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Measurements extreme conditions

Heterogeneous catalysts are more common. However, they degrade and need replacement. If contaminants in the feed material or recycle shorten catalyst life, then extra separation to remove these contaminants before the feed enters the reactor might be justified. If the cataylst is sensitive to extreme conditions, such as high temperature, then some measures can help to avoid local hot spots and extend catalyst life ... [Pg.279]

PPS is well-recognized for its exceptional chemical resistance. There are no known solvents for PPS below 200°C. A comprehensive survey of solvents for PPS has been published (115). Extreme conditions are required to dissolve PPS in both common and exotic solvents. Solution viscosity measurements are made difficult by this high temperature requirement. Inherent viscosity measurements are performed in 1-chloronaphthalene at 206°C at a concentration of 0.4 g of polymer per deciliter of solution. The inherent viscosity of PPS solutions shows a usefiil response to increa sing molecular weight. Table 2 shows a correlation of inherent viscosity measurements with melt flow measurements. [Pg.446]

This extreme condition rarely happens but serious peak distortion and loss of resolution can still result. This is particularly so if the sensor volume is of the same order of magnitude as the peak volume. The problem can be particularly severe when open tubular columns and columns of small diameter are being used. Scott and Kucera measured the effective sensor cell volume on peak shape and their results are shown in Figure 13. [Pg.307]

Los Alamos is processing a wide variety of residues, including Pu-Be neutron sources, polystyrene-Pu02-U02 blocks, incinerator ash, Pu-U alloys and oxides, Pu-Zr alloys and oxides, Pu-Np alloys and oxides, Pu-Th alloys and oxides, etc. Processes have been developed for these scrap items (see Figure 2), but we need to know more about Pu-Np separations Pu-Th separations oxalate precipitations for both plus 3 and plus 4 valences valence stabilization dissolution methods for high-fired impure oxides in-line alpha monitors to measure extremely low concentrations of Pu and Am in HNO3 solutions and solubility of various mixtures of Pu02 and UO2 under a variety of conditions. [Pg.356]

Electrolytes, like electronic conductors, obey Ohm s Law, except under such extreme conditions as those involving very high voltages and/or very high-frequency alternating currents. The conductance of an electrolyte is calculated from measurements of its resistance. [Pg.606]

The techniques used for handling various materials depend on their physical states as well as their chemical properties. While it is comparatively easy to handle liquids and solids, it is not as convenient to measure out a quantity of a gas. Fortunately, except under rather extreme conditions, all gases have similar physical properties, and the chemical identity of the substance does not influence those properties. For example, all gases expand when they are heated in a nonrigid container and contract when they are cooled or subjected to increased pressure. They readily diffuse through other gases. Any quantity of gas will occupy the entire volume of its container, regardless of the size of the container. [Pg.181]

Until now, Mercury has only been studied more closely by one spacecraft (Mariner 10, 1974), since its nearness to the sun means that spacecraft approaching it are subject to particularly extreme conditions. NASA s MESSENGER (Mercury Surface, Space, Environment, Geochemistry and Ranging) was launched in 2004 and is planned to reach Mercury in March 2011, and then to orbit the planet. The main tasks of the MESSENGER mission are to map the planet, to make measurements of its magnetic field and to collect data relevant to its geological and tectonic history (Solomon, 2007). [Pg.44]

Precision is the closeness of agreement between independent test results obtained under stipulated conditions. Precision depends only on the distribution of random errors and does not relate to the true value. It is calculated by determining the standard deviation of the test results from repeat measurements. In numerical terms, a large number for the precision indicates that the results are scattered, i.e. the precision is poor. Quantitative measures of precision depend critically on the stipulated conditions. Repeatability and reproducibility are the two extreme conditions. [Pg.57]

In this research, the main focus is safety in a chemical company handling hazardous substances. The risks of accidents or other events during processes involving hazardous substances (flammable, toxic, or explosive) or activities where extreme conditions are used (like high/low pressures or high/low temperatures), are subject of this research. Process safety is the absence of risk from events with these hazardous substances and activities with extreme conditions. Non-process safety or process risk is often measured by accidents, incidents and near misses and this concept will be discussed in the following sub-Section. [Pg.19]

The video installation as naked evidence of the extreme condition of time and culture unembellished by painting that would convey well-being and illusory calm, it is precisely the technological phenomenality of Vadim Kosmachev that manifests the critical point, the ultimate measure of the world, its ruinousness, its inflation and its splendid illusoriness. Its laminar nature conceals spatial paradoxes where confront the document and the reality of human presence in the... [Pg.80]

In Tables 5.10 and 5.11 the method conditions are represented by 0 and the extreme conditions by 1 and -1. The star design requires one measurement at each extreme value whereas the reflected design has two measurements. This difference becomes more marked for larger k values. Star designs can not test interaction effects. [Pg.210]

Last but not least, the construction of the windows, which make measurements under the mentioned extreme conditions possible, should be discussed (209). Figs. 6.4a and 6.4b give schematic representation of the windows used in the described apparatus. Both windows are cuvettes, each made from one piece of glass (BK 7, Schott Gen.), with a flat bottom which is polished on both sides. With the window mounted in the bottom of the rotor unit (Fig. 6.4 a) the cuvette (1) is used in a position in which the bottom is on the upper side. With its outer cylindrical... [Pg.298]


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