Abstract: A density-moisture measuring apparatus includes an NaI scintillator 4 which detects only a gamma ray from a californium 1 which has passed through an object 20, a plastic scintillator 15 for detecting the gamma ray and a fast neutron ray, and a photomultiplier 6 coupled to these scintillators. It can be said that there is a proportional relation between gamma ray data Nc and N.gamma. which have passed through the object 20 detected by the NaI scintillator 4 and the plastic scintillator 15. The gamma ray data and the fast neutron ray data N.gamma. and Nn detected by plastic scintillator 15 are not separated from each other even by a pulse-shape discrimination, but they can be separated by using a relation between gamma ray data Nc detected by the NaI scintillator 4 and the gamma ray data detected by the plastic scintillator 15. Further, since a plastic scintillator 15 is used, handling is easy.

Abstract: The invention provides a material useful as a slope face protective material for use in civil engineering work or the like, as a water contact material or a filter material for forming biological films for use in biological water treatment by an aeration or nonaeration process, and a material for underwater nurseries for growing laver or like vegetables, artificial fish-breeding shelters, hydroponic culture beds, etc. The material includes at least one sheet having predetermined flexibility and rigidity and at least one rope attached in a wavelike form to the sheet, the sheet having a plurality of incisions which are openable when the rope is stretched from the wavelike form to deform the sheet and form a multiplicity of flaps raised with respect to the axis of the rope.

Abstract: The invention provides a sheet for forming twisted flaps in a continuous arrangement which comprises a sheet material and a stitching thread attached to the sheet material to form one or a plurality rows of stitches in a wave pattern or stitches in a reticular pattern, the sheet material being formed with incisions each in each of areas surrounded by stitches. When the thread is pulled, the sheet material is opened at the incisions to form a multiplicity of raised, curved flaps inclined with respect to the longitudinal direction of the thread. Methods of producing such sheets are also provided. The sheet provided is advantageously usable as a water contact material for biological water treatment, slope protective material for civil engineering work, etc.

Abstract: Herein disclosed is a copper bit cleaner which comprises a casing formed with a bit aperture for allowing the copper bit of a soldering tool to be inserted therethrough, and a plurality of solder residue scraping members having a flexibility and formed into a line, strip, ribbon or band shape. Solder residue scraping member holding means is cased in the casing for holding said solder residue scraping members in a straight, curved or looped shape. Drive means is used for rotationally driving the solder residue scraping member holding means at a high speed so that the solder residue scraping members may slide on the circumference of the copper bit, which is inserted through the bit aperture, at a high speed to scrape off the solder residue thereby to split the scraped solder residue off from the solder residue scraping members by the centrifugal forces thereof.