Profiling samples

Upper soil profile sample in liner with end caps... 

When investigating opaque or transparent samples, where the laser light can penetrate the surface and be scattered into deeper regions, Raman light from these deeper zones also contributes to the collected signal and is of particular relevance with non-homogeneous samples, e.g., multilayer systems or blends. The above equation is only valid, if the beam is focused on the sample surface. Different considerations apply to confocal Raman spectroscopy, which is a very useful technique to probe (depth profile) samples below their surface. This nondestructive method is appropriate for studies on thin layers, inclusions and impurities buried within a matrix, and will be discussed below. 

Profile Sampling section (m) Sampling interval (m) Number of samples... 

The podzol profile samples were taken from the groundwater catchment areas from humus (A0) eluvial (A) and illuvial (B) horizons and the parent material (C). In coarse-grained sand areas the profile waspoorly developed and mainly 20 cm thick, the thickness in till areas ranged from 40 to 80 cm. 

Figure 4. SEM photomicrograph of characteristic surfaces of sand grains from a Venezuelan soil profile. Samples from a) 90 cm deep, b) 40 cm deep. (Scale bar 2.5 microns).

The soil orientation survey consisted of three east-west traverses across the known areas of mineralization on the property at Pico Prieto and Venado and three soil profiles in the Venado area. The primary purpose of the soil traverses was to determine the spacing required to find a deposit of similar dimensions and style of mineralization, and to determine the optimum soil size fraction and pathfinder elements for these styles of mineralization. The purpose of the soil profile samples was to determine whether metal concentrations vary with soil horizon and depth. 

In 1979 and 1983 (9,10). The data Indicated that although penetration of herbicide and TCDD had occurred throughout the soil profiles sampled (8 cm Increments down to 32 cm), the bulk of the chemicals remained near the surface. Data from the microbial analyses of soil samples collected from the Herbicide Storage Areas confirmed that proliferation of certain microflora occurred under high levels of herbicide residue. 

Determination of the optimum time for which the SPME sorbent will be in direct contact with the sample is made by constructing an extraction-time profile of each analyte(s) of interest. The sorption and desorption times are greater for semi volatile compounds than for volatile compounds. To prepare the extraction-time profile, samples composed of a pure matrix spiked with the analyte(s) of interest are extracted for progressively longer times. Constant temperature and sample convection must be controlled. Stirring the... 

List the locations for special measurements and sample collections (e.g., depth profiles, sampling during drilling and during pumping tests). 

Several workers measured tritium concentrations in profiles of soil moisture. The samples were collected in most cases by means of a hand drill the profile samples were carefully wrapped to avoid drying or exchange with tritium in the air. In the laboratory the soil moisture was extracted by distillation, weighted (to get a moisture profile), and measured for the tritium concentration. 

Given that flowstone and stalagmites may provide relatively continuously time lines that can be accurately calibrated by U/Th dating, it is possible to extract paleoclimatic signals beyond the bulk deposition of the calcite itself. This has been accomplished by tracking various isotope and trace element profiles. Samples can be drilled at sufficiently close intervals along a sawed slab of stalagmite or flowstone to provide profiles with a time resolution of a few tens to a few hundred years. 

Figure 3.17. Computer-simulated resist profiles (SAMPLE). Operating input parameters include matched substrate, AZ1350J resist, 4358 A, 90 mjlcm, NA = 0.35, a = 9.99, defocus 0.0, development 80 s. The open image (B = 0.058) simulates AZ1350J performance. The shallow profile (B = 1.96) was generated from identical input parameters with the exception that the un-bleachahle absorbance (B) was adjusted to the value corresponding to the absorbance of 1 xm of novolac at 254 nm. (Reproduced with permission from reference 37. Copyright 1981 Institute of Electrical and Electronics Engineers.]...

Figure 15. Copepod and chlorophyll profiles sampled at 1900 h (a) and the corresponding estimated production profiles (b) from the Peruvian shelf at 9° S. The vertical chlorophyll structure shows both a surface and subsurface...

Table V. Extractable Organic and Nonvolatile Hydrocarbons in Profile Sampling at Bermuda Station"...

Basil Philhps (Exxon International Co.) and D. E. Brandon (Exxon Production Research Co.) assisted in developing the sampling procedures. W. Broecker and John Goddard of the Lamont-Doherty Geological Observatory of Columbia University helped to evaluate profile sampling and other aspects of the work. Laboratory work was carried out by D. E. Bachert and W. D. Henriques. 

Figure 2-33 shows the results along a profile sampled at intervals of 5-20 m across known sulphide mineralisation in quartz veins in late Palaeozoic igneous rocks covered by 60 m of Quaternary sediments. Conventional geochemical survey data fail to detect the mineralisation (Fig. 2-33A). The MPF results, on the other hand, give well-defined anomalies for gold, arsenic, silver and copper (Fig. 2-33B).

Figure 10.9 Comparison between the band profiles predicted by the ideal model and the numerical solution of the equilibrium-dispersive model for a Langmuir isotherm. Constant column efficiency, 2000 theoretical plates, (a) Classical C vs. f profile. Sample size given as loading factor, (b) Reduced profiles, plots of bC vs. (t — fo)/(fR,o — to)- Sample size given as apparent loading factor, m = [Icq/(1 + J q)] NLj. Similar chromatograms, corresponding to intermediate loading factors, are given in Figure 10.8.

Profile samples are generally collected with bottles using conventional... 

In atmospherically exposed concrete there is no easy initial or surface concentration as the chlorides at the surface can vary from zero to 100% depending upon wetting, drying, evaporation, wash off, etc. It is therefore common practice to discard the first 5-10 mm of a chloride profile sample and take the next increment, around the 10 mm depth, as a constant initial, pseudo surface concentration. If this is done then diffusion calculations must use the depth from the sampling depth, not from the surface. 

In a typical run, a glass test tube is loaded with the proper amounts of reaction components (momomer(s), initiator and/or catalyst, and -when necessary- additive(s) and/or solvent). FP is triggered by heating the upper end of the tube with a soldering iron tip. A thermocouple probe linked to a digital temperature reader is used for recording temperature profile (sampling rate 1 Hz). 

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