Depth sampling, uses

Comparison of intensities of As 3d and In 4d photoelectronic peaks characterized by similar photoelectrons escape depth, allows us to estimate changes in stoichiometry of the nearsurface zones of the samples. The results of the composition measurements at InAs surface during various stages of vacuum annealing are shown in Fig. 4. Increase in the annealing temperature up to (200 - 500) °C leads to the monotonous decrease of relative content of As and at the same time to a decrease in lifetime of minority charge carriers according to the results of electrophysical measurements. 

Let us take another example. At the U.S. Gulf Coast, the Pleistocene and the Upper Tertiary (Pliocene and Miocene) reach a thickness of more than 6000 meters. Nevertheless, the coaliflcation has only reached the stage of high volatile bituminous at this depth. This observation resulted from our studies of samples from a deep borehole located in Terrebonne Parish, La. By reflectance measurements on humic inclusions in claystones of the uppermost Middle Miocene encountered at a depth of 5440 meters, we obtained a mean value (under oil) of 0.95% reflectance, which is equivalent to the reflectance of vitrinites (out of deep boreholes) with 35-40% volatile matter (daf). On the other hand, we found low volatile bituminous coals (14-16% volatile matter, daf) at a depth of 5100 meters in a borehole in the Lower... 

Electrical pumps are a good alternative to traditional glass and brass samplers. They enable us to collect samples from a discrete depth directly into the sample containers using a measured length of the intake tubing. The appropriate pump type is selected based on the lift capacity and the analyte nature. Samples for VOC analysis may be collected with a pump at pump rate of lOOml/min. 

Because of increased interest in the position of the hydrogen sulfide boundary in recent years, the depth of this feature was studied carefully. It was found that the hydrogen sulfide with formal boundary of 0.3 iM appears in density layer ao = 16.10-16.20 kgm 3 [17,19,26,33,39,40]. According to [40] the concentration of hydrogen sulfide increases from its first appearance defined as 0.3 (jlM quasi-linearly to 300-400 m with a vertical gradient of 0.6-0.7 iM nr1. The more frequent sampling performed during the past few years has allowed us... 

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