摘要:

A piezoelectric cell based on a bifurcated fiber optic has been designed and implemented for simultaneous photoacoustic and fluorescence measurements. The analytes were ethanolic solutions of anthracene. Quartz rod configurations were evaluated to reduce the amount of scattered light impinging on the piezoelectric crystal.

ISSN:1073-9149    

DOI:10.1080/10739149408003017

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Details are reported of the construction, calibration and testing of a fast-scanning spectrometer consisting of adouble-diodearrayopticalsimultaneousmultichannelanalyzer (DDA-OSMA) coupled to stopped-flow instrument. This set-up enables the recording of high quality absorbance spectra as well as absorbance-time traces as a function of wavelength, on a millisecond time scale. The electron-transfer reaction between Fe(CN)63-and L-ascorbic acid is used to demonstrate the performance of the system.

ISSN:1073-9149    

DOI:10.1080/10739149408003018

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The development of an automated method for the simultaneous determination of nitrogen oxides, aldehydes and ketones is described. All components are sampled together by means of impingers, which are filled with an acidified solution of DNPH in acetonitrile. The corresponding derivatives are separated and quantified by reversed-phase HPLC with UV detection at 300 nm or at 345 nm. Using this reproducible method calibration curves with a correlation coefficient of 0.999 could be obtained. The method was validated by means of several field tests, measuring candle smoke and cigarette smoke.

ISSN:1073-9149    

DOI:10.1080/10739149408003019

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

For the detection of the accidental leaks of toxic styrene vapors that occurred in polymer and plastics related industries, a simulation of the styrene vapors distribution and a smart sensor's network are proposed. To design a reliable system for the real time detection of the styrene vapors and to avoid a long time exposition of the workers, an optimal localization of the styrene sensors in the plant and the signal processing are studied. First, the dispersion of the styrene vapors versus the time and the environmental parameters such as gas velocity, pressure and wind direction, is examined. Then, the network protocols, such as signal processing of gas concentration provided by of each sensor, which will allow the multi-detection of the styrene vapors, is discussed by using the queuing theory. The Poisson's distribution signals would permit the calculation of the number of sensors or the estimate of the latency of the stations. To prevent danger and to increase workers' security in the plant, this new method can be used to control organic vapors' concentrations in the air.

ISSN:1073-9149    

DOI:10.1080/10739149408003020

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper describes the development of a low cost current follower, suitable for current measurements in the pico to micro-ampere range in general laboratory and field applications. The versatile instrument is designed for voltammetric measurements with ultramicroelectrodes, in a two-electrode cell configuration. The signal output can be monitored either by using an analog-to-digital converter or by a conventional electromechanical recorder. Performance tests in which the potential ramp and the signal current acquisition were performed using a digital-to-analog and analog to digital interface and an IBM-PC microcomputer are also described.

ISSN:1073-9149    

DOI:10.1080/10739149408003021

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A new design for the construction of an inexpensive and flexible temperature programmer for surface science applications is described.

ISSN:1073-9149    

DOI:10.1080/10739149408003022

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An isocratic Reversed - Phase High Performance Liquid Chromatographic (RP -HPLC) method is presented for the simultaneous determination of atropine sulphate and scopolamine-N-butylbromide. The analytes were separated on a Brownlee RP-18, Spheri-5, 220 × 4.6mm I.D. column with a mobile phase consisting of 0.05M ammonium acetate - methanol-acetonitrile (48:32:20 v/v). Flufenamic acid was used as internal standard and the analysis was completed within approximately 10 rnin. The detection was performed with a variable wavelength UV - visible detector at 220 nm resulting in detection limits of 18 ng of each alkaloid per 10 μl injection.

ISSN:1073-9149    

DOI:10.1080/10739149408003023

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739149408003024

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739149408003025

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:1073-9149    

DOI:10.1080/10739149408003026

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor