Processor synthesis

Optimization based on neural network solvers has been investigated, too. This technique has been applied with good results to the assignment problem as it occurs during lowly multiplexed processor synthesis [34]. 

In this chapter, we will present the processor synthesis part of THEDA. The general design consideration is described in Section 2. The target architecture is described in Section 3. Scheduling is described in Section 4. Constructive and iterative refined approaches to the data path binding problem are described in Section 5. Finally, we conclude with a summary. 

We have described an approach for processor synthesis. We divide the problem into three interdependent subtasks, namely, operation scheduling, data path binding and controller synthesis. The first subtask includes both time-constrained and resource-... 

Methanol has been considered as a fuel for fuel-cell vehicles with on-board fuel processors for some time. Dimethyl ether (DME) has been suggested as a fuel alternative for diesel engines in Japan and Sweden. The synthesis of DME is based on methanol synthesis followed by DME formation ... 

One particularly efficient alternative is to develop SARs not with experimental molecular properties, but with predicted ones. Thus, if the drug company database is augmented with predicted values, and a SAR on predicted values proves useful based on data for compounds already assayed, potential new compounds can be examined in a purely computational fashion to evaluate whether they should be priority targets for synthesis. In 1998, Beck et al. (1998) optimized the geometries of a database of 53000 compounds with AMI in 14 hours on a 128-processor Origin 2000 computer. Such speed is presently possible only for semiempirical levels of theory. Once the geometries and wave functions are in hand, it is straightforward (and typically much faster) to compute a very wide variety of molecular properties in order to survey possible SARs. Note that for the SAR to be useful, the absolute values of the computed properties do not necessarily need to be accurate - only their variation relative to their activity is important. 

The two broad classes of photochemical reactors are the batch processors and the continuous processors. The batch processor is simple in design, but costly in operation, because it requires the loading of the reactant, the unloading of the product and the cleaning of the reactor vessel all operations which involve human intervention. Batch processing is used as a rule in laboratory synthesis, but industrial applications prefer continuous systems for reasons of efficiency. Still, it must be accepted that batch processing will be used for many small-scale industrial syntheses. 

In spite of constant improvement in processor technology, there are still applications that are computationally expensive. This will lead to the use of multiple DSP chips in multiprocessors as well as the development of special purpose chips for synthesis. All of these developments will be discussed in the following sections. 

Early approaches to music analysis relied on a running Fourier transform to measure sine-wave amplitude and frequency trajectories. This technique evolved into a filter-bank-based processor and ultimately to signal analysis/synthesis referred to as the phase vocoder [Flanagan and Golden, 1966], This section describes the history of the phase vocoder, its principles, and limitations that motivate sinusoidal analysis/synthesis. Other formulations and refinements of the phase vocoder are given in chapter 7. 

Fig. E6.2 The synthesis of an inverse screw extruder from building block 1. (a) The building block (b) a rotating solid cylinder forms the moving surface (c) the inner surface of a hollow cylinder forms the stationary surface. The result is a single roll processor without the channel block (d) the shallow channel is wrapped around the rotating shaft. The maximum length of the channel is set by the circumference of the shaft (e) a twisted channel relaxes the length constraint (f) cross section of an inverse screw processor.

Example 6.5 The Synthesis of the Disk Processor In this example, we once again take building block 1 and pair it with the flat face of a rotating disk to obtain a disk processor, as shown in Fig. E6.5a. As was the case in the roll pump, the inlet and outlet ports are cut into the... 

Fig. E6.6a The synthesis of the rotating cup pump from building block 2. (a) The building block (b) a rotating solid cylinder and a rotating hollow cybnder for the moving planes (c) the rotating elements are separated by a channel block with feeding and discharge ports shown on either side (d) side view of the processor where the rotating elements are combined into a rotating cup and a stationary cover plate closure holds the channel block.

Two cavitational devices manufactured by Five Star Technologies were used for synthesis and were the models CaviMax (a single-orifice processor, operating at a constant flow rate and variable pressures) and the CaviPro 300... 

Fig. 5. Diagram of a typical flow configuration for synthesis in the CaviPro 300 processor equipped with a double-orifice cavitation chamber. Metal salt solutions are metered into a precipitating agent just before the inlet to the high pressure pump. The pressure of the solution is then raised to between 1 and 200 MPa and passed through a set of two orifices that generate cavitating bubbles. The effluent is shown to recycle back to the reservoir containing the precipitating agent.

Fig. 10. Grain size and crystallographic strain data for the synthesis of titania using the CaviMax processor as a function of different orifice sizes used in the processor.

Several series of methanol synthesis catalysts were prepared by the coprecipitation of the appropriate metal salts in either Na2C03 or (NH4)2C03 using the CaviPro 300 (dual-orifice processor) at both high and low pressures. The experiments were carried out using a 0.152-mm first orifice while varying... 

By a simple mechanical adjustment in the orifice sizes, type of processor, or the head pressure, the cavitation bubble dynamics can be systematically altered. When catalyst synthesis is carried out under different conditions obtained by this type of adjustment, the structures and grain sizes of products... 

Fig. 14. XRD results for the synthesis of 2% Pd on zirconia-5 mol% alumina after 1373 K calcination using the CaviMax processor equipped with either the 1.85-, 2.06-, 2.41-, or 2.92-mm orifice. The corresponding classical preparation is illustrated at the top of the figure.

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