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Remains

If we vary the composition of a liquid mixture over all possible composition values at constant temperature, the equilibrium pressure does not remain constant. Therefore, if integrated forms of the Gibbs-Duhem equation [Equation (16)] are used to correlate isothermal activity coefficient data, it is necessary that all activity coefficients be evaluated at the same pressure. Unfortunately, however, experimentally obtained isothermal activity coefficients are not all at the same pressure and therefore they must be corrected from the experimental total pressure P to the same (arbitrary) reference pressure designated P. This may be done by the rigorous thermodynamic relation at constant temperature and composition ... [Pg.20]

To illustrate the criterion for parameter estimation, let 1, 2, and 3 represent the three components in a mixture. Components 1 and 2 are only partially miscible components 1 and 3, as well as components 2 and 3 are totally miscible. The two binary parameters for the 1-2 binary are determined from mutual-solubility data and remain fixed. Initial estimates of the four binary parameters for the two completely miscible binaries, 1-3 and 2-3, are determined from sets of binary vapor-liquid equilibrium (VLE) data. The final values of these parameters are then obtained by fitting both sets of binary vapor-liquid equilibrium data simultaneously with the limited ternary tie-line data. [Pg.67]

Using the ternary tie-line data and the binary VLE data for the miscible binary pairs, the optimum binary parameters are obtained for each ternary of the type 1-2-i for i = 3. .. m. This results in multiple sets of the parameters for the 1-2 binary, since this binary occurs in each of the ternaries containing two liquid phases. To determine a single set of parameters to represent the 1-2 binary system, the values obtained from initial data reduction of each of the ternary systems are plotted with their approximate confidence ellipses. We choose a single optimum set from the intersection of the confidence ellipses. Finally, with the parameters for the 1-2 binary set at their optimum value, the parameters are adjusted for the remaining miscible binary in each ternary, i.e. the parameters for the 2-i binary system in each ternary of the type 1-2-i for i = 3. .. m. This adjustment is made, again, using the ternary tie-line data and binary VLE data. [Pg.74]

Such step-limiting is often helpful because the direction of correction provided by the Newton-Raphson procedure, that is, the relative magnitudes of the elements of the vector J G, is very frequently more reliable than the magnitude of the correction (Naphtali, 1964). In application, t is initially set to 1, and remains at this value as long as the Newton-Raphson correotions serve to decrease the norm (magnitude) of G, that is, for... [Pg.116]

One further problem remains. Most of the n-butane impurity which enters with the feed enters the vapor phase in the first separator. Thus the n-butane builds up in the recycle unless a purge is provided (see Fig. 4.13a). Finally, the possibility of a nitrogen recycle should be considered to minimize the use of fresh nitrogen (see Fig. 4.136). [Pg.121]

One problem remains where to get the film transfer coefficients hi and hj. There are three possibilities ... [Pg.219]

In this accident, the steam was isolated from the reactor containing the unfinished batch and the agitator was switched ofiF. The steam used to heat the reactor was the exhaust from a steam turbine at 190 C but which rose to about 300°C when the plant was shutdown. The reactor walls below the liquid level fell to the same temperature as the liquid, around 160°C. The reactor walls above the liquid level remained hotter because of the high-temperature steam at shutdown (but now isolated). Heat then passed by conduction and radiation from the walls to the top layer of the stagnant liquid, which became hot enough for a runaway reaction to start (see Fig. 9.3). Once started in the upper layer, the reaction then propagated throughout the reactor. If the steam had been cooler, say, 180 C, the runaway could not have occurred. ... [Pg.264]

The effects of pollution can be direct, such as toxic emissions providing a fatal dose of toxicant to fish, animal life, and even human beings. The effects also can be indirect. Toxic materials which are nonbiodegradable, such as waste from the manufacture of insecticides and pesticides, if released to the environment, are absorbed by bacteria and enter the food chain. These compounds can remain in the environment for long periods of time, slowly being concentrated at each stage in the food chain until ultimately they prove fatal, generally to predators at the top of the food chain such as fish or birds. [Pg.273]

Plug-flow reactors have a decreasing concentration gradient from inlet to outlet, which means that toxic compounds in the feed remain undiluted during their passage along the reactor, and this may inhibit or kill many of the microorganisms within the... [Pg.315]

They are designed to improve effluents from secondary treatment processes by removing suspended material and with it some of the remaining BOD. [Pg.319]

Ultrafiltration. Ultrafiltration was described under pretreatment methods. It is used to remove finely divided suspended solids, and when used as a tertiary treatment, it can remove virtually all the BOD remaining after secondary treatment. [Pg.319]

Having explored the major degrees of freedom, the material and energy balance is now fixed, and hence the hot and cold streams which contribute to the heat exchanger network are firmly defined. The remaining task is to complete the design of the heat exchanger network. [Pg.363]

Before any matches are placed, the target indicates that the number of units needed is equal to the number of streams (including utility streams) minus one. The tick-off heuristic satisfied the heat duty on one stream every time one of the units was used. The stream that has been ticked off is no longer part of the remaining design problem. The tick-off heuristic ensures that having placed a unit (and used up one of our available units), a stream is removed from the problem. Thus Eq. (7.2) is satisfied if eveiy match satisfies the heat duty on a stream or a utility. [Pg.370]

When a match is placed, the duty needs to be chosen with some quantitative assessment of the match in the context of the whole network without having to complete the network. This can be done by exploiting the powers of targeting using a technique known as remaining problem analysis. ... [Pg.386]

Targets for number of shells, capital cost, and total cost also can be set. Thus remaining problem analysis can be used on these design parameters also. [Pg.387]

Figure 16.215 shows an alternative match for stream 1 which also obeys the CP inequality. The tick-off" heuristic also fixes its duty to be 12 MW. The area for this match is 5087 m , and the target for the remaining problem above the pinch is 3788 m . Tlius the match in Fig. 16.216 causes the overall target to be exceeded by 16 m (0.2 percent). This seems to be a better match and therefore is accepted. [Pg.388]

Figure 16.22c shows an additional match placed on the other branch for stream 3 with its duty maximized to 3 MW to tick off stream 3. No further process-to-process matches are possible, and it remains to place cold utility. [Pg.389]

Remaining problem analysis can be used to make a quantitative assessment of matches in the context of the whole network without having to complete the network. [Pg.397]

As each match is successively placed in the interval, the minimum number of matches can be achieved because there is one fewer stream to match and the CP ratio of the remaining streams (i.e., ratio of 2 CPh and 2 CPc of the remaining streams) in the interval still satifies the CP ratio between the composite curves. [Pg.427]

Hydrogen must be considered as a member of Group I in such cases as — CHO the hydrogen must be ignored and only the remaining element considered. See also Crum Brown s rule. [Pg.200]

However because of the equilibrium between the solid and dissolved undissociated AB, the concentration of the latter may be considered to remain constant and hence... [Pg.367]


See other pages where Remains is mentioned: [Pg.73]    [Pg.31]    [Pg.37]    [Pg.69]    [Pg.385]    [Pg.386]    [Pg.387]    [Pg.387]    [Pg.388]    [Pg.396]    [Pg.403]    [Pg.63]    [Pg.107]    [Pg.109]    [Pg.132]    [Pg.150]    [Pg.194]    [Pg.231]    [Pg.237]    [Pg.239]    [Pg.247]    [Pg.275]    [Pg.289]    [Pg.311]    [Pg.314]    [Pg.343]    [Pg.371]   


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Adsorption still remaining challenges

Advanced Decay, Dry, and Remains

Amount remaining to be excreted

Ancient remains

Ancient remains mummies

Archaeological textile remains preserved

Biogenic remains

Buried remains

Buried remains postburial interval

Buried remains postmortem interval

Cadaver decomposition remains

Challenges Remaining to Be Addressed

Chemical equilibrium A dynamic reaction system in which the concentrations of all reactants and products remain constant

Chemical reactions excess reactant remaining after

Confined limitations, remaining

Conjugate base What remains of an acid

Conjugate base What remains of an acid molecule after a proton is lost

Decomposed porcine remains with partial

Diffusion still remaining challenges

Elongation remaining with irradiation

Fossil remains

Fraction remaining

Frozen remains

Gaps remaining

Golden Rules Remain Unchanged

Half-life amount remaining

Hemicellulose hydrolysis remaining

Human Resources Remain a Function in Transition

Human remains

Human remains and

Human remains study

Key Issues Remaining to be Addressed

Key Remaining Questions

Least remaining operation

Mass remaining in replicate

Maximum remaining variation

Number of particles remaining in the percolation fractal

Once Established, Life Is to Remain Present in This Universe

Problems Remaining Today

Relative remaining activity

Remained catalyst life

Remaining Challenges

Remaining EC Member States

Remaining Issues

Remaining Problem Analysis

Remaining Questions and Research Needs

Remaining Species-Specific Differences

Remaining Unexploded Chemical Ordnance

Remaining activity

Remaining life

Remaining problems

Remaining questions

Remaining resin content

Remaining useful life

Remaining useful life RULER

Remains outside cluster system

Settlements, archaeological remains

Skeletal remains

Spent cartridge cases mercury remaining

Steps 4—9 Creation of remaining central branches

Stress remaining

Summary problems remaining

Surfactant content remaining

Template remaining/residual

Textile remains

The Self-Assembly of Vesicles and why they Remain in Solution

The Study of Human Remains

Waste remaining

Why Micelles are Formed and Remain in Solution

Why does egg white denature when cooked but remain liquid at room temperature

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