Pore lining treatment

F ie 14.1 Schematic representation of the different types of surface treatment of concrete (o) organic coating, (fc) pore-lining treatments, (c) pore-blocking treatments, (d) thick cementitious coating, shotcrete or rendering, (6)... 

Retinoids, which are highly effective in the treatment of acne, stimulate epithelial cell turnover and aid in unclogging blocked pores. Retinoids also exhibit anti-inflammatory properties through the inhibition of neutrophil and monocyte chemotaxis.8 Because of these comedolytic and antiinflammatory effects, topical retinoids are recommended as first-line treatment for mild to moderate comedonal and inflammatory acne.3 While success is seen with monotherapy, using a retinoid in combination with benzoyl peroxide or topical antibacterials is also an appropriate and effective therapeutic treatment option.3 Tretinoin, adapalene, and tazarotene are topical retinoids available for use in the treatment of acne. Table 62-2 describes the strengths and formulations of these agents. 

Benzoyl peroxide is easy to use and recommended as first-line therapy in the treatment of mild to moderate noninflammatory acne. Benzoyl peroxide has a comedolytic effect that increases the rate of epithelial cell turnover and helps to unclog blocked pores. It also has antibacterial activity against P. acnes, which appears to be the main reason for the effectiveness of this product.13... 

The greatest care in. manipulation, and the most scientific methods in the treatment of wine, have been tried in France, and the result has been the production of the finest winos in the world. The removal of the wine from the vat to the cask is there as carefully regarded as the work of fermentation. The casks are all made ready at the same time as the vats. If the wood of which they are made is new, they will not fail to communicate an astringeuey and bitterness to the wine. To prevent this, the casks are repeatedly washed with cold water, and then with hot, in which peach leaves and salt are infused. They are repeatedly shaken while the fiald is hot, and then are left so that the wood may absorb them, and they may penetrate into the pores of the timber. The casks are now emptied, and boiling hot must, to the extent of two or three quarts, is introduced. The bungs are put in, the casks shaken, and then left to cool. Some use only hot wine in place of the above substances. If the casks ore old, they scrape off the tartar that lines the staves, and wash them vrtth hot water and must, or wine. If they have contracted an ill smell, or show the least mark of decay, they are burned at once, because, in... 

Figure 6. Sediment pore-water profiles for various IAG-related parameters in treatment basin (T, solid line) and reference basin (R, dashed line), 5-m sites,...

Chemical vapor deposition of silanes, along with a subsequent calcination using steam, can be utilized to deposit silica (Si(>2) inside the pore system. By variation oF the temperature, the partial pressure of the silane and the duration of the treatment, location and amount of the deposited material can be controlled [104]. When, for example, tetraethoxy- or tetrame-thoxysilane are used as reacting agents on a mordenite, ZSM-5, or /1-zeolite, then a controlled deactivation of only the external cristallite surface is possible [23, 44]. This is because these are rather bulky molecules which are not able to diffuse into the pore system of the crystallite. Alternatively, an irreversible adsorption of bulky bases may serve to destroy the undesired external acidity. Suitable basic compounds are 4-methylquino-line for ZSM-5 [2] and tributylphosphite for mordenites [71]. 

We prepared two carbons by pyrolysis of saccharose followed by heat treatment at two different temperatures 400 C (CS400) and 1000"C (CSIOOO). We performed X-ray diffraction and SAXS on each of these porous materials and obtained the structure factors, S q), following the procedure described by Franklin [14]. The resulting S(q) s are shown in Figure 1 (bold line). We performed Hg porosimetry to obtain the density of both carbons, accounting for the volume occupied by C atoms, closed pores and smaller open pores. We also measured the H/C and the O/C ratios by combustion experiments. The results are summarized in Table 1. 

Jia/Noble and coworkers [87,88] reported the successful synthesis of silicalite membranes on y-alumina composite supports using an interesting modification of the in situ crystallisation method. The support consisted of a short a-alumina tube coated on the inside with a 5 pm thick y-alumina film with an average pore diameter of 5 nm, commercially available from US Filter. The precursor solution was put into the support tube after plugging both ends with teflon and the filled tube was then placed in a teflon-lined autoclave. Hydrothermal treatment was carried out at 180°C for 12 h. After removal from the autoclave and washing the formed zeolite layer with water, the procedure was repeated with the tube inverted from its previous orientation to obtain a uniform coating. As reported by Vroon et al. [82,84,98], Jia/Noble [88] also concluded that at least two synthesis steps are necessary to obtain defect-free membranes. 

Fig. 1 reports the XRD patterns of materials obtained at 60°C for different treatment durations. At this tenperature, onfy one peak located at 13.0, 11.6 and 16.4 nm for heating times of 2 (Fig.lb), 3 (Fig.lc) and 11 days (Fig.ld) respectively, is detected. The presence of only one reflection line indicates that the compounds belong to the MSU or DWM femily. The structure of these moleeular sieves consists of regularly sized wormhole-like channels. The single broad peak arises from the average pore-to-pore separation in the disordered... 

In the present studies, a-alumina, a non porous alumina, has been used as a standard. The surface area of this sample is 9 m /g and monolayer volume is 2 cc/g.It can be concluded from the Figure 2 that v-a plot for AD-101 is almost a straight line passing origin. Treatment of AD-101 with alkali shows an upward deviation from straight line which shows an increase in mesopore. However, the upward deviation is minimised in the acid treated sample which is in agreement with the pore size distribution for these samples. ... 

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