Observing efficiency

Finally a word about efficiency observing time on large telescopes is a valuable asset, both in terms of cost and considering the ratio of observing time available to the time requested by astronomers. Marco et al. (2001) state that the observing efficiency defined as fhe ratio of science shutter time to available dark time is 10-30% for the ADONIS AO system while the corresponding ratio for other instruments is 50-80%. Some of this difference is due to the fact that most AO exposures are of short duration and the readout time is significant. In addition, AO systems use time to close the loop and optimize performance. Observations may also be necessary to characterize the PSF. 

In DNA RNA hybrids, where intrastrand base stacking is comparable to B-DNA, we observed efficient long range guanine oxidation when using ethidium as an intercalating photooxidant [130]. Conversely, a Rh(III) com-... 

Catenane formation from fluorinated ligand 19 is apparently more effective than that from 12. This difference is most probably because of attractive edge-to-face or CH-jt interaction working in catenane 13, as observed in the crystal structure of platinum-incorporated catenane 14 (Figure 2). In this structure, we can observe efficient edge-to-face aromatic contacts between two phenylene units or a phenylene and a pyridine ring. 

Figure 23-15 Efficiency of energy transfer as a function of distance between a-naphthyl and dansyl groups at the ends of a polyprolyl "rod" (L-prolyl)n. The observed efficiencies of transfer for n = 1 to 12 are shown as points. The solid line corresponds toanr6 distance dependence. From L. Stryer.150...

In fact, the observed efficiency of a liquid junction poly-(acetylene) solar cell is very low (14). 

Fig. 9. Photochemical cells used for the photoassisted electrolysis of H20. In (a) the two electrode compartments are separated by a fine glass frit to prevent diffusion of the 1 N H2SQ4 on the Pt side and 1 M NaOH on the Ti02 side. In (b) applied potentials of > 0.2 V are required to observe efficient photocurrents in the homogeneous electrolyte (from Ref.1891)...

The wall of a fused silica capillary, containing silanol groups, has been identified as a potential site of interaction for solutes in electrophoretic measurements. In particular, adsorption of proteins, peptides and other basic compounds has been more specifically addressed [1-3]. In the ideal situation, the interaction is strictly chromatographic so that the process is reversible with the net result being a loss in the observed efficiency for CE [2,4]. A more serious problem can result when there is irreversible adsorption of the analyte on the capillary wall leading to a lack of repro-... 

In agreement with those observations, efficient production of nonchlorinated REB aglycone (12, arcyriaflavin A) in Strep, albus required the coexpression of four genes ... 

With CdS metalized with platinum or rhodium as the photocatalyst, hydrogenation was about four times more efficient than hydrogen evolution, with the observed efficiency depending on the solution-phase pH and the identity and loading of the metal catalyst. 

Lewis and coworkers have also observed efficient intramolecular photoaddition for several (A,A-dimethylaminoalkyl)styrenes, leading to the formation of nitrogen heterocycles or aminocycloalkanes (Scheme 53) [287]. 

The numerical results for t)opdp = l-z0PDP are compared with r CAN and the observed efficiency, lobs which are in good agreement with the reported values. Now, assuming that z obtained from Equation (34) can be expressed as a power series in the parameter A, the expression for the efficiency at maximum power output regimen is as follows ... 

Methodological approach adsorption of As(V) on the graphite surface observed, efficient separation of four species [except As(V)] within 10 min, DL ranging from 10 to 70 ng AsL natural, arsenic-containing freshwater analyzed... 

The electro-osmotic transport of water during EOD leads to very high energy efficiencies for example, the observed efficiencies of 5.6 ml/mAh (1.55 ml/C) are equivalent to 8300 moles of water per Faraday of electricity, so that EOD is extremely cost effective. 

The physical properties of polymers can be affected by structural irregularities present in the polymers. These structural irregularities include end groups and side branches which affect melting points, thermal stability and so on. The existence of such irregularities can be observed efficiently by solution-state NMR, because the line widths of solution peaks are typically 10-100 times narrower than those of solid-state NMR. However, by solid-state NMR, we can seek how the side groups and end groups are partitioned between the crystalline and amorphous phases, which directly relate to the physical properties of the polymers. 

Studies on proton transfer to and from carbon in model reactions have shown that the activation barrier to most enzyme-catalyzed reactions is composed mainly of the thermodynamic barrier to proton transfer (Fig. 1.1), so that in most cases this barrier for proton transfer at the enzyme active site will need to be reduced in order to observe efficient catalysis. A smaller part of the activation barrier to deprotonation of a-carbonyl carbon is due to the intrinsic difficulty of this reaction to form a resonance stabilized enolate. There is evidence that part of the intrinsic barrier to proton transfer at a-carbonyl carbon reflects the intrinsic instability of negative charge at the transition state of mixed sp -sp -hybridization at carbon [79]. Small buffer and metal ion catalysts do not cause a large reduction in this intrinsic reaction barrier. 

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