Sensitivity, defined

A number of risk importance measures have been defined for the interpretation of PSAs and for use in prioritization of operational and safety improvements. Some of these measures are similar to sensitivity defined as the total derivative (equation 2.8-1). 

The weakness of MC-ICPMS lies in the inefficiency by which ions are transferred from the plasma source into the mass spectrometer. Therefore, despite very high ionization efficiencies for nearly all elements, the overall sensitivity (defined as ionization plus transmission efficiencies) of first generation MC-ICPMS instruments is of the order of one to a few permil for the U-series nuclides. For most, this is comparable to what can be attained using TIMS. 

One can explicitly express the compliance matrix in terms of the elements of the principal charge sensitivities defining the generalized electronic-nuclear hardness matrix H of Equation 30.8, by eliminating AN and AQ from Equation 30.9 ... 

If it is not possible to include a particular element in the calibration solutions, it is possible to perform a semiquantitative analysis. This uses the response of those elements which are in the calibration solution, but predicts the sensitivity (defined as cps/concentration) for the missing element(s) by interpolating between the sensitivities of known elements. By plotting sensitivity against mass for all the elements present in the calibration solutions (Fig. 9.7) and fitting a curve through the points, it is possible to predict the sensitivity of the instrument for any particular mass number, and hence use this sensitivity to convert cps to concentration at that mass number. As can be seen from the figure, however, this is a very crude approximation, and any data produced in this way must be treated with some caution. 

Sensitivity defines the degree to which an assay can distinguish one compound from another of the same nature and an immunoassay is a function of the particular antibody molecules contained in the antiserum. Specificity of the antiserum is a function of the particular antigen used to immunize the animal. Affinity usually measures how strongly bound is the antigen to the antibody. Titer refers to the concentration level of, in the context of the usage, antibody contained in the obtained serum. 

Instead of the sensitivities Sj(t,p), in most applications we use the vectors of semi-logarithmic or normalized sensitivities, defined by... 

A mouth simulator is a valuable tool when determining what volatiles contribute to the flavor sensation during consumption of a food. This includes determining potency (e.g., Char-mAnalysis), intensity (e.g., OSME Acree and Barnard, 1994), contribution (e.g., omission tests), and effect of a compound on the flavor. Sample preparation with a mouth simulator gives a close representation of the human experience, without the expense and variability of using humans. The limitations of headspace sampling and detection sensitivity define the limits of the use of mouth simulators. 

Gebel HM, Bray RA. 2000. Sensitization and sensitivity Defining the unsensitized patients. Transplantation. 69 1370-1374. 

The infectivity of host cells varies considerably between viruses. A specific virus may have a great diversity of host ceils, while another may be capable of infecting only one type of cell. The sensitivity defines the capacity of the cell or animal to be infected. 

Detector Sensitivity - Minimum Detectable Concentration - (Xp). The detector sensitivity can also be defined in two ways. Firstly, as that concentration that will produce a signal equivalent to twice the noise. Secondly, it can be defined as that change in the physical property being measured that will provide a signal equivalent to twice the noise. The sensitivity defined in concentration units is more useful to the analyst as it allows the system concentration sensitivity and mass sensitivity to be calculated. 

A continuous analog output is provided from the 90° sensor and all the sensors are sampled every 2 sec. The molecular weight range extends from 10 to 10 Daltons and the rms radii from 10 to 50 nm. The total cell volume appears to be about 3 pi and the scattering volume is 0.02 p t. The detector has a sensitivity, defined in terms of the minimum detectable excess Rayleigh ratio of 5 x 10 cm which is difficult to translate into normal concentration units but appears to be equivalent to a minimum detectable concentration of about 10 g/ml. 

Sensitivity in atomic absorption is conventionally defined using the gradient of the calibration line for each element. In flame atomic absorption, it is expressed in terms of the concentration level of the clement (microgram per millilitre) producing an absorption of 1%, i.e. a relative absorbance of 0.0044. The sensitivity defined in this way essentially depends on the atomisation conditions geometry of the burner, equilibrium reactions, etc. 

Tables 1.1 and 1.2 also provide information about the NMR sensitivities of the various nuclei, listed as their receptivity relative to Si, with the absolute sensitivity defined by Harris (1984) as 7 C(I(I +1)) where C is the natural abundance of the nucleus and y is its gyromagnetic ratio. The relative receptivities of the quadmpolar nuclei in Table 1.2 have been adjusted by taking into account the fractional contribution of the central transition.

While sensitivity defines the minimal response of a system, the operational range gives the spread between the minimal noise level and the harmful overload level. For a force or torque sensor these limits have to be defined for all circumstances in which the sensor will be used (Fig. 7.12.1). 

We were engaged in study of impact sensitivity, defined as the so-called first reactiori , in the past [6,75]. Recently we also have undertaken a study... 

Sensitivity, defined as n-fold difference detection limit, is directly correlated to the number of iterations of analysis performed. 

The most sensitive absorption line of lead is 2170.0 A closely followed by the 2833.1 A line. The sensitivity, defined as the concentration for 1% absorption, is 0.5 ppm and a detection limit of about 0.1 ppm can be obtained. The 2833 A line is often preferred over the 2170 A line because it is less noisy, less subject to background absorption, and gives better linearity. 

However, a plot of hydrogen sensitivity (defined as the drain current change over the initial drain current) versus bias voltage shows different characteristics for forward and reverse bias polarity conditions at 500 ppm of H2, as shown in Fig. 5.11. For the forward bias condition, there is a maximum sensitivity obtained around 1 V and further increase of bias voltage reduces the sensitivity. 

Detector sensitivity has been defined as the minimum concentration of an eluted solute that can be unambiguously differentiated from the noise. The ratio of the signal to the noise for a peak that is considered decisively identifiable has been arbitrarily chosen to be two (a ratio employed in electronic theory). Thus, the sensitivity or minimum detectable concentration is that concentration that provides a signal equivalent to twice the noise level. Unfortunately, the sensitivity defined in this way will usually depend on the physical properties of the solute used for measurement and, thus, must be defined. 

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