Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Sensitivity conservation

Freeze drying is employed primarily in the food industry.The frozen water is sublimated out of the product by means of vacuum. Residual water can be removed from the algae by heating under atmospheric pressure. The method is employed primarily to conserve sensitive materials. Freeze drying has to date been employed to dry algae only on a laboratory scale. In continuous-running industrial plants, 1.0 kWh of electric power and 2.1 kg of steam are required to evaporate 1 kg of water (batch 1.1 kWTi and 2.2 kg). ... [Pg.61]

Some of the other energy conservation approaches appHcable to dryers are interchange between the stack vapor and the incoming dryer air recovering sensible heat from the product use of waste heat from another operation for air preheat and using less, but hotter drying air. This last is limited to nonheat-sensitive materials. [Pg.230]

If uranium is internally cycled in coastal environments or if the riverine delivery of U shows some variability, residence time estimates (regardless of their precision) cannot be sensitive indicators of oceanic uranium reactivity. Based on very precise measurements of dissolved uranium in the open ocean, Chen et alJ concluded that uranium may be somewhat more reactive in marine environments than previously inferred. Furthermore, recent studies in high-energy coastal environments " indicate that uranium may be actively cycled and repartitioned (non-conservative) from one phase to the next. [Pg.45]

Another way to evaluate risks is to calculate the sensitivity of the total risk estimates to changes in assumptions, frequencies, or consequences. Risk analysts tend to be conservative in their assumptions and calculations, and the cumulative effect of this conservatism may be a substantial overestimation of risk. For example, always assuming that short-term exposure to chemical concentrations above some threshold limit value will cause serious injury may severely skew the calculated risks of health effects. If you do not understand the sensitivity of the risk results to this conservative assumption, you may misallocate your loss prevention resources or misinform your company or the public about the actual risk. [Pg.45]

The transfer of energy must proceed with net conservation of spin. In the usual case, the acceptor molecule is a ground-state singlet, and its reaction with the triplet state of the sensitizer will produce the triplet state of the acceptor. The mechanism for triplet photosensitization is outlined below ... [Pg.746]

Another aspect of cost reduction would be solvent economy. The need to preferentially select inexpensive solvents and employ the minimum amount of solvent per analysis would be the third performance criteria. Finally, to conserve sample and to have the capability of determining trace contaminants, the fourth criterion would be that the combination of column and detector should provide the maximum possible mass sensitivity and, thus, the minimum amount of sample. The performance criteria are summarized in Table 1. Certain operating limits are inherent in any analytical instrument and these limits will vary with the purpose for which the instrument was designed. For example, the preparative chromatograph will have very different operating characteristics from those of the analytical chromatograph. [Pg.362]

The rig selection will dictate the basic layout of the pad. Based on the necessary area needed to support its functions, ancillary equipment may be added in space conservative measures. In addition to the placement of various stationary rig site components, other operations such as logging, trucking and subsequent completion operations must be provided for. The most environmentally sensitive design will impact the least amount of area, and in that it will be the most economic. Potential pad sites and access routes should be laid out on a topographic map prior to the actual survey. At this time, construction costs can be estimated and compared. Figure 4484 shows such a layout. The cost of building a location includes the cost of reclamation such as any remediation. [Pg.1345]

In contrast to dissipative dynamical systems, conservative systems preserve phase-space volumes and hence cannot display any attracting regions in phase space there can be no fixed points, no limit cycles and no strange attractors. There can nonetheless be chaotic motion in the sense that points along particular trajectories may show sensitivity to initial conditions. A familiar example of a conservative system from classical mechanics is that of a Hamiltonian system. [Pg.171]

Changes in free energy and the equilibrium constants for Reactions 1, 2, 3, and 4 are quite sensitive to temperature (Figures 2 and 3). These equilibrium constants were used to calculate the composition of the exit gas from the methanator by solving the coupled equilibrium relationships of Reactions 1 and 2 and mass conservation relationships by a Newton-Raphson technique it was assumed that carbon was not formed. Features of the computer program used were as follows (a) any pressure and temperature may be specified (b) an inert gas may be present (c) after... [Pg.13]

The 3 isozymes are activated by G protein-coupled receptors through two different mechanisms [2]. The first involves activated a-subunits of the Gq family of heterotrimeric G proteins (Gq, Gn, Gi4, G15/16). These subunits activate the (31, (33 and (34 PLC isozymes through direct interaction with a sequence in the C terminus. The domain on the Gqa-subunit that interacts with the (3 isozymes is located on a surface a-helix that is adjacent to the Switch III region, which undergoes a marked conformational change during activation. The second mechanism of G protein activation of PLC 3 isozymes involves (3y-subunits released from Gi/0 G proteins by their pertussis toxin-sensitive activation by certain receptors. The 3y-subunits activate the 32 and 33 PLC isozymes by interacting with a sequence between the conserved X and Y domains. [Pg.969]

Al(III) is an example of an aquatic ion that forms a series of hydrated and protonated species. These include AlOrf Al(OH)J, Al(OH)3, and other forms in addition to AP. (For simplicity, we omit the H2O molecules that complete the structures of these complexes.) Most of these species are amphoteric (able to act as an acid or a base). Thus the speciation of Al(III) and many other aquatic ions is sensitive to pH. In this case, an aggregate variable springs from the conservation of mass condition. In the case of dissolved aluminum, the total dissolved aluminum is given by... [Pg.89]


See other pages where Sensitivity conservation is mentioned: [Pg.307]    [Pg.2061]    [Pg.327]    [Pg.388]    [Pg.428]    [Pg.429]    [Pg.253]    [Pg.286]    [Pg.75]    [Pg.405]    [Pg.2301]    [Pg.413]    [Pg.192]    [Pg.315]    [Pg.348]    [Pg.126]    [Pg.188]    [Pg.363]    [Pg.287]    [Pg.97]    [Pg.218]    [Pg.192]    [Pg.201]    [Pg.35]    [Pg.253]    [Pg.358]    [Pg.517]    [Pg.884]    [Pg.908]    [Pg.1213]    [Pg.1218]    [Pg.1318]    [Pg.550]    [Pg.173]    [Pg.55]    [Pg.248]    [Pg.144]    [Pg.145]   
See also in sourсe #XX -- [ Pg.184 , Pg.185 , Pg.186 ]




SEARCH



© 2024 chempedia.info