Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1

Plastic electronics has made great commercial and scientific progress over the past decade, predominantly driven by the potential of applications such as organic field effect transistors (OFETs) for flexible backplanes and e-paper, organic light emitting diodes (OLEDs) for large area lighting and displays and organic solar cells (OPV) for large area energy generation.1,2 Much of this work has been motivated by the fact that organic semiconductors can combine the superb mechanical and processing characteristics of plastics with a variety of printing techniques, enabling large-area, low-cost manufacturing. There has been an intensive worldwide research effort on the development of stable, conjugated organic semiconducting polymers as potential replacements for conventional silicon, the benchmark large area amorphous semiconductor. ID TechEx, the UK-based market research company, “estimates that over the last two decades global investments into plastic electronics technologies exceed US $10 billion, and predict that this will grow to almost US $25 billion by 2020”.3 The ecological and commercial motivation to implement the use of plastic electronics is compelling. Recently, such efforts have facilitated the development of thin film transistors for backplane applications such as e-paper. The ability to operate in ambient atmosphere without costly and rigorous encapsulation barriers to avoid water and/or oxygen is an important step towards commercialization. Research for cleaner alternatives of energy generation and advanced energy permitting devices has journeyed down an interesting path. The exploration of conjugated organic materials within the context of energy has led to the development of devices with great potential for utilization and exploitation within the near future, where perhaps the emergence of hybrid materials or the utilization of nano-architectonics will be of paramount importance to aid in the development of state of the art nanotechnology and its utilization within energy related themes. Meanwhile, further reducing of the cost is expected in the next decade as a result of designing next generation of energy devices (e.g. supercapacitors, solar cells, Li-ion batteries, fuel cells). Organic PV active layers (especially polymer based materials) have the latent potential of solution based processing of the active layers, offering the attraction of low-cost, continuous roll-to-roll or printing processing of large area devices upon flexible substrates. These deposition techniques of the active layers may allow devices to meet the $15/m² target; for comparison paint costs about $1/m². Furthermore, organic active layers offer infinite design space by virtue of the polymer architectures, providing potential for layers design and tunability to suit specific energy supply criteria.4 The development of more efficient energy-producing devices and cleaner energy generation alternatives continue to advance. The investigation of polymeric materials within the context of solar energy has thus far yielded devices with great potential. Through systematic chemical modification, the performance of OPV cells has advanced impressively over the last three years, with power conversion efficiency (PCE) now routinely surpassing 8%, and attracting industrial interest in commercializing this technology.5 The synthesis of well-defined conjugated molecules/polymers is a considerable synthetic challenge that many excellent research groups have addressed over the last decade or so. A particularly promising class of potential donor/acceptor materials for use in BHJ solar cells and organic electronics are the aromatic donor-acceptor amido pigments diketopyrrolopyrrole (DPP) and isoindigo and the electron deficient bis-Thiazole (Figure 1). Here, an electron-rich aromatic segment is positioned adjacent to a highly electron-deficient amide link typically known as a push-pull chromophore.6 When incorporated into small molecules or polymers, this structure affords very narrow band-gaps capable of harvesting a large percentage of the solar flux. Both DPP and isoindigo units have recently been used to construct some of the most efficient organic solar cells to date, and the present work capitalizes on these advances, and goes beyond. Figure 1- Chemical structures of DPP, Isoindigo and bis-thiazole. Here we will present our synthetic efforts on developing the novel polymeric materials containing the three structures shown in Figure 1, particular emphasis on a suit of carefully selected sidechains, which has provide access to a wide range of monomers with tuneable solubility (with either short or long, branched or linear alkyl chains). Moreover, the initial synthetic targets will specifically be the introduction of branched ocytyl-decyl chains as well as linear hexadecyl alkyl chains since they have both been used in other high efficiency conjugated polymers-the latter are known to enhance interchain interdigitation and close π-π stacking.

References: (1) Kim, Y.; Cook, S.; Tuladhar, S. M.; Choulis, S. A.; Nelson, J.; Durrant, J. R.; Bradley, D. D. C.; Giles, M.; Mcculloch, I.; Ha, C. S.; Ree, M. Nat Mater 2006, 5, 197.

(2) Chen, H. Y.; Hou, J. H.; Zhang, S. Q.; Liang, Y. Y.; Yang, G. W.; Yang, Y.; Yu, L. P.; Wu, Y.; Li, G. Nat Photonics 2009, 3, 649.

(3) http://ukplaticelectronics.com, C. G.-U. P. E.

(4) Krebs, F. C.; Gevorgyan, S. A.; Alstrup, J., J. Mater. Chem. 2009, 19 (30), 5442–5451.

(5) Guo, X.; Zhou, N.; Lou, S. J.; Smith, J.; Tice, D. B.; Hennek, J. W.; Ortiz, R. P.; Navarrete, J. T. L.; Li, S.; Strzalka, J.; Chen, L. X.; Chang, R. P. H.; Facchetti, A.; Marks, T. J., Nat. Photon 2013, 7 (10), 825–833.

(6) Li, Y.; Sonar, P.; Murphy, L.; Hong, W., Energy Environ. Sci. 2013, 6 (6), 1684–1710.

(7) Cates, N. C.; Gysel, R.; Beiley, Z.; Miller, C. E.; Toney, M. F.; Heeney, M.; McCulloch, I.; McGehee, M. D., Nano Lett. 2009, 9 (12), 4153–4157.

The implementation of large-scale renewable energy systems (such as solar and wind) in the GCC is widely growing nowadays, particularly in remote areas generation applications where the grid extension is costly. The integration of renewable energy systems into the existing power grids, especially the hybrid ones like hybrid solar wind systems, not only provide a clean environmentally friendly supply of electricity but also provide a more reliable supply of electricity through the utilization of different energy sources. However, the operating characteristics of such renewable energy systems are strongly influenced by the weather patterns, i.e. intermittent generation, and will therefore impact the operation of the power grid into which they are integrated. Certain amounts of renewable distributed generation can be integrated into the existing grid without affecting its operation; however, the massive introduction of large-scale renewable energy systems into the grid will result into an increased level of risk of overload and over voltage, unacceptable levels of power quality and reliability, together with the possibility of incorrect operation of the protection system. Therefore, significant investments will be needed to enable the existing power grids to accommodate such a large scale of renewable energy systems into it while avoiding such impacts.In this paper, a comprehensive study of the impact of integrating large-scale hybrid renewable energy systems into Qatar's electrical power grid is carried out. The study includes investigating the grid power flow, power quality, efficiency, transient stability, and reliability under both normal and contingency operating conditions. The study aims to give solutions for allowing the increase in large scale hybrid renewable energy systems penetration into Qatar's grid while reducing their influence and maintaining the grid reliability and stability during all operating conditions. The study is performed based on Qatar's grid real-time operating conditions, and takes into account Qatar's climate profile (e.g. Qatar average annual wind speed and solar irradiation) in order to simulate the intermittent output of the integrated hybrid renewable energy system. Moreover, an economic study and an environmental impact study are carried out to evaluate the large-scale integration of hybrid renewable energy systems into Qatar's grid from different aspects. In summary, the carried out studies will show the impact of implementing large-scale hybrid renewable energy systems on the performance of Qatar's power grid, together with its environmental and economic benefits. The real-time implementation will suggest how to introduce the large scale hybrid renewable energy systems gradually into Qatar's grid, and will propose the best scenario for operating both the existing conventional stations and the integrated hybrid systems while balancing their electricity generation with the demand. The real-time implementation utilizes a new smart control and management mechanism that is proposed to allow such a balance between the generation and demand on introducing large-scale hybrid renewable energy systems into Qatar's existing power grid. The outcome of this study will help Qatar in assessing and evaluating the operational, environmental and economic aspects of large scale hybrid renewable energy systems penetration into Qatar's power grid, and will demonstrate the challenges that will face Qatar when integrating such a large capacity into its grid.

Hybrid desalination (thermal/membrane) process is a viable solution in Gulf Cooperation countries (GCC). In GCC, large thermal desalination plant, e.g. Multi Stage Flash (MSF) and Multi-Effect-Distillation (MED), exist and will stay in operation through their expected life, (10’s of years) while new large capacity reverse osmosis (RO) plants should be applied to lower the water specific consumed energy and cost. The thermal desalination technology was the prevailing technology in the GCC, where capacity per unit is large (up tom 20 MIGD), low energy cost was assumed, seawater salinity is high, and combining desalting plants with power plants provides low cost steam extracted from turbines to desalting plants at low pressures (e.g. 1–3 bars). However, in recent years, membrane systems, namely seawater reverse osmosis (SWRO), become the prevalent desalting worldwide as a result of much lower specific energy consumption (compared to MSF and MED systems), development in RO membranes properties and energy recovery devices, and low electric load in winter forcing some power plant units to cease operation, and thus unavailability of steam extracted from turbines. In this case, the boiler generated steam is wastefully throttled to the conditions required by desalting units. Realizing the fact that large MSF and MED are existing and operating, while large SWRO have to be implemented, combining the operation of both technologies can be beneficial and a need to have optimum configurations exist in terms of reduced total desalted water cost. The synergy of the present commercial hybrid thermal/membrane desalting plants is limited by using common intakes and outfalls facilities, while are running independently at the same site. Product water of both membrane and thermal plants are usually blended to meet the international standards water quality specifications.

Moreover, the use of forward osmosis (FO) as a pre-treatment to the MSF units was suggested to remove the divalent ions, such as MgSO4 and CaSO4 in order to increase the top brine temperature (TBT) beyond 110°C was suggested. This increases the MSF unit capacity and gain ratio. In this arrangement, the MSF brine (of high concentration) is used as draw solution to the incoming seawater to the FO membrane. The brine is diluted by drawing pure water from seawater feed, and is circulated back to the MSF unit where distillate is recovered. The main advantage of this suggestion is the use of brine as draw solution without the need to external solution and the MSF process is utilized as recovery process. However, the relatively low osmotic pressure of the brines necessitates high required FO membrane area, which is expensive.

In the present work, a new configuration of tri RO-FO-MSF hybrid desalination process is proposed. The aim of the proposed configuration is reduce the specific thermal energy consumption by producing the desalted seawater by both MSF and RO systems. The cooling water leaving the MSF heat rejection sections is used as a feed to RO to improve the RO productivity (i.e. recovery ratio). The RO brine and MSF blow-down mixture is used a draw solution to the FO process, and the diluted solution is directed to the MSF unit. This lead to higher productivity and low chemical consumptions compared to separate systems.

A flexible and powerful tool of Visual Design and Simulation program (VDS) is used to evaluate this novel tri hybrid RO-FO-MSF. Typical desalting plants are simulated to verify and the wide scope and high capability of the developed package. In this work, the scope of the VDS program is extended to develop novel tri hybrid RO-FO-MSF and compare it against MSF-NF, MSF-FO and RO-MSF configurations. In order to compare among different configuration, the reference RO plant (33 MIGD) in UAE and reference MSF (15 MIGD) unit in Qatar are considered as a base of comparison.

For fare comparison between thermal and membrane in terms of energy consumption, the equivalent mechanical energy of thermal energy associated with heating steam supplied to the brine heater of the MSF is calculated using exergy method. This equivalent energy is equal to the power loss in steam power plant due to combined with thermal desalination plant. The equivalent energy varies according the Gain Output ratio (GOR) of the thermal system. The total energy consumption in MSF unit is a summation of the equivalent of the thermal energy and pumping energy.

Comparison between different hybrid configurations will be based on total consumed energy per unit production at different recovery ratio of the system. In the present methodology, a fixed value of input seawater feed flow rate is specified and then total energy consumption is calculated at varying recovery ratio for each hybrid system.

Simulation results showed that the consumed energy of the hybrid FO-MSF is 10 % lower than NF-MSF and 29 % higher in the recovery ratio. The hybrid RO-MSF in series is 20 % higher in the recovery ratio and 60 % lower in consumed energy compared to the traditional MSF. The hybrid RO-MSF consumes the same energy of standalone RO however the recovery ratio is 23 % higher than RO.

The recovery ratio for tri-hybrid RO-FO-MSF configuration is higher 30 % higher, when compare with the traditional MSF and standalone RO. The consumed specific energy in the tri hybrid configuration is 60 % lower than MSF and consume the same energy of the RO process.

The tri hybrid RO-FO-MSF, when compared with other hybrid configurations, has superior lower consumed energy, as well as with standalone MSF and RO processes. The novel

(RO-FO-MSF) configuration provides a solution of the limited recovery ratio of the standalone RO and MSF.

The product blend of the MSF distillate and RO permeate would enable using single pass RO and excluding the second pass which will reduce the capital investment cost. Also the product blend will resolve the borne issue rose up in standalone RO plant since the permeate of the RO is diluted by the MSF distillate.

The date palm tree produces a highly nutrition fruit in harsh environments found in a region stretching from North Africa, through the Arabian Gulf to India. The ability to withstand high temperatures, high salinity water and other environmental challenges makes the date palm an excellent candidate for food security in this region of the world. In 2011 we published the first date palm genome sequence in Nature Biotechnology (Al-Dous et al. 2011). Based on this ground-breaking work we proposed to establish both the infrastructure and research to allow Qatar to lead in the biotechnological development of the date palm tree. This proposal was recently supported by QNRF who awarded the first exceptional award for date palm research.

Here we show our findings from both the research and infrastructure development. This includes the establishment of the first date palm biobank, genome sequencing of multiple date palm trees from across the world, identification of candidate genes for gender determination, fruit length and fruit color among others. The results of the research will provide opportunities for development and commercialization in Qatar and the rest of the region as emphasis is put on changing environments and the need for food security. To establish the infrastructure for this research we have utilized expertise and pipelines developed in Qatar to analyze multiple date palm ‘omics data. Our approach is based on the combined expertise in next-generation DNA sequencing, Single Molecule Sequencing, Metabolomics, Bioinformatics and Phenotype analysis. These are then combined with expertise in local date palm orchards to look at the possibility of translating findings to the farmers.

Our major outcome is the date palm genome and its metabolic characterization as its read out. To obtain the most detailed results we created the first date palm biobank with over 250 date fruit types collected from across date palm cultivating countries. Phenotype and genotype information has been collected on these fruit. Candidate markers related to date palm gender, flowering time, fruit color and size have been identified and are currently being developed further. To translate our research to agricultural application we have worked with Ministry of Environments Biotechnology Centre to understand how various fertilizers affect the microbiomes surrounding date palm trees and ultimately their fruit yield. Additional ongoing projects with Qatar University seek to identify the optimal date palm male pollinators to improve date palm fruit yield.

To understand the relationship of the date palm to Qatars Environmental sustainability we have conducted a survey of date palm genetic diversity across the municipalities of Qatar. Multiple leaf samples were collected from each municipality and genotyping was conducted on all DNA including date palm and any potential pathogens. This study has identified the main types of trees growing across Qatar as well as the main associated potential fungal and microbial pathogens.

The project has resulted in multiple intellectual property disclosures and partners for the commercialization of these are actively being pursued.

This work was conducted by the Date Palm EP group and funded by a grant from Qatar Foundation National Research Priorities, NPRPX-014-4-001 Link: http://dactylifera.org

There has been a tremendous proliferation in plastic production in the last five decades due to its low cost and versatile applications. Plastic debris dominates the marine litter globally and has been found in the most pristine environment including the abysmal region of the world ocean. Studies show that over 8 million tons of plastics are dumped in the ocean annually (Gregory, 2009). Plastics are persistent in the environment and take several decades to degrade especially in the ocean. Large plastic debris can heavily damage the coral reefs and may cause entanglement, choking, blockage of digestive tracts when ingested by turtles, whales, sharks etc, causing several thousand deaths annually among these organisms. Microplastics are tiny plastic particles that seldom originate from fragmentation of large plastic debris or are produced to serve some specific purposes. Microplastics pose greater threats as they can be mistaken for food by filter-feeders and planktivorous fish, and can also adsorb large quantities of recalcitrant organic pollutants (OPs). Impacts on marine biota may include endocrine disruption, carcinogenesis, and sexual disruption, etc. These impacts may not always be obvious but OPs surely affect marine biota once they enter the food web even at low concentrations (Mato et al., 2001) which biomagnify up the marine food web, hence, explains the need for their investigation.

In this study, the spatial and temporal distribution of microplastics was investigated for the first time in Qatar; both in sediments and seawater. Eight beaches across Qatar and four sea surface stations were surveyed between the months of December 2014 and March 2015. The objectives of this study were:

1. To analyze the spatial and temporal variability of microplastics in seawater and sediments, in sea surface and intertidal sandy beach environments, respectively.

2. To characterize the isolated microplastics based on size, shape, colour, and type of polymer.

3. To describe macroplastics collected from beaches based on polymer type and quantify the concentration of OPs adsorbed on their surfaces.

4. To investigate the rate of adsorption of OPs on virgin plastic pellets in a field experiment.

A general overview of the followed methodologies is given in Appendix 1. In the first phase of this study, the spatial and temporal distribution of microplastics was investigated in seawater and sediments respectively. Four sea surface stations (Appendix 2) and eight beaches (Appendix 3) across Qatar were surveyed between the months of December 2014 and March 2015.

Seawater was sampled respectively with a surface neuston net (300 μm mesh size) towed off the side of the speedboat in undisturbed water for 5 minutes at 1.5 knots (Doyle et al., 2011). Next, collected materials in the cod were transferred into labeled, acid-treated insulated glass containers to prevent contamination. Concentrations of microplastics were given in square meters as sampling was done in two-dimensional air-sea interface. Physicochemical parameters (temperature, salinity, pH and dissolved oxygen) were measured in-situ and recorded at each sampling site.

Additionally, eight coastal stations (Al Dhakhira, Ras-Laffan, The Pearl, Doha Bay, Al Ruwais, Dukhan, Umm Bab, and Mesaieed) were chosen on the basis of their accessibility and being evenly distributed along Qatar coastline.

For each sampling, sediments from the top 2 cm were collected at the most recent high tidal mark on shore from a square area (0.5 ×  0.5 m) along the shore line. Three replicate quadrats (5 meters apart) were sampled in each beach. The samples were homogenized and transferred into acid-treated glass containers to prevent contamination and transported to the laboratory for analyses.

Microplastics (Appendix 4) were discovered in all samples and their abundance varied both in intertidal sandy beaches and sea surface. Two-factor ANOVA revealed that the spatial variability of microplastics in sea surface stations was statistically significant however, there was no observable temporal variability (Appendix 5). The average concentration of microplastics in all 8 beaches was not significantly different (Appendix 6). Chemical analysis revealed the occurrence of OPs with endocrine effects on all obtained macroplastics, and concentration of pollutants was consistent in all sites. Large piece-to-piece variations of contamination up to two orders of magnitude were discovered within sites (2 to 1,005 ng/g), although there was no significant difference in contaminant concentration among all sites for PCBs and PAHs respectively.

Since plastic debris are hydrophobic and easily adsorb organic pollutants the second phase of this study was targeted at investigating the concentration of PCBs and PAHs adsorbed on macroplastics in situ. Field adsorption/desorption experiment was performed to investigate how pellets of different polymers and contaminated with POPs behave when placed in ambient seawater. Pellets were deployed and later retrieved at 48h, 96 h, 192 h, and 312 h respectively. The pellets were analyzed for PCBs and PAHs and undeployed pellets were also analyzed at time 0. Adsorbed PCBs and PAHs concentration showed a steady decrease with time, suggesting that contaminated pellets ending in the marine environment release their adsorbed contaminants in less contaminated seawaters revealing a complex OPs dynamic between plastics an seawater as a function of differential concentrations of pollutants and environmental conditions.

This study is the first of its kind in Qatar and seemingly in the entire Arabian Gulf region. Marine pollution is a growing concern in Qatar coastal and offshore environment. Marine debris is of major concern due to the fact that plastic can take several decades to be fully degraded. Results from this study indicate that microplastics are ubiquitous in Qatar coastal environment and the fact that they are easily mistaken for food and ingested by zooplankton and smaller fishes makes them a serious threat to the marine food web. Hence, regular monitoring of the occurrence of microplastics and studying how they may affect the foodweb and potential contaminations of exploited (seafood) species are needed to give policy makers an insight of the sources of the debris and proffer suggestions on how to tackle the menace using a holistic approach.

References

Doyle, M.J., Watson, W., Bowlin, N.M., Sheavly, S.B., 2011. Plastic particles in coastal pelagic ecosystems of the Northeast Pacific ocean. Marine Environmental Research 71, 41–52.

Gregory, M.R., 2009. Environmental implications of plastic debris in marine settings: entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Philosophical Transactions of the Royal Society B: Biological Sciences 364, 2013–2025.

Mato, Y., Isobe, T., Takada, H., Kanehiro, H., Ohtake, C. and Kaminuma, T. 2001. Plastic Resin Pellets as a Transport Medium for Toxic Chemicals in the Marine Environment. Environmental Science & Technology 35 (2), 318–324.

Recent evidence suggests that some densely populated areas of the world will be uninhabitable in the coming century due to extreme climate events (e.g. heat waves, atmospheric pollution, and drought) and due to shifts in microclimate and breathable air, which are directly related to livability. With estimates that over 75% of the global population will be living in cities by mid-century, scholars, practitioners, and government officials are asking what cities can do to address the pressing social and environmental challenges that emerge from climate change. They are also seeking to learn how this knowledge may inform policy decisions regarding physical, social, and economic planning to ensure an inviting quality of life and livability in these future places. We believe that we have an unprecedented opportunity to use our knowledge, technology, and social capacities to reduce the likelihood of producing a catastrophic future.

This study compares the livability of two seemingly unlikely locations – Doha, Qatar, a capital city on the Arabian Gulf, and Portland, Oregon, an important American city in the Pacific Northwest. These cities are growing at different rates, have diverse cultural histories and varied development patterns, yet are attempting to improve urban livability for citizens in each place and its surrounding region. Through an in-depth examination of the physical changes that have occurred in both places and their corresponding urban climate conditions, especially thermal comfort, we describe the similarities and differences that help to define the challenges facing the management of each. We look specifically at two important empirically-derived measurements of livability: air quality and urban heat island effect. By focusing on these environmental stressors in each place, we are able to evaluate the extent to which different growth and policy drivers have impacted the ability for people to enjoy a desirable quality of life in both cities – different, but appropriate to each. We include as part of our approach a conceptual framework, which describes the coupling of environmental and human conditions for which changes in development patterns have direct implications on the livability of each location.

As a result of our analysis, we offer insights about actions that show promise of managing future livability in each city and focus primarily on the ability to manipulate selected aspects of urban form – those characteristics of massing, surface materials, and tree cover that can change the air pollution and urban heat stress experience in each place. We focus specifically on landscape and site scale modifications that show promise of improving air quality and/or reducing urban heat as a stressor. Since cities around the world are looking to nature to provide benefits to city inhabitants, we emphasize the salutary role of green infrastructure.

While much is still to be discovered regarding the capacity for cities and their managers to adapt to the emerging challenges of climate change, population growth, and conventional development patterns, yet without sustained and promising actions, the cities that are home to the majority of people today may likely become either obsolete in the coming centuries or present less than desirable living conditions for their future residents.

We recognize that while all cities are unique reflections of their unique biophysical, microclimatic, social, cultural, and natural contexts, they also share many similar circumstances and conditions – the identification of which may help policy makers address climate change more effectively. Our conclusions also support the fact that seemingly diverse cities do, in fact, contain similarities in terms of the local, environmental, and urban design conditions that determine air quality and contribute to urban heat island effect.

Grant Acknowledgement: This paper was made possible by National Priority Research Program grant #NPRP 5-074-5–015 from the Qatar National Research Fund (a member of Qatar Foundation).

Keywords: Climate change, microclimate, air quality, urban heat island, thermal comfort, livability

Solar radiation in near-real time is of high importance for the integration of PV electricity into the Grid and operation of solar plants. Solar radiation is characterized by a high temporal and spatial variability mainly due to the effect of clouds. In the case of solar energy plants with storage energy system and CSP plants in general, its management and operation need reliable predictions of solar irradiance in the very short term or nowcasting. Solar forecasts are also needed in on-grid applications of solar energy where sudden changes in solar irradiance can trigger unacceptable voltage deviation, if not properly managed. Solar radiation forecasting beyond six hours and up to several days ahead is based on Numerical Weather Prediction (NWP) models for supplying hourly or daily forecasted values. However, statistical and machine learning techniques have shown to be effective for solar forecasting at higher-resolution timescales (e.g. minutes). The aim of this work is to show the effectiveness of autoregressive models for the prediction of solar radiation in the short term (nowcasting) in the Middle East. The temporal steps of the predictions are 1, 5 and 10 minutes, and the temporal horizon is 15 steps ahead, so that the ensuing predictions includes 15, 45 and 150 minute ahead forecasts, respectively. We describe the models and show validation results for one year of ground measured global horizontal irradiance in Doha (Qatar).

Cobalt hydroxide or cobaltous hydroxide or cobaltous hydrate, has attracted increasing attention in recent years because of its novel electric and catalytic properties and important technological applications, for examples in advanced batteries, supercapacitors, solar cells, electrochromics, as an oil additive, it can improve tribological properties [1,2], etc. Cobalt hydroxide nanoparticles were prepared via in-situ electrospinning. Thus, electrospinning of polyethylene oxide solution with different cobalt nitrate concentrations were carried out in gaseous ammonia atmosphere. The reaction of cobalt nitrate with ammonia produces cobalt hydroxide. The reaction occurs during fiber formation. Transmission Electron Microscopy (TEM) showed that cobalt hydroxide Co(OH)2 nanoparticles were formed on the produced nanofibers of 100-600 nm in diameter. The existence of the formed Co(OH)2 was also proven by X-ray Diffraction (XRD) analysis and it showed that the Co(OH)2 nanoparticles were produced. Thermogravimetric Analysis (TGA) results also confirmed the presence of Co(OH)2 within the fibers. Experimental Section Co(NO3)2.6H2O (supplied by Merck Chemical Co.) with different concentrations was dissolved in 100 mL distilled water to produced Co+2 solution. Then, the following seven experiments (Exp. G1, G2, G3, G4, G5 (collectively called G-series in this article), P, and N) were carried out. G-series: 4.0 g of polyethylene oxide (with weight average molecular weight of 600,000 g/mol and supplied by Acros Organics Co.) was added to 100 mL of above mentioned cobalt nitrate solution with different concentrations (given in Table I) and left for two nights to obtain a homogenous PEO solution having cobalt ions. The polymer solution was put into a hypodermic syringe. A syringe pump (Stoelting Co., USA) was used to feed the polymer solution into a metallic needle with an inner diameter of 0.7 mm. A grounded aluminum foil as collector was placed at a fixed distance of 18 cm from the needle. The metallic needle and the collector were enclosed in a polymethyl metacrylate box (40′50′60 cm). The feed rate of the syringe pump was fixed at 0.7 mL/h. A positive potential of 18 kV was then applied to the polymer solution using a high-voltage power supplier (HV35P series, Fnm Co., IR) with a maximum voltage of 35 kV. During electrospinning, gaseous ammonia (from a cylinder purchased from Merck Chemical) was purged into the box with a rate of 10 L/min. Electrospun nanofibers were collected on the surface of the grounded aluminum foil. Results and Discussion A comparison of the appearance (color change) of the mats obtained from G-series with that of the P fiber mat suggested that the cobalt ions in the jet traveling the distance between the needle and the collector could precipitate in the gaseous ammonia atmosphere to produce cobalt hydroxide. In other words, in this process, one reaction occurs during fiber formation: the reaction of Co+2 ions with NH3 which produces Co(OH)2 nanoparticles on the nanofibers. Cobalt (II) hydroxide is obtained as a precipitate when an alkaline hydroxide is added to an aqueous solution of cobalt (II) salt. Since the reaction of nanoparticle formations occurs during fiber formation in electrospinning process, the precipitated nanoparticles have special morphology and crystalline structures (due to the applied voltage, elongation, etc.). Figure 1 displays the TEM images of fibers obtained from Exp. G1 (electrospinning of polyethylene oxide solution having 2.5% Co+2 based on PEO, in ammonia atmosphere) and as it shows, dark spots of Co(OH)2 are heterogeneously dispersed on the fibers. These TEM images suggest that in the Exp. G1, Co(OH)2 nanoparticles were heterogeneously synthesized on fibers through the reaction of cobalt ions with NH3. Fig.1 TEM images of nanofibers obtained from Exp. G1. Ref. Zhang, L.; Dutta, A.K.; Jarero, G.; Stroeve, P. Nucleation and growth of cobalt hydroxide crystallites in organized polymeric multilayers. Langmuir, 2000, 16, 7095. Patnaik, P.; Handbook of Inorganic Chemicals, McGraw-Hili, New York, 2002.

In this review the results of many unclassified homemade optical detectors developed in the last two decades at the research and patents bases in Iraq is demonstrated. These detectors include: CdS doped with Cu (CdS:Cu); CdSe; CdSe:Cu; PbS; and PbSe. They cover a wide range of the electromagnetic spectrum ranging from the solar spectrum to the infrared (0.4-10.6 μm). It is found that for the CdS and CdSe type of the detectors, the wavelength tuning are due to the localized energy states of copper atoms inside the valence and conduction band of the CdS and CdSe. The tuning of these photoconductive detectors is compared with the recent quantum well (QWIR) and quantum dots (QDIR) infrared detectors. The major significance of the developed detectors is their synthesis simplicity and very low cost in comparison with that of the QWIR and the QDIR detectors. The CdS:Cu which covers the spectral response range (0.4-0.7 μm) is prepared by using a chemical spray pyrolysis. The CdSe:Cu is found to cover a wider spectral response than that of the CdS:Cu (0.4-10.6 μm). This detector is prepared by vacuum evaporation of CdSe films on glass substrate followed by vacuum annealing under an argon atmosphere for doping of copper. A high gain value of 2.37-107 is measured and explained by the competition of the copper capture cross section. Such competition produces further carriers due to the photoexcitation of copper atoms in the localized states inside the band gap. For the CdSe detector, it is found that vacuum annealing improves the detector characteristics such as the gain. Moreover it is found that the gain increases from 4.3 to 12 when the annealing temperature was increased from 150 to 350°C respectively. However, the doping of CdSe with copper leads to a huge increase of the gain coefficient to about 9-103. On the other hand the PbxS1-x alloys (spectral response 1-2.8 μm) were prepared from pure lead and sulfer powders with two x contents (0.54, 0.55). They were loaded into a clean and baked quartz tube. It is found that the quantum efficiency, responsivity and detectivity of the prepared detector are improved with the little increase of the Pb content from 0.54 to 0.55. As for the PbSe film detector (response range 2-5 μm), the responsivity and quantum efficiency are found to increase by lowering the detector temperature to 180K. It is focused on a brief review of the figure of merits of the mentioned detectors. Moreover these detectors are used for the detection of various laser wavelengths in a pulsed mode of operation and can be used in military areas, particularly, for the detection of thermal targets.

Qatar has no rivers, thus the main natural water resource in Qatar is the groundwater table. The average groundwater recharge from rainfall is approximately 55.9 million m³/year, in addition to 2.2 million m³/year inflow of groundwater from Saudi Arabia, i.e. the total average renewable groundwater resource is 58.1 million m³/year for the period 1972-2005. Desalinated sea water and treated sewage are non-conventional water sources in Qatar. The quantities of produced and treated wastewater in the country were 55 and 53 million m³ in 2005 respectively. In 2005, a total water withdrawal of 444 million m³ was estimated, which are divided unequally into agricultural, municipal and industrial purposes. The Permanent Water Resources Committee (PWRC) was established in April 2004 to secure water resources for various uses for the benefit of Qatar. Qatar has carried out a number of studies, and established committees for the unification of integrated water resources management as follows: Increasing natural recharge by drilling wells with a special design. Development of water monitoring and irrigation scheduling. Artificial recharge of groundwater. Development of deep aquifers. Increasing treatment and reuse of waste-water: The amount of treated sewage increased from 46 million m³ in 2004 to 58 million m³ in 2006. All of the above mentioned facts clarify the importance of securing water (quality and quantity) for the state of Qatar. Many disease-causing germs may be present in water supplies. Sixty percent of all persons living in developing countries live without an adequate supply of drinking water where unsafe water is a major cause of infant mortality in these countries. Table 1 lists some of the germs that inhabit water and which can be harmful to humans. Table 1: Water inhabiting germs Germs Minimum dose for infection Survival time in water, days Escherichia coli 1,000,000 4-16 Vibrio cholera 3 7-32 Campylobacter jejuni 500 16-49 Salmonella typhi 3 4-35 Hapatitis Type A 1 Unavailable Entamoeba coli 10 10-16 Giardia lamblia 10 16-77 Water disinfection processes kill micro-organisms in the drinking water. Disinfection can be achieved by means of chemical disinfectants such as chlorine, which is the most commonly used chemical for disinfection because of its low price. It also remains in water, which inhibits reproduction and growth of the germs. However, this process may produce toxic disinfection byproducts which are very harmful to human health. Other disinfection processes such as ozonization or ultraviolet light are expensive for drinking water disinfection. The objective of this work is to implement an electrical disinfection process for controlling germs in water, since the germ cells are destroyed when the electric field strength and pulse duration are above critical values, i.e. dielectric breakdown of the cell membrane. In electrical disinfection water treatment techniques, the high voltage sources used can be classified into: high voltage DC generators, high voltage AC generators, and high voltage pulse generators. The main disadvantage in case of continuous DC sources is the degradation effect on electrodes (electrolysis of electrodes). Although the electrolysis is less in case of AC sources, the AC field application has a dead band region. Since the application time is of the order of a few milliseconds, some bacteria may pass through the electrodes when the electric field has a low strength. On the other hand, pulsed electric field is an effective solution to guarantee killing all harmful germs and avoid electrolysis of electrodes. In PEF processing, water is passed through a small treatment chamber where it is subjected to a short pulse of very high voltage. The high voltage field created across the liquid kills microorganisms by disrupting cell membranes. By applying a high PEF with of sufficient pulse width, an electrical discharge in water will occur. The electric discharges in water can effectively create a variety of simultaneous aspects such as shock waves, ultraviolet radiation, and the formation of chemically active radicals acting on biological cells and chemical compounds dissolved in water. Generally, there are two main types of PEF treatments, namely, underwater pulsed corona discharge and pulsed arc discharge. In corona discharge, the streamer filaments do not propagate across electrodes gap, while in case of arc discharge, the streamers bridge the electrodes. As a result, the pulsed corona has lower power requirements compared to the pulsed arc discharge. In this work, underwater pulsed corona discharge will be considered. In this work, a new grid-connected high-voltage pulsed power generator is proposed to generate pulsed streamers and plasma inside water, which will react with germs and destroy them.

The proposed generator consists of:

•   (i) Uncontrolled full-bridge rectifier to rectify the grid voltage,
• (ii) DC-DC Boost Converter (BC) in conjunction with Capacitor-diode voltage multipliers (CDVMs) to assure operating with unity input power factor (PFC feature) and elevate the rectified voltage to a proper voltage level,
• (iii) Conventional solid-state Marx generator, as the generated voltage from BC and CDVMs stage is used to charge the Marx generator capacitors (which are connected in parallel during the charging process),

then when it is needed to generate a pulse, these capacitors are connected in series to discharge in the load during the pulse duration. The charging and discharging cycles are repeated sequentially to generate train of repetitive pulses. The load here is the water to be purified, which electrically can be represented as a resistive load. The value of this resistance depends on the conductivity of water, i.e. depends on the amount of dissolved salts in the water. The generated high voltage pulse is applied across high voltage electrodes, and the water sample to be treated should exist between these two electrodes. The generated pulsed electric field has the ability to kill germs in the water, since by applying the pulsed electric field, an ultraviolet radiation will be produced and will destroy the structure of the germs.

The main advantages of the proposed approach can be summarized as follows:

•   (i) The proposed generator has no step-up low frequency transformer which reduces the generator weight and volume and enhances the generator efficiency.
• (ii) The proposed generator can draw a sinusoidal input current at unity power factor thanks to the existence of PFC feature provided by the BC.
• (iii) Relatively low voltage semiconductor devices and capacitors will be employed which affects positively on the cost, i.e. it can be considered as a cost effective high-voltage pulse generator for domestic applications.