Surface enlargement

Figure 4-425. Metal surface enlarged, showing schematic arrangement of local action cells. (From Ref. [195].)...

The uranium uptake rate increases with decreasing granular size because of the specific surface enlargement. Yet, after ten days both curves show a distinct flattening. After this time, hydrous titanium oxide granules of 0.6 mm diameter attain a uranium loading of 100 ppm. The demonstrated uptake rates seem to be realistic for mechanically rather stable hydrous titanium oxide granules. 

When the total device thickness is to remain in the micrometre regime, and a sizeable surface enlargement is to be obtained, the feature size of the substrate structure needs to be in the micrometre region or below. One is hence looking for substrate structures that provide a micro- or nano-scale pattern. For photovoltaic applications this pattern, and the necessary manufacturing processes, must be extendable over very large areas. New deposition techniques which provide... 

Fig. 8.3 Physical processes associated with surface enlargement during boundary friction, reproduced with permission from [21]...

Presence of surfactant at the interface will also directly affect deformation. The surfactant allows formation of a /-gradient. This would affect the deformation mode of a drop, which has indeed been observed. Moreover, enlarging the interfacial area causes y to increase, as mentioned. This implies that the interfacial free energy increase includes two terms y dA + A dy. The first term is due to the deformation of the drop being counteracted by its Laplace pressure the second is due to surface enlargement being counteracted by the surface dilational modulus ESD. Making use of Eq. (10.20) for we obtain... 

The initial values of the polarizing resistance of the electrode in contact with modified PE films are 1.5-2 times higher than those of unmodified ones and are in agreement with the hydrophobic properties of the Cl. Hydrophoby rises through the series MO, SIM, Ukramin, AKOR. The kinetic curves of Rp —tr show two characteristic sections. The slope in the first second (initial) is dependent upon the PI and Cl content in the film material. The inclination of the second section remains constant for all samples. Consequently [118], Rp attenuation on the first section is the result of the contact area of the electrolyte and metal surface enlarging with time as the adsorbed Cl molecules are removed from it. The variation velocity of Rp in the second section is... 

Based on the experimental results as well as Hterature data, it can be concluded that the adsorption of Bronsted acid-doped polyaniHne on Ba, Mg, Ge, Sn, and A1 oxide surfaces enlarges the pH range in which the conducting polymer remains doped, that is, enlarges its pH range of maximum conductivity. Furthermore, the oxide-polymer samples exhibit higher processability, when compared with the polymer. Obviously, such facts could have useful influences on the possible technological applications of polyaniline. 

With orientation, the thickness is reduced and the surface enlarged. If film is longitudinally stretched in the elastic state, the thickness and the width are reduced in the same ratio. If lateral contraction is prevented, stretching reduces the thickness only. 

Fig. 19. Pitch-based carbon fiber fracture surface enlarged view.

Fig. 220. Unspecific endothelial surface enlargement after intermittent hypoxia. Hippocampus of a female Wistar rat (No. 5/5) treated for 4 consecutive days with intraperitoneal injection of 1.5 ml Ringer s solufion per kg body weighf x day. 30 min after each medication the animal was exposed to an atmosphere containing only 5 % oxygen for 30 min. Half an hour after the last exposure, under pentobarbital anaesthesia (30 mg/kg), the animal was perfused from fhe abdominal aorta with 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.4). Posffixafion wifh 1 % osmium tetroxide in sodium cacodylafe buffer. Embedded in Epon 812 and sec-fioned at 50 nm. Lead citrate and uranyl acetate. Eihn 242-39...

A reason might be the surface enlargement due to plasma etching. The present effect was confirmed by Feijen s work, who likewise observed an increase in fibrinogen adsorption at Ar plasma treated polyethylene surfaces... 

E is Young s modulus and v Poisson s ratio of the considered material. A quantitative form can now be derived for the criterion of crack formation which was described only qualitatively above. Let us consider that the crack grows by a small length Ax. The energy needed for surface enlargement per unit length of crack width can be expressed as ... 

Micro enzyme reactor for continuous glucose monitoring pSi is fabricated on high aspect ratio Si microstmctures of the reactor by electrochemical etch Surface enlarging effect, 100-fold increase in enzyme activity Drott et al. 1998... 

Fig. 1 Example of an early porous silieon enzyme microreactor with surface-enlarging parallel microchannels, anisotropically etched in silicon followed by a porous silicon anodization step...

The apparently higher gam in EA, 3 7, than m surface enlargement, 3 0, is partly an effect of the choice of approximation for Vmax Another estimation yields an EA gam of 3 3 Also, the area at the entrance and exit holes are believed not to contribute as much to the EA as the lamella area due to the difference m flow distribution If only the lamella area gam is considered, the factor is 3 2 Furthermore, the yield m the enzyme immobilisation procedure may differ somewhat from one occasion to another These factors may explain the deviation... 

Surface enlargement All metabolically active structures strive for this and it is achieved here by the arrangement of the membrane systems as thylacoids. 

---