Abstract: An optical soil survey device to survey the optical characteristics of a given underground soil, a soil survey device to survey the soil, a soil survey system and a mobile soil survey vehicle to survey the soil are disclosed. The disclosed devices and systems may be used to survey the characteristics of a given soil for agricultural purposes. This survey can be carried out without experiencing significant resistance from the soil. A plow-shaped optical soil survey device may be provided with a plow-shaped main unit, whose forward extremity turns up soil; a frame, which supports the sensor and connects a tractor and a main unit; a spectrometer, which is mounted on the frame; a wheel, which surveys the depth of the furrow and is connected to the main unit via an arm; and a survey control unit, which is mounted on the tractor.

Abstract: A steam valve provided for a turbine system of a power plant comprises a by-pass valve provided with a plurality of holes through which steam from a boiler enters into the by-pass valve, a main valve connected thereto, and a valve rod. The by-pass valve is provided with an inner chamber the bottom portion of which is enlarged.