bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel and efficient relaying scheme for next generation mobile broadband communication systems
Authors: Shaqfeh Mohammad Obaidah , Alnuweiri Hussein
Published: October 2012

Relaying technologies have been designated as major new enabling technologies for next generation wireless broadband systems, such as 3GPP LTE-Advanced. The practical deployment of decode-and-forward (DF) relaying technologies as supported by the current standard is based on repetition coding, meaning that the relay regenerates the same codeword generated by the source node. This scheme is suboptimal. Nevertheless, it is preferred in practice due to its simple implementation. The optimal relaying schemes called cooperative coding are difficult to construct in practice and require heavy computation load at the receiver. Therefore, they are rarely implemented despite their prospected performance gains.

As a simple and practical alternative, we propose a novel relaying scheme that provides a superior performance similar to the advanced cooperative coding techniques, but it is less complex to implement. Our novel scheme is called "decode-partial-forward" (DPF) because its fundamental concept of operation is based on making the relay forwards one part of the source message such that the receiver at the destination node can rely on the direct channel with the source to obtain the other part of the message. The DPF scheme is based favorably on repetition coding and maximal ratio combining techniques, which are standardized techniques with low-complexity and low computation load. Nevertheless, our novel scheme performs very close to the optimal bounds for the supported rates over relaying links. More specifically, the increase in the supported reliable transmission rates (bits/sec) using the proposed DPF scheme may exceed 30% of the supported rates using the conventional repetition coding DF scheme.

Another major advantage of our proposed scheme is that it is easy to adapt flexibly based on the channel conditions of the three links of the relay channel (source-destination, source-relay, relay-destination), by adjusting the power and rate allocation at the source and relay using simple closed-form analytic formulas. Therefore, we believe that the DPF relaying scheme is an excellent option for practical deployment in the telecommunication standards due to its simplicity, adaptability and high spectral efficiency gains.
CopITS: The first connected car standard-compliant platform in Qatar and the region
Authors: Filali Fethi , Menouar Hamid , Abu-Dayya Adnan
Published: October 2012

Given the clear impact that mobility has on economical and social development, the continuous increase in the number of vehicles coupled with the increase in mobility behavior of people are creating new problems and challenges that need to be holistically addressed to ensure safe, sustainable, efficient and environmentally friendly mobility systems. Cooperative Intelligent Transportations Systems (ITS) allow the transportation infrastructure, vehicles and people to be connected wirelessly (through WiFi-like technology, 3G, etc) and contribute to solve these new challenges.

QMIC implemented a Connected Car (CopITS) platform that allows vehicles and road infrastructure to exchange, wirelessly, data packets enabling new cooperative applications for road safety (e.g. accident avoidance application), traffic efficiency (e.g. green light optimization application), and infotainment (e.g. media and data downloading). This platform implements the latest draft of the architecture developed within IEEE and ETSI and incorporates new enhancements in terms of communication protocols and mechanisms, which outperform existing ones by enhancing data transfer for vehicle-to-vehicle (V2V) and vehicle-to-infrastructure scenarios as well as the overall performance of the system. Simulation studies using an integrated communication/traffic simulator have been conducted to investigate important metrics like scalability, efficiency, and resilience of these mechanisms

Implemented system and applications have been successfully tested in-lab and demonstrated during several events in Qatar using a real car (on-board unit) and a traffic light (roadside unit). Moreover, QMIC's Connected Car platform has been successfully tested in 2011 and 2012 Cooperative Mobility Services Interoperability tests by running all mandatory test cases, which demonstrated its interoperability with the implementations of other vendors and its conformance with the standards.

We believe that QMIC's Connected Car platform is an important contribution towards putting Qatar on the world map of the "best connected countries" and being ready to host global events like the football FIFA World Cup 2022.
Performance analysis of switch-based multiuser scheduling schemes with adaptive modulation in spectrum sharing systems
Authors: Qaraqe Marwa Khalid , Abdallah Mohamed , Serpedin Erchin , Alouini Mohamed-Slim
Published: October 2012

Background and Objective:
Reliable high-speed data communication that supports multimedia application for both indoor and outdoor mobile users is a fundamental requirement for next generation wireless networks and requires a dense deployment of physically coexisting network architectures. Due to the limited spectrum availability, a novel interference-aware spectrum sharing concept is introduced where networks that suffer from congested spectrums (secondary-networks) are allowed to share the spectrum with other networks with available spectrum (primary-networks) under the condition that limited interference occurs to primary networks.

The main objective is the development of multiuser access schemes for spectrum sharing systems whereby secondary users that are randomly positioned over the coverage area are allowed to share the spectrum with primary users under the condition that the interference observed at the primary receiver is below a predetermined threshold.

Methods:
Two scheduling schemes are proposed for selecting a user among those that satisfy the interference constraint and achieve an acceptable signal-to-noise ratio level. The first scheme selects the user that reports the best channel quality while the second is based on the concept of switched diversity where the base station scans the users in a sequential manner until an acceptable user is found. The proposed schemes operate under two power-adaptive settings that are based on the amount of interference available at the secondary transmitter. In the On/Off power setting, users transmit based on whether the interference constraint is met or not, while in the full power adaptive setting, users vary their transmission power to satisfy the interference constraint.

Results:
Monte Carlo simulations were used to verify the analytical results for the multiuser secondary system in terms of average spectral efficiency, system delay, and feedback.

Conclusion:
It is shown that scheduling users based on highest channel quality increases the average spectral efficiency, but is associated with a high feedback load. However, the switched scheduling scheme significantly decreased the feedback load but at the expense of a lower average spectral efficiency. Furthermore, it is shown that transmit power techniques increase the performance of spectrum sharing systems in terms of ASE as well as decrease system delay and feedback.
Human centric system for oil and gas quality and pipeline infrastructure monitoring in Qatar
Authors: Nasir Adnan , Ekti Ali Riza , Qaraqe Khalid A , Serpedin Erchin
Published: October 2012

Background and Objectives:
Radio frequency identification (RFID) has paved the way for a plethora of monitoring applications in the field of oil and gas. Degradation in liquefied petroleum gas (LPG)/ liquefied natural gas (LNG) quality and pipe infrastructure can be a nuisance for the oil and gas industry in Qatar. Hence, a human centric cyber-physical-system (CPS) utilizing hybrid wireless technologies including RFIDs and other sensor motes can detect and prevent such hazards. CPS technique can be used for the oil and gas sector in Qatar with customized framework architecture, event detection and decision algorithms. The objective of this research is to allow maintainers and administrators to perceive and decide on top of the monitoring system to increase the performance and efficiency of the whole monitoring application.

Methods:
The sensors collect the data and send it to the base station through collaborating wireless technologies. At the base station the data is processed and algorithms were run to detect an event such as presence of moisture, abnormal pressure, temperature and defects in a pipe's infrastructure health. Human interaction will help to further refine the data for possible false alarms. Mobile applications can be used by the users/administrators to send details of a perceived event directly to the base station.

Results:
Experiments were performed on the moisture detection in Wireless Research Laboratory in Texas A&M University at Qatar. On the similar note, other sensors can also be associated with the RFIDs and their data can be relayed to the server. A framework architecture was proposed for the human centric approach of the detection and monitoring system.

Conclusion:
We propose a system where these RFID active tags with the sensors such as pressure, temperature, flow, strain etc., in collaboration with other wireless technologies, are able to send information regarding the gas quality and pipe's infrastructure health. The collaboration of RFIDs and other technologies helps us to create a smart human centric monitoring system. This will enhance maintenance and event detection such as the presence of moisture or strain on pipe's structure. It will additionally assist in the automatic adjustment of the valve's and pump's properties according to the detected events.
Interference management for multi-user cooperative relaying networks
Authors: Omri Aymen , HASNA MAZEN
Published: October 2012

Background & Objectives:
As the electromagnetic spectrum resource is becoming highly scarce, improving spectral efficiency is becoming extremely important for the development of future wireless communication systems. Integrating cooperative relaying techniques into wireless communication systems sheds new light on better spectral efficiency. By taking advantage of the broadcast nature of wireless communications, cooperative transmission can be used in improving communication reliability, and enhancing power and spectrum efficiency. Moreover, comparing to other emerging techniques that could achieve similar performance advantages, such as multiple-input multiple-output (MIMO) technique, cooperative communication is superior in hardware feasibility and deployment flexibility. The important advantages of cooperative communication make it one of the promising techniques for future wireless communication systems. Recently, many cooperative communication schemes have been included in different cellular standards, such as WiMAX and LTE-Advanced. However, the promised throughput and diversity gain may be lost in the presence of interferences, and hence, interference management is very important for exploiting the benefits of cooperation. This requires the need to find proper methods to prevent the interference problems, which is the main target of our current research.

Methods:
In this study we introduce an efficient cooperative communications scheme which maximizes the received signal-to-noise ratio (SNR) while keeping the interference levels below a certain threshold. The introduced scheme is based on two relay selection methods: max (link 2) which is based on maximizing the SNR of the second hop, and max (e2e) which aims to maximize the end-to-end SNR of the relayed link. In this method, the perfect decoding-and-forward (DF) relaying protocol is used by the relays, and the maximum ratio combining (MRC) receiver is used to combine the direct and the best selected relay links. We derive exact closed form expressions for the probability density function (PDF) of the SNR, outage probability, average capacity, and average bit error probability for the introduced cooperative schemes.

Results & Conclusion:
Simulations are used to validate the analytical results and an agreement is observed. The results confirm the advantage of the introduced cooperation schemes in enhancing the wireless communication system and in interference management.
A new generic approach for information extraction
Authors: Elloumi Samir , Jaoua Ali , Ferjani Fethi , Semmar Nasredine , Al-Jaam Jihad , Hammami Helmi
Published: October 2012

Automatic Information Extraction (IE) is a challenging task because it involves experts' skills and requires well developed Natural Language Processing (NLP) algorithms. Moreover, IE is domain dependent and context sensitive. In this research, we present a general learning approach that may be applied for different types of events. As a matter of fact, we observed that even if a natural language text containing a target event is apparently unstructured, it may contain a segment that we can map automatically into a structured form. Segments representing the same kind of events have a similar structure or pattern. Each pattern is composed of an ordered sequence of named entities, keywords and articulation words. Some generic named entities like organizations, persons, locations, dates, and grammatical annotations are generated by an automatic part of speech identification tool. During the learning step, each relevant segment is manually annotated with respect to the targeted entities (roles) structuring an event of the ontology. IE is processed by associating a role with a specific entity. By alignment of generic entities to specific entities, some strings of a text are automatically annotated. The alignment between patterns and a new text is not often guaranteed because of the writing styles diversity that may be detected in the news. For that reason, we have proposed soft matching between reduced formats with the objective of maximal utilization of pattern expressiveness. In several cases, this reduced format successfully allows the assignment of the same role to similar entities cited in the same side, with respect to some keywords or cue words. The experiment results are very promising since we've obtained 76.90 % as an average recognition rate.
A fairness-based preemption algorithm for LTE-Advanced
Authors: Khabazian Mehdi , Kubbar Osama , Hassanein Hossam
Published: October 2012

One of the radio resource management (RRM) functionalities in LTE systems, call admission control (CAC) is employed to control the number of LTE bearer requests in order to maintain the quality of service (QoS) of the admitted bearers. However, no quality guarantee can be provided due to the inherently dynamic nature of wireless communication. For example, during congestion periods when several communications experience poor channel quality or high mobility, it is highly possible that the network cannot maintain its bearers' QoS requirements. Thus, preemption schemes may be employed to alleviate the situation. As a result, resource preemption mechanism and its fairness are prominent issues as they may directly affect applications' QoS in the higher layers, as well as other network attributes such as generated revenue. In general, preemption is unavoidable in two circumstances, namely, to manage the resources among bearers when the network is overloaded as a congestion control mechanism, or, to allocate a high-priority bearer request while sufficient resources are not available.

In this study, we propose a preemption technique by which each an established bearer may be preempted according to its priority as well as the amount of extra allocated resources compared to its basic data rate. We define the contribution of each bearer in the preemption through a contribution metric with tuning parameters which is presented in the form of Cobb-Douglas production function. We compare the fairness of the proposed scheme with a traditional preemption scheme by means of two well-known fairness indices, i.e. Jain's index and min-max index. We also discuss its effect on bearers' blocking and dropping probability and the total generated revenue.

Through a simulation approach, we conclude substantial improvements in preemption fairness when compared to the traditional approach. We discuss that the proposed scheme does not affect the main performance measurements of the network, i.e. the bearers' blocking and dropping probabilities due to congestion. We also show that the preemption contribution metric can be effectively used by the service providers to vary the total generated revenue.
RAFNI: Robust analysis of functional neuroimages with non-normal alpha-stable errors
Authors: El Anbari Mohammed , Bensmail Halima , Anjum Samreen , Bouhali Othamne
Published: October 2012

One of the most ambitious goals of Qatar in the next few years is to become a country based on scientific and technical researches instead of being dependent on hydrocarbons. To this end, Qatar Foundation has established a number of high caliber universities and institutes. In particular, Qatar Computing Research Institue (QCRI) is forming a scientific computing multidisciplinary group with a focus on data mining machine learning, statistical modeling and bioinformatics. We now are able to satisfy the computational statistics needs of a variety of fields, especially of biomedical researchers in Qatar.

Functional magnetic resonance imaging (fMRI) is a noninvasive neuroimaging method that is widely used in cognitive neuroscience. It relies on the measurement of changes in the blood oxygenation level resulting from neural activity. The technique is widely used in cognitive neuroscience. fMRI is known to be contaminated by artifacts. Artifacts are known to have fat tailed distributions and are often skewed therefore modeling the error using a Gaussian distribution is not enough.

In this paper we introduce RAFNI, an extension of AFNI, which is an fMRI open source software for the analysis of functional neuroimages. We are model the error introduced by artifacts using alpha-stable distribution. We demonstrate the applicability and efficiency of stable distributions on real fMRI. We show that the alpha-stable estimator gives better results than the OLS-based estimators.
Automated essay scoring using structural and grammatical features
Authors: Hassaine Abdelaali
Published: October 2012

Automated essay scoring is a research field which is continuously gaining popularity. Grading essays by hand is expensive and time consuming, automated scoring systems can yield fast, effective and affordable solutions that would make it possible to grade essays and other sophisticated testing tools.

This study has been conducted on a dataset of thousands of English essay sets belonging to eight different categories provided by the Hewlett Foundation. Each category corresponds to the same question or problem statement. The score of each essay of the training set is provided in this dataset by human raters.

Several features have been determined to predict the final grade. First, the number of occurrences of the 100 most frequent words in English is computed in each essay. Then, the list of average scores associated to each compounding word in the training set is determined. From this list several statistical values are considered as separate feature including the minimum, maximum, mean and median values, variance, skewness and kurtosis. These statistical features are also computed for the list of average scores associated to each compounding bigram (sequence of 2 words). Moreover, each word in the essays has been tagged using the NLTK toolkit into its grammatical role (verb, noun, adverb…etc). The number of occurrences of each grammatical role has also been used as a separate feature. All those features have been combined using different classifiers with random forests generally preferred.

This system participated in the Automated Essay Scoring Contest sponsored by the Hewlett Foundation. The results have been evaluated using the quadratic weighted kappa error metric, which measures the agreement between the human rater and the automatic rater. This metric typically varies from 0 (only random agreement) to 1 (complete agreement). This method scored 0.76519 and ranked 13th out of 156 teams: http://www.kaggle.com/c/asap-aes/leaderboard.

The proposed system combines structural and grammatical features to automatically grade essays and achieves promising performance. There is ongoing work on the extension of the developed method for short essay scoring as well as grading an unseen category of essays.
Probing equation of state parameter fitting in parallel computers
Authors: Castier Marcelo , Checoni Ricardo Figueiredo , Zuber Andre
Published: October 2012

The accurate design of chemical processes depends on the availability of models to predict the physical properties of the materials being processed. Thermodynamic properties such as enthalpies, entropies, and fugacities are particularly important in this context. Most of the models to evaluate them have adjustable parameters, fitted to give the best possible representation of the experimental data available for a given substance or mixture. Depending on how much information is available, this may entail the use of hundreds or thousands of data points. As several modern thermodynamic models have intricate mathematical expressions, especially equations of state, using so many data points to fit their parameters leads to substantial computational effort. This makes it difficult to run the parameter fitting problem from different initial estimates. The consequence is that this decreases the likelihood of finding the global minimum of the objective function used for parameter fitting.

Despite the fact that current desktops and laptops are capable of parallel computations, little has been done to take advantage of their computational power for equation of state parameter fitting. The authors have recently developed procedures to that end, executed in different desktop and laptop computers, which provided speedups compatible with the number of processors available. One of the procedures is based on the conventional, sequential simplex minimization algorithm with a parallel evaluation of the objective function (SSPO approach). The other procedure is based on a modified, parallel version of the simplex minimization algorithm with a sequential evaluation of the objective function (PSSO approach). In this paper, we extend the evaluation of these procedures, executing them in the Suqoor supercomputer of Texas A&M University at Qatar, using single and multiple nodes. Because of numerical algorithm used, speedups in the PSSO approach are limited by the number of parameters to be fitted, which does not happen in the SSPO approach. On the other hand, the PSSO approach often ends at solutions with smaller objective functions, showing a greater tendency to escape local minima.
Use of emerging mobile computer technology to train the Qatar workforce
Authors: Ally Mohamed , Samaka Mohammed , Impagliazzo John , Abu-Dayya Adnan
Published: October 2012

Background:
According to the Qatar National Vision 2030, Qatar residents are encouraged to implement information and communication technology (ICT) initiatives in government, business, and education in pursuit of a knowledge-based society that embraces innovation, entrepreneurship, and excellence in education. This research project, which is funded by the Qatar National Research Fund (QNRF) under the National Priority Research Program (NPRP), is contributing to this vision by investigating the use of innovative training technology to train Qataris so that they are prepared for the 21st century workforce. Specifically, this research project investigates the use of mobile computer technology--such as mobile phones, tablet computers, and handheld computers--to train Qatar residents on workplace English so that they can become more effective when communicating in the workplace. This presentation will share the results of a preliminary study that was conducted. This project will be expanded using the "Framework for the Rational Analysis of Mobile Education" (FRAME) model (Figure 1) that describes the convergence of mobile technologies, human learning capacities, and social interaction.

Objectives:
The research evaluates the effectiveness of the mobile computer technology training and transferability to the Qatar workplace environment.

Methods:
A total of 27 trainees participated in this study. They were given a pre-test followed by the mobile learning training and then a post-test.

Results:
Overall, the learners' performance improved by 16 percent after completing the training with mobile technology. Ninety four percent of subjects said that the quality of the presentation on the mobile technology was either excellent, good, or fair. One hundred percent of subjects reported that the mobile technology helped them learn.

Conclusion:
The delivery of training using mobile computer technology was well received by learners. They liked the interactive and innovative nature of the training.
Random subcarrier allocation in OFDM-based cognitive radio networks
Authors: Ekin Sabit , Abdallah Mohamed M. , Qaraqe Khalid A. , Serpedin Erchin
Published: October 2012

Advances in wireless communications technologies (e.g., 3G, 4G and beyond) entail demands for higher data rates. A well-known popular solution to fulfill this requirement was to allocate additional bandwidth, which unfortunately is not anymore viable due to radio-frequency (RF) spectrum scarcity. Nonetheless, spectrum measurements around the globe have revealed the fact that the available spectrum is under-utilized. One of the most remarkable solutions to cope with the under-utilization of spectrum is the concept of cognitive radio (CR).

In CR systems, the main implementation issues are spectrum sensing because of the uncertainties in propagation channel, hidden primary user (PU) problem, sensing duration and security issues. Hence, the accuracy and reliability of the spectrum sensing information can be suspicious and questionable inherently. There has been no study to date that investigates the impacts of absence of spectrum sensing information in CR networks.

In this work, due to the imprecise and unreliable spectrum sensing information, we investigate the performance of an orthogonal frequency-division multiplexing (OFDM)-based (4G and beyond) CR spectrum sharing communication system that assumes random allocation and absence of the PU's channel occupation information, i.e., no spectrum sensing is employed to acquire information about the availability of unused subcarriers or the PU's activity.

The results show that due to the lack of information of the PUs' activities, the SU randomly allocates the subcarriers of the primary network and collides with the PUs' subcarriers with a certain probability. The number of subcarrier collisions is found to be following hypergeometric distribution. The SU's capacity with subcarrier collisions is employed as a performance measure to investigate the proposed random allocation scheme for both general and Rayleigh channel fading models. To avoid the subcarrier collisions at the SUs due to the random allocation and to obtain the maximum sum rate for SUs based on the available subcarriers, an efficient centralized sequential algorithm is proposed and analyzed.

The performance of such a communication set-up can provide various insights into the studies in the CR literature, and it these be utilized as a valid candidates for performance comparison benchmarks in CR spectrum sharing systems with the availability of spectrum sensing information.
Variations in giving directions across arabic and English native speakers
Authors: Gedawy Huda , Ziadee Micheline , Sakr Majd
Published: October 2012

This work explores the differences in direction-giving strategies between two groups, native Arabic and native English speakers. This study will help influence design decisions for multi-lingual, cross-cultural human robot interaction.

There are clear cultural influences on modes of communication. Previous research studies found that direction-giving techniques and strategies vary between different cultural groups. Burhanudeen compared Japanese and English native speakers and found that locator remarks are more frequently used by Japanese natives, while the use of directives is more common with English natives.

In this work, we examine the discourse for navigation instructions of members of two target groups, Arabic native speakers and English native speakers. We address the following questions: How do languages and strategies used for providing directions vary between these two groups? What are the differences and what are the similarities? Are there any possible gender-related differences in giving directions?

We recorded 56 participants giving oral direction instructions for three specific locations at the Carnegie Mellon Qatar campus, and 33 participants giving oral direction instructions for three different locations at the Student Center. We transcribed the audio recordings and annotated our transcriptions. We categorized the spatial perspectives used by participants into route perspective which involves the use of left/right turns and landmarks, and survey perspective, which involves the use of units (time and distance) and cardinals (north, south, east and west). Our analysis also included number of pauses, repetitions, error corrections, number of words and intermediate details.

Our results showed that the way-finding strategy favored by English natives and Arab natives is the landmark-based navigation strategy. However, English natives had a higher frequency of using cardinals, pauses and intermediate information while Arab natives used units of distance, left/right turns and error corrections more frequently than English natives. Male participants from both groups are more likely to rely on survey perspective than female participants. Based on these results, we conclude that culture, language, and gender influence a speakers discourse and strategy for giving directions.
Efficient parallel implementation of the SHRiMP sequence alignment tool using MapReduce
Authors: AlSaad Rawan , Malluhi Qutaibah , Abouelhoda Mohamed
Published: October 2012

With the advent of ultra high-throughput DNA sequencing technologies used in Next-Generation Sequencing (NGS) machines, we are facing a daunting new era in petabyte scale bioinformatics data. The enormous amounts of data produced by NGS machines lead to storage, scalability, and performance challenges. At the same time, cloud computing architectures are rapidly emerging as robust and economical solutions to high performance computing of all kinds. To date, these architectures have had limited impact on the sequence alignment problem, whereby sequence reads must be compared to a reference genome.

In this research, we present a methodology for efficient transformation of one of the recently developed NGS alignment tools, SHRiMP, into the cloud environment based on the MapReduce programming model. Critical to the function and performance of our methodology is the implementation of several techniques and mechanisms for facilitating the task of porting the SHRiMP sequence alignment tool into the cloud. These techniques and mechanisms allow the "cloudified" SHRiMP to run as a black box within the MapReduce model, without the need for building new parallel algorithms or recoding this tool from scratch.

The approach is based on the MapReduce parallel programming model, its open source implementation Hadoop, and its underlying distributed file system (HDFS). The deployment of the developed methodology utilizes the cloud infrastructure installed at Qatar University.

Experimental results demonstrate that multiplexing large-scale SHRiMP sequence alignment jobs in parallel using the MapReduce framework dramatically improves the performance when the user utilizes the resources provided by the cloud.

In conclusion, using cloud computing for NGS data analysis is a viable and efficient alternative to analyzing data on in-house compute clusters. The efficiency and flexibility of the cloud computing environments and the MapReduce programming model provide a powerful version of the SHRiMP sequence alignment tool with a considerable boost. Using this methodology, ordinary biologists can perform the computationally demanding sequence alignment tasks without the need to delve deep into server and database management, without the complexities and hassles of running jobs on grids and clusters, and without the need to modify the existing code in order to adapt it for parallel processing.
Artificial ground water recharge using treated wastewater effluents
Authors: Hamoda Mohamed , Daerish Mohamed , Mohtar Rabi
Published: October 2012

Water-related problems are increasingly recognized as one of the most immediate and serious environmental threats to mankind. In particular, all the GCC countries being located in an arid region, suffer from lack of natural freshwater resources. Groundwater is the major source of water for irrigation in these countries. The groundwater aquifers contain either fresh or brackish waters. In countries like Kuwait and Qatar the groundwater available is mostly brackish. Agricultural development has put great pressure on groundwater resources and resulted in varying degrees of depletion and contamination as the demand for water has been increasing due to population growth and economic development. Over-pumping of groundwater has compounded water quality degradation caused by salts and other pollutants. In addition, saltwater intrusion is caused by over-abstraction of coastal aquifers. Meanwhile, the GCC countries are also facing changes in climatic conditions, such as rainfall patterns which affect the water cycle and limit natural groundwater recharge. The states of Kuwait and Qatar share almost similar problems and adopt the same approach in the management of their water resources under a severe stress of absence of natural freshwater resources. In these countries, wastewater collection serves almost all the population and tertiary wastewater treatment has been the common practice. Treated wastewater reuse is considered with proper attention to sanitation, public health and environmental protection. This paper will present a detailed evaluation of groundwater recharge using tertiary-treated or advanced (reverse osmosis) -treated wastewater. Recent advances, challenges, and future arrangements are discussed. A case study in Kuwait and an ongoing study in Qatar will be presented which includes advanced wastewater treatment comprising ultrafiltration and reverse osmosis systems, followed by the artificial recharge of the treated water into a groundwater lens. A simulation model is developed based on hydrogeological studies in which the augmentation of groundwater resources would provide water storage, and prevent depletion and deterioration of the groundwater. Hence, long-term sustainable groundwater management could be achieved.
Total and QP's joint acid stimulation research program to improve productivity from Qatar's oil and gas fields
Authors: Goedeke Stefan , Al Sammarraie Mohammed , Amir Ahmed Moustafa , Al-Shahwani Saqer Abdulla , Al-Mohannadi Nasser , CHENEVIERE Pascal , JULIEN Philippe
Published: October 2012

In a first ever joint venture initiative, Qatar Petroleum has joined forces with Total in an effort to improve acid stimulation programs. Acid stimulation in carbonates can greatly increase well productivity. Near-wellbore impairment or formation damage is typically analysed by a term called skin factor. It is this 'skin' that is removed during an acidizing operation in a well. Typically, reducing the skin factor by a factor of 5 can increase a well's productivity by up to 50 percent (Furui et al. 2003). Acid stimulations performed in Qatar on 23 offshore wells in 2008-2009, increased oil production by 100 percent while at the same time reducing the water cut by 10 percent. In this joint venture project conducted by researchers and engineers from Total and Qatar Petroleum, the study is divided into three phases which also includes knowledge transfer and training. Phase 1 consists of core-flooding under reservoir conditions using standard acid recipes on outcrop and field cores. In Phase 2, improved or novel acidizing systems will be tested using a dual core setup, allowing the study of acid diversion from high permeability zones to low permeability zones. The objective here is not only to improve acidizing efficiency but also to mitigate the water production from heavily watered-out zones. Modeling activities will be undertaken to design acid stimulation treatments using results from the laboratory experiments. Phase 3 involves knowledge sharing and training on mud cake removal treatments. Mud cake is the damage caused to the near-wellbore, i.e., the interface between the reservoir matrix and the well, during the drilling of open hole wells. The knowledge gained will be implemented in both onshore and offshore fields as part of acid stimulation field trials.
Development of laboratory flow-through system for Arabian Killifish embryo toxicity test
Authors: Saeed Suhur , Al-Naema Nayla , Febbo Eric
Published: October 2012

Background:
The use of fish embryos for toxicity testing (FET) is under consideration as an alternative to traditional acute fish toxicity tests. For the past two years, a marine fish embryo test (mFET) has been under development in our laboratory as a routine ecotoxicological test for risk assessment of potential contaminants around the Qatari coastal area.

Objective:
The objectives of this study were to: a) develop and use a flow-through system to optimize the mFET test conditions to maintain stable concentration of volatile compounds; b) correlate the flow-through mFET to the conventional acute fish test; c) investigate changes in sensitivity of Arabian Killifish embryos to toxicity of chlorine-produced oxidants under flow-through conditions compared to the previous static mFET.

Methods:
The flow-through system was carried out using custom designed glass chambers. Peristaltic pumps were used to ensure constant flow conditions. To investigate the effect of the flow-through mFET on toxicity of chlorine, fertilized eggs were exposed to aqueous concentrations of calcium hypochlorite for up to 240 hours. The investigated endpoints included; coagulated eggs, somite development, heartbeat, tail detachment, hatchability and post-hatch mortality.

Results:
The present investigation demonstrated that the custom designed flow-through system enhanced the FET conditions compared to the static FET. The flow-through system stabilized chlorine concentration and provided a larger volume which allowed an increase in the number of test embryos and sufficient test media for chemical analysis.

Conclusions:
Our data showed that the flow-through system improved the mFET assay for conditions like control survivability and for the main goal of bringing the sensitivity of the embryos into alignment with published data on the effects of chlorine-produced oxidants. This dataset, in conjunction with our previous work on static test conditions provides a wider range of applicability for the assay. In order to further support the mFET as an alternative to acute fish testing, the flow-through FET is currently being extended to other potential compounds of interest.
Use of microsensors and geostatistics for air quality mapping in Doha
Authors: Suliono Andi , Sadois Claude , Jeannee Nicolas , Abou-Malli Khalid , Mohamed Fadi , lemarchand Ophelie
Published: October 2012

Addressing challenges in design of effective air quality (AQ) monitoring network is important to ensure quality and representativeness of collected AQ data. Ideal locations for a network of fixed AQ stations are difficult to determine in Doha owing to the unavailability of existing AQ data, and uncertainties associated with the AQ site representation.

This paper is intended to demonstrate the use of an emerging nano- technology (micro-sensor) and geostatistic tool to map ambient air quality for oxidising gases of NO2 and ozone. Micro-sensor is a small self-adequate device that can be easily deployed in area with a difficult access, limited infrastructures or where fixed AQ stations are unavailable. In this specific study, no AQ data from fixed stations was readily available to initiate the mapping, so it was decided to use micro-sensors to provide an estimation of the AQ baseline data within Doha and was intended as a tool to understand the locations to be targeted, in priority, for future wider AQ monitoring network. A small number of micro-sensors were selected and deployed over Doha, covering different type of locations: dense urban, residential, industrial, public parks and suburb areas. After analysis of the collected data, each location was assigned with a typical AQ profile.

The use of geostatistics tool enabled us to highlight the spatial relationships between sampling points. By using appropriate interpolation algorithm (kriging, co-kriging) as well as the relevant auxiliary input data, production of AQ maps was prepared from a small number of sampling points. As the study area was limited within Doha and the microsensors specifically measured NO2/O3 concentrations, the focus areas were related to traffic emissions. Integration of geographic information related to traffic, such as road network layout and traffic density showed the influence of traffic emissions to local ambient air quality and contributed to refine the AQ maps.

This study was a valuable contribution to the wider scope of air quality monitoring project undertaken by QEERI and TOTAL, in which it provided a preliminary insight to the optimized design of a complete monitoring network, in terms of actual sampling locations and number of devices.
Next generation polymer electrolyte membrane fuel cells
Authors: Agnihotra Narendra Kumar
Published: October 2012

Polymer electrolyte membrane (PEM) fuel cell technology is one of the most promising alternative energy systems for an environmentally friendly, sustainable energy economy. Among the various types of fuel cells, PEM fuel cells are expected to be a dominant technology in the near future because they can operate with various types of energy carriers including hydrogen, ethanol, and methanol, run at relatively low temperatures (~80ºC). Fuel cells are suited for automotive applications where quick startup is required and can vary their output quickly to meet changes in power demand. Polymer electrolyte-based fuel cells require an expensive platinum (Pt) catalyst, which raises the cost of the fuel cell. PEM fuel cells can be cost effective to eliminate undesired chemical reactions during operation and to prevent degradation in performance over time however, new breakthroughs in fundamental materials technologies are essential. Nanoscale science and technology offer new opportunities to develop novel catalyst-electrode structures with dramatically improved performance. The review paper presents a new nanostructured PEM fuel cell electrode design comprised of a single layer carbon-free catalyst nanorods array with extremely low Pt loadings, controlled porosity, ideal alloy compositions, and with preferred crystal orientations for enhanced oxygen reduction. Glancing angle deposition (GLAD) process can be used for the growth of nanorods array for low Pt loading electrodes. Novel catalyst materials can significantly enhance the electrochemical reaction in fuel cell electrodes and as a result will reduce the amount of hydrogen needed for long-range transportation which would be highly desirable.
Numerical modeling of thermal plume and residual chlorine fate in Qatar's coastal waters
Authors: Febbo Eric , Kolluru Venkat , Prakash Shwet
Published: October 2012

A 3-dimensional hydrodynamic model was developed and calibrated to simulate the thermal mixing zone and predict the fate of residual chlorine and chlorination by-products (CBP) from industrial cooling water discharged from Ras Laffan City. This model is novel since the individual and cumulative effects of cooling water discharges from several outfalls are estimated in a single simulation instead of requiring separate model runs for each outfall.
The concept of incremental temperature rise (increase over the natural water temperature in the absence of outfall) was used to evaluate mixing zone plume dimensions. A probability-based computational methodology was developed to define the thermal plume mixing zone for the shallow coastal environment, which is influenced by strong tides and winds. A new boundary condition was introduced to address existing, ongoing and proposed breakwaters and structures without altering the model grid system while preserving the same boundary conditions for various management scenarios.
In comparison to freshwaters, little is known about the formation of CBP in saline waters. Therefore, a comprehensive study was devised that included laboratory experiments to quantify the kinetics of residual chlorine loss and subsequent formation of CBP in seawater as well as extensive field data collection and testing of Arabian Gulf seawater samples for chlorine and CBP in the vicinity of the discharges. Equations to describe site-specific chlorine reactions were developed to replicate observations. This empirical approach takes into account the complexity of the reactions between organic precursors and chlorine, which usually involve several parallel pathways leading to a great variety of CBP formation products. This complexity makes it difficult to develop more generic models for simulating CBP formation. Analysis of lab and field data obtained in this study have enabled calibration of a site-specific numerical modeling tool that can be used to study transport and fate of various constituents in the coastal area.
Characterization of Qatari untreated and treated male and female date palm leaves
Authors: AlMaadeed Mariam , Kahraman Ramazan , Khanama P. Noorunnisa , Al-Maadeed Somaya
Published: October 2012

This paper describes for the first time the difference in species reactions to the treatment type of date palm fiber.

Male and female date palm leaves from two different cultivars--Sheshi female and unknown male--have been considered. Characterization was done for both untreated and NaOH-treated date palm leaves by infrared spectroscopy, thermo gravimetric analysis and scanning electron microscopic techniques. These leaves were treated with different concentrations of NaOH, 0.5, 1, 2 and 5% (w/w). The results from this investigation indicate that female leaves have better tensile properties, which deteriorate with the increase of their alkalinity. The male leaves have lower tensile properties than female leaves, and their mechanical properties are improved slightly through NaOH treatment. Female leaves have more pores than male leaves. This was proven and calculated by image analysis. Untreated female leaves have higher thermal stability (353°C) than male leaves (343°C). Both can be used as cheap and environmental reinforcements in thermoplastic matrix materials whose processing temperatures are below 300°C.