Resolution tests

Dr. Taylor. Yes, we can do this when suitable precautions have been taken. In fact, we have for some years past made use of a resolution test in which two successive pictures are taken of the same field. The contamination problem has been largely overcome in recent years, as you suggest. 

To monitor the progress of the reconstruction, the resolution test would be performed as a function of particle numbers. As shown in Fig. 6, the resolution would be expected to improve as the number of particles increases. Thus such a plot could allow the prediction of the number of particles needed to achieve a certain resolution. The required number of particles varied somewhat in practice (Table I), probably because of variations in the robustness of icosahedral symmetry in the particle, the image quality, as well as the effectiveness of the data processing procedures used. It should be pointed out that the FSC should approach unity at low resolution and generally decrease rapidly closer to the resolution limit for perfectly icosahedrally ordered particles. The presence... 

Figure 7 shows the result of a spatial resolution test with a delay-line read-out The result was obtained with a Xenon-C02 (90 %-10 %) gas-filUng, at normal pressure. The width of the peaks in 70 pm FWHM. The delay-line in the test had an overall delay of 1 microsecond and an impedance Zdl = 500 2. The signal charge was about 0,6 picocoulomb. 

Vertical cross-sections oriented in a SW-NE direction (Fig. 12) reveal a number of interesting features. Striking features in the P-wave image are the high-velocity anomalies labelled X and Y (Fig. 12). The tabular anomaly, Y, extends to the resolution depth limits (c. 500 km). It is not clear how connected these anomalies are, but resolution tests suggest it would be difficult to resolve... 

It is unclear to what extent the structure below 300 km is related to Archaean processes. The resolution tests of Sol et al. (2002) show that a slab structure that is continuous to >500 km would produce an image very similar to that in Figure 12 and may suggest that the transition-zone high-velocity anomaly (Y) is connected or related to the shallower anomaly (X). There are at least four possible explanations for the deeper high-velocity anomaly, as follows. (1) Slab material extends continuously from the surface to the base of the transition zone. This palaeo-slab has survived for well over 1 Ga and therefore the anomaly cannot be thermal in origin and for some reason it has not been mechanically eroded from the base of the continental root. (2) Material has delaminated from the base of the cra-... 

System suitability testing is an integral part of many analytical procedures. The tests are based on the concept that the equipment, electronics, analytical operations and samples to be analysed constitute an integral system that can be evaluated as such. System suitability test parameters that need to be established for a particular procedure depend on the type of procedure being evaluated, for instance, a resolution test for an HPLC procedure. 

The USP definition of robustness equals that of the ICH (3) The robustness of an analytical procedure is a measure of its capacity to remain unaffected by small, but deliberate variations in method parameters and provides an indication of its reliability during normal usage. A robustness test is the experimental setup used to evaluate method robustness. It quantifies the insensitivity of the results for a method transfer to another laboratory or instrument. The ICH guidelines also state that One consequence of the evaluation of robustness should be that a series of system suitability parameters (eg., resolution tests) is established to ensure that the validity of the analytical procedure is maintained whenever used (3). 

Lineshape and resolution tests on other nuclei follow a similar procedure to that above. Not all nuclei available with a given probe need be tested and typically only tests for inner and outer coil observations on multinuclear probes are required. This means the second test will often involve carbon-13 for which two samples are in widespread use the ASTM (American Society for Testing and Materials) test sample (40% p-dioxane in deuterobenzene also used for the sensitivity test) or 80% benzene in deuteroacetone. In either case on-resonance continuous-wave (CW) decoupling of protons should be used as this provides improved results for a single resonance relative to broadband decoupling. Rather long (30-40 s) acquisition times will be required for a well shimmed system. 

RT=diffraction resolution test RET=reduced exposure time LUC=large unit cell test ... 

Fig. 15. Negative tone relief patterns formed in a covalent-type photosensitive polyamic ester film using the process shown in Figure 11. (a) Resolution test pattern showing 40 /rm features in a 40-/xm film, (b) Resolution of 5 p.m lines and space patterns in a 18-jum film. Courtesy of Arch Chemicals, Inc.

G1400 doublet-resolution test (9 doublets, 18 peaks in 1 spectrum) A 18 1.00 ... 

If a possible rider is seen on the flank of a peak, how can one improve the resolution. Testing the peak homogeneity and improvement of the resolution are related questions. For both, a three-step concept can be applied. 

Characterization of selected substances suggested as candidates for a DSC resolution test[666]... 

Column Resolution Test Mixture— A mixture of 1 % each of n-C, and /i-C,g paraffin in a suitable solvent, sudi as n-octane, for use in testing the column resolution. (Warning—See Note 7.)... 

Column Resolution—The column resolution, influenced by both the column physical parameters and operating conditions, affects the overaU determinatioo of boiling range distribution. Resolution is therefore specified to maintain equivalence between different systems (laboratories) employing this test method. Resolution is determined using Eq 1 and the C, and C g paraffins from a column resolution test mixture analysis (see 8.8 and Section 10), and is illustrated in Fig. 1. Resolution (R) must be at least three and not more than ten, using the identical conditions employed for sample analyses ... 

Resolution—Analyze an aliquot of the column resolution test mixture (see 7.7) utilizing identical conditions as used in the analysis of samples. The resolution of /i-Cie and n-C,g n-paraffin peaks must be between three and ten when calculate in accordance with the following equation (refer to Fig. 1) ... 

However, there are three different tests for resolution, and there is no agreement as to which method is best. Further, very few materials are suitable for resolution tests. In most problems, there is no need for resolutions of better than 5 A, and with most samples it would be difficult to prove resolution of below 10 A. Resolutions of 2-3 A were recently achieved for intercalation complexes of superconducting Ta 2, allowing direct observation of the crystalline lattice and its imperfections. Computer enhancement of high-resolution electron micrographs of stained and unstained catalase crystals show amazing... 

---