4 research outputs found
EFFECTS OF FLUORINE-CONTAINING SPECIES ON THE IGNITION AND COMBUSTION OF BORON PARTICLES: EXPERIMENT AND THEORY
The ignition and combustion of isolated boron particles in fluorine-containing environments were investigated both experimentally and theoretically. Boron particles (1-mum amorphous and 3-mum crystalline) were ignited and burned completely in the post-flame region of a multi-diffusion flat-flame burner, which provided a uniform zone of combustion products of CH4/NF3/O-2/N-2 mixtures. In fluorinated environments, no clear distinction was observed to define a two-stage combustion process, a characteristic feature of boron oxidation without fluorine. At 1,780 K, boron ignition required a higher oxidizer concentration in non-fluorinated environments than in fluorinated environments. BF was found to increase the total burning times (t(b)) of boron particles; whereas F significantly reduced tb. A theoretical model was developed for simulating the combustion of an isolated boron particle in fluorine-containing environments. The oxide layer removal process was modeled using a reaction mechanism, which considers vaporization process of B2O3(BO)(n) mixture and four global surface reactions of oxide layer with O-2, H2O, F, and HF. The major products during the oxide removal process were found to be OBF, FBOH, HBO2, and BO2. The "Clean" boron combustion model includes four global surface reactions of O-2, H2O, F, and BF with boron. BF3, OBF, HBO2, and B2O2 are the major products during the "clean" boron combustion stage. Predicted tb are in good agreement with the measured data in the current study and other published experimental data in the literature. The calculated results show that both oxide layer removal and "clean" boron burning rates increase significantly in the presence of atomic fluorine
DEVELOPMENT OF PASSIVATED PYROPHORIC METAL POWDERS (HAFNIUM AND ZIRCONIUM) WITH REDUCED ELECTROSTATIC DISCHARGE (ESD) SENSITIVITY
Li–Pd–Rh-D2O electrochemistry experiments at elevated voltage
In 2013, the U.S. Navy disclosed an electrochemistry procedure intended to produce MeV-energy nuclear particles, based on eV-energy electrical inputs, which may be indicative of a new scientific phenomenon. This work is based on the 2013 disclosure and shows initial evidence validating the prior claims of nuclear particle generation. Additionally, several variations on the 2013 electrochemical recipe are made in order to find a highly repeatable recipe for future replications by other teams. The experiments described here produced dense collections of tracks in solid-state nuclear track detectors, radio frequency (RF) emissions, and anomalous heat flux, which are indicative of potential nuclear, or unusual chemical, reactions. Experimental results include tracks in solid-state nuclear track detectors similar in size to tracks produced by 4.7 MeV alpha particles on identical detectors exposed to radioactive Th-230; RF pulses up to 6 dB above the noise floor, which indicate that these signals were likely not background noise and not caused by known chemical reactions; and heat flux of 10 s of kJ, measured to 6σ significance, over and above input electrical energy, indicative of unknown exothermic reactions. Six out of six nuclear track detectors, utilized in experiments and interrogated for tracks post-experiment, produced positive results that our team attributes to thousands of individual particle impacts in dense clusters, likely with energies between 0.1 and 20 MeV. Similar nuclear particle, thermal, and RF results have separately appeared in prior reports, but in this work, all three categories of anomalous behavior are reported. Results indicate that the 2013 procedure may be a useful guide toward a set of highly repeatable reference experiments, showing initial but not overwhelming evidence of a new scientific phenomenon. Repeatable recipes are shared so that other groups may replicate and extend the present work