Multiplexed columns

In the infrared, the light sensitive material is bump bonded at each pixel to a silicon multiplexer that amplifies the charge and multiplexes the outputs to external electronics, as shown in Fig. 17. The column and row boundaries are... 

Injection pump. An injection pump is used to force the waste into the injection zone, although in very porous formations, such as cavernous limestone, the hydrostatic pressure of the waste column in the well is sufficient. The type of pump is determined primarily by the well-head pressures required, the volume of liquid to be injected, and the corrosiveness of the waste. Single-stage centrifugal pumps are used in systems that require well-head pressures up to about 10.5 kg/cm2 (150 psi), and multiplex piston pumps are used to achieve higher injection pressures. 

The first reported case of timesharing for a mass spectrometer9 involved the design of an Ionspray interface with multiple sprayers to support the analysis of effluents from multiple columns. This approach led to the development of a multiplexed electrospray interface (MUX)10 using an LC/MS interface and multiple (identical) sprayers linked to a HPLC system and a spinning screen to allow the output of only a single sprayer to enter the MS (Figure 4.5). The injections of the HPLC systems... 

This assay can be a stand-alone approach, or can be coupled with different chromatographic or detection techniques such as column switching, parallel analytical columns, or multiplex electrospray sources. 

Bayliss and co-workers [10] combined ultra-high flow rates, parallel LC columns, a multiplex electrospray source, and mass spectrometric detection for the rapid determination of pharmaceuticals in plasma using four narrow bore (50 mm x 1 mm, 30 pm Oasis HLB) or capillary (50 mm x 0.18 mm, 25 pm Oasis HLB) HPLC columns with large particle sizes (to avoid high system back-pressure) in parallel with a multiple probe injector and a MUX MS interface. Small sample aliquots were injected directly into the system without sample pre-treatment procedure, obtaining very low limits of quantification (from 1 to 5 ng/mL). 

Multiplex systems have an array of electrodes on one of the substrates that addresses the rows, and another set on the other substrate that addresses the columns. 

Metal ohmic contact pads 55 are formed on the n-type islands and the detector is bonded to a multiplexer integrated circuit substrate 53 via indium columns 54. 

A small TN LC display can be multiplexed without the use of additional elements, because a nonlinear relationship exists between contrast and voltage, as shown in Fig. la. An addressing scheme such as shown in Fig. 2 can then be employed. Information is written into the display one row at a time. The row to be addressed is pulsed to +2 F, where Fis a suitable voltage, while all other, nonactive rows, are set to zero. Elements along a given row are addressed concurrently, by setting the columns at —1 For +1Fdepending whether a pixel is to display information or not, respectively. After the row is written, row potential is returned to zero and the next line is addressed. Polarity is reversed between frames to minimize deterioration of the LC by electrolytic processes. 

Figure 5 Schematic of a complete multiplexed and integrated instrumental design with eight capillaries. Stars at I, U1, and U2 represent the multiplexed freeze/ thaw valves. The T-assembly is made up of eight pieces of commercial junctions stacked together. These connect to the manifold M1, the SEC (size-exclusion chromatography) purification columns, and the reaction loops. The cross-assembly is made of eight pieces of standard crosses packed together with built-in heaters. V8 is an eight-position motorized titanium valve with a center port. S1 is a two-position motorized PEEK valve. V6 is a six-position motorized PEEK valve. (Reprinted from Ref. 33 with permission.)...

Fig. 4. Schematic representation of a commercial parallel LC/MS system. Liquid flow is delivered to eight columns by a pump and a flowsplitter. Peaks are detected by a multichannel UV detector and a TOF mass spectrometer with a multiplexed electrospray source...

Figure 2.14 Schematic representation of the pixels, made up of a pattern of orthogonal rows and columns of electrodes, of an LCD with multiplexed addressing.

Multiplex addressing with M electrode columns and N electrode rows allows M X N pixels to be created driven by M + N connections made at the end of each row and column, see Figure 2.14. This type of addressing allows large-area, high-information-content LCDs to be produced with acceptable contrast and viewing angles, see Chapter 3. 

In an LCD with multiplex addressing, parallel rows and columns of elec-... 

OLEDs can be addressed in a similar fashion to LCDs, see Chapter 2, i.e. directly with segmented electrodes, see Figure 4.8, by multiplexed addressing with rows and columns of electrode strips, see Figure 4.9 and by active matrix addressing with one transistor at each pixel, see Figure 4.10. The major... 

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