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GIS-based assessment of non-equilibrium pattern between groundwater recharge and irrigation draft in a semi-arid region of Rajasthan, India

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Journal of Arid Land 2016年第2期8卷 184-196页

作者： Bidyut k BHADRA Sanjay kUMAR Rakesh paliwal Regional Remote Sensing Centre National Remote Sensing Centre Indian Space Research Organisation Department of Space Jodhpur Rajasthan 342003 India krishi Vigyan kendra Central Arid Zone Research Institute Indian Council of Agricultural Research Bhuj Gujarat 370105 India

Over-exploitation of groundwater for irrigation can result in drastic reduction in groundwater level in Jodhpur district of western Rajasthan, India. In this study, we used the long-term trend analysis of seasonal groundwater level data to predict the future groundwater scenario in 33 villages of Jodhpur district, assessed the impact of water harvesting structures on groundwater recharge and explored the non-equilibrium between groundwater recharge and irrigation draft in the study area. Analysis of groundwater level data from 26 observation wells in 33 villages in the pre-monsoon period showed that groundwater level decreased continuously at the rate of 2.07 m/a. With this declining rate, most of the tube wells （including the well with the maximum depth of 193 m） are predicted to become completely dry by 2050. Behavior of temporal groundwater level data in the study period （from 2004 to 2012） can be explained by different geospatial maps, prepared using ArcGIS software. Statistical analysis of the interpolated maps showed that the area with the maximum positive groundwater recharge occupied 63.14% of the total area during 2010-2011 and the area with the maximum irrigation draft accounted for 56.21% of the total area during 2011-2012. Higher groundwater recharge is attributed to the increase in rainfall and the better aquifer condition. Spatial distribution for the changes of average groundwater recharge and draft （2008-2009 and 2011-2012） showed that 68.50% recharge area was in positive change and 45.75% draft area was in negative change. It was observed that the area of the irrigation draft exceeded that of the groundwater recharge in most of the years. In spite of the construction of several shallow water harvesting structures in 2009-2010, sandstone aquifer zones showed meager impact on groundwater recharge. The best-fit line for the deviation between average groundwater fluctuation due to recharge and irrigation draft with time can be represented by the polynom

关键词： geographic information system groundwater fluctuation water harvesting structures Jodhpur district

Influence of second phase precipitates on mechanical and in-vitro corrosion behaviour of Mg-4Zn-0.5Ca-0.8Mn alloy in optimum homogenized conditions

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Journal of Magnesium and Alloys 2023年第4期11卷 1343-1366页

作者： Darothi Bairagi Partha Duley Manas paliwal Sumantra Mandal Department of Metallurgical and Materials Engineering Indian Institute of Technology Kharagpur721302India

The present study investigates the mechanical and in-vitro corrosion behavior of Mg-4Zn-0.5Ca-0.8Mn alloy in optimum homogenized *** optimization of the homogenization parameters has been carried out employing thermodynamic calculations and kinetic *** model utilizes the inter-diffusivity of the solute elements and predicts that∼6–24 h of homogenization at 633 k effectively redistributes the elements in the Mg *** on the insights obtained from the simulations,the as-cast Mg-4Zn-0.5Ca-0.8Mn alloy was subjected to homogenization heat treatment process for 6–*** microstructural study through optical microscopy and scanning electron microscopy(SEM)revealed that the interconnected network of second phase precipitates substantially dissolve within 24 h,implying adequate ***,fine Mg-Zn based precipitates with varied morphology and phase fractions also evolved during homogenization treatment,as confirmed through SEM and transmission electron *** the 12 h homogenized specimen,the highest fraction of uniformly dispersed fine precipitates resulted in the highest strength(∼225 MPa).On the other hand,a substantial disruption in coarse precipitate network and lower aspect ratio of fine Mg-Zn precipitates led to the highest ductility(∼8%)in this *** the 24 h homogenized specimen,the ductility reduced marginally owing to higher aspect ratio of fine *** immersion and electrochemical tests(viz.,potentiodynamic polarization and electrochemical impedance spectroscopy)carried out in Hank’s solution revealed that the 24 h homogenized specimen exhibits the best corrosion *** least fraction of Ca_(2)Mg_(6)Zn_(3)phase with maximum disruption in interconnectivity,in combination with a small fraction of fine equilibrium MgZn_(2)precipitates,resulted in suppression of localized corrosion in this *** promotes the formation of the most stable and compact product layer over the specimen,result

关键词： Mg alloy Thermodynamic-kinetic calculation Homogenization EIS Passive film

Enhanced in-vitro degradation resistance and cytocompatibility of a thermomechanically processed novel Mg alloy:Insights into the role of microstructural attributes

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Journal of Magnesium and Alloys 2024年第2期12卷 700-725页

作者： Darothi Bairagi Santanu Mandal Mangal Roy Manas paliwal Sumantra Mandal Department of Metallurgical and Materials Engineering Indian Institute of TechnologyKharagpur 721302India

The role of microstructural features on in-vitro degradation and surface film development of a thermomechanically processed Mg-4Zn-0.5Ca-0.8Mn alloy has been investigated employing electrochemical studies,scanning electron microscopy and X-ray photoelectron *** specimen forged at 523 k temperature developed a coarse unimodal microstructure consisting of basal oriented grains,whereas the specimens forged at 623 k and 723 k temperatures exhibited bimodal microstructures containing randomly oriented fine grains and basal oriented coarse *** bimodal microstructures exerted higher resistance to corrosion compared to the unimodal microstructure in presence of a protective surface *** optimum size distribution of fine and coarse grains as well as the prevalence of basal oriented grains led to the lowest anodic current density in the specimen forged at 623 *** morphology of Ca_(2)Mg_(6)Zn_(3)precipitates governed the cathodic kinetics by controlling the anode to cathode surface area *** the specimen forged at 723 k comprised comparatively lower fraction of precipitates than at 623 k,the mesh-like precipitate morphology increased the effective cathodic surface area,leading to enhanced localised corrosion in the former *** microstructural features developed at 623 k forging temperature formed a well-protective surface film with lower Mg(OH)_(2)to MgO ratio,exhibiting distinctly high polarization resistance and superior cytocompatibility in terms of cell-proliferation and cell-differentiation.

关键词： Magnesium alloy Microstructure Corrosion Electrochemical impedance spectroscopy X-ray photoelectron spectroscopy Cytotoxicity

A systematic investigation of secondary phase dissolution in Mg-Sn alloys

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Journal of Magnesium and Alloys 2019年第4期7卷 725-737页

作者： Arushi Dev Niladri Naskar Nishant kumar Ashutosh Jena Manas paliwal Department of Materials Science and Engineering Indian Institute of TechnologyGandhinagarPalaj CampusGandhinagarGujarat 382355India Seoul Nation University Seoul 08826Republic of Korea

As-cast Mg-Sn alloys(3,6,and 9 wt%Sn)were solution treated at 653,703 and 753 k(380,430 and 480℃)for 1,4,8,12 and 24 h to determine the variation of secondary phase with respect to Sn content,temperature and ***-3 wt%Sn exhibits Mg2Sn dissolution at all solution treatment temperatures whereas Mg-6 and 9 wt%Sn alloy displays Mg2Sn reprecipitation and dissolution depending on the heat treatment *** addition,a combined mathematical model that predicts the secondary phase dissolution and solute redistribution as a function of temperature and time is presented in this *** model is a significant improvement compared to the previous studies where the dissolution and homogenization processes are considered *** effect of grain size and solute mobility upon the dissolution and homogenization kinetics is discussed as well.

关键词： Solution treatment Homogenization Dissolution Mg-Sn alloys

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纺丝后处理对PET全拉伸丝性能的影响

国际纺织导报 2021年第7期49卷 9-10页

作者： k.Pawar R.Turukmane 王增效(译) SVkM S NMIMS(印度) 不详

纺丝后处理工艺对纤维牵伸后的强度和伸长率有显著影响。在恒定温度下,牵伸速率的变化会对纤维拉伸力学行为产生不同影响。当牵伸速率较低时,聚合物在牵伸力的作用下有足够的时间进行松弛并表现出微形变行为。随着牵伸速率的增大,纤维... 详细信息

纺丝后处理工艺对纤维牵伸后的强度和伸长率有显著影响。在恒定温度下,牵伸速率的变化会对纤维拉伸力学行为产生不同影响。当牵伸速率较低时,聚合物在牵伸力的作用下有足够的时间进行松弛并表现出微形变行为。随着牵伸速率的增大,纤维产生细颈形变从而使材料得以继续牵伸。当牵伸速率非常高时,材料来不及产生松弛,累积的弹性应力会导致其产生脆性断裂。按照相关标准设置牵伸工艺参数,然后通过改变牵伸力对牵伸工艺进行优化,并检查其对聚酯长丝强度和伸长率的影响。结果显示,随着牵伸力的增大,纤维强度从1.85 cN/dtex增大到2.58 cN/dtex,纤维伸长率则逐渐降低。

关键词：聚酯(PET)纤维全拉伸丝(FDY) 纺丝牵伸

用石膏处理土壤和水减轻钠质水对黑绿豆的有害作用

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园艺与种苗 1992年第5期 55-55页

作者： k.R.Swamy 付波

检测地下水发现,在印度北海岸的安得拉普拉德斯的阿纳卡帕莱Etikoppaka、乔达瓦兰和马塞分别有44.70、22和26％的工厂区,水中残留的碳酸钠超过2.5毫克当量/升。在水中混合一些廉价的易溶解的钙,来降低钠钙比值,能够大大缓解灌溉水的有... 详细信息

检测地下水发现,在印度北海岸的安得拉普拉德斯的阿纳卡帕莱Etikoppaka、乔达瓦兰和马塞分别有44.70、22和26％的工厂区,水中残留的碳酸钠超过2.5毫克当量/升。在水中混合一些廉价的易溶解的钙,来降低钠钙比值,能够大大缓解灌溉水的有害作用(paliwal,1972)。由于石膏便宜且易溶解,可用

关键词：有害作用黑绿豆钠质茎秆籽粒石膏硫酸钙硫酸盐矿物毫克当量碳酸钠纯碱碳酸盐

用石膏处理土壤和水减轻钠质水对黑绿豆的有害作用

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国外农学（杂粮作物） 1992年第5期 55-55,45页

作者： k.R.Swamy 付波

检测地下水发现,在印度北海岸的安得拉普拉德斯的阿纳卡帕莱Etikoppaka、乔达瓦兰和马塞分别有44.70、22和26％的工厂区,水中残留的碳酸钠超过2.5毫克当量/升。在水中混合一些廉价的易溶解的钙,来降低钠钙比值,能够大大缓解灌溉水的有害作用(paliwal,1972)。

关键词：绿豆黑绿豆碳酸钠毒害