Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Long Rules

There has been much confusion over the structure of these compounds but their diamagnetism has long ruled out a monomeric formulation, H2PO3. In fact, as shown in Table 12.7, isomeric forms are known (a) hypophosphoric acid and hypophosphates in which both P atoms are identical and there is a direct P-P bond (h) isohypophosphoric acid and isohypophos-phates in which 1 P has a direct P-H bond... [Pg.515]

Certainly, and you will do as he advises. But until you are crowned he is Protector of the realm, and he will be much taken up with affairs of state. Besides, from his long ruling of the north, he knows less well what is toward with the London merchants, for example, and the contracts to supply the household. ... [Pg.290]

An ocular micrometer is a disk on which is etched a scale in units from 0 to 50 or 100. To determine the micrometer value of each unit in a particular eyepiece and at a specific magnification, the unit must be calibrated with a stage micrometer. A stage micrometer has a scale 2 mm long ruled in fine intervals of 0.01 mm (10 finl). [Pg.9]

Break lines indicate that only a portion of an object is drawn. Such lines are commonly depicted as shown in Figure 6.5. Alternately, long ruled thin dashes joined by zigzags may be used for break lines. [Pg.155]

The increased exposure to the reservo/r results from the long horizontal sections which can be attained (between 500m and 1000m horizontal section is now common). Because the productivity index is a function of the length of reservoir drained by a well, horizontal wells can give higher productivities in laterally extensive reservoirs. As an initial estimate of the potential benefit of horizontal wells, one can use a rough rule of thumb, the... [Pg.218]

The immediate site of the adsorbent-adsorbate interaction is presumably that between adjacent atoms of the respective species. This is certainly true in chemisorption, where actual chemical bond formation is the rule, and is largely true in the case of physical adsorption, with the possible exception of multilayer formation, which can be viewed as a consequence of weak, long-range force helds. Another possible exception would be the case of molecules where some electron delocalization is present, as with aromatic ring systems. [Pg.591]

Spectroscopists observed that molecules dissolved in rigid matrices gave both short-lived and long-lived emissions which were called fluorescence and phosphorescence, respectively. In 1944, Lewis and Kasha [25] proposed that molecular phosphorescence came from a triplet state and was long-lived because of the well known spin selection rule AS = 0, i.e. interactions with a light wave or with the surroundings do not readily change the spin of the electrons. [Pg.1143]

Many experimental techniques now provide details of dynamical events on short timescales. Time-dependent theory, such as END, offer the capabilities to obtain information about the details of the transition from initial-to-final states in reactive processes. The assumptions of time-dependent perturbation theory coupled with Fermi s Golden Rule, namely, that there are well-defined (unperturbed) initial and final states and that these are occupied for times, which are long compared to the transition time, no longer necessarily apply. Therefore, truly dynamical methods become very appealing and the results from such theoretical methods can be shown as movies or time lapse photography. [Pg.236]

One limitation of this method that should immediately come to mind is the restriction to relatively low molecular weight polymers. This is a corollary of the fact that chain ends are inconsequential for very long chains. Hence, the sensitivity of the method decreases as the molecular weight of the polymer increases. As a general rule, molecular weights in the neighborhood of 25,000 represent the upper limit for applicability of this method. [Pg.30]

The first excited singlet state, 2 Sq, is also metastable in the sense that a transition to the ground state is forbidden by the Af selection rule but, because the transition is not spin forbidden, this state is not so long-lived as the 2 Si metastable state. [Pg.221]

As a general rule, marketing research studies involving comprehensive coverage of competitive firms requkes personal contacts. Telephone inquiries usually are futile unless the respondent is a friend of long-standing, the mail surveys are generally unsuitable. [Pg.536]

As a rule, LLDPE resins do not contain long-chain branches. However, some copolymers produced with metallocene catalysts in solution processes can contain about 0.002 long-chain branches per 100 ethylene units (1). These branches are formed in auto-copolymerisation reactions of ethylene with polymer molecules containing vinyl double bonds on their ends (2). [Pg.395]

Process plant design has come a long way from the early 1930s when process designers used the rule-of-thumb that a process faciUty could not be scaled-up more than 10-fold (2). American Oil s Ultracracking unit (Texas City, Texas) for example, was designed from data from a small pilot plant with a scale-up factor of 80,000 (3). [Pg.40]

The direction of the long-wavelength maximum shift caused by the heterosubstitution or the introduction of substituents is deterrnined by the Forster-Dewar-Knott rule (40—42). Spatial hindrances within the symmetrical PMDs cause bathochromic effects (39,43), whereas the introduction of an acetylenic bond is accompanied by the maximum shift to the short-wavelength spectral region (44). [Pg.494]


See other pages where Long Rules is mentioned: [Pg.17]    [Pg.148]    [Pg.6]    [Pg.114]    [Pg.127]    [Pg.130]    [Pg.17]    [Pg.148]    [Pg.6]    [Pg.114]    [Pg.127]    [Pg.130]    [Pg.414]    [Pg.686]    [Pg.1635]    [Pg.252]    [Pg.228]    [Pg.398]    [Pg.506]    [Pg.6]    [Pg.33]    [Pg.79]    [Pg.228]    [Pg.115]    [Pg.70]    [Pg.77]    [Pg.242]    [Pg.467]    [Pg.1286]    [Pg.153]    [Pg.721]    [Pg.250]    [Pg.484]    [Pg.199]    [Pg.533]    [Pg.118]    [Pg.230]    [Pg.491]   
See also in sourсe #XX -- [ Pg.6 , Pg.114 , Pg.124 ]




SEARCH



© 2024 chempedia.info