Penetrating power

X-rays may be detected either photographically or with an ionization counter. They have great penetrating power which increases with their frequency, and owing to this are used to photograph the interior of many solid objects, notably the human body and in monitoring for faults in construction. 

The diffraction pattern consists of a small number of spots whose symmetry of arrangement is that of the surface grid of atoms (see Fig. IV-10). The pattern is due primarily to the first layer of atoms because of the small penetrating power of the low-energy electrons (or, in HEED, because of the grazing angle of incidence used) there may, however, be weak indications of scattering from a second or third layer. 

The viscosity of an adhesive directly influences its penetration into a substrate as the viscosity increases, the penetrating power decreases. It also determines the amount of mileage or spread that can be obtained. An optimum viscosity exists for each substrate and each set of machine conditions and must be achieved in order to manufacture an efficient adhesive. Poly(vinyl acetate) emulsions are frequently too low in viscosity to be metered efficiently or to perform well as adhesives by themselves. They must be bodied to working viscosities, eg, by adding thickeners. 

Radiographic examination is either by x-rays or by gamma radiation. The former has greater penetrating power, but the latter is more portable. Few x-ray machines can penetrate beyond 300-mm (12 -in) thickness. 

Durchfarbevermogen, n. penetrating power, durchfaulen, v.i. rot thru, rot completely, durchfeuchten, v.t. soak saturate with moisture. 

It has often been said that the penetrating power of x-rays is their most remarkable property. As concerns analytical chemistry, however, the simplicity of their spectra deserves at least equal emphasis—after all, this simplicity makes for simple analytical methods, in which even the deviations are often predictable. Both the penetrating power (small chance of being absorbed) and the simplicity may be attributed to the high energy of x-rays. More precisely, these important properties are... 

The nuclear reactor also must be shielded against the emission of radioactive material to the external environment. Suitable radiation controls include both thermal and biological shielding systems. Radiation from alpha particles (a rays) and beta particles ((3 rays) has little penetrating power, but gamma rays have deep penetration properties. Neutron radiation is, however, the primary area of risk. Typically, extremely thick concrete walls are used as a neutron absorber, but lead-lined concrete and special concretes are also used. 

Second in penetrating power is (3 radiation. These fast electrons can penetrate about 1 cm into flesh before their electrostatic interactions with the electrons and nuclei of molecules bring them to a standstill. 

Radiation Relative penetrating power Shielding required... 

Distinguish a, (3, and -y radiation by their response to an electric field, penetrating power, and relative biological effectiveness (Sections 17.1 and 17.6). 

The efficacy of ethylene oxide treatment depends upon achieving a suitable concentrahon in each article and this is assisted greatly by the good penetrating powers of the gas, which diffuses readily into many packaging materials ineluding mbber, plastics, fabric and paper. This is not without its drawbacks, however, since the level of... 

Formaldehyde gas for use in sterilization is produced by heating formalin (37% wA aqueous solution of formaldehyde) to a temperature of 70-75°C with steam, leading to the proeess known as LTSF. Formaldehyde has a similar toxicity to ethylene oxide and although absorption to materials appears to be lower similar desorption routines are leeommended. A major disadvantage of formaldehyde is low penetrating power and this limits the packaging materials that eanbe employed to principally paper and eotton fabrie. 

Si(Li) spectroscopy, with the capability of simultaneous quantitative analysis of 72 elements ranging from sodium through to uranium in solid, liquid, thin film and aerosol filter samples. The penetrating power of protons allows sampling of depths of several tens of microns, and the beam itself may be focussed, rastered or varied in energy. The use of a proton beam as an excitation source offers several advantages over other X-ray techniques, for example there is a higher rate of data accumulation across the entire spectrum which allows for faster analysis. 

Dry heat is widely used to sterilize glassware and equipment parts in manufacturing areas for parenteral products. It has good penetration power and is not as corrosive as steam. However, heat-up time is... 

The penetrating power of a shaped charge is approximately proportional to the cube of its diameter, but also very dependent on maintenance of exact axial symmetry during construction. It is also proportional to the detonation pressure of the explosive used, so that suitable fillings are cast Pentolite or RDX/TNT. Well-known applications of shaped charges are in the British PIAT and American bazooka. 

The gamma ray is a photon of electromagnetic radiation with a very short wavelength and high energy. It is emitted from an unstable atomic nucleus and has high penetrating power. 

Gamma radiation has a very high penetrating power. A small fraction of the original stream will pass through several feet of concrete or several meters of air. The specific ionization of a gamma is low compared to that of an alpha particle, but is higher than that of a beta particle. 

Neutrons have no electrical charge and have nearly the same mass as a proton (a hydrogen atom nucleus). A neutron is hundreds of times larger than an electron, but one quarter the size of an alpha particle. The source of neutrons is primarily nuclear reactions, such as fission, but they are also produced from the decay of radioactive elements. Because of its size and lack of charge, the neutron is fairly difficult to stop, and has a relatively high penetrating power. 

The depth of focus, or penetrating power, of a lens is the maximum... 

Gas Ionization Counters A common gas ionization counter is the Geiger-Muller counter where the electronic pulses derived from the ionization process are registered as counts. The instrument can be adjusted to detect only radiation with a desired penetrating power. 

The great advantage of Mossbauer spectroscopy for catalyst research is that it uses 7-radiation of high penetrating power such that the technique can be applied in situ. An economic advantage is that the technique is relatively inexpensive. The price is about a factor of ten less than equipment for electron microscopy or photoelectron spectroscopy. 

The high penetrating power of X-rays makes them eminently suitable for investigations of a catalyst under operating conditions inside a reactor. Figure... 

Gamma rays (y) have high penetrating power and are not deflected by electric or magnetic fields. Beta particles ( 3) have a lower ionizing power and greater penetrating power than alpha particles (a). 

Evidence was presented that thallous ethylate did not penetrate or alter the crystalline parts of the fiber. Moreover, it was possible to conduct the thallation with different solvents for thallous ethylate. When this was done with normal ethers, the extent of methylation was observed to decrease as the molecular volume of the thallous ethylate solvent increased. These results suggested that accessibility is dependent upon the penetrating power of the ether solvent. Amorphous cellulose was, therefore, defined as the percentage of cellulose wetted by an ether of zero molecular volume and was estimated by determining methylation-molecular volume values for three or more straight-chain ethers, plotting the data and extrapolating to obtain methoxyl content for an ether of zero molecular volume. The amount of cellulose corre-... 

Which of the following lists the types of radiation in the correct order of increasing penetrating power ... 

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