Mass generation

For theJth. component, my = m iDy is the component mass flow rate in stream i is the mass fraction of component j in stream i and q is the net reaction rate (mass generation minus consumption) per unit volume V that contains mass M. If it is inconvenient to measure mass flow rates, the product of density and volumetric flow rate is used instead. 

Figure 6.5. Fraction of pool and aerosol mass generated after loss of containment of small vessels containing CFG 114, depending on degree of superheat and degree of filling (Schmidli etal. 1990).

Net internal mass generation due to chemical reactions within the system... 

Net rate of internal mass generation by chemical reactions... 

Assuming that the distribution of masses inside the volume V is given, this vector function g p) depends only on the coordinates of the observation point p, and by definition it is a field. It is appropriate to treat the masses in the volume V as sources of the field g p). In other words, these masses generate the field at any point of the space, and this field may be supposed to exist whether a mass is present or absent at this point. When we place an elementary mass at some point p, it becomes subject to a force equal to... 

This field is the dominant part of the total field, since the irregular part of the masses generates not more than several hundreds of milliGalls, which constitutes less than 0.1% of the resultant field. 

Figure 2.4. Peptide fingerprinting by MALDI-TOF mass Spectrometry. Proteins are extracted and separated on by 2D gel electrophoresis. A spot of interest is excised from the gel, digested with trypsin, and ionized by MALDI. The precise mass of proteolytic fragments is determined by time-of- flight mass spectrometry. The identity of the protein is determined by comparing the peptide masses with a list of peptide masses generated by a simulated digestion of all of the open reading frames of the organism.

In the real world the stress tensor never vanishes and so requires a nonvanishing curvature tensor under all circumstances. Alternatively, the concept of mass is strictly undefined in flat Minkowski space-time. Any mass point in Minkowski space disperses spontaneously, which means that it has a space-like rather than a time-like world line. In perfect analogy a mass point can be viewed as a local distortion of space-time. In euclidean space it can be smoothed away without leaving any trace, but not on a curved manifold. Mass generation therefore resembles distortion of a euclidean cover when spread across a non-euclidean surface. A given degree of curvature then corresponds to creation of a constant quantity of matter, or a constant measure of misfit between cover and surface, that cannot be smoothed away. Associated with the misfit (mass) a strain field appears in the curved surface. 

Data on c clohexene and a pinene aerosols were reported by Schwartz after a preliminary report from the Battelle Institute group. The experimental conditions and analytic techniques were identical with those just described for the toluene aerosol study. Here again, only the methylene chloride-soluble, water-insoluble fractions were studied. They accounted for about 7% and 65% of the total aerosol mass generated from cyclohexene and a pinene, respectively. Grosjean (unpublished data) has investigated the chemical composition of cyclopentene, cyclohexene, and 1,7-octadiene aerosols. Experiments were conducted in an 80-m Teflon smog chamber filled with ambient air, with irradiation by... 

Since the burning rate of a propellant is dependent on the burning pressure, the mass balance between the mass generation rate in the chamber and the mass discharge rate from the nozzle is determined by the pressure. In addition, the propellant burning rate in a rocket motor is affected by various phenomena that influence the mass balance relationship. Fig. 14.4 shows typical combustion phenomena encountered in a rocket motor, from pressure build-up by ignition to pressure decay upon completion of the combustion. 

Let us consider a propellant burning in a rocket motor as shown in Fig. 14.8. The mass generation rate in the chamber, ntg, is given by... 

Mass Generation Rate and Mass Discharge Rate... 

An adaptation of Eq. (14.38) for a nozzleless rocket indicates that the port area increases as the burning surface of the propellant regresses, decreases and Aj increases, and so the choked condition is varied. Thus, the thrust generated by the nozzleless rocket is determined by the relationship of the mass generation rate in the port and the mass discharge rate at the rear-end of the port.I - l... 

As for a rocket motor, the combustion pressure is determined by the mass balance between the mass generation rate and the mass discharge rate according to... 

Since the mass generation rate in the gas generator is dependent on the pressure therein and the mass discharge rate is dependent on the throat area of the nozzle attached to the end of the gas generator, the mass generation rate is altered by changing the throat area. Thus, a throttable valve is attached to the end of the gas generator. 

The mass generation rate in the gas generator is controlled by the variable flow system and the mixture ratio of fuel-rich gas to air in the ramburner is optimized. The burning rate is represented by the relationship r = ap", where r is the linear burning rate, p is the pressure, n is the pressure exponent of burning rate, and o is a con-... 

Fig.15.3 Fundamental concept of a variable-flow system as a function of mass generation rate and mass discharge rate.

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