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31.
A. M. I. Osman 《Astrophysics and Space Science》1981,78(1):169-174
IIIaJ survey plates from the 1.2m SRC Schmidt have been high contrast copied in search for nebulosity at high galactic latitudes
in the vicinity of the giant radio loop II. Some filamentary nebulosity, possibly reflection, has been certainly detected. 相似文献
32.
We calculate in this paper the secular and critical terms arising from the principal part of the classical planetary Hamiltonian. This is the first step to establish a third order canonical planetary theory of Uranus-Neptune through the Hori-Lie technique. We truncate our expansions at the second degree of eccentricity-inclination. Our planetary theory is expressed in terms of the canonical variables of H. Poincaré. 相似文献
33.
Osman M. Kamel 《Earth, Moon, and Planets》1989,47(1):73-89
The construction of a third order J-S theory is presented. The Hori theory of planetary perturbations is employed. No Critical J-S terms due to the 2:5 commensurabilities and its multiples exist, when we take into account the periodic terms of order 0, 1, 2 with respect to the eccentricity- inclination. In this case the Lie series transformation degenerates and is meaningless. The J-S equations of motion for secular perturbations are solved when we neglect in our treatment, the Poisson terms of degree > 2 in the Poincaré canonical variables H
u
, K
u
, P
u
Q
u
(u = 1, 2). The Jacobi-Radau referential is adopted, and the theory is expressed in terms of the canonical variables of H. Poincaré.Now at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, U.S.A. 相似文献
34.
35.
Nurul Hawani Idris Mohamad Jahidi Osman Kasturi Devi Kanniah Nurul Hazrina Idris Mohamad Hafis Izran Ishak 《制图学和地理信息科学》2017,44(2):113-127
ABSTRACTWeb 2.0 and the proliferation of built-in Global Positioning System (GPS) on smartphones have influenced the increase of geo-crowdsourcing activities in a number of different contexts. The aim of this paper is to evaluate the performance of indigenous people’s use of mobile collection applications that are embedded in a smartphone to facilitate ecotourism asset mapping. In order to achieve this, field usability testing was conducted where structured observational method was used to assess the performance. The findings indicate majority of them can complete the data entry tasks using mobile data collection. The performance of data entries using radio button, icons, camera and audio methods were identified as better than free text and drop-down list methods. There was a correlation between the level of education with the ability of using radio button, drop-down list and image icon as data entry methods. The paper also discusses the extent of local knowledge relating to ecotourism within the community. The findings should be useful in the understanding of the design of mobile geo-crowdsourcing tools for use within other contexts that focus on data collection by semiliterate and indigenous groups. 相似文献
36.
37.
Comparative Assessment of Sludge Pre‐Treatment Techniques to Enhance Sludge Dewaterability and Biogas Production 下载免费PDF全文
Didem Okutman Tas Cigdem Yangin‐Gomec Tugba Olmez‐Hanci Osman A. Arikan Deniz I. Cifci Elif B. Gencsoy Alpaslan Ekdal Emine Ubay‐Cokgor 《洁净——土壤、空气、水》2018,46(1)
Effectiveness of ultrasonication, microwave technologies, and enzyme addition prior to anaerobic digestion is investigated using sludge samples taken from the secondary settling tank of a domestic wastewater treatment plant to improve methane production, enhance dewaterability characteristics of the sludge, and to reduce excess sludge. Microwave pre‐treatment (1500 W, 10 min at 175 °C) results in better extra digester performance (compared to the control reactor) in terms of methane production (25 m3 ton?1 suspended solids (SS)) than ultrasound (no improvement) and enzyme pre‐treatment (11 m3 ton?1 SS). While methane production is not improved as a result of ultrasonication pre‐treatment (15 000 kJ kg?1 SS), a noticeable increase (19%) is observed in the case of microwave pre‐treatment. Higher compactibility values are obtained after ultrasonication and microwave application compared to the control (i.e., from 7.1 to 8.7 and 9.2%, respectively) before anaerobic digestion. Although ultrasonication and microwave application decrease the dewaterability of the raw sludge (capillary suction time (CST) from 827 to 1364 and 2290 s, respectively), similar dewaterability results are obtained at the end of the anaerobic digestion process for all pre‐treated sludge samples. An economic assessment of this study shows that pre‐treatment with microwave results in more than 10‐fold less net cost compared to the enzyme application. 相似文献
38.
Jarrah Mohammed Ahmed Babiker Mustafa Mohammed Hariri Osman Abdullatif Gabor Korvin 《Arabian Journal of Geosciences》2017,10(6):146
This study evaluates the Late Ordovician glaciofluvial deposits of the Sarah Formation and equivalent outcroppings in north, central, and southwestern Saudi Arabia. The Sarah Formation also covers a wide area in the subsurface and is considered as an important target for unconventional tight gas reservoir. Defining the fracture types, nature, and distribution in outcrop scale might help to establish a successful fracture simulation model and behavior for the Sarah tight gas reservoir in the subsurface. This study investigates fracture characteristics for the Sarah Formation at Sarah paleochannel outcrops. The study revealed three sets of fractures, which have EW, NS, and SE-NW directions, and these fractures vary from open, resistive, and filled to resistive fractures. The closed fractures are filled with ferruginated iron oxides and gypsum. The filled fractures (the thrust boundary) are found in the study area at the SE-NW strike fracture set, while open and resistive fractures are found mainly at S-N and E-W fracture sets, respectively. The syn-depositional filled fractures (iron oxides) are considered as the younger fracture sets while the open and resistive fractures are post-depositional fractures which may have resulted from uplift or tectonic movement. A general model representing the fracture pattern and the thrusting boundaries due to glacial movement was constructed. It has been noticed that the systematic occurrence of filled fractures (thrust boundaries) described the boundaries between different glacial events, which act as a fluid barrier (filled fractures) and decrease the reservoir quality. The finding of this study might be utilized as a guide and lead for exploration in the subsurface Sarah glacial deposits. It will also help to understand and speculate the nature pattern and distribution of fractures with the Sarah Formation. 相似文献
39.
Ahmed El-Kammar Hassan Taha Abu-Zied Mohamed Galal Dina Osman 《Arabian Journal of Geosciences》2017,10(21):463
This work discusses the composition, radioactivity, and possible utilization of the kaolin resources in Sinai which are hosted in thick sandstone sequences belonging to the Carboniferous (Wadi Khaboba) and Early Cretaceous (Wadi Iseila and Abansakar) ages. The characterization of kaolin was done by microscopic and SEM examination, supported by XRD and ICP-MS analyses. The studied kaolin resources consist of kaolinite, as the main constituent, associated with subsidiary dickite and halloysite, and minor contribution of smectite and illite. The most dominant non-clay mineral is quartz, besides minor gypsum, dolomite, and hematite. Ferrugination dominates, in most cases, at the upper boundaries of the kaolin lenses, suggesting possible supergene activity. The high Al2O3/SiO2 ratio for the Cretaceous kaolin (0.54, in average) specifies its better grade relative to the Carboniferous kaolin (0.43, in average). The kaolin of the middle part of lens C in Wadi Iseila contains Si/Al molecular ratio of about unity, suggesting high-grade kaolin. The Carboniferous kaolin has enriched the radionuclides: U, Th, and Ra (at disequilibrium state due to leaching of eU relative to Ra) and the REE, relative to that of the Cretaceous age. The Carboniferous kaolin is characterized by a higher contribution of HREE (zircon signature), whereas LREE seems to be more influential for the Early Cretaceous kaolin (monazite signature). In spite of the very high CIA index (93 to 99), none of the analyzed kaolin deposits displays Ce abnormality. The high radioactivity of some Carboniferous kaolin can be a serious impediment for its utilization or its exportation. The kaolin of Sinai does not satisfy the international standards for paperwork industries and refractory manufacturing, but beneficiation may overcome this challenge. However, some lenses have high-grade kaolin with a low percentage of oxides of iron, magnesium, calcium, sodium, and potassium and a low radioactivity, hence nominated for the local refractory industry. The high-grade kaolin of Sinai fulfills the standards required for ceramics manufacturing in the global market. Grade 3 kaolin (< 30%, Al2O3) can be used in the manufacturing of white Portland cement and red glaze manufacturing on both local and global markets. 相似文献
40.
The Burdigalian mixed siliciclastic–carbonate deposits of the Dam Formation are well-exposed in Al Lidam area, in the eastern province of Saudi Arabia. They represent a shallow part of the Arabian plate continental margin. The Dam Formation is correlatable to the Miocene reservoirs in both Iran and Iraq. Therefore, studying the Dam Formation lithologic heterogeneity in a small distance with high resolution could help in further work related to pattern prediction of the Miocene reservoir properties. High-resolution sedimentological investigation was carried out through six outcrops. The facies parameters (lithology, sedimentary structures, main fossils, paleocurrent patterns and geometries of the sedimentary bodies) were described. The results revealed 15 lithofacies that have been further grouped into 7 lithofacies associations 5 of which are carbonates and include (1) interbedded dolostone and evaporates, (2) microbialite buildup, (3) ooid-dominated grainstones, (4) burrowed skeletal peloidal wackestone–packstone and (5) mollusc-dominated wackestone–packstone. The remaining two associations are of siliciclastics and include (6) intertidal siliciclastics and (7) wave-dominated siliciclastics. These lithofacies were interpreted to reflect deposition in a mixed siliciclastic–carbonate ramp system that includes subtidal, shoreface, intertidal, foreshore, supratidal and estuarine deposits in a shallowing-upward succession. Each one of these lithofacies association has distinct geometry and architecture pattern. Oolites and heterozoan lithofacies occur as sheets and show great continuity along the strike direction. Oolites pass laterally in the dip direction into more skeletal- and peloid-dominated zones, whereas heterozoan lithofacies stay continuous in the dip directions and change from siliciclastic to carbonate heterozones. In contrast, microbialite lithofacies lack continuous beds and occur as localised bioherms and biostroms. Channelised lithofacies are restricted laterally into isolated channel bodies and vertically in the contact boundary between siliciclastic and carbonate lithofacies, whereas the interbedded dolostone and evaporite lithofacies form distinct, relatively thick continuous layers. With continuous exposures in both strike (1.2 km) and dip (0.15 km) directions, the outcrops in the Al Lidam area provide unique opportunity to study the heterogeneity among lithofacies of the mixed siliciclastic–carbonate system of the Dam Formation. Such study may provide insights to predict occurrence and distribution of lithofacies bodies in their equivalent reservoirs which are important for reservoir characterisation. 相似文献