Minimal composition variation

The major components CaO and MgO in dolomite have a minimal range indicative of very small variation in Ca/(Ca+Mg+Fe) ratios, whereas the minor elements such as SrO and MnO have a wide variation. Therefore trace components in carbonate minerals can be used as discriminant parameters to determine the origin of the carbonate rocks (cf. Yang LeBas 2004). Compositional variation of carbonate minerals from Chehelkureh on the basis of MnO or SrO (wt%) versus [Ca/(Ca+Mg+Fe)j (atoms per formula unit, a.f.u.) diagrams (Fig. 4) show that the MnO and SrO contents in dolomite-ankerite are higher than those in siderite-magnesite and accessory calcite. 

Discriminating Obsidian Sources When Compositional Variation is Minimal Sycan Marsh and Silver Lake, Oregon... 

Co-electron beam evaporation can give alloys of widely varying composition across a single substrate. This variation can be estimated by evaluating equation 16 for each source. One result predicted by this equation is that the composition variation can be minimized by keeping the spacing between the sources small. 

Although a Houdry plant has a minimum of three or four catalyst cases, the larger plants have multiple sets. A 17,000-barrel/day plant may have as many as 12 cases (134). In such a plant, the cycles are commonly staggered for example, with three catalyst cases on stream at once and a cracking period of 10 minutes, a freshly regenerated case may be brought on stream and another taken off stream every minutes (340). This technique minimizes the variation in composition of the cracked product ( synthetic crude ) caused by the decline in conversion during each cycle as coke accumulates on the catalyst. 

It is important that the position of the sample probe is known accurately if there is a considerable variation in the gas composition profile across fhe ducf [33], It is preferred that the measurements be made sufficiently downstream of flow disturbances like elbows or dampers to minimize the variation across the duct. If fhis is not possible as is the case when physical restrictions limit how the exhaust ducting can be run and where the measurements can be made, then more traverses are recommended. 

How and what to sample Plant samples are generally taken from the branches of the largest tree or shrub that is available for maximum depth of root penetration. To minimize seasonal variations in the metal composition of plant tissue twig material of at least a few years in age is recommended. 

More recently, the application of metabolomics to study the metabolite composition of fecal samples has appeared in the literature (Vitali et al., Jacobs et al. 2007). This method has proven to be a useful mode of assessing gut microbiota activity. Collection of fecal samples should be performed in a controlled fashion to minimize unwanted variation. 

Mant and Hodges [47] developed more quantitative selectivity parameters for peptide separations using RPLC for control de-novo design of synthetic peptide standards with the same (amino acid) composition and minimal sequence variation (SCMSV). They used a range of stationary phases (C8 and C18 alkyl, polar embedded, polar endcapped, ether-linked phenyl, and phenylhexyl) such as those already available for small molecules, further enhancing the universal value of... 

Mant CT, Hodges RS. Design of peptide standards with the same composition and minimal sequence variation to monitor performance/selectivity of reversed-phase matrices. J Chromatogr A 2012 1230 30-40. 

Figures 1 and 2 show the mineralogical composition of cements as a function of their calcination. Although precautions were taken to minimize the variation of temperature both within the chaige of marl fragments and each fragment itself, a variation does exist. Hence, any given cement will contain characteristics reflecting a small range of temperatures. However, these are likely to be much less than those observed by Weber et al. [1] in historic Roman cement mortars.

The traditional fabrication methods for the alu-minide fuels are fairly simple. The fuel fabrication waste volumes can be minimized. Several variations of the fabrication method of the aluminide fuel form have been successfully applied to produce Pu-Al composite fuel elements. Plutonium fabrication facilities currently exist at the Los Alamos National Laboratory and the Savannah River Site. These facilities could be used to produce Pu-Al composite fuel elements in sufficient quantities to verify fuel designs and prove the fuel performance. The Advanced Test Reactor at the INEL could be used to test these fuels. 

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