Reversible sequential design

Reverse-flow-cleaned filters are similar to the shaker-cleaned design, except the shaker mechanism is eliminated. As with shaker-cleaned filters, compartments are taken off-line sequentially for cleaning. The primary use of reverse-flow cleaning is in units using fiberglass-fabric bags at temperatures above 150°C (300°F). 

Pandey, G., Hajra, S., Ghorai, M.K., and Kumar, K.R. (1997) Designing photosystems for harvesting photons into electrons by sequential electron-transfer processes reversing the reactivity profiles of a,p-unsaturated ketones as carbon radical precursor by one electron reductive p-activation. Journal of the American Chemical Society, 119, 8777-8787. 

Once the right set of parameters has been identified, computer-aided optimization using modified sequential simplex or central composite design methods can be applied to further hne-tune the separation under investigation, as has been published for the optimization of reverse-phase HPLC [17-20] and chiral separations [21-23]. 

Figure 4.67. Manifolds designed for speciation analysis of Cr(VI) and Cr(III) by reversed FI A, both species being determined spectrophotometrically by a single detector, (a) Asynchronous merging zones mode for simultaneous determination of both species, (b) Sequential method for this speciation by use of a selecting valve for determination of Cr(VI) (channel 1) or overall chromium (channel 2). (From Ref. 968, by permission of Springer Verlag.)...

The sequence of the design can be reversed, and the quantitative study may be carried out first and carry the dominant priority. This strategy is known as the sequential explanatory design as shown in Figure 3. 

Even so, I designed my study to minimize this potential risk Unless indicated otherwise, my precautions follow Podsakoff et al. (2003] The questionnaire was checked by the person responsible for disseminating the survey in each Arm for its unequivocality. In the introduction, anonymity was assured to all participants. I posed specific questions about product use and behavior in the firm, rather than about abstract attitudes (Cote and Buckley 1987], Questions relating to predictor and criterion variables were intermingled rather than sequential and used different types of scales (Likert scales, ordinal scales, semantic differentials]. If possible, I excluded reverse coded items as they may favor common method bias (DiStefano and Motl 2006]. 

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