Penetration range

The Difficult Choice of Liquid Penetrant Range of Products. 

This study has been launched in order to provide quantified data about the compared performances of liquid penetrant product family and, finally, to introduce an acceptance criteria on performance of liquid penetrant range of products in RCC-M code which had no requirement on that point. 

The most widely used experimental method for determining surface excess quantities at the liquid-vapor interface makes use of radioactive tracers. The solute to be studied is labeled with a radioisotope that emits weak beta radiation, such as H, C, or One places a detector close to the surface of the solution and measures the intensity of beta radiation. Since the penetration range of such beta emitters is small (a ut 30 mg/cm for C, with most of the adsorption occurring in the first two-tenths of the range), the measured radioactivity corresponds to the surface region plus only a thin layer of solution (about 0.06 mm for C and even less for H). 

The spatial resolution of the CI SEM mode depends mainly on the electron-probe size, the size of the excitation volume, which is related to the electron-beam penetration range in the material (see the articles on SEM and EPMA), and the minority carrier diffusion. The spatial resolution also may be afiFected by the signal-to-noise ratio, mechanical vibrations, and electromagnetic interference. In practice, the spatial resolution is determined basically by the size of the excitation volume, and will be between about 0.1 and 1 pm ... 

Nonradiative surface recombination is a loss mechanism of great importance for some materials (e.g., GaAs). This effect, however, can be minimized by increasing the electron-beam energy in order to produce a greater electron penetration range. 

The grease X is sub-divided into consistency numbers, in accordance with the system proposed by the National Lubricating Grease Institute (NLGI) of the USA. These consistency numbers are related to the worked penetration ranges of the greases as follows ... 

However, analyses of the interface surrounded by some medium are not easy. When an interface of interest is exposed to a vacuum, electron-based or ion-based methods are available to determine the chemical composition and molecular structure of the top layers. The charged particles with limited penetration range result in a good vertical resolution. Buried interfaces are beyond the range of penetration. Photons, an alternative class of probe particles, have better ability for penetration. When the linear response to the incident electric field is analyzed, the vertical resolution is limited to the order of the wavelength, which is greater than the thickness of the top layers. 

A TMS-2 Thermomechanical Analyzer (Perkin-Elmer) was used to determine the glass transition temperatures of t e ionomer pseudo-IPNs at temperatures ranging from -100°C to +100°C and 0.01 mm of penetration range, 80g of penetrating weight, and a heating rate of 10°C/min. 

For the case in which the blend components were steamed together, the electron microprobe analyses showed the presence of silica on Additive R. This means that silica was transported from the cracking catalyst particles to the Additive R particles during the steam deactivation. The amount of silica transported and the distance the silica penetrated into the Additive R particles varied from particle to particle. The silica penetration ranged from about 10 microns to complete penetration of an entire particle. The amount of silica transported, expressed as the peak concentration observed in the outer section of the particle, varied from about 0.5% to about 8% SiO (estimates). 

The absorption properties of the accelerated electrons in the processed materials are the absorbed dose, the depth dose profile, the penetration range, and the dose rate. 

Electron penetration range in g/nP as the function of electron energy. (Courtesy of Energy Sciences, Inc.)... 

For thick substrates, backscattered electrons from the substrate decrease contrast and the minimum dimension increases to about 20 nm. For thick resists, and samples thick compared to the primary electron penetration range, electron scattering in the resist (forward scattering) and backscattering of electrons from the substrate, become more important than the electron interaction range. In these cases, exposure dose is sometimes altered according to the local pattern density to compensate for variations in the backscattered... 

In this manner the predicted curve 6f Figure 7, showing the effect of varying petrolene viscosity at constant level of penetration, was obtained. Other asphalts were prepared and analyzed for the above variables. The experimental points were placed on Figure 7. Agreement between the predicted curves and the experimental points is seen to be satisfactory. Figure 7 illustrates that in this penetration range, gel-type asphalts are obtained only from crudes of low aromatic content at low petrolene viscosities. As the petrolene viscosity is increased, asphalts from all crudes tend toward the viscous type. At lower penetrations, the curves are shifted upward, so that hard asphalts from the more aromatic crudes have rather complex flow properties. 

Type of radiation Penetration range in air (m) Shielding material... 

This effect (not seen up to now) can be explained as follows The brush represents a much lower (5 times) electron density than the silica body nevertheless the potential step vacuum-brash is sufficiently high (more than kT) to be a trap for positronium, and o-Ps is confined in the empty part. The radius of this part is smaller, but Ps wavefunction penetrates a thick brash layer only, and depending on electron density (see Eq.(3)), is much smaller than in pure silica, so the lifetime increases. If the potential step at vacuum-brash boundary is small the penetration range 1/x increases, but the alkane layer is sufficiently thick to prevent Ps reaching silica. Removal of the hydrocarbon phase increases the radius, but increases too, giving as a result lifetime shortening. 

The radionuclides Lu, with a mean tissue penetration range of 670 pm, and 4, with a mean range of 910 pm, are more effective for therapy of small tumours, while Ho, with a mean range of 3200 pm, is more useful for large tumours. Samarium-153, with a mean range of 1200 pm, is considered to be effective in the therapy of medium sized tumours. 

Radionuclide Half-life (d) Gamma emissions (keV) Average beta emissions (keV) Mean tissue penetration range (pm)... 

Time (a) Number of Soil 1ayers Penetration range (cm) Transportation velocity range (cm/a)... 

---