Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to a...Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys.In this study,the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography(micro XCT)and a standard leak test.The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance.Instead,micro XCT shows distinct advantages by enabling more comprehensive analysis.It reveals the presence of a low atomic number impregnates sealant within casting defects,which has low grey contrast and allows for visualizing primary leakage paths in 3D.The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT.This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals.展开更多
Agroforestry can leverage the co-benefits of climate change adaptation and mitigation while conserving biodiversity and restoring degraded and deforested lands.The preference of relevant stakeholders regarding agrofor...Agroforestry can leverage the co-benefits of climate change adaptation and mitigation while conserving biodiversity and restoring degraded and deforested lands.The preference of relevant stakeholders regarding agroforestry practices enhances sustainable land management through strategic decision-making in Seychelles and other island states.A suitable approach for assessing stakeholders'preferences of agroforestry is the implementation of the strengths,weaknesses,opportunities,and threats(SWOT)approach in combination with the analytic hierarchy process(AHP)method.The entry point of this study is an extensive literature review process,during which 28 SWOT factors were identified.These SWOT factors were deliberated on during a half-day workshop with agricultural experts who agreed on 20 SWOT factors that reflect the local realities of the Seychelles through a consensus approach.Using the SWOT-AHP approach,focus group discussions were conducted to examine the perceptions of researchers and extension workers about the adoption of agroforestry in Seychelles.The results indicated that the positive aspects of smallholder agroforestry outweigh the negative aspects.For example,increased agricultural production,control runoff and soil erosion receive the highest scores among the strength factors perceived by researchers and extension workers,respectively.The willingness of international organizations to fund agroforestry-related projects and the existence of native tree species on farmlands have the highest scores among the opportunity factors.The lack of education,information,and communication between the government and farmers,and the small land size and crop competition have the highest scores among the weakness factors.Lastly,change in government policies on land use has the highest score among the threat factors by researchers,whereas the most significant threat is climate change and variability for the extension workers.The provision for a 30-year land lease agreement in the National Agroforestry Policy of Seychelles is viewed by both groups as an incentive that could potentially drive the adoption and acceptability of agroforestry.Furthermore,better coordination of various efforts to promote agroforestry and more substantial extension services for farmers,especially the role of technologies for optimal production on small plots of land,can enhance climate resilience in Seychelles and other small island developing states.展开更多
文摘Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys.In this study,the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography(micro XCT)and a standard leak test.The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance.Instead,micro XCT shows distinct advantages by enabling more comprehensive analysis.It reveals the presence of a low atomic number impregnates sealant within casting defects,which has low grey contrast and allows for visualizing primary leakage paths in 3D.The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT.This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals.
基金The United Nations Development Programme(UNDP)Small Grants Program supported this work through the project“Exploring Innovative Opportunities for Promoting Synergies between Climate Change Adaptation and Mitigation in Seychelles”(SEY/SGP/OP6/Y5/CORE/YCC/2019/25),under the youth and climate change portfolio implemented by the University of Seychelles。
文摘Agroforestry can leverage the co-benefits of climate change adaptation and mitigation while conserving biodiversity and restoring degraded and deforested lands.The preference of relevant stakeholders regarding agroforestry practices enhances sustainable land management through strategic decision-making in Seychelles and other island states.A suitable approach for assessing stakeholders'preferences of agroforestry is the implementation of the strengths,weaknesses,opportunities,and threats(SWOT)approach in combination with the analytic hierarchy process(AHP)method.The entry point of this study is an extensive literature review process,during which 28 SWOT factors were identified.These SWOT factors were deliberated on during a half-day workshop with agricultural experts who agreed on 20 SWOT factors that reflect the local realities of the Seychelles through a consensus approach.Using the SWOT-AHP approach,focus group discussions were conducted to examine the perceptions of researchers and extension workers about the adoption of agroforestry in Seychelles.The results indicated that the positive aspects of smallholder agroforestry outweigh the negative aspects.For example,increased agricultural production,control runoff and soil erosion receive the highest scores among the strength factors perceived by researchers and extension workers,respectively.The willingness of international organizations to fund agroforestry-related projects and the existence of native tree species on farmlands have the highest scores among the opportunity factors.The lack of education,information,and communication between the government and farmers,and the small land size and crop competition have the highest scores among the weakness factors.Lastly,change in government policies on land use has the highest score among the threat factors by researchers,whereas the most significant threat is climate change and variability for the extension workers.The provision for a 30-year land lease agreement in the National Agroforestry Policy of Seychelles is viewed by both groups as an incentive that could potentially drive the adoption and acceptability of agroforestry.Furthermore,better coordination of various efforts to promote agroforestry and more substantial extension services for farmers,especially the role of technologies for optimal production on small plots of land,can enhance climate resilience in Seychelles and other small island developing states.
