7,412 research outputs found
Optical Spectroscopy to Determine Intermediate Combustion Product Radicals in a Hydrocarbon Fueled Rocket Engine Exhaust Plume
With the prospect of hydrocarbon-fueled rocket engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from these hydrocarbon fuels are of great interest. The effect of several diatomic molecular radicals, such as Carbon Monoxide, Molecular Carbon, Methylene Radical, Cyanide or Cyano Radical, Hydroxyl, and Nitric Oxide, needs to be identified and the effects of their band systems on the spectral region from 300 nm to 850 nm determined. This work shows the effect of different engine operating parameters, oxidizer-to-fuel ratio and chamber pressure, and different optical alignments, different lines-of-sight and fields-ofview, on the spectral signature of the engine exhaust plume of a small hydrocarbonfueled test engine. Computational results, along with experimental results of an extensive test program are presented
Optical Spectroscopy to Determine Intermediate Combustion Product Radicals in a Hydrocarbon Fueled Rocket Engine Exhaust Plume
With the prospect of hydrocarbon-fueled rocket engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from these hydrocarbon fuels are of great interest. The effect of several diatomic molecular radicals, such as Carbon Monoxide, Molecular Carbon, Methylene Radical, Cyanide or Cyano Radical, Hydroxyl, and Nitric Oxide, needs to be identified and the effects of their band systems on the spectral region from 300 nm to 850 nm determined. This work shows the effect of different engine operating parameters, oxidizer-to-fuel ratio and chamber pressure, and different optical alignments, different lines-of-sight and fields-ofview, on the spectral signature of the engine exhaust plume of a small hydrocarbonfueled test engine. Computational results, along with experimental results of an extensive test program are presented
Examination of actin and microtubule dependent APC localisations in living mammalian cells
Abstract (provisional)
Background
The trafficking of the adenomatous polyposis coli (APC) tumour suppressor protein in mammalian cells is a perennially controversial topic. Immunostaining evidence for an actin-associated APC localisation at intercellular junctions has been previously presented, though live imaging of mammalian junctional APC has not been documented.
Results
Using live imaging of transfected COS-7 cells we observed intercellular junction-associated pools of GFP-APC in addition to previously documented microtubule-associated GFP-APC and a variety of minor localisations. Although both microtubule and junction-associated populations could co-exist within individual cells, they differed in their subcellular location, dynamic behaviour and sensitivity to cytoskeletal poisons. GFP-APC deletion mutant analysis indicated that a protein truncated immediately after the APC armadillo repeat domain retained the ability to localise to adhesive membranes in transfected cells. Supporting this, we also observed junctional APC immunostaining in cultures of human colorectal cancer cell line that express truncated forms of APC.
Conclusions
Our data indicate that APC can be found in two spatially separate populations at the cell periphery and these populations can co-exist in the same cell. The first localisation is highly dynamic and associated with microtubules near free edges and in cell vertices, while the second is comparatively static and is closely associated with actin at sites of cell-cell contact. Our imaging confirms that human GFP-APC possesses many of the localisations and behaviours previously seen by live imaging of Xenopus GFP-APC. However, we report the novel finding that GFP-APC puncta can remain associated with the ends of shrinking microtubules. Deletion analysis indicated that the N-terminal region of the APC protein mediated its junctional localisation, consistent with our observation that truncated APC proteins in colon cancer cell lines are still capable of localising to the cell cortex. This may have implications for the development of colorectal cancer
Effective natural nodulation of peanuts in Queensland
In field experilnents, peanuts nodulated naturally in both a scrub and a forest soil at Kingaroy. Seed and soil inoculations were attempted, but it was difficult to superimpose the inoculum strain on the existing soil rhizobial population. There was a yield response to some inoculation treatments on new land with lower rhizobial count but not on land cropped previously to peanuts. Glasshouse tests confirmedthat the majority of field isolates of peanut rhizobia were effective in nitrogen fixation. Natural transfer of rhizobia on seed was recorded.
It was concluded that inoculation of peanuts was unlikely to be adopted in this peanut growing district
Distance measures to compare real and ideal quantum processes
With growing success in experimental implementations it is critical to
identify a "gold standard" for quantum information processing, a single measure
of distance that can be used to compare and contrast different experiments. We
enumerate a set of criteria such a distance measure must satisfy to be both
experimentally and theoretically meaningful. We then assess a wide range of
possible measures against these criteria, before making a recommendation as to
the best measures to use in characterizing quantum information processing.Comment: 15 pages; this version in line with published versio
Generation of Hyperentangled Photons Pairs
We experimentally demonstrate the first quantum system entangled in every
degree of freedom (hyperentangled). Using pairs of photons produced in
spontaneous parametric downconversion, we verify entanglement by observing a
Bell-type inequality violation in each degree of freedom: polarization, spatial
mode and time-energy. We also produce and characterize maximally hyperentangled
states and novel states simultaneously exhibiting both quantum and classical
correlations. Finally, we report the tomography of a 2x2x3x3 system
(36-dimensional Hilbert space), which we believe is the first reported photonic
entangled system of this size to be so characterized.Comment: 5 pages, 3 figures, 1 table, published versio
Structure and giant magnetoresistance of granular Co-Cu nanolayers prepared by cross-beam PLD
A series of Co_xCu_{100-x} (x = 0, 40...75, 100) layers with thicknesses
in-between 13 nm and 55 nm were prepared on silicon substrates using cross-beam
pulsed laser deposition. Wide-angle X-ray diffraction (WAXRD), transmission
electron microscopy (TEM) and electrical transport measurements revealed a
structure consisting of decomposed cobalt and copper grains with grain sizes of
about 10 nm. The influence of cobalt content and layer thickness on the grain
size is discussed. Electron diffraction (ED) indicates the presence of an
intermetallic Co-Cu phase of Cu3Au structure-type. Thermal treatment at
temperatures between 525 K and 750 K results in the progressive decomposition
of Co and Cu, with an increase of the grain sizes up to about 100 nm. This is
tunable by controlling the temperature and duration of the anneal, and is
directly observable in WAXRD patterns and TEM images. A careful analysis of
grain size and the coherence length of the radiation used allows for an
accurate interpretation of the X-ray diffraction patterns, by taking into
account coherent and non-coherent scattering. The alloy films show a giant
magnetoresistance of 1...2.3 % with the maximum obtained after annealing at
around 725 K.Comment: 9 pages, 9 figure
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