Mismatch loss

Since the effect of a Si02 cladding on mode shape is negligible, there is no mode mismatch loss or PDL associated with the junction between waveguide sections with and without claddings. Therefore it is possible to apply tailored cladding patches at discrete locations in a planar waveguide... 

To obtain the absolute sound attenuation in the coal slurry, the diffraction loss, the acoustic mismatch loss, the attenuation due to the Teflon window, and the oil coupling must be calculated. Thus, it is difficult to accurately determine the absolute attenuation. In practice, one measures the relative attenuation with respect to a standard. The attenuation of ultrasonic waves in a solid suspension is attributed to three major factors, namely, scattering, viscosity, and thermal effects. Although the presence of particles affects the fluid viscosity and thermal conductivity, the primary source of attenuation may be due to particle scattering. Hence, one may define the relative attenuation of the HYGAS coal slurry by comparing the slurry attenuation with that of the carrier fluid, i.e., the toluene/benzene mixture. This can be expressed by the equation... 

Also, we must add the mismatch loss. If the antenna has a VSWR < 2 (as typical for the arrays discussed here), the mismatch loss will be less than 0.5 dB. 

Although some improvement in matching can be obtained by using lossy elements, it is in general not recommended since the possible reduction in mismatch loss in general is more than canceled by deterioration of the efficiency. Only at frequencies lower than 100MHz should this be considered since most of the noise at these frequencies comes from the outside through the antenna in the form... 

Figure 18.22 Characterizations of the standalone elastomeric fluid metal patch antenna, a) xz- and c) yz-plane radiation patterns (including mismatch losses) at the original resonant frequency of the antenna in its relaxed state, and w/ 15% elongation along its x-axis. The antenna gain along (p and 0 orientations is defined as and G, respectively The antenna co- and cross-polarization along +z-axis are in parallel to the x- and y-axis. c) Simulated and measured reflection coefficients of the antenna in different states. The corresponding coordinate system is presented in Figure 18.21.

Experimental results on radiation patterns, including mismatch losses, at 1.46 GHz, of the relaxed suid flexed... 

The measured total efficiency of the standalone stretchable patch antenna including mismatch losses is 36.9% in its relaxed state at 1.46 GHz. Straining the patch to 15% along its x-axis leads to significant total efficiency decrease of 33.8%. In the intermediate states with the strains between 5% and 10%, the total efficiency of 11.5% and 5.8% is achieved according to the experiments. 

In addition, one other feature of the prefractionator arrangement is important in reducing mixing effects. Losses occur in distillation operations due to mismatches between the composition of the column feed and the composition on the feed tray. Because the prefractionator distributes component B top and bottom, this allows greater freedom to match the feed composition with one of the trays in the column to reduce mixing losses at the feed tray. 

Another U.S. policy to attain energy independence was to force all Alaskan North Slope crude oil to he consumed inside the United States and not be allowed to he exported. The problem was that North Slope crude oil is relatively heavy and not suitable for west coast fuel needs. The mismatch of supply and demand caused California refineries to sell heavy distillate fuels abroad and import lighter fuel additives. Furthermore, the forced selling of Alaska crude oil on a very saturated west coast market caused Alaska crude prices to he 1 to 5 per barrel less than the international price, resulting in less oil exploration and development in Alaska. The upshot of all this was lower tax revenue, a loss of jobs in the oil fields, and less oil exploration and development on the North Slope. The United States actually exported heavy bunker fuel oil at a loss, as opposed to the profit that could have been attained by simply exporting crude oil directly. 

The formation and dissolution of CaCOa in the ocean plays a significant role in all of these effects (34)- CaCOa is produced by marine organisms at a rate several times the supply rate of CaCOa to the sea from rivers. Thus, for the loss of CaCOa to sediments to match the supply from rivers, most of the CaCOa formed must be redissolved. The balance is maintained through changes in the [COa] content of the deep sea. A lowering of the CO2 concentration of the atmosphere and ocean, for example by increased new production, raises the [COa] ion content of sea water. This in turn creates a mismatch between CaCOa burial and CaCOa supply. CaCOa accumulates faster than it is supplied to the sea. This burial of excess CaCOa in marine sediments draws down the [COa] - concentration of sea water toward the value required for balance between CaCOa loss and gain. In this way, the ocean compensates for organic removal. As a consequence of this compensation process, the CO2 content of the atmosphere would rise back toward its initial value. 

Another important issue in multijunction cells is current matching. The individual currents must exactly balance otherwise a loss in efficiency occurs. A current mismatch can be easily revealed by measuring the spectral response [595]. If the currents are matched, then the quantum efficiency is flat over a wide range of wavelengths. If one of the cells is limiting the current, then the observed quantum efficiency is not flat, and in fact is the quantum efficiency of the current-limiting cell. 

The primary requirement for making any connection is to minimise the optical power that is lost in it. Intrinsic losses result from technological variations of the fibres to be connected i.e. core area mismatch, numerical aperture mismatch, and profile mismatch. These obvious errors can only be omitted by proper matching of connected fibres or additional optical elements should be used. Contrary to the intrinsic losses, extrinsic ones can be corrected by a mechanical alignment. Extrinsic losses are caused if ends of the fibres are in some distance and the light from the input fibre cannot be collected by the sink fibre. A similar situation with power losses occurs in lateral displacement and angular misalignment. 

The total output photovoltage must exceed the thermodynamic potential difference for water splitting (1.229 V at 25°C), the energy level mismatches for the anodic and cathodic processes, and the polarization loss or overvoltages due to kinetic, diffusion, and IR potential losses in the bulk of electrolyte. 

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