Qatar Foundation Annual Research Conference Proceedings Volume 2018 Issue 1
- تاريخ المؤتمر: 19-20 Mar 2018
- الموقع: Qatar National Convention Center (QNCC), Doha, Qatar
- رقم المجلد: 2018
- المنشور: ١٢ مارس ٢٠١٨
1 - 20 of 142 نتائج
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Novel low band gap polymers based on pyrrolo[32d:45d’]bisthiazole PBTz and thienylenevinylene TV For Organic Electronic Applications
المؤلفون: Dhananjaya Patra, Hassan S Bazzi, Lei Fang and Mohammed Al-HashimiNovel low band gap polymers based on pyrrolo[3,2-d:4,5-d′]bisthiazole (PBTz) and thienylenevinylene (TV) For Organic Electronic Applications Dhananjaya Patra?,1 Hassan S. Bazzi,1 Lei Fang¬2 and Mohammed Al-Hashimi1 1Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar 2Department of Chemistry and Department of Materials Science and Engineering, Texas A&M University, College Station, TX. Corresponding author: [email protected] π-Conjugated organic polymers have been intensively studied over the past two decades due to their potential applications in areas such as organic light-emitting diodes (OLEDs),1 organic thin-film transistors (OTFTs), organic photovoltaics (OPV), and organic laser devices. In addition, they possess excellent properties that enable them to be solution processed offering a path-way for fabrication on large-area printable and cost-effective flexible electronic devices. Several donor-acceptor (D-A) conjugated polymers and small molecules are reported recently with photovoltaic performance over 12%.2-4 Recently significant development has been made in the design and synthesis of high performance polymers with mobilities now easily surpassing μ > 1 cm2 V-1 s-1.5 Among the various conjugated electron-donating building blocks, thienylenevinylene (TV) unit has attracted much interest owing to its coplanarity and extended π-conjugation which are induced by the presence of a vinylene spacer between the two thiophene units. As a result this enhanced interchain interaction the polymers exhibit a higher hole mobility and reduced energy band gaps.4 Recently, the incorporation of vinylene unit into several electron-rich (i.e., donor) and electron deficient (i.e., acceptor) units has been widely studied, especially, targeting at the device application for n-channel and ambipolar OTFTs with promising device performance. Among these units are diketopyrrolopyrrole (DPP), benzoselenadiazole (BSe), phthalimide (PhI), naphthalenediimide (NDI), benzothiadiazole (BT), dithienothiophene (DTT), thienopyrroledione (TPD), and isoindigo (iI) as depicted in Figure 1. For instance, Yoo et al. reported the synthesis of various polymers based on DPP and (E)-2-(2-(thiophen-2-yl)-vinyl)thiophene units by altering the number of thiophene in the repeat unit to induce strong π–π stacking and favorable molecular conformation. By replacing the thiophene unit with the selenophene vinylene selenophene Kang et al. reported an enhanced mobility. Several DPP and TV based polymers reported by Oh and Kim et al. via various side-chain engineering on the DDP units, obtained remarkable mobilities from 8.74 to 17.8 cm2 V − 1 s − 1.5 Reichmanis and co-workers also reported the synthesis of a series of BT oligothiophene and oligo-TV donor-acceptor (D − A) copolymers exhibiting mobilities of up to 0.75 cm2 V − 1 s − 1. Kim and co-workers reported the synthesis and characterization of highly soluble poly(thienylenevinylene) exhibiting carrier mobility of 1 cm2 V − 1 s − 1.6 Al-Hashimi, Heeney and co-workers systematically investigated the role of modifying the heteroatom, by synthesizing a series of vinylene copolymers containing 3-dodecylthiophene, selenophene and tellurophene.7,8 Figure 1. Structures of thiophene (Th), thiazole (Tz) diketopyrrolopyrrole (DPP), benzoselenadiazole (BSe), phthalimide (PhI), naphthalenediimide (NDI), benzothiadiazole (BT), dithienothiophene (DTT), thienopyrroledione (TPD), and isoindigo (iI). Another particularly promising class of building block for the development of high performing polymeric semiconductors for OTFTs is the electron-deficient pyrrolo[3,2-d:4,5-d′]bisthiazole (PBTz)-based heterocycle. In comparison to dithienothiophene (Figure 1), PBTz-unit is a weak acceptor having an electronegative nitrogen atom, which lowers the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies. Therefore, it is expected that the large polarity of the thiazole ring can enhance the intermolecular interaction. In addition, the bridging nitrogen (N) of PBTz offers the opportunity to include an additional solubilizing sidechain, which is not present in the analogous DTT. This potentially offer improved solubility and processability of the polymers. Nonetheless, to the best of our knowledge, there is no single report on the synthesis, polymer characterization, and charge carrier transport properties employing the fused PBTz containing TV units. In this work, we report the synthesis and characterization of a series of four PBTz-TV-based copolymers P1-P4 (Scheme 2) with various alkyl side chains for OTFT applications. Particularly, we have selected a dodecyl alkyl side chain on the thienylenevinylene unit, three branched alkyl side chains such as 2-octyldodecyl (OD), 9-heptadecyl (HD) and 2-ethylhexyl (EH), and a long straight n-hexadecyl (HD) chain on the nitrogen of the pyrrolobisthiazole unit, thus, for improving polymer solubility and effectively to promote π − π interchain interactions. The electrochemical redox properties and related electronic structures (HOMO/LUMO energy levels) were systematically investigated by cyclic voltammetry (CV). In addition, the microstructure and morphology of the polymer thin films were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). Finally, the PBTZ-copolymers show band gaps in the range of 1.40 − 1.46 eV and mobilities in the range of 0.002-0.062 cm2 V − 1 s − 1 in bottom-gate/top-contact OTFTs.9 References. 1. Burroughes, J. H.; Bradley, D. D. C.; Brown, A. R.; Marks, R. N.; Mackay, K.; Friend, R. H.; Burn, P. L.; Holmes, A. B. Nature, 1990, 347, 539. 2. Sekitani, T.; Zschieschang, U.; Klauk, H.; Someya, T. Nat. Mater.,2010, 9, 1015.3. Zhao, W.; Li, S.; Yao, H.; Zhang, S.; Zhang, Y.; Yang, B.; Hou, J. J. Am. Chem. Soc., 2017, 139, 7148. 4. Li, N.; Baran, D.; Forberich, K.; Machui, F.; Ameri, T.; Turbiez, M.; Carrasco-O., M.; Drees, M.; Facchetti, A.; Krebse, F.C.; Brabec, C. J. Energy Environ. Sci., 2013, 6, 3407. 5. Kim, J.; Lim, B.; Baeg, K. J.; Noh, Y. Y.; Khim, D.; Jeong, H. G.; Yun, J. M.; Kim, D. Y. Chem. Mater.,2011, 23, 4663. 6. Fu, B. Y.; Baltazar, J.; Hu, Z. K.; Chien, A. T.; Kumar, S.; Henderson, C. L.; Collard, D. M.; Reichmanis, E. Chem. Mater.,2012, 24, 4123 7.Al-Hashimi, M.; Han, Y.; Smith, J.; Bazzi, H. S.; Alqaradawi, S. Y. A.; Watkins, S. E.; Anthopoulos, T. D.; Heeney, M. Chem. Sci.,2016, 7, 1093. 8. Al-Hashimi, M.; Baklar, M. A.; Colleaux, F.; Watkins, S. E.; Anthopoulos, T. D.; Stingelin, N.; Heeney, M. Macromolecules, 2011, 44, 5194. 9. Patra, D.; Lee, J.; Lee, J.; Sredojevic, D. N.; White, A.J.P.; Bazzi, H. S.; Brothers, E. N.; Heeney, M.; Fang, L.; Yoon. M.-H.; Al-Hashimi, M. J. Mater. Chem. C., 2017, 5, 2247.
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Concentrated photovoltaic system with a phase change material: A system to harness solar energy more efficiently as compared to a conventional photovoltaic system for Qatar climatic conditions
المؤلفون: Jawad Sarwar, Ahmed E Abbas and Konstantinos E KakosimosConcentrated photovoltaics (CPV) is advantageous as compared to a conventional non-concentrated photovoltaic (PV) system due to its ability to increase PV cell efficiency and replacing expensive PV material with an abundant and inexpensive reflective or refractive concentrator material. In this work, an overall solar to electrical and thermal conversion efficiencies between a concentrated photovoltaic system thermally regulated by a phase change material (CPVPCM) and a PV system is compared for Qatar climatic conditions. The electrical and thermal behavior of both, CPVPCM and PV, systems are simulated using an already developed and validated coupled electrical-thermal and optical model. A crystalline silicon PV cell is selected which has an electrical conversion efficiency of 14% and temperature dependent maximum power loss coefficient of -0.45% K-1 at standard test conditions. The width of the PV cell is 0.015 m for the CPVPCM system while a 6” × 6” PV cell is considered for the conventional PV system. The same footprint of 1 m2 is selected as a physical equivalency criterion for both systems to compare their electrical and thermal output. Therefore, 36 PV cells, connected in series, represents footprint of 1 m2 for conventional PV system while the length and configuration of the PV cell for a CPVPCM system depend on the concentration ratio and type of concentrator to achieve equal footprint of 1 m2. The CPVPCM system uses a parabolic trough concentrator to focus sunlight onto a PV cell. The concentration ratios of 10 × , 15 × and 20 × are considered in this work, which results in lengths of 5.34 m, 3.56 m and 2.67 m to achieve 1 m2 footprint. An increase in incident irradiance density due to concentration instantaneously generates more power from a PV cell in any CPV system. However, it also increases the PV cell temperature and reduces power output because of the temperature dependent negative power coefficient of PV cells. The electrical power output loss due to temperature diminishes the gain in the electrical output due to the concentration of the irradiance. Furthermore, the elevated PV temperature also results in associated degradation mechanisms such as thermal aging, delamination, and mechanical damages. Therefore, cooling of a PV cell in a CPV system is essential to prevent the net power loss and gain the advantages of increased incident irradiance density. Four different commercially available solid-liquid phase change materials (PCM) are investigated for passive cooling of the CPVPCM system. The PCMs absorb and store excess heat during solid to liquid phase change and thereby, regulate the temperature of the PV cell. The heat storage by PCMs also leads to a potential utilization of thermal energy trapped within the PCM. The selection of a PCM depends on its several thermophysical properties such as melting temperature, latent heat of fusion, density, congruency, and stability. In this work, the selected PCMs are Lauric acid, RT42, S-series salt, and ClimSelTM C48 which are reported to have congruency and cyclic thermal stability as per manufacturers' data sheet. The PCMs have melting temperatures ranging from 41 oC to 54 oC and latent heat of fusion in the range of 178 kJkg-1 – 220 kJkg-1. The PCMs are encapsulated inside an aluminum container behind the PV cell. The aluminum container is made of 3 mm thick aluminum sheet having outer dimensions of 0.105 m × 0.042 m and inner dimensions, to contain PCM, of 0.099 m × 0.036 m. The lengths of the aluminum container are 2.67 m, 3.56 m and 5.34 m for concentration ratio of 20 × , 15 × and 10 × respectively. Two consecutive days of each month of a year are selected to simulate the optical, thermal and electrical behavior of both systems. The direct beam irradiance is obtained using the clear sky Bird's model while weather conditions such as ambient temperature and wind conditions are obtained from experimentally measured data from Qatar meteorological department. Since single axis tracking is a pre-requisite for parabolic trough concentrator; therefore, single axis tracking for PV system is considered as well to achieve equivalency regarding input conditions as well. The temperatures of the PV cells, IV curves to calculate maximum power point, the instantaneous power produced over a day using maximum power point tracking, total power produced over a day, and thermal energy storage in the PCMs are predicted by performing simulations of the electrical, thermal and optical behavior of both systems. It is found that the salt performs better than all other selected PCMs due to its high-energy storage density. The electrical output of the CPVPCM for concentration ratio of 10 × and 15 × is greater than the PV system and comparable at a concentration ratio of 20 × . However, the CPVPCM also store thermal energy, therefore, achieves higher overall solar to the electrical and thermal conversion efficiency as compared to the conventional PV system. Further studies are required, using experimentally measured irradiances instead of using a clear sky model, to investigate and compare the overall conversion efficiencies of the CPVPCM and conventional PV systems.
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Longterm Seasonal Variability of Photovoltaic Surface Soiling and Subsequent Power Loss in Doha Qatar
المؤلفون: Wasim Javed, Bing Guo, Benjamin Figgis and Yiming WubulikasimuDust accumulation or soiling on solar panels' and collectors' surfaces has become a well-known problem, which severely reduces the performance of solar energy conversion systems. The soiling of the solar surfaces is a complex phenomenon influenced by various site-specific environmental and weather factors, and therefore should demonstrate seasonal and weather-dependent trends. Such information of natural PV soiling would be useful not only for modeling the economic impact of surface soiling but also for properly scheduling of cleaning, which is of interest to project developers and operators. The purpose of the study is to investigate the long-term seasonal patterns of airborne dust accumulation on PV modules and soiling-induced PV performance degradation in the desert environment of Qatar. PV performance, ambient dust concentration and meteorological data were collected over the study period of 2014-2017. Results revealed that PV performance due to soiling in terms of daily change in the cleanness index (ΔCI) varied with season, which was attributed to substantial variations in environmental conditions (i.e., rainfall, wind speed, humidity, temperature, airborne dust concentration). Averaged over the four years, the daily ΔCI was − 0.43 ± 1.0% per day for modules cleaned every sixth month, and − 0.46 ± 1.05% per day for modules cleaned every second month or about 14% per month. The annual pattern shows significant seasonal variation of daily ΔCI and cumulative CI during the study period. Daily ΔCI was found to be the most severe during November ( − 0.75%) and least during June ( − 0.19%). The months correspond to the rainy season (i.e., February to April) have moderate values of ΔCI ( − 0.34%). It was observed that average daily ΔCI by month was decreased with increasing PM10 concentration and humidity and increased with that of temperature and wind speed. The intense dust storm and rainy events taking place on specific days of the month are predominantly responsible for the large month-to-month variations of PV soiling. A yearly soiling trend was also determined that could help to reduce uncertainty in energy yield prediction. Monthly dust deposition on PV modules was also determined gravimetrically, which also showed month-to-month variation following the same trend of monthly PV performance loss. In addition to the environmental factors affecting dust accumulation on PV modules, particle size distribution and chemical properties of the monthly-collected dust were investigated and compared as well.
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Slurry Electrode Properties of Carbon Nanotubes and Graphene for Flow Cell Energy Storage Applications
المؤلفون: Ahmed SodiqRedox Flow Batteries (RFBs), among other options, is uniquely suited for large-scale Electrical Energy Storage (EES) due to many advantages over the conventional sealed batteries (e.g., lead-acid and Li-ion batteries). Owing to its design flexibility, flow batteries can meet a wide range of commercial-scale EES applications with varying power-to-energy ratios. In addition, flow batteries have excellent energy efficiency and competitive life-cycle cost and are considered to be inherently safer compared to conventional sealed batteries. Despite its attractiveness and demonstrated performances, flow battery technology still suffers from high system capital cost (which limits its potential deployment into grid storage applications) and low energy density of the reactant fluids (which leads to large footprint and makes it impractical for EES applications with confined spaces). These challenges can be addressed if higher energy density and cheaper battery materials are developed. An attractive approach has been recently proposed, where the active materials are mixed with carbon to create a flowable electrode (otherwise known as slurry electrode). This system helps to operate flow battery with increased concentration of redox species and as a result the energy density is significantly improved.Slurry electrode (shown in Fig. 1) has been defined as “a suspension of particles with large double-layer capacity, such as activated carbon, in an electrolyte solution” [1]. These particles transfer charge from an electrochemical cell to an external reactor, where a substance is oxidized or reduced, and are recharged in the cell [1]. Unlike conventional RFB system, the semi-solid technique uses fluid electrodes that are electronically conductive [2]. Slurry electrodes are characteristically dynamic, particles continuously move and continuously make and break contact with one another. Percolation theory defines a critical loading, fc, above which there are enough particles in the slurry that, at any point in time, a constant network of particles is formed that spans the distance from one boundary to another [3]. It is due to these networks of percolated particles that slurries (with sudden increase in conductivity and viscosity at percolation) are able to conduct electrons out into the electrode and away from the current collector to utilize the high surface area of the particles for electrochemical processes [4, 5]. Other advantages of slurries involve their ability to have high surface areas, simple assembly and ease of maintenance through filtering (for example the carbon materials can be recycled without necessarily opening up the cell). The performance of slurry-electrode-based flow batteries highly depends on the features of the interaction between the particles and current collectors. Parameters such as storage duration or maximum power can be tuned by adjusting the properties of the slurry, being extremely important are the ionic and electrical conductivities of the slurries. Figure 1 In this presentation, the performance of slurry electrodes, based on carbon and redox systems (Vanadium/CNTs and Vanadium/Graphene), focusing in particular on electrochemical performance, conductivity, corrosion, and cell performance will be presented. We achieved high electrochemical activities in the case of Vanadium/CNTs as compared with Vanadium/Graphene as shown in Fig. 2. According to the structural features of the CNTs; the oxygen functional groups improve the hydrophilicity of the electrode. The O = C-OH groups on the CNTs probably behave as active sites, and facilitate the reactions of VO2+/VO2+ redox couple. Figure 2 References [1] B. Kastening, et al., «Design of a slurry electrode reactor system,» Journal of applied electrochemistry, vol. 27, pp. 147-152, 1997. [2] Z. Li, et al., «Aqueous semi-solid flow cell: demonstration and analysis,» Physical Chemistry Chemical Physics, vol. 15, pp. 15833-15839, 2013. [3] L. Gao, et al., «Effective thermal and electrical conductivity of carbon nanotube composites,» Chemical Physics Letters, vol. 434, pp. 297-300, 2007. [4] T. J. Petek, et al., «Characterizing Slurry Electrodes Using Electrochemical Impedance Spectroscopy,» Journal of The Electrochemical Society, vol. 163, pp. A5001-A5009, 2016. [5] H. Parant, et al., «Flowing suspensions of carbon black with high electronic conductivity for flow applications: Comparison between carbons black and exhibition of specific aggregation of carbon particles,» Carbon, vol. 119, pp. 10-20, 2017/08/01/ 2017. [6] H. Yoon, et al., «Pseudocapacitive slurry electrodes using redox-active quinone for high-performance flow capacitors: an atomic-level understanding of pore texture and capacitance enhancement,» Journal of Materials Chemistry A, vol. 3, pp. 23323-23332, 2015.
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Biomass distribution and soil characteristics along the distance from the coast in a natural mangrove forest in Qatar
المؤلفون: Yowhan Son, Hanna Chang, Seung Hyun Han, Jusub Kim and Juha AlataloMangrove is a woody plant which grows in intertidal zones. Mangrove forests are mainly distributed in subtropical and tropical regions, and are valuable for ecosystems and for society. Even in dry regions such as Qatar, mangrove forests provide ecosystem services despite their small area and low productivity compared with tropical mangroves. Carbon sequestration by mangroves is one of the main ecosystem services mitigating climate change, as mangrove forests are carbon-rich ecosystems. In mangrove forests, there is a natural gradient in soil environments between land and sea. Soil salinity and water availability are the major factors influencing mangrove productivity. The objectives of this study were (1) to investigate the change in biomass of Avicennia marina, the only mangrove species in Qatar, along the distance from coast and the relationship between biomass and soil characteristics, and (2) to estimate carbon storage of biomass in a natural mangrove forest in Qatar. Three plots were established in a natural mangrove forest of A. marina in Al-Thakira, Qatar (25°42»15.9»N 51°32»18.4»E), at a distance of 0 m (D0), 50 m (D50), and 100 m (D100) from the coast. Plot size was 2 × 2 m2, 3 × 3 m2 and 4 × 4 m2 at D0, D50, and D100, respectively. Plant abundance was determined by counting the number of individual seedlings ( ≤ 1.3 m high) and trees (>1.3 m high) per plot. Diameter at breast height (DBH) was measured on trees in each plot, and above-ground biomass (AGB) and below-ground biomass (BGB) of trees were estimated using allometric equations for A. marina. Carbon storage in biomass was calculated by carbon fraction of 45.1%. Soil samples at 0-10 cm depth were collected at three random points per plot. Soil samples were air-dried and sieved through a 2 mm mesh screen, and then pH, salinity, water content and nitrogen (N) concentration of each soil sample were measured. Differences in biomass of trees, pH, salinity, water content and N concentration of soil at each distance were analyzed using t-test (SAS 9.4 software). Seedling abundance (no. m-2) was 2.4 ± 0.1 at D0, 7.9 ± 0.8 at D50, and 1.9 ± 0.2 at D100, while tree abundance was 0.9 ± 0.1 at D50 and 1.2 ± 0.1 at D100. There were no trees at D0, so comparisons with this site were excluded. AGB was significantly higher at D100 (41.4 ± 1.9 Mg ha-1) than at D50 (7.3 ± 0.9 Mg ha-1). BGB was higher at D100 (44.9 ± 0.6 Mg ha-1) than at D50 (19.4 ± 2.3 Mg ha-1), but there was no significant difference between two distances. Salinity, water content, and N concentration of soil were 125.1%, 196.3%, and 114.5% higher, respectively, at D100 than at D50 (all differences were significant). Soil pH was significantly 3.1% lower at D100 than at D50. It was reported that growth and biomass of mangroves increased slightly and then decreased continuously along the salinity gradient. However, salinity at the study site was low compared with that in other mangrove forests and might be within the range that biomass increases with salinity. A. marina required a large amount of water and nutrients in high salinity condition (Naidoo, 2009). High water content and N concentration of soil at D100 could meet the requirement for water and nutrient in high salinity condition, and thereby result in the biomass increment. In this study, carbon storage (Mg C ha-1) was 7.3 ± 1.1 for AGB, 9.7 ± 1.1 for BGB, and 18.1 ± 2.4 for total biomass of A. marina. These values are lower than those reported for A. marina in temperate regions (AGB: 57.7 Mg C ha-1, BGB 69.8 Mg C ha-1), subtropical regions (AGB: 49.6-73.1 Mg ha-1, BGB: 49.2-56.8 Mg ha-1), and even dry regions (20.7-66.6 Mg C ha-1). To conclude, biomass of A. marina increased as the distance from the coast and was affected along the gradient of soil characteristics. A better understanding of mangrove biomass distribution between land and sea will contribute to estimate biomass and carbon storage in intertidal zones. * This study was supported by Korea Ministry of Environment (2014001810002).
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Geographical distribution of air pollution in Doha Qatar
المؤلفون: Mariem Safi and Elnaiem Ali ElobaidUrban air pollution is an inevitable consequence of the urbanization representing a growing concern to scientists, policymakers and an increasing fraction of the population. Air pollution is an acute problem especially in the developing countries, where the growing population, developing industry and improving life standards are generating environmental challenges. The State of Qatar has witnessed unprecedented rapid economic growth, and fast development and urbanization during the last few decades, accompanied as usual, by heavy construction and mega scale projects, resulted in adverse environmental effects. Air pollution represent one of these major effects and challenges. Direct exposure to volatile organic compounds VOCs implies public health concern. Even low concentrations of VOCs have been associated with damage to the central nervous system (CNS). The CNS is the primary target organ for toluene toxicity in both humans and animals for acute (short-term) and chronic (long-term) exposures (HMDB, 2014). Benzene is a known human carcinogen and is linked to an increased risk of developing lymphatic and hematopoietic cancers, acute myelogenous leukemia, as well as chronic lymphocytic leukemia (EPA, 2004). Information regarding ambient VOCs exposure is limited in Qatar and in the whole Gulf region in terms of values and types of compounds; however, it can be expected that the concentration values are elevated as they are regarding the other combustion related components such as CO, NOX, SO2 and black carbon (Qatar Environment Statistics Annual Report, 2014). The ozone concentration is also often exceeding the limit value due to the intensive photochemical processes induced by the strong sun radiation and the presence of ozone precursors. The main sources of the critical VOC pollutants in the atmosphere- Benzene, Toluene, Ethylbenzene, and Xylenes- referred to as BTEX, are the motor vehicle exhausts, emissions from the use of solvents, and emissions from the chemical and petroleum industries. This study was an attempt to assess and evaluate the impact of traffic and nearby industry on the air quality of Doha by studying the most important combustion related volatile organic compounds such as BTEX, and atmospheric trace gases (NO, NO2, O3 and NH3). The research aims have been accomplished by conducting two sampling campaigns across the area of Greater Doha with 14 different locations at the main access roads and remote areas during two weeks sample collection period; from February 29, 2016 to March 15, 2016; and from March 16, 2016 to March 31 2016, to quantify the ambient air levels of these pollutants. Passive absorption (diffusion) tubes were used in this campaign because of their mobility, applicability and affordability for outdoor air sampling, as they are easy to handle and require cheap and user-friendly equipment (Buczynska, 2009). Concentrations from most components indicated hot spots roads at the south more than the north of Doha in which BTEX ranged from 7.68-40.5 μg/m3, NO from 7.97-170.4 μg/m3, NO2 from 41.5-105.5 μg/m3 and NH3 was ranged from 8.87-30.4 μg/m3. On the other hand, ground level ozone (O3) depleted at the air pollution hotspots showing higher concentrations at the northern part of the city with a range from 12.1-70.9 μg/m3. Among the samples, the maximum NO2 level was lower than Qatari environmental executive law of 150 μg/m3 on average period of 24-hours. Also, the maximum benzene concentration was 3.15 μg/m3 less than the standard of 5 μg/m3 established by European Community (EC). Visualization of the results has been performed using demonstration hotspot multilayers maps, overlaid in Google-Earth, showing the geographical distribution of the concentration of each individual component. The anticipated continuation of this research will be accomplished by increasing the sampling points and conductive more extensive survey in order to get more representative data with higher spatial resolution. The resulted air quality maps will be essential tools in the hands of policy and decision makers, as a contribution to the current efforts to improve air quality in urban areas. The authors would like to thank Qatar National Research Fund (QNRF) for funding and supporting this project under the National Priorities Research Program (NPRP) award number NPRP 8-202-3-043. Refreneces: Buczynska, A. J. (2009). Atmospheric BTEX-concentrations in an area with intensive street traffic. Atmospheric Environment, 311–318. Committee on Tropospheric Ozone, N. R. (1991). Rethinking the Ozone Problem in Urban and Regional Air Pollution. Washington, D.C.: NATIONAL ACADEMY PRESS. EPA. (2004). EPA Air Toxics. Retrieved from https://www.epa.gov/sites/production/files/2016-09/documents/toluene.pdf HMDB. (2014). Human Metabolome Database. Retrieved from http://www.hmdb.ca/metabolites/HMDB0001505
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Travel Time Estimation using Multivariate Regression Model
المؤلفون: Khaliqur Rahman, Shoaib Mallick and Muhammad AsifAs it is known from the current research and studies that travel time of vehicles is the most reliable parameters to measure the cost of a link. Cost modeling of routes has many useful applications in dynamic route selection strategies e.g. route selection for emergency vehicles. Travel time of an individual vehicle passing a road segment is a function of many parameters which includes of road geometry, traffic flow characteristics, driver»s behaviors and region-specific rules and regulations, length of the segment, number of lanes, lane width, traffic flow, traffic volume and density, average speed of vehicles, vehicles composition and the ratio of turn movements on ramps. Moreover, the average travel time of vehicles on freeways is also dependent on some parameters that vary from country to country e.g. traffic regulations, driving rules, driver»s behavior and the construction of roads. Current mathematical models and simulation software»s lack the implementation of all these parameters and hence the results of these models are mostly different from the actual. The calibration of simulation software is always required to reduce this difference. The estimation of travel time using some numerical computation or simulation software»s is not reliable. This paper describes the modeling of travel time as a cost/metric of segments on a freeway. In it, regression models are used to evaluation the travel time for a throughway segment using traffic statistics acquired from field surveys. The validity of the models is explained with their statistical significance. Regression models are equally beneficial for any region if the data sets are quite large and enough parameters are included in the model. In regression analysis, the relationships among different variables are estimated. In it, different modeling techniques are used to find the relationship between dependent and independent variables. More precisely, the analysis helps to realize how the dependent variable changes with the variation of any of the independent variables keeping other variables fixed. In this work, statistical techniques i.e. regression modeling and analysis of variance (ANOVA) has been used to evaluate the impact of each independent variable (parameters) on the travel time. Finally, a multivariate regression model is used to approximate the time of travel. The estimated time is related to the actual travel time from the real field data and the model fitness is evaluated. Our dataset constitutes of four independent parameters and one dependent parameters. Independent variable (Inputs): 1 Length of the segment 2 No of lanes in the segment 3 Flow of traffic on the segment 4 Average Speed of vehicles on the segment Dependent variable (Response) 1 Travel Time Regression analysis has been used as a statistical technique to find the response variable (travel time). In this paper it is proposed to find the travel time for a particular connection using regression models applied to actual traffic data sets collected from field surveys. Real traffic data for several segments from different freeways has acquired and analyzed them using regression models. The probable travel time was compared with actual travel time for each segment of the highway and it was found that the estimation using regression models reveals the significant level of accuracy. R-Studio is being used in the statistical analysis of the data. We computed the regression equation for the estimation of travel time for all the given four parameters (distance, lanes, flow, speed) using coefficients, β0, β1, β2, β3 and β4. Figure1 shows the actual travel time of the vehicle and the estimated travel time which is obtained by the regression analysis.
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Indoor and Outdoor Air Pollution in Doha – cases of schools and residences
المؤلفون: Balint AlfoldyThe World Health Organization (WHO) attributes air pollution to 1 in 8 deaths worldwide, where exposure to indoor air pollutants is a significant contributor to incidences of heart disease, respiratory problems, and cancer (WHO, 2014). Since people spend the major part of the day indoors - especially in Qatar -, indoor air quality (IAQ) is a significant factor affecting their overall pollutant exposure via the respiratory-inhalation pathway. IAQ is mainly determined by the geographical location of a building, its proximity to outdoor pollutant sources such as industry, construction activities, traffic or natural pollutant sources (e.g. desert sand particulates), as well as the building characteristics itself (building envelope, air tightness, ventilation/air conditioning system). Indoor sources like decoration and furniture, as well as indoor activities like cleaning and cooking also affect IAQ. Recently, the WHO ranked Qatar second position worldwide of countries with the highest ambient PM2.5 exposure (WHO, 2014). The issue can therefore be regarded as of great significance to public health for the citizens of Qatar, and therefore warrants scientific study and potential mitigation of excessive PM2.5 exposure. In particular, the young citizens of Qatar are especially susceptible to the impacts of PM2.5 inhalation due to their early stage of physiological development. A building can function as a protective shelter for poor outdoor air quality, but without a dedicated IAQ enhancement strategy, buildings may not automatically lead to a reduced indoor exposure to air pollutants, including PM2.5, as well as other potentially harmful pollutants including: oxides of nitrogen and sulphur (NO2, SO2); ozone (O3), natural radiation (radon, Rn); microorganisms (bacteria and fungal spores); a range of volatile organic compounds, and hydrocarbons. This study aimed to characterise IAQ of Qatar's indoor environments, with a particular focus on schools and residences with consideration of outdoor air quality (OAQ) conditions. Simultaneous IAQ/OAQ measurements have been conducted using established reference methods and sampling techniques specifically developed for IAQ studies. PM10, PM2.5 and ultrafine particle concentrations, aerosol size distribution and particle elemental composition have been measured. Volatile organic compounds, aldehydes, NO2, SO2 and O3 were monitored. CO2, temperature and relative humidity were also monitored, and the air exchange rate between indoor and outdoor environments has been assessed. Semi-volatile organic compounds, such as polycyclic aromatic hydrocarbons, phthalates and flame retardants have been quantified in order to identify specific sources of contamination as derived from combustion and/or building material emission sources. Three school classrooms and associated school-pupil homes were selected for conducting IAQ assessments in order to determine pupil exposure levels to air pollutants over a 24-hour period. Volunteers were equipped with personal exposure monitors for determining their location and activity-dependent air pollutant exposure levels. The first measurement campaign of the research project was conducted in May, 2017. Three classrooms were monitored and five residences, as well as the outdoor location in the school's garden. The results indicate that the indoor concentrations of VOCs, aldehydes and PAHs exceeded the outdoor levels, and that pollutants concentration in residences were consistently higher than in the school classrooms. In terms of particulate matter (PM2.5) the opposite trend was observed. The indoor PM2.5 levels were far lower than the reference outdoor concentration. Regarding the comparison of school class rooms and homes, the same trend as in the case of VOCs was observed. Namely, the PM2.5 levels in homes were consistently higher than in the school classrooms. Overall, the results show that indoor environments represent a protective shelter against the outdoor particulate air pollution ion Qatar. The indoor air quality is determined mainly by pollution sources indoors – particularly in residences due to the presence of more intensive and versatile emission sources – including furniture, decorations, use of air refreshers; as well as activity generated emissions by the inhabitants like cooking, cleaning, or smoking. The second measurement campaign will be conducted in December 2017, when new data will be collected under different seasonal conditions i.e. mild temperatures, where buildings typically have more ventilation with the outdoor environment, and where higher ingress of outdoor air pollution may be expected. The authors would like to thank Qatar National Research Fund (QNRF) for funding and supporting this project under the National Priorities Research Program (NPRP) award number NPRP 8-202-3-043.
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Simulation and Optimization of an LNG Plant Cold Section
المؤلفون: Mary Anna Katebah, Mohamed Mamoon Hussein and Easa Ismail AlmuslehSimulation and Optimization of an LNG Plant Cold Section Mary Anna Katebah, Mohamed Mamoon Hussein, Easa I. Almusleh* Chemical engineering department, Qatar University Global energy demands are expected to rise by almost 30% in the next 20 years, with fossil fuels being the primary energy sources. The combustion of fossil fuels yields significant amounts of greenhouse gas emissions, predominantly CO2. Compared to its alternatives (coal and crude oil), natural gas is preferred primarily due to its cleaner burning. The most profitable method of transporting natural gas from the source of production is as liquefied natural gas (LNG). However, LNG plants are associated with relatively large energy demands (mainly compression power) that are costly and result in significant levels of CO2 emissions. Qatar is the largest LNG supplier world-wide, and the plans of increasing production place utmost importance on enhancing the efficiency of LNG plants. With current production of almost 78 million tons per annual (MTA), significant benefits, such as improved economics and lower CO2 emissions, can be achieved even with small efficiency improvements. It is also noteworthy that, for a given power consumption, higher efficiencies can potentially result in more production volumes. Therefore, optimization of LNG processes would assist the country in achieving the aspirations of the Qatar National Vision 2030 by sustaining both economic prosperity and the environment for future generations. Within the LNG chain, more than 75% of the CO2 emissions emanate in the processing plant, where nearly 80% of those emissions are sourced in the cold section of the plant which comprises of the natural gas liquids (NGL) recovery system, the liquefaction process, and the helium extraction and nitrogen removal units. Various natural gas liquefaction cycles exist that employ either pure refrigerant in cascade cycles, multi-pressure cycles, or mixed refrigerant cycles. Among all the available cycles, the propane pre-cooled mixed refrigerant (C3MR) system is the leading one in the LNG industry. Therefore, this research focuses on decreasing the energy consumption of C3MR and NGL recovery system with helium extraction (producing approximately 60 mol% crude helium) and nitrogen rejection units. Initially, a base-case model was developed for the cold section using Aspen PlusTM, a steady-state process simulation and optimization software. A degree of freedom analysis was carried out on the model to identify the operating variables available for optimization. This step also serves to identify the operational and design constraints. Next, a sensitivity analysis was conducted on the variables to construct the operating windows one may operate in and get reduced energy consumption. Parameters that were studied include: scrub column reflux and pressure, mixed refrigerant (MR) composition, propane evaporating pressures, LNG temperature (leaving the main heat exchanger), and helium extraction and nitrogen removal temperature and pressure values. Finally, sequential quadratic programming (SQP) optimization technique was employed to find optimal values for the operating variables that will result in global minimum energy consumption. In addition to this rigorous optimization approach, we have developed an effective shortcut method that can be used for optimization with minimum effort. The method was evaluated and found to be suitable for LNG and other cooling applications. Additionally, an exergy analysis was conducted before and after optimization to quantify the reduction in lost work for main process equipment as a result of the optimization. After investigating optimization options with minimal implementation costs, retrofitting options will be studied to further enhance the process. Simulation of the cold section was conducted for the production of almost 3.65 MTA of LNG. Sweet, dehydrated natural gas at 21°C and 66 bar was pre-cooled by the propane cycle to around − 27 °C before entering a scrub column (i.e. distillation column) that separated the natural gas from the NGL's. Almost 12 thousand barrel/day of NGLs were produced and sent to a fractionation unit to separate ethane, propane and butane. Heavy hydrocarbons, primarily condensate (C5+) leaving the fractionation unit, can be either sold or sent to a close by refinery for further processing. The separated natural gas stream was further cooled and liquefied in the main cryogenic heat exchanger (MCHE) to temperatures near − 140°C. The cooling in the MCHE was supplied by the mixed refrigerant, which was pre-cooled by the propane cycle. LNG then entered the helium extraction (producing almost 60 mol% crude helium) and nitrogen removal units to obtain desired LNG specifications. Final LNG product comprised of 0.7 mol% nitrogen, 90.7 mol% methane, 5.6 mol% ethane, 2 mol% propane, 0.92 mol% butanes, at a temperature and gross heating value (GHV) of approximately − 161°C and 11.5 respectively. Simulation results showed that for the production of 3.6 MTA LNG, the cold section would require a total of around 131 MW of compression power. Main sensitivity analysis results showed that the mixed refrigerant composition was a key parameter in the cycle's performance. Other primary parameters affecting the energy consumption include the propane cycle's evaporation pressures and flowrates. Using the short cut method, optimization revealed that optimized MR composition resulted in almost 10% MR compression power and 6% plant operating cost savings, whereas new intermediate propane evaporation pressures, identified using detailed simulation, and flowrates decreased the propane compression power and operating costs by around 3.6%, and 2%, respectively. *Corresponding author. +974 44034148 E-mail address: E-mail: [email protected] (E. Al-musleh).
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Screening of Fresh water and Sea water Microalgae strains from Qatar for feed supplement production
The worldwide continuous increasing of population provokes an increasing awareness about the food security. Qatar is one of the first countries establishing a Food Security Strategy Program to satisfy the demand of food and feed. Microalgae is considered as one of the most promising solution based on its ability to produce the essential elements needed for food and feed such as lipids, carbohydrates, proteins... In Qatar University, a diverse collection of Microalgae and Cyanobacteria strains isolated from different environments was established (QUCCCM). Microalgae, These photosynthetic microorganisms are capable of converting solar energy into useful compounds. Microalgae accumulate several kinds of metabolites such as proteins (6-52%), lipids (7-23%), carbohydrates (5-23%). In addition, microalgae produce have the ability to produce high-value metabolites. The aim of our work was to screen the QUCCCM and identify potential strains with high nutritional value for use as feed for poultry and livestock. In this study, Microalgal isolates belonging to 12 different species were investigated for their eligibility to be used as a feed. All strains were cultivated over a period of 10 to15 days depending on species. Optical Density and Dry weights were recorded every three days to follow the algal Growth. The results showed the presence of three categories of isolates (fast, medium and slow growing). Among them, the species Chlamydomonas sp. presented the highest growth rate (μ) with 0.89day − 1 ± 0.27 and a doubling time of 1.28/ day. Based on this result, the fast-growing strains were subjected to metabolite investigations in terms of lipids, proteins, carbohydrates, amino acids and Fatty acids to select the ideal strain(s) presenting high growth rate along with metabolites valuable for algae-based feed supplement. The highest protein and Lipid content was observed in the case of a freshwater strain belonging to the Mychonastes sp.with ∼ 50% w/w and 40.7% ± 0.015 respectively. Carbohydrates were seen highest in Chlorococcum sp.with a value of 30% ± 0.009%. Considering the marine strains, the isolates had a similar range of protein, Lipids and Carbohydrates content of (22%-34%), (32%-39%) and (8%-20%) respectively. Based on this study, one marine strain (Pichochloris sp.) having 33% ± 0.021 content of protein and 32.7% ± 0.036 as lipid, and one freshwater (Mychonastes sp.) holding the highest amount of metabolites were selected for deeply investigations in terms of FAME and Amino acid profiling which are crucial parameters that determine the feed quality. The results showed the presence of different essential Amino acids in the total protein fraction. Fatty acid profiling comprised saturated and unsaturated fats for all strains; most of them being rich with C18:0; C16:0 and C16:3. For the selected strains, the metabolite content during the growth period was followed by sampling every 3 days in order to identify the stage having high productivity and rich metabolite content. The analysis of the isolates showed an increase in the production of each metabolite during the growth, wherein lipids and protein amounts are relatively high while carbohydrates were comparatively low. These two selected strains will be improved in terms of lipid and protein production using media and salinity stress in order to enhance the production of essential nutrients such as omegas, amino acids and used for animal bioassay. In Conclusion, this study showed the existence of a diverse and rich collection of valuable strains with important metabolites that can support the country's food security program, by providing microalgae to supplement animal feed. Additionally, the potential candidates can be used for commercial applications.
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Levels of Airborne Bacteria in a School Classroom Environment in Doha Qatar
المؤلفون: Jeffrey P ObbardAirborne bacteria represent a potential risk to human health upon inhalation in both outdoor and indoor environments. Outdoors, bacteria may be derived from a variety of sources including soils, vegetation and animals, whilst indoors sources include both healthy and infected individuals, as well as pets, furnishings and food sources. The aim of this study was to investigate the quantity and size distribution of airborne bacteria inside a school classroom, as well as the outdoor environment, in Doha, Qatar. Air samples were collected from the indoor classroom and outdoor environment at the German International School in the south of Doha, Qatar during two separate sampling periods in 2017 i.e. summer time (15 June) and autumn time (17 October). An Anderson Six-Stage Impactor was used to collect airborne bacteria. The impactor aerodynamically sizes collected microbes in an airstream over six stages (i.e. 7 < ; 7.0 to 4.7; 4.7 to 3.3; 3.3 to 2.1; 2.1 to 1.1; and 1.1 to 0.65 μm diameter, respectively). Bacteria in each size stage are collected on nutrient agar (NA) plates in the impactor. Air samples were collected in triplicate both indoors and outdoors prior to commencement of class at 6:30 AM, and immediately after end of classes at 2:30 PM. Each sample was collected over a 5 minutes period at an airflow rate of 28.3 liters of air/minute i.e. total 141.5 liters of air collected per sample. After sampling, NA plates were then incubated for 24 hours at 37°C. After incubation the number of colony forming units (CFU) of bacteria on the NA plates were counted, and the average of triplicate samples for the morning and afternoon samples were calculated as the mean number of airborne bacteria per cubic meter of air (CFU/m3). The prevalence and concentration of bacteria varied both spatially (indoors versus outdoors), and temporally (morning versus afternoon). In both sample periods i.e. 15 June 2017 and 17 October 2017, the levels of airborne bacteria in classroom air were lowest in the morning i.e. before class (a maximum 204 CFU/m3 in June, and a maximum 35 CFU/m3 in October) than in the afternoon after class (a maximum 348 CFU/m3 in June, and a maximum 543 CFU/m3 in October). As the classroom was continuously occupied between the morning and afternoon, then human influence is the most likely factor affecting prevailing CFU levels. Other factors likely affecting CFU levels may include: airflow dynamics and exchange between the indoor and outdoor environment; the influence of the classroom air-conditioning and ventilation system (positive or negative) and; the presence of non-human bacterial sources in the classroom (food debris, carpeting, soft furnishings etc.). Outdoor air samples showed the opposite profile to the classroom, where morning samples had higher numbers of airborne bacteria in the morning (a maximum 640 CFU/m3 in June, and a maximum 111 CFU/m3 in October) compared to the afternoon samples (a maximum 299 CFU/m3 in June, and a maximum 82 CFU/m3 in October). This contrast supports the indication that airborne bacteria in the classroom are derived from internal sources rather than as a result of infiltration of bacteria from outside. The most prevalent size range of airborne bacteria present in the classroom were in the 1.1- 3.3 μm diameter range for both sample periods (June and October). Such bacteria are typically associated with aerial emission from individuals via coughing, sneezing, and exhalation, and typically represent the greatest potential pathogenic risk in terms of re-inhalation and penetration into the respiratory-lung system. Qatar does not currently have occupational health guidelines for airborne bacteria, but guidelines are available for other countries where similar work has been conducted by the project LPI, Professor Obbard – notably in Singapore. Here, the recommended guideline level for total airborne microbes in indoor air is 500 CFU/m3 for both airborne bacteria and fungal spores. The measurement of 543 CFU/m3 measured for bacteria alone in classroom air in Doha (October 2017), suggests that classroom air quality can exceed such health guidelines for both students and teachers - particularly as the most prevalent size range of the airborne bacteria are in the size range for penetration into the respiratory-lung system. The results of the study show that levels of airborne bacteria in classrooms in Doha become elevated over the course of the teaching day – most likely due to the presence of teachers and students that serve as natural reservoirs of bacteria (both non-pathogenic and pathogenic). Inadequate ventilation of the classroom and/or the air conditioning serving as a source of bacteria could also be a contributor to elevated levels of airborne bacteria in the school classroom. It is also clear that the size distribution of the airborne bacteria is predominated by bacteria in the smaller size ranges that have the greatest potential to penetrate the respiratory-lung system. In the event that airborne pathogenic bacteria are present (perhaps from aerolized from an infected person via coughing, sneezing) then this represents an increased infection risk. The study is on-going, and will investigate methods to reduce levels of airborne bacteria in the classroom via improved ventilation, air-exchange and/or filtration.
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Characterization of Commercial Reverse Osmosis and Nanofiltration Membranes for Membrane Fouling
Membrane Filtration technique is being accepted worldwide as an environment friendly and energy efficient technique in Desalination Industry as compared to Thermal Desalination techniques. However, the performance of membranes which include permeate flux and rejection is affected by the membrane fouling. The properties of membrane and surface features such as porous structure, hydrophilicity/hydrophobicity charge, polymer characteristics, surface roughness determine the fouling potential of the membrane. The hydrophilic and smooth membrane surface is usually considered desirable in tackling membrane fouling issues. Therefore, many studies have focused on to enhance surface characteristics of membranes by surface coating with polymers and nanomaterials. Since, membrane coating is not done during fabrication of the most commercially available membranes, therefore, it is also important to determine the surface features of the commercially available membranes to investigate their membrane fouling potential. Thus, the objectives of this study were (1) to perform membrane surface characterization of commercial Reverse Osmosis (RO) and Nanofiltration (NF) membranes using techniques such as SEM, AFM, FTIR and XPS; (2) to measure hydrophilicity/hydrophobicity of commercial RO and NF membranes through water contact angle measurement using sessile drop method and (3) to measure the flux and percentage rejection of NF and RO membranes using Dead end filtration technique. Here, the characterization of membrane surface in terms of surface roughness, using SEM and AFM, showed that the commercial RO membrane had more ridge and valley structures and higher average surface roughness i.e. 71.24 nm as compared to NF membranes (6.63 nm). In addition, water contact angle measurements showed that the NF membrane was more hydrophilic as compared to RO membrane. The average contact angle found for RO membrane was 59.94°. On the other hand, it was observed that NF membrane is extremely hydrophilic in nature. Due to which, contact angle value was not obtained for most of the runs. The droplet could diffuse in less than 5 seconds. In addition, the dead-end filtration experiments showed that the RO membrane had much lower flux as compared to NF membrane. This can be associated with the pore structure of these membranes. Since, the NF membrane has porous structure, in oppose to RO membrane, the flux of the NF membrane is usually higher than the RO membranes. As the membrane surface roughness and hydrophobicity makes it more susceptible to the fouling leading to reduction in membrane flux and performance, it can be concluded from this study that there is a need for surface coating of RO membrane with suitable nanomaterials such as graphene oxide to improve its hydrophilicity and surface smoothness. This will eventually make the membrane more resistant to membrane fouling and will establish the use of membrane filtration technique in desalination industry in Qatar in the future. Microorganisms have been isolated from Gulf sea water, identified and differentiated and are being used to study the biofouling of RO and NF membranes, that would be coated to limit the fouling problems. Acknowledgement: This research was made possible by NPRP grant # [9-318-1-064] from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the author[s].
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Reconstruction of Ribosomal RNA Genes from Metagenomic Data obtained from oilgas pipelines in Qatar
المؤلفون: Nairuz ElazzabiQatar's economic emergence is influenced in great part by its gas reservoirs. Hence, gas processing is considered as one of the major steps to aid Qatar in its transition towards a more diversified, prospered and innovative economy. However, there is a need for research to assess the quality of water in the cooling system used in the manufacture of petroleum products. Thus, assessing water quality can help complement the technologies used for gas processing and address the challenges facing gas industries. One of these problems is pipeline anaerobic iron corrosion induced by the activity of environmental microorganism. Such microbially influenced corrosion (MIC) has various technical and economic implications that have major effects on gas and oil processing. It has been suggested that the presence of sulfur-reducing bacteria (SRB) in the cooling water in oil and gas pipeline is considered as the main culprit of such corrosions due to the pipeline anoxic conditions. Thus, examining water security, which is the aversion of water-related risks, in oil and gas industry is needed. Such risks may include disrupted operations and economic losses. Thus, there is a need to improve water use efficiency in the oil industry to improve oil and gas production and the process of shipping it to different destinations. Hence, our research aims to obtain water samples from different points of the oil-gas pipelines in Qatar and carry out microbial classification. More specifically, the aim of our research is to obtain reverse transcription polymerase chain reaction (RT-PCR) sequenced DNA data using the Ion Torrent method and analyze them. First, multiple samples containing various bacterial species were obtained from different points of the oil-gas pipelines in Qatar. Then RT-PCR was carried out on these samples using specific primers that can hybridize to the conserved regions of the 16S ribosomal RNA region. The PCR amplicons were then sequenced using the Ion Torrent device. The next step is to reconstruct the 16S ribosomal RNA (rRNA) region using the computational genomics tool, SPAdes, and aim for a good coverage and a good alignment score. SPAdes is a genomic assembler that uses iterative mapping of short reads and blast them against reference sequences to reconstruct 16S rRNA genes. The reconstructed regions would be from different bacterial species and each bacteria would have its own hypervariable region that serves as a fingerprint. Hence, the reconstructed 16S ribosomal RNA (rRNA) sequences are considered reliable markers for the taxonomic classification and phylogenetic analysis of bacteria. Eventually, the data is classified and filtered using Ribosomal Database Project (RDP) classifier 2.3, which is then followed by manual extraction, categorization and evaluation. RDP is a naive Bayesian classifier that can rapidly classify bacterial 16S rRNA sequences into the new higher-order taxonomy proposed in Bergey's Taxonomic Outline of the Prokaryotes. This online classifier provides taxonomic assignments from domain to genus.Our results show that the water samples contain high percentage of the sulfur-reducing bacteria (SRB) when compared to the percentage of other microbes in the water samples. This emphasizes on the necessity to improve water security of the oil-gas cooling system by reducing the percentage of such bacteria. Hence, one of the potential future direction of this project is to identify bacteriophages that have the ability to eliminate the sulfur reducing bacteria from the cooling water system and thus reduce the chances of water contamination.
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Qatari Oil Revenue and Economic development
المؤلفون: Tabassum ParveenQatar focused on economic development since independence in 1971. The government has over the time established many developments oriented institutions and authorities, including the Supreme Planning Council, General Secretariat for Development Planning and Ministry of Development Planning and Statistics. Since the launch of QNV 2030 in 2008 with its four pillars (human development, social development, economic development and environmental development), this vision aimed to change the face of life in Qatar. Qatar is upgrading its speculation and development systems with indications of recuperation in worldwide markets in 2017. New patterns keep on emerging crosswise over esteem chain influencing supply, request and speculation situations in the nation. Both conventional players and new participants are reevaluating their arranged undertakings with updated estimates. As Qatar and worldwide markets move towards rebalancing, this article gives definite bits of knowledge into basic short and long haul factors set to shape the eventual fate of Qatar oil and gas markets. This work as a necessary manual for organizations wanting to extend and put resources into Qatar oil and gas advertises in close to medium term future. Openings and difficulties of growing new undertakings, evolving supply-request situations, development in developing markets, approach bolsters, new supplies and request sections, venture benchmarking are talked about in the exploration. For Qatar, gas costs are considerably more imperative than oil costs in light of the fact that the estimation of gas sends out surpass that of oil trades. The estimation of LNG sends out surpassed the estimation of all other hydrocarbon items in 2015, speaking to roughly 46% of aggregate ware trades. Around a fourth of Qatar»s fares of LNG is sold at spot conveyance costs, and the rest is sold as per contracts identified with oil costs (with a deferral of a half year). Concerning the dissemination of LNG sends out, in 2015, 66% were sent out to Asia, where higher costs win. Global LNG costs dropped amid the most recent a half year because of creation surplus in the area. Qatar has kept up its creation limit since 2011, however new fares from Australia and the Assembled States have started to develop. Since the vast majority of Australia»s fares goes to Asia and as Japan resumes operation of certain atomic plants, costs in Japan saw the best decay however are as yet the most noteworthy in the locale. Unrefined petroleum costs incorporating traditions charges in Japan diminished by 40.1% between November 1, 2015 and May 1, 2016. Costs related to the American Henry Center just diminished by 8.5% in a similar period. For the most part, in the US, where most gas is sold at spot costs, bring down costs win, while Japan has the most astounding costs since gas is sold by method for long haul fates related to rough costs including custom expenses. Given the abundance in delivery limit and the expected wealth in LNG supplies, Qatar is creating and restoring its showcasing strategy with a specific end goal to ensure it offers in the market, particularly supporting long haul supply assentions for LNG trades. Because of the lower allure of LNG costs and its foreseen opulence, the World Monetary Standpoint report issued by the IMF in April, 2016, tempered its desires at gaseous petrol normal costs in 2016 (the weighted normal cost in the Japanese, American and European markets), by 10.8% against a similar report»s estimate in October 2015. It is additionally conjectured value steadiness on an extensive scale in 2017 and 2018. Economy in Qatar is relied upon to stay versatile in 2017, regardless of a frustrating Gross domestic product development of 2.7% in the primary quarter (QoQ), after a 4.1% development in the last quarter of 2016. Swelling should level off in 2017. Be that as it may, costs are diminishing for lodging, amusement and eateries, which could cultivate utilization. In any case, the presentation of a uniform 5% VAT rate over all GCC nations, endorsed on May, third 2017, is relied upon to build costs subsequent to being actualized in 2018. The oil and gas segments, experiencing the fall in vitality costs, were working in the red in 2016, however they should help bolster development in 2017 with the begin of creation at the Barzan office (increment fluid gas generation by 21%). The non-oil and gas parts were dynamic in 2016, and they will keep on being, driven by development (+11.7% QoQ in the main quarter of 2017) and the administrations divisions. Development segment stays one of the main recipients of the Qatari government»s speculation arrangement for the FIFA World Container 2022. In spite of the fact that a ban has been forced on new undertakings, officially planned speculations are significant and assessed at what might as well be called nearly USD 180 billion. The administrations area (money related administrations, property and broadcast communications) should see solid development in 2017. Qatar is right now experiencing gigantic change under the rubric of the 2030 National Vision, which intends to build up a propelled, learning based, and enhanced economy, no longer dependent on the hydrocarbon area. The administration is intensely associated with Qatar»s economy, in spite of the fact that it firmly energizes private interest in numerous areas. Interests in different parts including medicinal services, instruction, tourism and money related administrations, among others,. The principle monetary boosts in Qatar are oil, gas, and related enterprises, specifically the advancement of the North Field, the biggest non-related gaseous petrol field on the planet. Qatar»s condensed flammable gas (LNG) industry has pulled in several billions of dollars in remote speculation and made Qatar the world»s biggest exporter of LNG are relied upon to offer more prominent open doors for outside venture. Qatar»s LNG conveyance cost is about $5.20/mBtu, which is near the Russian pipeline gas breakeven cost, yet $2 to $3 underneath full-cycle cost for US LNG at the present Henry Center point costs of about $3/mBtu. This implies at current costs, US LNG makers could take care of their peripheral expenses yet not long haul breakeven costs. «With its great reputation of LNG venture execution and the co-creation of condensate and LPG from the North Field, Qatar is the most minimal cost LNG maker on the planet. As of now, the seven parts concentrating on those are anticipated to have a general positive effect on the social and financial way of life in Qatar. These areas are horticulture, training, medicinal services, mechanical improvement, domesticated animals, fishery, and tourism.
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Comprehensive Assessment of Resin Systems as a Combined Solution for Well Integrity Challenge and Unwanted Fluid Shutoff in Carbonate Reservoirs
المؤلفون: Albertus RetnantoThe petroleum industry usually uses class G cement when it comes to cementing jobs. However, that was the only option before, and because of that many issues came with it. Indeed, in the Middle Eastern region as well as the rest of the world, wellbore integrity is always a reason for concern. If wellbore integrity is not guaranteed, then production or drilling operations would be done under very unsafer circumstances. In order to fix certain leaks or cracks found in the well, resin cement can be used in order to prevent any interaction between the wellbore fluids and the formation fluids. Because of its elasticity and high compressive strenght resistance, the resin will fill in the fracture or space perfectly and seal it off thus preventing any future issues. An example of that would be when they used resin cement in the Utica shale formations where annular pressure buildup was faced due to a fracture found in the casing. The pressure buildup disappeared completely after they had applied resin cement into the fracture. It was also used to solve a combo problem when the operator was producing from Polish shale. Indeed, the problem was that they wanted to fracture the formation in order to improve productivity, however by fracking the formation, they would also damage the well and put the well into danger. In order to preserve wellbore integrity, the parts in the well were repaired by injecting resin cement in areas where the casing wasn>t well cemented. The operator company was the able to frac the formation with no wellbore integrity. Similarly, resin cement can also be used to abandon a well. Indeed, in order to perform a good abandonment, one major aspect that is focused on is that not pressure is bled off from the well. However, when gas is present, it sometimes keeps leaking despite the cement there. Which is where resin cement comes in hand. Because of its unique properties, the resin cement will be able to seal off the well completely with no issues due to its elasticity and how it sets. Other than resin cement being great to use as a seal, it also has a very high compressive and tensile strength compared to normal class G cement.We had to run several different tests to look at the different aspects it withheld. Thus, the resin was put through (transit time testing, temperature, compressive strength, acoustic impedance, and finally a crush test). To undergo all these tests there was a process that had to be followed so that all of our results were under API standard and were obtained in a safe manner.This research is aimed at seiing how resin cement as well as the mix of resin with class G cement can improve well integrity as well as combined solution for unwanted fluid shut-off in the Middle Eastern region, i.e. for carbonates reservoir and under typical reservoir temperatures and pressures found in this region. Through these results, we will be able to assess the application that can be used for any remedial jobs no matter what the issue and how great of a seal it can be. All of this will be seen through its enhanced properties.
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Novel Control Algorithm for control of qZSI as Front – End Converter during nonsunlight hours
المؤلفون: Rahman Syed, Meraj Mohammad, Iqbal Atif and Haitham Abu-RubDegrading effect of energy generation from fossil fuel are extensively discussed and debated leading to paradigm shift to renewable energy generation. Energy generation from PV panels is the best alternative for state of Qatar which gets abundant sunlight throughout the year. Development of energy generation from PV panels helps in achieving the notion of “Energy Security”. Energy security refers to availability of reliable, cheap and quality power for consumption from customer point of view. Development in power electronics helps in achieving this idea by developing and operating converters circuits with good efficiency, efficacy, reliable, robust and free from maintenance. Encouraging the nurture and development of local energy suppliers will help in minimizing the cost of installation and maintenance. Including these economic constraints in the design of converters has become a crucial factor in developing industry oriented products through academic research. Suitability of several power converters for synchronizing the power generated from PV panels to utility grid. Recently developed Impedance source based converters are highly suitable for synchronizing the power generated from renewable energy to the utility grid. They eliminate the need for extra dc-dc converter by boosting the input voltage supplied from PV panels. Impedance source based converters are categorized as: Z Source Inverter and quasi Z Source Inverter (qZSI). qZSI is preferred due to its higher performance and continuous input current. Several methods are discussed in the literature to achieve boosting of input voltage. Inverter control requires modification in conventional Sine-Triangle compared based PWM. Operation of qZSI at different MPPT algorithms is also discussed. Cascaded qZSI operation to achieve higher power rating are also discussed. Implementation of advanced control techniques such as Model predictive control is also presented. Energy efficient qZSI achieved through different methods are also discussed. This paper presents novel control algorithm for control of qZSI as Front-End Converter (FEC) during non-sunshine hours. During sunshine hours, qZSI is controlled to inject active and reactive power into the grid. In absence of sunlight, qZSI can be operated as FEC to control reactive power management with the utility grid. To validate the proposed control algorithm, simulation results are presented for grid-connected qZSI powered from solar panel as shown in Fig. 1. Simulation results are formulated into following three sections: (a) Control of qZSI for active and reactive power management, (b) Transient response for qZSI to FEC transition and (c) Control of FEC for reactive power management.Control Algorithm: Control algorithm must satisfy the following requirements: a) When controlled as qZSI, i) Boosting of input voltage must be controlled to achieve the desired output rms voltage ii) Current injected into the grid can be at any power factor – unity, lagging or leading. b) Smooth transition from qZSI to FEC. c) When operated as FEC, i) DC Bus Voltage must be maintained constant and ii) Controlled reactive power management must be achieved. Proposed control algorithm is as shown in Fig. 2. It consists of two types of control blocks. Control blocks which are specific to a type of control algorithm and other which are common for both. Converter reference voltage generation and conventional Sine – Triangle comparison is common to control algorithms of both the inverters. For control of the inverter as qZSI, condition of Vin>Vth must be satisfied which means voltage generated from PV panels is sufficient for grid synchronization. During this mode, S1 and S3 are closed and S2 is opened. qZSI control consists of grid current control and dc bus voltage (Vdc) control. Active and reactive power demand is converted to current proportional and passed through PI controller to generate the converter voltage reference. DC Bus voltage controller gives the shoot-through duty cycle (D). Based on the value of D, shoot-through pulses are ORed with conventional pulses generated by sine-triangle comparison. When Vin>Vth is not satisfied, then the position of relays is changed. S1 and S3 are opened and S2 is closed. Due to this, the solar panel is disconnected from the inverter. The dc bus formed due to series connection of C1 and C2 must be controlled from the grid voltage. The dedicated control block shown in Fig. 2 for FEC generates the active current reference and add it up with required reactive current reference to give the grid current reference. This is passed through PI Controller to give the converter voltage reference. Conventional Sine-triangle comparison is performed to generate switching pulses.SIMULATION RESULTS To verify the control algorithm, the simulation results are shown in Fig. 3. Up to t = 2 sec, the inverter is operated as qZSI injecting controlled active power into the grid. At t = 2 sec, the relays are operated disconnecting the solar panel at the input and now inverter is controlled as FEC. Due to this, the dc bus voltage shoots up which is controlled with the control algorithm. To maintain the dc bus voltage, active current is drawn from the grid. Active current drawn is negligible compared to reactive power managed with the utility grid. Figure 3(a) shows the response of dc bus tracking during the operation. In qZSI mode, active power injection is controlled as shown in Fig. 3(b) and Fig. 3(c). When the inverter is controlled as FEC, reactive power absorbed and supplied are shown in Fig. 3(d) and Fig. 3(e) respectively.
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Energy Metabolism Analysis in Qatar From Socioeconomic Dimensions
المؤلفون: Sami G. Al-GHamdi and Abdulrahman AL-TamimiDue to rapid urban development and increasing population, urban areas are facing more challenges in the area of sustainable development. In order to make sure that these cities are moving toward sustainable development, it is very important to highlight the human activities as significant elements in terms of energy metabolism. This paper employed the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach to analyze the energy metabolic pattern of Qatar from ecological, social, and economic dimensions. MuSIASEM has been introduced for the first time late 90’s, and it is trying to answer the questions of how and why humans use resources? how this use depends on and affects the stability of the ecosystems embedding the society? Therefore, this study aimed to track and record level of energy sustainability in Qatar, describe and analyze the energy and GDP flow in Qatar using MuSIASEM. Energy consumption per capita in Qatar reached 17,418 kg of oil equivalent in 2014, while the rate in US is 6793 kg of oil equivalent. That makes Qatar one of the biggest energy consumer around the world, and that's has negative impacts on our society e.g., CO2 emissions per Capita in Qatar reached 37.78 metric tons in 2013. A case study of Qatar was considered instead of the capital and largest city (Doha) because all the urban areas and human activities in Qatar are connected with Doha, especially with the small area of Qatar 11,627 km2. Thus, Qatar is the suitable study's area compared with the mega cities around the world. In addition, all the previous studies which used MuSIASEM as methodology focused on countries which import energy, but Qatar exports and produces energy, and that makes the study unique and valuable. The study investigated historical pattern changes of human activities in Qatar with focusing on working hours in line with Gross Domestic Product, then evaluated the possible results, so that the detailed metabolic patterns can be identified and appropriate development policies can be prepared to help decision makers with the implementation of Qatar Vision 2030 which consider sustainable development as fundamental pillar. The results investigated the correlation and interactions between Gross Domestic Product, added value, human activities, energy consumption, energy intensity, exosmotic energy metabolism, and future economic transition in Qatar. To make the results systematic and organized, it have been subdivided hierarchy into three levels: Level n studied The whole society of Qatar, Level n-1 studied both of consumptive sector (hose hold) and productive sector (work sector), Level n-2 focused on the subdivisions of work sectors and house hold typologies. Speaking of data resources, the economic and social data of study have been provided by Ministry of Statistics and Development Planning, While the electrical data has been provided by Qatar General Electricity and Water Corporation (KAHRAMA). World Bank, and International Energy Agency (IEA) provided all the date related to energy consumption. Other data like human time, energy intensity, and exosmotic metabolic rate have been calculated through some equations which will be explained in the study.
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Detailed exergy analysis of full scale LNG plant
المؤلفون: Essa Al-Musleh, Mohamed Hussein, Mary Katebah and Zineb BouabidiSustainability is one of the major challenges faced by the industrial sector as it is driven by both environmental and economic factors. Energy demands are increasing and, to date, most of the supply is generated via fossil-fuel combustion, such as coal, gas or oil. However, these processes release greenhouse gases, mainly CO2, that contribute to global warming and other environmental issues. Of the three fossil fuels, for a given amount of energy released, natural gas produces the least amount of CO2, making it the most vital energy source. The most practical way of transporting this natural gas over long distances is via liquefaction. However liquefied natural gas (LNG) plants consume substantial amounts of energy; thus, releasing significant amount of CO2. Therefore, enhancing the efficiencies of LNG plants is essential especially for large producer such as Qatar. As of today, Qatar is the largest producer of LNG in the world, with a capacity of near 78 Million tons per annual (MTA). Since the LNG industry in Qatar is a major contributor to the country's economy and development, there is a continuous need to improve and optimize existing LNG systems to extract more value out of them. Optimization of such complex system is; however, not a straight forward technique requiring different expertise ranging from engineering/process oriented insights to mathematical and thermodynamics techniques. Thus, it is deemed essential to identify plant sections that must be given priorities for optimization. This requires quantifying losses and efficiencies and one of the effective tools is exergy analysis. Identifying the areas of exergy losses within LNG plants emphasizes the areas where optimization is necessary. This project aims to foster the transition to cleaner LNG plants that operate more efficiently, in terms of energy consumption, towards an active contribution to the protection of the environment. The primary focus of the study is to identify exergy losses across a baseload LNG plant producing more than 3 MTA of LNG. In this research, a rigorous and detailed exergy analysis was performed on an entire actual LNG process that was simulated using ProMax® and Aspen Plus® simulation software. In order to carry out the thermodynamic analysis, exergy loss across each component of the entire plant was determined. Exergy analysis was not limited to process units, as it was extended to quantify exergy loss across the utility section. Results revealed that the main contributors to the exergy loss are the utility section, accounting for 49% of the total exergy loss. Within the LNG process, significant amounts of losses were found to occur in the liquefaction, sweetening and sulfur recovery units; corresponding for 37%, 30% and 21% of the total exergy loss, respectively. Components responsible for the highest exergy consumption were also highlighted, with the main consumers being the compressors and their drivers, stream generators, LNG flashing and storage, columns (absorbers, distillations) and heat exchangers. The contribution to the total exergy loss provided some insight on locations where improvements are needed to translate into more environmental and energy benefits. For example, most of the losses within the liquefaction section was attributed to compressors and the drivers responsible for the generation of the required shaft work; almost 19 MW exergy loss in the gas turbine corresponds to 1 MW exergy loss in the associated compressor. Thus, significant energy savings can be achieved via minimizing the compression energy. *Corresponding author. +974 44034148 Eamil address: [email protected] (E. Al-musleh) References [1] «2016 World LNG Report - International Gas Union,» Chevron, USA2016, Available: www.igu.org/download/file/fid/2123.
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Designing piezoelectric nanogenerator from PVDFHFP nanocomposite fibers containing cellulose nanocrystals and Fedoped ZnO
المؤلفون: Deepalekshmi Ponnamma, Hemalatha Parangusan, Aisha Tanvir and Mariam Al Ali AlMaadeedSelf-powering devices harvest energy from the environment and perform based on a maintenance free approach. These materials are of utmost significance as they solve the problems associated with the energy crisis and management, to greater extends. Advances in material science and the design of various polymer nanocomposites developed many self-powering devices that are flexible, sensitive, less power consuming and of low cost. The semi-crystalline polymer, poly vinylidene fluoride (PVDF) and its co-polymers are notable for mechanical energy harvesting because of the typical crystalline phases in their structure. Various nanoparticles are added to such polymers to enhance their dielectric and piezoelectric properties as well. Since the alignment of crystalline phases improve the energy harvesting properties, techniques such as electrical poling are practiced to enhance their applicability. Among various alignment procedures, electrospinning stands as unique since the high voltage applied to the polymer solution generates nanofiber scaffolds in perfect alignments. The present work aims to develop electrospun composite fibers in nano-dimensions for designing self-powering nanogenerators. The co-polymer of PVDF, polyvinylidene fluoride hexa fluoropropylene (PVDF-HFP) was used as the base polymer and the iron-doped zinc oxide (Fe-ZnO) and cellulose nanocrystals (CNC) as the filler reinforcements. Fe-ZnO nanostructures were obtained by hydrothermal synthesis method from the ZnO precursor, while the CNC were synthesized following the acid hydrolysis of cellulose microfibers. The optimized concentration of 20 wt.% was used for obtaining the electrospun fibers of neat PVDF-HFP and various concentrations of nanoparticles were mixed with this base solution. Simple solvent mixing was employed using the acetone/DMF solvent mixture to prepare the composite solutions prior to electrospinning. The electrospinning conditions were also optimized by varying the applied voltage, tip to collector distance and speed of the rotating collector. Nice fibers were obtained at a voltage of 12-13 eV and rotating collector speed of 200 rpm. Composites of CNC with PVDF-HFP, Fe-ZnO with PVDF-HFP and the hybrid material of CNC/Fe-ZnO with PVDF-HFP were prepared and properties were investigated. All the fibers were tested for the morphology, structural, thermal and dielectric properties. The mechanical energy harvesting was performed using an assembled set up containing a frequency generator, shaker and data acquisition system. At 2 wt. % of the nanofillers, the PVDF-HFP/CNC generated about 2 V, the PVDF-HFP/Fe-ZnO generated about 4 V and the hybrid nanocomposite containing both nanoparticles generated about 6 V. The filler synergy plays a major role in regulating the material properties and here the combined effect of the piezoelectric performance of the cellulose nanocrystals and the modified ZnO nanoparticles enhanced the mechanical energy harvesting capability of the final nanocomposite. A nanogenerator is designed based on the developed polymer nanocomposite fibers and the piezoelectric performance on various conditions of stretching, pressing and twisting were also investigated. In all the cases the hybrid composite showed notable performance substantiating its application in designing self-powered nanogenerators. The dielectric properties of the hybrid material showed many fold increase in its dielectric constant, making it useful in electrical energy storage. In short, the designed device by electrospinning technique is highly useful in adding to the energy management and is environmentally safe and of good efficiency.
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Low cost anode electrocatalyst for Direct Methanol Fuel Cell applications
المؤلفون: Syed Javaid Zaidi, Sajeda Adnan Mutlaq Alsaydeh and Ammar Bin YousafDirect methanol fuel cell has attracted worldwide attention as a promising alternative clean energy source due to growing environmental problems. A number of scientific groups are working to develop the fuel cells and make it a viable clean energy option. For fuel cells to be a feasible and economic viable innovation in the materials development, such as new electrocatalyst and polymer electrolyte membranes are required. Significant advancements in materials developments are required for fuel cells to be feasible for a wide range of portable, automotive and stationary applications. For DMFC, there are some challenges that need to be addressed before this technology become competitive, for example- slow kinetics of methanol oxidation, high methanol permeation resulting drop in fuel cell performance and the high cost of the catalyst. In the present work we focus on the electrocatalyst materials development for methanol electro-oxidation on the anode surface of DMFC. Platinum (Pt) and/or copper (Cu) based multi composition low cost electro-catalyst have been synthesized and characterized by impregnating onto the carbon nano-tubes (CNT) composites. These nanocomposite electrocatalyst materials have been characterized for their morphology by scanning electron microscopy (SEM), structure by X-Ray Diffraction (XRD), element mapping and other chemical and thermal properties by Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA), and X-ray Photoelectron Spectroscopy (XPS). The results of the characterization confirmed successful formation of the desired electrocatalyst material. The electrochemical activity of these electro-catalysts for methanol electro-oxidation have been studied by cyclic voltametry (CV) and chronoamperometery (CA) at various concentrations of methanol and current density. The characterization and electrochemical activity tests showed good performance for the electro-oxidation of methanol for DMFCs. The present study opened up new avenues for developing lower cost Pt-based catalysts with better performance. These nanomaterials have potential to be used as electrocatalyst for DMFC applications. Keywords: Electrocatalyst, nanocomposite;direct methanol fuel cells, electro-oxidation. Acknowledgements: This publication was supported by Qatar university Internal Grant No. QUUG-CAM-15\16-2. The findings achieved herein are solely the responsibility of the author[s].
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