Beyond the traditional focus on improvements in mechanical, electronic and absorption properties, controllability, actuation, and dynamic response of monoliths have received increasing attentions for practical applica...Beyond the traditional focus on improvements in mechanical, electronic and absorption properties, controllability, actuation, and dynamic response of monoliths have received increasing attentions for practical applications. However, most of them could only realize simple response to constant conditions(e.g. a stationary magnetic field) while carrying out humdrum motions. By controlling distribution of metal organic framework obtained carbon-enriched Fe304 nanoparticles in self-assembly reduced graphene oxide(RGO) monoliths, we could achieve two distinctive RGO-Fe_3 O_4 stirrers that could dynamically respond to the rapidly changing magnetic field while executing designed movements precisely: rotating with lying down posture or standing straight posture. These stirrers can not only be applied in environmental remediation(e.g.suction skimmer), but also be recycled as electrode active materials for supercapacitors after fulfilling their destiny, realizing transformation of trash to treasure, which will inspire other dynamically responsive monoliths for various applications.展开更多
Die filling is a critical stage during powder compaction,which can significantly affect the product quality and efficiency.In this paper,a forced feeder is introduced attempting to improve the filling performance of a...Die filling is a critical stage during powder compaction,which can significantly affect the product quality and efficiency.In this paper,a forced feeder is introduced attempting to improve the filling performance of a lab-scale die filling system.The die filling process is analysed with a graphics processing units(GPU)enhanced discrete element method(DEM).Various stirrer designs are assessed for a wide range of process settings(i.e.,stirrer speed,filling speed)to explore their influence on the die filling performance of free-flowing powder.Numerical results show that die filing with the novel helical-ribbon(i.e.,type D)stirrer design exhibits the highest filling ratio,implying that it is the most robust stirrer design for the feeder configuration considered.Furthermore,die filling performance with the type D stirrer design is a function of the stirrer speed and the filling speed.A positive variation of filling ratio(ηf>0%)can be ensured over the whole range of filling speed by adjusting the stirrer speed(i.e.,increasing the stirrer speed).The approach used in this study can not only help understand how the stirrer design affects the die filling performance but also guide the optimization of feeder system and process settings.展开更多
基金supported by Natural Science Foundation of SZU (Grant No. 2017004)Early Career Scheme of the Research Grants Council of Hong Kong SAR, China, under the Project No. CityU 109213a Grant from the City University of Hong Kong (9610372)
文摘Beyond the traditional focus on improvements in mechanical, electronic and absorption properties, controllability, actuation, and dynamic response of monoliths have received increasing attentions for practical applications. However, most of them could only realize simple response to constant conditions(e.g. a stationary magnetic field) while carrying out humdrum motions. By controlling distribution of metal organic framework obtained carbon-enriched Fe304 nanoparticles in self-assembly reduced graphene oxide(RGO) monoliths, we could achieve two distinctive RGO-Fe_3 O_4 stirrers that could dynamically respond to the rapidly changing magnetic field while executing designed movements precisely: rotating with lying down posture or standing straight posture. These stirrers can not only be applied in environmental remediation(e.g.suction skimmer), but also be recycled as electrode active materials for supercapacitors after fulfilling their destiny, realizing transformation of trash to treasure, which will inspire other dynamically responsive monoliths for various applications.
基金Projects(52175373,52005108,52275096)supported by the National Natural Science Foundation of ChinaProject(2018YFA0702800)supported by the National Key Research and Development Program of ChinaProject(2022HZ024005)supported by the Fujian Provincial Major Research Project,China。
基金the financial support from Genentech Ltd.,the Engineering and Physical Science Research Council(Grant No.EP/M02976X)the Marie Skłodowska-Curie Individual Fellowships under European Union's Horizon 2020 research and innovation programme(Grant No.840264)。
文摘Die filling is a critical stage during powder compaction,which can significantly affect the product quality and efficiency.In this paper,a forced feeder is introduced attempting to improve the filling performance of a lab-scale die filling system.The die filling process is analysed with a graphics processing units(GPU)enhanced discrete element method(DEM).Various stirrer designs are assessed for a wide range of process settings(i.e.,stirrer speed,filling speed)to explore their influence on the die filling performance of free-flowing powder.Numerical results show that die filing with the novel helical-ribbon(i.e.,type D)stirrer design exhibits the highest filling ratio,implying that it is the most robust stirrer design for the feeder configuration considered.Furthermore,die filling performance with the type D stirrer design is a function of the stirrer speed and the filling speed.A positive variation of filling ratio(ηf>0%)can be ensured over the whole range of filling speed by adjusting the stirrer speed(i.e.,increasing the stirrer speed).The approach used in this study can not only help understand how the stirrer design affects the die filling performance but also guide the optimization of feeder system and process settings.
