Deterioration rapid

The deliquescent solid must be stored in a dry, tightly-stoppered container. If exposed to the air it deteriorates rapidly, developing an unpleasant odour. Samples that have been kept for some time are best recrystallised from absolute ethanol before use. 

Concretes. Concretes are produced by extraction of flowers, leaves, or roots, usually with hydrocarbon solvents. After removal of the solvent by distillation, the concrete is obtained as a thick, waxy residue. Such materials are used in some fine fragrances, but the waxes they contain can give rise to solubihty problems. Eor this reason, concretes are often dissolved in alcohol to make tinctures, or in other low odor diluents. Production of concretes, especially flower concretes, usually takes place where the botanicals are grown since the odors of such materials deteriorate rapidly after harvesting. 

Aminophenol. This compound forms white plates when crystallized from water. The base is difficult to maintain in the free state and deteriorates rapidly under the influence of air to pink-purple oxidation products. The crystals exist in two forms. The a-form (from alcohol, water, or ethyl acetate) is the more stable and has an orthorhombic pyramidal stmcture containing four molecules per unit cell. It has a density of 1.290 g/cm (1.305 also quoted). The less stable P-form (from acetone) exists as acicular crystals that turn into the a-form on standing they are orthorhombic bipyramidal or pyramidal and have a hexamolecular unit (15,16,24) (see Tables 3—5). 

Wood is widely used as a stmctural material in the chemical industry because it is resistant to a large variety of chemicals. Its resistance to mild acids is far superior to that of steel but not as good as some of the more expensive acid-resistant alloys. Wood tanks used to store cold, dilute acid have a relatively long service life. However, increasing concentration or temperature causes the wood tank to deteriorate rapidly (6). 

This requirement also makes good sense. A calibration is nothing more than a mathematical model that relates the behavior of the measureable data to the behavior of that which we wish to predict. We construct a calibration by finding the best representation of the fit between the measured data and the predicted parameters. It is not surprising that the performance of a calibration can deteriorate rapidly if we use the calibration to extrapolate predictions for... 

The salts of Na, Ba and Sr, used as oxidants and to impart appropriate flame colors, are w soluble. Excessive moisture content (over 0.5%) is deleterious in terms of light intensity, color saturation and burning duration. BlkPdr, a widely used ignition source and flame transfer agent, absorbs moisture and deteriorates rapidly. Many instances of pyrot no-fire incidents have been found to be the result of such deterioration (Refs 10,18,21 38)... 

Purchase salicylates in small amounts when used on an occasional basis. Keep the container tightly closed at all times because salicylates deteriorate rapidly when exposed to air, moisture, and heat. 

The synthetic data have been obtained by adding random noise with standard deviation of about 0.4 )0.g 1 to the theoretical plasma concentrations. As can be seen, the agreement between the estimated and the computed values is fair. Estimates tend to deteriorate rapidly, however, with increasing experimental error. This phenomenon is intrinsic to compartmental models, the solution of which always involves exponential functions. 

In addition to a large input dimension, complex processes also typically have a large output dimension (i.e., many possible plant behaviors). Although only a few events occur at any given time, identification of those few events requires consideration of a large subset of all possible events. Without careful management of both input and output dimensionality, interpretation performance deteriorates rapidly with scale and complexity. 

Equipment can reasonably be expected to perform to its full capability when new but may deteriorate rapidly in use unless properly maintained and calibrated. Maintenance of equipment can be either preventive or curative. Some simple maintenance will be possible by the user however, in many cases it will be the responsibility of the manufacturer, supplier or a recognized agent. Use of this professional maintenance may be a condition of the warranty, and do-it-yourself repairs may invalidate the warranty. 

Where facilities are exposed to the constant radiation of the sun, sun shades are provided over exterior exposed equipment that may not function properly at elevated temperatures or would deteriorate rapidly if left continual exposed to the direct sunlight. Most electrical or electronic equipment is rated for a maximum operating temperature of 40 °C (104 °F) unless otherwise specified, e.g., hazardous area lighting temperatures are normally specified for 40 °C (104 °F) limit. Of particular concern for fire protection systems are those containing storage for foam concentrates rubber hoses or other rubber components which may dry and crack. 

In one week in 1989 Ann s health deteriorated rapidly from MCS. Her medical career had abruptly ended nine months earlier when she sustained a back injury. She went from living an active, athletic life to living in the backseat of her Chevy Impala. Although her medical license is current she is still unable to practice medicine due to severe physical limitations. 

When the initial concentration of the merocyanine form is lower than the CMC of the spiropyran form, the change in surface tension is gradual all through the progression of photoreaction. The value of Ajjq/Acqq remains constant during photoirradiation. Unfortunately, reversibility of this photochromism is poor and the micelle formation/dissociation cycle deteriorates rapidly. 

This colorant is produced in the USA, where it also plays a minor role on the market. Its shade is a reddish yellow. P.Y.60 is used in trade sales paints and in emulsion paints. Poor resistance to organic solvents, lack of overcoating fastnesss, and a lightfastness that deteriorates rapidly with the degree of reduction with Ti02 are reasons for the limited commercial interest in this pigment. Crystal data are published by A. Whitaker [12],... 

Full shades of Toluidine Red are extremely lightfast and weatherfast, but deteriorate rapidly as the pigment is reduced with white pigment. In full shades, the lightfastness equals step 7 on the Blue Scale, while 1 4 Ti02 reductions only reach step 4. The pigment is therefore used preferably in full or similarly deep shades. Recommendations include emulsion paints for interior application or short-term advertisement and marking purposes. 

Another NIMH scientist went out on a limb, saying that it was incredible that marijuana in any natural or synthetic form could serve as a chemical warfare agent. THC itself, he said, deteriorates rapidly and is too bulky and expensive for such use. LSD is cheaper, more stable, and packs a bigger punch in a smaller dose. He added that one could readily introduce an easily carried quantity of LSD into the food or water supply of a major city, enough to alter radically the sense perceptions of its population for 12 to 24 hours. 

Limited testing on chlorine sensitivity of poly(ether/amidel and poly(ether/urea) thin film composite membranes have been reported by Fluid Systems Division of UOP [4]. Poly(ether/amide] membrane (PA-300] exposed to 1 ppm chlorine in feedwater for 24 hours showed a significant decline in salt rejection. Additional experiments at Fluid Systems were directed toward improvement of membrane resistance to chlorine. Different amide polymers and fabrication techniques were attempted but these variations had little effect on chlorine resistance [5]. Chlorine sensitivity of polyamide membranes was also demonstrated by Spatz and Fried-lander [3]. It is generally concluded that polyamide type membranes deteriorate rapidly when exposed to low chlorine concentrations in water solution. 

Performance vs Crosslinker Level. Table IV presents tensile and swell Index results on a series of approximately 0 C Tg VAE emulsion copolymers. ABDA containing copolymers had fair swell Index values which deteriorated rapidly as ABDA levels declined, but showed slow declines In wet tensile performance with reduced levels. Possible reasons for this are discussed below. 

---