A second order Jupiter-Saturn planetary theory     

Osman M. Kamel  Abdel Aziz Bakry 《Earth, Moon, and Planets》1983,28(2):113-123

We complete by this part II the establishment of a second order secular Jupiter-Saturn theory. This is achieved by taking into consideration the influence of the indirect part of the planetary disturbing function, and expressing the second order secular Hamiltonian in terms of Poincaré's canonical variables.  相似文献   

Application of Hori's technique in general planetary theory     

Osman M. Kamel 《Earth, Moon, and Planets》1990,49(3):269-276

In this part we present the complete solution of the planetary canonical equations of motion by the method of G. Hori through successive changes of canonical variables using the Lie series. Thus, we can eliminate the long or critical terms of the planetary perturbing function, in our general planetary theory. In our formulas, we neglect perturbation terms of order higher than the third with respect to planetary masses.  相似文献   

Application of Hori technique in general planetary theory     

Osman M. Kamel 《Earth, Moon, and Planets》1989,44(3):275-289

We explain how the first step of Hori-Lie procedure is applied in general planetary theory to eliminate short-period terms. We extend the investigation to the third-order planetary theory. We solved the canonical equations of motion for secular and periodic perturbations by this method, and obtained the first integrals of the system of canonical equations. Also we showed the relation between the determining function in the sense of Hori and the determining function in the sense of Von Zeipel.  相似文献   

Silver and silver-bearing minerals at the Um Samiuki volcanogenic massive sulphide deposit, Eastern Desert, Egypt     

Ibrahim M. Shalaby  Eugen Stumpfl  Hassan M. Helmy  Mahmoud M. El Mahallawi  Omar A. Kamel 《Mineralium Deposita》2004,39(5-6):608-621

The Um Samiuki Zn–Cu–Pb–Ag mineralisation, south Eastern Desert, Egypt is hosted by felsic volcanic rocks which form part of the 712-Ma-old, east-west-trending Shadli Volcanic Belt. Two major occurrences of massive sulphides are present at the top of rhyolitic breccia in the Western and Eastern mine areas. In each occurrence, a bornite-bearing zone is overlain by a pyrite-chalcopyrite-bearing zone and underlain by a disseminated, Cu-depleted zone. In the massive sulphide ore, sphalerite, chalcopyrite, pyrite, galena, bornite and tetrahedrite–tennantite are major minerals, whereas arsenopyrite, pyrrhotite, molybdenite and magnetite are accessory phases. Covellite and digenite are common secondary minerals. Bornite, tetrahedrite–tennantite and covellite contain high amounts of silver (averages of 1.97, 1.39 and 1.82 wt% respectively). Based on mineralogical balance calculations, bornite and covellite accommodate 80% of silver in the Um Samiuki deposit. Ag was incorporated in the crystal structure of the early-crystallised copper sulphides and sulphosalts and silver minerals. The temperature, sequential precipitation of the fluids and the structure of the crystallising phases control the distribution of silver. Post-depositional deformation and metamorphic processes caused liberation, remobilisation and redeposition of silver within the massive sulphides.Editorial handling: D. Lentz  相似文献   

Regional fracture analysis south Latitude 29° N of Egypt and their influence on earthquakes     

Ahmed Farouk Kamel 《Natural Hazards》1994,9(1-2):235-245

Egypt had been subjected to earthquakes of various degrees but earthquake observation in this country started only in 1899. Earthquakes were found in the locations where fractures have relatives high densities.The Fracture pattern of Egypt south Latitude at 29° N was studied regionally based on Landsat images and aerial photomosaics. Fractures in the Eastern Desert have the prominent trends, NW, EW, NNW and ENE, showing high density in the northern and southern parts. These fractures control the distribution of mineral deposits and radioactivity in the basement rocks.Fractures in Western Desert are less remarkable with the main trend NNW, E-W, N-S and NW, showing high density in the central part. The NNW trending fractures have the same direction of sand dunes which cover larger areas in the northwestern part of Western Desert.Based on the geographical distribution of earthquakes in the seismic maps and centers of high fractures density on the structural contour maps, the area south of latitude 29° N of Egypt was divided into three regions: The Red Sea, Western Desert and Aswan Environs. This correlation led to the conclusion that the fractures have an effect on earthquake activity, are trending ENE and WNW in the Red Sea, NW and N-S in the Western Desert and E-W and NNW in Aswan Environs.It should be emphasized that fractures with higher density are more susceptible to earthquakes in the locations characterized by two dominant sets of fractures especially at their intersections.  相似文献   

Seismic damage to segmented buried pipelines     

Kamel Elhmadi  Michael J. O'Rourke 《地震工程与结构动力学》1990,19(4):529-539

Seismic damage to segmented buried pipelines is investigated in this paper. Information on their performance during past earthquakes is reviewed briefly. An analytical model for evaluating the response of long straight runs of segmented buried pipelines to seismic wave propagation is presented. It takes into account the non-linearity as well as the variability of the system characteristics. Also, results from laboratory tests by others are used to establish the relative joint displacement which leads to leakage. These two elements are combined to predict the damage ratio (number of leaks per kilometre) for cast iron pipes with lead caulked joints subject to a joint pull-out failure mode.  相似文献   

Analysis of continuous buried pipelines for seismic wave effects     

Michael J. O'Rourke  Kamel El Hmadi 《地震工程与结构动力学》1988,16(6):917-929

An analysis procedure for seismic wave propagation effects on straight continuous buried pipelines is proposed. It shown that ground strain due to surface waves can be substantially larger than that due to body waves. An elastic model a buried pipeline surrounded by equivalent soil springs indicates that frictional slip between the pipeline and the surrounding soil springs is likely for high ground strains. A method for estimating ground strain due to surface waves, based on data from the 1971 San Fernando earthquake, reviewed. An analysis procedure, which utilizes frictional forces near the soil-pipeline interface, is proposed for surfae wave effects on straight buried continuous pipelines. The proposed procedure is illustrated with an example.  相似文献   

The hydro geochemical characterization of ground waters in Tunisian Chott’s region.     

Samir Kamel  Hamed Younes  Najiba Chkir  Kamel Zouari 《Environmental Geology》2008,54(4):843-854

Tunisian Chott’s region is one of the most productive artesian basins in Tunisia. It is located in the southwestern part of the country, and its groundwater resources are developed for water supply and irrigation. The chemical composition of the water is strongly influenced by the interaction with the basinal sediments and by hydrologic characteristics such as the flow pattern and time of residence. The system is composed of an upper unconfined “Plio-Quaternary” aquifer with a varying thickness of 20–200 m, an intermediate confined/unconfined “Complex Terminal” aquifer about 100 m in thickness and a deeper “Continental Intercalaire” aquifer about 150 m in thickness separated by thick clay and marl layers. The dissolution of evaporites and carbonates explains part of the contained Na⁺, Ca²⁺, Mg²⁺, K⁺, SO₄²⁻ and Cl^-, but other processes, such carbonate precipitation, also contributes to the water composition. The stable isotope composition of waters establishes that the deep groundwater (depleted as compared to present corresponding local rainfall) is ancient water recharged probably during the late Pleistocene and the early Holocene periods. The relatively recent water in the Plio-Quaternary aquifer is composed of mixed waters resulting presumably from upward leakage from the deeper groundwater.  相似文献   

Use of Tunisian raw clay to remove dye from aqueous solution     

Chaâri Islem  Jridi Kamel  Fakhfakh Emna  Jamoussi Fakher  Mnif Adel 《Arabian Journal of Geosciences》2016,9(10):564

This paper presents the first attempt to investigate the potential of Tunisian palygorskite-rich clay (Pal-clay) on the effectiveness of a textile dye “Direct orange 34” (DO34) removal. Important parameters which affect adsorption, such as initial solution pH, contact time, adsorbent mass, initial dye concentration, and temperature, were investigated. The raw Pal-clay was characterized using X-ray diffractometer (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), cation exchange capacity (CEC), specific surface area (SSA) analysis, and point of zero charge (PZC) determination. The results showed that the Pal-clay has a high selectivity for DO34 and had maximum removal efficiency reaching up to about 91 %. The highest adsorption capacity was obtained at 25 °C and pH of 2. The dye uptake process fitted well to the pseudo-second-order kinetic expression and was best described by the Langmuir and Freundlich isotherms. Intra-particle diffusion studies showed that the adsorption mechanism was not exclusively controlled by the diffusion step and was more likely to be governed by external mass transfer. Thermodynamic parameters such as change in free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also calculated. The parameters revealed that the adsorption of dye by the raw clay is spontaneous and exothermic. The results indicate that the Pal-clay has a moderate adsorption capacity towards anionic dye.  相似文献   

Early Eocene orthophragminids and alveolinids from the Jafnayn Formation,N Oman: significance of Nemkovella stockari Less & Özcan, 2007 in Tethys     

Ercan Özcan  İftikhar Ahmed Abbasi  Katica Drobne  Abiraman Govindan  Luigi Jovane  Kamel Boukhalfa 《Geodinamica Acta》2016,28(3):160-184

The upper member of the Jafnayn Formation in Wadi Rusayl and Al Khoud, Seeb Area in north Oman contains Nemkovella stockari Less & Özcan, 2007, an Early Eocene orthophragminid recorded here for the first time from the Arabian Peninsula. N. stockari, the only orthophragminid identified in Jafnayn Formation, is quite distinct from any other species from Tethys in having spiral and orbitoidiform chambers around the isolepidine embryon developed before the onset of annular chambers. The Oman specimens exhibit equal-sized principal auxiliary chambers and symmetrical spirals and are assigned to N. stockari bejaensis Özcan, Boukhalfa & Scheibner, 2014, an advanced form of the N. stockari lineage. The associated alveolinids, revised in this study, rotaliids and other age-diagnostic foraminiferal taxa in the transgressive basal part of the upper member have enabled us to revise the age as middle Ilerdian (Early Eocene), assignable to SBZ 7/8 and 8; OZ 3/4. Integrating a new record of this species from Arabian Plate margin in Belen, S Turkey, and previous records from north Africa, N. stockari appears to be a diagnostic marker for the Early Eocene along the southern peri-Tethys platforms, facilitating the Tethyan correlation by orthophragminids. The palaeobiogeographic distribution of N. stockari is discussed.  相似文献