Qatar Foundation Annual Research Conference Proceedings Volume 2014 Issue 1

Background Marine phytoplankton form the basis of the marine food chain and are essential for the normal functioning of ecosystems. Any disturbance to this component, due to the release and accumulation of toxic compounds can have an impact on higher trophic levels. In this study, we investigate the impact of toxicants on the microalgae isolated from Qatari seawater and cultured under controlled laboratory conditions. Objectives * Develop a toxicity test for Synechococcus sp that can be added to the suite of tests currently available for marine invertebrates and fish. * Perform chronic toxicity tests of three reference toxicants (DCA, SDS and Zn) * Evaluate the sensitivity of Synechococcus sp to three reference toxicants and compare sensitivity to other species used in toxicity tests. Methodology Chronic toxicity tests were carried out in 24-well microplate for a period of 3 days for the DCA and Zn tests and 7 days for SDS test. Algal cultures in logarithmic growth phase (cell density of about 3.105 cells mL−1) were used as inoculum. Each test consisted of at least five test concentrations and a control, in triplicate. A different range of concentrations were used to estimate the range findings for each toxicant. * Cell counting using an hemocytometer was conducted to evaluate the inhibition of microalgal growth * The average specific growth rate and the percent inhibition of growth rate were calculated, the lowest observed effect concentration (LOEC) and the no observed effect concentration (NOEC) were statistically determined. Results A growth inhibition toxicity test was successfully developed for Synechococcus sp, which was isolated from Qatari coastal waters. Prior to conducting the toxicity testing, key environmental parameters including light, temperature and nutrients were optimized to obtain acceptable algal growth rates over 72 hours. Results showed that Synechococcus sp was more sensitive to DCA than SDS and Zn. The growth of Synechococcus sp was found to be stimulated by the SDS at the beginning of the test. The growth inhibition by the SDS on Synechococcus sp was shown by day 3 of the experiment. At a longer exposure time, significant values of the percent inhibition of growth rate were reached compared to the control. Conclusion and Discussion Controlled experiments on microalgae under laboratory conditions provide an opportunity to understand the action of these toxicants in the ecosystem. The growth stimulation in the Synechococcus sp test sample seems to be related to the ability of the microalgae to use the SDS as a source of carbon. Inhibition of cell growth under the influence of high concentrations of SDS may result from the destruction of cellular structures and disruptions of metabolism. The findings in this study showed that Synechococcus sp possess a number of desirable characteristics for use in toxicity assessment. In particular, the algae's high sensitivity to environmentally relevant toxicants makes it a suitable choice for site-specific testing. Therefore, we recommend that they be considered, along with other local organisms, as part toxicity tests in the region.

Objectives: The purpose of this study is to sequence and annotate the genomes of the entire spix's macaw population "the world's most endangered parrot" at AWWP (of Al Wabara Wildlife Preservation). This data would be used to identify Single Nucleotide Polymorphism (SNPs) that would later be used in population studies of this species. The results would be used to guide future breeding programs to increase the genetic diversity of the spix's macaw, which will lead to the ultimate objective of the reestablishment of a self-sustaining population of Spix's Macaws in its native Caatinga habitat. Methods: DNA samples, thus far, were provided from 40 males and females at the AWWP. The spix's macaw whole genome was sequenced using Next-Generation sequencing approach. For the genome assembly, we utilized a 63bp kmer and ~1.1 billion paired 100bp reads (~66x coverage) from Illumina HiSeq 2500 instruments. These reads were distributed across libraries ranging in size from 300-1000bp for paired-end and 2000-15000bp for matepair. SNPs were detected on scaffolds >1000bp. Results: The predicted genome size is ~1.5Gb, which is similar to the parrot genome, the closest sequenced species. Scaffold N50 of 3.1Mb (longest scaffold of ~16.5Mb) and an assembly spanning >92% of the genome. The sequence is distributed across ~6500 scaffolds >500bp. Heterozygous SNPs with coverage of >20x were considered to analyze the survival rates of offspring. We noticed that the average percentage of unique heterozygous SNPs in a bird drastically dropped to below 50% when compared to a second bird. This percentage further dipped exponentially each time another bird was added to the comparison. The average percentage of unique heterozygous SNPs fell to below 10% when 8 birds were compared for unique heterozygous SNPs. This shows that random mating combinations increase the chance of generating offspring with decreased survival rates due to loss of heterozygosity. Conclusion: The initial analysis of polymorphisms confirms the existence of a very high level of inbreeding, in which a random recombination of birds could result in offspring with very high levels of homozygous SNPs by the 4th generation. Further study will be needed to identify detrimental SNP combinations. This information will be used to better understand the genetic pool and to promote better breeding results with higher offspring survival rates.

In this study sandwich-walled cylindrical shells with aluminum pyramidal truss core of constant curvature suitable for functional applications were fabricated employing an interlocking fabrication technique for the metallic core. The skins were made of carbon-fiber reinforced composites and co-cured with the metallic truss core. Thereafter, axial compression tests on some representative samples were carried out to investigate the failure modes of these structures and compared with an analytical failure map developed to account for Euler buckling, shell buckling, local buckling between reinforcements and face-crushing. The experimental data closely matched the analytically predicted behavior of the cylinders. In particular, it was found that local buckling and face crushing modes can exist together and are the most important modes of failure of the fabricated structure. In addition, a study on the bending response of semi-cylindrical samples is also presented using a combination of analytical modeling, three-point bending experiments and finite element (FE) based simulations. The aluminum pyramidal cores of these samples were also constructed using the novel interlocking method before curing them with composite face sheets to fabricate the final structure. A theoretical model was developed to analyze the experiments and develop failure criteria. Three failure modes: i) Face wrinkling, ii) Face crushing, and iii) Debonding between face sheet and truss cores, were considered and theoretical relationships for predicting the collapse load associated with each mode were developed. The experiments were carried out on two sets of specimens with differing face sheet thickness which clearly indicated the important role played by core debonding in determining the peak load of the structure. Localized buckling instabilities were also reported for samples with thinner face sheets. The role of debonding in determining strength was further highlighted by a comparison with FE simulations with suppressed debonding. This study highlighted the superior structural performance and failure properties of these structures thus demonstrating their suitability for their integration into the next generation of ultralight multifunctional systems.

Oxide semiconductors have been widely used in the area of sensors, energy conversion, and environmental cleanup technologies; because of their high multifunctional photo-activities. However, the overall performance of oxide semiconductors is influenced by their photocatalytic activities which are highly dependent on physical properties such as crystallinity, surface area, morphology (e.g., shape and porosity), etc. Thus, understanding the shape-dependent photocatalytic reactions is important for energy or environmental cleanup applications. Herein, two different types of ZnO, rods and plates, were synthesized using solvothermal technique and the shape-dependent photo-activities were evaluated for degradation of methylene blue and phenol and for hydrogen evolution. Experimental results showed that the surface area and bandgap (E=3.26 eV) of rods and plates were found to be nearly identical, but charge transfer varied. X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) analysis revealed that the rods have more pronounced structural oxygen vacancies (Vox, Vo●, and Vo●●) close to the conduction band which lead to electrons trap. On the other hand, the plates relatively have more interstitial oxygen (Oi, Oi', and Oi'') close to the valence band which facilitate hole trapping, reversely increasing the availability of photogenerated electrons and thus resulting in multi-electron transfer reactions. Accordingly, the rods achieved higher degradation efficiency of both methylene blue and phenol than the plates while the opposite was observed for hydrogen evolution. Therefore, ZnO rods can be a relatively good material for production of OH radicals that require degradation of environmental pollutants, whereas ZnO plates can be used for the system that require multiple electron transfer reaction such as energy production via hydrogen evolution.

Background Increasing renewable electricity leads to moments of overproduction coupled to points in time for which not enough production is available to fulfill the needs. In a scenario of 100% renewable energy, about 20% of the yearly production will need to be stored to keep the system in balance. Since the Antwerp-Rotterdam-Rhine-Ruhr (ARRR) cluster is the European region where the highest CO2-emissions are measured (highest production, but also highest population density and energy supply), this region is well positioned to focus on CO2 and 'peak shaving' of renewable energy. Since it is also one of the biggest chemical clusters, the conversion of CO2 into new molecules makes sense guaranteeing that the final balance on energy use and CO2-emissions are lower than in the classical production. We have started an initiative to explore technologies for converting CO2, preferentially coupled to 'peak shaving', to building blocks for the chemical sector. Microbial Electrosynthesis Generation of electric current from the metabolism of organic substrates in microbial fuel cells (MFCs), using bacteria as electrocatalysts was reported. By converting the chemical energy stored in organic substrates to electricity, MFCs can reduce the operational cost of wastewater treatment plants. Recently, a new concept of microbial electrosynthesis has evolved where similar setups, generally known as bioelectrochemical systems (BES), are being used for the production of chemicals. Already the bioelectrochemical reduction of CO2 to acetate has been achieved, as well as the reduction of CO2 to methane and multi-carbon compounds. Efforts are underway to utilize a wide variety of substrates for production of an array of compounds. The key advantage here is the use of excess electricity that is often generated renewably, from solar cells and wind mills, all of which cannot be utilized immediately and can be fed into BES to produce chemicals. We will report our first results with specific bacteria towards bioelectrochemical conversion of CO2 to organic compounds. Acetogens like Sporomusa and Clostridium sps. were experimented for their CO2 reduction capacity at -0.6 V vs Ag/AgCl cathode potential. Adjustment of reduction potential and optimization of cell conditions were carried out in a fed batch reactor with an activated carbon cathode. Production of 67 mg/L ethanol with mixed culture as biocatalyst was the most remarkable achievement. Enzymatic Electrosynthesis Enzymes can also be used for chemical transformations including both the reduction and oxidation reactions. We are using CO2 as substrate for the production of methanol which will have a significant positive impact on environment as well as energy crisis. Electrosynthesis of formic acid was higher at an operational voltage of -1 V vs. Ag/AgCl (9.37 mg L-1 CO2) compared to operation at -0.8 V (4.73 mg L-1 CO2) which was strongly supported by the reduction catalytic current. Voltammograms also depicted a reversible redox peak throughout operation at -1 V, indicating NAD+ recycling for proton transfer from the source to CO2. Product saturation was observed after 45 minutes of enzyme addition and then reversibility commenced, depicting a lower and stable formic acid concentration throughout the subsequent time of operation.

Educational buildings form a major part of public buildings in the Kingdom of Saudi Arabia (KSA) as is true for many Middle Eastern countries in the region. As a result of the rapid growth in the KSA, prototype educational buildings are designed with little or no effort towards standards of energy efficient design, and therefore are considered to be one of the highest energy consumers in the country. Educational buildings are unique facilities accommodating a large number of people and services for the purpose of learning, propagation of knowledge and the development of skills for life. Hence, the energy efficiency of educational buildings has now become a priority for educational organisations, design professionals and particularly governments with visions for sustainable development. The main objective of this study is to assess the energy consumption of typical Higher Technical Institutes (HTIs) buildings in five different cities representing different climatic zones of the KSA. The investigation will evaluate the total energy consumption of a prototype building design and its response to the climate conditions in each region. In this study, a whole building energy simulation was used to investigate the sensitivity of various factors affecting energy use and a detailed computer model of a prototype building in five different cities in the KSA have been constructed using EnergyPlus thermal analysis engine through DesignBuilder software package. The results revealed that the energy consumption in investigated prototype educational building differed significantly because of each city location of the project. Moreover, it was found that the variations in the total energy consumption between the five selected cities were a result of the consumption of the cooling and heating systems. The study emphasised on the total energy consumption of educational buildings demonstrating a prototype HTIs building as a case study and concluded that the KSA would require its own building energy benchmarking classification system if it is to develop best or good practice energy standards for buildings within the country. Moreover, to optimise the energy consumption in educational buildings, each region should have its own guidelines according to the climatic conditions within the KSA, which is also applicable to other types of buildings.

The role of using Forward Osmosis (FO) or Nano filtration (NF) as a pre-treated method to the existing MSF desalination plants is to reduce divalent ions which cause hard scale deposition at elevated temperature. The separation of divalent ion enables to increase the desalination process temperature greater than 110 0C which consequently increases the plant performance, increase the productivity as well as reduce the chemical consumption. Integration of NF system to existing MSF desalination plant and treatment of only 30% of make-up enable to increase the TBT up to 130°C, the production can be increased to 20%. The cost analysis showed the unit product cost is 5.4% higher than that conventional MSF (at 110°C) due to the additional capital cost of NF system. Integrating NF system to novel configuration (NF-MSF-DM) desalination plant at the TBT = 130°C, the gain output ratio could be as high as 16, i.e. double the convention MSF-BR. The new NF-MSFDM configuration significantly reduces the unit's input thermal energy to suit the use of (the relatively expensive) solar energy as a desalination plant driver. Integrating FO to existing MSF and use the brine of the last stage as a draw solution at a recovery ratio of 35 % reduces the Ca+ ions in the seawater feed by 20 % which enables to increase the TBT up to 130 0C safely. The simulation results show at TBT = 130 0C, the production of the existing MSF plant increases by 20 %. The OPEX analysis showed an amount of 2.3 M$/Year of chemical cost can be saved if the FO deployed to the existing MSF plant in Qatar. The trade off point between the additional CAPEX of FO membrane system and saving in OPEX will be considered under different operating condition in the present work.

A great challenge for this century lies in cleaning-up the wastewater generated during industrial, domestic and agricultural activities before being released, into the aquatic environment, or reused for another purpose e.g. irrigation. Phenolic compounds among the various organic contaminates found in wastewater require special attention because of their toxic effect on humans and the environment. Their presence has been confirmed in many different industrial wastewaters. These phenolic compounds are refractory ones and the efficiency of their traditional treatment techniques is low. Therefore, the use of an effective and economic elimination technique for phenolic compounds in wastewater becomes an urgent demand. Advanced oxidation processes (AOPs) represents the most recent technology in wastewater treatment. TiO2 is known to be an excellent photocatalyst. However, there are some challenges regarding using TiO2 in the industrial scale. Significant attention is directed towards using carbonaceous nanomaterials as support to enhance photocatalytic behavior of TiO2 due to their unique and controllable structural and electrical properties. In this work, low percentage of reduced graphene oxide (RGO) and graphene oxide (GO) were supported on TiO2 seeking a better catalytic performances. These composites were tested for degrading some phenolic compounds using UV as photoexcitation source in presence of some oxidants e.g. H2O2. It was found that small loadings of GO and RGO decreased the band gap energy for TiO2 and increased the efficiency and decreased the time needed for the photodegradation of phenolic compounds.

Desalinated seawater is the primary source of drinking water in Qatar. Among all present desalination technologies, reverse osmosis (RO) has been demonstrated as one of the most feasible processes. However, the main limitation with RO and other membrane-based techniques is costly operation and maintenance associated with membrane scaling, fouling, and degradation. Advanced membranes that enable ultrafast permeation while maintaining good mechanical properties, are very important to facilitate both water purification and desalination technologies. Low-dimensional nanomaterials such as carbon nanotubes, cellulose nanocrystals and graphene oxide (GO) have been tested in membranes due to their good mechanical properties and amenable surface functionalization. Specifically, GO nanosheets have recently emerged as a new material for ultrathin, high-flux and energy-efficient sieving membranes due to GO's unique two-dimensional atomically thin structure, outstanding mechanical strength and good flexibility, as well as good dispersion in aqueous solutions. However, selectivity and stability of fully wetted GO membranes in cross-flow conditions has remained challenging and solubility of GO can also lead to membrane disintegration under operation conditions. Herein we present MXenes [1], a new class of 2D carbides, as new promising membrane materials for water desalination applications. For this purpose, Ti3C2-based MXene membranes have been prepared by a vacuum-assisted filtration technique. In order to detect the permeated ions and molecules, we have performed electrical conductivity measurements and UV-Vis analyses. The results have shown that MXene membranes are selective towards ions of different size/charge, such as Cu2+, Mg2+, Na+, K+, SO42-, and Cl-. The permeation data have also shown a cut-off trend around 4 Å, and species of a larger size have been sieved out. The transport mechanism through MXene membrane films has been therefore size and charge selective due to the presence of the interlayer slit pores and the negative charges on the hydrophilic Ti3C2-based MXene film surfaces. In this study, we compare MXene membranes with GO membranes to better understand differences in their water desalination performance. Indeed these novel membrane composites are expected to improve the flux, increase the salt rejection efficiency and decrease adhesion of the adsorbed particulates and organic molecules, thus mitigating fouling. Reference: 1.M. Naguib, V.N. Mochalin, M.W. Barsoum, Y. Gogotsi, MXenes: A New Family of Two-Dimensional Materials, Advanced Materials, 26, 992-1005 (2014)

Dispersed water droplets in organic liquids are commonly encountered in the oil, chemical and biochemical industries. A typical example is the separation of dispersed water drops in crude oil, in order to prevent catalyst fouling, viscosity and volume increase, and to meet quality specifications of the crude oil. Water drops can be removed from a continuous oil phase by various techniques, such as chemical demulsification, gravity or centrifugal separation, pH adjustment, filtration, heat treatment, membrane separation and electrostatic-enhanced coalescence. Compared to other methods, electrical demulsification is considered to be superior in terms of energy efficiency. The electrostatic effects arise from the much higher values of dielectric permittivity and conductivity of water in comparison to oil. However, the mechanism of electrocoalescence is still not fully understood and most of the conventional electro-separators are rather bulky. There is, therefore, a compelling need to optimize the design and operation of these separators by means of a better fundamental understanding of the underlying physics. This study aims at investigating the coalescence behaviour of water droplets in sunflower oil when the aqueous phase is present in the form of a chain of droplets. Chains easily form in an emulsion, since droplets tend to align themselves with the direction of the electric field. A pair of ladder-wise electrodes was implemented to set up an electric field almost parallel to the flow direction of the droplets. This design ensures that adjacent droplets in a chain experience the maximum attractive force and does not significantly disturb the hydrodynamics of the continuous phase. The effect of the electric field strength, frequency and waveform on the process performance has been investigated. Both constant and pulsed dc fields have been applied to the dispersion. Sinusoidal, sawtooth and square waves have been employed as pulsed dc waveforms. Droplet size distributions at the outlet of the device were measured by image analysis. The outcomes of the research suggest that it is possible to find a combination of electrical field intensity, frequency and waveform to maximize the separation efficiency.