Texturization properties, effects

Fig. 3. Effect of using either liquid or supercritical carbon dioxide on the textural properties of titania aerogels calcined at the temperatures shown. (—), dried with Hquid carbon dioxide at 6 MPa and 283 K (-------), dried with supercritical carbon dioxide at 30 MPa and 323 K. Reproduced from Ref. 36.

Modification techniques for activated carhon were used to increase the removal capacity by surface adsorption and to improve the selectivity to volatile organic compounds (VOCs). Modified activated carbons (MACs) were prepared by modifying the purified activated carbon with various acids or bases. The effects of adsorption capacity and modified contents on the textural properties of the MACs were investigated. Furthermore, VOC adsorption and desorption experiments were carried out to determine the relationship between the adsorption capacity and the chemical properties of the adsorbents. High adsorption capacity for the selected VOCs was obtained over lwt%-H3P04/AC (lwt%-PA/AC). As a result, MAC was found to be very effective for VOC removal by adsorption with the potential for repeated use through desorption by simple heat treatment. 

In spite of such positive effects of the presence of ammonia during preparation, the particles sizes remain important on Au/FAU-2, comparable to particles previously described for similar Au/zeolites [1,2]. Noticeably, they are much bigger than expected from the insertion of the Au particles inside the pores. On the contrary, very small gold nanoparticles with a mean diameter of about 2 nm are obtained on the BEA support, that can be due to the textural properties and high external surface area of this support made... 

The effect of the surface area is far from being a simple one. It was shown for titania that when the surface area changes from 110 to 12 m2/g, the average time required for a complete mineralization of organic substrates increased from 40 to 75 and 50 to 75 min for salicylic acid and phenol, respectively [135], These results clearly show that textural properties, particularly the surface area, strongly affect the photoreactivity, although a high-temperature treatment improved their crystallinity [18], Therefore, this phenomenon may be explained only in connection with the catalyst surface dehydroxylation. 

Kumar, K. and Mishra, H. N. (2004). Mango soy fortified set yoghurt Effect of stabilizer addition on physicochemical, sensory and textural properties. Food Chem. 87, 501-507. 

Kaur, A., Singh, N. (2007). Effect of guar gum coating on moisture eontent, oil uptake and textural properties of fried (Freneh fries) potato from different eultivars. J. FoodSci. Technol. -Mysore, 44, 115-117. 

The large surface area of CF makes it an attractive candidate for catalyst support material. Avdeeva and co-workers used CF with different textural properties as supports for Ni to study the methane decomposition reaction. Ni supported on the CF, which was obtained from methane decomposition on a Ni-Cu/Al203 at 898 K, showed the highest yield for secondary carbon (224 gcp/gNi)- Highly porous CF supports were found to be most effective for the secondary generation of CF. 

Effects of Surfactants. Two types of surfactants [sodium stearoyl lactylate (SSL) and calcium stearoyl lactylate (CSL)] at two concentrations (0.2 and 0.4%) were added to soy flours to study the effect of surfactants on the texturization properties of soy flours. An extrusion helper (Tolutein, yeast cell protein) was also included at two concentrations (1 and 2%) in this study because of its behavior similar to a surfactant upon extrusion. 

Materials obtained from the LDH show a reduction in SSA with the temperature as reported in the literature. This reduction can be attributed to the crystallisation of the material [15,17]. However, post-treatment with mineral acid was an increase in the SSA for all temperatures. It is possible to attribute this increase to two combined effects, which can both increase the porosity of the materials, as well as yield more active adsorption sites (i) the elimination of ZnO and (ii) the elimination Zn(II) cations occupying octahedral sites in the spinel oxide structure. Even though the SSA had varied sensibly, the average pore size (APS) remained fairly constant with temperature. Acid treatment increases the APS value for all temperature tested, although the effect was very small (Figure 5b). Comparison of the materials obtained by the different synthesis methods showed that spinel oxides obtained from the LDH presented greater SSA values than those obtained by other methods, principally after the posttreatment with mineral acid. On other hand, the treatment with acid had little influence on the textural properties of the spinel oxides obtained by the other methods. 

Quantitative determinations of the degree of polycondensation in systematic studies have demonstrated that kinetic parameters such as the temperature have little effect on the level of polycondensation in xerogels 40 and 73, and the solvent has a more important effect149,151,152. Variations of 5 to 20% are observed like those presented in Table 3. From these data and those shown in Table 4, it is evident that the degree of polycondensation and the textural properties of the xerogels are generally not related for these precursors. A variation of 5% of the degree of polycondensation is measured while the specific surface area is increased 10 fold. 

These approaches have been reviewed extensively (Jameson, 1990 Ardo, 1997 Fenelon and Guinee, 1997 Fenelon, 2000). Various recommendations for the manufacture of reduced-fat cheeses with improved sensory and textural properties (Mistry et al., 1996 Johnson et al., 1998), (e.g., half-fat Cheddar prepared by homogenization of cream used to standardize the cheese milk) (Nair et al., 2000) the combined effects of increases in milk pasteurization temperature and pH at curd milling, and the use of selected starters and starter culture adjuncts (Guinee et al., 1999 Fenelon et al., 2002) ... 

Watkinson, P.J., Crawford, R.A., Dodds, C.C. 2002. Effect of moisture on instrumentally measured textured properties of model cheese. Aust. J. Dairy Technol. 57, 153 (1 page). 

The tailoring of protease preparations to rapidly produce hard cheeses in a cost effective manner and with good flavor and textural properties, is progressing rapidly. In the next few years several new and innovatively tailored enzyme preparations will be available for accelerating the production of hard cheeses. 

Figure 8-45 The Three Regions of the Sorption Isotherm Related to the Textural Properties of Food Systems. Source Reprinted with permission from M.C. Bourne, Effects of Water Activity on Textural Properties of Food, in Water Activity Theory and Applications to Food, L.B. Rockland and L.R. Beuchat, eds., p. 76,1987, by courtesy of Marcel Dekker, Inc.

Bourne, M.C. 1987. Effects of water activity on textural properties of food. In Water activity Theory and applications to food, ed. L.B. Rockland and L.R. Beuchat. New York Marcel Dekker. 

Pietrasik, Z., and Jarmoluk, A. (2003). Effect of sodium caseinate and K-carrageenan on binding and textural properties of pork muscle gels enhanced by microbial transglutaminase aAAitioa. Food Res. Int. 36, 285-294. 

In this work, a comparative study of the textural properties developed by the intercalation and pillaring of a saponite with various aluminium oligomers is presented. The adsorption models above summarized have been applied to the nitrogen adsorption at 77 K results in order to evaluate the effect of the oligomer nature and the calcination temperature on the MPSD of the prepared solids. 

The effect of the pH ranging between 11.9-14.0 in the sol-gel synthesis of silica-aluminas MSA and ERS-8 has been studied. A progressive variation from white opalescent to transparent gels was observed. After drying and calcination, the gel textural properties were compared by N2 adsorption/desorption. 

Another important parameter that has to be deeply considered is the pH. It is well known the role of pH on silica chemistry it affects dissolution and polymerization rate, gel or precipitate formation and the textural properties of the final silica (11). Also for surfactant micelle or cluster templated syntheses of silica-aluminas, the effect of pH on porosity remains relevant and it is strongly influenced by the kind of material and by the synthesis route selected for its preparation. 

The variation of TPAOH amount during the synthesis of silica-aluminas has two macroscopic effects the change of the pH and of the relative amount of TPAOH to silico-aluminate oligomers. The textural properties of the final silica-aluminas may result from the different sequence of hydrolysis and condensation reactions (and the reverse reactions esterification and alcoholic or hydrolytic depolymerization) of the Si and A1 alkoxides. Indeed an increase in TPAOH content and therefore of the pH corresponds to an increase of OH" availability that can favor the hydrolysis and depolymerization reactions, giving rise to different gelation rate and to different network formation. 

The main objective of this work is to analyse the effect of chemical dealumination by ammonium hexafluorosilicate treatment on the textural properties of Y zeolite. 

Phosphorus also modifies the textural properties of the M0S2 slabs (depending on the phosphorus content). It tends to increase the number of stacked M0S2 layers. These modifications might lead to the following positive effects on the catalyst ... 

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