Ruthenium(Ru)-based chalcogenide(S,Se)is a promising material in various fields,such as optics,photoelectrodes,and electrocatalysis,owing to its suitable bandgap for generating charge carriers under light illumination...Ruthenium(Ru)-based chalcogenide(S,Se)is a promising material in various fields,such as optics,photoelectrodes,and electrocatalysis,owing to its suitable bandgap for generating charge carriers under light illumination ranging from visible to near-infrared(NIR)and its high absorption coefficient.In this study,we report the synthesis of Ru Se_(2)thin films by chemical vapor deposition(CVD)with a bandgap matching the NIR region at 0.52 e V.Further,we demonstrated Ru S_(2x)Se_(2-2x)alloy films using the post-sulfurization process after CVD Ru Se_(2)with a tunable bandgap from 0.52 to 1.39 e V depending on sulfur composition.Remarkably,Ru S_(2x)Se_(2-2x)alloy film metal–semiconductor–metal(MSM)photodetector sulfurized at 500°C,with a 0.75 e V bandgap,exhibits enhanced broad absorption across NIR spectral ranges,suppressed dark current and high photoresponsivity in NIR wavelengths range even at zero-bias.We believe the bandgaptunable Ru S_(2x)Se_(2-2x)thin film through an efficient deposition method could be suitable for various optoelectronic applications.展开更多
This paper presents the design and prototype of a small quadruped robot whose walking motion is realized by two piezocomposite actuators. In the design, biomimetic ideas are employed to obtain the agility of motions a...This paper presents the design and prototype of a small quadruped robot whose walking motion is realized by two piezocomposite actuators. In the design, biomimetic ideas are employed to obtain the agility of motions and sustainability of a heavy load. The design of the robot legs is inspired by the leg configuration of insects, two joints （hip and knee） of the leg enable two basic motions, lifting and stepping. The robot frame is designed to have a slope relative to the horizontal plane, which makes the robot move forward. In addition, the bounding locomotion of quadruped animals is implemented in the robot. Experiments show that the robot can carry an additional load of about 100 g and run with a fairly high velocity. The quadruped prototype can be an important step towards the goal of building an autonomous mobile robot actuated by piezocomposite actuators.展开更多
This paper presents the development of a mesoscale self-contained quadruped mobile robot that employs two pieces of piezocomposite actuators for the bounding locomotion.The design of the robot leg is inspired by legge...This paper presents the development of a mesoscale self-contained quadruped mobile robot that employs two pieces of piezocomposite actuators for the bounding locomotion.The design of the robot leg is inspired by legged insects and animals, and the biomimetic concept is implemented in the robot in a simplified form,such that each leg of the robot has only one degree of freedom.The lack of degree of freedom is compensated by a slope of the robot frame relative to the horizontal plane.For the implementation of the self-contained mobile robot,a small power supply circuit is designed and installed on the robot.Experimental results show that the robot can locomote at about 50 mm·s^(-1)with the circuit on board,which can be considered as a significant step toward the goal of building an autonomous legged robot actuated by piezoelectric actuators.展开更多
Supercooling storage reduces the temperature of a product by lowering its freezing point without phase transition and may extend its shelf life.However,it is difficult to maintain the supercooled state of food as it i...Supercooling storage reduces the temperature of a product by lowering its freezing point without phase transition and may extend its shelf life.However,it is difficult to maintain the supercooled state of food as it is thermodynamically metastable.A slow cooling rate and minimal fluctuation are essential for achieving stable supercooling storage.Therefore,a stepwise algorithm was adopted for supercooling storage in this study.Salmon and olive flounder were stored at 3℃(refrigeration),18℃(freezing),and2℃(supercooling)for 12 days.Samples were maintained in a supercooled state and unfrozen during the storage period.Samples stored after the supercooling treatment were superior with respect to drip loss and water holding capacity(WHC)compared to frozen samples,regardless of the type of sample.WHC and total volatile basic nitrogen values of olive flounder was higher than those in salmon owing to the higher water and protein content in olive flounder than in salmon.Moreover,the supercooled samples inhibited the increase in trimethylamine and volatile basic nitrogen levels.Microbial growth was slow.Thus,a stepwise algorithm for stable supercooled storage was achieved,which effectively preserved fish quality better than freezing and refrigeration storage.展开更多
基金supported by TANAKA KIKINZOKU KOGYO K.Kfinancially supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.NRF-2022R1A2C2006764)the Materials and Components Technology Development Program of MOTIE/KEIT(No.[20012460])。
文摘Ruthenium(Ru)-based chalcogenide(S,Se)is a promising material in various fields,such as optics,photoelectrodes,and electrocatalysis,owing to its suitable bandgap for generating charge carriers under light illumination ranging from visible to near-infrared(NIR)and its high absorption coefficient.In this study,we report the synthesis of Ru Se_(2)thin films by chemical vapor deposition(CVD)with a bandgap matching the NIR region at 0.52 e V.Further,we demonstrated Ru S_(2x)Se_(2-2x)alloy films using the post-sulfurization process after CVD Ru Se_(2)with a tunable bandgap from 0.52 to 1.39 e V depending on sulfur composition.Remarkably,Ru S_(2x)Se_(2-2x)alloy film metal–semiconductor–metal(MSM)photodetector sulfurized at 500°C,with a 0.75 e V bandgap,exhibits enhanced broad absorption across NIR spectral ranges,suppressed dark current and high photoresponsivity in NIR wavelengths range even at zero-bias.We believe the bandgaptunable Ru S_(2x)Se_(2-2x)thin film through an efficient deposition method could be suitable for various optoelectronic applications.
文摘This paper presents the design and prototype of a small quadruped robot whose walking motion is realized by two piezocomposite actuators. In the design, biomimetic ideas are employed to obtain the agility of motions and sustainability of a heavy load. The design of the robot legs is inspired by the leg configuration of insects, two joints （hip and knee） of the leg enable two basic motions, lifting and stepping. The robot frame is designed to have a slope relative to the horizontal plane, which makes the robot move forward. In addition, the bounding locomotion of quadruped animals is implemented in the robot. Experiments show that the robot can carry an additional load of about 100 g and run with a fairly high velocity. The quadruped prototype can be an important step towards the goal of building an autonomous mobile robot actuated by piezocomposite actuators.
基金supported by Korea Research Foundation grant(KRF-2006-005-J03303)and Seoul R&BD Program
文摘This paper presents the development of a mesoscale self-contained quadruped mobile robot that employs two pieces of piezocomposite actuators for the bounding locomotion.The design of the robot leg is inspired by legged insects and animals, and the biomimetic concept is implemented in the robot in a simplified form,such that each leg of the robot has only one degree of freedom.The lack of degree of freedom is compensated by a slope of the robot frame relative to the horizontal plane.For the implementation of the self-contained mobile robot,a small power supply circuit is designed and installed on the robot.Experimental results show that the robot can locomote at about 50 mm·s^(-1)with the circuit on board,which can be considered as a significant step toward the goal of building an autonomous legged robot actuated by piezoelectric actuators.
文摘Supercooling storage reduces the temperature of a product by lowering its freezing point without phase transition and may extend its shelf life.However,it is difficult to maintain the supercooled state of food as it is thermodynamically metastable.A slow cooling rate and minimal fluctuation are essential for achieving stable supercooling storage.Therefore,a stepwise algorithm was adopted for supercooling storage in this study.Salmon and olive flounder were stored at 3℃(refrigeration),18℃(freezing),and2℃(supercooling)for 12 days.Samples were maintained in a supercooled state and unfrozen during the storage period.Samples stored after the supercooling treatment were superior with respect to drip loss and water holding capacity(WHC)compared to frozen samples,regardless of the type of sample.WHC and total volatile basic nitrogen values of olive flounder was higher than those in salmon owing to the higher water and protein content in olive flounder than in salmon.Moreover,the supercooled samples inhibited the increase in trimethylamine and volatile basic nitrogen levels.Microbial growth was slow.Thus,a stepwise algorithm for stable supercooled storage was achieved,which effectively preserved fish quality better than freezing and refrigeration storage.
