Abstract: A masonry coring system for drilling vertical holes in a masonry wall comprises a drill bit in the form of a thin-walled cylinder having a cutting end face, a plurality of cutting elements fastened to the cutting end face, and a core breaker located within the interior of the cylinder. The coring system further comprises a driver plate fastened to the drill bit opposite the cutting end face, a driver shaft having a small axial hole therein fastened to the upper surface of the driver plate, a hydraulic motor to rotate the driver shaft, a non-rotating plastic pipe slightly larger than and surrounding the driver shaft, the plastic pipe resting on the driver plate and containing a plurality of holes located at the end near the driver plate. An air compressor forces compressed air through the axial hole in the driver shaft. An evacuation system withdraws the drilling dust through the annulus between the driver shaft and pipe and into a dust collector.

Abstract: A technique of determination of nitrate-nitrite content of a test sample, without also determining additional nitrogen content. The technique is highly selective and sensitive, to the parts per billion level. The nitrate-nitrite content of a sample is reduced to nitric oxide which is determined via its chemiluminescence reaction with ozone. Nitrite is selectively reduced under mild conditions and the total nitrate-nitrite content is determined by stronger reduction conditions. Specific reducing agents to be used in combination with the chemiluminescence reaction are also provided.

Abstract: N-nitrosamines are reacted with a denitrosating agent to cleave the N-NO bond and yield nitric oxide which may be analyzed to determine both qualitatively and quantitatively, the N-nitrosamine content of a test sample. The denitrosating reagent has the advantage of being useful, even in the presence of substantial amounts of water, and comprises a mixture of glacial acetic acid and a concentrated inorganic acid which is either phosphoric acid or sulfuric acid. The volume ratio of glacial acetic to concentrated acid is within the ratio of from 1:2 to 5:1. This acid component mixture is combined with from about 0.1% to about 5% by weight of soluble inorganic bromide or iodide salt.

Abstract: N-nitrosamines are reacted with a denitrosating agent to cleave the N-NO bond and yield nitric oxide which may be analyzed to determine both qualitatively and quantitatively, the N-nitrosamine content of a test sample. The denitrosating reagent has the advantage of being useful, even in the presence of substantial amounts of water, and comprises a mixture of glacial acetic acid and a concentrated inorganic acid which is either phosphoric acid or sulfuric acid. The volume ratio of glacial acetic to concentrated acid is within the ratio of from 1:2 to 5:1. This acid component mixture is combined with from about 0.1% to about 5% by weight of soluble inorganic bromide or iodide salt.

Abstract: N-nitrosamines are reacted with a denitrosating agent to cleave the N--NO bond and yield nitric oxide which may be analyzed to determine both qualitatively and quantitatively, the N-nitrosamine content of a test sample. The denitrosating reagent has the advantage of being useful, even in the presence of substantial amounts of water, and comprises a mixture of glacial acetic acid and a concentrated inorganic acid which is either phosphoric acid or sulfuric acid. The volume ratio of glacial acetic to concentrated acid is within the ratio of from 1:2 to 5:1. This acid component mixture is combined with from about 0.1% to about 5% by weight of soluble inorganic bromide or iodide salt.