A contrast chart device of the present invention comprises a contrast target presenting part for presenting a contrast target for a contrast sensitivity test at prescribed timing; a pupil data measuring part for producing an image of an anterior ocular segment of a subject and measuring the diameter or area of a pupil region in the anterior ocular segment; and a measurement timing forming part for forming timing at which the pupil data measuring part performs measurement.

A deoxo unit is operated with excess oxygen to produce high purity nitrogen from a partially purified stream passing from a membrane or pressure swing adsorption unit. Essentially complete fuel utilization is achieved in applications in which essentially oxygen-free nitrogen product is not required.

A method for removing nitrogen monoxide effectively from a nitrogen monoxide-containing gas which comprises contacting a nitrogen monoxide-containing gas with an aqueous solution containing a ferrous ion complex formed from a ferrous ion and an organic compound of 2 to 24 carbon atoms having in the molecule at least one atomic group selected from mercapto, amino, imino and nitrilo groups. When a sulfite or sulfide is present in the above aqueous solution, the nitrogen monoxide-absorbing capacity...

A method of treating a combustion exhaust gas containing nitrogen oxides comprises: A first step of removing nitrogen oxides by treating a mixture of the exhaust gas, oxygen and ammonia in the absence of hydrogen or in the presence of lower than 10 mole ratio of hydrogen to ammonia at a temperature from 700.degree. C to 1300.degree. C and A second step of adjusting a mole ratio of hydrogen to ammonia in the pretreated exhaust gas to higher than 3 and treating the mixed gas at a temperature from ...

Exhaust gases containing residual nitric oxide constituents from a processing operation are maintained at an elevated pressure, heated to from 260.degree. to 340.degree. C., and subjected to catalytic reduction with ammonia to produce purified exhaust gases. The pressure of the thus purified exhaust gases is then relieved in an expansion turbine.

A process for removing nitrogen oxides including nitrogen monoxide from a gaseous mixture such as industrial waste gases is provided. The gaseous mixture is contacted, first, with an aqueous solution of a chlorate and, then, with water, an aqueous solution or dispersion of a basic compound or an aqueous alkaline solution or dispersion of a reducing agent.

In order to examine a degree of monocular diplopia is easily examined in a quantitative manner, a plurality of circular eye marks are seen from a predetermined examination distance with a single eye of a patient to find a particular eye mark whose double vision images are observed to be circumscribed each other, and a degree of monocular diplopia is determined by a view angle of the relevant circular eye mark. Since the eye mark is formed as a circular pattern, a degree of monocular diplopia can...

This invention relates to catalysts and more particularly to the catalyst decomposition of one or more oxides of nitrogen present in a gas stream by contacting the gas with a catalyst comprising a compound of the formula A.sub.x B.sub.y, where A is selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Th, and U, B is selected from the group consisting of B, C, N and Si, x has a value 1.ltoreq.x.ltoreq.7 and y has a value 1.ltoreq.y.ltoreq.4.

This invention relates to catalysts and more particularly to the catalyst decomposition of one or more oxides of nitrogen present in a gas stream by contacting the gas with a catalyst comprising a compound of the formula A.sub.x B.sub.y, where A is selected from the group consisting of Tl, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Th, and U, B is selected from the group consisting of B, C, N and Si, x has a value 1.ltoreq.x.ltoreq.7 and y has a value 1.ltoreq.y.ltoreq.4.

A method for removing nitric oxide from gas streams containing same. The nitric acid is removed by contacting the nitric oxide with elemental iron in the presence of water. The nitric oxide is believed to be reduced to nitrogen gas. The method has particular applications to removal of nitric oxide from gas streams produced during combustion of carbonaceous materials.