Nec Corporation

Asahi Kasei Kabushiki Kaisha

Takahide Yoshida

Yutaka Gojo

Hiroshi Toyao

Eiji Hankui

A method for washing a filter is used in a seawater desalination process including a first filtration step for subjecting seawater to microfiltration or ultrafiltration, and a second filtration step for subjecting seawater after the first filtration step to a reverse osmosis treatment. The filter is a microfiltration membrane or ultrafiltration membrane used in the first filtration step. An iron compound is added to seawater in any stage in the washing method. The washing method includes a washing chemical liquid preparation step for preparing washing chemical liquid, and a sticking matter removal step for removing matter sticking to the filter by bringing the filter into contact with washing chemical liquid. In the washing chemical liquid preparation step, seawater after the first filtration step is mixed with at least hydrogen peroxide to prepare washing chemical liquid having an iron compound concentration of 1.50 mmol/L or more in terms of iron atoms.

Method for washing filter and method for desalinating seawater

This method, for regenerating a member used in a device that treats seawater, involves a cleaning step for removing deposits from the member. In the cleaning step, a first chemical solution containing an acid other than hydroxydicarboxylic acid and a second chemical solution containing hydrogen peroxide, a heavy metal compound and hydroxydicarboxylic acid are used.

Method of regenerating member and method of seawater desalination

An object of the present invention is to provide a method for designing a gradient index lens enabling to easily and accurately drive an antenna. According to the present invention, a virtual domain a boundary of which includes a curved focal plane in a uniform-refractive-index type lens with a uniform refractive index, and a physical domain a boundary of which includes a planar focal plane in a gradient index lens with a non-uniform refractive index and that is a quasiconformal map of the virtual domain are set, the quasiconformal map of a virtual medium parameter that is a medium parameter including at least one of a dielectric constant and magnetic permeability characterizing the virtual domain is calculated as a physical medium parameter in the physical domain, and the gradient index lens based on the physical medium parameter is designed by spatially arranging a medium parameter adjustment element set in advance.

Method for designing gradient index lens and antenna device using same

It has been difficult to suppress electromagnetic wave that propagates within a suspended substrate. The structure according to the present invention is provided with: a first conductor plane and a second conductor plane that are disposed parallel to each other; a dielectric plane that is disposed between the first and second conductor planes via a hollow region so as to be parallel to the first and second conductor planes; a first transmission line disposed on a surface that is of the dielectric plane and that opposes the first conductor plane; and a second transmission line disposed on a surface that is of the dielectric plane and that opposes the second conductor plane, wherein the first transmission line and the second transmission line are electrically connected to each other.

Structural body, laminated structure of structural body, and antenna structure

An object of the present invention is to provide an antenna device having a wide beam scan range with reduced loss. The antenna device according to one aspect of the present invention includes: a first phase shifter, a second phase shifter, and a third phase shifter; a first connection part that electrically connects between the first phase shifter and the second phase shifter directly in series; a second connection part that electrically connects between the second phase shifter and the third phase shifter directly in series; and a power feed part that feeds electric power to the first phase shifter to the third phase shifter, wherein the first phase shifter and the second phase shifter, and the second phase shifter and the third phase shifter respectively have characteristic impedance being discontinuous with respect to each other at the first connection part and the second connection part.

Growing community of inventors

Tokyo, Japan

Takahide Yoshida