Strain resolution

Thermal Expansion Measurement. Thermal expansion measurements were made with a laser interferometer dilatometer (2Q) with a strain resolution of approximately 2x10 6. The temperature cycle for all tests went from room temperature to a maximum of 121°C (except where noted), down to -157°C and back to room temperature. Thermal strain data were taken at approximately 20°C increments with a 30-minute hold at each temperature to allow the specimen and interferometer to reach thermal... 

Table 7.4 gives an overview on the relation between strain resolution and frequency range for a strain measurement task. From the users point of view, for most applications the tunable filter technique is a popular choice. If,... 

Interrogation technique Frequency range Strain resolution... 

Description Longitudinal strain sensitivity Transverse strain sensitivity Temperature sensitivity Strain resolution Spatial resolution Time resolution Measurable strain range... 

The spatial strain resolution depends on the strain level. This is a displacement measurement technique. 

Force Range 10N minimum, resolution 0.002 N Displacement/strain resolution IN-m, range 1000pm Sample size maximum 52.5 x 12.8 x 8.0mm... 

F(Hmally this is true only fix very small strains. As fer as viscoelastic measuronents are concerned the coupling of strain and strain rate (frequency) can be a serious problem. This is because small strain Ihnit will die cmrect G and G" profiles be obtained. The design of an instaumoit with good minimum strain resolution and good stress detection saisitivity is not, and the purchase of such an instrument can be costly. 

Microscopes are also used as analytical tools for strain analysis in materials science, detenuination of refractive indices and for monitoring biological processes in vivo on a microscopic scale etc. In this case resolution is not necessarily the only important issue rather it is the sensitivity allowing the physical quantity under investigation to be accurately detennined. 

Raman Microspectroscopy. Raman spectra of small soflds or small regions of soflds can be obtained at a spatial resolution of about 1 p.m usiag a Raman microprobe. A widespread appHcation is ia the characterization of materials. For example, the Raman microprobe is used to measure lattice strain ia semiconductors (30) and polymers (31,32), and to identify graphitic regions ia diamond films (33). The microprobe has long been employed to identify fluid iaclusions ia minerals (34), and is iacreasiagly popular for identification of iaclusions ia glass (qv) (35). 

The SPRTs are devices of superb accuracy and resolution, but they are fragile and can easily be broken. They can also be put out of caUbration by strain, iaduced by even slight mechanical shock or vibration. The principal use of SPRTs ia scieace and iadustry is to maintain the cahbrations of working thermometers. 

Fig. 2. Karyotype of 10 S. cerevisiae strains. Intact chromosomes have been separated electrophoreticaUy by size in a TAPE gel. (a), gel mn to separate most chromosomes. Large chromosomes are at the top, smaller at the bottom. Since most strains are polyploid, more than 16 bands may be observed, (b). Chromosomes from the same strains have been separated in a gel mn to enhance resolution of the smaller chromosomes, corresponding to the 4—5...

For example, a 10 GPa (total strain = 0.06) shock wave in copper has a maximum total strain rate 10 s [21] the risetime would thus be (eje) 0.6 ns. For uniaxial-strain compression, y averaged over the entire shock front. The resolution of the shock wave in a large-scale, multidimensional finite-difference code would be computationally expensive, but necessary to get the correct strength f behind the shock. An estimate of the error made in not resolving the shock wave can be obtained by calculating dt/dy)o with y 10 s (the actual plastic strain rate) and y 10 s (the plastic strain rate within the computed shock wave due to a time step of 0.06 qs). From (7.41) with y = 10 s (actual shock wave) and y = 10 s (computation) ... 

Besides phase identification XRD is also widely used for strain and particle size determination in thin films. Both produce peak broadenings, but they are distinguishable. Compared to TEM, XRD has poor area resolution capability, although by using synchrotron radiation beam diameters of a few pm can be obtained. Defect topography in epitaxial films can be determined at this resolution. 

Given limits to the time resolution with which wave profiles can be detected and the existence of rate-dependent phenomena, finite sample thicknesses are required. To maintain a state of uniaxial strain, measurements must be completed before unloading waves arrive from lateral surfaces. Accordingly, larger loading diameters permit the use of thicker samples, and smaller loading diameters require the use of measurement devices with short time resolution. 

High-resolution dilatometric measurements have revealed the appearance of anisotropy in the cubic-phase thermal strain in the precursive temperature region for the soft-mode martensitic transformations in VaSi/ Ni-Al, In-Tl/ and SrTiOa In the case of Ni-Al and SiTiOa, the onset temperatures for the strain anisotropy are close to those at which the appearance of central peak behaviour occurs. 

The thermal strain measurements were made in a low-temperature, high-resolution, three-terminal, capacitance dllatometer identical to the design of White and Collins."... 

Esterases have a catalytic function and mechanism similar to those of lipases, but some structural aspects and the nature of substrates differ [4]. One can expect that the lessons learned from the directed evolution of lipases also apply to esterases. However, few efforts have been made in the directed evolution of enantioselective esterases, although previous work by Arnold had shown that the activity of esterases as catalysts in the hydrolysis of achiral esters can be enhanced [49]. An example regarding enantioselectivity involves the hydrolytic kinetic resolution of racemic esters catalyzed by Pseudomonasfluorescens esterase (PFE) [50]. Using a mutator strain and by screening very small libraries, low improvement in enantioselectivity was... 

Asymmetric alcoholyses catalyzed by lipases have been employed for the resolution of lactones with high enantioselectivity. The racemic P-lactone (oxetan-2-one) illustrated in Figure 6.21 was resolved by a lipase-catalyzed alcoholysis to give the corresponding (2S,3 S)-hydroxy benzyl ester and the remaining (3R,4R)-lactone [68]. Tropic acid lactone was resolved by a similar procedure [69]. These reactions are promoted by releasing the strain in the four-membered ring. 

In order to investigate the friction properties of lubricant film in TFL, an apparatus with a floating device was developed by Shen et al. as shown in Fig. 17 [48]. The steel ball is fixed so that it does not roll in the experiment and a pure sliding has been kept. The measuring system of micro-friction force is composed of a straining force sensor with a resolution of 5 yu,N, a dynamic electric resistance strain gage, an AD data-collecting card, and a computer. 

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