Efficiency modelling

A. Karma, W.-J. Rappel. Phase field method for computationally efficient modeling of solidification with arbitrary interface kinetics. Phys Rev E 55 R3017, 1996 A. Karma, W.-J. Rappel. Quantitative phase field modeling of dendritic growth in two and three dimensions. Phys Rev E 57 4111, 1998. 

Vehicles None Two energy-efficient models. Three or four automobiles and a recreational vehicle. 

For example a consumer wishes to buy a new refrigerator. The high-efficiency model (offering services identical to the standard model) costs 60 more but uses 400 kWh/year less electricity. The consumer expects to keep the refrigerator for ten years and has a discount rate of 5 percent. The cost of conserved energy in this case is calculated as follows ... 

The efficient heat pump reduces energy use by 1,676 kWh per year on average. Is the efficient model heat pump a good investment Suppose the incremental cost of the efficient unit, as compared with the less efficient unit, is 1,000, and electricity cost 10 cents per kWh. With this price of electricity, the efficient heat pump reduces electricity costs by 167.60 per year. Taking a simplified approach for purposes of illustration and assuming that each unit lasts indefinitely and has no repair, maintenance, or replacement costs, and ignoring possible tax effects, the internal rate of return may be calculated as 1,000= 167.60/r, which is 16.76 percent per year. If the household can borrow money at, say, 10 percent per year and earn 16.76 percent, the investment makes economic sense. If we assume a 10 percent discount rate, the present value of the investment is 1,676, which exceeds the initial investment cost. The net present value is 676, which indicates that the investment is feasible. 

Efficient models of water heaters have thicker insulation, up to three inches thick, on some of the most efficient electric water heaters. Another means to increase efficiency is installing heat traps, or anti—convection devices, on the inlet and outlet pipes. Standard heat traps consist of short pipe nipple containing a small plastic ball. On the inlet side the ball is lighter than water and floats up to seal the inlet pipe. On the outlet side the ball is heavier than water and sinks against the seal. This prevents the heated... 

Fig. 2 (left panel) shows that by adopting the a calibration by Ludwig et al. (1999), we obtain evolutionary tracks very similar to those obtained by means of the Full Spectrum Turbulence (FST) model (Canuto, Goldman Mazzitelli 1996), which is also known to be a high efficiency model. 

We found that smaller shells of dynamically-restrained water molecules yielded active sites that are in broad structural terms similar to those obtained using much larger solvent shells of unrestrained molecules, without the artifacts and distortions that were apparent when restraining potentials were not used.48 This trend suggests that shells of restrained water would be an efficient model for bulk solvent in both active-site MD simulations and unconstrained-protein dynamics.49 Moreover, we found that the value of... 

An attempt has been made by Tsouris and Tavlarides[5611 to improve previous models for breakup and coalescence of droplets in turbulent dispersions based on existing frameworks and recent advances. In both the breakup and coalescence models, two-step mecha-nisms were considered. A droplet breakup function was introduced as a product of droplet-eddy collision frequency and breakup efficiency that reflect the energetics of turbulent liquid-liquid dispersions. Similarly, a coalescencefunction was defined as a product of droplet-droplet collision frequency and coalescence efficiency. The existing coalescence efficiency model was modified to account for the effects of film drainage on droplets with partially mobile interfaces. A probability density function for secondary droplets was also proposed on the basis of the energy requirements for the formation of secondary droplets. These models eliminated several inconsistencies in previous studies, and are applicable to dense dispersions. 

These two lines of investigation illustrate the important advances made in this field since the early theoretical interpretations of biological electron transfer processes. Hence, they allow one to envisage the understanding of these processes at the molecular level, and the synthesis of efficient model systems [86, 194]. 

Lamdan, Y., Woleson, H. J. Geometric Hashing a general and efficient model-based recognition scheme. 

What is the challenge for in silico ADME-Tox modeling In our point of view, the challenge is how to build up an accurate, reliable, and efficient model with good applicability. To answer this question, we may review the procedure of constructing an ADME-Tox model. The basic procedure of QSAR model construction is shown in Figure 2. 

The statistical techniques associated with response surface methodology are concerned primarily with two aspects of the experimentation process the construction of experimental designs that yield data to permit the efficient modeling of the response surfaces, and the analysis of the experimental data and derived response surfaces. 

Most tray efficiency models are based on Lewis case 1 with vapor perfectly mixed between trays. For case 1, Lewis derived the following relationship ... 

Most of the more previous attempts to correlate carcinogenic potency with structural features of benzenoid hydrocarbons are related to the mechanism outlined above. The different quantitative models that have been developed can be distinguished with regard to the number of independent variables. One-variable theories (e.g. the so-called bay-region theory [94]) are normally inferior compared to two- [95] and three-variable theories which refer more explicitely to the different and partly competing metabolic reaction pathways. A particularely efficient model has been developed by v. Szentpaly [96]. In his so-called MCS model three important influences on carcinogenic potency are taken into account M, the initial epoxidation... 

The advantage of the effective Hamiltonian (7), beside the reduced space of nuclear coordinates, is that it involves effective force constants (elements of the matrix K) which rapidly decrease with the distance between centres. This allows for efficient models involving only few force constants. Furthermore, the force constants can be calculated. For this purpose the local nuclear coordinates, at the centre n, are expanded in Cartesian displacements, uKa n ), of surrounding atoms ... 

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