Sodium emission from

The reactions, which cause the thennal decon osition of black liquor, are varied. Several mechamstns can be found in literature, most of then are centered in sodium emissions from black liquor during their pyrolysis and gasification [6]. Some of them are the following ... 

When the mercury present in the atmosphere is primarily in the form of an organic mercury compound, it may be preferable to utilise an aqueous scmbber. This method is particularly useful for control of emissions from reactors and from dryers. For efficient and economical operation, an aqueous solution of caustic soda, sodium hypochlorite, or sodium sulfide is reckculated through the scmbber until the solution is saturated with the mercury compound. 

The detection and quantitation of y-emission from is accompHshed by well counting. A thaUium-activated sodium iodide crystal, having a well... 

Optimized modern dry scrubbing systems for incinerator gas cleaning are much more effective (and expensive) than their counterparts used so far for utility boiler flue gas cleaning. Brinckman and Maresca [ASME Med. Waste Symp. (1992)] describe the use of dry hydrated lime or sodium bicarbonate injection followed by membrane filtration as preferred treatment technology for control of acid gas and particulate matter emissions from modular medical waste incinerators, which have especially high dioxin emissions. 

For a typical sodium atom, the initial velocity in the atomic beam is about 1000 m s1 and the velocity change per photon absorbed is 3 crn-s. This means that the sodium atom must absorb and spontaneously emit over 3 x 104 photons to be stopped. It can be shown that the maximum rate of velocity change for an atom of mass m with a photon of frequency u is equal to hu/lmcr where h and c are Planck s constant and the speed of light, and r is the lifetime for spontaneous emission from the excited state. For sodium, this corresponds to a deceleration of about 106 m s"2. This should be sufficient to stop the motion of 1000 m-s 1 sodium atoms in a time of approximately 1 ms over a distance of 0.5 m, a condition that can be realized in the laboratory. 

The colors of fireworks displays are produced by emission from atomic ions as described in Chapter 7. The explosions of fireworks promote electrons to excited states. The energy level scheme of every element is different, so fireworks manufacturers can change colors by incorporating different elements. Sodium ions emit... 

Eor example, street lamps use the emissions from excited sodium atoms, the dazzling colors of a fireworks display come from photons emitted by metal ions in excited states, and the red light in highway flares often comes from excited Sr ions. 

Choi and Funayama [19] also measured sodium atom emission from sodium dodecylsulfate (SDS) solutions in the concentration range of 0.1-100 mM at frequencies of 108 kHz and 1.0 MHz. The sodium line intensity observed at 1 MHz was nearly constant in the concentration range from 3 to 100 mM and was considerably higher than that at 108 kHz. This frequency dependence of the intensity is opposite that for NaCl aqueous solution. The dynamical behavior of the absorption and desorption of surfactant molecules onto the bubble surface may affect the reduction and excitation processes of sodium atom emission. This point should be clarified in the future. 

Abe and Choi [41] succeeded in the spatiotemporal separation of sodium atom emission from continuum emission in argon-saturated NaCl aqueous solution... 

Streetlights show d-line emission from excited sodium atoms at wavelengths of 589.76 nm and 589.16 nm. 

The yellow flame colour is due to atomic emission from sodium where the spectrum is dominated by a broad emission centred on 590 nm (the resonance transition is that from the ground state to the lowest energy excited state in absorption and the reverse will apply in emission). 

Richardson and Young (Proc. Roy. Soc. A, evil. 377,1925) in an examination of the thermionic and photoelectric emission from surfaces of sodium and potassium have observed more than one threshold value for the work functions and suggest that in these cases also there are small patches of the surface associated with a low value of the work function. 

Yellow flame color is achieved by atomic emission from sodium. The emission intensity at 589 nanometers increases as the reaction temperature is raised there is no molecular emitting species here to decompose. Ionization of sodium atoms to sodium ions will occur at very high temperatures, however, so even here there is an upper limit of temperature that must be avoided for maximum color quality. The emission spectrum of a yellow flare is shown in Figure 7.2. 

In Reference [38], it is further shown that suppression of the spontaneous emission can be equally well achieved in a molecular system. The difficulty with molecular systems lies in the fact that there is usually a multitude of final states to which the system can emit. In this example, suppressing the emission from a particular vibrational state a) belonging to the 1 S (A) electronic manifold of the Sodium dimer is considered, when aided by a particular vibrational state b) belonging to the 2 electronic manifold. The relevant potentials are displayed in Figure 9.12. 

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