An introduction to six sigma and pocess improvement: pengantar six sigma

Bai

Capillary condensation and adsorption in cylindrical and slit-like pores

The nature of adsorption of simple fluids confined in model pores is investigated by means of a density functional approach. For temperatures T corresponding to a partial wetting situation a first-order phase transition (capillary condensation) from dilute ‘gas’ to dense ‘liquid’ occurs at relative pressuresp/psrttclose to those predicted by the macroscopic Kelvin equation, even for radii R, or wall separations H as small as 10 molecular diameters. In a complete wetting situation, where thick films develop, the Kelvin equation is, in general, not accurate. At fixed T the adsorption T,(p) exhibits a loop; Tmjumps discontinuously at the first-order transition, but the accompanying metastable portions of the loop could produce hysteresis similar to that observed in adsorption measurements on mesoporous solids. Metastable thick films persist to larger p/psatin slits than in cylinders and this has repercussions for the shape of hysteresis loops. For a given pore size the loop in Tmshrinks with increasing T and disappears at a capillary critical temperature T r p ( TEaPcondensation no longer occurs and hysteresis of Tm will not be observed. Such behaviour is found in experiments. A prewetting (thick-thin film) transition can occur for confined fluids. The transition is shifted to a smaller value of p/psat than that appropriate to prewetting at a single planar wall. Whereas the magnitude of the shift is very small for slits, it is substantial for cylinders and this leads to the possibility of finding a triple point, where ‘liquid’ and thick and thin films coexist, in cylindrical pores whose radii may not be too large for investigation by experiment or computer simulation. Adsorption of super- critical fluids ( T > T,, the bulk critical temperature) in cylinders is mentioned briefly

Web strategy in the digital economy: An Organizational perspective

[[abstract]]The Internet, for many businesses, has become as invaluable as human resources, equipment, and distribution channels. Continued current use and implementation of new Internet tools will further enhance business and continue to improve the business model and the return on investment. A good Web strategy works with an organizations' business strategy to design and implement a Website that meets the goals of its business strategy. After building a Web presence, the thought process is on continuous improvement of the business model and its value chain. The Web strategy, as explored in this chapter, includes enhancement of the online community, personalization, content, ecommerce, extranets, and intranets.[[notice]]補正完