A long wavelength infrared sensor includes a first magnetoresistive unit; a second magnetoresistive unit; and a light absorption layer that absorbs light and emits heat, wherein the first magnetoresistive unit includes a first magnetoresistive element and a second magnetoresistive element electrically connected to each other, the second magnetoresistive unit includes a third magnetoresistive element and a fourth magnetoresistive element electrically connected to each other, the first and third magnetoresistive elements each have an antiparallel state of magnetization direction, the second and fourth magnetoresistive elements each have a parallel state of magnetization direction, and the first magnetoresistive element is electrically connected to the third magnetoresistive element by way of the second magnetoresistive element.

To increase thermoelectromotive voltage of a thermoelectric conversion element with a magnetization direction, a temperature gradient direction, and an electromotive force direction orthogonal to each other. A thermoelectric conversion element 1 is formed by annularly winding a thermoelectric material which is radially magnetized and circumferentially generates an electromotive force in accordance with a temperature gradient in the axial direction thereof. Thus, the thermoelectric material is wound not linearly but annularly, so that a connection line for connecting a plurality of thermoelectric materials is not necessary. In particular, when the thermoelectric material is wound in a plurality of turns, the length per unit area of the thermoelectric material in the direction of the electromotive force can be significantly increased, making it possible to significantly increase thermoelectromotive voltage while suppressing increase in the size of the element.

To obtain a high thermoelectromotive voltage with a simple structure in a thermoelectric conversion element with a magnetization direction, a temperature gradient direction, and an electromotive force direction mutually orthogonal. A thermoelectric conversion element 1 includes a tape-like member 10 including an insulating film and a thermoelectric material layer formed on the surface of the insulating film and having a magnetization direction, a temperature gradient direction, and an electromotive force direction which are mutually orthogonal and a pair of terminal electrodes E1 and E2 connected to the thermoelectric material layer at positions different in the longitudinal direction thereof. The tape-like member 10 is wound with the longitudinal direction thereof directed to the circumferential direction, and the thermoelectric material layer is radially magnetized. Thus, the radially magnetized tape-like thermoelectric material layer is circumferentially wound, so that a thermoelectromotive voltage can be generated in accordance with a temperature gradient in the axial direction. In addition, the electromotive force occurs circumferentially, making the structure of the tape-like member simple.

A process for liquefying a process gas that includes introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises a single stage comprising dual multilayer regenerators located axially opposite to each other.

A process for liquefying a process gas that includes introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises a single stage comprising dual multilayer regenerators located axially opposite to each other.

A thermoelectric conversion device (20) includes a substrate (22) and a plurality of thermoelectric conversion elements (24, 25) on the substrate (22) . Each of the plurality of thermoelectric conversion elements (24, 25) has a rectangular parallelepiped shape and is made of an alloy including Fe.sub.3Sn.sub.2, an iron nitride (such as Fe.sub.16N.sub.2), or a rare-earth element and Co, the alloy exhibiting an anomalous Nernst effect. The thermoelectric conversion elements (24, 25) are arranged parallel to a direction (y direction) perpendicular to a longitudinal direction (x direction) to form a serpentine shape, and electrically connected in series.

A thermoelectric conversion device (20) includes a substrate (22) and a plurality of thermoelectric conversion elements (24, 25) on the substrate (22) . Each of the plurality of thermoelectric conversion elements (24, 25) has a rectangular parallelepiped shape and is made of an alloy including Fe.sub.3Sn.sub.2, an iron nitride (such as Fe.sub.16N.sub.2), or a rare-earth element and Co, the alloy exhibiting an anomalous Nernst effect. The thermoelectric conversion elements (24, 25) are arranged parallel to a direction (y direction) perpendicular to a longitudinal direction (x direction) to form a serpentine shape, and electrically connected in series.

A process for liquefying a process gas that includes introducing a heat transfer fluid into an active magnetic regenerative refrigerator apparatus that comprises a single stage comprising dual multilayer regenerators located axially opposite to each other.

A thermoelectric conversion element that has a power generation layer containing an iron-aluminum based magnetic alloy material containing equal to or more than 70 weight percent of iron and aluminum in total. The power generation layer generates an electromotive force, due to an anomalous Nernst effect that develops in the magnetic alloy material in response to a temperature gradient applied thereto, in a direction intersecting both the magnetization direction of the magnetic alloy material and the direction of the applied temperature gradient.

Integrated arrangements of electrical machines and power electronics converters are described. One such arrangement comprises: an electrical machine comprising one or more windings; a power electronics converter arranged to supply current to or receive current from the one or more windings of the electrical machine; a magnetocaloric effect (MCE) material in thermal contact with the power electronics converter; and a heat sink for removing heat from the MCE material. The MCE material is arranged in proximity to the one or more windings of the electrical machine whereby, in use, stray magnetic flux from the windings of the electrical machine passes through the MCE material and activates the MCE material. The repeated application and removal of the stray flux during normal operation of the electrical machine creates cycles of magnetic refrigeration, which removes heat from the power electronics converter.