Mechanical disintegration

OCP of magnesium is 0.6 to 1.1 V more positive than the thermodynamic value. The negative difference effect that is seen in anodic magnesium dissolution (see Section 16.2) can, in part, be attributed to partial mechanical disintegration of the passivating layer during magnesium dissolution. 

The pressure can sharply facilitate the penetration of the corrosive into the depth of the eye. By a physical phenomenon, the pressure entails a mechanical disintegration of the tissues. This will aggravate all the lesions. 

Our experimental work started from the following original cellulose samples (a) acetate-grade, bleached cotton linters, DP 1800 (b) hot, refined, spruce, sulphite-dissolving pulp, machine dried, ca. 93% a-cellulose, DP — 750 (c) never-dried, normal, rayon-grade, beech sulphite pulp, ca. 90% a-cellulose, DP = 825 (d) commercial cellulose powders obtained by hydrolytic degradation and/or mechanical disintegration of cotton linters or spruce sulphite pulp. 

It seemed reasonable to supplement our results obtained with low-DP linters cellulose powders by some experiments with high-DP cotton linters, given analogous pretreatments in the original state and after mechanical disintegration. 

Acid hydrolysis of these samples led to the results to be expected, i.e., a lowering of LODP and residue value by NH3 pretreatment and mercerization as well as by mechanical disintegration prior to the hydrolytic treatment (Table XII). With regard to residue value, an NH3 pretreatment again proved to be more efficient in enhancing accessibility than a mercerization, while the rate constant of chain-length degradation was increased somewhat more by mercerization. 

With the samples at first mechanically disintegrated, all the statements regarding the influence of an NH3 and an NaOH pretreatment were confirmed (Table XII). In any case, the previous mechanical disintegration decreased the rate of enzymatic attack as compared with the appropriate nondisintegrated samples. Probably some homification and/or change in pore structure occurs during mechanical disintegration in the dry state. 

Another kind of nanocellulose can be prepared from the nearly inexhaustible source of feedstock wood using controlled mechanical disintegration steps to produce the favored product properties. 

In contrast to BC, cellulose from wood is composed of fibers that are about one hundred times thicker [17] (Fig. 4a). Because of the complex and expensive cultivation of BC (sophisticated medium and long cultivation time), it is also a challenge to produce nano-fibrillated celluloses from wood. The substructures of wood are only accessible by chemical treatment [16] and mechanical disintegration procedures. 

Apart from its thermochemical and catalytic activities, it. seems very probable that pyrites can assist in the oxidation of coal in a purely mechanical manner as well, inasmuch as it tends to swell on oxidation and thus to increase the mechanical disintegration of the coal, thereby exposing larger surfaces to aerial attack.4... 

Capacity fading — Loss of faradaic - capacity of the active mass in a -> secondary battery, i.e., reduction of the amount of electric charge which can be stored and retrieved. Numerous causes depending on the type of secondary battery maybe effective mechanical disintegration, loss of electrical contact between particles constituting the active mass, changes in chemical composition, and partial dissolution are only a few. 

In natural cellulose, the microcrystals are packed tightly in the fiber direction in a compact structure resembling bundles of wooden match sticks placed side by side. Unhinging the interconnecting chains by acid treatment does not destroy this structure. However, the unhinged crystals are now free to be dispersed by mechanical disintegration.. . . We immediately set out to explore this new avenue, developing uses for colloidal dispersions of microcrystalline celluloses, known commercially as Avicel. 

Chewable tablets are designed to be mechanically disintegrated in the mouth. Potential advantages of chewable tablets are mainly concerning patient convenience and acceptance, although enhanced bioavailability is also claimed. This can be due... 

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