Global efficiency

Liibberstedt [64] tested three different hydrocyclones for HeLa cell separation a 7 mm Bradley [67], a 10 mm Mozley (Richard Mozley Ltd., Redruth, UK), and a 10 mm Dorr-Oliver (Dorr-Oliver GmbH, Wiesbaden, Germany) (the dimension quoted here is the diameter of the cylindrical part of each hydrocyclone). The best results were obtained with the Dorr-Oliver hydrocyclone (Fig. 3), which produced a cell separation efficiency of 81 % when working at a pressure drop of 300 kPa and a flow rate of 2.8 L min When operating with two 10 mm Dorr-Oliver connected in series (the overflow of the first as feed for the second) at 200 kPa, the global efficiency of the arrangement was 94% [65]. These experimental values confirm the computational fluid dynamics (CFD) predictions that high levels of efficiencies for mammalian cells could be achieved with small diameter hydrocyclones [46]. 

Alkaline electrolysis is a mature technology. It features a good efficiency (-66% LHV), an excellent lifetime of cell (above 20 years currently), and a production of 99.8% pure hydrogen at 30 bars. This leads to a global efficiency of -24% (based on a heat/electricity conversion efficiency of -35%). The main issue is the large fraction of the production cost (-80%) tied to the consumption of electricity (typically 2.6 out of EUR 3.2/kg H2 at EUR 54/MWh) [3.4 out of USD 4.2/kg H2 at USD 70/MWh], Besides, progress is sought to reduce the investment cost. 

The thermochemical cycles (S-I > 850°C) or hybrid cycles (S-electrolysis > 850°C) still feature many uncertainties in terms of feasibility and performances. Uncertainties still exist in parts of the flow sheet and technologies needed to provide high temperature heat whether from solar or nuclear nature. Potential assets of thermochemical cycles lie in a theoretical potential for a global efficiency above 35% and a scaling law of the hydrogen plant after the volume of reactants instead of the total surface of electrolytic cells. In return, their practical feasibility and economic viability have to be entirely demonstrated. Especially, a global efficiency above 30% is to be demonstrated to compete with alkaline electrolysis. Moreover, the safety of co-located nuclear and chemical plants has to be demonstrated. 

Cryogenic facilities are needed to support low-temperature operations. A major consumer is cold water of 5 °C for acrylonitrile absorption, with a duty of 7.7 MW. The power W needed to extract the heat duty Qj can be roughly estimated by assuming a reversible Carnot cycle and global efficiency of 0.6, by using the relation ... 

Under optimum conditions of maximum power, the extraction flux J = /max is given by Eq. (4), or more generally, if there are leakage processes, by Eq. (6). The global efficiency of conversion of light into chemical potential at maximum... 

The global efficiency of the biological pump can be evaluated in terms of a global mean preformed nutrient concentration for surface water that is folded into the ocean interior. In the calculation of this mean preformed nutrient concentration, each subsurface water formation... 

The complete flow-sheet gives a global efficiency of the process equal to 35% with an estimated range of variation of 5%. For each section, the efficiency of each basic reaction has been studied and discussed and a set of components were designed that are able to operate. 

This gives a global efficiency of 36%. The VHTR is totally dedicated to the heating of the HYPP. Additional 100 MWe are coming from the grid. 

The application of UV spectrophotometry for the study of treatment processes is dependent on the user s needs. From primary treatments to the global efficiency estimation of the treatment plant, several applications are presented in this section. 

In the following paragraphs, the effects that can affect the luminance and the global efficiency of OLEDs will be discussed briefly. 

FIGURE 9.5 Schematic description of the parameters involved in the global efficiency of an OLED. 

Let us focus on the photophysical intermetallic communication 2 resulting from intramolecular 4f —>4f energy transfer and whose global efficiency is given in Eq. (75). 

The global efficiency of the traditional steam reformer plants, calculated as the ratio between the net heat value of the hydrogen stream produced and the total process heat duty requirement (reactor heat duty, steam generation, pre-heating of the reactant mixmre, PSA, and MDEA) is typically within the range 65-85%, depending on the plant size. 

The global efficiency ofthe graphG representing the network is defined as [Latora and Marchiori, 2001] ... 

Figure 3. Global efficiency relative variation as a function of group betweenness centrality measure.

For example, in [Crucitti et al, 2005] the authors use the global efficiency of G (defined from the minimum number of steps from node i to node j) to evaluate the vulnerability of three electric power systems in Europe under three different classes of damages D the removal of sets of one, two or three links. 

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