bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced autonomous gas leak detection techniques
Authors: Abdel-Moati Hazem Mohamed
Published: October 2012

Background:
Existing technologies for detecting gas releases in oil and gas facilities include point and path detectors and leak detection and repair (LDAR) programs. Large networked arrays of point and path detectors are needed to detect gas leaks in oil and gas facilities due the inherent passive nature of these stationary technologies that require gas plume to come in contact with or within the line of sight the detectors. LDAR programs are not fully automated and require surveying millions of nodes in given plant to detect possible leaks. A potential solution to these challenges is a remote gas detection tools that could actively search for and autonomously detect gas leaks while removing the human component from the equation.

Objectives:
ExxonMobil Research Qatar is undertaking research to develop a Remote Gas Detection (RGD) system that will autonomously scan for and identify hydrocarbon gas leaks / emissions on a continuous basis. The system utilizes existing infrared (IR) detection technologies and expands its use to techniques that do not require human involvement. Prompt, efficient detection of gas leaks could significantly reduce fugitive emissions to the environment and provide early warning to operations personnel improving safety.

Results:
This research effort has led to the development of a sophisticated RGD system that is equipped with artificially intelligent software algorithms that can distinguish hydrocarbons from other IR hotspots in the scene with minimal false alarms. Early research activities included testing multiple RGD prototypes that integrated different IR camera technologies paired with various types of deployment strategies. Successful field tests were performed in late 2011 and led to the initiation of a short-term prototype field deployment in early 2012. Extensive libraries of IR videos, that highlight the behavior of the intelligent algorithm and the efficiency of the detection capability in varying environments, have been developed. This research effort has yielded two patent applications for novel and innovative developments in the field of remote gas detection. Future work includes evaluating system components and optics to facilitate efficient development of the first fully operational system, and continuation / expansion of the scope of pilot projects for long-term field testing.
An innovative approach for commercial utilization of saline-arid lands
Authors: Khan M. Ajmal
Published: October 2012

Soil salinity is a major impediment to crop production in many parts of the world. This necessitates search for suitable alternatives to meet the demands of burgeoning populations. Opening new lands for cultivation is not without dire ecological consequences while domestic, industrial, and agriculture utilization have increased pressure on good quality water resources. Hence, we have to live with the abundantly available saline arid lands and salty waters. In this background, logic demands that attention is to be paid to the vegetation of those habitats, which have been degraded by salinity and identify plant species growing there which may be suited to our needs. These wild plants (halophytes) could be cultivated and put to an array of usages like food, fodder, fuel wood, oilseed, medicines, chemicals, landscaping, ornamentals and environmental conservation through carbon sequestration. Halophytes have a history of being a valuable resource for utilizing saline lands and brackish water however their utilization has remained relatively unfulfilled. We have identified a number of species from the halophytic flora of the Sindh/Balochistan coast of Pakistan and adjoining inland areas that have potential for use as a feed crop for animals. Initial studies have shown that seeds of a number of halophytes can produce sufficient quantity of good quality edible oil having 70-80% unsaturated fatty acids. Ethno-botanical survey has established the presence of a number of halophytes with prospect of medicinal use for various ailments. Similarly, several species have been identified as source of biofuel/biodiesel. Species exist with potential to check shifting sand dunes and serve as a carbon sink. The above findings are of particular significance keeping in view the fact that both Pakistan and Qatar are largely arid with considerable overlapping of flora. Implication of our research conducted at University of Karachi on the sustainable development of Qatar would be discussed.
Lipophilic compounds in femoral gland secretions of spiny-tailed lizard, dhub, Uromastyx aegyptia microlepis (Reptilia, Agamidae) from the Qatar desert
Authors: Martín Jose , Castilla Aurora , Lopez Pilar , Al Jaidah Mohammed , Mohtar Raby
Published: October 2012

In many lizards, chemical compounds from the femoral gland secretions are used in intraspecific communication, but most studies describing these chemicals are for European lizard species included in the Scleroglossa clade. Lizards within the Iguanian clade have been much less studied, probably because these lizards were considered to rely more on visual cues. However, many iguanian lizards have abundant femoral secretions and are able to exercise chemosensory conspecific recognition, which might be based on compounds secreted by femoral glands. To understand what determines the composition of gland secretions of lizards and their role in social behavior, we need more studies that deal with a wider range of lizard species within different taxonomic groups and to consider a larger variety of environmental conditions. By using gas chromatography-mass spectrometry (GC-MS), we found 85 lipophilic compounds in femoral gland secretion of male and female spiny-tailed lizards, Uromastyx aegyptia microlepis. The type of compounds were similar between sexes, but males had a greater diversity of compounds (n= 80) than females (n= 64), and some specific compounds were exclusive of either males or females, and proportions differed between sexes. Main compounds were 27 steroids (58.6 % in males vs. 83.2 % in females; mainly cholesterol and 4,22-stigmastadiene-3-one), 13 carboxylic acids and some of their esters (16.5 % in males but only 1.5 % in females; mainly hexadecanoic acid), 4 terpenoids (mainly squalene; 9.5 % in males vs 3.6 % in females), 23 waxy esters of fatty acids (6.5 % in males and 6.1 % in females), α-tocopherol (3.4 % in males and 2.1 % in females), ketones (1.6 % in males and 2.0 % in females) and other minor compounds such as aldehydes (0.8 % only in males) and alcohols (0.5 % in males and 0.1 % in females). We compared these compounds with those found in other lizard species and discussed the potential signaling function of some compounds and how the xeric habitat could have conditioned the composition of secretions in order to maximize the efficiency and durability of scent marks in the desert.
Genetic divergence among populations of the darkling beetle Adesmia cancellata in Qatar
Authors: Mas-Peinado Paloma , Castilla Aurora , Garcia Paris Mario , Saifelnasr Essam , Mohtar Rabi
Published: October 2012

The darkling beetle Adesmia cancellata Solier, 1835 (Coleoptera: Tenebrionidae) is considered a dominant arthropod in the Qatari desert as suggested by previous studies. The species is also distributed in the Arabian Peninsula, Syria and Israel. The objective of our study is to explore the evolutionary history of this species in Qatar through genetic analysis.

We first collected different individuals of A. cancellata in the field from 12 populations distributed across Qatar between February and April 2012. We used partial sequences of the cytochrome oxidase mitochondrial marker (COI) to reveal patterns of genetic structure underlying the geographic distribution of A. cancellata in Qatar, and indirectly, to infer dispersal rates and recent and historical patterns of gene flow between populations.

Phylogenetic analyses of mitochondrial sequences of this preliminary study show maximum values of 2% sequence divergence between populations. In order to explain such a low within species genetic diversity we propose the hypothesis hat the current genetic lineage of A. cancellata inhabiting Qatar entered the country quite recently, probably during the late Pleistocene. Since the time of Qatar colonization the species has spread across the country and became a dominant arthropod with respect population density and distribution area.

In order to test this hypothesis it would be necessary to extend our analyses to a larger number of populations in Qatar and to compare them with populations outside Qatar throughout the world distribution range of the species.
Studying and comparing the erosion-enhanced pitting corrosion of X52 and X100 steels
Authors: rauf abdul , Mahdi Sadig
Published: October 2012

The critical ratio of Cl to HCO concerning the corrosion rate has been determined with and without electrolyte erosion in 0.3 M NaHCO3 by using various concentrations of NaCl for X52 and X100 steels. The open circuit potential (OPC) was recorded for both steels in electrolytes containing 0.3 M NaHCO3 and 0.1 M NaCl without erosion, with electrolyte erosion, and with electrolyte-silica sand erosion. Electrochemical techniques such as linear polarization resistance (LPR) and potentiodynamic polarization scans were used to study and compare the material resistance against synergistic impact of erosion and corrosion. Scanning electron microscopy (SEM) and optical microscopy were used to study the morphology of pitting corrosion in the absence and presence of erosion. The change in pitting potential due to electrolyte and electrolyte-silica sand impingement has been discussed. The microstructure and hardness of X52 and X100 steels were evaluated and discussed with respect to the erosion-corrosion behaviors. Cracks were observed at the inner wall of a pit due to silica sand impingement during erosion-enhanced pitting corrosion. X100 steel is more stable than X52 steel against pitting corrosion with and without erosion. X52 steel suffered pitting corrosion in the standstill electrolyte containing chloride whereas X100 did not, even in the presence of erosion. Pits propagate in the direction of erosion because of the impingement and disruption of the passive layer in that direction.
Solar cogeneration power desalting plant with assisted fuel
Authors: Darwish Mohamed Ali , Mohammed Sayeed
Published: October 2012

Solar power plants using parabolic trough solar collectors, operating Rankine steam cycles, are well proven and the most widely used type of solar power plant (SPP) worldwide. These plants have a low power cycle efficiency (30%) due to low throttling conditions of 350-375°C and 100 bar. Conventional steam power plants have high throttling conditions (535-560°C and 140-160 bar) and high efficiency (38-40%).

An SPP was suggested for generating electric power and desalted seawater; i.e. a cogeneration power desalting plant (CPDP) in Qatar. Qatar has large natural gas (NG) resources and Qatar's power plants use NG-fueled gas turbines. However, NG resources are finite and NG consumption is rising. As in many countries, SPPs contribute to electric power and desalted seawater production. This prolongs the life of the NG resources, and maintains an export revenue stream. This also limits the emission of greenhouse gases and air polluting gases due to NG combustion, which badly affect the environment.
While NG is used in SPP to compensate the intermittent nature of solar energy, and keeps the operation during non-sunshine hours, its main purpose is to raise the SPP throttling temperature, and thus increases the steam cycle efficiency, even during full sunshine. It also lowers the cost of using expensive land where the SPP is planned. This paper studies the feasibility of utilizing NG to superheat the steam leaving the SPP solar collector field, and to heat the feed water to the collector. This drastically increases both power output and efficiency. Modifications of SPP power cycle to become a CPDP are presented.
Turbulent heat transfer measurements of supercritical CO₂ in a horizontal tube at relatively low Reynolds numbers
Authors: Tanimizu Katsuyoshi , Al-Suwaidi Shaikha , Sadr Reza
Published: October 2012

Supercritical fluids have captured global attention due to their extraordinary properties, such as high heat transfer coefficients, solubility and heat storage capacity. Due to the requirement for more effective power generation systems, supercritical Brayton cycles were proposed because of its high potential for the development of high thermal efficiency power cycles with no need for condensers. It is known that small fluid temperature and pressure variations near critical point or pseudocritical regions, result in significant changes to the thermo-physical properties of the fluid. However, the available correlations for convection heat transfer do not show sufficient agreement with the available experimental data to simplify industrial design except in very limited conditions. Therefore, further experimental investigations are still required to better understand the thermal and hydraulic behaviors of the supercritical fluids before they can be widely used in industrial applications.

In the newly developed test facility in Texas A&M University at Qatar, forced convection heat transfer of supercritical CO₂ in a circular horizontal tube at relatively low Reynolds numbers (Re <105) is investigated experimentally in a straight tube with an inner diameter of 8.7 mm. Experiments are carried out for different mass flow rates, fluid inlet temperatures, system pressures, and semi-local heat transfer coefficients, which are recorded at several locations in the pipe with constant heat flux. The influence of the fluid bulk temperature and pressure on the forced convection heat transfer in the tube was then recorded and compared to widely used empirical correlations. The results indicate that the effect of buoyancy on the heat transfer coefficient cannot be ignored in the near critical or pseudocritical region of fluids for this flow geometry. This dependency is believed to be due to extreme dependence of fluid properties on temperature in this region. The results suggest that the heat transfer correlation should include the buoyancy effects especially near the pseudocritical region. Therefore, new empirical correlations in horizontal pipes is proposed based on our experimental results of the heat transfer measurements. An effort is undertaken to design an inclined pipe test section for the existing facility to further study the effect of buoyancy of this flow.
Protecting the Arabian oryx by genome sequencing
Authors: Al-Dous Eman , Al-Malki Ameena , Al-Azwani Eman , George Binu , Salameh Yasmeen , Bouts Tim , Sayed Atef , Shykind Benjamin , Mohamoud Yasmin , Malek Joel
Published: October 2012

Background and Objective:
The Arabian oryx (Oryx leucoryx) was hunted to near extinction in from the 1950s to the 1970s. Thus, the oryx ranks among the rarest mammals in the world. Qatar currently has ~800 oryx and has donated numerous oryx to breeding programs around the world. As such, Qatar may be a significant source of genetic diversity to the worldwide oryx population.
The primary purpose of this project was to provide a genome sequence and Single Nucleotide Polymorphism (SNP) data in hopes it can be used for improving breading strategies by maintaining as much genetic diversity as possible.

Methods:
A DNA sample was provided from an oryx male in the Wabra Wildlife Preservation in Qatar.
The animal's whole genome was sequenced using next-generation sequencing approach. After assembling the contigs, we utilized a 67bp kmer and ~2.4B paired 100bp (~80X coverage) reads from the Illumina HiSeq. These reads were distributed across libraries ranging in size from 300-1200bp for paired-end and 2000-5000bp for mate-pair libraries. Genome physical coverage by mate-pair libraries was approximately 15X. De novo gene prediction was conducted on scaffolds >500bp. SNPs were also detected. Results: Predicted genome size of ~3Gb (similar to other Mammals), a scaffold N50 of ~300kb, an assembly spanning ~2.5Gb of the genome which is likely >90% of euchromatic sequence. The sequence is distributed across 36,964 scaffolds greater than 500bp. We detected ~1M SNPs between parental alleles, which is significantly fewer than in other "rare" animals such as the giant panda.

Conclusion:
The initial analysis of polymorphisms suggests a relatively high level of inbreeding, and further study will be needed to clarify whether this is only in certain herds or a worldwide issue.
The antimicrobial properties of Arab desert plants
Authors: Strickland Jennifer , Madzia Susan
Published: October 2012

Background and Objectives:
Due to overuse and inappropriate use of antibiotics, many pathogens are now highly resistant to common antibiotics. This has caused difficulties in controlling disease, particularly in developing countries, where infectious, enteric and diarrheal diseases are a leading cause of illness and mortality. The purpose of this study was to determine the antimicrobial activity of Qatar's local desert plants in an effort to find potential new sources of antimicrobial agents that may be effective in the fight against existing and emerging infections.

Methods:
Nineteen desert plants were collected in the winter of 2011. Their parts were separated into flower, leaf, stem and root, and, in one plant, seeds. Each plant part was extracted with water, hexane and methane. The plant extracts were tested for their antimicrobial activity against 10 Gram-positive and Gram-negative common human pathogenic bacteria as well as a fungus--Candida albicans. The Kirby-Bauer disk diffusion method was used for testing, and the resulting zone of inhibition, which indicates antimicrobial activity, was measured and recorded.

Results:
All nineteen plants included in this study demonstrated some antimicrobial activity in one of the four plant parts. Paronychia argyrocoma showed the strongest activity, inhibiting growth in both Gram-negative and Gram-positive microorganisms in all extracts. Salvia aegyptiaca, Pulicaria undulata, Althea ludwigii, and Vicoa pentanema also exhibited positive results in all extracts in many of the plant sections.

Conclusions:
This study indicates that many of the desert plants tested are an important source of antimicrobial compounds. Several plants showed remarkable antimicrobial effects against a wide variety of Gram-positive and Gram-negative pathogens. This study supports the use of these local plants in traditional medicine and may provide sustainable and new sources of antimicrobial agents. Further studies are needed on the most active plants to explore the development of new antimicrobial drugs.
Smart metering project: Benefits and lessons
Authors: HAOUCHE Mohamed , MANSON Simon , DEFFOUS Younes , AUTHIER Jean-Francois
Published: October 2012

Total E&P Qatar (TEPQ) have made a significant effort to test new approaches to improve its current production metering systems for multiphase flow conditions. New technologies are tested through pilot applications on field. One of which is the use of advanced data validation and reconciliation (DVR) in oil and gas production activities. The goal is to reconcile in real-time the measured data and estimate all new information from a plant, which are not continuously measured. In this case, the target is the three phase flow rates: oil, water and gas.

The study intends to provide a summary of the achievements, benefits and lessons learned from the application of DVR pilot on multiphase flow metering in Total's field in Qatar. This field is operated by Total under a production sharing agreement with Qatar Petroleum.

Theoretically, the DVR approach uses information redundancy to correct data and re-evaluate its accuracy. Direct measurements and model parameters are processed at the same time. The input data consists of pressure volume temperature measurements (fluid) and electrical power consumption (motor current, voltage & frequency). We have derived models to estimate the flow rates of the three phases on the basis of these input data. Simultaneously, thanks to the reconciliation process, the input data are corrected with respect to material and energy balances. The output results constitute a set of reconciled data and calculated information with high accuracy.

The DVR pilot is currently in the process of finalization to become an operational tool. Online acquisition and processing is performed and daily reporting is shared among operational engineering teams. It was found that the major challenge was related to the modelling of production equipments. A significantly longer period of time was allocated to better understand their actual behaviour in real environments.

In conclusion, this pilot study of new approaches has allowed us to enhance the reliability of our metering system and increase our efficiency for installation assessments. Moreover, these findings will allow researchers to conduct further studies with more operational challenges. Further conclusions will be presented in this paper.
Biodegradation polycyclic aromatic hydrocarbons (PAHs) in the soil of Arabian Gulf region of Saudi Arabia
Authors: Elshinawi Kawther Elsayed Fahmi , Mourad shaza
Published: October 2012

The environmental fate of the polycyclic aromatic hydrocarbons (PAHs) is prompted by their ubiquitous distribution and their potentially deleterious effect on human health by their carcinogenic and mutagenic effects. PAHs are the most important components retained in the soil environment after an oil spill. Biodegradation of PAHs by microorganisms is the subject of many reviews, but every habitat had its own personality. Our study was selected by satellite images for Marduma Bay, located in the north-west of Jubal industry city, which lies on the coast of the Arabian Gulf of Saudi Arabia and is described as a heavy polluted region. Its polluted rate was identified between (8 to 10% w/w.) Chenopodium sp. is a naturally dominant plant that tolerates both salinity and pollution. Three soil samples were collected. The first one is the rhizosphere sample (R 4) in addition to two soil samples; one of polluted area (S5) & non-polluted one (S0).
The rhizosphere sample showed the maximum bacterial count for both total heterotrophic bacteria, which was (98.2 to 94.2+0.1 CFUx106/g); and maximum count for oil degrading bacteria, which was (55.3 to 45.1+0.01 CFUx106/g). The concentrations of oil-degraders in different habitats were recorded on mineral media supplement with 2% crude oil as the only carbon source, thus recording a positive effect of the rhizosphere and phytoremediation process. As for the results of oil degrading microorganisms, soil samples of polluted regions (S5) and non- polluted soil (S0) indicated concentrations of (93.5 to 82.2+0,01 CFUx104/g) and (11.9 to 12.2+0.02 CFUx 104/g) respectively, and thus recording adaptation of this group of organisms in polluted habitat. The biodegradation of 16 PAHs individuals in both the rhizosphere (R4) sample of Chenopodiaceae and non-rhizosphere (S5) sample during 180 days was (77.4%) for the rhizosphere and (52.2%) for the non-rhizosphere. The residual of total carcinogenic PAHs with four rings structures recorded a loss between (55.7 to 75.4%) and (24.3 to 46.1%) for the five rig structure. Also, the residual of total carcinogenic PAHs was (49.1%) for the rhizoshpere and (31.7%) for the non-rhizosphere.
Assessing the impact of atmospheric aerosols and clouds on solar power generation systems in Qatar and the Middle East
Authors: Khan Maudood , Ayoub Mohammed , Mohieldeen Yasir Elginaid , Biazar Arastoo , Newchurch Michael
Published: October 2012

Background & Objectives:
Renewable energy generation systems are highly sensitive to climate. For example, clouds have a significant influence on solar power generation systems. They in turn are impacted by atmospheric aerosols which act as cloud condensation nuclei. Aerosols are both directly emitted from anthropogenic (e.g., power plants, transportation systems, industrial facilities) and natural sources (e.g., windblown dust, sea salt, forest fires), and form in the atmosphere. They can either inhibit or promote cloud formation, and/or precipitation, and thus are likely to play a significant role in altering the hydrological cycle, and perhaps electricity generation from hydroelectric, solar, and wind power systems. Integration of renewable energy systems within existing power generation infrastructure systems remains a challenging task as well. The objective of this study is to use cutting-edge satellite imaging technology and observations and coupled models to identify atmospheric variables and processes that impact solar power generation systems in Qatar and the Middle East.

Methods:
We will employ data from the Aerosol Robotic Network (AERONET) in situ measurements, Moderate Resolution Imaging Spectroradiometer (MODIS) satellite, and the Clouds and the Earth's Radiant Energy System (CERES) scanner. We will also assess the potential impact of future changes in atmospheric composition, clouds, and radiation on solar power generation systems. For this purpose, we will employ version 5.0 of the Community Multiscale Air Quality (CMAQ) modeling system, and the Weather Research and Forecasting (WRF) model.

Results:
The research will provide a set of model and satellite-based maps showing the spatial and temporal distribution of aerosols over the region, potentially assisting analysis aimed at identifying sites for solar power generation systems in Qatar.

Conclusions:
The research project will help establish the knowledge infrastructure that relies on computational science and space technology to ensure that Qatar continues on the path of economic prosperity through effective integration of emerging technologies with existing infrastructure.
Development and characterization of high strength steel for down hole application in sour environments with superior corrosion and wear resistance
Authors: Khalfaoui Walid , Palmer Bruce , Michra Brajendra
Published: October 2012

Background and Objectives:
The down hole application environment is highly corrosive due to the presence of hydrogen sulfide and carbon dioxide in brines. To handle this environment, special materials with a high resistance to pitting corrosion and a high capability of repassivation are used such as steels containing molybdenum, chromium and nickel. The cost of the metallic constituents in these alloys can preclude their use in some applications. The objective of this study is to provide cheaper materials withstanding these conditions. The materials developed in this study are high interstitial stainless steels (HISS) with high nitrogen and carbon content.

Methods:
Several studies showed that the addition of nitrogen and carbon in stainless steels enhance their pitting corrosion resistance, increase their critical pitting temperature and also increase their repassivation rates. In order to develop high nitrogen and carbon content stainless steels we employed the air-casting techniques developed by the Colorado School Mines. In these techniques, the nitrogen is added to the melt using nitrogen-bearing additives (nitrided manganese). In this case, the nitrided manganese is placed in cavities in the mold, and melts when the liquid metal enters the mold. In order to characterize the chemical and mechanical properties of the HISS several tests were performed. The XRF and the EDX techniques were used to determine the chemical composition. The microstructure was observed using an inverted optical microscope and a scanning electron microscope. The corrosion resistance to 3.5% sodium chloride solution was studied using weight loss and electrochemical tests. The corrosion tests under sour environment will be performed as soon as the sour gas research laboratory will be constructed. The hardness of the HISS was measured using the Rockwell hardness test.

Results:
Preliminary investigations show that the microstructure of the developed materials contain nitrites and carbides which have a bad effect on the pitting corrosion. This problem can be solved by applying the adequate heat treatments. These results also show that the developed stainless steels are harder than nickel-molybdenum.
A study on the bacterial infertility and hormonal imbalance in camel (Camelus dromedarius) with the effect of extreme heat of environmental temperature during summer of 2012 in Qatar
Authors: Cruz Luningning Mariano
Published: October 2012

A comparative study will be conducted on the presence of bacterial infection and hormonal imbalance in camel (Camelus dromedarius), which precipitates to infertility incongruent with extreme summer heat under field conditions. Parameters are as follows; confinement, feeds consumed, uterine swab, detectable heat cycle, and weight and age of 50 female animal samples. The trial period timetable is 90 days between May and August. Data collected is summarized with blinding and randomization trial design. Maintenance of trial treatment randomization codes and procedures were kept in the electronic record data.
Dynamic stress state around a nanosized spherical reinforcement due to a scattering of elastic shear waves
Authors: Bugarin Sinisa
Published: October 2012

Background and Objectives
Nanostructured devices are finding ever increasing use in industrial applications which has prompted a need to further understand their mechanical properties. Research has shown that as the size of structures such as reinforcing particles and fibres is reduced to nanometers, their particular mechanical properties vary. This variation of the material behaviour has mainly been attributed to surface/interface energy around the free surface or interface of the nanostructures. Since such nanostructured materials exhibit characteristic length in nanometers, their elastic properties are affected by surface stresses that can displace atoms from the equilibrium positions which they normally occupy in bulk macroscopic assemblies. As such properties are not normally noticed in macroscale, as they are limited to only a few atomic layers, the free surface/interface effects are often neglected in the classical continuum mechanics. This paper investigates the effect of the surface/interface elasticity on the dynamic stress state in a matrix around the nano-particle reinforcements due to asymmetric dynamic loading.

Methods
In the surface/interface elasticity theory, an interface between a nano-particle reinforcement and matrix is considered a negligibly thin surface or a membrane glued to the underlying bulk materials without slipping. The elastic constants of the membrane are different from those of its adjoining materials, and its inertia can be neglected in the dynamic problem. This leads to a set of non-classical boundary conditions at the interface.

Results:
Different surface properties are investigated under varying frequencies of shear waves as well as different matrix and nano-reinforcement material properties. The stress concentrations values around the nano-particles are found to be significantly dependent on the frequency of excitation and surface properties. The effect is localized near the nano-particle matrix interface and disappears away from the interface into the matrix bulk.

Conclusions:
Dynamic stress field at the reinforcement-matrix interface is significantly affected by surface/interface elasticity as the reinforcing particle size reduces to nanometers. The increasing surface elastic constant μs can significantly reduce the stress concentration values at the nano-particle matrix interface.
Exceptional CO2 absorption by covalent organic polymers (COPs)
Authors: Yavuz Cafer Tayyar , Patel Hasmukh , Karadas Ferdi , Deniz Erhan , Atilhan Mert
Published: October 2012

Efficient CO2 scrubbing without a significant energy penalty remains an outstanding challenge for fossil fuel-burning industries where aqueous amine solutions are still widely used. Porous materials have long been evaluated for next-generation CO2 adsorbents. Porous polymers, robust and inexpensive, show promise as feasible materials for the capture of CO2 from warm exhaust fumes. We report the syntheses of porous covalent organic polymers (COPs) with CO2 adsorption capacities of up to 5616 mg/g (a world record-measured at high pressures, i.e., 200 bar) and industrially relevant temperatures (as warm as 65 C). COPs are stable in boiling water for at least one week, and near infinite CO2/H2 selectivity is observed. Theoretical calculations refer to an amorphous extended framework as density is likely the main reason for exceptional CO2 capacities. COPs 1-2 feature basic nitrogen sites that show chemospecific affinity towards acidic gases such as CO2. COP-3 has reasonably high surface area (418 m2/g), effective for low pressure operations. Post-combustion carbon capture from fossil fuel power plants demands pressures of up to 6 bar and a minimum temperature of 40 C. By tuning their architecture, we show that COPs reach to 3 mmol CO2/g sorbent at 6 bar and 45 C. High and low pressure capacities make these porous polymer structures viable alternatives to amine scrubbers*.

*H. A. Patel, F. Karadas, A. Canlier, J. Park, E. Deniz, Y. Jung, M. Atilhan*, C. T. Yavuz*, J. Mater. Chem., 22, 8431-8437, (2012).
Nanotechnology methodologies play a unique role in energy production and biomedical applications
Authors: Al-Ani Maan Nassar , Richrdson Martin , Jabor Al-Thani Khalid
Published: October 2012

Background and Objective:
Today, nanotechnology is being used by many industries and universities to develop new, safe manufacturing procedures for nanostructures, polymeric nanocomposites, polymer photonic components and devices, and other revolutionary biomedical devices and systems with nanoscale functions. Nanotechnological innovations are the key to the safe application of these procedures in science and engineering. Our goal in this study is to minimize the human health risks associated with emergent products and the replacement of existing, harmful products with non-toxic nanomaterials and non-destructive nanodevices.

Methods:
We propose the use nanofabrication techniques, along with production of new nanomaterials, as a potential avenue to enhance the two fastest growing fields of science and industry, biomedical research and renewable energy. An example of nano- applications in connection with these two very different scientific fields is the use of photon production techniques. We use photon production techniques to harvest energy capable of enhancing solar energy grids, enhancing nanochemical material's ability to absorb heat in nuclear reactors, and to stimulate nanorobotic labeled nanoparticles to kill cancer cells. These photons are produced from two mean light sources--the sun's rays (UV) and lasers.

Result:
In this study, our data clearly shows the effect of photons on labeled nanomaterials on the surface of nanorobotic devices and shows the ability of these devices to locate and differentiate cancer cells from healthy cells. Parallel to these studies, we are still in the process of collecting data in relation to photons' effect on nanomaterials and their ability to manipulate nanoparticles, allowing for safe energy production in nuclear power reactors. These same photons also have the ability to augment nanomaterials on solar grids, enhancing solar energy production.

Conclusion:
Data analysis shows that advances in nanotechnology methodologies will play a critical role in achieving greater environmental gains in renewable energy, including safer, more efficient nuclear energy production. Methods of photon applications on nanostructures in biomedical research can be adapted to similar interactions between photons and nanoparticles, leading to the evolution of current energy production processes.
Inter- and intra-specific genetic variations among Qatari date palm cultivars using inter simple sequence repeat (ISSR) markers
Authors: Ahmed Talaat , Al-Hadidi Sarah , Al-Qaradawi Asmaa
Published: October 2012

Date palms are generally propagated by separating the offshoots produced by individual trees. This method maintains the genetic integrity of date palm cultivars. Individual trees of well-known Date palm cultivars have little differences in fruit morphological characters and quality especially color and sweetness. The objectives of the present study are to analyze the genetic diversity among most common cultivars of Qatari date palm as well as the genetic variation within each cultivar. Five common Date palm cultivars in Qatar were selected including Khalas, Sheshy, Rezezy, Barhee and Khanezy from three different locations (Al-Shamal, Al-Khour and Al-Rayan). This study tried to answer basic questions about the genetic similarity or diversity among and within the well-known Qatari date palm cultivars using 18 Inter Simple Sequence Repeat (ISSR) primers. All primers have amplified polymorphic bands in the studied cultivars either among the cultivars or within each cultivar in different cultivated areas. The results indicated the existing of genetic variations among well-known cultivars as well as within each cultivar explaining the variation in some morphological and quality characters for different trees of the same cultivar that are grown in different environments.
Threat resistant sandwich walled structural system
Authors: Ebrahimi Hamid , Hamouda Abdel Magid , Vaziri Ashkan
Published: October 2012

Background:
Sandwich panels with low density core constructions are a class of structural elements with superior structural performance compared to traditional solid panels. Sandwich panels, compared to solid panels of equal mass, generally have much higher bending stiffness and comparable stretching stiffness, thus undergoing smaller deformation under loading. The potential advantage of sandwich panels for mitigating shock and projectile loading has been established in literature. The previous studies related to understanding the mechanics and structural performance of sandwich structures are mainly focused on studying the behavior of the core construction or the performance of a single isolated sandwich panel. These studies have provided significant insight into the behavior of sandwich panels, which includes mechanisms of energy dissipation in the core, stages of deformation of sandwich panels as they get impinged by an intense shock, fluid-structure effects for shock waves transmitted in air and water, and the mechanism of deformation and failure of sandwich panels under shock and projectile loading.

Objective:
This study extends previous research by exploring the behavior and structural performance of structural systems made of sandwich walled panels. The objective is to explore the potential benefit of sandwich configurations in enhancing the overall behavior of structural systems under complex loading conditions that could occur in petrochemical industry settings and pipeline networks.

Method:
We considered three frame structures, (i) frames made of solid panels (ii) frames with sandwich panel side walls and (iii) frames where all walls are made of sandwich panels. We also considered sandwich walled cylinders resembling pipes and compared their performance with the mechanical behavior of traditional pipes made of solid metal hollow cylinders. We used detailed finite element models to simulate the response of these structural systems.

Results:
The results showed that sandwich walled frame and cylinder (pipeline) configurations, in general, undergo smaller deflection than traditional counterpart structures under both quasi-static and high intensity dynamic (shock) loadings.

Conclusions:
The results highlight the potential of sandwich walled structural systems for developing novel threat resistant structures especially for the petrochemical industry and pipeline networks.
Properties of 2:1 aqueous strong electrolytes using the Q-electrolattice equation of state
Authors: Checoni Ricardo Figueiredo , Zuber Andre , Castier Marcelo
Published: October 2012

Electrolyte solutions occur in many natural systems and are present in several industrial processes. Aqueous solutions of electrolytes are particularly important for designing water purification and treatment systems, among which water desalination processes. The design of processes with electrolyte solutions may require determining phase equilibrium conditions, and predicting volumetric and calorimetric properties. Equations of state (EOSs) are, in principle, capable of such predictions and, for this reason, a several equations of state (EOS) have been developed considering the ionic interactions in electrolytes solutions. An example is the electrolattice equation of state. This model evaluates the Helmholtz energy as the summation of three contributions: the first considers the short range interactions (by using the Mattedi-Tavares-Castier equation of state (MTC-EOS)); the second, the Born contribution term, accounts the solvation effects; the third, the primitive mean spherical approximation (MSA) term, describes the long range effects. In the electrolattice EOS, the diameters of cations and anions are considered to be equal. In this work, we calculate vapor pressures, mean ionic activity coefficients, osmotic coefficients, and densities of mixtures containing water and a single 2:1 strong electrolyte with a revised version of the electrolattice EOS, which is called Q-electrolattice EOS. The latter preserves the first and the second contributions of the electrolattice EOS, but includes another MSA term, which is an explicit mean spherical approximation under the assumption the ions have unlike diameters. The water molecule is assumed to have a dispersion region, an electron-donor region, and an electron-acceptor region. To reduce the number of adjustable parameters of the model, the ionic diameters are taken from the literature. Also, interactions between the each ion and each of the three regions of the water molecule are assumed to be equal. Finally, short range interactions between ions are neglected. With this set of assumptions, the inclusion of each ion only requires the fitting of one additional parameter. The work compares the performance of the electrolattice and Q-electrolattice models with respect to other equations of state for similar applications.
Criticality measures for components with multi-dimensional degradation
Authors: Xiao Liu , Al-Khalifa Khalifa , Magid Abdel , Coit David , Elsayed Elsayed
Published: October 2012

Background:
Many failures of engineering structures and equipment are attributed to the failure of a single component. It is of great importance to identify those critical components and understand how components' criticality changes over time under dynamic environments.

Objective: In this paper, we investigate the criticality analysis for components with multi-dimensional degradation under time-varying environmental conditions.

Methods:
The component degradation is modeled as a k-dimensional Wiener process and a component fails when any of the k degradation processes attains a threshold level. Results: Since the degradation process is often influenced by the environmental conditions, we assume that both the mean and diffusion of the degradation process are time-dependent functions for a given environmental profile, which evolves either deterministically or stochastically.

Conclusions:
We derive expression for the criticality measure of the component with time, illustrate the analysis of component criticality under time-varying environmental conditions and demonstrate the necessity to consider the change of environmental conditions in analyzing component criticality.
A novel multiphase multilevel inverter topology for high power AC drives with open-end stator windings
Authors: Rajeevan P.P. , Abu-Rub Haitham , Iqbal Atif
Published: October 2012

Realization of multilevel inverters for multiphase high power AC drives with open-end windings is presented in this paper, with a specific case of five-phase five-level inverter configurations. The five-level voltage profile is realized by feeding both ends of the stator windings using a three-level five-phase flying capacitor inverter on one side and a five-phase two-level inverter on the other side. The flying capacitors' voltages are effectively balanced by utilizing the switching state redundancies. The capacitor voltages can be balanced at any modulation index, irrespective of the operating power factor. The operation of a drive at a higher voltage is preferred in many applications due to the advantages such as higher efficiency and reduction in size and weight. However, this demands higher DC link voltage in many topologies. The DC voltage magnitude required in the proposed topology is half of that required in the conventional multilevel neutral point clamped (NPC) topology, for a given output voltage. Hence, the scheme proposed in this paper can be advantageous in such applications where there is a limitation in obtaining DC voltage sources of higher magnitudes, such as in electric and hybrid electric vehicles. Another attractive feature of this topology is the enhanced reliability, as it is possible to operate the drive with half power even if any one of the inverters completely fails. The number of active switches used in this topology is lesser than that in equivalent five-level NPC inverters. Unlike the NPC inverter, this topology does not require any clamping diodes and is also free from issues like neutral point fluctuations. A carrier based pulse width modulation (PWM) technique combined with a hysteresis controller for balancing of the capacitors' voltages is used for the control of the inverter. The proposed drive topology can be applied to high power AC drives such as in oil and gas industries, electric/hybrid electric vehicles, ship propulsion, traction etc. The simulation and experimental results support the proposed idea.
Water contamination: Cadmium in drinking water
Authors: Aboujassoum Hamda Mohammed , Costa Ozeas S.
Published: October 2012

Cadmium is a naturally occurring metal and is usually present in the environment as a mineral combined with other elements, such as oxygen, chlorine, and sulfur, or as a minor component of most metal ores such as zinc, lead, and copper. Cadmium is also released in the environment from industrial activity; in particular, ore-smelting plants, industrial paints, and agricultural fertilizers. Over the last few decades, considerable attention has been paid to the evaluation and detection of cadmium contamination in the environment, mostly because of the relationship between cadmium exposure and the development of chronic health problems, including renal dysfunction, osteoporosis, and carcinogenesis, as well as developmental and reproductive problems. Water contamination by cadmium is of particular interest because of its high solubility in acidic conditions. Contamination of drinking-water may occur as a result of the presence of cadmium as an impurity in the zinc of galvanized pipes or cadmium-containing solders in fittings, water heaters, water coolers and taps. The aim of this study is to evaluate the availability of cadmium in drinking water in Qatar. Five samples of municipal water were collected from different locations in Doha--Al-Wakra, Dafna, Salwa Road, Al-Kharitiyat and Sailiya--to examine the availability of cadmium in drinking water. Analysis was performed by injecting the samples directly into an ICP-OES machine and obtaining the results. The results showed that the cadmium concentration in all samples was below detection (detection limit for Cd: 0.7 ppb). These low Cd concentrations in drinking water in Doha may be related to the fact that both dissolved and particulate matter are being removed from seawater during the desalination process. In addition, the absence of these toxic elements may be related to the water distribution system being relatively recent and containing cadmium-free pipes.