Column selector

Column selector valves can be added on as accessories to allow column switching for multi-dimensional chromatography (to increase the resolution of very complex samples such as in proteomics) or for automatic column selection (up to six columns) to facilitate methods development using different columns. 

In the 12-vessel extractor unit, two air actuated solenoids (60 PSI each) have been used to actuate the column selectors. This provides maximum independence between the two column sets. However, one solenoid could be used with an increased air pressure (80 PSI) for the operation. 

With our design, there are two ways by which the selectors could be utilized to conduct extractions from a number of columns. The first utilizes a concurrent 2N non-stop mechanism, where N is the number of extractions vessels per column switching valve, for actuation and column selection. The second utilizes a concurrent 2N-1 stop mechanism. N is equivalent to the number of vessels. Thus, in the 2N mechanism, and for two tandem column selectors, 12 vessels can be selected. In the 2N-1 mechanism, 11 vessels can be selected. 

Generally, this mechanism could be extended to accommodate any number of vessels with ease. For example, if 60 vessels were desired, 5 column-selector valves and 5 solenoids would be needed. Size limitations with regard to pump volume (or type, a reciprocating pump would not have a volume limitation) and oven size would be have to be overcome. 

With the 12-vessel extractor, the 1/8" valve receives the extraction effluent from the vessels in tandem column selectors 1 and 2 (TCS-1 and TCS-2) into two separate ports 1 and 4 as shown in Figure 7. During the static mode, the counter-current valves, i.e. modifier pump valves (MP-3 and MP-4) are closed. Pressure build-up for static extraction then follows. Valves MP-3 and MP-4 are mounted close to the ports so that no accumulation of extract occurs. The valves are connected via a stainless steel tee (T2), to the modifier pump which is also used for flushing the lines after the extractions have been conducted. In the dynamic mode, extract flows from the unblocked ports of 1 and 4 to ports 5 and 6 then through to the delivery nozzles. 

Figure 16.3 shows a circuit diagram of an electronic artificial skin system. Integrated circuits are formed by organic transistors with a pentacene channel layer this has p-type conduction and consists of sensor matrix, column selector, and row decoder. The manufacturing process flow of the sensor matrix has been described above other circuits are processed similarly. 

Fig. 16.3. Circuit diagram of electronic artificial skin consisting of a 16 x 16 access transistor matrix, column selector, and row decoder. The manufactured transistor with pentacene channel layer has p-type conduction. R0-R3 are row addresses, C0-C1 are column...

Carbon Dioxide, Ethylene, and Ethane in Nitrogen Mixtures Using Column Selector, /. Chromatogr. Sci. (1970) 8(4), 224-226. 

Multi-solvent pumps, photodiode array detectors (PDA), modeling software, automated development systems, and multi-column selector valves... 

In order to realize the cut-and-paste feature, all the circuits of the system must be scalable in size. The access FET matrix is scalable because it is a simple repetition of senseis. The FET matrix can be cut to any required size. We have also developed row decoders and column selectors that are equally scalable. 

FIGURE 6.3.6 A measured waveform of electronic artificial skin. When pressure is applied to the sensor matrix, the pressnre-sensitive mhher becomes condnctive and bit line is pulled up to the supply voltage. (1) The input signals of column and row addresses. (11) The activation signal of the row decoder and column selector. (Ill) The measured waveform. The decoder output (word line) and bit output (bit line). 

If a quaternary low-pressure gradient system and a six-column selector are available, a two-eluent-six-column combination can be tested overnight For the four mixer chamber inlets use, e.g., the following MeCN, acidic water, basic water, rinsing liquid, e.g. ... 

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