Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Masks function testing

However, like other methods of test to be discussed in the following section, the salt formation with pyridine hydrohalides in the control of completed amino acylation of amino groups unfortunately interferes in the peptide synthesis with masking functions labile to acid [133] and — as already mentioned — with other basic centres on polymer like guanidyl, indolyl, and imidazolyl residues. [Pg.43]

Pulmonary function testing has revealed more obstructive patterns than restriction, and approximately half of these obstructive spirometric results are reversible in response to inhaled bronchodilators. FVC, FEVl, and FEVl/FVC (FEV1%) have all been foimd to be significantly lower in SM-intoxicated veterans in comparison with healthy nonexposed subjects and CWA survivors who had used a gas mask at the time of attack (Balali-Mood, 1992 Balali-Mood and Hefazi, 2005 Balali-Mood et al., 2005a,b Ghanei and Adibi, 2007). [Pg.41]

Initial evaluations of chemicals produced for screening are performed by smelling them from paper blotters. However, more information is necessary given the time and expense required to commercialize a new chemical. No matter how pleasant or desirable a potential odorant appears to be, its performance must be studied and compared with available ingredients in experimental fragrances. A material may fail to Hve up to the promise of its initial odor evaluation for a number of reasons. It is not at all uncommon to have a chemical disappear in a formulation or skew the overall odor in an undesirable way. Some materials are found to be hard to work with in that their odors stick out and caimot be blended weU. Because perfumery is an individuaHstic art, it is important to have more than one perfumer work with a material of interest and to have it tried in several different fragrance types. Aroma chemicals must be stable in use if their desirable odor properties are to reach the consumer. Therefore, testing in functional product appHcations is an important part of the evaluation process. Other properties that can be important for new aroma chemicals are substantivity on skin and cloth, and the abiHty to mask certain malodors. [Pg.84]

Between 1955 and 1965, 147 human subjects underwent exposure to H at Edgewood. One hundred sixteen masked subjects had aerosol chamber exposures to test the effectiveness of various protective garments. Equipment was tested for leaks with chloropicrln exposures before H exposures. Subjects underwent up to 14 exposures to H on different days and were removed from the tests when dermal erythema indicated garment leakage. Some tests simulated tropical or windy conditions, and others simulated battlefield functions. Thirty-one subjects had cutaneous exposures to test the effectiveness of antidotes or treated cloths or for sensitization. [Pg.124]

From 1955 to 1971, 136 subjects underwent one or two experimental exposures to PS in equipment tests. The subjects remained in a test chamber for up to 4 h with gas masks in place and sometimes simulated battlefield functions. [Pg.224]

Exposure to aluminum is usually not harmful. Aluminum occurs naturally in many foods. Factory workers who breathe large amounts of aluminum dusts can have lung problems, such as coughing or changes that show up in chest X-rays. The use of breathing masks and controls on the levels of dust in factories have eliminated this problem. Some workers who breathe aluminum dusts or aluminum fumes have decreased performance in some tests that measure functions of the nervous system. Some people who have kidney disease store a lot of aluminum in their bodies. The kidney disease causes less aluminum to be removed from the body in the urine. Sometimes these people developed bone or brain diseases that doctors think were caused by the excess aluminum. Some studies show that people exposed to high levels of aluminum may develop Alzheimer s disease, but other studies have not found this to be true. We do not... [Pg.24]

Recently, the reaction of masked ortho-benzoquinone [92] with C60 was tested [93]. The [4+2] cycloaddition reaction of such electron-deficient dienes with fullerenes resulted in the formation of highly functionalized bicyclo [2.2.2] octenone-fused fullerenes. The reactants were generated in situ by the oxidation of the readily available 2-methoxy phenols with hypervalent iodine agents. For the several different masked ortho-benzoquinones that were tested, it was found that the yield of the cycloadducts depends on the nature of the starting materials and the reaction conditions. Other Diels-Alder reactions of such electron-deficient dienes with electron-poor fullerenes involved tropones [94], 1,3-butadienes substituted with electron-withdrawing groups [95], and 2-pyrone [96]. [Pg.9]

The ultimate resolution that can be obtained with a Vidicon-tube system can best be seen from the manufacturers specification. The spatial resolution is expressed by the so called modulation-transfer function (MTF), which is measured by the projection of a test mask directly on the photocathode, with visible light. Of course, this test does not include the degradation by the phosphor screen in X-ray applications. [Pg.86]

For single exponential decay functions with reasonably long decay times (> 2 ns) deconvolutkm poses few difficulties. Double exponent decays, for which G(t) contains 4 variable parameters, are much more difficult to analyse correctly and a number of tests have been proposed to ensure that the fitting procedure does not mask distortions in the data or the presence of a further component. The most common of these tests is a plot of the weighted residuals, which should be randomly distributed about zero. Also of use is a plot of the autocorrelation function of the resid-uals . ... [Pg.94]

The ability of a solder mask to protect conductors from physical and chemical deterioration and to insulate adjacent circuitry is a major consideration of PCB manufacturers. The Institute for Interconnecting and Packaging Electronic Circuits (IPC) has defined the requirements for the qualification and performance of solder masks in the Standard Specification IPC-SM-840 (A). The specification defines classes (1, 2, and 3) to reflect progressive increases in sophistication, functional performance, and testing methods. These classes try to provide PCB manufacturers with assurances of reliability. For example, Class 1 requirements provide the reliability needed by commercial boards used in radios, televisions, and small appliances. Class 2 is for computers and Class 3 for military and life-dependent products. [Pg.367]


See other pages where Masks function testing is mentioned: [Pg.37]    [Pg.53]    [Pg.351]    [Pg.186]    [Pg.229]    [Pg.325]    [Pg.325]    [Pg.1295]    [Pg.432]    [Pg.329]    [Pg.148]    [Pg.205]    [Pg.98]    [Pg.130]    [Pg.80]    [Pg.47]    [Pg.489]    [Pg.329]    [Pg.805]    [Pg.631]    [Pg.38]    [Pg.327]    [Pg.235]    [Pg.592]    [Pg.128]    [Pg.145]    [Pg.2910]    [Pg.223]    [Pg.1729]    [Pg.495]    [Pg.266]    [Pg.234]    [Pg.100]    [Pg.188]    [Pg.97]    [Pg.16]    [Pg.28]    [Pg.229]    [Pg.86]    [Pg.225]   
See also in sourсe #XX -- [ Pg.365 , Pg.403 ]




SEARCH



Functional testing

Functional tests

Test function

© 2024 chempedia.info