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Thermal influences

Condensed Explosives, Decomposition Thermal. Influence of Pressure and Temperature on. See under Decomposition Thermal of Explosives and Propellants. Influence of Pressure and Temperature in this Section... [Pg.186]

Impurities, such as grit, shreds of cotton, even in small quantities, sensitize an expl to frictional impact. That is why utmost cleanliness must be exercised in the preparation of expls. There are differences in the sensitivity of azides to mechanical and thermal influences. They have been correlated with the structure of the outer electronic orbits, the electrochemical potential, the ionization energy and the arrangement of atoms within the crystal. Functions of the polarizability of the cation are the plastic deformability of the crystals, and their surface properties. The nature of cation in an azide, such as Pb(Nj)2, has little effect on the energy released by the decomposition, which is vested in the N ion. The high heat of formation of the N2 molecule accounts... [Pg.514]

It becomes a problem in semantics to set a time limit for "development within which a process can be considered "spontaneous or "instantaneous . These two words seem to apply well to such extremely sensitive compounds as Nitrogen Triodide and Cupric Azide, which explode at the slightest touch when dry and, in addition, explode at a fairly low temperature. Attempts to correlate initiation in such cases with the attainment of a certain temperature seem unrealistic, especially in view of differences between relative sensitivity of different compounds to mechanical and thermal influences. For example, Mercuric Azide is so sensitive to impact that it explodes even under water, hut its heat sensitiveness is about the same as that for Cadmium Azide, which has been reported not to explode by percussion (Ref 5) Information about susceptibility of different explosives to spontaneous detonation is highly important from the viewpoint of safety. In Refs which follow are listed examples of spontaneous detonations of substances, some of them previously considered safe in this respect... [Pg.562]

If very hard materials (e.g., natural stone, or metal sheets) must be cut, the injection of abrasives into the water jet will support and accelerate the cutting procedure (see Fig. 1.4-5, bottom, right side). The water-jet cutting represents a very flexible production method which can be regarded as supplementary to LASER methods if thermal influences on the materials involved cannot be accepted. [Pg.13]

The limiting factor in the temperature effect is the thermal influence on the special sensor. [Pg.236]

Summarizing the maturation process we can observe that thermal influences commence with the initial compaction of the sediments, and in the early stages decarboxylation and hydrogenation are the main reactions. Continued burial increases thermal cracking, and true petroleum development commences—first with the heavy oils rich in ONS compounds. Deep burial causes increased splitting of C-C bonds, isotopic... [Pg.47]

As a rule, recrystallization cannot be used for the purification of organic metals. Recrystallization is usually performed under definite thermal influence and leads to dirtied, imperfect crystals. Ion radical salts are not thermally stable in solution. The direct donor-to-acceptor interaction is the best way to limit chemical impurities. In this case, the reaction mixture contains minimal amounts of substances that are not included in the structure of a given ion radical salt. The oxidation of donors in the presence of anions or ion exchange usually results in the formation of less pure crystals. [Pg.373]

The comparative optical photo with the same magnification gives the image of a polished surface without revealing structure elements. Structure transformation has been observed after deformational and thermal influences. Acoustomicroscope method of V(Z) - curves essentially increases possibility of obtaining information about investigated materials [3]. It allows to get the specific curves, for given materials, which are connected with elastic - mechanical constant ones. The example of such dependence for carbonaceous steel is demonstrated in Fig. 2. [Pg.452]

Table 3 lists examples of more than a dozen different chemical types of river water. Although Ca and HCO j" are generally dominant, Mg dominance over Ca + can be found in rivers draining various lithologies such as basalt, peridotite, serpentinite, dolomite, coal, or where hydro-thermal influence is important (Semliki). Sodium may dominate in sandstone basins, in black shales (Powder, Redwater in Montana), in evaporitic sedimentary basins (Salt), in evaporated basins (Saoura), and where hydrothermal and volcanic influence is important (Semliki, Tokaanu). rarely exceeds 4% of cations, except in some clayey sands, mica schists, and trachyandesite it exceeds 15% in extremely dilute waters of Central Amazonia and in highly mineralized waters of rift lake outlets (Semliki, Ruzizi). [Pg.2465]

The electrode configuration was stressed with a voltage impulse of nearly a sine-half-wave shape. This waveform was used to avoid thermal influence on the pollution layer that would occur on a permanently stressed sample. The leakage current was measured by a digital storage oscilloscope. [Pg.776]

No thermal influence on the sample No swelling of hydrophilic fibres... [Pg.171]

All these changes could be attributed to several factors that are discussed further. The main driving mechanism for ice regime is air temperamre. However, other parameters, such as water salinity, changes in sea depth, currents and water exchange, could significantly affect thermal influence. [Pg.214]

Photochemical Properties. A simple experiment was performed to compare the photochemical activity of the MP with the TM polymers. Solutions of TM1 and MP1 in quartz cuvettes with the same absorptivity were irradiated with 60 mj cm-2. The UV-Vis spectra before and after irradiation are shown in Fig. 8. A comparison of the absorption bands after 100 pulses shows that about 50% of TM1 and only 20% of MP1 are decomposed. This confirms clearly that the triazene-containing polymers decompose photochemically much more easily than the polymers without this group. It is important to point out that TM1 contains the same structural unit as MP1 (Scheme 3), but with the additional triazene unit in the repetition unit of the polymer. Irradiation of low concentrations of the polymer in solution can be interpreted as pure photochemical decomposition with nearly no thermal influences. [Pg.75]

The universal failure to realize infinitely sharp peaks and thus infinite resolution in separation techniques is most often due to the nonidentical activities of identical molecules. Driven by random entropic (or thermal) influences, they each take an individual and unique pathway in the system and as a consequence emerge separately - part of a smeared zone. [Pg.371]

Variations in the organic acid concentrations of diverse waters with respect to temperature suggest a strong thermal influence (Fig. 1). In Cenozoic age reservoirs maximum organic acid... [Pg.170]

The high sensitivity, excellent mechanical stability and the controllable thermal influences make the quartz-crystal microbalance a valuable tool. Determinations of the physical film thickness, however, may be more of a problem since the density pf of a thin film, depending on deposition method, chosen parameters and film thickness, is generally different from the density of the bulk material being considered. At film thicknesses below 100 nm, the density discrepancy is greater than with thicker films. This seems to be valid for metals as well as for dielectrics. It is, however, usually possible to reproduce the film density. For the deposition process, this demonstrates that the chosen vacuum and deposition parameters must be carefully controlled and maintained exactly to always attain the same film density. In its manner and after calibration, the geometrical film thickness can be exactly reproduced by quartz-crystal monitoring. [Pg.333]

In relation to radioactive waste disposal, during last years a number of laboratory results referring to thermal effects on saturated soils have been presented (Baldi et al. 1988, Towhata et al. 1993, Tanaka et al. 1997, Sultan et al. 2002, Burghignoli et al. 2000). However, results focused on the thermal influence on volume change behaviour of unsaturated soils are still limited (Wiebe et al. 1998, Romero et al. 2003). In particular, information concerning the temperature effects on the mechanical behaviour of highly expansive clays in unsaturated conditions is still scarce (Lingnau et al. 1996, Romero et al. 2001). [Pg.305]

An interesting relation has been observed between thermal conductivity and density for the rock types at Aspo, and this may be used to evaluate the spatial distribution of the thermal properties from density logging. There is currently insufficient knowledge concerning the variation of thermal properties at different scales. If the whole observed variation within a rock type is based on the cm-m scale, the thermal influence at the canister scale is small. This is due to the fact that the small-scale variation in thermal properties is mainly averaged out on the 5-10 m scale. If the main variation within rock types is on the 5-10 m scale, there is probably a significant effect on the canister temperature. However, it is likely that the observed variation occurs on both these scales. [Pg.364]

The radius of thermal influence / is defined implicitly as a solution of algebraic equation... [Pg.775]

This theory was followed by one in which it was assumed that the excess charge on the solution side is not localized at the interfacial plane on the solution side but is diffuse due to the net effect of the electrical and thermal influences (5,7). According to this model (diffuse layer theory) there is a parabolic dependence of the capacity on charge which is found to be in agreement with experiment at low concentrations. However, at higher concentration, the predicted values of the capacity are too high. [Pg.354]

Thermal influences can often affect the catalyst compositian. In many cases one or more metastable phases are formed from the active components or the support materials. Phase changes can limit the catalyst activity or lead to catalyst- bstrate interactions. We have already dealt with the transformation of y-Al203 into a-Al203 with its lower surface area. Another example is the phase transformation of Ti02 from anatase to rutile in V2O5/ Ti02/corundum catalysts for the oxidation of o-xylene to phthalic anhydride. [Pg.203]


See other pages where Thermal influences is mentioned: [Pg.547]    [Pg.173]    [Pg.88]    [Pg.207]    [Pg.324]    [Pg.417]    [Pg.401]    [Pg.565]    [Pg.401]    [Pg.371]    [Pg.203]    [Pg.303]    [Pg.311]    [Pg.327]    [Pg.189]    [Pg.430]    [Pg.119]    [Pg.1544]    [Pg.311]    [Pg.169]    [Pg.141]    [Pg.26]    [Pg.456]    [Pg.458]    [Pg.202]    [Pg.775]   
See also in sourсe #XX -- [ Pg.28 , Pg.29 ]




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