Swelling apparent

Nitrating cellulose with pure HNO is the simplest method of obtaining CN. In practice, nitration does not occur with acid concentrations below 75%. At acid concentrations <75%, an unstable compound (so called Knecht compound) is formed which has been described as a molecular complex or an oxonium salt of the nitric acid (72). HNO concentrations of 75—85% yield CN with 5—8% N, which dissolve in excess acid. CN with % N of 8—10% are formed at acid concentrations of 85—89%. Above 89%, a heterogeneous nitration occurs without apparent swelling of the cellulose fibers. CN with 13.3% N can be obtained with 100% HNO. Addition of inorganic salts to 100% HNO can raise the % N to 13.9. 

In the case of crystalline polymers better results are obtained using an amorphous density which can be extrapolated from data above the melting point, or from other sources. In the case of polyethylene the apparent amorphous density is in the range 0.84-0.86 at 25°C. This gives a calculated value of about 8.1 for the solubility parameter which is still slightly higher than observed values obtained by swelling experiments. 

Together with this solvent effect, another effect, called phase soaking, occurs in the retention gap technique if a large volume of solvent vapour has saturated the carrier gas, the properties of the stationary phase can be altered by swelling (thicker apparent film), a change in the viscosity or changed polarity. The consequence is that the column shows an increased retention power, which can be used to better retain the most volatile components. 

On occasion, gelatinous material is apparent in time it usually dissolves or swells greatly. 

Figure 4. Schematic description of the swelling process. The molecules of the swelling liquid start to penetrate inside the polymer framework from its surface (a) and to solvate the polymer chains. The polymer chain start to stretch out and to move away from one another the apparent volume of the polymer increases and the first nanopores are formed (b). Swelling stops when increasing elastic forces set up by the unfolding of the polymer chains counterbalance the forces which drive the molecules of the swelling agent into the polymer framework (c).

The most frequent adverse effects are local reactions at the injection site (pain, tenderness, erythema, swelling, and pruritus), fevers (greater than 37.5°C or 99.5°F), headaches, dizziness, and irritability. Anaphylaxis and hypersensitivity reactions have been reported rarely and occur within a few hours after vaccine administration. In rare instances, a serum sickness-like apparent hypersensitivity syndrome (arthralgia, urticaria, ecchymoses, erythema multiforme, and erythema nodosum) has been... 

Two other features are notable in Table III. The swelling values for the compression molded samples (CM) run consistently less than those for the solvent-cast films. Apparently there is more "entrapment" of the amorphous portions within the crystallites during and after the molding. Secondly, the degradation experienced by the polymer hydrogenated at 69°C. (see Table II) instead of 52°C. is clearly demonstrated by the higher swelling value. 

A crucial requirement in future investigations is that macroscopic measurements of stress and swelling be performed on the same materials used for small angle neutron scattering. A sensible program for research is apparent. The work remains to be done. 

There are apparently two sources of this effect. The molar volume of water changes relatively little as a result of the presence of a small quantity of dissolved octanol, however the quantity of dissolved water in the octanol is considerable, causing a reduction in molar volume of the octanol phase. The result is that even if activity coefficients are unaffected, log S0/Sw will be about 0.1 units less than that of log KoW. Effectively, the octanol phase swells as a result of the presence of water, and the concentration is reduced. In addition, when log KqW exceeds 4.0 there is an apparent effect on the activity coefficients which causes log (SQ/SW) to increase. This increase can amount to about one log unit when log Kow is about 8. A relatively simple correlation based on the analysis by Beyer et al. (2002) (but differing from their correlation) is that... 

On examination, joint swelling may be visible or may be apparent only by palpation. The tissue feels soft and spongy and may appear erythematous and warm, especially early in the course of the disease. Chronic joint deformities commonly involve subluxations of the wrists, metacarpophalangeal joints, and proximal interphalangeal joints (swan-neck deformity, boutonniere deformity, ulnar deviation). 

Pain and inflammation may accompany infection and are sometimes manifested by swelling, erythema, tenderness, and purulent drainage. Unfortunately, these signs may be apparent only if the infection is superficial or in a bone or joint. 

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