摘要:

A versatile digital counter-timer circuit is described. The circuit simultaneously times and counts TTL pulse events in a single experiment under either timer or events counter control, or independently times and counts events in separate experiments. The total time duration (1 μs-999,999s) or total desired number of event pulses (1-999,999) can be preset by means of a 6-digit BCD switch. Initiation of the experiment controls both a timer relay and an events relay. When the preset timer or pulse count is reached, the corresponding relay is reset, allowing control of experiments. Applications to spectroelectrochemical coulometric titrations of cyfochrome c and methyl viologen are described. Applications to additional techniques such as anodic stripping voltammetry are suggested.

ISSN:1073-9149    

DOI:10.1080/10739148108543521

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A microcomputer has been interfaced to a mass spectrometer for the automatic acquisition of data and subsequent processing of the data to obtain an analytical report of sample composition. The single-board construction of the computer chosen facilitated the realization of a cost-effective solution for this application. The simplicity of the interfacing now required to add automation to labor-intensive operations should encourage wider application of microcomputers in laboratories where minimal hardware support exists.

ISSN:1073-9149    

DOI:10.1080/10739148108543522

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Fourier transformation techniques are applied to high resolution laser spectra of water vapor to identify undesirable spectral features. Features such as interference fringes can be mathematically filtered from spectral information in the Fourier domain and the spectral data recovered by an inverse Fourier transformation. The combined use of second derivative detection and the Fourier transformation leads to significant enhancements of spectral information relative to both lower and higher frequency background interferences without a significant loss of resolution.

ISSN:1073-9149    

DOI:10.1080/10739148108543523

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A versatile and easy-to-build digital function generator for electrochemical applications is described. The instrument combines a 16 bit digital to analog converter (DAC) with digital control of the switching. Possible waveforms are ramp and asymmetrical or symmetrical triangle in single cycle or continuous mode. In the latter modes a timed delay at steady potential can be incorporated at the point of slope reversal. This is interesting for use in cyclic voltammetry to measure the reverse peak current when several electroactive species are present in solution.

ISSN:1073-9149    

DOI:10.1080/10739148108543524

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The programmable integrator is a digital instrument used for estimating the area or coulombs rapidly and accurately in any portion of I-t curve (current-time). There are two ways by which programming can be done. In the first method, the scanning potential limits have to be set, The instrument measures the coulombs directly irrespective of scan rate. Integration can be carried out on any I-t curve which is got by varying sweep signal in a programmed mode. In the second method, starting potential and period of integration have to be set. Integration will be carried out from the instant the sweep reaches the starting potential for the programmed time period.

ISSN:1073-9149    

DOI:10.1080/10739148108543525

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Propylthiouracil (2-thio-4-oxo-6-propy1-1,3-pyrimidine) reacts with sodium nitroprusside in presence of sodium hydroxide, and on treatment with acetic acid it gives a greenish blue color measurable at 600 nm. The effects of pH, time, concentrations of sodium nitroprusside, sodium hydroxide and acetic acid have been studied. The developed color is used as a basis of a colorimetric method for the determination of pure propylthiouracil and in pharmaceutical formulations. The method can be adopted for concentrations ranging from 8 to 32 μg per ml with 100% ± 2.0 accuracy.

ISSN:1073-9149    

DOI:10.1080/10739148108543526

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The Fisher Sub-Sieve Sizer, one of the most widely used instruments, is characterized by its poor readability in the high porosity, low micron region. In this region readings are not only prone to subjective operator errors, but they become impossible to determine in low micron ranges (below 2 microns approximately). The method proposed in this article eliminates this difficulty, and extends the readability to as low as 0.4 microns without any alteration of the instrument itself. This makes it possible for any user of the Sub-Sieve sizer to greatly extend the capability of his instrument.

ISSN:1073-9149    

DOI:10.1080/10739148108543527

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor