Molecular rocket

Molecular Rockets and Shock Waves Induced by Nuclear... 

Moreover, novel applications of nuclear reactions involving technetium are being developed. Among them, multitracer utilization, molecular rocket reactions and shock wave enhancement phenomena are up-to-date examples. All these aspects are presented in this review paper. 

In the past few years, the new concept of a molecular rocket reaction has been developed [42-47], The system designed for this purpose consists of a metallocene rocket and a cyclodextrin cannon which includes the metallocene molecule. The central metal atom of the enclosed metallocene is irradiated with... 

Matsue et al. [43] attempted to study the molecular rocket reaction in a ruthenocene-/ -cyclodextrin inclusion compound using the I00Ru y, p) "raTc reaction. They noticed a parallel relationship between chemical processes and nuclear-recoil-induced processes in the non-included ruthenocene compound, as shown in Fig. 9. In the nuclear-recoil-induced processes no dimerization can be observed because of the extremely low concentration of the product, whereas in the chemical processes dimerization is possible, as demonstrated by Apostolidis et al. [48]. When ruthenocene included in /J-cyclodextrin is irradiated with y-rays, a part of the ruthenocene molecule is converted to [TcCp2-] which escapes from the jS-cyclodextrin cavity. The [TcCp2] rocket thus produced can attack neighboring inclusion compounds so as to extract the enclosed ruthenocene molecules and abstract H or Cp (Cp cyclopentadienyl radical). This process is shown schematically in Fig. 10. 

Fig. 10. A metallocene molecular rocket extracting other metallocenes in neighboring inclusion complexes. As an example 100Ru(y, p) 99mTc reaction, which produces the " TeCp- radical, is shown [43]... 

H. Matsue et al. Japan Molecular rocket reaction of ruthenocene included in cyclodextrin... 

In principle, emission spectroscopy can be applied to both atoms and molecules. Molecular infrared emission, or blackbody radiation played an important role in the early development of quantum mechanics and has been used for the analysis of hot gases generated by flames and rocket exhausts. Although the availability of FT-IR instrumentation extended the application of IR emission spectroscopy to a wider array of samples, its applications remain limited. For this reason IR emission is not considered further in this text. Molecular UV/Vis emission spectroscopy is of little importance since the thermal energies needed for excitation generally result in the sample s decomposition. 

The ratio of rocket thrust to propellant mass flow, commonly called the specific impulse (/9p) of the propellant, represents a measure of the force developed per unit mass flow of propellant. From Eq. (2), it is apparent that high propellant-flame temperatures and low molecular-weight combustion products are required to produce high 7sp. 

C04-0156. Decaborane, Bio H14, was used as fuel for the Redstone rockets of the 1950s. Decaborane reacts violently with molecular oxygen according to the following equation ... 

Fossil fuels are nonrenewable, and combustion products contaminate the atmosphere. Consequently, scientists are searching for new sources of energy. One possibility is molecular hydrogen, which releases energy when it reacts with oxygen 2 H2(g) + 02(g) 2H2 0(/) + Energy Hydrogen powers the rockets of the space shuttle,... 

H0 can be calculated from the propellant composition, but He must be obtained by successive approximation, assuming that the final state of the exhaust gases is known. For present purposes, it is sufficient to note that H0 — He correlates well with the heat of explosion of the solid explosive. In order to obtain the maximum thrust from a rocket it is therefore necessary to achieve the highest combustion temperature, but also necessary to produce gases with the lowest mean molecular weight. 

Potassium perchlorate (KP KCIO4) is a weU-known oxidizer, used as an oxidizer component of black powder. Since KP produces potassium oxides and condensed products, the high molecular mass Mg of the combustion products is not favorable for its use as an oxidizer in rocket propellants. A mixture of 75 % KP with 25 % asphalt pitch was used as a rocket propellant named Galcit, which was the original prototype of a composite propellant in the 1940 s. Potassium chlorate (KCIO3) is also a crystalline oxidizer, and although it has a lower oxygen content compared... 

Table 10.7 shows the physicochemical properties of the crystalHne materials used as oxidizers. Potassium and sodium are combined with nitrate or perchlorate to form stabilized crystalline oxidizers. Metal oxides are formed as their combustion products. On the other hand, ammonium ions are combined with nitrate or perchlorate to form stabilized crystalline oxidizers such as NH4NO3 and NH4CIO4 without metal atoms. When these oxidizers are decomposed, no solid products are formed. As discussed in Section 10.1.1, for the oxidizers used for propulsion, such as in propellants for rockets and guns, the molecular mass of the combustion products needs to be as low as possible. 

The molecular mass of the combustion products in the ramburner is increased by the formation of the oxidized metal particles. However, the temperature in the ramburner is also increased by the oxidation. The results of thermochemical calculations indicate that the specific impulse generated by the combustion in the ramburner is more dependent on the average combustion temperature than the average molecular mass of the products when metal particles are added. Table 15.4 shows the heats of combustion and the major oxidized products of the soHd particles used in ducted rockets. 

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