A travelling apparatus, including: a rail; at least one vehicle, for travelling in a direction being along the rail; and a holding structure, for holding a user to stand on the at least one vehicle, with one foot in front of another along the travelling direction, thereby forces produced by the travelling, are applied on one side of the user in relation to the other, thus being safe to the user, thereby diminishing width of the rail.

A travelling apparatus, including: a rail; at least one vehicle, for travelling in a direction being along the rail; and a holding structure, for holding a user to stand on the at least one vehicle, with one foot in front of another along the travelling direction, thereby forces produced by the travelling, are applied on one side of the user in relation to the other, thus being safe to the user, thereby diminishing width of the rail.

An aspect of the present disclosure provides a method for measuring a quantity of liquid in a liquid-insulated electrical component. The liquid-insulated electrical component includes a main tank (1) and an expansion tank (2) fluidly connected to the main tank (1). The method includes measuring a first pressure (P.sub.1) of the liquid at a first point in the main tank (1), measuring a second pressure (P.sub.2) of the liquid at a second point in the main tank (1), the second point being at a height (H) above the first point, measuring a third pressure (P.sub.3) of the liquid at a third point in the expansion tank (2), and determining the quantity of liquid in the liquid-insulated electrical component based, on the first pressure (P.sub.1), the second pressure (P.sub.2) and the third pressure (P.sub.3). Further aspects provide a liquid-insulated electrical component, particularly a transformer, more particularly a traction transformer (101) for a railroad vehicle (100), as well as a railroad vehicle (100) including said liquid-insulated electrical component

An aspect of the present disclosure provides a method for measuring a quantity of liquid in a liquid-insulated electrical component. The liquid-insulated electrical component includes a main tank (1) and an expansion tank (2) fluidly connected to the main tank (1). The method includes measuring a first pressure (P.sub.1) of the liquid at a first point in the main tank (1), measuring a second pressure (P.sub.2) of the liquid at a second point in the main tank (1), the second point being at a height (H) above the first point, measuring a third pressure (P.sub.3) of the liquid at a third point in the expansion tank (2), and determining the quantity of liquid in the liquid-insulated electrical component based, on the first pressure (P.sub.1), the second pressure (P.sub.2) and the third pressure (P.sub.3). Further aspects provide a liquid-insulated electrical component, particularly a transformer, more particularly a traction transformer (101) for a railroad vehicle (100), as well as a railroad vehicle (100) including said liquid-insulated electrical component

In a power conversion device, a distance between an output terminal of a first switching module and a cathode terminal of a first diode module in a first direction is arranged to be substantially equal to a distance between an output terminal of a second switching module and an anode terminal of a second diode module in the first direction.

A Rail Drone can include: a payload interface, a drivetrain, and a rail platform 515. The Rail Drone can additionally or alternatively include any other suitable set of components. The Rail Drone can integrate a standardized payload interface and an autonomous electric road vehicle platform into a rolling stock architecture. The Rail Drone can be a stand-alone, payload-agnostic, motive element which can be independently or cooperatively capable of carrying heavy loads across long distances at various cruising speeds.

A Rail Drone can include: a payload interface, a drivetrain, and a rail platform 515. The Rail Drone can additionally or alternatively include any other suitable set of components. The Rail Drone can integrate a standardized payload interface and an autonomous electric road vehicle platform into a rolling stock architecture. The Rail Drone can be a stand-alone, payload-agnostic, motive element which can be independently or cooperatively capable of carrying heavy loads across long distances at various cruising speeds.

A semiconductor device of embodiments includes: a silicon carbide layer having a first face and a second face opposite to the first face, and including a p-type silicon carbide region in contact with the first face, a percentage of a first silicon atom among a plurality of silicon atoms present in a first layer as an uppermost layer being equal to or more than 90% and a site position of the first silicon atom being different from a site position of a silicon atom in a third layer from the first face and the same as a site position of a silicon atom in a fifth layer from the first face; a gate electrode; a silicon oxide layer between the silicon carbide layer and the gate electrode; and a region between the silicon carbide layer and the silicon oxide layer including nitrogen.

A semiconductor device of an embodiment includes: a silicon carbide layer including a first silicon carbide region of n-type containing one metal element selected from a group consisting of nickel (Ni), palladium (Pd), platinum (Pt), and chromium (Cr) and a second silicon carbide region of p-type containing the metal element; and a metal layer electrically connected to the first silicon carbide region and the second silicon carbide region. Among the metal elements contained in the first silicon carbide region, a proportion of the metal element positioned at a carbon site is higher than a proportion of the metal element positioned at an interstitial position. Among the metal elements contained in the second silicon carbide region, a proportion of the metal element positioned at an interstitial position is higher than a proportion of the metal element positioned at a carbon site.

A Rail Drone can include: a payload interface, a drivetrain, and a rail platform(515). The Rail Drone can additionally or alternatively include any other suitable set of components. The Rail Drone can integrate a standardized payload interface and an autonomous electric road vehicle platform into a rolling stock architecture. The Rail Drone can be a stand-alone, payload-agnostic, motive element which can be independently or cooperatively capable of carrying heavy loads across long distances at various cruising speeds.