322,937 research outputs found
Production, purification and characterization of mid-redox potential laccase from a newly isolated Trichoderma harzianum WL1
No full textModeling the mitigation of seawater intrusion by pumping of brackish water from the coastal aquifer of Wadi Ham, UAE
No full textThe control and management of seawater intrusion in coastal aquifers is a major challenge in the field of water resources management. Seawater intrusion is a major problem in the coastal aquifer of Wadi Ham, United Arab Emirates, caused by intensive groundwater abstraction from increased agricultural activities. This has caused the abandonment of salinized wells and ultimately affected farming activities and domestic water supply in the area. In this study, the 3D finite element groundwater flow and solute transport model is developed using FEFLOW to simulate pumping of brackish water from the intrusion zone to control seawater intrusion in the aquifer. The model was calibrated and validated with available records of groundwater levels and salinity distribution. Different simulation scenarios were conducted to obtain optimum pumping locations, rates as well as a number of wells. A comparison between scenarios of non-pumping and pumping of brackish water was conducted. Results showed an increase in the concentration of groundwater salinity under the non-pumping scenario, while it decreased under the pumping scenario. Under the non-pumping scenario, isoline 30,000 mgl−1 was observed to have intruded into the south-eastern part of the aquifer, while the maximum isoline observed for the same area under the pumping scenario was 20,000 mgl−1. This result showed an overall improvement in the quality of groundwater and ultimately halted seawater intrusion in the aquifer
Impacts of regional climate model projected rainfall, sea level rise, and urbanization on a coastal aquifer
No full textThe objective of this study is to assess the impact of climate change induced rainfall, sea level rise, and urbanization on a fragile coastal aquifer. This study was carried out in one such an aquifer located in Southeast India. Downscaled climate projection was carried out using the regional climate model (RCM) with seven ensembles and the best matching ensemble for the study area has been taken to quantify the rainfall in future. The changes in land use and land cover were estimated using remote sensing techniques, and background information on sea level rise at local and regional scale were investigated. Numerical simulation of groundwater in this isolated coastal aquifer was carried out to understand the responses of the groundwater level to downscaled projected rainfall, sea level rise, expected urbanization, and their combinations until the year 2050. The RCM-projected rainfall shows a decline in the groundwater level and shrinking of the freshwater lens. However, the prediction for change in the groundwater level combined with sea level rise minimizing a decline in the groundwater level. The rapid changes in land use and land cover pattern as inferred by change detection were extended and examined in the aquifer’s future characteristics by increasing and decreasing groundwater pumping with RCM-projected rainfall recharge and with sea level rise. The results without considering sea level rise show that the aquifer undergoes degradation even if pumping is reduced by 10%. The simulation with sea level rise shows that the aquifer behaves better in maintaining freshwater lens even with 10% increase in groundwater pumping. Sea level rise prevents the availability of the freshwater lens by reducing groundwater decline caused by the reduced RCM-projected rainfall and predicted groundwater demand. Huge variation and seasonal fluctuation in the volume of outflow to the sea is noticed between north and south. Also, reduced outflow against a range of sea level rise confirms that the sea level rise in the study area will lessen the volume of outflow, will reduce the groundwater decline, and will allow an increase in groundwater level. On the other hand, the shrinking of area will decrease the freshwater volume and occurrence of reduced groundwater gradient against sea level rise will increase the possibility of seawater intrusion to pumping. The present study confirms that even with RCM-projected decrease in rainfall recharge, the increase in the sea level will help to prevent groundwater decline in this aquifer by controlling an elevation of the groundwater level. Meanwhile, it is reducing the volume of freshwater and increasing the possibility of further seawater intrusion. Hence, it is recommended to reduce the groundwater pumping from this aquifer
Dynamics of coastal aquifers. Conceptualization and steady-state calibration of multilayer aquifer system-Southern coast of Emilia Romagna
Full text linkWorldwide, coastal aquifers have been heavily exploited by socio economic activities for several decades, and climate change and sea level rise have also been threatening coastal aquifers. The authorities and policymakers have been advised to find the solutions in order to achieve sustainable water resources management. The southern part of Po delta, Italy is a low-lying coastal area also experiencing tectonic activity. Along with low-lying topography, unstable shore line and sea level, the groundwater is heavily exploited by this deltaic multilayered system of aquifers. Hence, a multilayer three-dimensional model of this aquifer system has allowed for the investigation of the response of aquifer to natural and anthropogenic exploitation. The present work regards the conceptualization of the multilayer aquifer system using lithological cross-sections, surface water features, and appropriate boundary conditions and the steady-state flow modelling. The spatially distributed elevations of the groundwater table and piezometric head from the different aquifers have been calibrated. The values of model error statistics at a satisfactory range, such as R-squared, mean error, root-mean-squared error and model efficiency, confirm that the developed model is reliable, and calibration is obtained with good match between observed and simulated data. The developed model can be used as a decision-making tool for the authorities and policymakers in order to plan for sustainable water management
Gender, genetics, and analgesia: understanding the differences in response to pain relief
Full text linkSenthil Packiasabapathy, Senthilkumar Sadhasivam Department of Anesthesia, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, USA Abstract: Genetic variations and gender contribute significantly to the large interpatient variations in opioid-related serious adverse effects and differences in pain relief with other analgesics. Opioids are the most commonly used analgesics to relieve moderate-to-severe postoperative pain. Narrow therapeutic index and unexplained large interpatient variations in opioid-related serious adverse effects and analgesia negatively affect optimal perioperative outcomes. In surgical, experimental, chronic, and neuropathic pain models, females have been reported to have more pain than males. This review focuses on literature evidence of differences in pain relief due to multiple genetic variations and gender of the patient. Keywords: pain, analgesia, pain genomics, pharmacogenomics, pharmacokinetics, pharmacodynamic
Assessment of Aquifer Storage and Recovery (ASR) feasibility at selected sites in the Emirate of Abu Dhabi, UAE
No full textAquifer storage and recovery (ASR) is considered as a strategy for the storage of water to ensure a sustainable water supply in the Abu Dhabi emirate. Earlier investigations have been conducted, and two sites were proposed for the installation of ASR in the surficial aquifer. Recently, the site located in the center of Abu Dhabi (sand dune area) was executed, and the second site is undergoing the pilot phase of the study. However, the performance and influence of the regional groundwater system may vary depending on regional hydrogeological characteristics, which have not been investigated. Hence, this study attempts to understand the feasibility of the proposed ASR sites in the surficial aquifer using a regional model developed by the finite-difference approach with an accuracy of 0.28 m mean residual difference. Additionally, six sites were selected on the basis of the literature and aquifer parameters and were investigated for their suitability for future ASR installation. Six cycles of injection and recovery at various rates were analyzed at each ASR site by using a transient calibrated model until the end of the year 2030. The area of influence is axisymmetrical in the sand dune area and non-symmetrical in the east and northeastern areas because of the steep topography and groundwater table gradient. At the sites that possess a non-symmetrical influence, the area of influence is always high upstream of the groundwater flow. Heterogeneity-induced variation in the fluctuation of the groundwater table is noted in all sites. Even with 100% recovery, the groundwater table did not reach the ambient groundwater table during the recovery period. This finding confirms the contribution of regional groundwater to the site during recovery. All sites selected for future ASR installation, except site 5, are capable of storing the volume needed to meet expected water demand. Site 2 is considered the most suitable site for ASR installation in the future. This study will facilitate the scientific communities and authorities in understanding the feasibility of ASR installation for sustainable water storage and supply in the Abu Dhabi emirate
The development of iron-free partially stabilized cement for use as dental root-end filling material
No full textNdong F, Sadhasivam S, Lin F-H, Savitha S, Wen-Hsi W, Lin C-P. The development of iron-free partially stabilized cement for use as dental root-end filling material. International Endodontic Journal, 45, 557564, 2012. Abstract Aim To determine the effect of increasing the proportion of zinc on partially stabilized cement (PSC) produced using a one-step sol gel process. Methodology A one-step sol-gel process of Portland cement-based PSC with Zn was synthesized by replacing iron nitrate. The crystalline phases of the PSC-Zn powder were analysed by using X-ray diffraction (XRD). The experimental groups [i.e. MTA, PSC-Fe (control), PSC with 1% Zn, PSC with 3% Zn, and PSC with 5% Zn] were immersed in simulated body fluid for 3 h, 1 and 3 days to evaluate the hydration product formation. The microstructure and surface morphology were analysed using scanning electron microscopy (SEM). Initial and final setting times of the materials were determined using an ASTM Vicat needle testing machine. To evaluate the cytotoxicity of PSC-Zn system, primary osteoblasts cell lines were used. Results The addition of increased weight percentages of Zn, resulted in a more unstable phase which favoured the formation of a monoclinic structure of C3S with an increased hydration reaction of PSC and reduced setting time. The cytotoxicity testing of PSC with Zn revealed that the material was not toxic. Conclusions The newly synthesized PSC-Zn material had short setting time and was biocompatible
A geo-spatial approach to perceive the groundwater regime of hard rock terrain- a case study from Morappur area, Dharmapuri district, South India
No full textThe goal of the present study is to identify the groundwater regime of Morappur area at Dharmapuri district, India. The study area covers an area of 410 sqkm. The area belongs to a hard rock terrain where the primary porosity is feeble and the secondary porosity offered by fracture, joints and shear zones etc, contributes to the groundwater regime. The availability of surface water resources is sparse and hence the groundwater repositories are intensely utilized. In the current study area, the availability of groundwater is limited due to scanty rainfall and poor recharge. The entire study area underlain by hard crystalline rocks of Archaean age, Charnokite and Hornblende epidote gneiss are the main rock types encountered in the area. The over exploitation of these resources more than the adequate recharge has resulted to decrease in the groundwater level. In this context, it is very much important to identify and understand the groundwater regime of this area for the better groundwater monitoring and conservation of this precious resource. Remote Sensing and GIS are playing a vital role in the advancement of hydro-geological studies. The use of conventional methods alone has its own limitations in comprehending the groundwater regime of the area. The integrated study using remote sensing, field studies together with GIS has helped to understand the role of structural, lithological and geomorphic units in controlling the groundwater occurrence and movement in the present study area. Various thematic maps were prepared from the satellite images and they were integrated and incorporated in a GIS platform along with collateral information to study the groundwater regime of Morappur area. The outcome of this study clearly shows the importance of the geospatial studies in identifying the role of satellite imageries and geospatial techniques to understand the groundwater regime of a hard rock terrain
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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