Large probes

In general D q,t) has a nontrivial q -dependence, so it is equally generally incorrect to replace D q,t)t with a -independent F t), hence the closing inequality in the above equation. In a viscoelastic fluid, such as most polymer solutions, the elastic moduli are frequency-dependent. The fluctuation-dissipation theorem then substantially guarantees that the random thermal forces on probe particles have nonzero correlation times, so probe motions in polymer solutions are not described by Markoff processes. The mathematically correct discussion in Berne and Pecora on Brownian particles, including Eq. 9.5, therefore does not apply to probes in polymer solutions. 

If the experiments of Turner and Hallet represented the entirety of the probe diffusion phenomenology, an optical probe experiment would simply have been a 

Extended searches of the spectrum on the time scale on which the spectrum would have decayed, if the Stokes-Einstein equation were correct in solutions of 1 MDa polyacrylic acid, found no sign of a spectral relaxation the spectrum had aheady decayed to the baseline. Lin and Phillies proposed that the discrepancy between Dp and the macroscopic q arises from shear tbinning in the probe diffusion process, namely the microviscosity found on the time and distance scales probed by the polystyrene spheres is far less than the macroscopic viscosity q. 

Lin used QELSS to study diffusion of 155 and 170 nm nominal radius titania spheres in a melt of 7500 Da polyethylene oxide(ll). Over a 75 °C temperature range, Dp changes by nearly two orders of magnitude. Comparison was made with the viscosity obtained using a cone-and-plate viscometer. The observed microviscosities were substantially less than the measured viscosity. An extrapolation procedure based on the apparent activation energy, as inferred from the temperature dependence of rj, was used to estimate an effective shear rate for probe diffusion 10 s , corresponding via y D/L to probe diffusion over atomic distances. Such distances would rationally be fundamental if the unit step for probe diffusion in a polymer melt were the displacement of a single layer of polymer chains. 

used hght scattering spectroscopy and ultracentrifugation to study the motion of prohes in poly-L-lysine (52 353 kDa) solutions, leading to 

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To analyze the data, first perform the vx- and ty-corrections and the time-to-speed transformation to make the velocity volume element the same for all data points, and then normalize each Doppler-selected TOF spectrum according to the averaged ID Doppler profile from several independent scans, I vz) = )T)(, vyS(vy vx 0,vz)dvy. Due to the large exothermicity of this reaction, the problematic density-to-flux transformation is not negligible (despite the large probe laser size used to minimize its effects) and needs to be accounted for (the wy-correction , see Sec. 3.3). By combining all the resulting TOF spectra, the product 3D velocity flux contour... 

Due to the large probe, the current density is sufficiently low to minimize radiation damage. This is in particular very important for investigations of organic and metal-organic substances. 

Kawabata T, Go N (2007) Detection of pockets on protein surfaces using small and large probe spheres to find putative ligand binding sites. Bioinformatics 529 516-529... 

Since this simulation will run for a long time and we have specified a small Maximum Step Size, a lot of data will be collected. PSpice normally collects voltage data at every node and current data through every circuit component This results in a large Probe data file that can take a long time to load and may cause memory problems. Since we are interested only in the input and output voltages, we will tell PSpice to collect data only at the input and output nodes, which will be marked with markers. 

Using large probe molecules43 the activity of the outer surface compared to the microporous activity of Beta materials can be determined. It was shown that for typical TEA-synthesized materials a large fraction of the activity observed could be attributed to the non-shape-selective outer surface acid groups. In order to minimize this non-shape-selective activity various techniques have been employed to passivate the outer surface. 

In principle, the four-probe method is more accurate than the two-probe, because in the former the interface impedance can be eliminated. However, it was reported that in different frequency ranges the membrane resistance and contact resistance could be easily separated. For example, in the two-probe method, the favourite frequency range is 100 to 500 kHz, while in the four-probe method the range becomes 1 to 100 kHz [11], Thus, both methods can yield reliable results, and the probe distance can affect measurement accuracy. Our experiments using both methods indicated that a large probe distance is required to obtain accurate results. 

It should also be noted that nitrogen is not an unbiased probe adsorbate. Obviously the surface accessibility for irregular materials depends on the size of the probe molecule a large probe cannot foUow the irregularity of the surface. Analyte molecules are usually larger than nitrogen molecules, and may not be able to penetrate aU pores. Thus only a fraction of the surface area is involved in analyte retention. To fulfill lUPAC recommendations for surface characterization methods [9], the most suitable method depends on the specific application. Recently an approach that involves IPR ion adsorption proved effective. The best probe to determine the packing area... 

In view of this fit, and of the fact that Rodger et al. used an impeller type that is in common use, Eq. (34) seems to be preferable for engineering estimates. However, the strong effects of variations in impeller design or system geometry which were not studied, and the possible influence of the relatively large probe on the flow, and the absence of measurements at other volume fractions or with other continuous phases, all must be considered as factors which indicate the need of caution in any application of Eq. (34). 

One important point should be emphasized here. This is the paucity of spacecraft data on the chemical composition and thermal structure of Venus lower atmosphere below —22 km altitude (von Zahn et al., 1983). About 80% of Venus atmospheric mass is below this altitude. Furthermore, altitudes of 0-12 km span the region where the atmosphere is interacting with the surface. However, with three exceptions we have no data on the chemical composition of Venus nearsurface atmosphere. First is the older measurements of CO2 and N2 from crude chemical experiments on the Venera 4-6 landers. Second, the water-vapor profile measured by the Pioneer Venus large probe neutral mass spectrometer. Third, the measurements of water-vapor and gaseous sulfur by spectrophotometer experiments on the Venera II-I4 landers. The gas chromatograph and mass spectrometer experiments on... 

Aug. 8, 1978 Pioneer Venus 2, bus probes Atm. entry Dec. 9, 1978 (bus, large probe, 3 small probes), first successful gc and ms analyses of atm... 

The typical patterns shown were generated using small probes. When large probes are used there may not be significant differences between temperature rises AT, and AT2. 

RPA consist of four steps (i) preparation and purification of RNA probes (ii) hybridization of probe with target RNA (iii) digestion of ss RNA (iv) analysis of protected fragments or quantification of label remaining in probe. As for SI analysis, it is important to maintain a probe excess to obtain pseudo-first-order kinetics while avoiding a large probe excess that would lead to excessive background. 

The composition of isolated metallic particles was determined with a JEOL-GEM 2010 analytical microscope by measuring the intensities of the of Pd L and Mn K emissions. With this instrument, the size of the probe can be reduced down to Inm. On large particles( d s 10 nm), or when the analysis is performed with a large probe size, the Pd/Mn ratio is close to the nominal composition. But most of the particles with a diameter smaller than 5 nm have a lower Mn content than the nominal composition, as can be seen in Table 1. The remaining Mn is dispersed on the support probably under the form of small particles which are not observed by electron microscopy because of a too low contrast. 

The interior microenvironment of BS-L micelles has been probed by fluorescence spectroscopy using a variety of large probes with both common BS-egg and -synthetic L micelles as functions of temperature [223,232,238], NMR of [ H]lecithins [235,237] differential scanning calorimetry [236], X-ray scattering [233], and electron spin resonance of spin-labels incorporated into lecithin and fatty acid chains [232]. 

Figure 4J12. The probe will most effectively distinguish features that are on the same size scale as the probe itself. (Top) Small molecular probes, as represented by the d orbitals, bind to either straight or curved DNA, with several probes fitting on one duplex. There may be local differences along the strand, but the overall observed binding will be an average of all sites. (Bottom) A large probe can span the curvature of the DNA, and differences in binding between straight and curved DNA may be more readily observable.

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