Paper testing

Place 130 ml. of concentrated hj drochloric acid in a 1 - 5 litre round-bottomed flask, equipped ith a mechanical stirrer and immersed in a freezing mixture of ice and salt. Start the stirrer and, when the temperature has fallen to about 0°, add 60 g. of finely-crushed ice (1), run in 47 5 g. (46 5 ml.) of pure aniline during about 5 minutes, and then add another 60 g. of crushed ice. Dissolve 35 g. of sodium nitrite in 75 ml. of water, cool to 0-3°, and run in the cold solution from a separatory funnel, the stem of which reaches nearly to the bottom of the flask. During the addition of the nitrite solution (ca. 20 minutes), stir vigorously and keep the temperature as near 0° as possible by the frequent addition of crushed ice. There should be a slight excess of nitrous acid (potassium iodide-starch paper test) at the end of 10 minutes after the last portion of nitrite is added. 

In a 30 minute test the results obtained should not differ by more than 1 minute using different lots of paper. On being exposed to nitric oxide fumes, these papers slowly turn green, followed by a salmon pink coloration Methyl Violet Paper Test (Field Test for Pro pint Powders). This method of testing proplnts using 0.1N methyl violet paper directly in the containers in which the powder is stored, was developed at Picatinny Arsenal in 1928—29 (Refs 1 2), and was adopted by the Ordnance Dept to replace the Observation Test about 1931... 

This applied particularly to double-base propints, although some single-base propints also gave erratic results. For these reasons, work was undertaken at Picatinny Arsenal to find an indicator that would be more reliable than methyl violet. About 60 commercially available dyes were examined by S. Helf (Ref 5) in exptl indicator paper tests, of which only three were found to be superior to methyl violet benzoazurine, trypan red and ethyl violet. Laboratory and surveillance testing showed that papers prepd with a 0.1% soln of benzoazurine did not change in color after one year when used with stable double-base propint, while methyl violet paper was bleached in nearly every case. The other two indicators mentioned above, trypan red and ethyl violet, were not as satisfactory as benzoazurine, although they were better than methyl violet. 

Methyl Violet Paper Test for Double-Base Powders , PATR 1652 (1947) 5) S. Helf,... 

The present paper tests the assumed original and enhancement mechanisms with rates and conversions for a broad range of contaminants measured under a fixed mass concentration (50 mg/m ) feed condition. The plots compared are reaction rates vs. (1) dark adsorption, Ot. (2) second order rate constant for (OH ) (TCE absent) or (Cl ) (TCE present), and (3) the product of these gas phase second order rate constant times the reactant dark coverage. Where a second order gas phase rate constant was not available, we estimated its value from correlations of kci vs. koH for tke same class of compounds. 

Budantsev, A. Yu. and Budantseva, T.A. (2005). Photometric analysis of paper tests using microplate readers. Journal of Analytical Chemistry (Russsian) 60 794-797. 

Hayes (1938) Measurement of Grains (pp 28-29) Compression Test (29) Stability by Kl-Starch Paper Test, 134.5°C Heat Test, 120°C Heat Test, 65.5°C Surveillance Test and Observation Test (29-30) Ballistic Test (30-31) Heat of Explosion at Constant Pressure (51-2) Volume of Gas (52-3) Heat of Explosion at Constant Volume (54-5) Potential (55) Temperature of Explosion (55-7) Pressure of Explosion (57-61) Heat of Explosion of Propellants (62-4) Ignition of Propellants (68-70) Mode and Rate of Burning (70-71) Velocity Measurements by Le Boulange, Aberdeen, and Solenoid Chronographs (84-92) Pressure Measurements by Crusher and Piezoelectric Gages (92-6)... 

A 5.5 M solution of bromine in dichloromethane is added dropwise to a vigorously stirred mixture of 19.1 g. (0.097 mole) of hydrazine 1, 75 ml. of dichloromethane, 75 ml. of water, and 22 g. (0.262 mole) of sodium bicarbonate in a 250-ml. flask, until a persistent, positive potassium iodide-starch paper test is obtained (Note 8). Excess bromine is then discharged with aqueous sodium sulfite, and the phases are separated. The aqueous phase is extracted with two 50-ml. portions of dichloromethane, and the combined organic extracts are washed with 30 ml. of water, dried over magnesium sulfate, filtered, concentrated using a rotary evaporator, and distilled to afford 17.3 g. (93% yield) of the diazene 2 as a clear, bright yellow oil, b.p. 95-97° (0.2 mm.) (Note 7). 

Preparation of Plastic Sulphur. Heat sulphur until it boils and pour it out in a thin stream into a crystallizer with cold water. Extract the solid substance from the water and dry it between sheets of filter paper. Test the ductility of the sulphur and its solubility in chloroform. Keep part of the sulphur for the next lesson and again study its physical properties. What molecules does plastic sulphur consist of ... 

A stirred soln of H-L-Phe(4-NH2)-OH (21 54 g, 300 mmol) in 4 M HC1 (600 mL) was cooled in a MeOH/ ice bath and treated slowly with aq NaN02 (20.7 g, 300 mmol). The mixture was kept for 1 h under vacuo (until negative to HN02 in the starch-iodine paper test). The soln of the diazonium salt was mixed slowly into 20% HC1 (400 mL) containing CuCl (10 g) and Cu powder (3g). After the cessation of gas release, the mixture was left overnight at 4 °C, the precipitate was filtered off (53 g of hydrochloride) and the filtrate was concentrated under vacuo and filtered again (9.2g) combined yield 61.2g (86%). 

Small funnel and qualitative grade filter paper Test tubes, 100 X 12 mm Microcapillaries or tapered capillaries Anhydrous sodium sulfate, Na2S04 UV-VIS spectrophotometer Glass cuvettes, 3 or 1 mL Materials for paper chromatography ... 

Approximately one hour of pencil-and-paper tests were administered at this time. Subjects were told that they would take a similar battery during the experimental session. To insure that the problems to be worked on were appropriate for the purpose, each participant was asked to present his selection briefly. By the end of the preparation session, participants were generally anticipative and at ease. They had been given a clear picture of what to expect, as well as information on how to cope with any difficulties that might arise. 

Gas Colour (odour) Effect of moist indicator paper Test... 

It is important to remember that a computer-adaptive test (CAT) is tailored to your performance level. The test will begin with a question of medium difficulty. Each question that follows is based on how you responded to earlier questions. If you answer a question correctly, the next question will be more difficult. If you answer a question incorrectly, the next question will be easier. The test is designed to analyze every answer you give as you take the test to determine the next question that will be presented. This is done to ascertain a precise measure of your quantitative abilities, using fewer test questions than traditional paper tests would use. 

In summary, the necessary assumptions to estimate paleoaltitude are that the surface moist static energy is invariant with longitude and that the moist enthalpy is a measurable quantity for the regional paleoclimate. The remainder of this paper tests these two assumptions and quantifies each error source. Given that previous work uses paleobotanical data, the second requirement implies that moist enthalpy must be accurately estimated from extant or newly discovered paleobotanical collections. 

Lead acetate paper test. A paper moistened with lead acetate solution turns black due to the formation of lead sulfide on exposure to H2S. 

Blotter test. This involves putting a spot of oil onto a piece of absorbent paper then heating it to allow the oil to spread. The darkness of the developed spot gives an indication of the amount of soot while the extent to which it travels indicates the state of dispersion. The paper test is qualitative, but can be quantified photometrically. 

Selenium tone for 5 minutes. The dilution will vary depending on the paper. The first time you work with a new paper test the first print in a dilution of 1 19. Have an identical wet but untoned print to compare against. If a color shift occurs try a 1 29 dilution, then 1 39 if necessary. Color shifts will usually be observed at about the 3 minute mark. 

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