Practical Details

The coincidence rate (the rate of complete start-stop events) of the Hanbury-Brown-Twiss experiment is normally very low. At the light intensity obtained from typical samples, it is relatively unlikely that two photons appear within a time interval of a few nanoseconds. For classic light the coincidence rate can be estimated as follows  

The detection rate in the start detector is r the detection rate in the stop detector The probability that the stop detector detects a photon in the coincidence time interval, At, after a start photon is = r At. Therefore the coincidence rate is 

Both rates, and are proportional to the efficiency of the optical system and the quantum efficiency of the detectors. Consequently the eoineidence rate, r.  

Recently new single-photon avalanche photodiodes have been introduced, see Sect. 6.4.10 page 258. Compared with the SPCM-AQR the new devices have a considerably improved timing behaviour but lower quantum efficiency in the NIR. However, the efficiency below 600 nm is comparable or even better than for the SPCM-AQR. It is likely though not proved that these detectors are superior to the SPCM-AQR for correlation measurements in the visible spectral range. 

The collection efficiency of the optical system increases with the square of the effective numerical aperture of the microscope objective lens. A good lens is therefore essential in order to obtain a high coincidence rate. If the sample is transparent the light can be collected from both sides, either by the condenser lens of the microscope or by a second microscope lens. Theoretically, the collection efficiency can be doubled and the coincidence rate increased by a factor of four. Moreover, in a microscope with two aligned microscope lenses exciting and detecting from both sides of the sample, the focal volume can be considerably decreased [64, 448] 

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Outline how you would determine the concentration of permanganate ions in the product (practical details are not required). 

Filtration. Before discussing the practical details of the purification of solid substances by recrystallisation, it is convenient to describe here the general methods of filtration. The two principal occasions in organic chemistry when filtration is necessary are ... 

Identification of Aromatic Hydrocarbons. Picric acid combines with many aromatic hydrocarbons, giving addition products of definite m.p. Thus with naphthalene it gives yellow naphthalene picrate, C oHg,(N08)jCeHiOH, m.p. 152°, and with anthracene it gives red anthracene picrate, C 4Hio,(NOj)jCeHjOH, m.p. 138 . For practical details, see p. 394. 

Representative Method The best way to appreciate the importance of the theoretical and practical details discussed in the previous section is to carefully examine the procedure for a typical precipitation gravimetric method. Although each method has its own unique considerations, the determination of Mg + in water and waste-water by precipitating MgNH4P04 6H2O and isolating Mg2P20y provides an instructive example of a typical procedure. 

The previous discussion demonstrates that measurement of precise isotope ratios requires a substantial amount of operator experience, particularly with samples that have not been examined previously. A choice of filament metal must be made, the preparation of the sample on the filament surface is important (particularly when activators are used), and the rate of evaporation (and therefore temperature control) may be crucial. Despite these challenges, this method of surface ionization is a useful technique for measuring precise isotope ratios for multiple isotopes. Other chapters in this book discuss practical details and applications. 

Practical details of the Cronak process are given in Specification DEF-130, and a comprehensive account of the process as applied to zinc plate has been published by Clarke and Andrew. Fig. 15.5 shows the loss of zinc and the... 

In this section we concentrate on the types of reaction, their kinetics, stereochemistry, and mechanism, and deal with the above groups in turn Section IV deals with the practical details of applying these and other reactions to the synthesis of organocobalt(III) complexes. 

In school demonstrations of the oxidation of ammonia to nitric acid over platinum catalysts, substitution of oxygen for air causes fairly vigorous explosions to occur [1], Practical details are given [2],... 

A detailed review of i.t. dosing has recently been published [46], which provides practical details of the technique. 

D. F Gray, The Observation and Analysis of Stellar Photospheres, Cambridge University Press 2005, gives many useful practical details in this field, including a description of Fourier analysis of line profiles. 

If the optically active medium is not transparent at the wavelength of the incident radiation, the transmitted intensity may be further reduced by an absorptive contribution to the index of refraction. Because of preferential absorption of either the left or the right circularly polarized component, the emerging beam would no longer be the sum of equal amplitudes and trace out an ellipse with ellipticity tp = (kt — kr). Practical details of the measurement and chemical applications of optical activity are discussed by Charney[34],... 

In keeping with the earlier format we aim to provide the readership with sufficient practical details for the preparation and successful use of the relevant catalyst. Coupled with these specific examples, a selection of the products that may be obtained by a particular technology will be reviewed. 

Give exact practical details of the proposed procedure (use separate sheets if necessary). You should include any practical tips/hints gained through personal experience. 

A more detciiled account of the parallelization may be of interest to researchers seeking to parallelize electronic structure codes. We consider therefore in this section those aspects of the parallelization that are not directly related to the direct Cl algorithm discussed in Section 2. We first state our overall implementationaJ objectives, followed by some more practical details, including also a description of the PVM [17,18] message passing facility used. 

The purpose of this chapter is not to address the continuing controversy about the electronic nature of the electron-doped superconductors, but rather to review the crystal chemistry of the T -Nd2Cu04 system and give practical details on how to prepare crystallographically pure electron-doped superconductors in ceramic or single-crystal form with high Meissner fractions. 

This chapter initially provides an overview of the considerations associated with the synthesis of inorganic polymers and the reasons why inorganic rings are so important as polymer precursors. The methods commonly used to characterise polymers are then discussed. As in Chapter 3, which describes the techniques used for the characterisation of inorganic rings, this section focuses on utility rather than on theoretical and practical details of the different methods. The reader is referred to a variety of texts for further details about these polymer structural characterisation techniques. ... 

In keeping with the earlier format we aim to provide the readership with sufficient practical details for the preparation and successful use of the relevant catalyst. Coupled with these specific examples, a selection of the products that may be obtained by a particular technology will be reviewed. In the different volumes of this new series we will feature catalysts for oxidation and reduction reactions, hydrolysis protocols and catalytic systems for carbon-carbon bond formation inter alia. Many of the catalysts featured will be chiral, given the present day interest in the preparation of single-enantiomer fine chemicals. When appropriate, a catalyst type that is capable of a wide range of transformations will be featured. In these volumes the amount of practical data that is described will be proportionately less, and attention will be focused on the past uses of the system and its future potential. 

R.Kaiser, Gas Chromatography, vol.3, Butterworths, London, 1963 (practical details of liquid phases, adsorbents, etc., with references). 

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