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Electrical history

In order to anticipate problems and to interpret observations under the extreme conditions of shock compression, it is necessary to consider structural and electronic characteristics of PVDF. Although the phenomenological piezoelectric properties of PVDF are similar to those of the piezoelectric crystals, the structure of the materials is far more complex due to its ferroelectric nature and a heterogeneous mixture of crystalline and amorphous phases which are strongly dependent on mechanical and electrical history. [Pg.104]

See also Electricity, History of Energy Economics Transportation, Evolution ofEnergy Use and. [Pg.280]

Brittain, J. E. (1977). Turning Points in American Electrical History. New York IEEE Press. [Pg.369]

See also Electric Power, Generation of Electric Power Transmission and Distribution Systems Electricity, History of Transformers. [Pg.394]

See also Consei vation of Energy Consumption, Culture and Energy Usage Economically Efficient Energy Edison, Thomas Alva Elctricity Electricity, History of Electric Power, Generation of Power. [Pg.719]

See also Ampere, Andre-Marie Clausius, Rudolf Julius Emmanuel Electricity Electricity, History of Faraday, Michael Gibbs, Josiah Willard Magnetism and Magnets Molecular Energy Oersted, Hans Christian Thomson, William. [Pg.783]

Heat capacities of polymer are complicated by physical and chemical structural changes, namely by changes in crystallinity, crystal structure, morphology, tacticity, molecular weight and copolymer unit content. Furthermore the picture can be complicated by changes in mechanical, thermal and possibly electrical history of the polymer. [Pg.356]

One of the most extensively studied pdymers of medium crystallinity is poly-(vinylidene fluoride). The interest in this polymer results from its use as a piezoelectrical and pyro-electrical material (Nakamura and Wada, 1971 Hiqrakawa and Wada, 1973 Murayama, 1975 Murayama and co-workers, 1975 Muiayama and Hashizume, 1976 Mopsik and Broadhurst, 1975). Many dielectric studies have been made and recent work includes that of Koizumi and co-workers (1969), Sasabe and co-workers (1969), Yano (1970), Kakutani (1970), Osaki and cowoikers(1971), Nakagawa and Ishida (1973), Uemura (1974), Osaki and Iriiida (1974), Yano and co-workers (1974) and Brereton and co-workers (1977). It is evid it from these and eadier studies that the dielectric behaviour of this polymer is one of the most complex of the linear polymer systems. Studies have been made of samples of different (i) ciystal forms, (ii) orientations, (iii) crystallinity, (iv) thermal and electrical histories. At least four relaxation regions are observed, being labelled here as a, Oc,... [Pg.82]

A general prerequisite for the existence of a stable interface between two phases is that the free energy of formation of the interface be positive were it negative or zero, fluctuations would lead to complete dispersion of one phase in another. As implied, thermodynamics constitutes an important discipline within the general subject. It is one in which surface area joins the usual extensive quantities of mass and volume and in which surface tension and surface composition join the usual intensive quantities of pressure, temperature, and bulk composition. The thermodynamic functions of free energy, enthalpy and entropy can be defined for an interface as well as for a bulk portion of matter. Chapters II and ni are based on a rich history of thermodynamic studies of the liquid interface. The phase behavior of liquid films enters in Chapter IV, and the electrical potential and charge are added as thermodynamic variables in Chapter V. [Pg.1]

This subject has a long history and important early papers include those by Deijaguin and Landau [29] (see Ref. 30) and Langmuir [31]. As noted by Langmuir in 1938, the total force acting on the planes can be regarded as the sum of a contribution from osmotic pressure, since the ion concentrations differ from those in the bulk, and a force due to the electric field. The total force must be constant across the gap and since the field, d /jdx is zero at the midpoint, the total force is given the net osmotic pressure at this point. If the solution is dilute, then... [Pg.180]

The focus of this section is the emission of ultraviolet and visible radiation following thermal or electrical excitation of atoms. Atomic emission spectroscopy has a long history. Qualitative applications based on the color of flames were used in the smelting of ores as early as 1550 and were more fully developed around 1830 with the observation of atomic spectra generated by flame emission and spark emission.Quantitative applications based on the atomic emission from electrical sparks were developed by Norman Lockyer (1836-1920) in the early 1870s, and quantitative applications based on flame emission were pioneered by IT. G. Lunde-gardh in 1930. Atomic emission based on emission from a plasma was introduced in 1964. [Pg.434]

A comprehensive history of ferrous scrap recycling ia the United States beginning ia 1646 has beea pubUshed (3). Some selected eveats of iaterest iaclude the first opea-hearth steel produced (1868) the first commercial direct-arc electric furnace steel produced ia the United States (1906) the first large iaduction furnace iastaHed ia the United States (1914) the first basic oxygen steel produced ia the United States (1954) the rise of continuous casters and scrap-based minimills (1965) the first thin-slab continuous caster at a minimill (1989) U.S. exports and imports of ferrous scrap at record highs (1990) and the end of production of open-hearth steel (1991). [Pg.552]

Natural resins have been collected by hand throughout recorded history and used with minimal processing. They are reported to have been used in the arts, both in paints and for polishing sculptures, as early as 350 BC. Amber, the hardest of these resins, has been used as a gemstone from early Greek history to modem times. The electrical properties of amber were first recorded about 300 BC. Following is a description of commercial natural resins that are available in the United States. [Pg.140]

A minimum of 10 to 35 parts carbon black to 100 parts of mbber is required to obtain a resistivity in the order of 10 Q-cm. At that loading the carbon black particles, which have an average radius of 10 nm, form grapelike aggregates that provide continuous paths for the electrical current. Special purpose mbbers containing even more carbon black have resistances as low as 1 Q-cm (129). The electrical resistivity of mbber with carbon black is sensitive to strain history, probably because of temporary dismptions of the continuity of the carbon black aggregates. [Pg.296]

Electrical Properties. The electrical properties of siUcon carbide are highly sensitive to purity, density, and even to the electrical and thermal history of the sample. [Pg.465]

Physical Properties. Most of the physical properties discussed herein depend on the direction of measurement as compared to the bedding plane of the coal. Additionally, these properties vary according to the history of the piece of coal. Properties also vary between pieces because of coal s britde nature and the crack and pore stmcture. One example concerns electrical conductivity. Absolute values of coal sample specific conductivity are not easy to determine. A more characteristic value is the energy gap for transfer of electrons between molecules, which is deterrnined by a series of measurements over a range of temperatures and is unaffected by the presence of cracks. The velocity of sound is also dependent on continuity in the coal. [Pg.221]

In Ancient Rome, Pliny the Elder (c. a.d. 23-79) dedicated 37 volumes of Natural History to the emperor Titus. In the last of these books, dealing with gems and precious stones, he describes the properties of the fossil resin, amber. The ability of amber to attract dust was recognised and in fact the word electricity is derived from elektron, the Greek for amber. [Pg.2]

Some materials are able to withstand quite lengthy thermal histories , a term loosely used to describe both the intensity (temperature) and the duration of heating. Polyethylene and polystyrene may often be reprocessed a number of times with little more than a slight discoloration and in the case of polyethylene some deterioration in electrical insulation properties. [Pg.163]


See other pages where Electrical history is mentioned: [Pg.394]    [Pg.1007]    [Pg.227]    [Pg.180]    [Pg.533]    [Pg.538]    [Pg.641]    [Pg.394]    [Pg.1007]    [Pg.227]    [Pg.180]    [Pg.533]    [Pg.538]    [Pg.641]    [Pg.441]    [Pg.100]    [Pg.329]    [Pg.511]    [Pg.93]    [Pg.337]    [Pg.38]    [Pg.347]    [Pg.441]    [Pg.400]    [Pg.88]    [Pg.88]    [Pg.107]    [Pg.504]    [Pg.237]    [Pg.342]    [Pg.363]    [Pg.55]    [Pg.399]    [Pg.391]    [Pg.127]   
See also in sourсe #XX -- [ Pg.227 ]




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