1,235 research outputs found
Effect of polymer properties and adherend surfaces on adhesion
The surface properties associated with good adhesive joints were evaluated in terms of application of adhesive bonding in aerospace technology. The physical and chemical nature was determined of Ti and Al adherend surfaces after various surface treatments, and the effects on fracture surfaces of high temperature aging, and variations in amide, anhydride, and solvent during polymer synthesis. The effects were characterized of (1) high temperature during shear strength testing, (2) fiber-reinforced composites as adherends, (3) acid/base nature of adherends, (4) aluminum powder adhesive filler, and (5) bonding pressure
Boundary Condition on Electron Temperature for Antiforce Current Bearing Waves
In our investigation of breakdown waves, we apply a one-dimensional, three-component, steady-state fluid model. The wave is considered to be shock fronted and the electrons are assumed to be the main element in propagation of the wave. In our fluid model, the electron gas temperature is assumed to be large enough to sustain the wave motion. Our set of fluid equations is composed of the equations of conservation of mass, momentum and energy plus the Poisson’s equation. This investigation involves breakdown waves for which a large current exist in the vicinity of the wave front. Existence of current behind the wave front alters the equation of conservation of energy and also the Poisson’s equation. Therefore, the boundary conditions at the shock front will change as well. For current bearing breakdown waves we will derive the appropriate boundary condition for electron temperature, and using the new boundary condition, we will integrate the fluid dynamical equations through the dynamical transition region of the wav
Study of Beauty Hadron Decays into Pairs of Charm Hadrons
First observations of the decays Λ[0 over b] → Λ[+ over c]D[− over (s)] are reported using data corresponding to an integrated luminosity of 3 fb[superscript −1] collected at 7 and 8 TeV center-of-mass energies in proton-proton collisions with the LHCb detector. In addition, the most precise measurement of the branching fraction B(B[0 over s] → D[superscript +]D[− over s]) is made and a search is performed for the decays B[0 over (s)] → Λ[+ over c]Λ[− over c]. The results obtained are
B(Λ[0 over b] → Λ[+ over c]D[superscript −])/B(Λ[0 over b] → Λ[+ over c]D[− over s]) = 0.042 ± 0.003(stat) ± 0.003(syst), ⎡⎣B(Λ[0 over b] → Λ[+ over c]D[− over s]) over B([¯ over B[superscript 0] → D[superscript +]D[− over s])⎤⎦/⎡⎣B(Λ[0 over b] → Λ[+ over c]π[superscript −]) over B([¯ over B[superscript 0] → D[superscript +]π[superscript −])⎤⎦ = 0.96 ± 0.02(stat) ± 0.06(syst), B(B[0 over s] → D[superscript +]D[− over s])/B([¯ over B][superscript 0] → D[superscript +]D[− over s]) = 0.038 ± 0.004(stat) ± 0.003(syst), B([¯ over B][superscript 0] → Λ[+ over c]Λ[− over c])/B([¯ over B][superscript 0] → D[superscript +]D[− over s]) < 0.0022[95% C.L.], B(B[0 over s] → Λ[+ over c]Λ[− over c])/B(B[0 over s] → D[superscript +]D[− over s]) < 0.30[95% C.L.].
Measurement of the mass of the Λ[0 over b] baryon relative to the [¯ over B][superscript 0] meson gives M(Λ[0 over b]) − M([¯ over B][superscript 0]) = 339.72 ± 0.24(stat) ± 0.18(syst) MeV/c[superscript 2]. This result provides the most precise measurement of the mass of the Λ[0 over b] baryon to date.National Science Foundation (U.S.
Amelioration of bleomycin-induced lung fibrosis in hamsters by dietary supplementation with taurine and niacin: biochemical mechanisms.
Interstitial pulmonary fibrosis induced by intratracheal instillation of bleomycin (BL) involves an excess production of reactive oxygen species, unavailability of adequate levels of NAD and ATP to repair the injured pulmonary epithelium, and an overexuberant lung collagen reactivity followed by deposition of highly cross-linked mature collagen fibrils resistant to enzymatic degradation. In the present study, we have demonstrated that dietary supplementation with taurine and niacin offered almost complete protection against the lung fibrosis in a multidose BL hamster model. The mechanisms for the protective effect of taurine and niacin are multifaceted. These include the ability of taurine to scavenge HOCl and stabilize the biomembrane; niacin's ability to replenish the BL-induced depletion of NAD and ATP; and the combined effect of taurine and niacin to suppress all aspects of BL-induced increases in the lung collagen reactivity, a hallmark of interstitial pulmonary fibrosis. It was concluded from the data presented at this Conference that the combined treatment with taurine and niacin, which offers a multipronged approach, will have great therapeutic potential in the intervention of the development of chemically induced interstitial lung fibrosis in animals and humans
Gendered endings: Narratives of male and female suicides in the South African Lowveld
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s11013-012-9258-y. Copyright @ Springer Science+Business Media, LLC 2012.Durkheim’s classical theory of suicide rates being a negative index of social solidarity downplays the salience of gendered concerns in suicide. But gendered inequalities have had a negative impact: worldwide significantly more men than women perpetrate fatal suicides. Drawing on narratives of 52 fatal suicides in Bushbuckridge, South Africa, this article suggests that Bourdieu’s concepts of ‘symbolic violence’ and ‘masculine domination’ provide a more appropriate framework for understanding this paradox. I show that the thwarting of investments in dominant masculine positions have been the major precursor to suicides by men. Men tended to take their own lives as a means of escape. By contrast, women perpetrated suicide to protest against the miserable consequences of being dominated by men. However, contra the assumption of Bourdieu’s concept of ‘habitus’, the narrators of suicide stories did reflect critically upon gender constructs
A magnetically-driven piston pump for ultra-clean applications
A magnetically driven piston pump for xenon gas recirculation is presented.
The pump is designed to satisfy extreme purity and containment requirements, as
is appropriate for the recirculation of isotopically enriched xenon through the
purification system and large liquid xenon TPC of EXO-200. The pump, using
sprung polymer gaskets, is capable of pumping more than 16 standard liters per
minute (SLPM) of xenon gas with 750 torr differential pressure.Comment: 6 pages, 5 figure
Differential branching fraction and angular analysis of decays
The differential branching fraction of the rare decay is measured as a function of , the
square of the dimuon invariant mass. The analysis is performed using
proton-proton collision data, corresponding to an integrated luminosity of 3.0
\mbox{ fb}^{-1}, collected by the LHCb experiment. Evidence of signal is
observed in the region below the square of the mass. Integrating
over 15 < q^{2} < 20 \mbox{ GeV}^2/c^4 the branching fraction is measured as
d\mathcal{B}(\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^-)/dq^2 = (1.18 ^{+
0.09} _{-0.08} \pm 0.03 \pm 0.27) \times 10^{-7} ( \mbox{GeV}^{2}/c^{4})^{-1},
where the uncertainties are statistical, systematic and due to the
normalisation mode, , respectively.
In the intervals where the signal is observed, angular distributions are
studied and the forward-backward asymmetries in the dimuon ()
and hadron () systems are measured for the first time. In the
range 15 < q^2 < 20 \mbox{ GeV}^2/c^4 they are found to be A^{l}_{\rm FB} =
-0.05 \pm 0.09 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)} and A^{h}_{\rm FB} =
-0.29 \pm 0.07 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)}.Comment: 27 pages, 10 figures, Erratum adde
Observation of the decay
The first observation of the decay is reported. The
study is based on a sample of proton-proton collisions corresponding to
of integrated luminosity collected with the LHCb detector. The
significance of the signal is standard deviations. The branching fraction
is measured to be , where the third uncertainty comes from the
branching fraction that is used as a normalisation.
In addition, the charge asymmetries of and
, which are control channels, are measured to be and , respectively. All results are consistent with
theoretical expectations
First observation and amplitude analysis of the decay
The decay is observed in a data sample
corresponding to of collision data recorded by the LHCb
experiment during 2011 and 2012. Its branching fraction is measured to be
where the uncertainties are statistical, systematic and from
the branching fraction of the normalisation channel , respectively. An amplitude analysis of the resonant
structure of the decay is used to measure the
contributions from quasi-two-body ,
, and
decays, as well as from nonresonant sources. The
resonance is determined to have spin~1.Comment: 39 pages, 10 figures, submitted to Phys. Rev. D. Updated following
erratum 10.1103/PhysRevD.93.11990
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