Computer controlled, thermostatted

First, the starter is heated to around 90 °C to separate the DNA double helix into single strands (a cfp. 84). The mixture is then cooled to allow hybridization of the primers (b). Starting from the primers, complementary DNA strands are now synthesized in both directions by the polymerase (c). This cycle (cycle 1) is repeated 20-30 times with the same reaction mixture (cycle 2 and subsequent cycles). The cyclic heating and cooling are carried out by computer-controlled thermostats. 

Freshly assembled lithium/carbon coin cells typically have voltages between 2.8 and 3.4 volts. The cells are in their fully charged state which means that no lithium is inserted in the carbon anode. Then the coin cells are tested with computer-controlled constant-current cyclers having currents stable to 1%. The cells are placed in thermostats at a particular set temperature v/hich is stable to 0.1°C during the test. Most of our cells were tested at 30°C. 

Measurements of pressure-area (jc-A) isotherms and transfers of monolayers on a substrate were carried out by using a computer-controlled film balance system (San-Esu Keisoku, Co., Fukuoka, FSD-20). Maximum surface area on the trough was 475 X 150 mm2. The trough surface and the moving barrier were coated with Teflon, and the subphase was temperature-controlled with a thermostat (20 0.5 °C). The concentration of lipid solutions was 1 mg/ml and the spreading amount of lipid solutions was 50 - 150 pi. After solvent evaporation, the monolayer was compressed at the speed of 0.60 cm2 s-i. Measurements of n-A isotherms and transfers of monolayer on a QCM substrate were performed automatically with the usual manner [26,27]. 

All polymerisations were carried out in nitrogen purged xylene solutions in a thermostatically controlled one litre glass reactor. Semi-batch processes were carried out in a similar reactor which was provided with calibrated peristaltic pumps (computer controlled when necessary) for delivering the monomer feeds. Typically, experiments were carried out at 80°C with monomer concentrations which gave solids contents in the range 10 - 60% at 100% conversion. 

The automatic apparatus consists of a viscosimeter and phototran-sistorized sensing devices mounted in a precision thermostat ( 0.005°C) connected to a cooled prethermostat ( 0.1°C). The base apparatus is commercially available (Schott Viscotimer, Jenaer Glaswerk, Schott Gen., Mainz), but the viscosimeter control functions and the time measurements are performed by using an electronic computer-controlled interface. This modification enables one to follow slow reactions and to reduce standard errors on the outflow times to 2 msec. The final results are evaluated numerically by an on-line computer-plotter system. 

Reactor and Reactor Conditions. A 5-litre glass reactor (15 cm diameter) fitted with four stainless steel baffles (10 cm x 1.5 cm) immersed in a thermostatted oil bath at 80 °C (reflux temperature of methyl acrylate) was used for polymerisation. Stirring was by means of a marine type impeller (6 cm diameter and pitch 45°). The overall reaction rate was sufficiently slow to ensure isothermal conditions. Additions of solutions of the more reactive monomer (styrene, of molar concentration 0.8) to the reactor were made using a computer controlled positive displacement pump (Precision Metering Ltd.) with four long-stroke pump heads, 90 out of phase to minimise pulsation of the flow. 

A typical laboratory preparation recipe for this coprecipitation route is provided hereafter. The experimental setup consists of a computer-controlled automatic titrator, a syringe pump, and a reactor, heated by a thermostat. 

FIA star 5010 Modular, semi- or fully automatic operation. May be operated with process controller microprocessor. Can be set up in various combinations with 5017 sampler and superflow software which is designed to run on IBM PC/XT computer 60-180 samples h Dialysis for in-line sample preparation and in-line solvent extraction.Thermostat to speed up reactions. Spectrophotometer (400-700nm) or photometer can be connected to any flow through detector, e.g. UV/visible, inductively coupled plasma, atomic absorption spectrometer and ion-selective electrodes... 

All modern heat flow calorimeters have twin cells thus, they operate in the differential mode. As mentioned earlier, this means that the thermopiles from the sample and the reference cell are connected in opposition, so that the measured output is the difference between the respective thermoelectric forces. Because the differential voltage is the only quantity to be measured, the auxiliary electronics of a heat flux instrument are fairly simple, as shown in the block diagram of figure 9.3. The main device is a nanovoltmeter interfaced to a computer for instrument control and data acquisition and handling. The remaining electronics of a microcalorimeter (not shown in figure 9.3) are related to the very accurate temperature control of the thermostat and, in some cases, with the... 

Figure 3.3-5. Stopped flow apparatus [19]. a, Syringe type pump b, thermostat c, mixing cell d, reaction cell e, stop syringe f, switch g, photo multiplier h, monochromatic filter i, lamp j, controller k, transducer 1, computer.

The SFC systems are grouped into two categories analytical SFC for chemical analysis and preparative SFC for scale-up chemical synthesis and purification. On a fundamental level, the instrumentation for SFC consists of the following (1) a fluid delivery system with high-pressure pumps to transport the sample in a mobile phase and to control the pressure (2) the column in a thermostat-controlled oven where the separation process occurs (3) a restrictor to maintain the high pressure in the column (4) a detection system and (5) a computer to control the system as well as to record the results (see Figure 9.5 as an example). In SFC the mobile phase... 

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