Classification of 3D bioprinting As we mentioned in the last editorial,3D printing,also known as additive manufacturing,could be considered as the reverse process of potato cutting,automatically assembling sliced pota...Classification of 3D bioprinting As we mentioned in the last editorial,3D printing,also known as additive manufacturing,could be considered as the reverse process of potato cutting,automatically assembling sliced potato,shredded potato,diced potato to integrity[1].Generally speaking,cell-laden 3D bioprinting can be classified into three types:extrusion-based,droplet-based and photocuring-based bioprinting according to different printing principles.Extrusion-based bioprinting squeezes out continuous hydrogel fibers to set up structures;dropletbased bioprinting generates droplets as the basic unit for biofabrication;and photocuring-based bioprinting utilizes the characteristics of light-sensitive materials,to stack 3D models layer-by-layer.Different bioprinting approaches own diverse characteristics facing various scenarios and have specific requirements for bioinks.展开更多
Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little i...Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D printers.In this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were tested.The experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed HIPS.The prediction models of the process parameters were regressed to produce the optimal combination of process parameters.The experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile strength.With an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer thickness.In addition,they all increased with an increase of infill density.It was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were optimal.Our results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.展开更多
Visualization experiments were conducted to clarify the operational characteristics of a polymer pulsating heat pipe(PHP).Hydrofluoroether(HFE)-7100 was used as a working fluid,and its filling ratio was 50%of the enti...Visualization experiments were conducted to clarify the operational characteristics of a polymer pulsating heat pipe(PHP).Hydrofluoroether(HFE)-7100 was used as a working fluid,and its filling ratio was 50%of the entire PHP channel.A semi-transparent PHP was fabricated using a transparent polycarbonate sheet and a plastic 3D printer,and the movements of liquid slugs and vapor plugs of the working fluid were captured with a high-speed camera.The video images were then analyzed to obtain the flow patterns in the PHP.The heat transfer characteristics of the PHPwere discussed based on the flowpatterns and temperature distributions obtainedwith thermocouples.Before starting heating,because of high wettability,large liquid slugs positioned at the evaporator section of the PHP.After starting heating,since the occurrence of boiling divided the large liquid slugs,oscillatory flowof smaller liquid slugs and vapor plugs was found in the PHP.Clear circulation flow of liquid slugs and vapor plugs was observed when the power input to the PHP was larger than 12.0 W.The flow patterns and temperature distributions confirmed that the circulation flow enhanced the heat transfer from the evaporator section to the condenser section of the PHP.In the circulation flow mode,large growth and contraction of vapor plugs were found one after another in all even-numbered PHP channels.However,the analysis of flow patterns clarified that the phase-change heat transfer rate by large growth and contraction of vapor plugs was 19%of the total heat transfer rate of the PHP.Although the generation of large vapor plugs was found in the PHP,most of the heat was transferred by the sensible heat of the working fluid.展开更多
Recently,a China-Asia transit train,loaded with second-hand cars,auto parts,and electronic products,set off slowly from the China-Kazakhstan Logistics Base in Lianyungang,heading to stations such as Almaty in Central ...Recently,a China-Asia transit train,loaded with second-hand cars,auto parts,and electronic products,set off slowly from the China-Kazakhstan Logistics Base in Lianyungang,heading to stations such as Almaty in Central Asia,and to more distant European stations.This express marks the 410th China-Europe(Central Asia)train launched from Lianyungang this year,indicating that the first half target had been completed 25 days in advance.Public data shows that the annual transportation value of the China-E.U.Railway Express has increased from USD 8 billion in 2016 to USD 56.7 billion in 2023.Export goods have gradually expanded from initial IT products such as laptops and printers to more than 50,000 categories including clothing,shoes,hats,auto parts,daily necessities,food,wood,furniture,chemical products,and machinery equipment.展开更多
A submergible robot model has been presented, and for 3D printing measures, their parts have been modified enough. It has been shown in our design that using printable connectors—a few engines and weight arrangements...A submergible robot model has been presented, and for 3D printing measures, their parts have been modified enough. It has been shown in our design that using printable connectors—a few engines and weight arrangements can be carried out, permitting distinctive moving prospects. After presenting our configuration and delineating a bunch of potential structures, a helpful model dependent on open-source equipment and programming arrangements has been presented conditionally. The model can be effectively tried in a few makes-a plunge streams and lakes throughout the planet. The unwavering quality of the printed models can be strained distinctly in generally shallow waters. Nonetheless, we accept that their accessibility will inspire the overall population to construct and test submerged robots, subsequently accelerating the improvement of imaginative arrangements and applications.展开更多
The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model par...The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model parts. The model parts were 3D printed using FDM technology and the ZMorph 2.0 hybrid 3D printer. The accuracy of 3D printing of the model part influences the realization of modular devices. In recent years, technology has evolved a lot, and the need to have the most efficient manufacturing equipment has increased. This is the reason for the development of 3D printers using FDM technology for plastic parts. The software used by these 3D printers used in FDM technology is very sophisticated, as they allow the manufacture of very precise 3D prototypes, identical to the designed 3D model, through modern additive manufacturing techniques. The quality and mechanical strength of the prototypes obtained using 3D printers is very good. The materials used by the 3D printers manufactured by FDM are cheap and accessible. These 3D printers are used to make three-dimensional objects (gears, flanges, bearings, covers, casings, mechanisms, figurines, interior and exterior design elements, architectural models, medical models).展开更多
This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop ...This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop a long short-term memory(LSTM)network capable of assessing this impact.We conducted an extensive analysis involving 12 distinct infill patterns,collecting time-series data to examine their effects on the acceleration of the printer’s bed.The LSTM network was trained using acceleration data from the adaptive cubic infill pattern,while the Archimedean chords infill pattern provided data for evaluating the network’s prediction accuracy.This involved utilizing offline time-series acceleration data as the training and testing datasets for the LSTM model.Specifically,the LSTM model was devised to predict the acceleration of a fused deposition modeling(FDM)printer using data from the adaptive cubic infill pattern.Rigorous testing yielded a root mean square error(RMSE)of 0.007144,reflecting the model’s precision.Further refinement and testing of the LSTM model were conducted using acceleration data from the Archimedean chords infill pattern,resulting in an RMSE of 0.007328.Notably,the developed LSTM model demonstrated superior performance compared to an optimized recurrent neural network(RNN)in predicting machine acceleration data.The empirical findings highlight that the adaptive cubic infill pattern considerably influences the dimensional accuracy of parts printed using FDM technology.展开更多
In recent years proof of “indoor air quality”, designed to protect and improve the health and safety of workers, was a central strategy in the prevention of many companies. The man creates with the environment in wh...In recent years proof of “indoor air quality”, designed to protect and improve the health and safety of workers, was a central strategy in the prevention of many companies. The man creates with the environment in which he lives and works a continuous gas exchange through breathing;this makes the respiratory system main entrance of air pollutants. The indoor pollutants are numerous and originate from different sources. Their concentration may vary over time and depends on the nature of the source, on ventilation, habits and activities carried out by the occupants in the areas concerned. It is well known that photocopiers and laser printers are equipment that emit several chemicals (ozone, solvents, toner dust) both to release the materials used for their operation (toner, ink, paper) and then to the special printing technology used. During the printing and photocopying processes occurring chemical and physical processes complex, during which the components of toner and paper will react under the influence of light and high temperatures. More recently, there have been a growing number of articles as a result of indoor air pollution. They have become more and more significant;probably because of increasing of the concentrations of harmful substances in the confined environment. Particular attention has been given to the emission of harmful substances from electronic equipment and printing that are increasingly present in living and working place. This work was the main objective the emission of volatile organic compounds, formaldehyde and ozone from laser printing devices and consequently the estimation of elimination of same substances through a paper filters which operate through a mechanism of filtration surface with interstitial and penetration of particles into matrix filter on agglomeration, they also enclose type sandwich a layer of activated carbon.展开更多
文摘Classification of 3D bioprinting As we mentioned in the last editorial,3D printing,also known as additive manufacturing,could be considered as the reverse process of potato cutting,automatically assembling sliced potato,shredded potato,diced potato to integrity[1].Generally speaking,cell-laden 3D bioprinting can be classified into three types:extrusion-based,droplet-based and photocuring-based bioprinting according to different printing principles.Extrusion-based bioprinting squeezes out continuous hydrogel fibers to set up structures;dropletbased bioprinting generates droplets as the basic unit for biofabrication;and photocuring-based bioprinting utilizes the characteristics of light-sensitive materials,to stack 3D models layer-by-layer.Different bioprinting approaches own diverse characteristics facing various scenarios and have specific requirements for bioinks.
基金supported by the National Natural Science Foundation of China(Grant No.51975097)the National Key Research and Development Project(Grant No.2020YFA0713702).
文摘Recently,low-cost desktop three-dimensional(3D)printers,employing the fused deposition modeling(FDM)technique,have gained widespread popularity.However,most users cannot test the strength of printed parts,and little information is available about the mechanical properties of printed high-impact polystyrene(HIPS)parts using desktop 3D printers.In this study,the user-adjustable parameters of desktop 3D printers,such as crisscross raster orientation,layer thickness,and infill density,were tested.The experimental plans were designed using the Box-Behnken method,and tensile,3-point bending,and compression tests were carried out to determine the mechanical responses of the printed HIPS.The prediction models of the process parameters were regressed to produce the optimal combination of process parameters.The experimental results showcase that the crisscross raster orientation has significant effects on the flexural and compression strengths,but not on the tensile strength.With an increase in the layer thickness,the tensile,flexural,and compression strengths first decreased and then increased,reaching their minimum values at approximately 0.16 mm layer thickness.In addition,they all increased with an increase of infill density.It was demonstrated that when the raster orientation,layer thickness,and infill density were 13.08°/–76.92°,0.09 mm,and 80%,respectively,the comprehensive mechanical properties of the printed HIPS were optimal.Our results can help end-users of desktop 3D printers understand the effects of process parameters on the mechanical properties,and offer practical suggestions for setting proper printing parameters for fabricating HIPS parts.
基金supported by JSPS KAKENHI Grant Number 22K03947.
文摘Visualization experiments were conducted to clarify the operational characteristics of a polymer pulsating heat pipe(PHP).Hydrofluoroether(HFE)-7100 was used as a working fluid,and its filling ratio was 50%of the entire PHP channel.A semi-transparent PHP was fabricated using a transparent polycarbonate sheet and a plastic 3D printer,and the movements of liquid slugs and vapor plugs of the working fluid were captured with a high-speed camera.The video images were then analyzed to obtain the flow patterns in the PHP.The heat transfer characteristics of the PHPwere discussed based on the flowpatterns and temperature distributions obtainedwith thermocouples.Before starting heating,because of high wettability,large liquid slugs positioned at the evaporator section of the PHP.After starting heating,since the occurrence of boiling divided the large liquid slugs,oscillatory flowof smaller liquid slugs and vapor plugs was found in the PHP.Clear circulation flow of liquid slugs and vapor plugs was observed when the power input to the PHP was larger than 12.0 W.The flow patterns and temperature distributions confirmed that the circulation flow enhanced the heat transfer from the evaporator section to the condenser section of the PHP.In the circulation flow mode,large growth and contraction of vapor plugs were found one after another in all even-numbered PHP channels.However,the analysis of flow patterns clarified that the phase-change heat transfer rate by large growth and contraction of vapor plugs was 19%of the total heat transfer rate of the PHP.Although the generation of large vapor plugs was found in the PHP,most of the heat was transferred by the sensible heat of the working fluid.
文摘Recently,a China-Asia transit train,loaded with second-hand cars,auto parts,and electronic products,set off slowly from the China-Kazakhstan Logistics Base in Lianyungang,heading to stations such as Almaty in Central Asia,and to more distant European stations.This express marks the 410th China-Europe(Central Asia)train launched from Lianyungang this year,indicating that the first half target had been completed 25 days in advance.Public data shows that the annual transportation value of the China-E.U.Railway Express has increased from USD 8 billion in 2016 to USD 56.7 billion in 2023.Export goods have gradually expanded from initial IT products such as laptops and printers to more than 50,000 categories including clothing,shoes,hats,auto parts,daily necessities,food,wood,furniture,chemical products,and machinery equipment.
文摘A submergible robot model has been presented, and for 3D printing measures, their parts have been modified enough. It has been shown in our design that using printable connectors—a few engines and weight arrangements can be carried out, permitting distinctive moving prospects. After presenting our configuration and delineating a bunch of potential structures, a helpful model dependent on open-source equipment and programming arrangements has been presented conditionally. The model can be effectively tried in a few makes-a plunge streams and lakes throughout the planet. The unwavering quality of the printed models can be strained distinctly in generally shallow waters. Nonetheless, we accept that their accessibility will inspire the overall population to construct and test submerged robots, subsequently accelerating the improvement of imaginative arrangements and applications.
文摘The objective of the work is to determine the influence of the PLA melting temperature during 3D printing on the dimensional accuracy of the model parts. Two modular drilling devices were also made using PLA model parts. The model parts were 3D printed using FDM technology and the ZMorph 2.0 hybrid 3D printer. The accuracy of 3D printing of the model part influences the realization of modular devices. In recent years, technology has evolved a lot, and the need to have the most efficient manufacturing equipment has increased. This is the reason for the development of 3D printers using FDM technology for plastic parts. The software used by these 3D printers used in FDM technology is very sophisticated, as they allow the manufacture of very precise 3D prototypes, identical to the designed 3D model, through modern additive manufacturing techniques. The quality and mechanical strength of the prototypes obtained using 3D printers is very good. The materials used by the 3D printers manufactured by FDM are cheap and accessible. These 3D printers are used to make three-dimensional objects (gears, flanges, bearings, covers, casings, mechanisms, figurines, interior and exterior design elements, architectural models, medical models).
文摘This study explores the influence of infill patterns on machine acceleration prediction in the realm of three-dimensional(3D)printing,particularly focusing on extrusion technology.Our primary objective was to develop a long short-term memory(LSTM)network capable of assessing this impact.We conducted an extensive analysis involving 12 distinct infill patterns,collecting time-series data to examine their effects on the acceleration of the printer’s bed.The LSTM network was trained using acceleration data from the adaptive cubic infill pattern,while the Archimedean chords infill pattern provided data for evaluating the network’s prediction accuracy.This involved utilizing offline time-series acceleration data as the training and testing datasets for the LSTM model.Specifically,the LSTM model was devised to predict the acceleration of a fused deposition modeling(FDM)printer using data from the adaptive cubic infill pattern.Rigorous testing yielded a root mean square error(RMSE)of 0.007144,reflecting the model’s precision.Further refinement and testing of the LSTM model were conducted using acceleration data from the Archimedean chords infill pattern,resulting in an RMSE of 0.007328.Notably,the developed LSTM model demonstrated superior performance compared to an optimized recurrent neural network(RNN)in predicting machine acceleration data.The empirical findings highlight that the adaptive cubic infill pattern considerably influences the dimensional accuracy of parts printed using FDM technology.
文摘In recent years proof of “indoor air quality”, designed to protect and improve the health and safety of workers, was a central strategy in the prevention of many companies. The man creates with the environment in which he lives and works a continuous gas exchange through breathing;this makes the respiratory system main entrance of air pollutants. The indoor pollutants are numerous and originate from different sources. Their concentration may vary over time and depends on the nature of the source, on ventilation, habits and activities carried out by the occupants in the areas concerned. It is well known that photocopiers and laser printers are equipment that emit several chemicals (ozone, solvents, toner dust) both to release the materials used for their operation (toner, ink, paper) and then to the special printing technology used. During the printing and photocopying processes occurring chemical and physical processes complex, during which the components of toner and paper will react under the influence of light and high temperatures. More recently, there have been a growing number of articles as a result of indoor air pollution. They have become more and more significant;probably because of increasing of the concentrations of harmful substances in the confined environment. Particular attention has been given to the emission of harmful substances from electronic equipment and printing that are increasingly present in living and working place. This work was the main objective the emission of volatile organic compounds, formaldehyde and ozone from laser printing devices and consequently the estimation of elimination of same substances through a paper filters which operate through a mechanism of filtration surface with interstitial and penetration of particles into matrix filter on agglomeration, they also enclose type sandwich a layer of activated carbon.
