The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-m...The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation.展开更多
A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow d...A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow detection times and low sensitivities.Here,we developed a rapid detection method for tracing waterborne pathogens by an innovative optofluidic platform,a plasmonic bacteria on a nanoporous mirror,that allows effective hydrodynamic cell trapping,enrichment of pathogens,and optical signal amplifications.We designed and simulated the integrated optofluidic platform to maximize the enrichment of the bacteria and to align bacteria on the nanopores and plasmonic mirror via hydrodynamic cell trapping.Gold nanoparticles are self-assembled to form antenna arrays on the surface of bacteria,such as Escherichia coli and Pseudomonas aeruginosa,by replacing citrate with hydroxylamine hydrochloride in order to amplify the signal of the plasmonic optical array.Owing to the synergistic contributions of focused light via the nanopore geometry,self-assembled nanoplasmonic optical antennas on the surface of bacteria,and plasmonic mirror,we obtain a sensitivity of detecting E.coli as low as 102 cells/ml via surface-enhanced Raman spectroscopy.We believe that our label-free strategy via an integrated optofluidic platform will pave the way for the rapid,precise identification of various pathogens.展开更多
This review is focused on carbon nanotube(CNT)-elastomeric polymer nanocom-posites,which have attracted industrial and academic interest over the years due to their enhanced properties.Major factors notably CNT type,s...This review is focused on carbon nanotube(CNT)-elastomeric polymer nanocom-posites,which have attracted industrial and academic interest over the years due to their enhanced properties.Major factors notably CNT type,surface modifica-tion,dispersion of CNT,and processing techniques that affect the physical properties of CNT-elastomeric polymer nanocomposites are reviewed,and several key physical properties,including tensile,electrical,and thermal properties,were also included in this review.Some of the key challenges that undermine the effectiveness of CNTs and their composites with elastomeric polymers,and the potential applications of CNT-elastomeric composites are also captured.展开更多
基金supported by the National Core Research Center Program from MOST and KOSEF (No.R15-2006-022-01001-0),Korea
文摘The study on damaged layer is necessary for improving the machinability in micro-machining because the damaged layer affects the micro mold life and micro machine parts. This study examined the ultra-precision micro-machining characteristics, such as cutting speed, feed rate and cutting depth, of a micro-damaged layer produced by an ultra-high speed air turbine spindle. The micro cutting force, surface roughness and plastic deformation layer were investigated according to the machining conditions. The damaged layer was measured using optical microscope on samples prepared through metallographic techniques. The scale of the damaged layer depends on the cutting process parameters, particularly, the feed per tooth and axial depth of the cut. According to the experimental results, the depth of the damaged layer is increased by increasing the feed per tooth and cutting depth, also the damaged layer occurs less in down-milling compared with up-milling during the micro-machining operation.
基金supported by the Air Force Office of Scientific Research Grants AFOSR FA2386-13-1-4120by the International Research and Development Program of the National Research Foundation of Korea(NRF)+5 种基金by the Ministry of Science,ICT,and Future Planning(MSIP)(no.2016K1A3A1A32913356)by the Mid-Career Researcher Support Program of NRF by the MSIP(no.2016R1A2B3014157)by the Basic Science Research Program through the NRF funded by the Ministry of Education(no.2016R1A6A1A03012845)by the C1 Gas Refinery Program of NRF by the MSIP(no.2016M3D3A1A01913546)by the Leading Foreign Research Institute Recruitment Program through NRF by the MSIP(no.2013K1A4A3055268)by the National Institutes of Health(NIH)(R01 AI117064-01).
文摘A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow detection times and low sensitivities.Here,we developed a rapid detection method for tracing waterborne pathogens by an innovative optofluidic platform,a plasmonic bacteria on a nanoporous mirror,that allows effective hydrodynamic cell trapping,enrichment of pathogens,and optical signal amplifications.We designed and simulated the integrated optofluidic platform to maximize the enrichment of the bacteria and to align bacteria on the nanopores and plasmonic mirror via hydrodynamic cell trapping.Gold nanoparticles are self-assembled to form antenna arrays on the surface of bacteria,such as Escherichia coli and Pseudomonas aeruginosa,by replacing citrate with hydroxylamine hydrochloride in order to amplify the signal of the plasmonic optical array.Owing to the synergistic contributions of focused light via the nanopore geometry,self-assembled nanoplasmonic optical antennas on the surface of bacteria,and plasmonic mirror,we obtain a sensitivity of detecting E.coli as low as 102 cells/ml via surface-enhanced Raman spectroscopy.We believe that our label-free strategy via an integrated optofluidic platform will pave the way for the rapid,precise identification of various pathogens.
基金This work was supported by both the BK 21 Plus and the research fund[grant number 20135010300700]from Korea Institute of Energy Technology Evaluation and Planning(KETEP).
文摘This review is focused on carbon nanotube(CNT)-elastomeric polymer nanocom-posites,which have attracted industrial and academic interest over the years due to their enhanced properties.Major factors notably CNT type,surface modifica-tion,dispersion of CNT,and processing techniques that affect the physical properties of CNT-elastomeric polymer nanocomposites are reviewed,and several key physical properties,including tensile,electrical,and thermal properties,were also included in this review.Some of the key challenges that undermine the effectiveness of CNTs and their composites with elastomeric polymers,and the potential applications of CNT-elastomeric composites are also captured.
