Organic physical tests

The performance of organic finishes on test is evaluated by visual observation and by physical tests made upon coated specimens that have been exposed for various periods of time to natural or accelerated weathering conditions. Electrical tests are sometimes used on immersed specimens. 

Among the endocrine organs, the testes are unique because they are suspended in a tissue pouch outside of the body cavity. The testes can be felt and these organs are vulnerable to physical insults, either deliberate or accidental. The effects of castration were described by Aristotle over three hundred years B.C. Removal of the testes or castration as a form of punishment or tribute dates to antiquity. Domestic animals and some cases humans were castrated to make them more docile. Castrata were valued as harem keepers. In addition, seasonal changes in behavior and the dramatic anatomical and behavioral events associated with puberty were components of the natural world (Bronson and Heideman, 1994). Thus, an awareness of a relationship between the testes and human behavior predates written history. 

A number of physical tests emphasizing stress-strain behavior will be covered in Chapter 14. Here, we will concentrate on other areas of testing, emphasizing thermal and electrical properties and on the characterization of polymers by spectral means. Spectroscopic characterization generally concentrates on the structural identification of materials. Most of these techniques, and those given in Chapter 14, can also be directly applied to nonpolymeric materials such as small organic molecules, inorganic compounds, and metals. 

United States Environmental Protection Agency (1982b) Method 8240. GC/MS method for volatile organics. In Test Methods for Evaluating Solid Waste—Physical/Chemical Methods, 2nd Ed. (US EPA No. S W-846), Washington DC, Office of Solid Waste and Emergency Response... 

Traditionally, lubricant property (performance) test methods were used to determine in-service fluid condition. A variety of industrial organizations have standardized a number of physical test methods for this purpose. Utilizing lubricant property tests for condition monitoring introduces several physical and economic problems ... 

The main purpose of this chapter is to provide information about the committees of the International Organization for Standardization (ISO) that produce and are responsible for all international standards on polymers, including the physical testing of polymers. In order to put this information into a wider perspective, the first part of the chapter gives a brief history of international standardization, describes the aims and structure of the ISO. the preparation and types of international standards, aspects of regional standardization, and the membership of the ISO. 

Exposure to living organisms is a biological rather than a physical test and is normally entrusted to specialist laboratories. A British standard for pipe joint rings [4] includes a requirement for resistance to microbiological degradation, and there is an ISO standard for re,sistance of plastics to fungi and bacteria (5). 

Color is one of the more useful properties for identifying substances without doing any chemical or physical tests. A violet vapor, for example, is characteristic of iodine. A red/brown gas could well be bromine or nitrogen dioxide (NOj) a practiced eye can distinguish between the two. Just a small amount of potassium permanganate (KMn04> in solution provides an intense purple color. A characteristic yellow/brown color in water may be indicative of organically bound iron. 

The ability to identify organic compounds is an important skill that is frequently used in the organic laboratory. Although there are several spectroscopic methods and many chemical and physical tests that can be used for identification, the goal of this experiment is to identify an unknown liquid using infrared spectroscopy and a boiling-point determination. Both methods are introduced in this experiment. 

Loading plastics with biological organisms is more a biological than a physical test and is usually performed in dedicated laboratories. 

In any systematic method for the identification of organic compounds, both physical and chemical properties are utilized for locating the class, or, preferably, the homologous series to which the unknown belongs, and subsequently specific physical tests are applied to locate the individual within the series. Unfortunately for organic analysis, the study of the relationship between physical properties and molecular structure is still a relatively undeveloped field, certainly so when viewed from the standpoint of potential possibilities. 

The saturated aliphatic hydrocarbons comprise the class of organic compounds most resistant toward the usual chemical reactions the preparation of characteristic derivatives is therefore a difficult matter. Moreover, this class of compounds is not ordinarily met in the form of individuals but rather in the form of complex mixtures, as, for example, in the various fractions from petroleum. Final tests applied in the identification of paraffin hj drocarbons, therefore, consist in the application of a variety of physical tests, such as boiling-point range, siX cifie gravity, refractive index, etc. Preliminary work, of course, must conclusively demonstrate the absence of appreciable amounts of compounds other than paraffin hydrocarbons. 

The United States Federal Food and Drug Administration (FDA) regulations require the complete characterization of drug compounds. Since most pharmaceutical agents are organic compounds, much of this characterization involves various chromatography-based analytical techniques, as well as NMR, IR and various physical testing methods (such as DSC, TGA and XRD). The field of atomic spectroscopy has not traditionally played a major role in the characterization of pharmaceutical products, but on closer inspection it is clear that absorption and emission spectroscopic techniques can play a valuable role... 

Some Physical Properties of Some Organic Solvents (Tested at 25°C Unless Otherwise Indicated) ... 

This semiquantitative method for the analysis of mixtures of nonvolatile organic or inorganic substances combines a simple means for separating the constituents of the dissolved mixture with their detection by the application of chemical and physical tests. ... 

The validation of the prediction equation is its performance in predicting properties of molecules that were not included in the parameterization set. Equations that do well on the parameterization set may perform poorly for other molecules for several different reasons. One mistake is using a limited selection of molecules in the parameterization set. For example, an equation parameterized with organic molecules may perform very poorly when predicting the properties of inorganic molecules. Another mistake is having nearly as many fitted parameters as molecules in the test set, thus fitting to anomalies in the data rather than physical trends. 

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