Three dimensional analysis and measurement of the flow in a three bladed rocket pump inducer

Three dimensional analysis and measurement of flow in three bladed pump inducer for liquid rocket engin

Investigations of three dimensional flow characteristics in a three bladed rocket pump inducer

Because of the long and narrow passages between the blades of a rocket pump inducer, major effects from turbulence and viscosity make the flow through such a device truly three-dimensional and therefore difficult to measure or predict. To investigate the flow characteristics, conventional and three-dimensional hot-wire probe measurements were conducted in a model inducer 3 ft in diameter. Blade-to-blade variation of the three components of velocity at the exit and the corresponding turbulence intensities were obtained by means of hotwire probes aligned in the three coordinate directions. Analysis of the three-dimensional inviscid flow field led to qualitative prediction of the flow characteristics. Extensive measurements and theoretical analyses of the flow field showed that blade blockage, viscosity, and blade boundary layer interactions are the dominant influences on flow in this type of turbomachinery

Copper Heat Exchanger for the External Auxiliary Bus-Bars Routing Line in the LHC Insertion Regions

The corrector magnets and the main quadrupoles of the LHC dispersion suppressors are powered by a special superconducting line (called auxiliary bus-bars line N), external to the cold mass and housed in a 50 mm diameter stainless steel tube fixed to the cold mass. As the line is periodically connected to the cold mass, the same gaseous and liquid helium cools both the magnets and the line. The final sub-cooling process (from around 4.5 K down to 1.9 K) consists in the phase transformation from liquid to superfluid helium. Heat is extracted from the line through the magnets via their point of junction. In dispersion suppressor zones, approximately 40 m long, the sub-cooling of the line is slightly delayed with respect to the magnets. This might have an impact on the readiness of the accelerator for operation. In order to accelerate the process, a special heat exchanger has been designed. It is located in the middle of the dispersion suppressor portion of the line. Its main function consists in providing a local point of heat extraction, creating two additional lambda fronts that propagate in opposite directions towards the extremities of the line. Both the numerical model and the sub-cooling analysis are presented in the paper for different configurations of the line. The design, manufacturing and integration aspects of the heat exchanger are described

Phylogeography of Rattus norvegicus in the South Atlantic Ocean

Acknowledgments Funding for sample collection was provided by the Shackleton Scholarship Fund, Antarctic Research Trust, the Wyoming Biodiversity Institute, PVE/CAPES (Proposal 235453) and Fundação para a Ciência e a Tecnologia (SFRH/BPD/88854/2012). Thanks to Martin Collins, Andy Black, Darren Christie and the Government of South Georgia and South Sandwich Islands for the provision of samples from South Georgia, Annalea Beard for providing the rat sample from St Helena Island, Joaquim Tapisso, Rita Monarca and Ana Cerveira for samples from Portugal, and Emily Puckett for help validating South American SNP haplotypes. Funding for DNA sequencing was provided by Island LandCare, the University of Auckland. Thanks to two anonymous reviewers for the constructive comments.Peer reviewedPublisher PD

Recalcitrance of polychlorinated biphenyls to biodegradation by phanerochaete chrysosporium in soil

The white rot fungus Phanerochaete chrysosporium has been shown in the past to effectively degrade a number of chlorinated aromatic compounds. Previous investigators (Eaton, D. C., Mineralization of Polychlorinated Biphenyls by Phanerochaete chrysosporium, a Lignolytic Fungus , Enz. Microb. Technol., 7, 194-196 (1985); Bumpus, J. A., Tien, M., Wright, D., and Aust, S. D., Oxidation of Persistent Environmental Pollutants by White Rot Fungus , Science, 228, 1434-1436 (1985)) have also claimed that this fungus is capable of mineralizing polychlorinated biphenyls (PCBs) in submerged cultures under stationary conditions. Therefore, the objective of this work was to study the biodegradation activity of the fungus in soils contaminated with PCBs. The results obtained so far indicate however that no significant degradation of PCBs in contaminated soil or sand occurs. Several types of experiments were conducted in which different parameters were varied: type of PCBs, amount and type of inoculum, type of solid support matrix, and concentration of some key nutrients. In most of the experiments, the amount of PCB recovered from the soil after the exposure to the fungus was lower than the initial amount. However, the relative concentrations of the PCBs congeners before and after the fungal treatment was the same in both cases. Since biodegradation typically results in the attack on some preferential congeners of the PCB mixture rather than a uniform, across-the-board mineralization, the results obtained so far appear to indicate that the fungus does not biodegrade PCBs. Furthermore, experiments in which the fungus was exposed to soil contaminated with 2,4,6-trichlorophenol (TCP), used as control experiments, showed that, in sand, this compound was degraded, whereas under the same conditions, PCBs would not undergo any degradation at all. In similar experiments conducted in soil, no degradation of PCBs was detected, but it is difficult to determine if degradation of TCP had occurred

Didemnin B: Comparative study and conformational approach in solution

A comparative study of isodideimnine-1 and didemnin B is presented using spcctroecopic methods, partial degradation and partial synthesis. This leads to the conclusion of the presence of a single depsipeptide, namely didemnin B, with (3S,4R,5S) isostatine instead of the previous statine residue. An attempt to determine the whole conformation in solution of didemnin B by using 2D-NMR is also described

Colloidal stability of tannins: astringency, wine tasting and beyond

Tannin-tannin and tannin-protein interactions in water-ethanol solvent mixtures are studied in the context of red wine tasting. While tannin self-aggregation is relevant for visual aspect of wine tasting (limpidity and related colloidal phenomena), tannin affinities for salivary proline-rich proteins is fundamental for a wide spectrum of organoleptic properties related to astringency. Tannin-tannin interactions are analyzed in water-ethanol wine-like solvents and the precipitation map is constructed for a typical grape tannin. The interaction between tannins and human salivary proline-rich proteins (PRP) are investigated in the framework of the shell model for micellization, known for describing tannin-induced aggregation of beta-casein. Tannin-assisted micellization and compaction of proteins observed by SAXS are described quantitatively and discussed in the case of astringency

Total synthesis and biological evaluation of the tetramic acid based natural product harzianic acid and its stereoisomers

Financial support for this project was provided by Cancer Research UK (Grant No. C21383/A6950)The bioactive natural product harzianic acid was prepared for the first time in just six steps (longest linear sequence) with an overall yield of 22%. The identification of conditions to telescope amide bond formation and a Lacey-Dieckmann reaction into one pot proved important. The three stereoisomers of harzianic acid were also prepared, providing material for comparison of their biological activity. While all of the isomers promoted root growth, improved antifungal activity was unexpectedly associated with isomers in the enantiomeric series opposite that of harzianic acid.Publisher PDFPeer reviewe