The Elimination Strategy

Take advantage of being able to mark in yonr test booklet. As you go through the + questions, eliminate choices from consideration by marking them out in your test booklet. Mark with question marks any choices you wish to consider as possible answers. See the following example  

This technique will help you avoid reconsidering those choices that you have already eliminated and will thus save you time. It will also help you narrow down your possible answers. 

If you are able to eliminate all but two possible answers, answers such as B and E in the previous example, you may want to guess. Under these conditions, you stand a better chance of raising your score by guessing than by leaving the answer sheet blank. 

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The matrices L , L depend on the choice of the elimination strategy they are not unique. But given a procedure, they can be found. Instead of A, let us write the extended M x (N + M) matrix... 

Each interference type may require a different elimination strategy, the simplest of which is to remove the potential interference before beginning the assay. Removal is commonly done in manual analysis, usually by deproteini2ation, eg, by addition of some denaturing agent such as trichloroacetic acid. 

The control strategy for environmental-impact assessment often focrrses on five alternatives whose prrrpose worrld be the redrrction and/or elimination of polhrtant emissions ... 

The SRK model can also be used as part of a approach for the elimination of errors that have serious consequences proactive for the plant. Once specific errors have been identified, based on the SRK model, interventions such as improved procedures, training or equipment design can be implemented to reduce their likelihood of occurrence to acceptable levels. This strategy will be discussed in more detail in Chapter 4. 

The above strategy was tested [27] with a 3-layer LED consisting of a poly(2,5-thienylene vinylene) (PTV) layer, known to have particularly low oxidation potential [28], followed by a layer of l,4-fcrs-(4 -diphenylaminostyryl)-2,5-di-methoxy-benzene (DASMB) [29] and a layer of 2-(4-biphenyl)-5-(4-tcrt-butyl-pheenyl)-1,3,4-oxadiazol (PBD) dispersed in polystyrene (PS) in a 20 80 ratio. Films of poly-(2,5-thienylene-a-bromoethylcne) were obtained by vapor phase pyrolysis of 2,5-W.v-(bromomethyl)lhiophcne and subsequent vapor deposition of the quinoid monomers onto a cold substrate following a previously published procedure [30]. They were converted to PTV by temperature-induced elimination of HBr. 

The same elimination strategy was used for the synthesis of the natural product (i )-(-)-dysidazirine 15 as is shown in Scheme 10 [23]. The requisite aziri-dine ester was prepared by treatment of sulfimine 19 with the lithium enolate of methyl bromoacetate. This reaction is a Darzens-type condensation leading to czs-M-sulfinylaziridine ester 20. The elimination of sulfenate was accomplished in the same manner as mentioned above (see Scheme 9). The natural product 15 (see Fig. 1) was obtained in 42% yield. Attempts to prepare azirinomycin 14 in a similar fashion all failed [23]. 

Of the four strategies given above, the best condition for obtaining independent data for quality control (QC) are satisfied when INAA and RNAA results are compared, because the use of RNAA dramatically improves the selectivity of signal measurement and eliminates or greafiy reduces the measurement uncertainty sotuces, such as spectral interferences. A variety of radiochemical separations and... 

Trost and coworkers have devised a stereocontrolled 1,3-diene synthesis employing a palladium-catalysed decarboxylative elimination procedure from allylic acetates carrying carboxylic acid functionality ji- to the acetate group (equation 18)48. This decarboxylative elimination strategy has been applied to the synthesis of an insect pheromone, codlemone48a and the ethyl ester of vitamin A carboxylic acid (Table 5)48b. 

Instead of eliminating the bis-condensed byproducts by the above strategy, Shim et al. have found that some bis-condensation products themselves show high fluorescence, if properly designed. A series of bis-condensed DCM derivatives has been synthesized (168-170) (Scheme 3.52) [215]. 

Of the various available techniques, the most widely used are based on the Measurement Test (Mah and Tamhane, 1982). These are the Modified Iterative Measurement Test (MIMT) developed by Serth and Heenan (1986) and the Generalized Likelihood Ratio (GLR) method presented by Narasimhan and Mah (1987). The MIMT method uses a serial elimination strategy to detect and identify only biases in measuring instruments. The GLR method allows us to identify multiple gross errors of any type. It uses a serial compensation strategy. 

Let us consider again the system defined in Example 5.1. From the application of the global statistical test, gross errors were detected among the data set as indicated in Example 7.1. Now the serial elimination strategy will be applied to isolate the source of gross error, that is to identify which set of measurements contains gross error. 

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