The two axis motion simulator for the large space simulator at ESTEC (European Space Research and Technology Center)

The Large Space Simulator at the European Space Research and Technology Center (ESTEC) has been recently equipped with a motion simulator capable of handling test items of 5 tons mass and having a volume of 7m in diameter and a length of 7m. The motion simulator has a modular set-up. It consists of a spinbox as a basic unit on which the test article is mounted and which allows continuous rotation (spin) . This spinbox can be used in two operational configurations; the spin axis is vertical to 30 degrees when mounted on a gimbalstand; and the spin axis is horizontal when mounted on a turntable-yoke combination. The turntable provides rotation within plus or minus 90 degrees. This configuration allows one to bring a test article to all possible relative positions viv-a-vis the sun vector (which is horizontal in this case). The spinbox allows fast rotation between 1 to 6 rpm or slow rotation between 1 to 25 rotations per day as well as positioning within plus or minus 0.4 degrees accuracy

Analysis of boron carbides' electronic structure

The electronic properties of boron-rich icosahedral clusters were studied as a means of understanding the electronic structure of the icosahedral borides such as boron carbide. A lower bound was estimated on bipolaron formation energies in B12 and B11C icosahedra, and the associated distortions. While the magnitude of the distortion associated with bipolaron formation is similar in both cases, the calculated formation energies differ greatly, formation being much more favorable on B11C icosahedra. The stable positions of a divalent atom relative to an icosahedral borane was also investigated, with the result that a stable energy minimum was found when the atom is at the center of the borane, internal to the B12 cage. If incorporation of dopant atoms into B12 cages in icosahedral boride solids is feasible, novel materials might result. In addition, the normal modes of a B12H12 cluster, of the C2B10 cage in para-carborane, and of a B12 icosahedron of reduced (D sub 3d) symmetry, such as is found in the icosahedral borides, were calculated. The nature of these vibrational modes will be important in determining, for instance, the character of the electron-lattice coupling in the borides, and in analyzing the lattice contribution to the thermal conductivity

Tratamento de sementes armazenadas com pós inertes à base de terra de diatomáceas.

bitstream/CNPT-2010/40478/1/p-co113.pd

Pós inertes no controle das principais pragas de grãos armazenados.

bitstream/item/84119/1/CNPT-BOL.-PESQ.-8-02.pd

Spray pyrolysis of La0.6Sr0.4Co0.2Fe0.8O3-δ thin film cathodes

Spray pyrolysis has been used to prepare La0.6 Sr0.4Co0.2Fe0.8O3-δ thin film cathodes for solid oxide fuel cell (SOFC) applications. The films are polycrystalline with nano-meter sized grains and less than 1 μm in thickness. Deposition parameters for film deposition have been established. The ratio of deposition temperature to solvent boiling point is found to be the most important processing parameter that determines whether a crack free homogeneous and coherent film is obtained. The morphology can be tailored by the deposition parameters. Annealing at 650∘C for four hours in air results in coherent films of the desired perovskite phase. The films are potential cathodes for thin film micro-solid oxide fuel cell

Spray pyrolysis of La0.6Sr0.4Co0.2Fe0.8O3-δ thin film cathodes

Spray pyrolysis has been used to prepare La0.6 Sr0.4Co0.2Fe0.8O3-δ thin film cathodes for solid oxide fuel cell (SOFC) applications. The films are polycrystalline with nano-meter sized grains and less than 1 μm in thickness. Deposition parameters for film deposition have been established. The ratio of deposition temperature to solvent boiling point is found to be the most important processing parameter that determines whether a crack free homogeneous and coherent film is obtained. The morphology can be tailored by the deposition parameters. Annealing at 650∘C for four hours in air results in coherent films of the desired perovskite phase. The films are potential cathodes for thin film micro-solid oxide fuel cell

Variable geometry inlet design for scram jet engine

The present invention relates to an improved variable geometry inlet for a scram jet engine having at least one combustor module. The variable geometry inlet comprises each combustor module having two sidewalls. Each of the sidewalls has a central portion with a thickness and a tapered profile forward of the central portion. The tapered profile terminates in a sharp leading edge. The variable geometry inlet further comprises each module having a lower wall and a movable cowl flap positioned forward of the lower wall. The movable cowl flap has a leading edge and the leading edges of the sidewalls intersect the leading edge of the cowl flap

P2X7 Receptor Primes IL-1β and the NLRP3 Inflammasome in Astrocytes Subjected to Mechanical Strain

Inflammatory responses play a key role in many neural pathologies, with localized signaling from non-immune cells making critical contributions. The NLRP3 inflammasome is an important component of innate immune signaling and can link neural insult to chronic inflammation. Stimulation of the NLRP3 inflammasome is a two-stage process. The priming stage involves upregulation of the biosynthesis of the structural components while activation results in their assembly into the actual inflammasome complex and subsequent activation. The priming step can be rate limiting and can connect insult to chronic inflammation but our knowledge of the signals that regulate NLRP3 inflammasome priming in sterile inflammatory conditions is limited. This study examined the link between mechanical strain and inflammasome priming in neural systems. Transient non-ischemic elevation of intraocular pressure (IOP) increased mRNA for inflammasome components IL-1β, NLRP3, ASC, CASP1 and IL-6 in rat and mouse retinas. The P2X7 receptor was implicated in the in vivo mechanosensitive priming of IL-1β and IL-6 transcription and translation. In vitro experiments with optic nerve head astrocytes demonstrated enhanced expression of the IL-1β and IL-6 genes following stretching or swelling. The increase in IL-1β expression was inhibited by degradation of extracellular ATP with apyrase, blocking pannexin hemichannels with carbenoxolone, probenecid or 10Panx1 peptide, P2X7 receptor antagonists (BBG, A839977 or A740003) as well inhibition of the NFκB transcription factor with Bay 11-7082. The swelling-dependent fall in expression of the NFκB inhibitor IκB-α was reduced by treatment of cells with A839977 and in P2X7 knockout mice. In summary, our data suggest that mechanical trauma to the retina results in priming of the NLRP3 inflammasome components and upregulated IL-6 expression and release. This was dependent upon ATP release through pannexin hemichannels and autostimulation of the P2X7 receptor. Since the P2X7 receptor can also trigger inflammasome activation it appears to have a central role in linking mechanical strain to neuroinflammation

3 ns single-shot read-out in a quantum dot-based memory structure

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 104, 053111 (2014) and may be found at https://doi.org/10.1063/1.4864281.Fast read-out of two to six charges per dot from the ground and first excited state in a quantum dot (QD)-based memory is demonstrated using a two-dimensional electron gas. Single-shot measurements on modulation-doped field-effect transistor structures with embedded InAs/GaAs QDs show read-out times as short as 3 ns. At low temperature (T = 4.2 K) this read-out time is still limited by the parasitics of the setup and the device structure. Faster read-out times and a larger read-out signal are expected for an improved setup and device structure