Annular arrays

With injection mixers (Figures 10.52b,c), in which the one fluid is introduced into the flowing stream of the other through a concentric pipe or an annular array of jets, mixing will take place by entrainment and turbulent diffusion. Such devices should be used where one flow is much lower than the other, and will give a satisfactory blend in about 80 pipe diameters. The inclusion of baffles or other flow restrictions will reduce the mixing length required. 

The piezoceramics can be fabricated in a number of ways to perform B-mode imaging. In its simplest form, the B-mode transducer is a circular single-element transducer with a fixed geometric focus. To a large degree this type of a transducer has been replaced today by more sophisticated multielement transducers however, there are still commercial systems where single-element transducers are used. The next more complicated designs are annular arrays, which are also circular but. 

Mechanical Steering. The simplest method of beam steering is to use a mechanism to reorient a transducer (usually a circular aperture) to a predetermined set of orientations so as to capture the required two-dimensional data set. This approach was dominant at first however, in the last 15 years, electronically steered systems have become, by far, the most popular. Mechanical systems usually use either a single-element transducer or an annular array transducer (Fig. 25.8). Tlie former will have a fixed focus while the latter does allow the focal point to be moved electronically. This will be discussed more fiilly later. 

Tahnan, J. R. and Garverick, S. L. (2001) Integrated-Circuit Implementation of a Matched-Cell Dynamic Focusing Architecture for a 5-Channel, 50-Mhz Planar Annular Array, Proceedings of the 2001 IEEE Ultrasonics Symposium, 2, 1109-1112. 

Arditi, M., Foster, F. S. and Hunt, J. W. (1981) Transient fields of concave annular arrays. 

The use of annular array transducers provides high-resolution images over large areas. In fact, concentric annular ring elements driven by a phase-controlled pulse can shift the focal point along the transducer axis. 

CAREM uses once-through straight tube steam generators. Twelve steam generators are arranged in an annular array inside the pressure vessel above the core. The primary side coolant flows through the inside of the tubes, and the secondary side water flows across the outside of the tubes. A shell and two tube plates form the barrier between primary and secondary circuits. 

Heterocyclic betaines of azinium (azolium) azolate with different inter-annular spacers 1 constitute a vast array of highly dipolar chemical entities with low molecular weight. In Scheme 2, it has been stressed that sesquiful-valene 3 can be broken down into various types of betaines and compounds with a betaine character. From the studies reviewed, it is apparent that Scheme 1 is transformed to Scheme 11. The present level of knowledge... 

Figure 5 Approximation of a central subchannel in (a) a square array by (b) an annular channel.

Figure 3.1 ESI Chip consisting of a 20 by 20 array of microfabricated nozzles etched from a silicon wafer. The inset shows scanning electron micrographs showing a nozzle with annular space and a nozzle prior to dielectric coating of the wafer. Nozzle dimensions in the inset are 10 pm i.d., 22 pm o.d. by 55 pm height.

There seems little doubt that the dissolved complex is an inclusion compound in which iodine resides within the annular cavity of a more or less regular helical amylose chain. This picture emerged early from the work of Rundle and coworkers on the crystalline (10) and dissolved (11) complex and has not been seriously challenged by any more recent studies. Despite the acknowledged helical character of the dissolved complex, it is very clear from hydrodynamic evidence that the complexed polymer does not adopt a rigid, rod-like conformation indeed, the hydrodynamic volune of the polymer decreases upon complexation with iodine (2. 3, ) The spectroscopic properties of the dissolved complex imply that the bound iodine is arrayed in linear sequences, but neither the... 

Branagan, S.P., Contento, N.M., Bohn, P.W. Enhanced mass transport of electroactive species to annular nanoband electrodes embedded in nanocaphlary array membranes. J. Am. Chem. Soc. 134, 8617-8624, 2012. 

The initial SNL analysis used the core model depicted in Fig. 3.1. ° A 2.54-cm-diam fuel compact was surrounded by six 0.8-cm-diam coolant channels in a hexagonal array with a 3. 41-cm pitch. The fuel and coolant channels were contained in an annular core region (i.e., the individual hexagonal fuel assemblies were not modeled explicitly). This yielded a 10% coolant voliune fraction and a 50% fuel-compact volume fraction. The computed void coefficients for total core voiding are given in Table 3.1 for several candidate salts. For salts containing Li, it was assumed that the lithiiun contained no °Li isotope. 

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