2,057 research outputs found

    e-Learning: The nextbig thing in medical education

    Get PDF
    No Abstract

    Assessing impacts of sea level rise on seawater intrusion in a coastal aquifer with sloped shoreline boundary

    Get PDF
    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.International Association for Hydro-environment Engineering and Research, Asia Pacific Division.This paper investigates the effect of gradual and instantaneous sea level rise (SLR) on the seawater intrusion (SWI) process in coastal aquifer systems with different levels of land-surface inundation. A set of hypothetical case studies with different shoreline slopes is used to conduct this numerical experiment. For the purpose of numerical modelling, a future rate of SLR from 2015 to 2100 is considered based on the moderate expectation of the Intergovernmental Panel on Climate Change (IPCC, 2001). The gradual SLR is implemented in two different stages. First, continuous and nonlinear rising of sea level is imposed starting from year 2015 up to the end of the century. After that the final value of sea level is maintained as constant in order to assess the response time spanning to a new steady state condition. The effects of pumping resulting in lowering of groundwater level are also considered together with the dynamic variation of sea level. The results show that the rate and the amount of SWI are considerably greater in aquifers with flat shoreline slopes compared with those with steep slopes. Moreover, a shorter period of time is required to reach a new steady state condition in systems with flatter slopes. The SWI process is followed by a significant depletion in quantity of freshwater resources at the end of the century. The situation is exacerbated with combined action of SLR and over-abstraction. Finally, by considering the effect of inundation of the shoreline due to gradual SLR, the sensitivity of the system to the main aquifer parameters including molecular diffusion of solute, dispersion, hydraulic conductivity and porosity is investigated

    Three dimensional simulation of seawater intrusion in a regional coastal aquifer in UAE

    Get PDF
    Published13th Computer Control for Water Industry Conference, CCWI 2015In this study the vulnerability of the Wadi Ham aquifer, located in the Fujairah Emirate of the UAE, to seawater intrusion (SWI) is assessed using a 3D finite element (FE) model. The numerical model is developed based on available hydrogeological data in real scale. By simulation of the aquifer for the next 10 years and by maintaining the current rates of pumping (in year 2015), the progress of seawater intrusion in year 2025 is followed by further depletion in freshwater storage of the Wadi Ham aquifer. In order to control this problem, the model is subjected to a management strategy involving surface recharge of the aquifer with treated wastewater

    Control of saltwater intrusion by aquifer storage and recovery

    Get PDF
    This is the final version of the article. Available from the publisher via the DOI in this record.Published Online 18th August 2016This paper presents the results obtained from the application of aquifer storage and recovery (ASR) technique to control seawater intrusion (SWI) in coastal aquifers. The study is based on the numerical modelling experiments performed using the SUTRA (Saturated–Unsaturated TRAnsport) finite-element code on the Wadi Ham aquifer in the UAE. A three-dimensional numerical model of this aquifer is developed and calibrated based on the available hydrogeological data in real scale. A significant amount of SWI has been calculated for the year 2015 due to the high rates of pumping from the available local well fields. To study the future responses of the aquifer to different control actions, the transient responses of SWI are simulated over a 10-year planning horizon. The proposed management measure (ASR) is implemented in repeated cycles of artificial recharge, storage and recovery using an additional set of wells defined in the model. The results show that ASR is a reliable method in controlling SWI in coastal aquifer systems besides its conventional role in subsurface water banking.The authors acknowledge their gratitude to the British Council, UK, for providing funding (project code: SH-04509) to support this research

    Porous ZnO/Carbon nanocomposites derived from metal organic frameworks for highly efficient photocatalytic applications - A correlational study

    Get PDF
    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Porous ZnO/C nanocomposites derived from 3 different Zinc based metal-organic frameworks (MOFs) including MOF-5, MOF-74 and ZIF-8, were prepared at high temperature under water-steam atmosphere and their performances in photocatalytic H 2 evolution reaction (HER) and photodegradation of organic dye pollutants were evaluated. The formation mechanism from MOF precursors, the structural properties, morphologies, compositions and textural properties of the derived ZnO/C composites were fully investigated based on different characterization techniques and the correlation between the precursors and the derived composites was discussed. It is evident that MOF precursors determine the crystalline structures, doping profiles, thermal stabilities and metal oxide-carbon weight percentage ratios of the resulting composites. The correlation between MOFs and their derived nanocomposites indicates that different parameters play unalike roles in photocatalytic performances. The desired properties can be tuned by selecting appropriate MOF precursors. MOF-5 derived porous ZnO/C nanocomposite not only exhibits the highest photocatalytic dye degradation activity under visible light among these MOFs, but also outperforms those derived from MOF-74 and ZIF-8 up to 9 and 4 times in photocatalytic HER respectively. This study offers simple and environmentally friendly approaches to further develop new homogeneously dispersed functional metal oxide/carbon composites for various energy and environment-related applications.Engineering and Physical Sciences Research Council (EPSRC)European Commissio

    Effect of lead acetate administered orally at different dosage levels in broiler chicks

    Get PDF
    The project was conducted to evaluate the effect of lead administered as lead acetate at different dosage levels via drinking water in broiler chicks. Thirty-five healthy chicks were divided into seven groups (five chicks each) and one group was kept as un-medicated control. Groups A, B, C, D, E and F were medicated with lead acetate in a single dose at a rate of 80, 120, 160, 200, 240 and 280 mg/kg of body weight respectively for twenty five days consecutively. Various biochemical parameters, that is, glutamate pyruvate transaminase, creatinine and uric acid were determined by using spectrophotometer. A significant (P<0.05) increase was recorded in GPT, creatinine and uric acid levels in all medicated groups. The GPT, creatinine and uric acid levels were significantly (P<0.05) higher in groups medicated with high doses of 240 and 280 mg/kg b.wt of lead acetate. Analysis of variance showed that the DATA were significant not only from the single factor (dose/days) point of view, but also from their combined effect (dose rate × different days of analysis), which gave significant results with a P value less than 0.05. The mortality rate of 20% was observed for the groups medicated with 120, 160 and 200 mg/kg b.wt, while 60% was observed for the groups medicated with 240 and 280 mg/kg b.wt. Postmortem revealed gross lesions on liver, lungs, kidney and brain at high doses of lead acetate. The lead was also accumulated in different organs, such as, the bone (14.83 ± 0.18 μg/g), brain (2.63 ± 0.16 μg/g) and liver (1.05 ± 0.16 μg/g). These results showed that lead possessed significant capability of bioaccumulation. However, it also revealed that lead toxicity increased as the dose increased and high dose of lead caused both hepatotoxicity and nephrotoxicity in broiler chickens.Keywords: Lead acetate, hepatotoxicity, nephrotoxicity, broiler chicken

    Stellar Coronal and Wind Models: Impact on Exoplanets

    Full text link
    Surface magnetism is believed to be the main driver of coronal heating and stellar wind acceleration. Coronae are believed to be formed by plasma confined in closed magnetic coronal loops of the stars, with winds mainly originating in open magnetic field line regions. In this Chapter, we review some basic properties of stellar coronae and winds and present some existing models. In the last part of this Chapter, we discuss the effects of coronal winds on exoplanets.Comment: Chapter published in the "Handbook of Exoplanets", Editors in Chief: Juan Antonio Belmonte and Hans Deeg, Section Editor: Nuccio Lanza. Springer Reference Work

    The national Targeted Lung Health Checks programme: Focusing on the lungs does not mean missing adrenal lesions.

    Get PDF
    Recently, the UK's national Targeted Lung Health Checks programme produced recommendations for the management of incidental findings identified during the scans performed as part of the lung cancer screening programme. We identified significant discrepancies between the recommendations for adrenal incidentaloma management and those currently implemented into UK practice (2016 European Society of Endocrinology guidelines).This may create conflict and confusion between referrers (respiratory clinicians) and receivers (endocrinologists), with potential negative impact on patients, delay and inefficient use of resources. We also address the potential cost implications of adopting a more vigilant approach as advised by the European Society of Endocrinology.Urgent multidisciplinary and unified guidelines should be established in the interest of clinical- and cost-effectiveness

    Signatures of Star-planet interactions

    Full text link
    Planets interact with their host stars through gravity, radiation and magnetic fields, and for those giant planets that orbit their stars within \sim10 stellar radii (\sim0.1 AU for a sun-like star), star-planet interactions (SPI) are observable with a wide variety of photometric, spectroscopic and spectropolarimetric studies. At such close distances, the planet orbits within the sub-alfv\'enic radius of the star in which the transfer of energy and angular momentum between the two bodies is particularly efficient. The magnetic interactions appear as enhanced stellar activity modulated by the planet as it orbits the star rather than only by stellar rotation. These SPI effects are informative for the study of the internal dynamics and atmospheric evolution of exoplanets. The nature of magnetic SPI is modeled to be strongly affected by both the stellar and planetary magnetic fields, possibly influencing the magnetic activity of both, as well as affecting the irradiation and even the migration of the planet and rotational evolution of the star. As phase-resolved observational techniques are applied to a large statistical sample of hot Jupiter systems, extensions to other tightly orbiting stellar systems, such as smaller planets close to M dwarfs become possible. In these systems, star-planet separations of tens of stellar radii begin to coincide with the radiative habitable zone where planetary magnetic fields are likely a necessary condition for surface habitability.Comment: Accepted for publication in the handbook of exoplanet

    Management of Seawater Intrusion in Coastal Aquifers: A Review

    Get PDF
    This is the final version. Available on open access from MDPI via the DOI in this recordSeawater intrusion (SWI) is one of the most challenging and widespread environmental problems that threaten the quality and sustainability of fresh groundwater resources in coastal aquifers. The excessive pumping of groundwater, associated with the lack of natural recharge, has exacerbated the SWI problem in arid and semi-arid regions. Therefore, appropriate management strategies should be implemented in coastal aquifers to control the impacts of SWI problems, considering acceptable limits of economic and environmental costs. The management of coastal aquifers involves the identification of an acceptable ultimate landward extent of the saline water body and the calculation of the amount of seaward discharge of freshwater that is necessary to keep the saline–freshwater interface in a seacoast position. This paper presents a comprehensive review of available hydraulic and physical management strategies that can be used to reduce and control SWI in coastal aquifers. Advantages and disadvantages of the different approaches are presented and discussed.British Counci
    corecore