Abstract: Disclosed herein is a free drop tester wherein an angle of a test piece can be freely adjusted, a weight can fall on the exact spot, and an impulse of the weight can be controlled, and provides a free drop tester comprising a vertical guide disposed perpendicularly to the ground, a support body for supporting the vertical guide against the floor, a weight of which falling path is guided by the vertical guide, a test piece holder disposed under the bottom surface of the vertical guide, a horizontal rotation shaft of which one end is connected to a test piece holder, a power transmission unit connected to the other end of the horizontal rotation shaft, a test piece angle adjuster including a driving unit for supplying power to the power transmission unit, and a means for adjusting the height of the weight.

Abstract: A rack bar supporting device is a device for supporting a rack bar of a steering apparatus of a vehicle toward a pinion shaft and includes a rack bearing and a biasing assembly. The biasing assembly includes an adjustment plug, an adjustment assembly and a support plate assembly. The adjustment assembly includes an adjustment member and a first biasing member. The support plate assembly includes a first support plate, a second support plate, a second biasing member which provides a force for pushing the first support plate along the biasing axis against the second support plate, and a connection structure which connects the first and the second support plates together so as to restrict movement of the second plate in a direction away from the rack bearing.

Abstract: An apparatus for producing metal nanoparticles using granule type electrodes, in which the metal nanoparticles having a uniform shape and nano-size are continuously mass-produced at low cost by filling metal granules in a pair of electrode housings spaced by a certain interval and electrolyzing the granules with alternating-current voltage. The apparatus includes a reaction vessel containing an electrolytic solution, first and second electrodes that are formed by filling a number of granules or flakes, in first and second electrode housings that are spaced by a gap in the reaction vessel, and a power supply that applies an alternating-current power between the first and second electrodes for electrolysis reaction, in which the first and second electrode housings comprise a number of holes or slits on at least two surfaces facing each other so that metal ions dissolved from the first and second electrodes can be discharged depending on the electrolysis reaction.

Abstract: Provided is a method and apparatus for producing silver nanoparticles in uniform shape and size using an electrolysis eco-friendly and in a simple way.

Abstract: Disclosed herein are a method and apparatus for preparing metal nanoparticles using alternating current (AC) electrolysis, in which the yield of metal nanoparticles obtained can be greatly improved by maintaining the concentrations of a reducing agent and a dispersing agent at constant levels in proportion to the intensity of an electric current during the production of the metal nanoparticles.

Abstract: Disclosed is a motion simulation pad. More particularly disclosed is a motion simulation pad, which is compact, lightweight, inexpensive and suitable for virtual reality games. The motion simulation pad according to the present invention includes: a lower plate (200); an upper plate (300) disposed above the lower plate (200) in such a manner as to be spaced apart from the top surface of the lower plate (200) via a supporting universal joint (310); a rotating plate (400) rotatively installed on the upper portion of the upper plate (300); and a pair of driving means for transmitting a driving force to two points of the upper plate (300) to allow the upper plate to perform a seesaw/movement by using the supporting universal joint (310) as a seesaw shaft.