Systematic sampling pattern

Modem analytical techniques such as secondary ion mass spectrometry (SIMS) and the electron microprobe allow chemical analysis with a spatial resolution of a few micrometers. In the few investigations that have been made, Sr and Mg are found to exhibit banding on the scale expected from the annual growth rate (Fig. 15). The data from Uamh an Tartair Cave in northern Scotland show Mg and Sr to vary in antiphase to each other. Data from Butler Cave, west central Virginia show Mg and Sr to vary in phase. Further, in the Butler Cave sample, the seasonal low concentrations are sharp downward spikes compared with the much broader high concentrations. The presence of a systematic annual pattern in Sr and Mg has been demonstrated for two examples. The interpretation of these results remains to be worked out. 

Assessment of the sampling pattern (i.e., random, systematic, or judgmental) Statistical evaluation of distribution parameters of the elements of interest Implementation of quality measures for the assurance of data quality Incorporation of a special depth function for element distribution, particularly for urban soils... 

Calcite cement is the dominant cement type in the central basin. Cemented zones can be visually recognized in cores and are from 10 cm to, in a few cases, more than 1 m thick (Boles Ramseyer, 1987). Cement zones cannot be easily traced between wells spaced as close as 100 m, suggesting that the intensely cemented zones are relatively isolated and discontinuous, certainly on a basin scale and in most cases on a reservoir scale. Most cement zones have not been studied in sufficient detail to establish growth patterns. A few detailed analyses of individual zones show that some have a composite history (i.e. variable isotopic compositions) on a scale of less than 0.5 m (e.g. cement zone at North Coles Levee, well NCL 488-29, 2621 m depth), whereas others show little variation (Schultz et al., 1989). Systematic growth patterns, such as are typical for concretions in shales (e.g. Raiswell, 1971 Boles et al., 1985) or in concretions that coalesce to form continuous cemented beds (Bjor-kum Walderhaug, 1990), have not been recognized in the zones studied to date. Apart from extensively cemented zones, calcite occurs as scattered crystals in many samples. 

In systematic sampling, samples are collected on the basis of a given geometric or time pattern, for instance, at some regular intervals of spatial location or time. Sometimes the segregation of population... 

Systematic sampling Starting from a randomly selected point, sampling follows a strict predefined sampling grid In comparison with random samphng, easier to implement in practice spatial contamination patterns may be overlooked... 

The LTT plot (Figure 17.2) allows comparison of the pattern of diversification of extant taxa in the pleurocarpous mosses with the equivalent curves for the angiosperms and polypod ferns as calculated by Schneider et al. (2004). Note that the shape of these plots is susceptible to differences in the sampling strategy (Nee et al., 1994 Pybus and Harvey, 2(XX) Shaw et al., 2003). Issues of systematic sampling bias were not explored by Shaw et al. (2003), who concentrated instead on the effect of randomized incomplete sampling, allowing them to accept or reject different models of diversification rates. 

The maximum search function is designed to locate intensity maxima within a limited area of x apace. Such information is important in order to ensure that the specimen is correctly aligned. The user must supply an initial estimate of the peak location and the boundary of the region of interest. Points surrounding this estimate are sampled in a systematic pattern to form a new estimate of the peak position. Several iterations are performed until the statistical uncertainties in the peak location parameters, as determined by a linearized least squares fit to the intensity data, are within bounds that are consistent with their estimated errors. 

Nance WB, Taylor SR (1976) Rare earth element patterns and crustal evolution—I. Australian post-Archean sedimentary rocks. Geochim Cosmochim Acta 40 1539-1551 Nishio Y, Nakai S (2002) Accurate and precise lithium isotopic determinations of igneous rock samples using multi-collector inductively coupled plasma mass spectrometry. Anal Chim Acta 456 271-281 Nishio Y, Nakai S, Hirose K, Ishii T, Sano Y (2002) Li isotopic systematics of volcanic rocks in marginal basins. Geochim Cosmochim Acta 66 A556... 

A modified Youden two sample quality control scheme is used to provide continuous analytical performance surveillance. The basic technique described by other workers has been extended to fully exploit the graphical identification of control plot patterns. Seven fundamental plot patterns have been identified. Simulated data were generated to illustrate the basic patterns in the systematic error that have been observed in actual laboratory situations. Once identified, patterns in the quality control plots can be used to assist in the diagnosis of a problem. Patterns of behavior in the systematic error contribution are more frequent and easy to diagnose. However, pattern complications in both error domains are observed. This paper will describe how patterns in the quality control plots assist interpretation of quality control data. 

A systematic study was conducted on clean Si(lll) surface with a clean W tip (Chen and Hamers, 1991). The entire curve of the dependence of the measured apparent barrier height, Eq. (8.27), with z-piezo displacement, was recorded. The experiment was performed under the condition that a clear 7X7 pattern was observed, which indicated that both the tip (near the apex atom) and the sample were clean. By carefully moving the tip back and forth, so as not to press into the sample surface too deeply, the entire process is completely reversible. The experimental barrier height measurements were performed using an ac modulation method, by applying a small 0.05 A modu-... 

The most obvious pattern among all the data concerned the difference between prehistoric and modem samples. A number of elements show either systematic increases or decreases in ppm concentrations between the modem and prehistoric shells. For example, Figure 7 plots Na and Ba as ratios Of % Ca. Relative to prehistoric samples, modem ones are systematically enriched in Na and depleted in Ba. Other elements that show such systematic changes include Ti, V, Mn, As, and Cd, where prehistoric samples tend to be enriched in these elements. Enrichment of some elements in prehistoric samples is likely the product of leaching of other elements over time (such as Na), thereby increasing the relative proportion of the former. 

The average PBDE congener patterns measured by Zhu and Hites [19] in the archived lake trout samples were similar to those presented in Fig. 7, and these average patterns from all five lakes were similar to each other, even though their absolute concentrations were different. However, these congener patterns changed with time. The proportion of BDE-47 was usually smaller in 1984 than in 1996, and the opposite was true for BDE-153. To explore this observation systematically, Zhu and Hites [19] defined the following ratio ... 

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