Provided is a display device. The display device includes a lower display element where a substrate, a first lower electrode, a liquid crystal part, and a second lower electrode are sequentially stacked, an upper display element stacked vertical to the lower display element, where a first upper electrode, a light emitting part, a second upper electrode, and a protective part are sequentially stacked, and a middle part configured to deliver a driving signal to the lower and upper display elements, between the lower and upper display elements.

Display device and method of fabricating the same

A TV audience survey system for determining the TV viewing activities of a plurality of individuals in a household includes a master device and multiple tags, each tag assigned to an individual. After an individual logs into the system and starts watching the TV, the master device communicates with the corresponding tag repeatedly to accumulate data representing the individual's TV viewing activities. Such data can be used to determine when the individual stops watching the TV for an extended period of time without logging out of the system and when the household member remains watching the TV after logging or being logged out of the system. The master device then reports the accumulated data to a remote server, which uses the data to determine whether the individual complies with the logging protocol defined by the TV audience survey system and update the TV viewership data associated with this household.

Logging individuals for tv measurement compliance

This paper evaluates the electromagnetic characteristics as to two types of superconducting motors: one is the superconducting motors adopting high-temperature superconducting field coils and copper armature windings; and the other is fully-superconducting motors, which have high-temperature superconducting field coils and MgB
 2
 superconducting armature windings. Analytical formulas and FEM are employed for the designs of 1.5-, 3.0-, and 5.0-MW motors. We consider how to reduce ac loss in MgB
 2
 winding structure as well. The analysis of our results, which was conducted mainly over output density and efficiency, suggests that the adoption of superconducting motors is more realistic in realizing electrical aircraft propulsion system in terms of higher output; the analysis results show that the fully-superconducting motors have a potential to reach over 16 kw/kg.

Electromagnetic Design of Superconducting Synchronous Motors for Electric Aircraft Propulsion

https://iopscience.iop.org/article/10.1088/0953-2048/29/11/113004/pdf

The development of MgB2 superconducting wires fabricated with an internal Mg diffusion (IMD) process

The effects of the grain size, lattice strain, and microstructure on the trapped field properties of ball-milled MgB2 bulks were studied. A decrease in the in-plane lattice parameters and transition temperature and an increase in the in-plane x-ray diffraction peak widths occurred with milling as a result of grain refinement and carbon substitution. Microstructural analysis revealed that sub-micron-size fine MgB2 grains were well connected, resulting in increased grain boundary density. The trapped field of the magnetized bulk samples exhibited a large improvement with milling and reached 3.72 T at 5 K, which is the highest among MgB2 bulks prepared using pressureless synthesis. Excess milling resulted in degradation of the trapped field because of Tc reduction. The increased grain boundary density and electron scattering are considered to contribute to the high trapped field through quantitatively and qualitatively enhancing the grain boundary flux pinning.

https://iopscience.iop.org/article/10.1088/0953-2048/28/5/055016/pdf

Enhanced trapped field in MgB2 bulk magnets by tuning grain boundary pinning through milling

Aiming to understand the bending characteristics of a MgB2 thin-film wire and utilize the wire in the design of superconducting magnets, we examined the degradation of critical current density J c due to bending. Six short MgB2 thin-film wires with a thickness of 1 μm were prepared under the same deposition conditions. They were bent in different radii, and their J c were compared. The allowable bending radius at which J c does not degrade was 25.0 mm. As for MgB2 thin-film wires, thickening the film effectively increases the engineering critical current density J e. On the basis of material mechanics, the allowable bending radius was estimated to be 25.5 mm when the film thickness increased to 10 μm. The allowable bending radius of the MgB2 thin-film wire is sufficiently smaller than the radius of a typical superconducting coil, so it is not considered to be a barrier to fabricating a coil with the wire.

Flexural properties of a MgB2 thin-film wire

We are now developing a new in-situ deposition process for MgB2 film as a candidate method to mass-produce MgB2 thin film superconducting tape. In the new method, a MgB2 film is deposited on a heated metal substrate by a hybrid deposition method, which consists of thermal evaporation of magnesium and sputtering of boron. By using the hybrid deposition method, the substrate temperature can raise from 250 to 350°C, while its fluctuation is kept less than 1°C, which will improve the quality and reproducibility of MgB2 film in mass production. The Jc of MgB2 film deposited by the hybrid deposition method at 20 K and self-field was more than 30,000 A/mm2, which was better than the results reported by the two-step in-situ process using DC sputtering and 830°C high-temperature post annealing [17] or by the as-grown depostion using sputttering targets of Mg and B [18]. Although we obtained better Jc than other deposition methods that use sputtering process, the Jc is still lower than the value we obtained by using a co-evaporation method with electron beam (EB). We investigated the film structure and Jc-B-T properties of the film made by the hybrid deposition method and compared them with those of the film made by co-evaporation. From the analysis results, we think the reasons for the lower Jc are the larger amount of heterogeneous phases such as magnesium oxides in the film and the amorphous B phase under the MgB2. We expect to improve the the crystal qualities and superconductivities of the MgB2 film deposited by the new method by removing impurities in Ar gas during sputtering and thinning the B amorphous phase by increasing the Mg deposition rate in the initial stage of deposition.

https://robots.iopscience.iop.org/article/10.1088/2053-1591/ab945a/pdf

Motomune Kodama

Papers

Flexural properties of a MgB2 thin-film wire

New deposition method of MgB2 thin film with thermal evaporation of Mg and sputtering of B

Vorläufer eines MgB2-Supraleiters und Herstellungsverfahren dafür