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1.
Ahmed A. Melegy 《中国地球化学学报》2003,22(2):150-155
1IntroductionThecomponentsoftheenvironmentaredamagedbyagriculturalpractices.Soilslosstheirfer tilityandwaterdeterioratesduetopollution .Chemicalweatheringofmineralandsoiloccursattheinterfacesbetweentheliquidandsolidphases;consequentlythesurfaceareaandcompositionofthemineralsplayanimportantroleinthisprocess.GarrelsandMackenzie ( 1 96 7)suggestedthatincon gruentweatheringreactionswouldproducedissolvedspeciesandnewsolidsthataremorestableintheweatheringenvironmentthantheoriginalbedrockminerals.Ro… 相似文献
2.
《地学前缘》2006,(4)
(1)Dr.El-Sayed Mohamed Abdelrahman Professor of Geophysics,Cairo University,Egypt.His pri mary researchinterests are poten-tial field methods.His research has focused on gravity,magnetic,self-potential methods including depth and shape determination.He hasbeen awarded5prizes between1992and2003,including the state prize in Earth sciences,the state prize in advanced technological sciencesand the others.(2)Dr.Norman Bleistein Emeritus Professor of Geophysics,Colorado School of Mines,USA.… 相似文献
3.
Geotectonics - The new administrative capital city area in Egypt, planned to be constructed in the area between Cairo and Suez cities, is vulnerable to moderate and strong earthquakes, which are... 相似文献
4.
For studying recent crustal movements and their relation to earthquake occurrence in large scales, the National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Cairo, Egypt started in 2006 the establishment of the Egyptian Permanent GPS Network (EPGN). Beginning with 4 stations in 2007, 15 stations were operational at the end of 2011. In addition, a station in Alexandria of the French “Centre d'Études Alexandrines” (CEALX) was added as station to the EPGN. Nowadays, 16 stations are operational and an extension to 20 in the near future is expected. The collected EPGN data of the last 6 years are used in this work to throw light upon the present state of recent crustal movement of the whole of Egypt. Bernese software V. 5.0 was used for processing the collected data according to the IGS standards. In addition, selected IGS, AFREF, and EPN sites are processed for reference frame definition. In this first comprehensive analysis of the permanent network, a complete and consistent evaluation resulted in the first estimates of present day horizontal velocities and coordinate time series. 相似文献
5.
A New Kingdom spinning bowl from Karnak (Luxor) Egypt is similar in form to spinning bowls commonly found at other Egyptian sites and has a bulk chemical composition in the range for other Egyptian marl vessels. These data support a domestic origin. The matrix of the bowl contains unaltered, sand-sized, mafic rock fragments with volcanic, subophitic textures. Over 20% of the sand-sized grains consist of angular, unweathered rock fragments, and of these ∼20% are volcanic. Apparently they were added as temper. Electron microprobe analyses show that augite, plagioclase, and, where present, pigeonite, in nine of these have compositions typical of mafic igneous rocks. Geothermometry confirms crystallization at ∼1100°C. Pyroxene discrimination diagrams indicate geological sources ranging from within-plate alkali basalts to within-plate, continental tholeiites. Suitable sources for the temper are rare in Egypt. Both alkaline and tholeiitic, postorogenic (unaltered) late Cenozoic basalts occur in the Cairo area, making this the most likely but not the only possible source for the temper. The pottery may have also originated in Cairo because raw rock materials were moved upstream less commonly than down the Nile. A Cairo provenance for the Karnak artifact is consistent with the everyday movement of people and goods along the Nile between the ancient twin capitals of Memphis and Thebes. These results and the common occurrence of volcanic rocks as temper indicate that microbeam analytical techniques may help narrow the provenance of ancient pottery. © 1998 John Wiley & Sons, Inc. 相似文献
6.
Mohamed Sobaih 《Geotechnical and Geological Engineering》2011,29(3):249-258
Population increase and development plans in Egypt require the establishment of many new cities near Cairo. One of these cities
is the 15th of May City located about 30 km south of Cairo. The site of this city is very near from two quarries belonging
to two cement companies. The inhabitants used to complain from the blastings in these quarries. At a certain stage some buildings
have suffered different levels of damage. Upon the request of official authorities a study program has been performed to identify
the causes and the safety of five chosen buildings. The program included experimental testing to measure the vibration of
the chosen buildings during blasting operations. Three-dimensional structural analysis has been also performed. Results have
showed that the damage was due to Dahshour Earthquake of Oct. 12th, 1992 and not due to quarry blastings. Many other useful
conclusions have been obtained. 相似文献
7.
Bruce Frayne 《Geoforum》2004,35(4):489-505
Based on recent research in Windhoek, this paper demonstrates that it is the well established and widespread social linkages that persist between rural and urban households that are central to the ability of poor urban households to survive. Whereas informal coping mechanisms that include borrowing, piecework and credit are pervasive in rural areas of Namibia, intra-urban sources of food are poorly developed, and outside of kinship circles, social networks within Windhoek are used sparingly, even in times of greatest need. In addition, urban agriculture plays a very limited role at present in urban food supply. The research demonstrates that urban households that are most vulnerable to hunger are those that have limited social connections to the rural areas, and must rely on intra-urban opportunities to get food (including borrowing, begging, piecework and crime). The most vulnerable are female- and male-headed households with no access to farm income and limited/irregular urban incomes. In contrast, those with active rural-urban linkages enjoy significant transfers of food from rural areas that offset hunger and vulnerability in the urban context. Urban-rural reciprocity is therefore not only a one-way movement of people and resources from the urban to the rural areas, but also a transfer of food from rural to urban households. 相似文献
8.
随着城市化进程的持续推进,城市地下空间开发利用的重要性日益凸显。但各城市地下空间资源开发存在盲目性,未能与城市规划要求充分对接,亟须构建面向城市地下空间开发的适宜性评价体系。本文阐述了城市规划与地下空间开发间的关系,提出在城市规划指导下进行地下空间开发的重要性。针对不同的城市类型,需要采取针对性的探测技术,评价地质、环境、资源和技术经济等方面,并根据评价结果划分开发适宜性等级。研究认为,在城市规划指导下,运用开发适宜性评价体系,可以实现地下空间的有序可持续利用。 相似文献
9.
《Journal of African Earth Sciences》2007,47(1):1-8
The basal mudstones from the El-Nom borehole in the Gebel Abraq area in southern Egypt have yielded a diverse and relatively well preserved terrestrial palynoflora that includes Balmeisporites holodictyus, Crybelosporites pannuceus, Foveotricolpites gigantoreticulatus, Nyssapollenites albertensis, Retimonocolpites variplicatus and Rousea delicipollis. These suggest an Albian–Cenomanian age and deposition in a fluvio-deltaic environment; no marine phytoplankton is reported. The fern-dominated palynoflora and the overwhelming presence of kaolinitic clays suggest a warm, humid palaeoclimate. According to available knowledge, the mudstones in the Gebel Abraq area, equivalents of the so-called “Timsah Formation”, might be correlated with an older rock unit, the Maghrabi Formation, based on the new palynological age assessment. This new definition of local stratigraphy implies that the Bernice sheet of geological map of Egypt [Klitzsch, E., List, F., Pöhlmann, G., 1987. Geological map of Egypt, sheet NF 36 NE Bernice, 1: 500 000. Conoco and the Egyptian General Petroleum Corporation, Cairo] ought to be reconsidered. 相似文献
10.
In poor health: Supermarket redlining and urban nutrition 总被引：1，自引：0，他引：1
Elizabeth Eisenhauer 《GeoJournal》2001,53(2):125-133
Over the past 100 years, ethnic minorities and the poor have become increasingly concentrated and isolated in low-income urban neighborhoods. While the demographic changes in cities are well documented, the parallel history of urban retailing is less well known. Little research has been done on changes in urban food retailing, particularly as they concern the urban poor. As the residential character of urban neighborhoods changed during the 20th century, so did the amenities available in those neighborhoods. The low point for urban retailing was in the 1980s, when cities experienced a net loss of supermarkets even as, nationally, store openings exceeded closings. The trend toward fewer, bigger stores located outside cities has continued to the present. Some critics have referred to this disinclination of large chains to locate in cities as `supermarket redlining'. Changes in food availability are a key element in the changing social conditions of the urban poor and, as good nutrition is critical for good health, a contributing factor in the decline of urban health. This paper will examine changes in urban retail food availability, the impact these changes have had on the health status of the urban poor, strategies utilized by the urban poor to address inadequate access to quality food sources, and the role of supermarkets in distressed communities. 相似文献
11.
《Geoforum》2017
Interpersonal sharing of food has been an omnipresent feature of human civilisation from hunter-gatherer societies to the present, both as a mechanism through which sustenance is secured and as a means to cement social relations. While the evolutionary dynamism of this food sharing is relatively well documented, critical scholarship has tended to examine contemporary food sharing practices beyond family and friends through case studies of individual initiatives. A broader view of food sharing practices is absent. In addition, there has been little examination of the role that emerging information and communication technologies (ICT) are having on food sharing, despite claims that such technologies offer transformative potential to achieve more secure, sustainable and just food systems. In response, this paper presents a novel landscape level analysis of more than 4000 ICT-mediated urban food sharing activities operating across 100 cities in six continents. Adopting conceptual insights from the intersection of social and economic practice-oriented approaches, the resulting foodsharing database progresses understanding of, and makes visible, the ways in which food (and food-related skills, stuff and spaces) is being shared across diverse urban settings. To conclude, it is argued that the database plays an important productive and performative role in mapping and comparing diverse food sharing economies. Importantly, it provides a springboard for further explanatory research to fine-tune our understanding of the evolution, governance and sustainability potential of urban food sharing. 相似文献
12.
Geotechnical and geological properties of limestone samples from the Mokattam Quarry in Cairo, Egypt, were determined in order to provide prior information for the selection of suitable methods for the conservation of stone monuments around Cairo. A commercial chemical consolidant (Wacker OH 100) was applied to fill the pore spaces and to strengthen the weathered rock. Filling of pore spaces was confirmed by the decrease of both porosity and permeability of rock samples after the application of the consolidant. Analysis by mercury porosimeter showed most effective consolidation results for pore spaces from 0.75 to 1.0 µm in diameter, which were those mainly observed in the samples. Ultrasonic velocity did not show any significant evidence but an increase in strength, observed as an increase in the point load index after the consolidation process was completed, confirmed that the filling and consolidation process worked effectively. Point load testing can thus be used in preference when the number of samples available for laboratory testing is limited. From the color analysis, it was shown that there was no noticeable color change after the application of consolidant Wacker OH 100. The combinations of laboratory tests adopted in this study can be applicable to the planning of conservation of other stone monuments. 相似文献
13.
Beate Lohnert 《GeoJournal》1994,34(3):269-275
As a consequence of the last two droughts in the Sahel, in 1991 still 3,850 displaced people were living in Mopti under precarious conditions. These people represent one of the most vulnerable groups within the urban food system of Mopti being directly dependent on market mechanisms and directly affected by food price increases. But they do not form a homogeneous group, some persons or households are more affected than others.The degree of being affected by food price fluctuations is to a large extent dependent on ethnicity, gender, the number of dependants to be supported by economically active household members and the degree of integration into social networks. The state-run Food-Security-Programme as well as programmes of international development cooperation are playing a very marginal role in mitigating food insecurity in the urban context. This is mainly an effect of shortfalls in the targeting process. 相似文献
14.
Earthquake response characteristic and sensitivity of 1-Hz Global Navigation Satellite System - precise point positioning (GNSS-PPP) for a seismic response in time and frequency domains are the main objectives of this study. The Delta and Cairo areas, Egypt, experiencing the shock of the Greece earthquake occurring on April 16, 2015 (18:50 hours), is presented in this study. The results of this study reveal that the seismic wave effect is very small and can be neglected inside the Delta region and the strong motion occurred in an upward direction for the whole monitoring area. Furthermore, the time-frequency analysis illustrates the ability of the time and frequency domains to use and analyze the surface motion based on a 1-Hz sampling frequency and to detect the small- and high-strength motions of seismic waves. 相似文献
15.
《Geoforum》2013
This is a paper concerned with security, surveillance and notions of atmosphere and ambience. Whilst surveillance and security research has been excellent at examining socio-spatial relations drawn into the production and consumption of surveillance technologies, systems and practices, it has been far less well attuned to the material–affective relations, presences and absences it comes to constitute as the fabric of public space. Research within human geography and a broader ‘new materialism’ within the humanities and social sciences has become increasingly interested in exploring affective atmospheres, yet largely ignorant of a well established school of thought within French urban and social theory of ‘ambiance’. This paper explores the providence of considering atmospheres and ambiances for the examination of surveillance through the case study of two major railway stations in Britain and France. The paper proffers some methods and techniques for the further exploration of atmospheres/ambiances of security. 相似文献
16.
国内城市地下空间开发利用现状与发展趋势 总被引：1，自引：0，他引：1
我国城镇化水平不断提高的过程中,各类“城市病”是多数城市必须面对的难题,城市地下空间的开发利用成为各个城市解决这一问题的有效途径。在这样的背景下,我国城市地下空间开发利用从21世纪起进入快速发展阶段,十几年来地下空间利用增长迅猛,成就斐然。文章总结了当前我国城市地下空间各功能开发现状,并分等级叙述了我国几类城市地下空间开发利用现状。最后文章提出我国城市地下空间开发利用的趋势是向地质调查先行,网络化与分层化规划,协同化利用,内部环境生态化和人性化,管理数字化和智能化方向发展;不同城市将根据其社会经济需求和地质环境特点差异化重点开发,科学利用城市地下空间资源,发挥其社会、经济效益,让城市更美好。 相似文献
17.
About 40% of the water supply of Cairo, Egypt, is drawn from a groundwater reservoir located southeast of the Nile Delta. Several thousand shallow wells supply drinking water to the farmers from the same groundwater reservoir, which is recharged by seepage from Ismailia canal, the irrigation canal network, and other wastewater lagoons in the same areas. Sewage water lagoons were located at the high ground of the area, recharging contaminated water into the aquifer. Since the groundwater in this area is used for drinking purposes, it was decided to treat the sewage water recharging the aquifer for health reasons. In this paper a solution to the problem is presented using an injection well recharging good quality water into the aquifer. A pumping well located at a distance downstream is used to pump the contaminated water out of the aquifer. A three-dimensional solute transport model was developed to study the concentration distribution with remediation time in the contaminated zone. 相似文献
18.
An earthquake of local magnitude 5.3 (duration magnitudeM
d
) on the Richter Scale occurred at Dahshour, 18 km south of Cairo, Egypt, on Monday, 12 October 1992 at 3:09 pm (local time). Numerous aftershocks followed the main event during the following weeks with magnitude up to 4.3. The earthquake occurred in an area that has had no recent seismic activity, and affected many cities in Egypt. Many buildings and monuments were severely damaged or collapsed. Modern concrete skeletal structures suffered minor nonstructural damage. Earthquake physical damage was estimated at about one billion U.S. Dollars. The severity of the damage was mainly due to poor construction materials and detailing, aging, inferior workmanship, and inadequate maintenance. Egypt was generally considered to be an area of moderate seismic activity. In 1989, earthquake provisions were first introduced in the Egyptian Code of Practice for Reinforced Concrete Structures only. The earthquake clearly showed the urgent need for an assessment and rehabilitation program to mitigate seismic risk hazard in existing structures. In addition, future development planning, and earthquake preparedness strategies should implement lessons learned from the event. In this paper, an overview discussion about the observations from the 12 October earthquake is presented. 相似文献
19.
Cenomanian rocks of Egypt are rich in moderately to well-preserved echinoids. From the large Cretaceous echinoid collection at the Cairo Geological Museum, a total of 27 regular species, in 12 genera, eight families, six orders and two subclasses, are revised and systematically described from these strata as exposed at several localities in Egypt. One new family (Pedinopsidae), one new subfamily (Lorioliinae), one new genus (Alternocidaris) and two new species of Goniopygus, G. subaequalis (Gebel Ekma) and G. macrotuberculatus (Gebel El Minsherah), are erected. Additionally, two species of Diplopodia, D. micropyga Fourtau, 1921 and D. halperti Fourtau, 1921, are transferred to the genus Pedinopsis. 相似文献
20.
The productive restructuring process has affected more than just the economic field, because its effects have been felt on
urbanisation processes, on social relations, and on the spatial organisation of society. Starting from the ‘metapolis’ concept,
developed by Ascher (1995), we analyse the evolution of new forms of urban space in Portugal, arguing that new urban forms
generate new social inequalities and, in extreme cases, social exclusion. Portugal is a semi-peripheral country that combines
certain of the trends in social and economic organisation common to core countries, with certain trends more common in the
developing world. Thus the understanding of urban change in Portugal is a complex task, made more difficult by the rapidity
of processes since the mid 1970s. The Lisbon Metropolitan Area has been deeply affected by the productive restructuring process.
The role of economic and urban policies in the Lisbon region is discussed, and an assessment is made of certain measures aimed
at solving economic and social problems.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献