Experimental determination of turbulence in a GH2-GOX rocket combustion chamber

The intensity of turbulence and the Lagrangian correlation coefficient for a gaseous rocket combustion chamber have been determined from the experimental measurements of the tracer gas diffusion. A combination of Taylor's turbulent diffusion theory and Spalding's numerical method for solving the conservation equations of fluid mechanics was used to calculate these quantities. Taylor's theory was extended to consider the inhomogeneity of the turbulence field in the axial direction of the combustion chamber. An exponential function was used to represent the Lagrangian correlation coefficient. The results indicate that the maximum value of the intensity of turbulence is about 15% and the Lagrangian correlation coefficient drops to about 0.12 in one inch of the chamber length

Thiyl radicals are co-products of dinitrosyl iron complex (DNIC) formation.

Thiyl radicals are detected by EPR as co-products of dinitrosyl iron complex (DNIC) formation. In demonstrating that DNIC formation generates RS˙ in a NO rich environment, these results provide a novel route for S-nitroso thiol formation

Alien Registration- Ohara, Albert R. (Presque Isle, Aroostook County)

https://digitalmaine.com/alien_docs/33617/thumbnail.jp

Rocketdyne PSAM: In-house enhancement/application

The development was initiated of the Probabilistic Design Analysis (PDA) Process for rocket engines. This will enable engineers a quantitative assessment of calculated reliability during the design process. The PDA will help choose better designs, make them more robust, and help decide on critical tests to help demonstrate key reliability issues to aid in improving the confidence of the engine capabilities. Rockedyne's involvement with the Composite Loads Spectra (CLS) and Probabilistic Structural Analysis Methodology (PSAM) contracts started this effort and are key elements in the on-going developments. Internal development efforts and hardware applications complement and extend the CLS and PSAM efforts. The completion of the CLS option work and the follow-on PSAM developments will also be integral parts of this methodology. A brief summary of these efforts is presented

Dynamics of Dinitrosyl Iron Complex (DNIC) Formation with Low Molecular Weight Thiols.

Dinitrosyl iron complexes (DNICs) are ubiquitous in mammalian cells and tissues producing nitric oxide (NO) and have been argued to play key physiological and pathological roles. Nonetheless, the mechanism and dynamics of DNIC formation in aqueous media remain only partially understood. Here, we report a stopped-flow kinetics and density functional theory (DFT) investigation of the reaction of NO with ferrous ions and the low molecular weight thiols glutathione (GSH) and cysteine (CysSH) as well as the peptides WCGPC and WCGPY to produce DNICs in pH 7.4 aqueous media. With each thiol, a two-stage reaction pattern is observed. The first stage involves several rapidly established pre-equilibria leading to a ferrous intermediate concluded to have the composition FeII(NO)(RS)2(H2O)x (C). In the second stage, C undergoes rate-limiting, unimolecular autoreduction to give thiyl radical (RS•) plus the mononitrosyl Fe(I) complex FeI(NO)(RS)(H2O)x following the reactivity order of CysSH > WCGPC > WCGPY > GSH. Time course simulations using the experimentally determined kinetics parameters demonstrate that, at a NO flux characteristic of inflammation, DNICs will be rapidly formed from intracellular levels of ferrous iron and thiols. Furthermore, the proposed mechanism offers a novel pathway for S-nitroso thiol (RSNO) formation in a biological environment

Enhancement of Superconducting Transition Temperature due to the strong Antiferromagnetic Spin Fluctuations in Non-centrosymmetric Heavy-fermion Superconductor CeIrSi3 :A 29Si-NMR Study under Pressure

We report a 29Si-NMR study on the pressure-induced superconductivity (SC) in an antiferromagnetic (AFM) heavy-fermion compound CeIrSi3 without inversion symmetry. In the SC state at P=2.7-2.8 GPa, the temperature dependence of the nuclear-spin lattice relaxation rate 1/T_1 below Tc exhibits a T^3 behavior without any coherence peak just below Tc, revealing the presence of line nodes in the SC gap. In the normal state, 1/T_1 follows a \sqrt{T}-like behavior, suggesting that the SC emerges under the non-Fermi liquid state dominated by AFM spin fluctuations enhanced around quantum critical point (QCP). The reason why the maximum Tc in CeIrSi3 is relatively high among the Ce-based heavy-fermion superconductors may be the existence of the strong AFM spin fluctuations. We discuss the comparison with the other Ce-based heavy-fermion superconductors.Comment: 4 pages, 5 figures, To be published in Phys. Rev. Let

Bridge over Olduvai Gorge: Capacity building and conservation of lithics and fossils

This paper explores decision-making processes involved in the conservation of lithics and fossils excavated at Olduvai Gorge, Tanzania. The site is renowned for discoveries of early humans from the Palaeolithic period, lithics and fossils that document the evolutionary history of humans, vertebrate fauna and their environment over the last two million years. Excavated specimens are treated in situ, at the field laboratory and at the UCL Institute of Archaeology in London. Factors such as accessibility, ease of transportation and preparation, disposal, Tg and toxicity of resins, and ease of re-treatability are considered to decide what can be used in treatments and how. Frequently used materials include Paraloid B-44 and cyclododecane for temporary consolidation and Paraloid B-44 for adhesion and gap-filling. We have found that, in such complex contexts, the more one engages with colleagues across the disciplines and local community groups, the smoother, stronger and more sustainable one’s efforts become

Spin Susceptibility of Noncentrosymmetric Heavy-fermion Superconductor CeIrSi3 under Pressure: 29Si-Knight Shift Study on Single Crystal

We report 29Si-NMR study on a single crystal of the heavy-fermion superconductor CeIrSi3 without an inversion symmetry along the c-axis. The 29Si-Knight shift measurements under pressure have revealed that the spin susceptibility for the ab-plane decreases slightly below Tc, whereas along the c-axis it does not change at all. The result can be accounted for by the spin susceptibility in the superconducting state being dominated by the strong antisymmetric (Rashba-type) spin-orbit interaction that originates from the absence of an inversion center along the c-axis and it being much larger than superconducting condensation energy. This is the first observation which exhibits an anisotropy of the spin susceptibility below Tc in the noncentrosymmetric superconductor dominated by strong Rashba-type spin-orbit interaction.Comment: 4 pages, 4 figures, Accepted for publication in Phys. Rev. Let