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McGraw Hill Financial, Inc. is an American publicly traded corporation headquartered in Rockefeller Center in New York City. Its primary areas of business are financial, publishing, and business services.
A set of related signal processing techniques for remote sensing that involve matching measured signals obtained from an array of sensors to synthesized signals obtained from signal propagation simulations conducted in a model of the actual environment. Here the signals are typically acoustic or electromagnetic waves, but they may be water waves, seismic waves, structural waves, or any other measurable phenomenon that travels in a predictable manner from its source to a distant receiver. Matched-field processing is the extension of elementary sensor-array signal processing techniques for line-of-sight signal propagation in uniform unbounded environments to complicated, but predictable, signal propagation in nonuniform bounded environments. Matched-field processing is superior to these elementary techniques because it can explicitly account for reflection, refraction, and scattering of the signal as it propagates from its source to the sensors. However, this superior performance is possible only when the signal propagation simulations are accurate and the model environment matches the environment in which the signal propagation took place.
Industry:Science
A set of rigid bodies, called links, joined together at pivots by means of pins or equivalent devices. A body is considered to be rigid if, for practical purposes, the distances between points on the body do not change. Linkages are used to transmit power and information. They may be employed to make a point on the linkage follow a prescribed curve, regardless of the input motions to the linkage. They are used to produce an angular or linear displacement <i>f</i>(<i>x</i>), where <i>f</i>(<i>x</i>) is a given function of a displacement <i>x</i>.
Industry:Science
A set of techniques whereby a sequence of information-carrying quantities occurring at discrete instances of time is encoded into a corresponding regular sequence of electromagnetic carrier pulses. Varying the amplitude, polarity, presence or absence, duration, or occurrence in time of the pulses gives rise to the four basic forms of pulse modulation: pulse-amplitude modulation (PAM), pulse-code modulation (PCM), pulse-width modulation (PWM, also known as pulse-duration modulation, PDM), and pulse-position modulation (PPM).
Industry:Science
A severe diarrheal disease caused by infection of the small bowel of humans with <i>Vibrio cholerae</i>. This facultatively anaerobic, curved, gram-negative, rod-shaped bacterium is rapidly motile by means of a single sheathed polar flagellum. Cholera is transmitted by the fecal-oral route. From its ancestral home in the Indo-Pakistani subcontinent, through movement of people by ships and other means of transportation, cholera has swept the world in seven pandemic waves. These involved the Western Hemisphere several times in the 1800s, and again in Peru in 1991. Whereas previous cholera outbreaks were associated with high mortality rates, through understanding of its pathophysiology it can now be said that no one should die of cholera who receives appropriate treatment soon enough.
Industry:Science
A severe inflammation of the lungs (pneumonia) commonly seen in North American cattle after experiencing the stress of transport. This disease occurs mainly in 6–9-month-old beef calves transported to feedlots. Many infectious agents, both viruses and bacteria, cause symptoms of respiratory disease in stressed cattle. However, the characteristic shipping fever pneumonia is caused primarily by the bacteria <i>Mannheimia</i> (formerly <i>Pasteurella</i>) <i>haemolytica</i> serotype A1 and, to a lesser extent, <i>Pasteurella multocida</i>; thus a synonym for shipping fever is bovine pneumonic pasteurellosis.
Industry:Science
A sexually transmitted infection of humans caused by <i>Treponema pallidum</i> ssp. <i>pallidum</i>, a corkscrew-shaped motile bacterium (spirochete). Due to its narrow width, <i>T. pallidum</i> cannot be seen by light microscopy but can be observed with staining procedures (silver stain or immunofluorescence) and with dark-field, phase-contrast, or electron microscopy. <i>Treponema pallidum</i> cannot be continuously cultured in vitro by standard bacteriological methods. For antigen production and experimental studies, the organism is propagated by inoculation of laboratory rabbits. Limited multiplication of <i>T. pallidum</i> has been obtained in a tissue culture system at a temperature of 91–95°F (33–35°C) in an atmosphere containing 1–5% oxygen and in media containing reducing agents. The organism is very sensitive to environmental conditions and to physical and chemical agents. The complete genome sequence of the <i>T. pallidum</i> Nichols strain (1.13 × 10<sup>6</sup> base pairs) has been determined. Analysis of the nucleotide sequence of the small, circular treponemal chromosome indicates that <i>T. pallidum</i> lacks the genetic information for many of the metabolic activities found in other bacteria. Thus, this spirochete is dependent upon the host for most of its nutritional requirements.
Industry:Science
A shallow, reinforced-concrete structural member that is very wide compared with depth. Spanning between beams, girders, or columns, slabs are used for floors, roofs, and bridge decks. If they are cast integrally with beams or girders, they may be considered the top flange of those members and act with them as a T beam.
Industry:Science
A shift toward longer wavelengths of spectral lines emitted by atoms in strong gravitational fields. It is also known as the Einstein shift. One of three famous predictions of the general theory of relativity, this shift results from the slowing down of all periodic processes in a gravitational field. The amount of the shift is proportional to the difference in gravitational potential between the source and the receiver. For starlight received at the Earth the shift is proportional to the mass of the star divided by its radius. In the solar spectrum the shift amounts to about 0.001 nanometer at a wavelength of 500 nanometers. In the spectra of white dwarfs, whose ratio of mass to radius is about 30 times that of the Sun, the shift is about 0.03 nm, which can easily be measured if it can be separated from the Doppler effect. This was first done by W. S. Adams for the companion of Sirius, a white dwarf whose true velocity relative to the Earth can be deduced from the observed Doppler effect in the spectrum of Sirius. The measured shift agreed with the prediction based on Einstein's theory and on independent determinations of the mass and radius of Sirius B. A more accurate measurement was carried out in 1954 by D. M. Popper, who measured the gravitational redshift in the spectrum of the white dwarf 40 Eridani B. Similar measurements, all confirming Einstein's theory, have since been carried out for other white dwarfs. Attempts to demonstrate the gravitational redshift in the solar spectrum have thus far proved inconclusive, because it is difficult to distinguish the gravitational redshift from so-called pressure shifts resulting from perturbations of the emitting atoms by neighboring atoms.
Industry:Science
A ship designed to break floating ice. Icebreaker technology has evolved rapidly since the 1960s as a result of potential resource development in the Arctic regions of Russia, Canada, and the United States. This led to the construction of icebreaking ships that can transit to all areas of the world, including the North Pole. The Arctic Ocean and Antarctica play a large role in shaping the global climate. With the Arctic Ocean and the ice-covered waters of Antarctica being the least studied of all the oceans, icebreakers provide the platforms from which polar science and research can be conducted on a year-round basis. On August 22, 1994, the first U. S. and Canadian icebreakers, USCGC <i>Polar Sea</i> and CCGS <i>Louis S. St. Laurent</i>, arrived at the North Pole after having conducted scientific research in areas never previously studied.
Industry:Science
A ship specifically configured for carrying passengers between two points. It permits persons to make their way from one place to another across a body of water, and it may carry vehicles, including commercial vehicles. A ferry is distinct from a cruise ship or a cargo ship. For a cruise ship the voyage itself is the destination, whereas with a ferry the journey's end point is the destination. While a ferry may carry cargo, in contrast to a cargo ship, this cargo is contained in a commercial vehicle accompanied by a driver.
Industry:Science
