The present study reported the effect of filler metals on the microstructure and mechanical properties of pulsed current gas tungsten arc-welded Inconel 718 plates. Two different filler metals such as ERNiCr-3 and ERN...The present study reported the effect of filler metals on the microstructure and mechanical properties of pulsed current gas tungsten arc-welded Inconel 718 plates. Two different filler metals such as ERNiCr-3 and ERNiCrMo-4 were employed for welding Inconel 718. The primary objective of this study is to suppress or eradicate the deleterious phase such as Laves or δ （delta） which is considered to be detrimental to the weld properties. Microstructure examination corroborated the presence of unmixed zone at the HAZ for both the weldments. Tensile test trials envisaged that ERNiCrMo-4 weldments offered better tensile properties compared to ERNiCr-3 weldments, whereas the impact toughness was found to be better for ERNiCr-3 weldments. Line mapping analysis was carried out to study the elemental migration across the weldments. The structure-property relationships of the weldments were arrived at using the combined tech- niques of optical and scanning electron microscopy. Optical and SEM/EDAX analysis showed that there is no prominent occurrence of deleterious phases at the weld zone on employing these filler metals.展开更多
Soil erosion affects land qualities and water resources.This problem is severe in Ethiopia due to its topographic features.The present research was aimed to estimate spatiotemporal changes in land-use/land-cover patte...Soil erosion affects land qualities and water resources.This problem is severe in Ethiopia due to its topographic features.The present research was aimed to estimate spatiotemporal changes in land-use/land-cover pattern and soil erosion in the Yezat watershed in Ethiopia.This study was carried out by using landsat imageries of 2001,2010 and 2015.Ilmages were classified into categories using supervised classification by maximum likelihood algorithm.They were also classified into different biomass levels by using Normalized Difference Vegetation Index(NDVI)analysis.Revised Universal Soil Loss Equation modeling was applied in a GIS environment to quantify the potential soil erosion risk.The area under grassland,woodland and homesteads have increased by 610.69(4%),101.69(0.67%)and 126.6 ha(0.83%)during 2001-2015.The extent of cultivated land and shrub/bushland was reduced by 323.43(0.02%)and 515.44 ha(3.41%),respectively,during the same period.The vegetation cover in the watershed decreased by 91% during 2001-2010,and increased by 88% during 2010-2015.Increase of NDVI values indicates better ground cover due to implementation of integrated watershed development program in the region.The estimated annual soil losses were 7.2 t ha^(-1) yr^(-1) in 2001,7.7t ha^(-1) yr^(-1) in 2010 and 4.8t ha^(-1) yr^(-1) in 2015.Management interventions are necessary to improve the status and utilization of watershed resources in response to sustainable land management practices for sustainable livelihood of the local people.展开更多
基金sincerely acknowledge Aeronautical Research & Development Board (AR & DB), Govt. of India for funding this project
文摘The present study reported the effect of filler metals on the microstructure and mechanical properties of pulsed current gas tungsten arc-welded Inconel 718 plates. Two different filler metals such as ERNiCr-3 and ERNiCrMo-4 were employed for welding Inconel 718. The primary objective of this study is to suppress or eradicate the deleterious phase such as Laves or δ （delta） which is considered to be detrimental to the weld properties. Microstructure examination corroborated the presence of unmixed zone at the HAZ for both the weldments. Tensile test trials envisaged that ERNiCrMo-4 weldments offered better tensile properties compared to ERNiCr-3 weldments, whereas the impact toughness was found to be better for ERNiCr-3 weldments. Line mapping analysis was carried out to study the elemental migration across the weldments. The structure-property relationships of the weldments were arrived at using the combined tech- niques of optical and scanning electron microscopy. Optical and SEM/EDAX analysis showed that there is no prominent occurrence of deleterious phases at the weld zone on employing these filler metals.
文摘Soil erosion affects land qualities and water resources.This problem is severe in Ethiopia due to its topographic features.The present research was aimed to estimate spatiotemporal changes in land-use/land-cover pattern and soil erosion in the Yezat watershed in Ethiopia.This study was carried out by using landsat imageries of 2001,2010 and 2015.Ilmages were classified into categories using supervised classification by maximum likelihood algorithm.They were also classified into different biomass levels by using Normalized Difference Vegetation Index(NDVI)analysis.Revised Universal Soil Loss Equation modeling was applied in a GIS environment to quantify the potential soil erosion risk.The area under grassland,woodland and homesteads have increased by 610.69(4%),101.69(0.67%)and 126.6 ha(0.83%)during 2001-2015.The extent of cultivated land and shrub/bushland was reduced by 323.43(0.02%)and 515.44 ha(3.41%),respectively,during the same period.The vegetation cover in the watershed decreased by 91% during 2001-2010,and increased by 88% during 2010-2015.Increase of NDVI values indicates better ground cover due to implementation of integrated watershed development program in the region.The estimated annual soil losses were 7.2 t ha^(-1) yr^(-1) in 2001,7.7t ha^(-1) yr^(-1) in 2010 and 4.8t ha^(-1) yr^(-1) in 2015.Management interventions are necessary to improve the status and utilization of watershed resources in response to sustainable land management practices for sustainable livelihood of the local people.
