Vol. 25 Issue 4
Mahmoud Mohamed Nasralla and Abdulaziz Rashad Seroji
This study was conducted in Mina Valley and the central district of the holy city, Makkah. during the pilgrimage (Hajj) season of 1424 Hijri (2004). During this season, more than 25 million people gathered in Makkah and Mina Valley to perform the Hajj rituals. Two Mobile air pollution laboratories were used to monitor NO, NO2, NOX, non methane hydrocarbons and ozone (O3) in the atmosphere in Mina and Makkah Instruments were calibrated periodically against standard gases The present investigation showed clearly an ideal diurnal cycle of local ozone formation Although the intensity of the incoming UV radiation was the lowest compared with other months of the year, recorded ozone levels approached the maximum allowable levels of 150 micro g/m3 in Mina, and exceeded 160 micro g/m3 in Makkah during the pilgrimage period. The problem was intensified by the high recorded levels of NOx, sometimes reaching more than 800 micro g/m3, 1 h average, coupled with 1h average concentration of about 3 ppm non-methane hydrocarbons. Furthermore, the average maximum hourly ozone concentrations increased gradually from less than 60 micro g/m3 during February to reach more than 200 micro g/m3 (as an indication of smog formation) during some days of May. This coincides with the increase in the intensity of the incoming UV radiation reaching its maximum level in May. Consequently, it can be concluded that Makkah may face severe air pollution episodes when the pilgrimage season shifts to the summer months in the next few years. This may pose acute health problems for elderly people and those with respiratory health problems. Good air quality and transportation management as well as the use of alternative clean fuel are highly recommended.
Hatem Hamad
Most researches today trend to clustering in ad hoc networks as a solution to the management problem in flat ad hoc networks. Clustering aims to choose suitable nodes to lead the network ie, cluster heads When a cluster head fails, re-clustering is needed. However, this will be costly due to the characteristics of the ad hoc networks such as mobility and power exhaustion. In this research, we developed a fault tolerance mechanism to avoid re-clustering and other drawbacks that result from losing the Cluster Head (CH) A Mobile Agent (MA) will be responsible of carrying out the jobs of the CH Je, the CH will host the MA which will be the real manager of the cluster Furthermore, the closest node to the CH will be chosen as an assistant and the MA will update the assistant. Each of the CH and the assistant will have Remote Objects (RO) to communicate with each other. The main jobs of the assistant are to temporarily replace the CH when fails, then it will choose the next CH based on the clustering algorithm. Simulation results show an enhancement of the performance of using an assistant, MA and RO
Arafat Awajan
A new approach for preprocessing vowelized and un vowelized Arabic texts in order to prepare them for Natural Language Processing (NLP) purposes is described. The developed approach is rule-based and made up of four phases: text tokenization, word light stemming, words' morphological analysis, and text annotation. The first phase preprocesses the input text in order to isolate the words and represent them in a formal way The second phase applies a light stemmer in order to extract the stem of each word by eliminating the prefixes and suffixes. The third phase is a rule-based morphological analyzer that determines the root and the morphological pattern for each extracted stem. The last phase produces an annotated text where each word is tagged with its morphological attributes. The preprocessor presented in this paper is capable of dealing with vowelized and un vowelized words, and provides the input words along with relevant linguistics information needed by different applications. It is designed to be used with different NLP applications such as machine translation, text summarization, text correction, information retrieval, and automatic vowelization of Arabic text
Abdurrahman Mohamed Almadini, Abdurrahman Mohaldeen Al-Safarjalani, and Ahmed Abdulatif Al-Naeem
The study aimed at investigating the spatial variations in the quality and the chemical composition of the groundwater used in irrigation in Al-Hassa Oasis located in the Eastern Province of the Kingdom of Saudi Arabia. The main findings of the study indicated that there is a spatial variability in the salinity levels, as reflected by the values of electrical conductivity (EC), the major cations (Na+, Ca2+, Mg2+ & K+) and anions (CI, CO,2, HCO, & SO,?), and the values of the sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP). The results also showed an increasing trend from the southwest and west regions to the north and northeast borders of the Oasis. This direction is well matched with the general direction of groundwater flow in the Oasis. These spatial variations in the groundwater hydrochemical properties may be attributed to the increases for salts dissolved during the passage of the groundwater through the aquifers, increasing salinity due to extensive abstraction of the groundwater and/or due to the direct and indirect recharge occurring to the Neocene aquifer that supplies the irrigation water in the Oasis. In addition, the results indicated that the classification of the irrigation groundwater is high (C3) to very high (C4) salinity and low (S1) to medium (S2) sodicity hazard, with an overall average class of C4-S2. This suggests that the irrigation groundwater in Al-Hassa Oasis is subjected to a process of quality degradation
Mohamed Said Al-Eissa, Ahmed Rashed Al-Hamidi, and Salih Mohamed Abdulhameed Kandeal
The Arabian Sand Gazelle Males (Gazella subgutturosa marica) is one of the endangered species in Saudi Arabia. The assessment of its reproductive efficiency and semen characters have not been deeply investigated. The present study focuses on this issue, and investigates proper methods of semen dilution and freezing. The study indicated the suitability of the electro-ejaculation as a method of semen collection. Freezing of the semen at - 196°C in plastic straws (0.25ml) is the most common method for semen preservation. Two semen diluents were used; the first was a commercial diluents (Triladyl) and the other was prepared in the laboratory (Tris) diluents. When the average of individual motility before freezing was compared with that after thawing, it was found that a large number of spermatozoa was significantly (P<0.01) adversely affected by freezing. There was also significant difference (P<0.01) between individual post thawing motility of the Triladyl-diluted frozen semen and that of the Tris-diluted one during October and November. Therefore, the best results were obtained when Triladyl was used for extending the Arabian Sand Gazelle semen using freezing by liquid nitrogen rather than Tris diluents. It is recommended that the use of captive population program with cryopreservation of genetic resources bank would be suitable for the preservation and protection of the endangered species, such as the Arabian Sand Gazelle (Arabian Oryx)
Abdel Aziz Ali Al-Manni, Anwar Sheikh Alden Abdu, Nadir Abdulhameed Mohammed, and Ali Ebraheem Al-Sheeb
Doha City, the capital of the State of Qatar and its largest city, is located on the Eastern coast of Qatar. The city has been undergoing rapid growth due to increasing oil revenues leading to a sustained economic growth of the country. This was further enhanced a rapid population growth of the city from both internal migration and influx of foreign workers. The population of Doha City reached 45.6% of the total population of Qatar in 2004. During the Nineties, the State of Qatar initiated a number of infrastructural projects that included a large scale dredging and reclamation activities along the coastal areas of Doha. This research aims to use Remote Sensing (RS) and Geographical Information Systems (GIS) techniques to investigate the rapid urbanization rates and its effect on land use patterns along the coastal areas of Doha, as well as to detect the changes that took place in land use types within the city administrative boundaries. Data sources for the study included satellite images (Landsat (1) MSS dated 3/9/1972; Landsar (5) TM dated 28/2/1986; and Landsat(7) ETM+ dated 22/1/2002), field visits and surveys of the coastal areas, and information from technical reports and assessments available from Governmental Departments of Doha City. Using the landsat data, a set of thematic maps were developed to present the net increase in DOha City total area due to dredging and reclamation activities along the city coastline between 1972-2002, as well as a set of maps showing various land use categories of land use types. These included: vegetation area, vacant area, Sabkhat, Sandy area, Shallow coastal water, and Urban built area. The output of the application of GIS techniques using 1972, 1986, 2002 land use maps indicated that the net increase in the coastal areas of the city due to reclamation and dredging activities was 10 km2 during the period 1973-2002, and the changes that took place during the period 1986-2002 in the land use categories were: Vegetation (green) area decreased by about 1.6 km2, vacant area by 37.36 km2, an indication of the rapid transfer of land in Doha. On the other hand, Sabkhat area decreased by about 5.32 km2, while the urban (built) area within the established city administrative boundaries has increased by about 34.5 km2. The main recommendations of the study are the use of Remote Sensing (RS) and Geographic Information System (GIS) techniques land use changes within the city administrative boundaries, as well as the reclamation and dredging activities along coastal areas, and to use the results for future urban planning; to plan and protect the sensitive coastal ecosystems during the reclamation and dredging activities; and conducting environmental impact assessment studies for new projects and implementation of integrated coastal zone management.