Disclosed is a development apparatus that includes a first roller to be supplied with developer accommodated in a first chamber, a first magnet, a second roller to which the developer is delivered from the first roller through a magnetic field generated by the first magnet, which is arranged to face the first roller, the second roller bearing and conveying the developer to collect the developer in a second chamber after the electrostatic latent image is developed, and a second magnet, in a case where ten-point average roughness of an outer circumferential surface of the first roller is Rz1 and ten-point average roughness of an outer circumferential surface of the second roller is Rz2, 0.35Rz1Rz2 and 7 mRz115 m.

Disclosed is a development apparatus that includes a first roller to be supplied with developer accommodated in a first chamber, a first magnet, a second roller to which the developer is delivered from the first roller through a magnetic field generated by the first magnet, which is arranged to face the first roller, the second roller bearing and conveying the developer to collect the developer in a second chamber after the electrostatic latent image is developed, and a second magnet, in a case where ten-point average roughness of an outer circumferential surface of the first roller is Rz1 and ten-point average roughness of an outer circumferential surface of the second roller is Rz2, 0.35Rz1Rz2 and 7 mRz115 m.

A system for blast-cleaning a barge deck, sides, and fittings providing for safety and avoidance of damage to the barge and to persons, where a barge is blast-cleaned with moving blaster units suspended from and traveling along an overhead track beam. In one embodiment, the moving blaster units are each controlled by a person in a moving operator capsule moving in tandem with a moving blaster unit. In another embodiment, the moving blaster units are robotically controlled from a robotic controller which has access to a three-dimensional plan of the barge, communicating with the robotic blaster units via RF antennae, and receiving real-time data from sensors located on each blaster head. Optionally, the system for blast-cleaning a barge can provide blaster-head cameras for real-time remote monitoring of operations and for recording of the operations allowing review of any issue, such as damage, that might arise.

A system for blast-cleaning a barge deck, sides, and fittings providing for safety and avoidance of damage to the barge and to persons, where a barge is blast-cleaned with moving blaster units suspended from and traveling along an overhead track beam. In one embodiment, the moving blaster units are each controlled by a person in a moving operator capsule moving in tandem with a moving blaster unit. In another embodiment, the moving blaster units are robotically controlled from a robotic controller which has access to a three-dimensional plan of the barge, communicating with the robotic blaster units via RF antennae, and receiving real-time data from sensors located on each blaster head. Optionally, the system for blast-cleaning a barge can provide blaster-head cameras for real-time remote monitoring of operations and for recording of the operations allowing review of any issue, such as damage, that might arise.