Fluidics

Fig. 14. Cross sections of oscillatory flow meters (a) fluidic, where (—fc.) represents the main flow and (-...

Commercial appHcations include substrates, fluidic devices, fine mesh screens, and magnetic head pads. 

Fig. 36. Examples of specially designed mixers (a) draft tube circulator, (b) airlift with draft tube, (c) Fluidics vortex mixer, and (d) mixer emulsifier.

Microfabrication techniques used for the production of MEMS (micro electro-mechanical systems) have been successfully used to produce highly efficient micro fluidic systems. 

Electroosmotic flow (EOE) is thus the mechanism by which liquids are moved from one end of the sepai ation capillai y to the other, obviating the need for mechanical pumps and valves. This makes this technique very amenable to miniaturization, as it is fai simpler to make an electrical contact to a chip via a wire immersed in a reservoir than to make a robust connection to a pump. More important, however, is that all the basic fluidic manipulations that a chemist requires for microchip electrophoresis, or any other liquid handling for that matter, have been adapted to electrokinetic microfluidic chips. 

DEVELOPMENT OF A CHEMILUMINESCENCE DETECTION OF HERBICIDES RELATIVE TO THE MEDIATED INHIBITION OF THYLAKOIDS IN A ji-FLUIDIC SYSTEM... 

A method of detecting herbicides is proposed the photosynthetic herbicides act by binding to Photosystem II (PS II), a multiunit chlorophyll-protein complex which plays a vital role in photosynthesis. The inhibition of PS II causes a reduced photoinduced production of hydrogen peroxide, which can be measured by a chemiluminescence reaction with luminol and the enzyme horseradish peroxidase (HRP). The sensing device proposed combines the production and detection of hydrogen peroxide in a single flow assay by combining all the individual steps in a compact, portable device that utilises micro-fluidic components. 

McRee, D. I., and H. L. Moses. 1967. The effect of aspect ratio and offset on nozzle flow and jet reattachment. In Advances in Fluidics The 1967 Fluidics Symposium. ASME. 

A pipe that releases gas to disperse into the atmosphere is called a vent. If the gas is burned at the tip, it is called a flare. In its simplest form, a vent or flare tip is a pipe. Sometimes the pipe diameter is reduced for the last 5 ft or so to increase exit velocity for better mixing with the air. The operating pressure of the vent scrubber can be adjusted by reducing the tip diameter to increase pressure drop across the tip. Fluidic seal., also give increased pressure drop and can be used to reduce the infusion... 

Figure 7-7. Fluidic check valve. Illusiration courtesy of AEA Techuolot y.)...

Figure 7-71. Flare stack arrangement for smokeless burning and backflash protection with Fluidic Seal molecular seal. Steam can be injected into the flare to introduce air to the fuel by use of jets inside the stream and around the periphery. By permission, Straitz, J. F. Ill, Make the Flare Protect the Environment," Hydrocarbon Processing, Oct. 1977, p. 131.

Fluidic Pulser System. A new type of pulser is being developed at Louisiana State University. It is based on a patent by A. B. Holmes [107]. The throttling of the mud is obtained by creating a turbulent flow in a chamber as shown in Figure 4-249. 

Figure 4-249. Fluidic mud pulser principlet. (Courtesy Louisiana State University [107]. ...

Example 11 Mud Pulse Telemetry—Fluidic Puiser Calculations... 

We have built a fluidic puiser system that can generate approximately 100 psi peak to peak with 500 gal/min mud flowrate. It is to be used down to 15,000 ft. The surface detector needs a 5-psi peak to peak sine wave for proper phase detection. The following oil-base mud is used ... 

The mud flow rate is 500 gal/min and the fluidic pulser has 4 x 24/32 in. diameter nozzles in parallel. Compute the pressure loss in the fluidic pulser in the minimum loss mode (C = 1). 

Holmes, A. B., Fluidic mud pulser concepts in MWD, Proceedings MWD Symposium, Louisiana State University, Baton Rouge, February 26-27, 1990. 

Bayraktar T, Pidugu SB (2006) Characterization of liquid flows in micro-fluidic systems. Int J Heat Mass Transfer 49 815-824... 

Wen, S. M., Theories of Micro-fluidic Boundary Layers and Its Application, Beijing, Metallurgical Industry Press, 2002. 

The last category is the pressure-driven gas flows, which are typical in micro gas fluidic and micro heat transfer systems. Because the channel diameter or width in micro gas fluidic systems is in the scale of sub-micrometer or less, ultra-thin gas lubrication theory plays an important role in... 

External numbering-up benefits from true repetition of the fluidic path, and hence preserves all the transport properties and hydrodynamics, determined in advance for a single-device operation. This is commonly believed to result in a... 

Matching Fluidics to Physico-chemical Requirements of a Reaction... 

Wegeng et al. mentioned fouling as a major problem, decreasing micro-fluidic system reliability [1]. Active control over fouling was demanded in their review, but no strategies to overcome it were given. 

For catalyst testing, conventional small tubular reactors are commonly employed today [2]. However, although the reactors are small, this is not the case for their environment. Large panels of complex fluidic handling manifolds, containment vessels, and extended analytical equipment encompass the tube reactors. Detection is often the bottleneck, since it is still performed in a serial fashion. To overcome this situation, there is the vision, ultimately, to develop PC-card-sized chip systems with integrated microfluidic, sensor, control, and reaction components [2]. The advantages are less space, reduced waste, and fewer utilities. 

The integration of sensing and other functions in a micro-flow system requires either monolithic, on-chip or hybrid, multi-scale approaches. Concerning the latter, Hessel and Lowe discuss the lack of compatibility of today s fluidic interfaces and report on a German project team developing a standard for micro-reactor interconnection [9, 10]. 

Figure 1.27 Standardized fluidic backbone for connecting micro-reactor components from different suppliers, yielding a small, compact micro-plant with multiple functions.

This backbone not only has a fluidic path, but also contains an electric bus system. 

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