Coordinated Universal Time

NIST F-l, which is now the official clock in the United States, provides the extremely accurate timekeeping necessary for modern technology-based operations. NIST F-l is also in the pool of atomic clocks used to define Coordinated Universal Time (known as UTC), the official world time. ... 

United States Pharmacopeia universal time coordinated universal time uridine 5 -triphosphate ultraviolet volt valine... 

Coordinated Universal Time (UTC) follows International Atomic Time (TAl) exactly except for an integral number of seconds, presently 32. These leap seconds are inserted on the advice of the International Earth Rotation Service (lERS) to ensure that, on average over the years, the sun is overhead within 0.9 s of 12 00 00 UTC on the meridian of Greenwich. UTC is thus the modern successor of Greenwich Mean Time, GMT, which was used when the unit of time was the mean solar day. 

More recent procednres of objective analysis practiced at most of the operational forecasting centers consist of the steps schematically described in Fig. 2. Most observed data are collected worldwide every 6 hours, say 00,06,... UTC (Coordinated Universal Time), and are blended into forecast values appropriate to the map time by the process referred to as data assimilation. The basic process of data assimilation, indicated by the boxenclosed by dashed lines in Fig. 2, consists of two steps One is objective analysis and the other is called initialization, which will be detailed in the next subsection. 

Accuracy Degree to which the pulse or signal measured by a particular clock conforms to a reference pulse or signal, such as coordinated universal time. The opposite of accuracy is drift. 

Coordinated Universal Time (UTC) UTC, an atomic time scale, is the basis for civil time. It is occasionally adjusted by one-second increments to ensure that the difference between the uniform time scale, defined by atomic clocks, does not differ from the earth s rotation by more than 0.9 sec. Differential A technique used to improve radionavigation system accuracy by determining positioning error at a known location and subsequently transmitting the determined error, or corrective factors, to users of the same radionavigation system, operating in the same area. 

Coordinated Universal Time (UTC) The time scale, maintained by the BIH (Bureau International de I Heure), that forms the basis of a coordinated dissemination of standard frequencies and time signals. 

Coordinated Universal Time (UTC) runs at the same rate as TAI. However, it differs from TAI by an integral number of seconds. This difference increases when leap... 

The assumptions on which the model rests are too crude to be realistic. In particular, the assumption of a universal time coordinate directly contradicts the basis of general relativity. To avoid the problem de Sitter repeated the calculation based on relativistically curved space-time, with the surprising result of an empty universe with variable radius. The traditional interpretation of this result as an expanding universe is not unique. It could just as well imply space-time with continuous curvature, characteristic of projective space. In the event, both solutions were soon superseded by an expanding-universe cosmology based on a Doppler interpretation of galactic redshifts. 

The predicted de Sitter expansion of empty space should not be interpreted as a property of the universe. The Einstein-de Sitter model describes another non-equilibrium situation in the form of an expanding material imi-verse with a universal time coordinate, orthogonal to a flat 3-dimensional subspace. The tendency here would be to restore equilibrium by spreading the excess density in order to match the pseudo-Euclidean geometry. 

The findings of Newton and Descartes developed into a beautiful model of space-time that served both microphysics and celestial mechanics convincingly well until the end of the nineteenth century. This scheme recognized the three-dimensional aspect of space that extends uniformly along three orthogonal coordinate axes to infinity. Independent of space, the inexorable flow of universal time kept all motion in step. All events unfolded against the... 

Profiles of averaged factor scores for alertness (arbitrary units) for the outgoing flight and the homegoing flight (UTC Universal Time Coordinates). 

Profiles of three parameters for the EEG alpha band (alpha broadband power, alpha desynchronization index and alpha peak frequency) for the outgoing flight and the homegoing flight. One star denotes an error probability of less than 5%, two stars of less than 1% for the contrasts in the interaction of the factors "time of day" and "flight" (UTC Universal Time Coordinates). 

The exact time of occurrence of the accident was 8 15 a.m. UTC (Universal Time Coordinated), March 20, 1989. All times given in this chapter are expressed as UTC. Intensive evaporation of the liquid pool lasted for up to about eight hours, and the fire was totally extinguished by 5 00 p.m. on March 22 (Lithuanian State Committee for Environmental Protection, 1989). The fire also resulted in releases of nitrogen oxides, fluoride, and chlorine into the air and escape of liquid pollutants into a nearby river. However, because their released amounts have not been quantitatively estimated in the available references, we address only the dispersion of ammonia in the air in this chapter. We also do not address the ammonia releases from the fire. 

For convenience, humans consider their living space to be Euclidean, and even the most advanced cosmologies are still formulated in such terms. In order to operate in Euclidean space, it is necessary to separate the mathematically equivalent variables of Einstein s equation into a universal time variable and the three familiar variables of coordinate space. This operation destroys the 4D field equations and no longer provides any insight into the nature of matter. For this reason, the existence of matter is added to physical theory as an ad hoc postulate—the prescription of classical Newtonian mechanics. 

Since the velocity of light is about 3.0 X 10 m/s, for instance, 3 m error corresponds to 10 ns. So, in this case, the receiver is able to synchronize to the GPS system time with an accuracy of about 10 ns. The GPS system time is derived from the atomic clocks which are implemented in the GPS ground control stations and the GPS satellites. The GPS Navigation Message included in the GPS signals contains parameters that allow the receiver to calculate the correction time from the GPS system time to the UTC (Universal Time Coordinated) with the accuracy of sub-microsecond order (Dana 1997). Therefore, the GPS receiver for time synchronization provides the precise UTC time. 

D.R. McMillin, Purdue University In addition to the charge effects discussed by Professor Sykes, I would like to add that structural effects may help determine electron transfer reactions between biological partners. A case in point is the reaction between cytochrome C551 and azurin where, in order to explain the observed kinetics, reactive and unreactive forms of azurin have been proposed to exist in solution (JL). The two forms differ with respect to the state of protonation of histidine-35 and, it is supposed, with respect to conformation as well. In fact, the lH nmr spectra shown in the Figure provide direct evidence that the nickel(II) derivative of azurin does exist in two different conformations, which interconvert slowly on the nmr time-scale, depending on the state of protonation of the His35 residue (.2) As pointed out by Silvestrini et al., such effects could play a role in coordinating the flow of electrons and protons to the terminal acceptor in vivo. 

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