摘要:

A pulse pre-amplifier for use in the measurements of fast photoconduction decays less than 1 us has been constructed by using ultrafast operational amplifiers. A flat frequency response with little phase distortion is obtained over the range from DC to 10 MHz and the rise time is about 30 ns. The amplifier should be operated with batteries in order to reduce the disturbance from strong noises of a light pulse generator used for the sample illumination.

ISSN:1073-9149    

DOI:10.1080/10739147908543468

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An experimental system which provides computer control of the thermal desorption experiment is presented. Both the hardware and software used in this system are described. This system greatly simplifies the use of the thermal desorption technique to investigate the mechanisms of complex multiple product heterogeneous reactions and allows the effects of poisoning and coadsorption in these systems to be investigated.

ISSN:1073-9149    

DOI:10.1080/10739147908543469

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A completely digital generator for producing timing and sampling pulses adjustable in 1 mS increments for rapid-scan differential pulse voltammetry (DPV) when interfaced to a commercially available electrochemical analyzer is reported. The generator is a self-contained unit and costs about $100 to build. The design given is specifically intended to interface with the Princeton Applied Research Model 174 Electrochemical Analyzer (PARC 174), although it can be easily modified to work with any suitable commercial or non-commercial instrument. Using ordinary recorder read out and the PARC-174 signal processing electronics, direct and inverse DPV can be done at scan rates up to 200 mV/s with the same reproducibility and accuracy obtained with the scan rates usually used in DPV (2-10 mV/s). With faster read out devices, practical analytical measurements can easily be done at scan rates of 0.5 to 1 V/s.

ISSN:1073-9149    

DOI:10.1080/10739147908543470

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

Open tubular carbon electrodes were used for biamperometric measurements of iron (II) in the ferrocyanide/ferricyanide redox couple. This measurement was used to monitor dehydrogenase enzyme reactions by reaction of ferricyanide with reduced nicotinamide-adeninedinucleotide (NADH) in the presence of the enzyme diaphorase. Reagents and samples are mixed in a flowing stream and the electrodes are placed downstream to measure the extent of reaction after a constant time interval. Ethanol was determined by reaction with NAD in the presence of alcohol dehydrogenase (ADH), ferricyanide, and diaphorase. Optimum solution conditions for the above measurements are described.

ISSN:1073-9149    

DOI:10.1080/10739147908543471

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

A flow cell was constructed from plexiglass. The cell was designed to allow insertion and removal of a Clark-type oxygen membrane electrode. It was used in a flow system to amperometrically determine glucose and glucose oxidase via oxygen depletion. Hydrogen peroxide was determined by oxidation at +0.9 V vs. the silver/silver chloride electrode by removing the electrode membrane. Alternatively, a lead dioxide catalyst electrode was constructed and inserted into the cell to catalytically decompose hydrogen peroxide to oxygen, which was detected. Molybdenum (VI) was determined by its catalytic effect on the reaction between hydrogen peroxide and thiosulfate.

ISSN:1073-9149    

DOI:10.1080/10739147908543472

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

摘要:

An instrument has been designed and constructed for the semi-continuous monitoring of sulfuric acid mist. The instrument utilizes the selective condensation method of acid collection with a subsequent conductivity measurement of the aqueous isopropanol-acid solution. The instrument utilizes a heated quartz extraction probe, along with state-of-the-art electronics. The sampling rate can be varied and preset by use of a mass flow controller to assure isokinetic sampling. The instrument was designed to semi-continuously monitor sulfur trioxide-sulfuric acid mist in the tail gases of contact acid plants on an unattended basis.

ISSN:1073-9149    

DOI:10.1080/10739147908543473

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739147908543467

出版商:Taylor & Francis Group    

年代:1979

数据来源: Taylor