Determination of the effective depth of the liquid-vapor transition layer from the polymolecular adsorption isotherm

1977 ◽  
Vol 26 (10) ◽  
pp. 2035-2039
Author(s):  
V. A. Bakaev ◽  
M. M. Dubinin ◽  
E. Ya. Korchagin
Keyword(s):  
Adsorption Isotherm ◽  
Transition Layer ◽  
Polymolecular Adsorption ◽  
Effective Depth ◽  
Liquid Vapor

Determination of the Effective Depth for Double-Fiber Fluorometric Sensors

1992 ◽  
Vol 46 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Zhong Yuan Zhu ◽  
M. Cecilia Yappert
Keyword(s):  
Fiber Optic Sensor ◽  
Fluorescence Signal ◽  
Acceptance Angle ◽  
Fiber Sensors ◽  
Sample Depth ◽  
Effective Depth ◽  
Different Diameters ◽  
Semi Empirical ◽  
Analytical Expressions

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.

Étude de l'adsorption des hydrocarbures aromatiques polycycliques sur l'hydroxyde d'aluminium par chromatographie liquide à haute pression

1999 ◽  
Vol 77 (10) ◽  
pp. 1594-1598 ◽  
Author(s):  
Chakib Ameziane Hassani ◽  
Hugues Ménard
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Adsorption Isotherm ◽  
Surface Area ◽  
Aluminium Hydroxide ◽  
High Performance ◽  
Electrokinetic Potential ◽  
Physical Adsorption

A study by high performance liquid chromatography of adsorption isotherm of HAP in toluene on Al(OH)3 heated between 25 and 700°C shows that the rate of adsorption is maximal on the Al(OH)3 heated at 300°C. The measurement of electrokinetic potential and the surface area of adsorbants approve this result. The determination of adsorption enthalpies of different HAP on the aluminium hydroxide has shown the existence of physical adsorption. The adsorbing power of Al(OH)3 heated at 300°C is compared with that of other materials known or suspected very carcinogens.Key words: adsorption isotherm of HAP, aluminium hydroxide.

Study of a chemical-vapor-deposited diamond thin film on a molybdenum substrate by glancing incidence X-ray diffraction

2007 ◽  
Vol 22 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Jianfeng Fang ◽  
Jing Huo ◽  
Jinyuan Zhang ◽  
Yi Zheng
Keyword(s):  
Thin Film ◽  
Diffraction Analysis ◽  
Transition Layer ◽  
Chemical Vapor ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Thin Film ◽  
Chemical Vapor Deposited

The structure of a chemical-vapor-deposited (CVD) diamond thin film on a Mo substrate was studied using quasi-parallel X-ray and glancing incidence techniques. Conventional X-ray diffraction analysis revealed that the sample consists of a diamond thin film, a Mo2C transition layer, and Mo substrate. The Mo2C transition layer was formed by a chemical reaction between the diamond film and the Mo substrate during the CVD process. A method for layer-thickness determination of the thin film and the transition layer was developed. This method was based on a relationship between X-ray diffraction intensities from the transition layer or its substrate and a function of grazing incidence angles. Results of glancing incidence X-ray diffraction analysis showed that thicknesses of the diamond thin film and the Mo2C transition layer were determined successfully with high precision.

Determination of the adsorption film characteristics of alkyltriphenylphosphonium cations from time dependent capacitance measurements

1987 ◽  
Vol 52 (2) ◽  
pp. 308-315
Author(s):  
Anastos Anastopoulos ◽  
Anastasia Christodoulou
Keyword(s):  
Adsorption Isotherm ◽  
Surface Concentration ◽  
Time Dependent ◽  
Phosphonium Salts ◽  
Adsorbed Particle ◽  
Adsorption Film ◽  
Capacitance Measurements ◽  
Film Characteristics ◽  
Quaternary Phosphonium Salts

The determination of the adsorbed film characteristics at the interface between methanolic solutions of quaternary phosphonium salts and the Hg electrode is carried out by means of time dependent capacitance measurements. The maximum surface concentration, the area per adsorbed particle and the orientation of methyltriphenyl-, cyclopropyltriphenyl-, and n-butyltriphenylphosphonium cations are derived by two methods, the first of which is free of isotherm assumptions and the second involves an adsorption isotherm obeyed by the system under examination.

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