In situ locating

Strebel R., Huth J., and Hoppe P. (2000) In situ location by cathodoluminescence and SIMS isotopic analyses of small corundum grains in the Krymka meteorite. In Lunar Planet Sci. XXXI, 1585. The Lunar and Planetary Institute, Houston (CD-ROM). 

Once the site has been described in terms of the spatial distribution of specific pollutants, the analytical tasks associated with remediation and post-closure typically require frequent and repetitive analysis at specific locations for particular compoimds of interest. Because biosensors show the potential to operate continuously at remote or in situ locations, these devices could be particularly well suited for this task. For example, in many cases during remediation procedures on-site, real-time monitoring may be required to prevent off-site contamination of groundwater, especially where flow patterns are quickly and dramatically altered as a result of remediation procedures such as soil excavation, treatment, and backfilling. 

From this result we feel that the most likely In situ location for the enzyme In this tissue Is the ER. Explanations of what Is happening upon Isolation Include the disruption of the endoplasmic reticulum, thereby breaking It Into high density and low density fractions, with the chollnephosphotransferase being located In the low density band or the disruption of the normal enzyme attachment to the ER, thereby allowing It to associate with some other low density membrane fraction. In either case, the occurrence of the activity In the low density fraction appears to be an artifact and care must be taken In Interpretation of such results from this and other tissues as being a part of another organelle. 

Carbonate rocks are not normally transported over long distances, and we find carbonate reservoir rocks mostly at the location of origin, in situ . They are usually the product of marine organisms. However, carbonates are often severely affected by diagenetic processes. A more detailed description of altered carbonates and their reservoir properties is given below in the description of diagenesis . 

A wide variety of particle size measurement methods have evolved to meet the almost endless variabiUty of iadustrial needs. For iastance, distinct technologies are requited if in situ analysis is requited, as opposed to sampling and performing the measurement at a later time and/or in a different location. In certain cases, it is necessary to perform the measurement in real time, such as in an on-line appHcation when size information is used for process control (qv), and in other cases, analysis following the completion of the finished product is satisfactory. Some methods rapidly count and measure particles individually other methods measure numerous particles simultaneously. Some methods have been developed or adapted to measure the size distribution of dry or airborne particles, or particles dispersed inhquids. 

The diffusion, location and interactions of guests in zeolite frameworks has been studied by in-situ Raman spectroscopy and Raman microscopy. For example, the location and orientation of crown ethers used as templates in the synthesis of faujasite polymorphs has been studied in the framework they helped to form [4.297]. Polarized Raman spectra of p-nitroaniline molecules adsorbed in the channels of AIPO4-5 molecular sieves revealed their physical state and orientation - molecules within the channels formed either a phase of head-to-tail chains similar to that in the solid crystalline substance, with a characteristic 0J3 band at 1282 cm , or a second phase, which is characterized by a similarly strong band around 1295 cm . This second phase consisted of weakly interacting molecules in a pseudo-quinonoid state similar to that of molten p-nitroaniline [4.298]. 

Deuterioboration is one of the most important recent additions to the array of methods for saturating double bonds with deuterium. The easy accessibility of metal deuterides (lithium aluminum deuteride or sodium borodeuteride) facilitates the in situ preparation of deuteriodiborane which reacts with steroidal double bonds with a high degree of site and/or stereospecificity, depending on the location of the double bond. " ... 

In the reductive regime, a strong, apparently irreversible, reduction peak is observed, located at -1510 mV vs. the quasi reference electrode used in this system. With in situ STM, a certain influence of the tip on the electrodeposition process was observed. The tip was therefore retracted, the electrode potential was set to -2000 mV, and after two hours the tip was reapproached. The surface topography that we obtained is presented in Figure 6.2-14. 

Experience in PTC with cationic catalysts showed that, in general, the most suitable compounds have symmetrical structures, are lipophilic, and have the active cationic charge centrally located or sterically shielded by substituents. For anionic catalysis sodium tetraphenylborate fulfills these conditions, but it is not stable under acidic conditions. However, certain derivatives of this compound, namely sodium tetra-kis[3,5-bis(trifluoromethyl)phenyl]borate (TFPB, 12.162) and sodium tetrakis[3,5-bis-(l,l,l,3,3,3-hexafluoro-2-methoxy-2-propyl)phenyl]borate (HFPB) are sufficiently stable to be used as PTC catalysts for azo coupling reactions (Iwamoto et al., 1983b 1984 Nishida et al., 1984). These fluorinated tetraphenylborates were found to catalyze strongly azo coupling reactions, some of which were carried out with the corresponding diazotization in situ. 

Stimulated by extensive research activities on donor/acceptor substituted stilbenes, Mullen and Klarner have reported a donor/acceptor substituted poly(4,4 -biphenyl-diylvinylene) derivative (85) in which the NR2 donor and CN acceptor substituents are located on the vinylene unit [111]. The synthesis is based on a C-C-coupling reaction of in situ generated carbanion functions with a (pseudo)cation function, followed by a subsequent elimination of MeSH with formation of the olefinic double bond. 

Lyden et al. [92] used in situ electrical impedance measurements to investigate the role of disorder in polysulfide PEC with electrodeposited, polycrystalline CdSe photoanodes. Their results were consistent with disorder-dominated percolation conduction and independent of any CdS formed on the anode surface (as verified by measurements in sulfide-free electrolyte). The source of the observed frequency dispersion was located at the polycrystalline electrode/electrolyte interface. 

In situ XRD spectra were collected on beam line X18A at the National Synchrotron Light Source (NSLS) located at Brookhaven National Laboratory (BNL). The X-ray wavelength (X) was 1.195 A. The step size of the 29 scan was 0.02° in the regions with Bragg reflections and 0.05° in the regions without reflections. The XRD spectra were collected in the transmission mode (Liu et al., 2004). 

Despite the wealth of information on siderophores, there is still considerable debate as to how they function in the plant rhizosphere and the degree to which they accumulate in soils. Much of this debate has been due to inadequate methodology for detecting siderophores at microsite locations in the rhizosphere and the lack of analytical methods for in situ study of the interaction of siderophores and other iron mobilizing substances. Using simplified systems in the laboratory, it is possible to examine many different scenarios as to how siderophores might function. Yet, for the most part, there is still almost no information... 

Fig. 8.30 The Instrument Deployment Device (IDD) above the surface of Mars, showing all the four in situ instruments left) the MIMOS II with its contact ring can be seen in the front picture taken at Meridiani Planum, Mars right) MIMOS II is located on the left side picture taken at Gusev Crater, Mars...

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