Buried marker

In other parts of the world, a synthetic grass mat has been used to collect current-borne sediments enabling a protective mat of sand to accumulate. In Boa Vista, Cape Verde Islands the natural seabed is composed of water-worn pebbles of volcanic rock. These are easy to handle underwater and a layer of 100 mm pebbles overlain with some well-chosen boulders protects the site from marine and human interference. The insertion of a short tail of orange cord serves as buried marker. It is discrete, moving gently in the current, and to the casual intruder is much like other marine growth and debris. 

X-ray reflectometry (XR) has already been described in Sect. 2.1 as a technique for polymer surface investigations. If a suitable contrast between components is present buried interfaces may also be investigated (Fig. 4d) [44,61,62]. The contrast is determined by the difference in electron density between materials. It is, in the case of interfaces between polymers, only achieved if one component contains heavy atoms (chlorine, bromine, metals, etc.). Alternatively the location of the interface may be determined by the deposition of heavy markers at the interface. 

Enzyme structure may be studied by fluorescence spectroscopy [238-244]. Excitation in the 280-310 nm absorption bands of proteins, usually results in fluorescence from tryptophan (Trp) residues in the 310-390 nm region. The fluorescence from the Trp residues is a convenient marker for protein denaturation and large decreases or red-shifts in fluorescence are observed when proteins are denatured. These changes are most often due to the exposure of the Trp residues that are buried in the protein and may be due to the changes in the proximities of specific residues that may act as fluorescence quenchers. Fluorescence emission characterization of the immobilized... 

This could be measured by observing the separation of inert markers buried in each crystal opposite one another across the boundary. 

Hair as a marker of exposure to toxicants has been of considerable interest to toxicologists for more than a hundred years. Casper reported in 1857 the analysis of hair for the detection of poisons in his famous Practisches Handbuch der gerichtlichen Median. He referred to Hoppe-Seyler, who had found arsenic in the hair of an 11-year-buried body and had discussed the possibility that the metal was incorporated before death. About 100 years later, the first report about the detection of an organic drug in hair was published. Goldblum et al. described an ultraviolet method to detect barbiturates in guinea pig hair. 

Modified remnants of humic substances are found in buried soils (paleosols) of all ages. This organic matter, or paleohumus, is of interest in geology and pedology because of its importance as a stratigraphic marker and as a key to the environment of the geologic past. The occurrence of dark-colored humus... 

Soil is a special kind of sedimentary deposit produced in situ by the weathering of the earth s surface. Weathering refers to the chemical and biological processes that operate to breakdown and change the surface of the earth, altering its color, texture, or composition. These processes include rainfall, frost, and plant and animal activity as major forces of change. Soils are not only found on the surface of the ground. Old soils can be buried by later deposits. Buried soils provide a useful marker of the location of former land surfaces. 

The Oak Ridge National Laboratory has been burying solid wastes on site for many years. Trenches 10 X 200 X 15 feet deep, are dug. Packaged trash and equipment, can be transferred into the trenches from the backs of trucks, by a crane. The trenches are then backfilled with 3 to 4 feet of earth. Occasionally, auger holes 1 foot in diameter and 15 feet deep are dug, for the disposal of especially radioactive pieces of equipment. The use of an auger hole reduces the back-scatter of radiation to the bulldozer operator. The area is gridded and recorded, and this procedure is followed both for permanent marker purposes and for the occasional recovery of valuable equipment after burial. 

In trenching installations, a trench is dug in the earth to an appropriate depth, usually 75 cm or more, and the cable or cables placed into it. The minimum depth of the trench used depends on a number of factors, but deeper is generally better from a protection standpoint. However, deeper trenches are also proportionally more expensive to make. The trench is then backfilled with a variety of materials to protect the cable, such as clean sand or soil. Direct buried installations are typically marked with tapes laid parallel to the cable, but placed closer to the surface, and markers located visibly above the surface, in an effort to prevent dig-ups. Buried cables are typically connected to one another via hermetically sealed closures located in buried hand holes or manholes along the route. These closures house and protect the splices or connectors used to connect sections of cable. 

Fe(III) atom in the heme center (oxidation state marker band at 1373 cm ). At the same time, a mixture of both oxidation states in the spectra was observed and refers to a third group. Consequently, the tip was probably located right between two Cc molecules with different oxidation states. It should be noted that no direct contact of silver particle (at the TERS tip) and Cc was possible because the protein is buried in the lipid layer, whose contributions could also be identified in the spectra and actually is even domination of the spectral features. 

Figure 16 Average detection and localization (lateralization) thresholds, expressed as logic of the percentage in solution, standard error of the mean (s.e.m.) (those for lateralization are buried within the marker and cannot be seen), across the age range of subjects, grouped by decade. (From Ref. [28].)...

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