'Hierarchy' is a property which can be attributed to a manifold of different immaterial systems, such as ideas, items and organisations or material ones like biological systems within living organisms or artificial, man-made constructions. The property 'hierarchy' is mainly characterised by a certain ordering of individual elements relative to each other, often in combination with a certain degree of branching.Especially mass-flow related systems in the natural environment feature special hierarchically branched patterns. This review is a survey into the world of hierarchical systems with special focus on hierarchically porous zeolite materials. A classification of hierarchical porosity is proposed based on the flow distribution pattern within the respective pore systems. In addition, this review might serve as a toolbox providing several synthetic and post-synthetic strategies to prepare zeolitic or zeolite containing material with tailored hierarchical porosity. Very often, such strategies with their underlying principles were developed for improving the performance of the final materials in different technical applications like adsorptive or catalytic processes. In the present review, besides on the hierarchically porous allzeolite material, special focus is laid on the preparation of zeolitic composite materials with hierarchical porosity capable to face the demands of industrial application.

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1 ri the course of screening hundreds of plant samples for steroidal sapogenins, it became imperative to find a procedure that would rapidly detect and estimate these compounds. 1 literature search indicated that a rapid and specific procedure was not available. It was found that a negative hemolytic test on alcoholic plant extracts was definite proof of the absence of steroidal saponins. Samples giving positive hemolytic tests were acid hydrolyzed and acetylated, yielding a crude residue. Steroidal sapogenins coiild he detected, and the quantity present estimated from the highly specific infrared absorption spectra of all sapogenins. By this procedure, a large number of plant samples (40 to 50 by tw-o workers in a 40-hour week) can be screened rapidly for steroidal sapogenins. Consequently, the rcarch for these valuable precursors for cortisone and sex hormones has been conducted at a great]?iricrcased rate.S RECEKT years steroidal sapogenins have attracted con-

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A series of carbide-derived carbons (CDC) have been prepared starting from TiC and using different chlorine treatment temperatures (500ºC-1200ºC). Contrary to N 2 adsorption measurements at -196ºC, CO 2 adsorption measurements at room temperature and high pressure (up to 1 MPa) together with immersion calorimetry measurements into dichloromethane suggest that the synthesized CDC exhibit a similar porous structure, in terms of narrow pore volume, independently of the temperature of the reactive extraction treatment used (samples synthesized below 1000ºC). Apparently, these carbide-derived carbons exhibit narrow constrictions were CO 2 adsorption under standard conditions (0ºC and atmospheric pressure) is kinetically restricted. The same accounts for a slightly larger molecule as N 2 at a lower adsorption temperature (-196ºC), i.e. textural parameters obtained from N 2 adsorption measurements on CDC 2 must be underestimated. Furthermore, here we show experimentally that nitrogen exhibits an unusual behavior, poor affinity, on these carbide-derived carbons. CH 4 with a slightly larger diameter (0.39 nm) is able to partially access the inner porous structure whereas N 2 , with a slightly smaller diameter (0.36 nm), does not. Consequently, these CDC can be envisaged as excellent sorbent for selective CO 2 capture in flue-gas streams.