An airfoil (300) comprises a skin (310), comprising an external surface (312) and an internal surface (314). The skin (310) has a controlled region (316). The airfoil (300) also comprises an interior space (308), formed by the skin (310). The airfoil (300) additionally comprises a hybrid acoustic induction-heating system (302), configured to impede formation of ice on the external surface (312). The hybrid acoustic induction-heating system (302) comprises induction coils (328) and a control system (350). Each one of the induction coils (328) has a portion (336), arranged sufficiently close to the internal surface (314) to produce an eddy current (380) within the controlled region (316). The control system (350) is configured to generate inductive heat and traveling-wave acoustic pressure in the controlled region (316) by supplying different phases (348) of the alternating electrical current (334) to the induction coils (328) based, at least in part, on an ambient temperature of a layer of fluid (318) flowing over the external surface (312).

A concrete heating system for electrically melting snow and ice. The concrete heating system generally includes a heating device for embedding in conductive concrete, the device having a spacing member and a plurality of electrically isolated conductors extending outward at an angle from the spacing member along its length. The device also includes a first electrode near the first end of the spacing member, and a second electrode extending outward from the spacing member at the second end. The plurality of conductors conduct an electrical current between the first electrode and the second electrode when the concrete heating device is embedded in conductive concrete and the power source applies a voltage between the first electrode and the second electrode.

A heating cable that is usable in train track applications where railroad switches are subject to icing during cold weather, the heating cable including a coiled resistance heating wire contained in an electrical insulator, which is contained in an inner braided metal sleeve, which is contained in a flexible metal hose, which is contained in an outer braided metal sleeve.

A heated composite structure and a method for forming a heated composite structure. The structure includes carbon fibers embedded within a thermoplastic matrix. The carbon fibers are connected with first and second electrodes that are configured to be connected with an electric source such that applying current to the electrodes causes current to flow through the embedded carbon fibers to provide resistive heating sufficient to heat the composite structure to impede formation of ice on the composite structure.

A snow and ice removal device may include one or more, heating elements. A control unit may be configured to control the heating element to produce heat. A power source may be in electrical communication with the control unit and the heating element. Heat may be applied to the roof surface by the heating element to loosen and/or melt accumulated ice or snow from the roof surface of the vehicle.

A roofing heating system that includes: a building; a roof, where the roof covers provides cover for the building; a series of heating elements within an interior surface of the roof; and connection wires, where the connection wires link the heating elements to a thermostat and a power source. The series of heating elements are preferably arranged in a series of rows and columns covering the inner surface of the roof. The heating elements enable heat transfer to an outer surface of the roof in order provide adequate temperatures to avoid accumulation of snow and ice on the outer surface of the roof.

A heater for vehicular sensors is configured to pass sensing energy and thereby permit placement of the heater directly over the sensing area in the path of the sensed energy. In this way, direct heating of the sensing area is provided minimizing the energy necessary to prevent icing and improving deicing speed.

A snow melting apparatus for melting snow on sidewalks, driveways, and other walkways is provided. The snow melting apparatus comprises a plurality of individual heating cables with the heat cables woven together to form a mesh-like covering mat and the covering mat having a top surface and a bottom surface. An outer perimeter border surrounds the covering mat. A snowfall sensor mechanism is mounted to the covering mat with the snowfall sensor mechanism detecting precipitation and automatically activating the heating cables. The top surface of the covering mat is presented for a person to walk and or stand while the bottom surface of the covering mat is capable of being positioned against the sidewalk, driveway, or other walkway. Upon activation of the heating cables, the temperature of the heating cables increases thereby heating the entire covering mat.

A skin effect heating system for long pipelines includes a heater cable disposed in a ferromagnetic or other conductive heat tube, the heater cable and heat tube cooperating to produce heat that is applied to the carrier pipe. The heater cable includes a conductor surrounded by an insulating layer, and then a semiconductive outer layer or “jacket.” The semiconductive jacket contacts the inner surface of the heat tube, where the charge density of the return current carried by the heat tube is at its highest. The semiconductive jacket material has a resistivity that is sufficiently low to reduce or eliminate arcing events such as corona discharge by allowing accumulated charge on the heat tube to dissipate. The resistivity is also high enough to prevent the return current from flowing into or through the semiconductive outer layer, so that heat production capacity of the system is maximized.

A method of tuning an electrical resistance of a laser-induced graphene heater is provided. The method includes forming a base carbon heating element, and determining a target electrical resistance of a laser-induced graphene (LIG) heater to be fabricated from the base carbon heating element. The method further includes determining a targeted LIG pattern that provides the target electrical resistance, and directing laser energy on to the base carbon heating element based on the targeted LIG pattern to form one or more LIG regions. The one or more LIG regions define a LIG pattern to from the LIG heater having the target electrical resistance.