Significant errors

For the purpose of calculating oil in place in the reservoir, it is the OWC, not the FWL, which should be used to define to what depth oil has accumulated. Using the FWL would overestimate the oil in place, and could lead to a significant error in tight reservoirs. 

Miscellaneous Methods At the beginning of this section we noted that kinetic methods are susceptible to significant errors when experimental variables affecting the reaction s rate are difficult to control. Many variables, such as temperature, can be controlled with proper instrumentation. Other variables, such as interferents in the sample matrix, are more difficult to control and may lead to significant errors. Although not discussed in this text, direct-computation and curve-fitting methods have been developed that compensate for these sources of error. ... 

Projections of market penetrations and contributions to primary consumption of energy from biomass are subject to much criticism and contain significant errors. However, even though these projections may be incorrect, they are necessary to assess the future role and impact of renewable energy resources, and to help in deciding whether a potential renewable energy resource should be developed. 

Nonetheless, these methods only estimate organ-averaged radiation dose. Any process which results in high concentrations of radioactivity in organs outside the MIRD tables or in very small volumes within an organ can result in significant error. In addition, the kinetic behavior of materials in the body can have a dramatic effect on radiation dose and models of material transport are constandy refined. Thus radiation dosimetry remains an area of significant research activity. 

As for the dielectric constant, when explicit solvent molecules are included in the calculations, a value of 1, as in vacuum, should be used because the solvent molecules themselves will perform the charge screening. The omission of explicit solvent molecules can be partially accounted for by the use of an / -dependent dielectric, where the dielectric constant increases as the distance between the atoms, increases (e.g., at a separation of 1 A the dielectric constant equals 1 at a 3 A separation the dielectric equals 3 and so on). Alternatives include sigmoidal dielectrics [80] however, their use has not been widespread. In any case, it is important that the dielectric constant used for a computation correspond to that for which the force field being used was designed use of alternative dielectric constants will lead to improper weighting of the different electrostatic interactions, which may lead to significant errors in the computations. 

Sensitive to lighting conditions degradation in storage contrast measurement from film subject to significant errors... 

Significant errors will arise if gas purity is not accounted for. It should be noted that the code lays down no conditions for this, and a figure of 99 / or better should be targeted. In order to obtain a good purity at the start, all pipe joints should be taped and the system evacuated to a low vacuum several times with intermediated purging with the test gas to remove the residual contaminants. 

The vane anemometer is not seriously affected by small deviations in alignment in the main flow direction. However, care is necessary since over 20° misalignment causes significant errors. With regard to providing a correction for fluid density, slightly different opinions exist. T35 Based on measurements, it is recommended- that the following density correction procedure be applied ... 

The question of whether it is necessary to break down a particular operation to a finer level of detail depends on whether the analyst believes that a significant error mode is likely to be revealed by a more fine grained analysis. For example, the operation "charge the reactor" may be an adequate level of description if the analyst believes that the likelihood of error is low, and/or the consequences of error are not severe. However, if this operation was critical, it could be further redescribed as shown below ... 

The purpose of the Critical Task Identification and Screening analysis is to reduce the amoimt of analysis required by focusing on tasks that have a significant error potential. The screening process essentially asks the following questions ... 

Note that determining the velocity at the inlet conditions to a pipe may create significant error when results are concerned with the outlet conditions, particularly if the pressure drop is high. Even the average of inlet and outlet conditions is not sufficiently accurate for some systems therefore conditions influenced by pressure drop can produce more accurate results w hen calculations are prepared for successive sections of the pipe system (long or high pressure). 

For most purposes, the integration can be extended from 0 to oo without introducing any significant error. Therefore, the following quantities can be defined for the dispersed phase ... 

Thus Cp m and CVm differ little from one another at low temperatures. The Debye low-temperature heat capacity equation (and other low-temperature relationships) we have summarized calculates Cp.m, as well as CV. m, without significant error. 

The velocity distribution and frictional resistance have been calculated from purely theoretical considerations for the streamline flow of a fluid in a pipe. The boundary layer theory can now be applied in order to calculate, approximately, the conditions when the fluid is turbulent. For this purpose it is assumed that the boundary layer expressions may be applied to flow over a cylindrical surface and that the flow conditions in the region of fully developed flow are the same as those when the boundary layers first join. The thickness of the boundary layer is thus taken to be equal to the radius of the pipe and the velocity at the outer edge of the boundary layer is assumed to be the velocity at the axis. Such assumptions are valid very close to the walls, although significant errors will arise near the centre of the pipe. 

These matrix elements are in a form that can be evaluated using standard quantum chemical methods. This evaluation is tedious and the earlier assumptions that we made will lead to significant errors in the matrix elements. On the other hand, we can conveniently use experimental information to approximate the diagonal matrix elements. 

It has been found that no significant error is introduced by combining the subgroups of an entire shell, using an average value of y for the entire K, L, M,. .. shell. With the Stoner distribution of electrons among the levels, this average value is... 

The temperature distribution in the flow direction for a fixed flow rate differs for different devices. This suggests that the heat transfer mechanism in these devices is not identical. The non-uniform (of about 20%) heat flux leads to conditions at which the wall temperature increases sharply. Idealizing the heat flux as uniform can result in a significant error in prediction of the temperature distribution. 

Depending on the particular design of inlet and outlet manifolds, the difference between the flow rates into some parallel micro-channels may be up to 20%. Idealizing the flow rate as uniform can result in significant error in prediction of the temperature distribution of a heated electronic device. 

If jiopen is erroneously interpreted as t, results from an open system give significant errors when the inlet and outlet Peclet numbers are less than about 100. If the openness of the system cannot be avoided, the recommended approach is to rescale g t) so that it has the correct mean ... 

The number of nuciei can be caicuiated from the mass of the sampie and the molar mass of the isotope. Because the molar mass of an isotope is nearly equal to its mass number, we can use the mass number without introducing significant error ... 

Non-linearity during progession of enzyme reaction or an initial lag phase which is undetected and may result in significant error. 

---