Qatar Foundation Annual Research Forum Volume 2010 Issue 1

Depending on user profiles expressed by associated expected events, and conditions for raising alerts, from manual meticulous news annotation of an adequately selected corpus, an ontology domain is created. A cross-language information retrieval approach is used for automatic translation of financial documents corresponding to the particular domain corresponding to the user requirement. By this way, users may receive alerts and news expressed in their own language even if they are initially expressed in a different language. Manual annotation is used for knowledge extraction composed of general rules useful for automatic annotation of financial news arriving instantly to the system from reliable providers of information. As a first step in the loop, news are filtered, split into different sub-documents each one corresponding to a particular event and categorized. News are then mapped automatically to formatted data as instantiations of a sequence of predefined entities defined an event. By using alerting conditions given by the user, data analysis of structured tables might raise or not alerts to the user, with an adequate explanation of the cause of the alert. Automatically selected alerts initiate a new process for information generation to the user by starting a new browsing sequence of news containing events which are related to the raised alerts. Related news are recursively processed through the same structuring process in order to offer more historical data related to the alert helping the user to make decision.

The study of particle-laden coaxial, turbulent jets has been of interest due to its importance in several applications such as industrial burners, combustors and mixing devices. The addition of the second phase to the continuous phase jet can change the already complicated flow pattern and turbulent characteristics of the jets. Vast research efforts have been devoted to understanding such phenomena, but detailed investigation of particle-laden flows remains an active area of research.

The advent of laser diagnostics has helped to quantify the myriad details of the turbulent jet flow fields in great detail. However, the diagnostic tools are very expensive to use as a research tool. As a result, computational fluid dynamics (CFD) with an acceptable level of accuracy can complement the experimental results by providing additional details that are difficult to measure.

Nevertheless, even with the advancement of computational resources, modeling the turbulent characteristics remains a challenge due to its complex nature. Although recently, computational techniques have been developed to “solve” the turbulent quantities, these techniques are computationally too expensive to use in real time applications.

Hence, in this work, standard Reynolds-averaged Navier-Stokes, numerical simulations are carried out to predict the flow and turbulent characteristics of coaxial jets with and without the dispersed phase. The results are compared with the experimental data measured using molecular tagging velocimetry diagnostic technique. The key objective of this work is to investigate the flow field details that are difficult, if not impossible, to measure.

Nanoparticle image velocimetry (nPIV) uses evanescent-wave illumination to measure two velocity components, U and V, tangential to a wall in a region with thickness of the order of hundreds of nanometers. In this region the illumination intensity decays exponentially with distance normal to the wall, z, and hence tracers closer to the wall have ‘brighter’ and ‘bigger’ images than those that are further away, i.e. at larger z. Moreover, fluid velocity varies in this region with z and hence tracers at different distance from the wall move at different speeds. Furthermore, presence of the wall has a significant effect on particle distribution, and particle displacement due to local fluid velocity and Brownian displacement of particle tracers in this region. The variation in the displacement of particle images in this region, with different brightness and velocities, can bias the near-wall velocities obtained using standard correlation-based PIV method.

Artificial nPIV images of nanoparticles in a flow field with linear out-of-plane velocity profile were used in this work to investigate the impact of these issues upon the accuracy of nPIV data. Uniform and Gaussian random distribution noise were added to the images to simulate electronic noise and shot noise, respectively. The artificial images were obtained and processed for various experimental parameters to incorporate different illumination profiles, shear rates and distribution profiles. The results demonstrate that non-uniform illumination, as well as particle distribution, affects the bias in the estimated tracer velocity for the shear flow. Non-uniform intensity also affects the bias due to Brownian diffusion; however, correction for Brownian diffusion canreduce this bias error.

Cooperative communications is a technique to create a virtual antenna array using several distributed single antenna nodes in the system. It helps in increasing the area of coverage without the need of increased transmission power. As the destination receives multiple copies of the source's signal, it also improves the diversity order. The performance of cooperative networks has been thoroughly investigated in the past for various system models, protocols, forwarding techniques and fading environments.

Location estimation is another crucial process in cooperative relay networks, as it is for the other types of wireless communications networks. For instance, the range and location information can be used for network authentication, localization or cluster forming in cooperative networks. However, to the best of our knowledge, there is no study in the literature that addresses the location estimation problem in cooperative relay networks.

In this study, we investigate the performance of a cooperative relay network performing location estimation through time of arrival (TOA). We derive Cramer-Rao lower bound (CRLB) for the location estimates made using the relay network. The analysis is extended to obtain average CRLB considering the signal fluctuations in both relay and direct links. The effects of the channel fading of both relay and direct links and amplification factor and location of the relay node on average CRLB are investigated. Simulation results show that the channel fading of both relay and direct links and amplification factor and location of relay node affect the accuracy of TOA-based location estimation.

One of the most widely used measurement instruments in the turbulence community is the hot-wire probe. Amongst them, the four-wire probe is lately gaining popularity because of the enhanced accuracy and the extended directional working range due to the presence of the fourth ‘redundant’ wire. However, the need for exhaustive calibration makes the hot-wire probe a less preferred instrument to be used in atmospheric research. In the present study, development and testing of an effective data reduction scheme for a four-wire probe is reported. The robustness of the data reduction scheme enables one to obtain the same order of accuracy in measurement with reduced calibration points, and in turn reduced calibration effort. The data reduction scheme works based on the calculation of the directional sensitivity function of each wire, and then, minimization of an artificially constructed error function. Since the directional sensitivity function is smooth and continuous in space, the same order of accuracy can be obtained with less effort. In the present work, a four-wire probe was considered, and calibrated in a constant velocity jet facility. Following calibration, the data reduction scheme was applied to test the probe numerically for a random noise applied on four probes simultaneously, and the angular error was computed. The assessment of the involved accuracy of the data reduction scheme with reduced points of calibration was established.

Entity type recognition is used as a pre-processing step in common applications like summarization of text, classifying documents or automatic answering of questions posed in natural language. Here, ‘entity’ refers to concrete and abstract objects identified by proper and common nouns. Entity recognition focuses on detecting instances of types like person, location, organization, and so on. For example, an entity recognizer would take as input:

George Washington was the first President of the United States of America. and output:

George Washington was the first President of the United States of America .

The task can be performed using machine learning techniques to train a system that recognizes entities with performance comparable to a human annotator. Challenges like the lack of a large annotated training data corpus, impossible nature of listing all entity types, and ambiguity in language make this problem hard. There are existing entity recognizers which perform this task but with fair performance. One of the ways adopted to improve the performance of an existing entity recognizer is feature engineering. We initially find out which of the existing features, used in the recognizer, affect the performance most strongly. We accomplish this by adding and removing one or more features at a time from the feature list. We then use the training data to train a model and test to find out which set of features are important. The evaluation metric involves finding the precision, recall and f-score (which is the harmonic mean of precision and recall). As a next step, we add new features like word clusters and bigram word features to find out any improvements. Word clusters help when the training data does not have some words, but words belonging to the same cluster are present in the training data. This helps tagging unseen words in the test set. We also experiment with varying the size of the training data to find out how it affects the performance. Additionally, we look into Wikipedia as a source of additional features for the training data. Wikipedia has an elaborate internal link structure that can provide vital information about the category of a word. This category can be linked to a broader-sensed entity type.

The Office of Research and the Materials Technology Unit (MTU) at Qatar University (QU) have undertaken many challenges and initiatives in line with QU's role in achieving objectives set by the university's stakeholders. This includes taking the first steps to become a distinguished research university.

As materials science is an interdisciplinary field, MTU has a variety of research activities that extend across all faculties and departments, often crossing traditional subject boundaries. The materials research at MTU is linked to virtually every field of science and engineering. Our mission is to improve the development of Qatar through the discovery and development of new materials with novel properties for applications within Qatar that meet the needs of the environment, industry and society. Researchers and students at MTU are empowered to think outside the box to expand the frontiers of materials science and engineering and encouraged to help address and contribute to societal needs in strategic areas including safety, energy, economy and sustainability.

Qatar University researchers combine their expertise in materials science, chemistry, physics, biology and engineering along with advanced computation to understand and control properties of matter. MTU provides the opportunity for faculty members and students to interact with the industry and actively participate in various projects. MTU attracts leading international scholars and aims to provide universal knowledge of the four essential elements of materials science and engineering, namely: processing/synthesis, structure, properties and applications. Qatar University leads the materials research development in Qatar in sustainable materials, corrosion and nondestructive studies. MTU is starting a variety of recycling projects for polymers, papers and concrete. Materials research contributes to economic progress by developing advanced materials for new technologies, and lowering the cost and enhancing the performance of more established technologies.

The Arabian Gulf is shallow, sub-tropical and semi-enclosed, all factors that promote large variations in the properties of its water. The extreme natural variations, in association with global changes such as the increasing pH of the oceans and climate change, make the ecosystem balance of the Gulf very fragile. A one-year-long study was designed to evaluate the effectiveness of PAM (pulse amplitude modulation) chlorophyll a fluorometry in monitoring the health of sensitive ecosystems, such as coral reefs, around Qatar. The immediate objectives were: (i) to evaluate the efficacy of the PAM chlorophyll fluorometry technique as a means of assessing sub-lethal stress in corals; (ii) to calibrate and validate this technique for future ecosystem monitoring applications in this local environment; and (iii) to collect environmental data to attempt to correlate detected changes in stress status to changes in the magnitude of environmental factors that are known to affect these organisms. The study consisted of four field surveys conducted at approximately quarterly time intervals, at two monitoring stations. PAM fluorometry measurements were complemented by detailed visual assessments of the health status of the ecosystems following a traditional belt transect method, continuous recording of seawater temperature, underwater light intensity measurement and water quality monitoring.

Results of both types of observations indicated different degrees of sub-lethal stress on most of the coral species at Fuwayrit and Halul. While the visual signs of stress were difficult to quantify, the PAM fluorescence data provided a clearer indication of the stress being experienced by the organisms at the time of the surveys.

For one particular species of coral at the Fuwayrit site, PAM measurements of photosynthetic efficiency proved to be a good predictor of imminent mortality.

Based on data from the Halul site, it can be inferred that the PAM fluorometry method did not give false indications of stress for healthy corals.

This study has demonstrated that PAM fluorometry can improve our ability to monitor the health of corals in the Qatar and Gulf environment by providing objective data on the photosynthetic performances and the state of stress of these organisms.

As the State of Qatar endeavors to become the ‘Gas Capital of the World’, it is imperative to develop cost-effective technologies for gas processing. In this context, gas-to-liquid (GTL) technology represents a major pathway for the production of ultra-clean liquid hydrocarbons and value-added chemicals. The Fischer-Tropsch synthesis (FTS) reaction is the principal route for the GTL process.

Professor Bukur is exploring effects of novel and non-traditional activation (pretreatment) procedures, and promoters on performance of supported cobalt catalysts during FTS. This research is conducted in collaboration with a team of experts in both fundamental and applied aspects of catalysis. It may ultimately lead to establishing scientific basis for design of the next generation of supported cobalt catalysts for the GTL conversion process. Another area of research is development of a comprehensive kinetic model for FTS in a slurry reactor. The kinetic model developed in this study, coupled with the appropriate conservation equations and transport properties for a given reactor configuration (fixed bed or slurry bubble column), would be a valuable tool for optimizing product yield, simulating the plant design, and evaluating the economic cost benefits.

Dr. Elbashir's research activities are focused on the design of an advanced reactor technology for the FTS to leverage certain advantages over the current commercial technologies while at the same time overcoming several of their major limitations. The pillars of this innovative research approach are based on fundamental studies leading to better understanding of the complex nature of FTS, coupled with applied research work targeting the development of novel catalysts and reactors. All phases of Dr Elbashir's research activity in this field are performed in collaboration with leading scientists of multidisciplinary backgrounds and with the involvement of both graduate and undergraduate students from Qatar. This novel research approach is designed to lead to alternative FTS technologies, enabling Qatar to be on the forefront of technology development in GTL.

Qatar is a worldwide leader in liquid natural gas (LNG) production and is poised to lead the world in gas-to-liquids (GTL) production with the commissioning of the Pearl GTL facility. Unfortunately, Qatar's gas fields contain non-negligible quantities of corrosive and toxic hydrogen sulfide (H2S), resulting in the ongoing need for expensive and labor intensive pipe inspection to detect and monitor areas of corrosion. Such inspection is critical to plant integrity, worker safety, and to ensure the economic productivity of the facility. Current industry practice relies on manual sensors operated by a worker located externally to the pipe. The complex pipe geometries and sheer number of pipes, result in a sparse inspection process that forces inspectors to extrapolate measurements to large areas of the pipe network that are unseen.

To overcome these limitations, we are pursuing a radically different approach that uses an articulated robot to navigate inside the pipe, combined with a vision-based perception system that can build a detailed, registered, high resolution 3D appearance map of the inside pipe surface. By using an articulated robot, we can significantly increase the direct measurement coverage of the pipe network. By using a vision-based perception system, we can build models for visualization of the inside pipe surface that can be directly evaluated for corrosion damage. Moreover, our approach lays the foundation for automating corrosion detection by enabling changes in co-registered multi-sensor fusion (e.g. using magnetic flux leakage) to be evaluated over time.

Our work to date has focused on developing monocular and stereo visual odometry systems, which are the core component to building high resolution 3D appearance maps of the pipe surface from a robot crawler located inside the pipe. We have developed algorithms that take imagery collected from a robot moving inside the pipe, and are able to estimate the motion of the vehicle and the resulting structure and appearance of the pipe surface. We have evaluated our algorithms on pipe segments and have generated accurate, high resolution stitched images of the internal pipe surface. We will describe the details of our algorithms, current results, and next steps in our work.

The impending shortage of fossil fuels and environmental consequences of fossil fuel consumption are two of the most imperative problems in the world. This presentation is about a novel design of a solar reactor cavity system composed of a camera-like aperture and moving-wall system to house a unique thermo-fluid-chemical process known as ‘solar cracking’.

Differing from typical solar powered Rankine cycles, solar cracking uses concentrated solar energy as a heat source for direct decomposition of natural gas into gaseous H2 and particulate carbon. This process offers a CO2 emission free hydrogen production method, as the carbon is collected in a high-grade and/or nanotube form. However, solar cracking reactors have two implicit major problems:

The intrinsic losses in energy conversion efficiency as a result of the high internal temperatures and corresponding re-radiation losses as well as the inherently transient nature of the solar energy. Literature on solar reactors reveals a distinct focus on optimal reactor design for steady state efficiency, but little regarding transient inefficiencies. This presentation provides an advanced perception to solar cracking reactors by presenting you the latest results of our research at Sustainable Energy Research Lab on the design of a ‘smart solar reactor’ that is sensitive to variations in solar flux, and can adjust itself accordingly to maintain quasi-equilibrium internal conditions. A unique system design is presented featuring a solar-flux intensity sensitive aperture that can enlarge the aperture diameter when the flux is low and reduce the diameter when the flux is high.

Carbon particle deposition on the reactor window, walls, and at the exit. Carbon deposition. particularly at the exit, causes reactor clogging. There have been many innovative reactor designs aimed to achieve increased conversion efficiencies through novel flows developed at ETH-Zurich, CNRS-France, WIS-Israel, Colorado-USA, Florida-USA, and DLR-Germany. From vortex-flow to tornado, and from fluidized bed to rotating cavity, the designs of these reactors have moved toward the goal of seeking enhanced flow conditions that result in improved overall efficiencies, but have not solved the carbon deposition problem. Our latest research results at Sustainable Energy Research Lab shows that our ‘aero-shielded cyclone solar reactor’ concept provides a laminar flow shield covering the walls as a thin layer flow with a velocity that is strong enough to sweep carbon particles away. This presentation will show you the results of our research on this concept with a 3D animation of the reactor.

In view of the burgeoning market in international carbon trading and the long-term global regulatory constraints on fuel emissions, the need for an alternative to petroleum oil is both large and immediate. The primary goal of our project is to establish a global infrastructure for the production of biofuel from cyanobacteria and microalgae that can sustain economic and environmentally sound operations of the aviation industry. The business plan includes biofuel production as a driver for the development of a diverse biotechnology industry in Qatar, based on research, development, acquisition of intellectual properties, training and education. These activities are in full accordance with the 2030 National Vision for Sustainability in Qatar. The partners in this enterprise are the state airline of Qatar (Qatar Airways), the state university of Qatar (Qatar University) and the conduit for support of innovative research in Qatar; Qatar Science and Technology Park. Our research program is conceived to trigger the paradigm shift in technology that is required to make the near-term establishment of a viable biofuel technology in Qatar a reality. The program is focused on the growth, physiology and molecular biology of cyanobacteria and microalgae isolated from extreme terrestrial, freshwater and marine environments in Qatar. A diverse culture collection of photosynthetic microorganisms is now established at Qatar University and strains are currently under investigation for their utility in large-scale growth, expression of superior survival in engineered Qatar environments, amenability to novel harvesting techniques, and capacity for copious oil production.

The concept of cognitive networks has recently emerged as an efficient means for utilizing the scarce spectrum by allowing spectrum sharing between a licensed primary network and a secondary network. Cognitive networks can be divided into three different types; namely, interweave, underlay, and overlay. For the interweave type, the secondary users are only allowed to use the spectrum of the primary network whenever it is idle, which requires continuous sensing of the primary spectrum by the secondary network. For the underlay network, simultaneous transmissions are allowed by letting the secondary network share the spectrum with the primary network, under the condition of maximum interference power level allowed at the primary receiver. Finally, for the overlay type, the secondary network is aware of the signal characteristics of the primary network that are exploited to achieve an enhanced performance for the secondary network by minimizing the interference incurred by the primary transmissions.

In this poster, we present an overview of the three types of cognitive networks. We focus on the underlay cognitive network model, whereby we present the fundamental capacity results of these networks under various power constraints on both the transmit power and the interference power attained at the primary receiver. We then explore practical methods for achieving these capacity results by employing adaptive transmission techniques at the secondary users.

Environmental monitoring is an important tool in the overall environmental management strategy. In particular, a planned monitoring strategy can help in quantifying the level of impact that has occurred during country/region development and enables the predictions of potential air pollution changes to be verified. A quantitative assessment of environmental change following industrial activities is important when future environmental liabilities need to be considered. Additionally, environmental monitoring data can enable a better understanding of the processes by which impacts may arise.

Traditional environmental monitoring systems are characterized by bulky nodes, expense (in the range of USD 1 million ), and disperse (tens of kilometers) nodal allocation. Traditional systems rely on extrapolating localized measurements to project air quality information over a large geographical area. Therefore, along with the high cost, traditional networks suffer from inaccurate predications/assessment to regional mapping of air quality information, as well as non-flexible gas monitoring and selection.

As a result, many research institutes and governmental agencies worldwide are actively involved in research activities for finding more robust and cost-effective alternatives. The underlying technology for those activities is the utilization of wireless sensor networks (WSN). WSN promise to bring low cost, large scale advanced remote monitoring and automated applications to a wide range of technical areas and industries. In addition to lowering capital and operating expenses, WSN provides improved reliability, increased installation flexibility and scalability.

The project aims to architect, design, and develop an innovative solution utilizing the WSN. The solution under consideration is ubiquitous and cost effective and provides real-time data transmission and remote/online data processing and accessibility. Innovative, smaller, inexpensive and with different sensing capability, sensor nodes are integral to the solution. Such sensors are emerging, but not yet mature, and therefore substantial effort will be invested in working with sensor vendors to ensure the design and development of the right sensor nodes.

The project also includes research activities related to innovative network architecture for robustness and cost effectiveness as well as software development activities for data processing, information presentation and dissemination. This will ensure that localized and personalized information can be delivered to diverse customers.

The capture of CO2 from flue gases derived from fossil fuelled power plants and the absorption of CO2 from natural gas sweetening processes are two relevant industrial problems closely related with very important environmental, economical and technological problems that need to be solved. Porous inorganic compounds have received attention in recent years due to their possible applications in the carbon dioxide capture and storage field. In this work, we prepared new metal carbonates by reacting CO3 ^2- solution with solutions of Zn²⁺-Mg²⁺ metal ions in different stoichiometric ratios. The samples were characterized with powder x-ray diffraction analysis (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Furthermore, these samples were measured with a Rubotherm magnetic suspension balance to investigate their CO2 adsorption behavior and performance.

Laser ultrasonic inspection (LUI) is the name given to the techniques in which a laser beam interacts with the surface of a test sample and replaces piezoelectric transducers for launching and probing elastic sound waves. When this wave returns to the surface, a separate laser interferometer detects the small resulting displacement. This technique is strictly non-contact and is therefore suitable for in-process inspection of parts while at high temperature or moving at high speed. In the field of non-destructive techniques (NDT), the association of laser generation with optical detection provides a completely remote inspection system.

As this process involves hitting of high power laser beam on to the surface to be inspected and ablation of the superficial layer of the surface, one of the objections from the conventional oil and gas industry to LUI system is apprehension of potential damage or adverse effect on the surface property and integrity. This possible problem is seen as severe on pressurized pipes to the extent of being dangerous to the system.

This work attempts to present a qualification methodology which was experimentally applied to known metallic samples and with standard LUI testing conditions. Binary image processing techniques have been used with hybrid filtering and statistical measurements to quantify the findings. A relational approach is used within the digital image processing domain to qualify the extent of metal loss that occurs during a prolonged exposure of the clean metallic surface to the laser beam. A comparative study has been done on Duplex steel (UNS S31803) and Carbon steel. Samples were studied for relative metal loss, possible changes in hardness and micro-structural anomalies (if any). A new qualification method has been developed using digital image processing to approximate the damage sustained by the exposure. The results are quite promising and alleviate many doubts that conventional NDT experts may have in connection with the LUI system, especially in the oil and gas scenarios.

Life cycle assessment (LCA) is gaining wider acceptance as a method that evaluates the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment, and assesses the impact of the energy and material used and released to the environment. It is also considered as one of the best environmental management tools that can be used to compare alternative eco-performances of recycling or disposal systems.

In this study, life cycle assessments of polymer recycling are reviewed with a view to protecting the global environment and to control waste in the polymer industry in Qatar. Incremental increases in population in this region have resulted in a dramatic increase in plastic consumption and unfortunately, the waste management system has not been properly managed to date. During the study, real data from the industry was used in the analysis of the environmental impact of plastics recycling by applying the LCA methodology to the products and processes involved in recycling. The results obtained will help to understand the importance of the use of recycled polymer materials and highlight the clear advantages from an eco-efficiency viewpoint, of plastic recycling against direct manufacturing from petroleum.

During the last four decades, synthetic chemical pesticides have provided many benefits to agriculture and food production, but they pose some hazardous problems to humans, animals and environment. Chemical pesticides leave undesirable residues in food, water and the environment where they are not used properly. It is estimated that one million people are affected by chemical pesticide poisoning every year and more than 20,000 die as a result of being unaware of the risks involved in the handling or use of chemical pesticides.

This study showed that integrated pest management (IPM) was an effective alternative to synthetic chemical pesticides. The study also revealed that the components of IPM, such as cultural practices, biological control, pheromone traps, soil solarization and plant extracts provided cost effective and environmentally sound methods to control agricultural pests and diseases. As a result many growers and researchers are applying an IPM approach to maintain pest populations at levels below those causing economically unacceptable damage or loss.

In addition, this study has identified the use of IPM methods in the Arabian Gulf countries to manage some insects and diseases affecting date palm trees. The main goal of IPM is to reduce any harmful impact chemical pesticides may have on humans, wildlife, soil and water quality. The usage of chemical pesticides in the IPM programme should be rational, judicious and applied at the most vulnerable time in an insect/disease life cycle.

As part of the project studying the fundamentals of carbonate reservoir pore/fracture scale physics and chemistry within the Qatar Carbonates and Carbon Storage Research Centre at Imperial College London, sponsored by Qatar Petroleum, Shell and Qatar Science and Technology Park, we present experimental data on the dynamics of fluid-rock interaction during acid injection in carbonate rock. This has implications for CO2 sequestration in geological sinks as well as in well acidization that has been used in carbonate reservoirs to enhance oil recovery.

The effect of grain size distribution and flow rate on dissolution kinetics was studied in laboratory columns packed with calcite grains at ambient conditions. For each set of different experiments the columns were packed with 150-250µm (fine), 300-500µm (medium) and 600-850µm (coarse) calcite grains. The evolution of fluid-rock interaction was investigated by using inductively coupled plasma-atomic emission spectroscopy (ICP-AES) to study the time dependent profiles in Ca²⁺ cation concentrations inside the column and in the effluent stream. A scanning electron microscope (SEM) imaging technique was performed prior to, and after, acid injection to illuminate the nature of calcite dissolution at the rock surface.

ICP-AES and SEM analysis highlighted the complex nature of the dissolution, characterized by the creation of additional surface roughness and wormholes in single grains that resulted in the formation of a more heterogeneous porous medium. The in situ Ca²⁺ concentration, measured by slicing the column at the outlet, is greater than the effluent concentration, confirming that Ca²⁺ residesin stagnant regions of the pore space.

After starting acid injection, the chemical reaction occurs in the column, resulting in a gradual increase in Ca²⁺ concentration in the effluent that eventually reaches a steady-state value. Thus, the time needed to reach this steady state defines an important time-dependent reaction dynamics regime. The duration of this regime is longer as the grain size distribution becomes finer. As the finer media has a more complex structural heterogeneity, the corresponding surface area takes a longer time to be reached by the injected acid and the transport of the created products takes a longer time to breakthrough. This implies a transport-limited reaction.

The analysis of stable carbon and oxygen isotope composition is one of the most commonly used techniques in stratigraphic and diagenetic research of carbonate rocks. The wide-spread use and easy access of this long-established method has the side effect that little attention is paid to fundamental calibrations. Dolomite is often measured against a calcite standard (NBS19), and the acid fractionation factor used to calibrate is based on the one for calcite. To date, no reference material exists for dolomite.

In this study, which is part of dolomite research in the Qatar Carbonates and Carbon Storage Research Centre project, we focus on two main goals. First, we characterize a current standard of dolomite used for major and minor elemental geochemistry, and assess its suitability as a new dolomite standard for δ¹⁸O and δ ¹³C. Second, we attempt to better constrain the acid fractionation factor for dolomite and assess the influence of different dolomite types on this fractionation factor. As only two thirds of the total oxygen in the carbonate is released in the form of CO2 during acid reaction, a fractionation between the reacting carbonate and the resulting gas will occur. A recent study improved on the acid fractionation factors for calcite and aragonite. Often, the acid fractionation factor for dolomite is used to calculate δ¹⁸O and δ ¹³C from the values obtained by calibration with the calcite standard. Only two studies (from the 1980's) have attempted to constrain the acid fractionation factor for dolomite, of which only one did experiments not only at 25ºC, but also at 50 and 100ºC. The dataset of the latter experiment is, however, very limited and contains only two dolomite samples. We aim at improving the constraints on the acid fractionation factor of dolomite by reacting a wide range of different types of dolomite at a wide range of acid temperature, and compare this to the absolute isotopic composition of the samples measured on a fluorination line.

This work presents a new fully-unstructured meshing scheme for generating simulation meshes, coupled with a novel simulation method for fluid flow models in porous media.

We use unstructured tetrahedral meshing algorithms to generate meshes that rigorously adhere to structural and depositional heterogeneity in geological reservoir models at multiple scales. Geological heterogeneity is represented using numerous surfaces, in contrast with traditional pixel- or grid-based methods. This approach allows the generation of meshes which capture heterogeneity more efficiently and accurately than structured or partially-structured grids.

The flow simulations are performed using a new hybrid discontinuous Galerkin/control volume based method which combines continuous pressure and discontinuous velocities. Our approach rigorously enforces material balance equations while ensuring crucial scalar fields such as pressure and saturation remain positive and bounded.

This research has direct application to aquifer flow systems. We report the results of single-phase flow simulations on unstructured meshes for complex geological systems. These simulations accurately model the spread of groundwater contaminants such as methyl tertiary butyl ether (MTBE) ormetals such as arsenic that behave as tracers in aquifers.

Initially, simulations are run on simple anisotropic geological systems for two-dimensional flow to benchmark against analytical solutions and validate the accuracy of the simulator for simple flow problems. Next, simulations for tracer flow are performed on 3D channelized and fractured reservoir systems to demonstrate the robustness and accuracy of the new grids and simulator in complex reservoir geology.

We present numerical simulations of single-phase flow for a variety of geological systems of increasing complexity, culminating in systems which would be impossible to mesh and solve with structured meshes. This is also a first step towards a more complex multi-phase and multi-component implementation of the novel methods for flow through porous media.

Liquefied natural gas (LNG) carriers have played, and will continue to play, a key role in ocean gas transportation with the increasing demand for energy. Safe operation of LNG carriers requires knowledge of global and local pressures imposed by the sloshing liquid. As LNG carriers are required to operate in different environmental condition, safety is the primary consideration in such operations. LNG carriers are subjected to often significant sloshing loads during their operational life. As it moves across the ocean, the motion of the LNG carriers causes the liquid in the containers to slosh. Liquid sloshing may cause large internal stresses and deformation in the walls of containers, particularly when the external forcing frequencies of the ship are close to the natural sloshing frequencies. This effect is sometimes critical in ship design. A three-dimensional (3D) sloshing problem is analyzed by the linear wave velocity potential theory based on the boundary element method (BEM). When the rectangular tank is undergoing one-dimensional motion, the calculated results are found to be in very good agreement with other published data that assess the accuracy and applicability of the method. Extensive calculation has been made for the tank in two-dimensional (2D) motion. Then random sloshing problem, sloshing in a 3D rectangular container, is further simulated and discussed. In this case, the container filled with liquid is subjected to specified random horizontal oscillations. Both wave elevation and hydrodynamic force are obtained. The spectra of random waves and forces have also been investigated and results are compared between the analytical solutions.

Stony corals are composed of limestone structures formed by the deposits of living organisms. These are tiny animals (polyps) that live in a symbiotic relation with algae. The algae produce the food energy needed by the polyps by photosynthesis. The coral is as such a colony. Numerous colonies on shallow waters where sunrays can reach them form a coral reef. Coral reefs can be extensive, such as the Great Barrier Reef, or can form localized reefs as in Qatar. Coral reefs harbor numerous organisms including sponges, crabs, sea urchins, brittle stars and fish, and exist where environmental conditions are optimal for their flourishing, such as Southeast Asia. Malaysia is reputed as one of the best areas, where 350 coral species are known to occur.

Sea urchins and some fish are ferocious feeders on coral. Extensive feeding may cause the death and bleaching of stony corals. Climate change, in particular high sea temperature, can destroy the coral reef and excessive rains with fresh water seeping to intertidal coral reefs will also cause coral bleaching. Qatar has less than 20 species of stony coral and these are localized in only a few areas. Coastline development, including construction in the sea, is one major cause of loss of natural reefs. Aggressive fishing whether by harpoons or metal traps that are later left behind, destroy the reef. However, the recent bleaching of corals during the last decade and at present, is attributed to two factors: climate change with a rise in sea temperature (1989, 2002, 2010) and oil spills (from the Second Gulf War). Optimum growth temperature for corals is between 20^oC to 23^oC. In June 2010, the sea temperature recorded was 37.8^oC and due to this coral bleaching was observed in local reefs and as well as the death of some fish living in the reef. Bleaching was recorded in 2010 at Halul Island, Ras Rakan, Khereis, Um Alushran and Sherahou.

The results of a cockroach survey in the 14 sub-municipalities of Jeddah province revealed that a total of 3551 cockroaches were caught by 491 of 1433 traps (36.5%), from 128 of 168 houses (76.2%).

Overall, relative density ranged from 8.1 (in Obhour sub-municipality) to 43.2 (in Alaziziah sub-municipality) with an average of 21.1 cockroaches per house. It has been noticed that the population density of the cockroaches is high in the central and southern parts of the province where the sanitation and standard of living are poor.

76.4% of the cockroaches were caught in the kitchens (2712), 15.1% in rooms (537) and 8.5% in the bathrooms (302). Amongst those caught in the kitchens, the stove was found to be the most attractive habitat for the cockroaches (38.2%) followed by the fridge (16.5%), then under the sink (10.2%), in the area of the trash bin (8.1%) and finally under cabinets (3.4%). For those cockroaches caught in the bathrooms, 5.2 % (185) of them were caught under or near washing machines and 3.3 % (117) were under or near the toilet.

Surveys conducted in eight property types in the Jeddah province revealed that 1052 cockroaches were caught by 98 of 120 traps (81.7%). Overall, relative density ranged from 2.9 (in hotels) to 28.1 (in restaurants) with an average of 8.8 cockroaches per property.

All the restaurants (100%) and cafeterias (100%) were found infested by cockroaches, while 93.3% of the hospitals, 86.7% of the hotels, 80% of the groceries 73.3% of the butcheries, 66.7% of the vegetable and fruit shops and 53.3% of the bakeries were found to be infested by cockroaches.

Restaurants had the highest infestation level (40% of the total number of cockroaches trapped in all properties), while hotels had the lowest infestation level (4.1% of the total number of cockroaches trapped in all properties).

Four species of cockroaches were identified from the 14 sub-municipalities, as well as from the eight property types in Jeddah province, namely: the German cockroach (Blattella germanica L.), the American cockroach (Periplaneta americana L.), the brown-banded cockroach (Supella longipalpa F.) and the Oriental cockroach (Blatta orientalis L.) belonging to 4 genera. The German cockroach Blattella germanica was found to be the most predominant species with 98.8% occurrence in dwellings, and 97.7% in properties.

There are two widely used process control techniques for the reduction of process output variability. The first technique is automatic process control (APC) that adjusts the process using information about its current level or deviation from a desired target. The APC actions for process adjustments are achieved by the minimum mean square estimate (MMSE) controller or proportional, integral and derivative (PID) controller which minimize the output deviations from the quality target. The MMSE controller is optimal in terms of minimizing mean squared residual errors when the model and its parameters are exactly known. Whereas the PID controller is very efficient and also robust against non-stationarity due to the fact that it can continuously adjust the process whenever the data is auto-correlated. The second technique is statistical process control (SPC) which utilizes control charts. The goal of SPC for improving quality is to monitor and detect process variability, so that the special causes of the process shifting are investigated. While SPC has been successfully used in industry for identifying and eliminating the assignable cause of variations, APC techniques are widely employed in the continuous process industry to reduce common cause variations. For an improved performance of the process for the industry practitioner, both the monitoring and the adjustments of process are needed to receive the full benefit of each approach. Recently, integration of APC and SPC successfully resulted in the reduction of process output variability and improved process efficiency. In this paper, we integrate SPC and APC for various types of industries including liquefied natural gas (LNG) processes. By applying both the statistical process control and the advanced process control to a process we can dramatically improve the quality of process output. Both statistical process control and automatic process control techniques have been widely applied in industry to detect causes of variability by monitoring the key variables in the process. We investigate both techniques, their integration and methods for shift detection in the process for the monitoring of a process.