Cairo City Research Articles

Finite element model of Cairo metro tunnel-Line 3 performance

The Greater Cairo metro-Line 3, the major project of underground structure in Cairo city, Egypt, is currently under constructed. Ground movement is expected during the construction with tunneling boring machine as Cairo metro tunnel passes through sand soil.In the present study, finite element model is used to model tunnel system performance based on the case study. An elasto-plastic constitutive model is adopted to represent the soil behavior surrounding the tunnel. The effects are expressed in terms of surface displacement and soil stress change caused by tunneling. The subsoil stresses undergo three phases of change. At these phases, the loading steps of the tunnel construction are predicted using the 2-D finite element analysis.Ground movement and construction influence are obtained by the numerical model. A comparison is made between the computed tunnel performance and the observed behavior. The comparison reveals a good agreement between the calculated and the observed values.

AUTOMATIC CROWD ANALYSIS FROM VERY HIGH RESOLUTION SATELLITE IMAGES

Abstract. Recently automatic detection of people crowds from images became a very important research field, since it can provide crucial information especially for police departments and crisis management teams. Due to the importance of the topic, many researchers tried to solve this problem using street cameras. However, these cameras cannot be used to monitor very large outdoor public events. In order to bring a solution to the problem, herein we propose a novel approach to detect crowds automatically from remotely sensed images, and especially from very high resolution satellite images. To do so, we use a local feature based probabilistic framework. We extract local features from color components of the input image. In order to eliminate redundant local features coming from other objects in given scene, we apply a feature selection method. For feature selection purposes, we benefit from three different type of information; digital elevation model (DEM) of the region which is automatically generated using stereo satellite images, possible street segment which is obtained by segmentation, and shadow information. After eliminating redundant local features, remaining features are used to detect individual persons. Those local feature coordinates are also assumed as observations of the probability density function (pdf) of the crowds to be estimated. Using an adaptive kernel density estimation method, we estimate the corresponding pdf which gives us information about dense crowd and people locations. We test our algorithm usingWorldview-2 satellite images over Cairo and Munich cities. Besides, we also provide test results on airborne images for comparison of the detection accuracy. Our experimental results indicate the possible usage of the proposed approach in real-life mass events.

Apropos ‘Association of suboptimal 25-hydroxyvitamin D levels with knee osteoarthritis incidence in postmenopausal Egyptian women’

We compliment Abu El Maaty et al. [1] for their meticulous investigations to assess the incidence of vitamin D deficiency in postmenopausal women at the Rheumatology outpatient clinic at the Al-Kasr Al-Aini Medical University Hospital at New Cairo City, Egypt, and concur that randomised control trials are desirable to decide the dose schedules for vitamin D supplementation in postmenopausal women. Nevertheless, it would also be important to carry out comparable investigations at different non-academic, non-research health care centres in different Egyptian regions. Although all vitamin D estimations (as serum 25-hydroxyvitamin D) at the Al-Kasr Al-Aini Medical University Hospital were carried out employing the ‘gold standard’ technology of high-performance liquid chromatography method (HPLC), not many hospital or health care centres elsewhere would be equipped to carry out HPLC in their premises. They would have to employ commercially available enzyme-linked immunosorbent assay (ELISA) kits for serum 25-hydroxyvitamin D measurements. A beginning towards an in-house standardisation could be made in individual laboratories by picking up blood samples from cases with a high or level serum 25-hydroxyvitamin D level and to prepare its 20 aliquots. By testing such aliquots repeatedly, it would be possible to work out local mean serum 25-hydroxyvitamin D level and standard deviation (SD) [2]. Vitamin D deficiency is a global phenomenon afflicts about one billion people worldwide [3]. In resource-poor countries, with vast population of masses with vitamin D deficiency, the laboratory infrastructure is poor [4] and it would not be feasible to assay vitamin D level even by ELISA technology. Simpler, point-of-care, rapid tests are needed to quantify 25-hydroxyvitamin D level levels in the clinicians’ premises and in laboratory setup at primary health care centre laboratories. Last but not least, future plans towards vitamin D supplementation in postmenopausal women in Egypt [1] should include both vitamin D3 supplementation and a watch on post-supplementation vitamin D3 levels. A daily supplementation of 1,000 IU of vitamin D3 may fail to bring levels to a minimum of 75 nmol/l in 20–30 % cases [5].

Truthfulness of the Existence of the Pelusium Megashear Fault System, East of Cairo, Egypt

The so-called Pelusium Megashear System (PMS), consists of echelon left-lateral megashears crossing Africa from the Nile-Delta since the Precambrian times. Although this system is questioned by some scientists, its existence is sup- ported by others. This research work provides evidences for the existence of the PMS near Egypt’s capital (Cairo city). Evidence is interpreted from gravity, magnetic, and seismological data, which proves that it has been in existence since 2800 BC [1]. To support the existence of this fault zone system, all available tectonic data are reviewed; new magnetic tilt derivative TDR map and recent fault plane solution map are introduced. Moreover available earthquake catalogue for historical and recent occurrences in and around the Pelusium zone is compiled. The collected recent and historical seismicity data is supporting the existence of PMS system. The faults excluded from magnetic maps were found to be in a good agreement with tectonic and gravity data introduced by some authors. Available fault plane solutions for old and recent earthquakes gave rise to the hypothesis that the PMS is right lateral shear system. Additionally, the Pelusium zone is evaluated for the rate of seismic activity. The hazards of these zones are studied by calculating the earthquake recurrence rates using Richter-Gutenberg formula (LogN = a – bM). A statistical method is applied to exclude the effect of lack of data due to little seismograph station in the early records, or lack of population density. The Pelusium Megashear fault system proved to be active at least in Egypt, however, it plays a role only over big time window, may be thousands of years to dissipate stresses accumulated within the west of Sinai Peninsula in the African Eurasian-Arabian plates. Finally integrated tectonic model including the effect of PMS is introduced to solve the complexity of intraplate tectonics in Northern Egypt.

Islamic Politics, Street Literature, and John Stuart Mill: Composing Gendered Ideals in 1990s Egypt

Islamic Politics, Street Literature, andJohnStuartMill: ComposingGendered Ideals in 1990s Egypt Marilyn Booth In a small book sold on a downtown Cairo street in 2002, at a stall that spilled across the pavement, a dialogue between female univer sity students enacts the question of whether hijab is essential to the practice of one's faith as a Muslima, a female Muslim. In the book— as in common usage — hijab signifies modest dress, ideally (although not always) entailing loose clothing covering everything except face and hands, plus little or no use of cosmetics or conspicuous jewelry.1 The conversation among the book's characters takes place in a uni versity quadrangle and ranges across different topics, drawing on sources from history, Quran exegesis, and hadithnabawi (attributed sayings of the Prophet Muhammad) to contemporary scandal and newspaper clippings. Some of the students are muhajjabat(hijab-wear ing females) who draw books from their satchels in support of their arguments. Among them is Fatima who, along with her classmates, gradually persuades an uncovered classmate named Mayy to their argument that Islamic dress is inseparable from the correct practice of their shared faith. Mayy collapses into the arms of her muhajjabat classmates, overcome. Embracing her, they draw her away to a place of repose and contemplation for the purpose of adjusting her bodily and psychological contours to the coalescing landscape of the perfect society that can only be realized, the young women suggest, through the constant human performance of submission to the divine will. Feminist Studies39, no. 3. © 2013 by Feminist Studies, Inc. 596 Marilyn Booth 597 This book, Wajhunhila makiyaj(A face without makeup) by Muna Yunus, published in 1993 by an Islamic press in Cairo, is one of an enormous number of inexpensively printed tracts available up and down the streets of Cairo and other cities and towns in Egypt.2 At the annual Cairo International Book Fair, the largest and oldest book fair in the Arab world, Islamic-identified publishing houses are packed with customers buying such books along with embossed hardcover editions or facsimile reprints of hadith,medieval legal sources and other religious texts, often newly introduced and annotated. The dis course on Islamic practices as a basis for politics in Egypt has been accompanied for over a century by the production of manuals to guide believers in their daily lives. This literature of conduct draws on the Prophet's sunna(his example in word and deed) to enact a proper, pious life. Such popularly aimed manuals, however, focus especially on assigning specific gender roles and social spaces to women as hold ers of family and community honor. These conduct manuals and related texts are aimed at believers and elucidate the prevailing rhetoric on Islam and Islamic governance. They do so to propose the cultivation of an everyday gender activ ism in the service of visions of a modern gender order predicated on clearly defined boundaries of gendered comportment, articulated as a requirement of Islamic practice, and conveyed through a discourse reliant on Islam's foundational texts. This essay addresses three such texts among many possible candidates: the aforementioned A Face Without Makeup-, Ibrahim Mahmud's Awdatfatat (Return of a young woman), another Egyptian book focused on feminine comportment published in the 1990s; and an Arabic translation of and commentary on John Stuart Mill's The Subjection ofWomen, firstpublished in England in 1869 and in Egypt in 1998—which I also found for sale on a Cairo pavement. I examine how the framing of this translation, through the translator's lengthy introduction, contributes to local Egyptian concepts of how to be a proper Muslim woman. All products of the 1990s, these three works draw on capacious historical representation, and—in the case of Mill—bring a nineteenth-century European text into dialogue with late twentieth-century Egyptian experience. I do not suggest that these three texts are any more significant than hun dreds of similar texts available in street stalls up and down Egypt's urban landscapes. But they are indicative of an expansive, popularly 598 Marilyn Booth aimed, and easily available discourse on how to enact Islamic under standings of gender as the fabric of Egyptians' everyday lives, even as...

The early warning application role in facing the environmental crisis and disasters: "Preliminarily risk management strategy for the greater city of Cairo"

Natural disasters are inevitable and it is almost impossible to fully recoup the damage caused by the disasters. But it is possible to minimize the potential risk by developing disaster early warning strategies, methods using the new technology applications which play a crucial role in efficient mitigation and management of disasters. This paper describes the importance of the remote sensing and Geographical Information System (GIS) in evolving a suitable strategy for disaster, crises and risk management using these technologies. The main objective of this paper is to make a Preliminary risk management plan (it is a logical and systematic method of identifying, analyzing, treating and monitoring the risks involved in any activity or process. This process helps Administrations to focus on priorities and in decisions on deploying limited resources to deal with the highest risks) using the Environmental risk map of the greater city of Cairo demonstrating the most high-risk administrative areas in the city, supported by field evidence and different sources of information. to reduce the loss of life and property and protect the Nation from all hazards, including natural disasters and other man-made disasters, by leading and supporting the Nation in a risk-based, comprehensive emergency management system of preparedness, protection, response, recovery, and mitigation. This study has shown that how can the early warning Applications can be useful in analyzing, Integrating and managing different datasets for predicting the environmental crises and disasters that may affect the urbanism inside the city and help in the preparation of the Risk management plan.

Simulation of Some Air Pollutants and Weather Parameters Using WRF/Chem Model in Cairo and Qena Cities/ Egypt

Weather Research & Forecasting/ Chemistry model (WRF/Chem) has been used for simulat ion of air pollutants and weather parameters in Cairo (urban) and Qena (suburb) regions/ Egypt. Surface o zone (O3), Nitrogen o xides (NO x) and Nitrogen dio xide (NO2) as well as Wind speed (WS), Wind direction (WD) and Temperature (T) have been simu lated in Cairo. While in Qena, only (O3), (WS), (WD) and (T) have been simulated. Different predict ion performance measures have been used to assess the accuracy of estimation of these parameters. The study showed that the model can simulate the diurnal variation of ozone in Cairo better than that in Qena, although the best quantitative estimates of ozone were found in Qena. The model failed in quantitative and qualitative estimation of NOx and NO2 in Cairo as these pollutants affected directly by traffic intensity. The model estimated the weather parameters in acceptable accuracy in both Cairo and Qena especially WS and T. It is clear that WRF/ Chem model cannot generally simulate the chemical parameters in high polluted regions such as Cairo. This may be resulted fro m the coarse resolution used for the input meteorological and emission data (1 o latitude X 1 o longitude). While, it can be used safely in rural and suburban regions such as Qena. Using fine coarse resolution for meteorology and emission data may improve the results.

Interpretation of Geophysical Data at EL Fayoum—Dahshour Area, Egypt Using Three Dimensional Models

EL Fayoum–Cairo district lies in the north western part of Cairo city. It is affected by several earthquakes. According to the Egyptian Network Seismology of National Research Institute of Astronomy and Geophysics (NRIAG), the last one occurred in July 2005 with a magnitude of 4.2 in Richter scale. The Bouguer and the aeromagnetic anomaly data as well as the detailed land-magnetic survey have been subjected to different techniques of processing and interpretation to better understand the tectonic setting of the study area. For example, different kinds of filters such as 2D spectral analysis, 3D analytical signal, and Euler deconvolution techniques have been applied. Finally, the 2D modeling has been used to simulate the subsurface configuration along some selected profiles at the area. It can be noticed from the obtained results that, the seismic events (Dahshour earthquakes) are closely related to a major NNW normal fault which has a deep extension and slightly lateral displacement, in addition to its NE-conjugate faults. The recent seismic activities in the study area are directly related and/or associated with the rejuvenation of the lateral movements. Three-dimensional interpretations of the magnetic anomaly and Bouguer anomaly maps of Fayoum, Cairo province area, Northern Western Desert of Egypt have been presented. In addition, a high-resolution 3D magnetic and gravity model constrained with the seismic results reveals a possible crustal thickness and density distribution of the northern part of Egypt between the sedimentary cover and the mantel. The results reveal that the basement has an irregular surface with depths ranging from 3,600 to 5,500 m. Faults of the NNW, as well as ENE and NE directions have predominated and affected both the basement and the overlying sedimentary cover. Furthermore, the 2D modeling technique across long gravity and magnetic anomaly profiles have emphasized the basement topography and its overlying sedimentary section. The agreement between the results of gravity and magnetic surveys and geology on the other hand, confirm the reliability of the chosen constraints of interpretation.

Fatal burn injuries: A five year retrospective autopsy study in Cairo city, Egypt

Burn deaths are an important public health problem in a developing country like Egypt. The purpose of this study was to record and evaluate the causes and the magnitude of the fatal burn injuries retrospectively. An analysis of autopsy records revealed 106 (2.66%) cases of burn injuries among the total autopsies done over 5years period (2006–2010) in the mortuary of Forensic Medicine Institute, Cairo. The majority of deaths (66.1%) occurred between 11 and 50years of age group with a preponderance of males (67%). The flame burns were seen in 96.2% of the victims. The majority of burn incidents were accidental (55.7%) in nature followed by suicidal (22.6%) and homicidal (21.7%) deaths. The percentages of burns (TBSA) over 50% were observed in most of the cases (83%). Clear signs of vitality were found in 67% of the victims. The majority of deaths occurred within a week (82%) and most of the victims died from neurogenic shock (54.7%) followed by Septicemia & pneumonia (23.5%). The results of this study provide the necessary information to develop proper burn prevention programs, thereby reducing the frequency of burns and burn-related deaths.

LOW BIRTH WEIGHTS: I- MATERNAL RISK FACTORS – A HOSPITAL- BASED STUDY IN CAIRO CITY, EGYPT

Background: Low birth weight (LBW) is an important public health problem. The problem is prevalent world-wide and has negative impacts. So, its prevention is a major challenge. Objective: To determine maternal risk factors of LBW in Cairo city. Design: A case-control, hospital-based, study design. Subjects: Mothers of 270 LBW neonates were recruited in this study. A control group of mothers of an equal number of normal birth weight (NBW) neonates was chosen. Methods: The mothers of LBW and NBW neonates were interviewed using a specially designed questionnaire. All mothers had been subjected to full examinations. The neonates were weighted and examined after labor. Results: Low education, unskilled occupation, and husband unavailability are significant sociodemographic risk factors of LBW; OR=1.75, 1.62, and 2.21, respectively. Mother’s height (≤145 cm), BMI (<18 kg/m²), history of previous abortion, and maternal family history of LBW are significant personal characteristic risk factors of LBW; OR=3.26, 5.11, 3.27, and 3.23, respectively. The significant obstetric risk factors are congenital malformations, weight gain during pregnancy ≤6 kg, multiple gestations, bleeding at first/second trimester, presence of complications during delivery, gestation age <37 weeks, and birth spacing <2 years; OR=13.61, 7.61, 7.15, 5.92, 3.93, 3.17, and 2.84, respectively. Absence of antenatal care, inadequate healthy diet intake, physical hard activities, exposure to tobacco smoke, and living nearby heavy air pollution are significant health care behavioral and life-style risk factors of LBW; OR=2.49, 2.72, 2.96, 3.64, and 4.8, respectively. Anemia, hypertension, and history of recurrent chronic/specific infections are significant medical risk factors of LBW; OR=2.68, 4.35 and 4.84, respectively. Anorexia nervosa/stress, oligo/polyhydramnios, and gestational hypertension are significant gynecological/obstetric conditions risk factors; OR=3.53, 3.32, 3.23, and 3.36, respectively. Lastly, the most important risk factors of LBW as weighted by partial F-test are multiple gestations, neonate congenital malformations, weight gain during pregnancy ≤6 kg, maternal BMI <18 kg/m², gestation age <37 weeks, and mother’s weight at early pregnancy ≤45 kg, (F test=2.9, 2.7, 2.6, 2.3, 2.2, and 2.2, respectively). Recommendations: There is a need for improving the quality and utilization of ANC services, nutritional education, birth spacing, and avoidance exposure to tobacco smoke. Also, increasing promotion of reproductive health services in relation to safe motherhood at community level in order to reduce risk factors of LBW is needed. Lastly, further population based studies are needed in different areas in Egypt.

Study on the Visual Performance of a Traditional Residential Neighborhood in Old Cairo

Traditional dwellings located in the hot arid zone in Egypt are well known for their sensitive architectural response to the region's climatic conditions and socio-cultural norms. The majority of these dwellings are well recognized for their courtyard arrangement and perforated fenestration systems that evolved to control the harsh solar, climatic conditions without compromising the aesthetic quality of the space and the occupants' well-being. The unique visual characteristics of these structures cannot be fully appreciated by assessing the visual performance of buildings in isolation from their urban context. Much of the character of the traditional urban fabric of this region came from the collective visual perception of its architectural components as well as urban patterns. This paper examines daylight behavior of a well-known historic alleyway and of a courtyard house in the Old City of Cairo. Using the Radiance IES simulation modeling tool and a scaled model under an artificial sky dome, the paper investigates the visual comfort in a typical pedestrian street and a selected house. A comparative analysis between simulated results and measured values at target points was conducted. The results indicate a reasonable agreement with the simulation results. The paper gives an insight into the overall visual experience in the traditional settlements in the Old City of Cairo in relation to daylight components and hence their contribution to the unique sense of identity of the place.

Lagoons of the Nile delta, Egypt, heavy metal sink: With a special reference to the Yangtze estuary of China

Lagoons of the Nile delta are a vital aquacultural base for millions of people in Egypt. Since the 1960s, when the Aswan High Dam was completed, the estuary has changed from high to low turbidity and this has dramatically altered the eco-hydrological environment. In this study we attempt to explore the spatial and temporal distribution of heavy metals (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) based on 6 short sediment cores recovered from Manzala, Burullus and Edku lagoons on the Nile delta. Radiometric dating indicates that the upper 10–15 cm of the core sediment is post-Aswan Dam. Manzala on the eastern delta coast is severely polluted by almost all metals analyzed in the present study, especially Mn, Pb, Zn and Cd, due to its connection to the city of Cairo, and the direct human input from neighboring megacities, where the petro-chemical industry is thought to be a major source. Although Burullus on the central delta coast has the lowest concentrations of Mn and Pb, there is an increasing trend, implying a linkage to local agricultural sources, and the recently expanding megacities in the central delta plain. Edku on western delta coast seems remote from any major pollution sources, but higher Mn, Pb, and Zn in the upper portion of the lake sediment suggest human influences from Alexandria to the west via the littoral current. The horse-saddle distribution pattern of polluted metals along the Nile coast, as evidenced by the Enrichment Factor (EF), is closely associated with the regulated runoff to the lower delta plain and coast, where extremely low precipitation occurs. This physical setting is certainly prone to concentrating anthropogenic heavy metals in the lagoons. The opposite example is the intensively-cultivated Yangtze estuary in China, where monsoonal precipitation flushes out a huge amount of metals as manifested by the lower EF than that of the Nile.

PREVALENCE OF OCCUPATIONAL VOICE DISORDERS AMONG PHYSICIANS OF PRIVATE CLINICS AT MATARYIA DISTRICT, CAIRO

Introduction: Physicians use their voice in their occupation for almost the same length of time per day as professional voice users, e.g., teachers . In addition, they are also exposed to respiratory tract infections(RTI) that can cause voice problems. Aim of the work: To compare the voice disorders between private clinics’ physicians and laboratory (lab) physicians at Mataryia district, Cairo city, through the following objectives: 1- to identify the prevalence of voice problems among both groups. 2- To find out the most common voice disorders. 3- To assess the main risk factors of voice disorders. Materials and Methods: a comparative cross sectional study was implemented. The study covered the period from March to October 2012 at the Mataryia district, Cairo city. All participants have been subjected to the survey form that was used consisted of 31 questions to get information about age, gender, duration of employment, voice disorders, causes of voice disorders, daily vocal load, vocal habits, allergies, typical and atypical symptoms of gastroesophageal reflux (GER), sufficient hydration and smoking.Results: The total prevalence of voice disorders was significantly higher among private clinics’ physicians (55.6%) than lab physicians (28.9%). 34.3% of private clinics’ physicians complained voice disorders during training. Effort to talk and affecting communication were the most reported symptoms with significantly higher frequency among clinics’ physicians (100%). Female gender speaks loudly, shouts frequently, frequent throat clearing, symptoms of gastro esophageal reflux disease (GERD), smoking, allergy and insufficient hydration represented the most important risk factors for clinics’ physicians with frequent voice disorders. Conclusion and Recommendations: The prevalence of voice disorders was higher among clinics’ physicians more than lab physicians. Based on the findings, the following recommendations can be suggested: 1- health education about correct vocal technique, vocal hygiene, and additional information about diseases causing voice disorders should be included in the postgraduate medical education. 2- Increase the number of researches focus on voice problems among physicians. 3- Increase the number of physician to decrease the work load and making rest during voice problem easier. 4- Use handouts and posters to help in communication with the patients. .

The role of geophysical and seismological data in evaluating the subsurface structures and tectonic trends of Nile Delta, Egypt

In the present study, the Bouguer, aeromagnetic, and seismological data analysis for Nile Delta including the Greater Cairo region and its surroundings was used to examine and trace the tectonic framework for some deep-seated faults (mostly normal faults with a small strike–slip component) and their orientation, on which most earthquakes have occurred. The new tilt derivative (TDR) geophysical map and Euler deconvolution presented here can be used to trace the structural relationships and their depth investigations across the entire region. Generally, most of the Euler deconvolution results especially from the gravity map were well coincided with the location of contacts derived by TDR particularly NNW to NS, EW, and NE trended structures. The depths to the gravity or magnetic sources, and the locations of the contacts of density contrast were estimated. Results of the Euler deconvolution method suggested that, in the southeastern part of the area, the basement could be observed to be shallow and has become deeper beneath the northern part. Furthermore, the resulting structural map of this study is well correlated with previous geological and seismological data analyses. At least two sets of predominant faults are suspected, faults with a NNW strike (Clysmic trend) which are particularly felt in the southern portion of the Delta, and some of them give it the shape of a “graben like structure.” Another parallel set of faults, having NE–SW strike (Pelusium trend), was also obvious in the southern part between Cairo and Suez cities (at Abu Zabal area). The evaluated trending faults (NNW–SSE or NE–SW) are intersecting with predominant major WNW–ESE to E–W (Tethys trend) striking faults. These intersections may generate more additional seismic pulses and consequently increase the seismic activity for these structures. However, minor NW (Najd Fault System) is obvious in the TDR magnetic map, whereas less attendance NS (East African trend) structural trends are evident in the TDR gravity map. Moreover, it could be said that the southeastern portion of the Nile Delta (especially the eastern portion of Greater Cairo) is affected by highly tectonic fault systems. Finally, a new tectonic map was also evaluated from the resulting structural map, which helps to quantify different structural patterns (faults and/or contacts), and their relations with the regional tectonic trends are discussed.

Geotechnical properties of Egyptian collapsible soils

The risk of constructing structures on collapsible soils presents significant challenges to geotechnical engineers due to sudden reduction in volume upon wetting. Identifying collapsible soils when encountered in the field and taking the needed precautions should substantially reduce the risk of such problems usually reported in buildings and highways. Collapsible soils are those unsaturated soils that can withstand relatively high pressure without showing significant change in volume, however upon wetting; they are susceptible to a large and sudden reduction in volume. Collapsible soils cover significant areas around the world. In Egypt, collapsible soils were observed within the northern portion of the western desert including Borg El-Arab region, and around the city of Cairo in Six-of-October plateau, and Tenth-of-Ramadan city. Settlements associated with development on untreated collapsible soils usually lead to expensive repairs. One method for treating collapsible soils is to densify their structure by compaction. The ongoing study presents the effect of compaction on the geotechnical properties of the collapsible soils. Undisturbed block samples were recovered from test pits at four sites in Borg El-Arab district, located at about 20km west of the city of Alexandria, Egypt. The samples were tested in both unsoaked and soaked conditions. Influence of water inundation on the geotechnical properties of collapsible soils was demonstrated. A comparative study between natural undisturbed and compacted samples of collapsible soils was performed. An attempt was made to relate the collapse potential to the initial moisture content. An empirical correlation between California Bearing Ratio of the compacted collapsible soils and liquid limit was adopted. The presented simple relationships should enable the geotechnical engineers to estimate the complex parameters of collapsible soils using simple laboratory tests with a reasonable accuracy.

CONGESTION DUE TO TRAFFIC DESIGN AND ITS IMPACT ON FUEL CONSUMPTION AND VEHICLE EMISSIONS: A CASE STUDY

ABSTRACTWith the fast-growing economy and population, transportation has become a crucialcomponent of modern life in Egypt. Sales of road vehicles have been growing at atremendous speed over the last few years. On the other hand, the growth ofinfrastructure is however much slower than that of vehicles. This has led to severecongestion problems in the city of Cairo evidenced by very low average vehiclespeeds and high percentages of driving time in idling, acceleration and deceleration.Traffic congestion has a direct impact on quality of life in most of countries.Congestion deals with much more than just the cost of burning fuel, wasting time andcar maintenance but it affects drivers attitude, health and work performance. It isalso leading to more crashes, and air pollution. Congestion is ultimately resulting in aless productive economy and reduced quality of life for many people. Of course thereare solutions which could reduce the effect of congestions on the people’s life andthe country economy in Egypt.In the present paper facts about the cost of congestions in one of the manycongestion spots around Cairo are presented. In the present case study thecongestion is resulted from adopting one of the traffic designs in an improper place(U-turn concept). Fuel consumption, wasted time, traveled distance, are someexamples of the estimated parameters due to the congestion in 9 U-Turns whichwere chosen in one of the main streets in Cairo.

Domes in the Islamic Architecture of Cairo City: A Mathematical Approach

This work analyzes mathematically and graphically the two methods used historically in the transitional zone between the circular base of the dome and the square top of the cube where the dome is supported. The time frame of this work is the distinguished historical buildings of Islamic Cairo built between the ninth and eighteenth centuries. Ten samples were chosen out of a total of thirty. A set of mathematical expressions has been derived to relate the different parts of the squinches/pendentives to the cube with a side of length l. The equations derived were validated twice, first by generating 3D graphical sequences for both squinches and pendentives for the selected domes using CAD software based on the values obtained from the driven equations, and second by executing physical models using a 3D printer for two examples of squinches and pendentives.

Was al-Maqrīzī’s Khiṭaṭ a Khaldūnian History?

: Mu1ammad Taqiyy al-Dīn al-Maqrīzī is undoubtedly the historian with the most expansive repertoire of the entire fifteenth century Arabic historiography. His al-Mawā’iẓ wa-l-i’tibār bi-dhikr al-khiṭaṭ wa-l-āthār (abbrev. Khiṭaṭ), in particular, is a unique achievement, which manages to present a general historical discourse through the chronicling of buildings and topography. This unprecedented book, this paper argues, may have benefited from the author’s extended association with Ibn Khaldūn, the great interpreter of the notion of ’umrān (civilization, in the sense of human settlements). Ibn Khaldūn was al-Maqrīzī’s revered teacher for at least thirty years. He seems to have influenced his pupil’s thinking about the city as the domain of civilization in two ways: analytical, that is to look for causes and effects behind events and appearances, and interpretive, that is to see in the urban and architectural history of the city the illustration of the underlying civilizational cycle. In the Khiṭaṭ, al-Maqrīzī seems to have applied his master’s theory to a concrete example – the city of Cairo – and drew from it pronounced moral lessons on the decline he was observing in the Mamlūk sultanate. This is probably why the Khiṭaṭ’s influence has endured for more than five centuries: a tribute to its author’s ardent passion and filial affinity with his city and country, as well as his interpretive framework, which he probably absorbed from Ibn Khaldūn.

The Impact of the Egyptian Political Events during 2011 on Hotel Occupancy in Cairo

The Impact of the Egyptian Political Events during 2011 on Hotel Occupancy in Cairo The tourism industry is the cornerstone of the Egyptian economy generating approximately 11.4% of Egyptian GDP and providing about 12.6% of direct and indirect job opportunities for the Egyptian workforce. It is the most important source of foreign exchange earnings for the national income at 20%. Despite its importance, the tourism industry is extremely vulnerable to negative events, such as terrorism, financial crises, natural disasters and political instability. This paper investigates the impact of the Egyptian political events throughout 2011 on occupancy rates in Cairo hotels and evaluates the responses of both the hotels and the government to these events. The data on hotel occupancy was collected from Egyptian Ministry of Tourism reports and shows that the political events of 2011 had a strong negative impact on the hotel industry in Egypt as hotels in Cairo and other major cities were severely hit by these events. The occupancy rates of Cairo hotels sharply declined in comparison to the occupancy rates of 2010. Juxtaposition of the occupancy data against media reports of the political events shows that each public disturbance incident had a significant negative impact on hotel occupancy in Cairo and, as a result, hotel revenues decreased. Short-term responses of the hotels included reducing room rates and reducing expenditure by laying off staff. Alongside this the government response was to financially compensate the damaged hotels. The inadequacy and inappropriateness of these responses was evidenced by hotel occupancy remaining low throughout the year. This paper discusses the alternative strategies that the hotels and the government could adopt with a particular emphasis on ensuring the safety and security of tourist and using the media to communicate this to tourists and encourage their return to a destination which provides lessons for other crisis-hit destinations.

Optimum Alkaline Electrolyzer-Proton Exchange Membrane Fuel Cell Coupling in a Residential Solar Stand-Alone Power System

Modeling of an alkaline electrolyzer and a proton exchange membrane fuel cell (PEMFC) is presented. Also, a parametric study is performed for both components in order to determine the effect of variable operating conditions on their performance. The aim of this study is to determine the optimum operating conditions when the electrolyzer and the PEMFC are coupled together as part of a residential solar powered stand-alone power system comprising photovoltaic (PV) arrays, an alkaline electrolyzer, storage tanks, a secondary battery, and a PEMFC. The optimum conditions are determined based on an economic study which is performed to determine the cost of electricity (COE) produced from this system so as to determine the lowest possible COE. All of the calculations are performed using a computer code developed by using MATLAB. The code is designed so that any user can easily change the data concerning the location of the system or the working parameters of any of the system's components to estimate the performance of a modified system. Cairo city in Egypt was used as the place at which the output of the system will be determined. It was found that the optimum operating temperature of the electrolyzer is 25∘C. Also, the optimum coupling pressure of the electrolyzer and the PEMFC is 4 bars. The operating temperature of the PEMFC had a slight effect on its performance while an optimum current density of 400 mA/cm2 was detected. By operating the fuel cell at optimum conditions, its efficiency was found to be 64.66% with a need of 0.5168 Nm3 (Nm3 is a m3 measured at temperature of 0∘C and pressure of 1 bar) of hydrogen to produce 1 kWh of electricity while its cogeneration efficiency was found to be 84.34%. The COE of the system was found to be 49 cents/kWh, at an overall efficiency of 9.87%, for an operational life of 20 years.