Intrinsic spatial resolution

The primary results of these first experiments from each facility were primarily proof-of-principle. Hussey et al.9 used a MCP detector with intrinsic spatial resolution of 25 pm and overall image resolution of about 30 pm. With this setup, a test section was operated in a differential cell mode, with a minimum stoichiometric ratio of about 50 on both the anode and cathode. Due to cell motion, it was not possible to quantify the total water content in the cell, but relative changes in the through-plane water content were observed from open circuit voltage, and the water content increased as a function of current density. 

Advantages of fMRI compared with other iechnK nes are the noninsasi e nature of the technit Uo. reproducibility, speed of data acquisition, and high intrinsic spatial resolution. 

Radionuclide Production Method P Energy (Abundence) Intrinsic Spatial Resolution Ti/2phys Labeling Methods... 

As before, 1 , and represent the intrinsic and collimator resolution components. is the FWHM of the smoothing kernel required to yield an acceptable reconstruction. The intrinsic spatial resolution is the least important factor in this calculation, since it is usually a factor of 2 or more smaller than the other components. The trade-off between spatial resolution and count sensitivity is explicit in this equation. Decreasing R to improve spatial resolution will often require /loiter to become larger to compensate for increased noise. 

The intrinsic spatial resolution of the hybrid systems is comparable to that of the dedicated PET systems with a FWHM of 4 to 5 mm. However, the count sensitivity is at least an order of magnitude lower. This, along with the maximum count rate constraint, guarantees that the coincidence camera data will be very count poor and therefore require substantial low-pass filtering when reconstructed. As a result the quality of the reconstructed images is perceptibly worse than the dedicated PET images. In head-to-head comparisons, it has been found that the hybrid systems perform well on... 

Typical system spatial resolution and geometric sensitivity for pin-hole collimator apertures of 0.5 and 1 mm are plotted in Fig. 2.1(a). These calculations assumed an intrinsic spatial resolution of 1 mm and an aperture angle of 60°. As can be seen, the dependence of camera sensitivity decreases as the square of the subject to collimator aperture distance. Optimum configuration is thus achieved by placing the subject very close to the collimator aperture. Moreover, spatial resolution degrades approximately linearly with subject to collimator distance. 

The transmission electron microscope (TEM) is a choice instrument for the characterization of materials and devices at the nanoscale. Nanoparticles shape, and distribution can easily been determined by conventional TEM while the atomic resolution in real space capability offers the possibility to resolve their structure. In addition to this high intrinsic spatial resolution, TEM offers a number of signals which can be exploited to obtain chemical and stmctural information concerning the specimen (see, for example, Wang, 2000 ). Recent years have... 

Signal-to-noise considerations make most neutron-based explosive detection approaches very difficult to implement. The basis for combining multiple detection approaches (FNA, along with thermal gamma detection and neutron transmission spectroscopy) in a FNAP application that preserves the small volume advantage of a APSTNG remains to be established. There are distinct advantages associated with the API approach, but the concomitant reductions in available neutron flux, issues of tube lifetime, and the intrinsic poor spatial resolution must be taken into consideration for potential applications. 

We recently developed a systematic method that uses the intrinsic tryptophan residue (Trp or W) as a local optical probe [49, 50]. Using site-directed mutagenesis, tryptophan can be mutated into different positions one at a time to scan protein surfaces. With femtosecond temporal and single-residue spatial resolution, the fluorescence Stokes shift of the local excited Trp can be followed in real time, and thus, the location, dynamics, and functional roles of protein-water interactions can be studied directly. With MD simulations, the solvation by water and protein (residues) is differentiated carefully to determine the hydration dynamics. Here, we focus our own work and review our recent systematic studies on hydration dynamics and protein-water fluctuations in a series of biological systems using the powerful intrinsic tryptophan as a local optical probe, and thus reveal the dynamic role of hydrating water molecules around proteins, which is a longstanding unresolved problem and a topic central to protein science. 

One of the striking features of interstellar maser emission is the enormous intensity the maser lines have. In the case of water, the brightness temperature for the source W49 reaches about 1015 °K. Furthermore, the line widths of the observed lines are extremely narrow, typically only a few ten of kHz. Both properties, intense and narrow emission lines, are intrinsic indications of maser emission. It has been found that the angular size of all interstellar maser sources is very small, i.e. much smaller than the spatial resolution obtained with large single dish radiotelescopes. From long baseline interferometry, however, an upper limit has been placed on the apparent source size of about 0.002 seconds of arc (for W49 = 0.0003 , Orion = 0.001 ) (Hills et al., 1972), which, for example, at the distance of Orion, 450 pc, makes this particular water vapor source about 1/2 AU in size. This is comparable with the diameter of a red... 

Following a center-of-mass fixed coordinate system tied to an air mass, we use intrinsic coordinates to avoid artificial diffusion in the horizontal direction. Physical diffusion, therefore, is distinct and identifiable because the moving control volume can be allowed to undergo mass exchange with a neighboring air mass in a prescribed fashion. The question of horizontal spatial resolution is answered by a selection of source grid size, and the vertical resolution is set by the choice of the interval size in the z-direction. 

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