Spray-pulse techniques

Spray-pulse techniques improve the vaporisation of liquid hydrocarbons when fed to the reformer reactor [93]. 

ZnO thin films can be prepared by a variety of techniques such as magnetron sputtering, chemical vapor deposition, pulsed-laser deposition, molecular beam epitaxy, spray-pyrolysis, and (electro-)chemical deposition [24,74]. In this book, sputtering (Chap. 5), chemical vapor deposition (Chap. 6), and pulsed-laser deposition (Chap. 7) are described in detail, since these methods lead to the best ZnO films concerning high conductivity and transparency. The first two methods allow also large area depositions making them the industrially most advanced deposition techniques for ZnO. ZnO films easily crystallize, which is different for instance compared with ITO films that can... 

A visualization study of fuel atomization using a pulsed laser holography/photography technique indicates that basic spray formation processes are the same for both a coal-derived synthetic fuel (SRC-II) and comparable petroleum fuels (No. 2 and No. 6 grade). Measurements were made on both pressure swirl and air assisted atomizers in a cold spray facility having well controlled fuel temperature. Quality of the sprays formed with SRC-II was between that of the No. 2 and No. 6 fuel sprays and was consistent with measured fuel viscosity. Sauter mean droplet diameter (SMD) was found to correlate with fuel viscosity, atomization pressure, and fuel flow rate. For all three fuels, a smaller SMD could be obtained with the air assisted than with the pressure swirl atomizer. 

Pulsed laser holography and photography provide a powerful technique for the instantaneous visualization of spray processes. 

Particle size measurements were made using an UV-laser, shadow photographic technique. The particle sizing system displayed real-time droplet images onto a television monitor. The images (shadows) were obtained when a pulsed (30 times per second) UV-laser beam was directed through a spray scene onto a synchronized UV-sensitive vidicon camera/recorder. The narrow depth of field used by this system can record shadows from 300 in-focus droplets per second with a resolution down to approximately 0.3 /un in diameter. 

Fig, 10.24. Simplified schematics illustrating some deposition techniques (a) thermal evaporation (b) stamping (c) liquid-solid interface (d) electro-chemistry set-up (e) Langmuir-Blodgett technique (f) electro-spray deposition (g) pulse injection method (h) solution casting (i) spin-coating. 

Gas Introduction and Matrix Formation. For introduction of gases for condensation and formation of matrices in the cryostat system, we employed two types of deposition technique SSO (Slow Spray-On) and PMI (Pulsed Matrix Isolation). In the SSO run, matrix gas (pure nitrogen, or argon) and sample were introduced slowly and separately into the setup via fine needle valves with micrometers. In the PMI (Pulsed Matrix Isolation) run, a mixture of matrix gas and sample(s) was introduced via electromagnetic valves controlled by a micro-computer. In PMI runs, not only was the deposition rate easily controlled over a wide range with good reproducibility, but a stratified matrix could also be prepared if two kinds of gas samples are introduced alternately and repeatedly. 

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