A thermal target including a substrate and a positive temperature coefficient heater. The positive temperature coefficient heater includes at least one pattern of conductive ink printed on the substrate. The positive temperature coefficient heater is configured to provide at least one thermal signature. The positive temperature coefficient heater includes at least one Thermal Coefficient of Resistance (TCR) profile which increases at a set temperature to maintain the at least one thermal signature.

A method for producing a heat exchanger is disclosed. The method includes a) providing two heat exchanger plates of the heat exchanger that are to be joined to one another; b) wetting at least one common local joining zone of the two heat exchanger plates with solder; c) forming the heat exchanger by brazing the two heat exchanger plates via local heating of the at least one common joining zone.

An IR radiator element suitable for use as a miniature infrared emitter (micro-hotplate) in a gas sensor, IR-spectrometer or electron microscope. The micro-hotplate comprises a plate supported by multiple support arms. The plate and arms are fabricated as a MEMS device comprising a single contiguous piece of electrically-conducting refractory ceramic such as hafnium carbide (HfC) or tantalum hafnium carbide (TaHfC). Each of the arms, in addition to providing structural cantilever support for the plate (2), acts as a heating element for the plate. The plate is heated by applying a voltage across the arms. The arms may also be shaped to absorb thermomechanical stress which arises during the heating and cooling of the arms and plate. The plate, which may have an area of less than 0.05 mm2 and a thickness of between 1% and 10% of the largest dimension of the plate, for example, can be heated to 4,000 K or more and cooled again with a duty cycle of as little 0.5 ms, thereby permitting pulsed operation at frequencies of up to 2 kHz. Its small size (10-200 μm) and low power consumption (e.g. 10-100 mW) make the micro-hotplate suitable for use in cryogenic applications, in miniaturized devices or in battery-powered devices such as mobile phones.

In an aspect, an emitting device can comprise a radiation source that emits a source radiation coupled to an edge of an emitting layer; wherein the emitting layer comprises an emitting region comprising a host material and an emitting agent and a non-emitting region comprising the host material and that is free of the emitting agent; wherein the emitting agent comprises at least one of a luminescent agent or an absorber; wherein the emitting layer has a first surface and a second surface; wherein, during use, the source radiation is transmitted from the radiation source through the edge and excites the emitting agent such that, if the luminescent agent is present, the luminescent agent emits an emitted radiation, wherein at least a portion of the emitted radiation exits through the first surface through an escape cone; and, if the absorber is present, the absorber emits heat.

In some examples, preheat three-dimensional (3D) printer build material can include a heating plate of a 3D printer to preheat build material from below the build material, where the heating plate is located adjacent to a build platform of the 3D printer, and a heater-spreader carriage of the 3D printer to preheat the build material from above the build material and spread the preheated build material from the heating plate to the build platform.

Systems and methods for radiative heat transfer are disclosed. In an exemplary embodiment, an infrared heater comprises infrared heating elements and a controller. The infrared heating elements correspond to respective heating zones. The controller causes the infrared heating elements to turn on at different time in succession such that respective heating zones are radiatively heated at different times. In some instances, the respective heating zones correspond to different heating zones of a user, and the user feels a heating wave effect as the infrared heating elements are turned on and off at different times.

Apparatus, systems, articles of manufacture, and methods to provide an adaptive connection of a resistive element and a temperature-dependent resistive element are disclosed. An example apparatus includes a temperature-dependent resistive element. The example apparatus further includes a resistive element. The example apparatus further includes a switch coupled to the temperature-dependent resistive element and the resistive element. The example apparatus further includes a current sensor to measure a current through the temperature-dependent resistive element. The example apparatus further includes a processor to control the switch to, based on the measured current, (A) couple the temperature-dependent resistive element in parallel to the resistive element or (B) couple the temperature-dependent resistive element in series with the resistive element.

Provided is a welding joining method for joining end portions of first and second pipes made of polyamide resin by bonding the end portions to each other by pressure in a molten state. The welding joining method includes: a placing step of placing an infrared radiation lamp between the first and second pipes placed to face each other at an interval; a heating and melting step of heating and melting the end portions of the first and second pipes by emitting infrared; and a pressure bonding step of cooling down the molten end portions in a state where the molten end portions are bonded to each other by pressure.

Systems and methods are provided for controlling infrared radiation (IR) sources of a sauna including tuning IR wavelength-ranges and radiated power-levels of IR sources, and directing IR to locations on a user's body. In one illustrative embodiment, a sauna may be provided having adjustable IR emitters to emit IR at any wavelength resulting in a desirable radiation treatment for the sauna user. In another illustrative embodiment, a method is provided for tuning IR emitters in a sauna.

Provided is a far-infrared ray radiation sheet capable of realizing a heating device exhibiting reduced heat unevenness and a high heat diffusion property, that is highly effective as a heater and good for a human body. There is provided a far-infrared ray radiation sheet 1 formed in a planar shape, that radiates far-infrared rays, the far-infrared ray radiation sheet comprising heat generation type mixed paper 20 formed by mixing a basic material and carbon fiber; electrodes 21 provided to the heat generation type mixed paper 20; heat diffusion type mixed paper 10 formed by mixing the basic material, and the carbon fiber or graphite exhibiting high heat conductivity, that is laminated on the heat generation type mixed paper 20; and prepregs and PET films 23 are laminated on the heat generation type mixed paper 20 and the heat diffusion type mixed paper 10, wherein the far-infrared rays are radiated by applying current to the electrodes 21.