Abstract:
A vacuum heat insulator according to the present invention includes a core molded to be plate-shaped with the use of a binding agent. The vacuum heat insulator assumes any one of the following configurations. A) The core is formed by curing a fiber aggregate by means of a binding agent. The fibers have an average fiber diameter of at least 0.1 µm but at most 10 µm, and voids defined by fibers have a void diameter of at most 40 µm. The core has a percentage of the voids of at least 80 %. B) The binding agent is varied in concentration in a through-thickness direction of the core. C) A cured layer solidified by the binding agent is formed on at least one side surface of the core. D) The core contains fibers having a length of at most 100 µm. The fibers are oriented perpendicular to a direction of heat transmission. Such vacuum heat insulator is excellent in adiabatic property. Refrigerators, to which such a vacuum heat insulator is applied, are made small in size, or have a large inner volume, or contribute to energy saving.
Abstract:
The judgment about the freshness of food and drink has been made subjectively, and hence often not clear-cut; therefore, investigation has been actively made of the technology to use a semiconductor gas sensor to sense the freshness of food and drink. However, the gas sensors of the prior art have not been capable of sensing gases of, for example, ethylene, ethanol, aldehydes, mercaptans and amines, which are important in sensing the freshness of vegetables and fruits, with satisfactory responsiveness and excellent durability. The gas sensor of the present invention includes: an insulating substrate 1; a pair of thin film electrodes 2 provided on the insulating substrate 1 in such a manner as to leave a fixed space between them; a gas sensitive film 3 including a metallic oxide which is provided in such a manner as to substantially fill at least the fixed space left between the electrodes; and a catalytically active protective layer 5 formed in such a manner as to cover the surface of the metallic oxide exposed to the outside.