Molecular weights keeping constant

In Eq. (PP), N is the gas concentration (molecules cm 3), um is the average molecular speed in the gas phase, R is the gas constant (J K 1 mol ), T the temperature (K), and M is the molecular weight (kg) of the gas. The normalized rates, i.e., divided by the rate of gas-surface collisions in Eq. (PP), will be referred to as conductances, T, for reasons that will become apparent shortly. However, the reader should keep in mind that these conductances just reflect the speeds of the individual processes. 

It is immediately noticed that the tp s do not depend on the number of subchains chosen [cf. Ferry (96)). In the first place the friction factor f of the single bead must be inversely proportional to the number of beads chosen per unit of chain length, in order to keep the frictional resistance per unit of chain length constant. This means that ffV must be proportional to the molecular weight. In the second place, b2N is equal to the mean square end-to-end distance of the total chain in a solution at rest. Also this value must be proportional to the molecular weight and independent of the number of subchains chosen. This is in agreement with Section 2.6.3. According to eqs. (3.37) and (3.50) one obtains for the contribution of the macro-molecules to the viscosity of the solution ... 

Acetylated hematoporphyrin (1 part by weight) is dissolved in 0.1 N sodium hydroxide (50 parts by volume) and stirred for 1 h at room temperature. After the stir period the solution is adjusted to pH 9.4 to 9.6 with 1 N hydrochloric acid. It is filtered through a 5 pm filter and then concentrated to (12.5 parts) of its original volume in an ultrafilter with 10,000 molecular weight cut off membranes. The solution is then purified via diafiltration maintaining constant volume with 120 volumes of water and keeping the pH at 9.4 to 9.6 with 0.1 N sodium hydroxide. This is also done at room temperature. After the purification, the solution is removed from the ultrafilter, diluted to 3/8 (18.8 parts) of its original volume and pH adjusted to 7.5 to 7.7 with 1 N hydrochloric acid. The solution is then stored at 4°C for 14 to 21 days. After... 

At times t >Teq, the wriggling motion results merely in a fluctuation around the primitive path, so the ch moves coherently in a one-dimension diffusion process, keeping its arc length constant. The macroscopic diffusion coefficient of a reptating chain scales with chain length (molecular weight) as ... 

Table 4 summarizes the different conditions and compositions that were achieved in a blending study of narrow molecular weight PB with inly = 3 kg/mole incorporated into the KRO-1 particles in PS. As the table indicates in the blending, the total volume fraction of KRO-1 Resin and PB3000 was kept constant to maintain a constant volume fraction of composite particles at 21.7%. In addition, pain was taken to keep the average composite particle size also roughly constant by the use... 

With the R3A1— H20 system polymer molecular weight and crystallinity depend strongly on temperature, keeping the other parameters constant. Increasing the temperature from —78 °C to 0 °C leads to a decrease in the molecular weight from 5.6 105 to 104 and in the degree of crystallinity from 30 % to 0. 

It is helpful to use a standard form when calculating a norm by hand. This may be done by laying out the oxides (with their molecular weights and therefore the molecular proportions) as columns along the top of the page and the more common normative minerals as rows along the left-hand margin. The boxes of the fable are filled as the calculation is made and can be used to keep a check on when an element is totally used up. Constants used in the CIPW norm calculation are listed below. 

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