Constant mass

A constant-mass-difference scan. Source ions (m, f,. .., fj) are passed successively by Q1 into Q2, where collisionally induced dissociation occurs. Q3 is set to pass only those ions produced in Q2 that have a predetermined mass difference (Am) between the ions passed by Ql. In this example, they are m, - f, (= Am) and f, - fj (= Am), so, although all ions pass into Q2, only f, f, have a mass difference (Am) equal to that selected for Q3. 

This leads to rate equations with constant mass transfer coefficients, whereas the effect of net transport through the film is reflected separately in thej/gj and Y factors. For unidirectional mass transfer through a stagnant gas the rate equation becomes... 

When determining bulk density, a distinction should be made between loose bulk density and tap density, eg, ASTM B527-81. The latter is a measure of the influence of settling on filler volume at constant mass. 

Volatiles such as residual methanol, methyl acetate, and water are determined as the loss in mass when the polymer is dried at 105 2° C until constant mass is attained. Higher drying temperatures may cause decomposition and related additional weight loss. 

All applications are for closed systems with constant mass. If a process is reversible and only p-V work is done, the first law and differentials can be expressed as follows. 

When applied to closed (constant-mass) systems for which the only form of energy that changes is the internal energy, the first law of thermodynamics is expressed mathematically as... 

E. Laminar, fully developed parabolic velocity profile, constant mass flux at wall... 

For example, consider an open tubular column with the dimensions previously defined, operated at constant mass flow rate of helium (which is normal for temperature programming purposes), then, from Poiseuille s equation, after time (t),... 

Flow Rate (constant mass flow rate) 5 ml/min. (0.08333ml/sec)... 

Evaluation of the consistency of relevant experimental results. Stoichiometric constant. Mass and energy balances. 

The released ammonia forms a pool of refrigerated liquid which evaporates by heat transfer from the soil. A constant mass value was assumed for the evaporation rate and a heavier-than-air gas dispersion model was used. 

Epsom salts are hydrates of magnesium sulfate. The formula for Epsom salts is MgS04 - 7H20. A 7.834-g sample is heated until a constant mass is obtained indicating that all foe water has been evaporated off. What is foe mass of foe anhydrous magnesium sulfate What percentage of foe hydrate is water ... 

Figure 8 shows that increasing the heat flux at constant mass velocity causes the peak in wall temperature to increase and to move towards lower enthalpy or steam quality values. The increase in peak temperature is thus due not only to a higher heat flux, which demands a higher temperature difference across the vapor film at the wall, but to a lower flow velocity in the tube as the peaks move into regions of reduced quality. The latter effect of lower flow velocity is probably the dominant factor in giving fast burn-out its characteristically rapid and often destructive temperature rise, for, as stated earlier, fast burn-out is usually observed at conditions of subcooled or low quality boiling. 

Km Michaelis-Menten constant mass transport coefficient... 

Darbyshire AG, Mullin T (1995) Transition to turbulence in constant-mass-flux pipe flow. J Fluid Mech 289 83-114... 

Appropriate electroanalytical procedures to verify the one or other case have been given in the references of this section. The main techniques are cyclic voltammetry, chronoamperometry, chronocoulometry, and rotating disk voltammetry. The last one appears to be best suited since constant mass transport in the film is a very important feature as outlined aixive Table 2 gives examples for... 

The most important characteristic of an ideal batch reactor is that the contents are perfectly mixed. Corresponding to this assumption, the component balances are ordinary differential equations. The reactor operates at constant mass between filling and discharge steps that are assumed to be fast compared with reaction half-lives and the batch reaction times. Chapter 1 made the further assumption of constant mass density, so that the working volume of the reactor was constant, but Chapter 2 relaxes this assumption. 

Equation (8.64) allows the shape of the velocity profile to be calculated (e.g., substitute ytr = constant and see what happens), but the magnitude of the velocity depends on the yet unknown value for dPjdz. As is often the case in hydrodynamic calculations, pressure drops are determined through the use of a continuity equation. Here, the continuity equation takes the form of a constant mass flow rate down the tube ... 

Constant mass flow in each phase i.e., negligible net mass transfer... 

The acetyl component balance for constant mass conditions is given by... 

BATCH DECOMPOSITION OF ACETYLATED ACETIC ACID CONSTANT MASS MODEL... 

The water content of a sample is a basic datum for calculating the value per gram of dry matter. Water content is expressed as the ratio of the mass of water present in the sample to the mass of the sample after it has been oven dried at 105 °C to a constant mass. Alternatively, the ratio of the mass of water present in the sample to the mass of the sample before oven drying is used. It is important to specify which is being used. 

Figure 9. A schematic and ideal model showing how the residence time of the magma in a steady-state reservoir of constant mass M, replenished with an influx O of magma and thoroughly mixed, can be calculated from disequilibrium data, in the simplifying case where crystal fractionation is neglected (Pyle 1992). The mass balance equation describing the evolution through time of the concentration [N2] (number of atoms of the daughter nuclide per unit mass of magma) in the reservoir is ...

We assume that a constant mass fraction fr remains in the mantle wedge after melt extraction. As in Section A2 of the Appendix, the ratio of slab mass to wedge mass is assumed to be equal to 1 but more complex models are also possible. The bulk composition of the mantle wedge after melt extraction is calculated with the following equation after each extraction increment ... 

Quartz fine aggregates and normal Portland cement were used to prepare mortar at a w/c of 0.6. Mortar was cast into 30-mm diameter by 30-mm length cylinders and cured for 3 days. At the end of the curing period the specimens were oven dried at 105 °C until a constant mass was reached. Epoxy was then applied to the curved surface and the specimen was placed such that 1-2 mm of its height was immersed in a 20% NaCl solution. 

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