Systems, experimental description

Past studies of solid-solution aqueous-solution (SSAS) systems have focused on measuring the partitioning of trace components between solid and aqueous phases. The effect of solid-solution formation on mineral solubilities was rarely studied. Recently however, Lippmann (1,2), Thorstenson and Plummer (3) and Plummer and Busenberg (4) have enriched our understanding of SSAS systems with their theoretical and experimental descriptions of solid-solution dissolution and component distribution reactions. The objectives of this paper are 1) to describe and to compare the concepts presented by the above authors, 2) to present some techniques which may help estimate the effect of SSAS reactions on the chemical evolution of natural waters. 

N. Berezina, N. Gnusin, O. Dyomina and S. Timofeyev, Water electrotransport in membrane systems. Experimental and model description, J Membr. Sci., 1994, 86, 207-229. 

Acoustic wave device as LC detector amount of analyte in detector, 15,16/ chemical immobilization procedure, 13 chromatograms of blank and human immunoglobulin G samples, 13-15 chromatographic system, 11 continuous measurement ability, 15,17 experimental description, 11,13 limitations, 17 sensorgrams, 14/15 surface acoustic wave devices and electronics, 11,12/... 

Fig. 5 Theoretical and experimental descriptions of the impact of uptake inhibition (a) and enhancement of release (b) of the responses recorded at microdisk electrodes. Theoretical curves Numerical solutions of Eq. (3) were used to generate predicted concentration profiles at various times during a simulated period of stimulation. The calculated concentration profiles shown in the main panel of the top and bottom portion of this figure were obtained at the end of the simulated stimulus. The top panel shows how an increase in the Michaelis constant (/fm) changes the concentration profile, while the bottom panel shows the effect of an increase in the magnitude the simulated stimulus (further details can be found in Ref [25]). Stimulation responses The inset panels show experimental stimulus responses recorded in the rat brain with microdisk electrodes. Open circles denote the beginning and end of the electrical stimulation. Predrug responses (solid lines) were recorded prior to systemic administration of either 20 mg kg nomifensine (a) or 250 mg kg L-DOPA (b). Postdrug responses (dotted lines) were recorded 25 min after nomifensine administration or 55 min after L-DOPA administration. Note that the trends in the amplitude of the experimental signals correspond very well to those apparent in the theoretical concentration profiles.

This chapter describes the application and development of trace gas detection based on PTR-MS within life sciences. The chapter begins with a short overview about the ion chemistry that is used in these mass spectrometer systems to sensitively measure trace gases. The overview is followed by the experimental description of the system, including practical aspects such as how to perform a calibration or the use of natural isotopic ratios to gain some information about the identity of the detected compounds. The main part of the chapter deals with applications and measurements performed with PTR-MS to study processes inside plants, fruit, bacteria, and insects interactions between plants and pathogens and also as a tool for human health research. 

A model always means a more or less drastic simplification of some real system in order to describe or even to explain a phenomenon which is experimentally observed in that real system. A description of a phenomenon is a mathematical formulation of its constitutive variables, mostly in the form of a differential equation or a system of differential equations which contain the experimental parameters of the phenomenon as constants. An explanation goes beyond a pure description in that it reduces the occurrence of the phenomenon to more elementary relationships or laws which were known already. It is evident that the border line between a descriptive and an explanatory model is hazy and very often depends on the point of view. 

Amperometric glucose-sensing electrodes with modified enzymes enzyme electrode systems, 42-43 experimental description, 41 2 flow injection measurement of glucose for lipid-modified enzyme electrode, 44,45/,46f... 

The selection, scale-up, and design of the components that make up the mixing system are based on the fundamental and experimental descriptions of the hydrodynamics and mass transfer aspects of solids suspension discussed earlier. The following issues must be addressed ... 

The purpose of this monograph is to present in an integrated form a description of gas-solid reaction systems, where full account is taken of these new developments and where structural models of single particle systems, experimental techniques, the interpretation of measurements, the design of gas-solids contacting systems, and practical applications are treated in a unified manner. 

At first we tried to explain the phenomenon on the base of the existence of the difference between the saturated vapor pressures above two menisci in dead-end capillary [12]. It results in the evaporation of a liquid from the meniscus of smaller curvature ( classical capillary imbibition) and the condensation of its vapor upon the meniscus of larger curvature originally existed due to capillary condensation. We worked out the mathematical description of both gas-vapor diffusion and evaporation-condensation processes in cone s channel. Solving the system of differential equations for evaporation-condensation processes, we ve derived the formula for the dependence of top s (or inner) liquid column growth on time. But the calculated curves for the kinetics of inner column s length are 1-2 orders of magnitude smaller than the experimental ones [12]. 

This paper deals with the control of weld depth penetration for cylinders in gold-nickel alloy and tantalum. After introducing the experimental set-up and the samples description, the study and the optimization of the testing are presented for single-sided measurements either in a pulse-echo configuration or when the pump and the probe laser beams are shifted (influence of a thermal phenomenon), and for different kind of laser impact (a line or a circular spot). First, the ultrasonic system is used to detect and to size a flat bottom hole in an aluminium plate. Indeed, when the width of the hole is reduced, its shape is nearly similar to the one of a slot. Then, the optimization is accomplished for... 

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