational spin (S) orbit (L) coupling, $\vec{L}\cdot\vec{S}\propto L^{2}$ , while our model predicts that $\vec{L}\cdot\vec{S}\propto\frac{m}{M}L^{2}$ , where M and m are the central and orbiting masses, respectively. Hence, planets during their evolution exchange L and S until they reach a final stability at which MS∝mL, or $S\propto\frac{m^{2}}{v}$ , where v is the orbital velocity of the planet. Rotational properties of our planetary system and exoplanets are in agreement with our predictions. The radius (R) and rotational period (D) of tidally locked planet at a distance a from its star, are related by, $D^{2}\propto\sqrt{\frac{M}{m^{3}}}R^{3}$ and that $R\propto\sqrt{\frac {m}{M}}a$ . 相似文献
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The main results that derived from this study is the quantitative determination of subsurface water balance and the water loses along flow line during drought decade (before 2000–2009), with intense exploitation of groundwater from water wells. The hydrogeological data are presented as spatial distribution maps and three dimensional models. The results are correlated with the main hydrogeologic control points including (storage and transmissivity coefficients, groundwater depths, aquifers thickness, lateral extensions, well productivity) to determine the preferable hydrogeologic districts for development and exploitations, avoiding groundwater depletion as captured zone flow. Based on the isotope analysis of deuterium, oxygen-18, tritium, carbon-13, and carbon-14, the recharge of the aquifer is originated to direct infiltration of atmospheric water through exposure outcrops within Hauran catchments area. The isotope compositions also show that the groundwater is a mixture of an old groundwater with modern recharge in the areas adjacent to Rutba. The fact that the Mullusi aquifer is of major importance as the water supply of people in Rutba region, particularly, for increasing demand of water resources and sustainability assessment in the future, this study developed a reliable strategic suggested plan in groundwater supply, based on groundwater exploitation and amount of safe yield within Dhabaa basin. 相似文献
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Salih Alcay 《Geomagnetism and Aeronomy》2021,61(4):600-618
Geomagnetism and Aeronomy - This paper investigates the performance of International Reference Ionosphere (IRI-2016) in predicting the variation of the Total Electron Content (TEC) over six IGS... 相似文献
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Ak&#x;n Kürer Alexandros Chatzipetros Salih Zeki Tutkun Spyros Pavlides
zkan Ate Sotiris Valkaniotis 《Tectonophysics》2008,453(1-4):263
The Yenice–Gönen Fault (YGF) is one of the most important active tectonic structures in the Biga peninsula. On March 18, 1953, a destructive earthquake (Mw = 7.2) occurred on the YGF, which is considered to be a part of the southern branch of the North Anatolian Fault Zone (NAFZ). A 70 km-long dextral surface rupture formed during the Yenice–Gönen Earthquake (YGE).In this study, structural and palaeoseismological features of the YGF have been investigated. The YGF surface ruptures have been mapped and three trenches were excavated at Muratlar, Karaköy and Seyvan sites.According to the palaeoseismic interpretation and the results of 14C AMS dating, Seyvan trench shows that an earthquake of palaeoseismic age ca. 620 AD ruptured a different strand of the 1953 fault, producing rather significant surface rupture displacement, while there are indications that at least two older events occurred during the past millennia. Another set of trenches excavated near Gönen town (Muratlar village) revealed extensive liquefaction not only during the 1953 event, but also during a previous earthquake, dated at 1440 AD. The Karaköy trench shows no indications of recent reactivations.Based on the trenching results, we estimate a recurrence interval of 660 ± 160 years for large morphogenic earthquakes, creating linear surface ruptures. The maximum reported displacement during the 1953 earthquake was 4.2 m. Taking into account the palaeoseismologically determined earthquake recurrence interval and maximum displacement, slip-rate of the YGF has been calculated to be 6.3 mm/a, which is consistent with present-day velocities determined by GPS measurements. According to the geological investigations, cumulative displacement of the YGF is 2.3 km. This palaeoseismological study contributes to model the behaviour of large seismogenic faults in the Biga Peninsula. 相似文献
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Very hot,very shallow hydrothermal dolomitization: An example from the Maritime Alps (north‐west Italy–south‐east France) 
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下载免费PDF全文 Luca Barale Carlo Bertok Namam Salih Talabani Anna d'Atri Luca Martire Fabrizio Piana Alain Préat 《Sedimentology》2016,63(7):2037-2065
In the Maritime Alps (north‐west Italy – south‐east France), the Middle Triassic–lowermost Cretaceous platform carbonates of the Provençal Domain locally show an intense dolomitization. Dolomitized bodies, irregularly shaped and variable in size from some metres to hundreds of metres, are associated with tabular bodies of dolomite‐cemented breccias, cutting the bedding at a high angle, and networks of dolomite veins. Field and petrographic observations indicate that dolomitization was a polyphase process, in which episodes of hydrofracturing and host‐rock dissolution, related to episodic expulsion of overpressured fluids through faults and fracture systems, were associated with phases of host‐rock dolomitization and void cementation. Fluid inclusion analysis indicates that dolomitizing fluids were relatively hot (170 to 260°C). The case study represents an outstanding example of a fossil hydrothermal system, which significantly contributes to the knowledge of such dolomitization systems in continental margin settings. The unusually favourable stratigraphic framework allows precise constraint of the timing of dolomitization (earliest Cretaceous) and, consequently, direct evaluation of the burial setting of dolomitization which, for the upper part of the dolomitized succession, was very shallow or even close to the surface. The described large‐scale hydrothermal system was probably related to deep‐rooted faults, and provides indirect evidence of a significant earliest Cretaceous fault activity in this part of the Alpine Tethys European palaeomargin. 相似文献
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Mohamed A. Mohamed Salih 《GeoJournal》1995,36(1):71-78
The Nuba claim that they are the indigenous inhabitants of the Nuba Mountains of the Sudan. Indigenous peoples here refers to pre-existence, non-dominance, cultural difference and self-identification as indigenous. As such the Nuba are politically and economically marginalized and suffered persecution and dominance under external and internal colonialism. Human rights abuses, including genocide and ethnocide (or cultural genocide) have persisted and the Nuba are increasingly under pressure to give up their traditional way of life, and lose access to their lands and other natural resources for immigrant Baggara and Jellaba ethnic groups are supported by the state. This paper traces the origins of Nuba abuse and oppression, and delineates their uneasy and turbulent relationship with the Sudanese state. 相似文献
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Hajo Idriss Isam Salih Abdulaziz S. Alaamer M. A. AL-Rajhi Alshfia Osman Tahir Elamin Adreani M. Y. Abdelgalil Nagi I. Ali 《Acta Geophysica》2018,66(4):673-681
This study shows the assessment of radiation hazard parameters due to terrestrial radionuclides in the soil around artisanal gold mining for addressing the issue of natural radioactivity in mining areas. Hence, the levels 238U, 232Th, 40K and 226Ra in soil (using gamma spectrometry), 222Rn in soil and 222Rn in air were determined. Radiation hazard parameters were then computed. These include absorbed dose D, annual effective dose E, radium equivalent activity Raeq, external hazard Hex, annual gonadal dose equivalent hazard index AGDE and excess lifetime cancer risk ELCR due to the inhalation of radon (222Rn) and consumption of radium (226Ra) in vegetation. Uranium (238U), thorium (232Th) and potassium (40K) averages were, respectively, 26, 36 and 685 Becquerel per kilogram (Bq kg?1). Soil radon (4671 Bq m?3) and radon in air (14.77 Bq m?3) were found to be less than worldwide data. Nevertheless, the average 40K concentration was 685 Bq kg?1. This is slightly higher than the United Nations Scientific Committee on the Effects of Atomic Radiation average value of 412 Bq kg?1. The obtained result indicates that some of the radiation hazard parameters seem unsavory. The mean value of absorbed dose rate (62.49 nGy h?1) was slightly higher than average value of 57 nGy h?1 (~?45% from 40K), and that of AGDE (444 μSv year?1) was higher than worldwide average reported value (300 μSv year?1). This study highlights the necessity to launch extensive nationwide radiation protection program in the mining areas for regulatory control. 相似文献
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Natural Resources Research - This study aims to evaluate the use of Tigris River sediments as abrasives for polishing marble surfaces to achieve a usable form as floor tiles, facing stones and... 相似文献
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Breaking wave loads on coastal structures depend primarily on the type of wave breaking at the instant of impact. When a wave breaks on a vertical wall with an almost vertical front face called the “perfect breaking”, the greatest impact forces are produced. The correct prediction of impact forces from perfect breaking of waves on seawalls and breakwaters is closely dependent on the accurate determination of their configurations at breaking. The present study is concerned with the determination of the geometrical properties of perfect breaking waves on composite-type breakwaters by employing artificial neural networks. Using a set of laboratory data, the breaker crest height, hb, breaker height, Hb, and water depth in front of the wall, dw, from perfect breaking of waves on composite breakwaters are predicted using the artificial neural network technique and the results are compared with those obtained from linear and multi-linear regression models. The comparisons of the predicted results from the present models with measured data show that the hb, Hb and dw values, which represent the geometry of waves breaking directly on composite breakwaters, can be predicted more accurately by artificial neural networks compared to linear and multi-linear regressions. 相似文献