Abstract: A gas detecting element that can effectively prevent fluctuations in measurement sensitivity caused by diffusion of a reagent as well as the occurrence of corrosion. The gas detecting element comprises a frame 1 with an optical density detection window 4 that is not gas-permeable formed on one side to allow optical density detection, and a gas-permeable window 6 formed on the opposing side, with a reagent absorbent material 7 being housed between the two windows and impregnated with a reagent that undergoes coloration change by reaction with a gas to be measured.

Abstract: A detecting material to detect formaldehyde at low concentration in the atmosphere in a short time is prepared by impregnating a base material containing at least silica gel with a coloring liquid containing 4-amino-4-phenyl-3-ene-2-one and a buffer solution and volatilizing the solvent.

Abstract: This invention provides a gas detecting sheet, which can detect a plurality of gases at the approximately same time, so as to be able to easily detect which of the gases is leaked, in an environment where the leaks of a plurality of kinds of gases are estimated, and discloses a gas detecting sheet which can measure the concentration of a detection target gas in a environment where an interference gas exists. A base plate and a plurality of gas detectors are formed. The kinds of the target gases to be detected by the various gas detectors are different. The base plate is designed so as to be attachable to and detachable from a gas detecting unit for measuring the gas concentration. Also, when one gas detector is used to detect the detection target gas and the other gas detector is used to detect the interference gas, the detector for the detection target gas determines the total concentration of the detection target gas and the interference gas.

Abstract: A detecting material to detect formaldehyde at low concentration in the atmosphere in a short time is prepared by impregnating a base material containing at least silica gel with a coloring liquid containing 4-amino-4-phenyl-3-ene-2-one and a buffer solution and volatilizing the solvent.

Abstract: A porous cellulose tape impregnated with powdered silica or other gas adsorbent carries a coloring reagent of silver perchlorate or silver para-toluenesulfonate and a light-resistance enhancer of para-toluenesulfonic acid which are dissolved in glycol. When the tape is exposed to a sample gas, the silane contained in it dissolves in the glycol. The resulting reduction of the silver perchlorate or silver para-toluenesulfonate forms a colloid of silver as a trace of their reaction. The concentration of silane, which is proportional to the colloid of silver formed, can be determined by measuring the optical concentration of the reaction trace. The absence of strong acid detrimental to cellulose assures the determination of silane concentration with a high degree of sensitivity, without impairing the mechanical strength in the cellulose tape.

Abstract: Apparatus and a method are provided for working and finish-treating the surfaces of stones by jetting a flow consisting solely of water, at a pressure of 200 kg/cm.sup.2 or more, toward the stone surface which previously may have been cut by a gang saw or a circular saw cutting machine, bush hammered or dabbed finished, bush hammered and then dabbed finished, bush hammered and then flamed or directly flamed without being bush hammered so that the surface of the stones is roughed and crystal particles in the stones are exposed.

Abstract: A tape for detecting the presence of hydride gases by taking advantage of coloring reactions whose light sensitivity is lowered to a minimum without impairing the inherent mechanical strength of the reagent holder. The detection tape is prepared by impregnating a tape of porous cellulose fibers containing a gas adsorbent such as a powder of silica and a moisture keeper of glycerin with a coloring reagent of silver perchlorate or silver para-toluenesulfonate and a light resistance enhancer of para-toluenesulfonic acid. When the detection tape is exposed to a hydride gas contained in the sampled gas, silver perchlorate or silver para-toluenesulfonate is reduced by the hydride gas to form a colloid of silver that remains as a trace of reaction. As the amount of the colloid of silver is proportional to the concentration of the gas, the concentration of hydride gas can be determined by measuring the optical density of the trace of reaction.

Abstract: A process is provided for separation of an asbestos-containing material from a surface to which the asbestos-containing material is adhered, while preventing floating of dust of the removed asbestos-containing material, the process requiring jetting of pressurized water from a plurality of nozzles to the surface at a pressure of at least 80 kg/cm.sup.2 so as to wet and remove the asbestos-containing material therefrom by the energy possessed by the pressurized water.

Abstract: A method for removing substances adhering to a surface such as a wall of buildings in which a nozzle head having a plurality of nozzles is rotated eccentrically and moved sidewardly when used. The diameter of each of the nozzles is selected so as to be within a range of 0.05 to 0.5 mm, the pressure to be supplied to the nozzles is 800 kg/cm.sup.2 or more, the total amount of water jetted from each of the nozzles is 12 l/min or less and the number of revolutions of the nozzle head is 800 to 4000 rpm.

Abstract: An antenna including a first elongated magnetic member having at least one diamagnetic portion and a first magnetic pole orientation, a second elongated magnetic member having at least one diamagnetic portion and a second magnetic pole orientation opposite to the first magnetic pole orientation and provided adjacent and parallel to first elongated magnetic member, a pair of third elongated magnetic members connecting the ends of the first and second elongated members to form a magnetic loop and a coil wound on each of the first and second elongated magnetic members.