Ibaraki University , Japan, is a national university located in Ibaraki Prefecture, with campuses in the cities of Mito, Ami and Hitachi. It was established on May 31, 1949, integrating these prewar institutions: Mito High School , Ibaraki Normal School , Ibaraki Juvenile Normal School , and Taga Technical Specialists' College . The initial colleges were the College of Arts and science, the College of Education, and the College of Engineering. Wikipedia.
News Article | April 17, 2017
Many young stars, as well as more middle-aged stars like our sun, have "debris disks"--like the Oort Cloud in our own solar system--that are believed to be remnants of the system's formation. Recently, radio observations have detected gas within a number of such discs, but it was not clear why the gas was there. There are two major hypotheses: either the gas is primordial gas from the original gas cloud that formed the star, or it originates from collisions between objects in the disk. In search of a solution to this problem, a team from the RIKEN Star and Planet Formation Laboratory decided to look at emissions of carbon, which are important as they can provide clues to the origin of the gas. Normally, carbon will exist mostly in a molecular form, as carbon monoxide. Ultraviolet light from the central star will "dissociate" the atoms, creating free atomic carbon, but normally a chemical reaction--mediated by hydrogen--recombines the carbon into CO. However, if there is no hydrogen, then the reaction does not take place and the carbon remains in its atomic state. Aya Higuchi, the first author of the paper, published in Astrophysical Journal Letters, was able to use the ten-meter Atacama Submillimeter Telescope Experiment (ASTE) in Chile to examine the atomic carbon line from two young star systems--49 Ceti and Beta Pictoris--that are known to have debris disks. They then compared this from data on CO taken by the Atacama Large Millimeter/submillimeter Array (ALMA), an array of telescopes in the same facility. "We were surprised," she says, "to find atomic carbon in the disk, the first time this observation has been made at sub-millimeter wavelength. But more so, we were surprised at how much there was. It was about as common as the carbon monoxide." The implication, at least for these two star systems, is that there is very little hydrogen to drive the carbon back into CO. Because hydrogen makes up most of the gas in protoplanetary clouds, this hints that the gas is not primordial, but rather is generated from some process taking place in the debris disk. Gas has been found in other debris disks, but is not found in all. Higuchi says, "If we can perform similar measurements on other young stars, it will help to clarify the origin of the gas in debris disk. Our data here suggests that the gas is secondary." Looking to the future, she continues, "This work will also help to understand how a protoplanetary disk evolves into a debris disks by distinguishing the origin of the gas in the disks." The work was done in collaboration with scientists from Ibaraki University and Nagoya University.
Ibaraki University | Date: 2017-07-05
[Problem] To achieve transmission power characteristics and a power extinction ratio in a terahertz wave band that cannot be achieved conventionally. [Solution to problem] A cutout 20b is formed between one end and an opposite end of a rectangular metal thin plate to form a plurality of grid plates 20 each having an elongated grid part 20a between the one end and the opposite end. The grid plates 20 are stacked in such a manner that the grid parts 20a of the grid plates 20 are spaced at a given interval and face each other, thereby forming a grid plate stack 2a In this case, spacers 21 are inserted between one ends and between opposite ends of adjacent ones of the grid plates 20 to form parallel flat plates configured by the grid parts 20a. The grid plate stack 2a forming the parallel flat plates operates as a polarizer for a terahertz wave band.
Ibaraki University | Date: 2015-08-21
A wire grid device having transmission power characteristics and a power extinction ratio in a terahertz wave band that cannot be achieved conventionally. A cutout is formed between one end and an opposite end of a rectangular metal thin plate to form a plurality of grid plates each having an elongated grid part between the one end and the opposite end. The grid plates are stacked in such a manner that the grid parts of the grid plates are spaced at a given interval and face each other, thereby forming a grid plate stack. In this case, spacers are inserted between one ends and between opposite ends of adjacent ones of the grid plates to form parallel flat plates configured by the grid parts. The grid plate stack forming the parallel flat plates operates as a polarizer for a terahertz wave band.
Nippon Piston Ring Co. and Ibaraki University | Date: 2014-06-04
The generation and propagation of cracks in a connection to a connected member is prevented. A semiconductor device is provided with a connection structure 15 between a bonding wire 17 consisting of an aluminum alloy which contains at least magnesium and silicon and in which a total of contents of the magnesium and the silicon is not less than 0.03 wt% but not more than 0.3 wt% and a silicon chip 16 to which this bonding wire 17 is connected. An aluminum-silicon film 16a is formed on the surface of the silicon chip 16. This connection structure 15 has a compound 18 containing magnesium and silicon in a matrix layer 17a constituting the bonding wire 17, in a fine grain layer 17b of the aluminum alloy formed between the matrix layer 17a and the aluminum-silicon film 16a, and at an interface between the matrix layer 17a and the fine grain layer 17b.
Ibaraki University and Showa KDE Co. | Date: 2013-01-23
Provided are an apparatus and a method for producing an inexpensive Mg_(2)Si_(1-x)Sn_(x) polycrystal that can be effectively used as thermoelectric conversion materials that can be expected to have a high performance index by doping if necessary. A problem can be solved by a production apparatus 1 for producing an Mg_(2)Si_(1-x)Sn_(x) polycrystal including at least a reaction vessel for synthesis of Mg_(2)Si_(1-x)Sn_(x) represented by the following formula (1) by filling a mixture of Mg particles and Si particles or Mg particles and Sn particles, or Mg-Si alloy particles or Mg-Sn alloy particles as a main starting material 2 to cause a reaction; an inorganic fiber layer 6 which is fixedly provided above the starting material 2 filled into the reaction vessel 3 and has air permeability, which can be caused to disappear by a product 7 generated by chemical reaction of vaporized Mg with oxygen during the synthesis of the polycrystal 12; heating means 8 for heating the reaction vessel 3; and control means 9 for controlling the heating temperature and heating time of the reaction vessel 3, whereinMg_(2)Si_(1-x)Sn_(x)(1)(in the formula (1), x is 0 to 1).
Ibaraki University, Japan Science and Technology Agency | Date: 2016-07-06
An objective of the present invention is to easily achieve an extinction ratio in the approximate 10^(-6) class for intensity transmittance in the terahertz band with one element. Provided is a wire grid device, configured from layering a plurality of film substrates (10) each formed from a rectangular polymer film (11) wherein a narrow rectangular metal thin plate (12) is formed in the approximate center of one face thereof. By having the width (a) of the metal thin plate (12) be approximately 1.0mm, the length (1) of the metal thin plate (12) be approximately 12.0-30mm, and the thickness (d) of the film substrate (10) be approximately 0.5-50 m, it is possible to easily achieve an extinction ratio in the approximate 10^(-6) class for intensity transmittance in the terahertz band with one element.
Ibaraki University, Japan Science and Technology Agency | Date: 2014-08-21
Achieve an extinction ratio in the approximate 10^(6 )class for intensity transmittance in the terahertz band with one element. A wire grid device configured from layering a plurality of film substrates each formed from a rectangular polymer film wherein a narrow rectangular metal thin plate is formed in the approximate center of one face thereof. By having the width of the metal thin plate be approximately 1.0 mm, the length of the metal thin plate be approximately 12.0-30 mm, and the thickness of the film substrate be approximately 0.5-50 m, it is possible to easily achieve an extinction ratio in the approximate 10^(6 )class for intensity transmittance in the terahertz band with one element.
Ibaraki University | Date: 2014-04-18
A semiconductor integrated-circuit device using the copper wiring having increased electromigration resistance, low resistivity, and a line width of 70 nm or less, is provided. The present invention is characterized by the annealing treatment wherein a copper wiring having a line width of 70 nm or less is heated with a heating rate of 1K to 10K per second, and then the temperature is constantly maintained for a prescribed time duration.
Ibaraki University | Date: 2014-03-14
Optical axis as central axis is defined as z-axis, and axes perpendicular to z-axis are defined as x- and y-axis. Metallic flat plates are formed parallel to x-z plane to overlap each other and be separated by a given distance. Multiple flat plates except the top flat plate and bottom flat plate are each provided with multiple through holes. Central flat plates are each provided with through holes of a first radius. Intermediate flat plates arranged between central flat plate and top flat plate and between central flat plate and bottom flat plate are each provided with through holes of a second radius smaller than first radius. Second radius of through holes formed in an intermediate flat plate arranged in a position farther from central flat plate is smaller than second size of through holes formed in an intermediate flat plate arranged in a position closer to central flat plate.
Ibaraki University | Date: 2014-12-24
To realize arrangement in place easily and to obtain a desired refractive index. A z-axis is defined as an optical axis and axes perpendicular to the z-axis are defined as an x-axis and a y-axis. Multiple metal plate pieces 10 each have multiple groove portions formed in the direction of the x-axis. An outer shape of the metal plate pieces 10 are such that the respective cross sections of the metal plate pieces 10 are parallel to x-z planes at given intervals of a lens along the y-axis from a lower edge to a center and from the center to an upper edge. A metal dielectric lens 1 is formed by laminating the metal plate pieces 10 such that the metal plate pieces 10 are arranged parallel to the x-z planes at the given intervals. As a result, a refractive index responsive to the number of the groove portions, and the width and the depth of the groove portion can be obtained. And, a resultant structure causes visible light to pass therethrough.