Droplet spray

Berriman J and Unwin N 1994 Analysis of transient structures by cryo-electron microscopy combined with rapid mixing of spray droplets Ultramicroscopy 56 241-52... 

Fig. 20. Spray droplet target efficiency in a centrifugal spray tower with a centrifugal field of 100 g (140,281).

FIG. 14-126 Predicted spray-tower cut diameter as a function of sprayed length and spray droplet size for (a) vertical-countercurrent towers and (b) horizontal-cross-flow towers per Calvert [ J. Air Polliit. Control Assoc., 24, 929 (1974)]. Curve 1 is for 200-pm spray droplets, curve 2 for 500-pm spray, and curve 3 for 1000-pm spray. QHQc is the volumetric hqiiid-to-gas ratio, L liqiiid/nri gas, andt/cis the siiperBcial gas velocity in the tower. To convert liters per ciihic meter to cubic feet per cubic foot, multiply by 10 . ... 

Mists and Sprays - There are numerous industrial chemical operations which involve liquid-in-gas dispersions. These operations generate mists and sprays that consist of particles in diameter ranges of 0.1 to 5,000 fim. Engineers most commonly encounter spray droplets which are particles often formed unintentionally in chemical plant operations. For example, vapors or fumes may condense onto piping, ducts, or stack walls. Under such conditions liquid films form. 

Most of the methyl parathion deposited onto soils is through deposition of spray droplets that fall to the ground following spraying. An estimated 5.95 million pounds of methyl parathion were used on a variety of crops in the United States in 1992 (Gianessi and Anderson 1995). 

One problem that has arisen with the use of herbicides in agriculture is spray or vapor drift. When fine spray droplets are released, especially if applied aerially, they may be deposited beyond the target area due to air movements to cause damage there. In the first place, this is a question of application technique. Herbicides, like other pesticides, should not be applied as sprays under windy conditions. In most... 

The APCI interface uses pneumatic nebulization in an atmospheric pressure region to form fine spray droplets. Typically, these systems use a heated nebulizer (300-650 °C)... 

Spray nozzle type plays an important role in the success of agrochemical application. For broadcast applications to soil, flat fan nozzles should be used. Newer spray tips such as the DG TeeJet, XR TeeJet, Turbo TeeJet and similar nozzles supplied by Lechler and Hardy have provided acceptable results in a number of studies. For a given nozzle type, the lower the application pressure, the larger is the spray droplet size and the less potential for spray drift. Similarly, the closer the boom is positioned to the soil surface, the less is the potential for spray drift." Most applications are made with spray tips having 80° or 110° spray angles and boom heights of about 50 cm above the soil surface. 

Figure 21.6 Time-lapse observation of synaptic acid crystal formation. The spray-droplet method forms very fine crystals inside and outside of the matrix drop (a-d), so that finer and more homogeneous crystals are generated (d) than those obtained by the droplet method (e-h). Observation with a scanning electron microscope of matrix crystals with the spray-droplet (i) and droplet methods (j). Reprinted with permission from Sugiura et al.7... 

Figure 21.7 Comparison of mass spectra obtained from rat brain. Optical observation of microspotted tissue sections employing spray-droplet (a), droplet (b), and spraycoating (c) methods. Scale bar, 1.0 mm. White squares (a-c) represent the cortex (A, d) and the medulla (B, e) of the cerebellum region, respectively. Accumulated mass spectra collected from each region are shown (d, e). In each spectrum, asterisks represent major unique signals for spectra using the spray-droplet method. The number of detected signals in the mass range of 2000 < m/z < 30,000 from each region is shown (f). Reprinted with permission from Sugiura et al.7...

Figure 21.8 Comparison of IMS indicating protein distribution in the rat brain section corresponding to Figure 21.7 (a-c) the spray-droplet (a), droplet (b), and spray-coating (c) methods are used. Reprinted with permission from Sugiura et al.7 See color insert.

Atmospheric pressure chemical ionization (APCI) was introduced in 1973 by Horning et al. [38, 42, 43] and coupled to GC. This is also the introduction of atmospheric pressure ionization (API) in general. The next year corona discharge was introduced for ion generation as well as successful coupling to LC [44, 45]. In APCI of a liquid, a pneumatic nebulizer induces the flow of liquid to form a spray at atmospheric pressure. The spray droplets pass a corona discharge electrode situated close to the orifice, which... 

Spray droplet size distribution, 23 185-186 Spray drop size, 23 174-175 Spray-dry encapsulation processes, 16 447- 457... 

Aerosol production and transport over the oceans are of interest in studies concerning cloud physics, air pollution, atmospheric optics, and air-sea interactions. However, the contribution of sea spray droplets to the transfer of moisture and latent heat from the sea to the atmosphere is not well known. In an effort to investigate these phenomena, Edson et al.[12l used an interactive Eulerian-Lagrangian approach to simulate the generation, turbulent transport and evaporation of droplets. The k-e turbulence closure model was incorporated in the Eulerian-Lagrangian model to accurately simulate... 

Droplet collision is a phenomenon inherent in the dense region of a spray. Droplet collisions may lead to local agglomeration that affects the droplet size distribution. There have been considerable efforts in modeling droplet-droplet collisions and coalescence,12291 but the models are still not generally applicable. 1576] Moreover, the calculations in the dense region of a metal spray is much more complicated than in a diesel spray because the physical phenomena and mechanisms in the dense region are not well understood. 

Collection Techniques. The simplest mechanical method for normal liquid droplets is the slide collection slide sampling) or impression method. This method was extensively used three decades ago, and has been rarely employed since then. In this method, when the slide is exposed to a spray, droplets impinging on it make impressions. The impressions are then observed and measured usually using a Quantimet image analyzer, although a microscope fitted with a traversing scale may be used for the measurement. The measured data are subsequently converted to actual droplet sizes based on a correction factor proposed by May.[659]... 

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