Abstract: The drone according to the embodiment has a propeller, a first direct current motor, a power source, a second direct current motor, and a control unit. The first direct current motor drives the propellers. The power source supplies power to the first direct current motor. The second direct current motor has a rotating shaft that rotates in conjunction with the rotation of a rotating shaft of the first direct current motor. The control unit controls the first direct current motor. The second direct current motor charges the power source using the current output from the second direct current motor along with the rotation of a rotating shaft of the second direct current motor.

Abstract: A lubricated steel material has a lubricating film on the steel surface. The film has good press formability, film removability, and blocking resistance, and possesses a high level of rust preventing properties in that it can prevent the steel material from rusting when kept in stacked or coiled conditions with no oil application. The lubricated steel material is produced by coating a steel material with a coating composition comprising from 74% to 97.7% by weight of an acrylic resin having an acid number of from 30 to 150 and a glass transition temperature of from 5 to 90° C., from 2% to 20% by weight of a water repellant, preferably one or more classes selected from the group consisting of carboxylic acid esters, metal soaps, polyethylene fine powder, and fluoroplastic fine powder, and from 0.

Abstract: A lubricated steel material has a lubricating film on the steel surface. The film has good press formability, film removability, and blocking resistance, and possesses a high level of rust preventing properties in that it can prevent the steel material from rusting when kept in stacked or coiled conditions with no oil application. The lubricated steel material is produced by coating a steel material with a coating composition comprising from 74% to 97.7% by weight of an acrylic resin having an acid number of from 30 to 150 and a glass transition temperature of from 5 to 90° C., from 2% to 20% by weight of a water repellant, preferably one or more classes selected from the group consisting of carboxylic acid esters, metal soaps, polyethylene fine powder, and fluoroplastic fine powder, and from 0.