5,864 research outputs found
Ignition of sounding rocket motors with hand-pumped air
Method demonstrates inexpensive, safe, and foolproof concept for solid propellant rocket motors, using simple handpump to deliver air. Flueric ignition was accomplished using system without stored energy and with complete absence of electrical energy and wiring
Measurement of low-pT D+ meson production cross section at CDF
We report a measurement of the number of low-pT D+ mesons
produced in proton-antiproton collisions at 1.96TeV center-of-mass energy, using the full data set collected by the CDF experiment at the Tevatron collider during Run II. The measurement is performed in a yet unexplored low transverse momentum range, down to 1.5 GeV/c. The actual QCD theory cannot predict the behavior of the strong interactions in the low transferred-four-momentum region because in these kinematic conditions the strong coupling constant is of the order of unity. Thus, a perturbative expansion is not useful. At present, several phenomenological models have been proposed, but they are able to describe only a few aspects of the observed physical quantities and not the full complexity. Experimental results in these conditions are then crucial to test new QCD models. The measurement of the differential cross section at low pT plays an important role in this context allowing refinement of current knowledge
Enhancing the Understanding of Anatomy Through the Coloration and Plastination of Anatomical Specimens
Articlehttp://deepblue.lib.umich.edu/bitstream/2027.42/96980/1/UMURF-Issue05_2008-AMarchese.pd
Hybrid Photonic Antennae Based on Mesoporous Silica Frameworks
This contribution describes design, preparation and physico-chemical characterization of a new photo-stable hybrid antenna based on mesoporous SBA-15 silica. Concepts of host-guest chemistry are applied in such a way that one or more photoactive guest molecules are incorporated into the silica channels and on the outer surface, acting as energy harvesting and transferring units. The presented composite system be-haves as efficient Förster resonance energy transfer (FRET) pair and shows high photoluminescence and stability towards photodegradation, representing an important step forward in the search for new efficient materials with opto-electronic applications.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3549
The eastern boundary of the Gulf Stream recirculation
A meridionally aligned thermocline front near 60W in the subtropical North Atlantic is revealed by the 1992 Trident data set. The front separates saltier thermocline water to the east from less salty water to the west. The eastern water is subjected to excess evaporation of the subtropics, while the western water is fed by lower salinity Gulf Stream water, which derives water from the wet tropical Atlantic. It is suggested that the front marks the eastern edge of the Gulf Stream recirculation cell, hence refer to it as the recirculation front. The surface layer displays a fan-like T/S scatter above the 18°C Subtropical Mode Water, with the fresher surface water located west of the recirculation front, and a subsurface salinity maximum to the east. In the lower thermocline (8 to 12°C) there is a step-like salinity increase of about 0.04 toward the east as measured along isotherms, producing two modes in the T/S scatter. At the intermediate water level (approximately in the 4 to 8°C range) the extent of the low salinity Antarctic Intermediate Water and salty Mediterranean outflow water are also reflected in the position of the recirculation front. That the front marks the easternmost extent of the Gulf Stream recirculation is supported by the potential vorticity, which reveals a region of high homogeneous values within the recirculation cell. East of the front, the potential vorticity field is sloped along isopycnals indicating the meridional flow of the Sverdrup interior. Mapping of the recirculation front using archived data reveals that it extends deep into the subtropical convergence zone (STCZ), a region whose fronts have all been previously attributed to Ekman convergence
Hybrid Photonic Antennae Based on Mesoporous Silica Frameworks
This contribution describes design, preparation and physico-chemical characterization of a new photo-stable hybrid antenna based on mesoporous SBA-15 silica. Concepts of host-guest chemistry are applied in such a way that one or more photoactive guest molecules are incorporated into the silica channels and on the outer surface, acting as energy harvesting and transferring units. The presented composite system be-haves as efficient Förster resonance energy transfer (FRET) pair and shows high photoluminescence and stability towards photodegradation, representing an important step forward in the search for new efficient materials with opto-electronic applications.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3549
Ubiquitination differentially regulates clathrin-dependent internalization of protease-activated receptor-1
Protease-activated receptor-1 (PAR1), a G protein–coupled receptor (GPCR) for thrombin, is irreversibly activated by proteolysis. Consequently, PAR1 trafficking is critical for the fidelity of thrombin signaling. PAR1 displays constitutive and agonist-induced internalization, which are clathrin and dynamin dependent but are independent of arrestins. The clathrin adaptor AP2 (adaptor protein complex-2) is critical for constitutive but not for activated PAR1 internalization. In this study, we show that ubiquitination negatively regulates PAR1 constitutive internalization and specifies a distinct clathrin adaptor requirement for activated receptor internalization. PAR1 is basally ubiquitinated and deubiquitinated after activation. A PAR1 lysineless mutant signaled normally but was not ubiquitinated. Constitutive internalization of ubiquitin (Ub)-deficient PAR1 was markedly increased and inhibited by the fusion of Ub to the cytoplasmic tail. Ub-deficient PAR1 constitutive internalization was AP2 dependent like the wild-type receptor. However, unlike wild-type PAR1, AP2 was required for the internalization of activated Ub-deficient receptor, suggesting that the internalization of ubiquitinated PAR1 requires different endocytic machinery. These studies reveal a novel function for ubiquitination in the regulation of GPCR internalization
A critical analysis of the hydrino model
Recently, spectroscopic and calorimetric observations of hydrogen plasmas and
chemical reactions with them have been interpreted as evidence for the
existence of electronic states of the hydrogen atom with a binding energy of
more than 13.6 eV. The theoretical basis for such states, that have been dubbed
hydrinos, is investigated. We discuss both, the novel deterministic model of
the hydrogen atom, in which the existence of hydrinos was predicted, and
standard quantum mechanics. Severe inconsistencies in the deterministic model
are pointed out and the incompatibility of hydrino states with quantum
mechanics is reviewed.Comment: 9 page
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