838 research outputs found

    Today we are all Osama: jihadists’ reaction to Bin Laden’s death (guest blog)

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    One of Al Qaeda’s most potent tools is the Internet. It acts as a communication and recruitment platform for the loose network of ‘jihadist’ activists and their supporters around the world. Mina Al-Lami is a research fellow at the LSE who has been monitoring these sites over the last few years. Here is her fascinating account of the way they responded to the death of Osama Bin Laden

    Ecological restoration of lead/zinc/copper mine tailings: Phytomanagement and amendment strategies to enhance substrate functionality and biomass production

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    “The extreme physiochemical characteristics of mine tailings inhibit microbial processes and natural plant growth. Consequently, vast and numerous tailings sites remain barren for decades and highly susceptible to wind and water erosion. Phytostabilization is a cost-effective and ecologically productive remediation approach; however, tailings revegetation is generally challenging and must often be assisted with appropriate soil amendments. Amendments applied individually in greenhouse studies discussed herein revealed notable improvement in bioenergy crops growth only with biosolids treatments. Recalcitrant carbon amendments (biochar and humus) showed notable impact only on tailings physichochemical and hydraulic properties. Nevertheless, biosolids may not support sustained vegetation due to their nutrient lability and rapid decomposition. Therefore, strategies to sustain phytostabilization were evaluated by co-applying biosolids with recalcitrant carbon or biological amendments to synergistically ameliorate tailings characteristics while supporting sustainable growth to stimulate soil formation. Co-applying with biochar exhibited efficient nutrient release while concurrently reducing metal availability and uptake. Co-applying with mycorrhizal fungi further improved biomass production, increased organic matter input, and reduced metal bioavailability and uptake. To non-destructively assess plant health, a rapid screening approach was also developed utilizing computer vision and imaging techniques. A wide range of native species was also screened for potential to revegetate mine tailings for greater ecosystem benefit and utilizing the developed approach greatly facilitated quantification of plant responses to phytomanagement strategies for mine-impacted sites”--Abstract, page iv

    Controlling ZnO Nanostructure Morphology on Seedless Substrate by Tuning Process Parameters and Additives

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    In this, article ZnO nanostructure synthesized on seedless Si substrate by hydrothermal process using nutrient solution. Low concentration, 5 and 10 mM, equi-molar nutrient solution composed of zinc nitrate and hexamethylenetetramine (HMTA) and high concentration of 25 mM zinc nitrate and 12.5 mM hexamethylenetetramine (HMTA) with and without NH4.OH additions  were used to synthesis ZnO nanostructure. The effect of precursor’s concentration, growth temperature, and time were studied. The effects of these parameters on morphology and structure were investigated via SEM and XRD. It was found that the morphology reflect the dominate growth direction that could be tuning by controlling above parameters. High-density forest nanostructure achieved from high concentration nutrient solution with NH4OH addition. Keywords: hydrothermal, ZnO nanostructure, morphology, additive, and growth direction

    SCCOF: smart cooperative computation offloading framework for mobile cloud computing services

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    Virtual reality games and image processing Apps are examples of mobile cloud computing services (MCCS) common on Smartphones (SPs) nowadays, requiring intensive processing and/or wireless networking. The consequences are slow execution and huge battery consumption. Offloading the intensive computations of such Apps to a cloud based server can overcome such consequences. However, such offloading will introduce time delay and communication overheads. This paper proposes to do the offloading to nearby computing resources in a cooperative computation sharing network via short-range wireless connectivity. The proposed SCCOF reduces offloading response time and energy consumption overheads. SCCOF is supported by an intelligent cloud located controller that will form the cooperative resource sharing network on the go when needed, based on available devices in the vicinity, and will use the cloud if necessary. Upon the initiation of the MCCS service via the App, our controller will devise the offloaded VMs as well as the offloading network. A study test scenario was performed to evaluate the performance of SCCOF, resulting in saving of up to 16.2x in execution time and 57.25% energy

    Sizing and Thermal Stability of Prepared Tetraaminophthalocyaninatocopper(II) Derivatives-grafted Polymers

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    Different polymers were prepared by condensation polymerization of sebacic anhydride and adipic anhydride with ethylene glycol and poly(ethylene glycol). Their number average molecular weights were determined by end group analysis. Then, they were grafted on the prepared phthalocyaninatocopper(II) compounds with the general formula (NH2)4PcCu(II) having amino groups of 3,3',3'',3'''- or 4,4',4'',4'''- positions. All prepared polymers, compounds, and phthalocyaninatocopper(II)-grafted polymers were characterized by FTIR. The sizing measurements were carried out in 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) compounds with and without grafting polymers. The results showed that the grafting process led to decreasing in particle size and increasing in surface area. The grafting process was reflected positively on the thermal degradation of 3,3',3'',3'''- (NH2)4PcCu(II) and 4,4',4'',4'''- (NH2)4PcCu(II) grafted polymers. They had higher thermal stability accompanied with higher char residue and T50% weight loss with 3,3',3'',3'''-(NH2)4PcCu(II) and their grafted polymers being the best

    Synthesis, characterization and thermal properties of the nano four arms poly(pentaerythritollactide-b-N,N-dimethylaminoethyl methacrylate) derivatives

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    The nano four arms poly(lactide-b-N,N-dimethylaminoethylmethacrylate) were prepared by pentaerythritol-lactide atom transfer radical polymerization initiators having different repeating units (10, 25, 50 and 100) of L-lactide with the same amount of N,N-dimethylaminoethyl methacrylate by atom transfer radical polymerization reaction. The copolymers were characterized FT-IR, 1H NMR, 13C NMR and Gel permeation chromatography. These characterization methods confirmed the structures of prepared copolymers. Scanning electron microscopy, on the other hand, revealed that the presence of a nanostructure in the prepared copolymers attributed to the lactide fibers. Then, the thermal study was carried out on the copolymers the results have proven to increase the thermal stability of the copolymers with the increasing chain length of the lactide

    Assessment of spatial distributions of some climate indices in Iraq

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    Aridity is one of the main factors which distinguish the climate of a region and has significant influence on human activities. This study investigated the spatial distribution of the aridity indices to determine the climate conditions in Iraq over the period (1981-2015), depending on the data of the air temperature and rainfall which obtained from 28 stations distributed through Iraq. The used aridity indices are: Lang, Erinc, Emberger, UNEP, De Martonne and Thornthwaite. The spatial distribution was determined using inverse distance weighting (IDW) interpolated method. The results of aridity indices analysis shows that the hyper-arid, arid, and semi-arid categories are predominant with almost (91%) to (100%) of the country’s area. Dry sub-humid, moist sub-humid and humid categories occupies less than (10%) with most of indices at stations of (Arbil, Sulaymaniyah, and Salahaddin). To evaluate the seasonal spatial distributions, De Martonne was utilized. During winter, the climate types ranged from semi-arid to very-humid, while at spring season from arid to humid. Autumn season dominated by arid at (97%) of study area. The summer season was the driest compared with the other seasons. The change point for aridity indices was detected by using the cumulative sum charts (CUSUMs), it is found for the most stations in (1997). Consequently, the spatial distribution for the aridity indices were analyzed through two periods (1981-1997 and 1998-2015), this analysis showed that the arid and hyper-arid areas were increased in the second period compared with the first period with obvious extension toward the north of Iraq.

    Al-Qa'ida's Virtual Crisis

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