5,852 research outputs found
Analysis of Organophosphorus Compounds. 1. Application of Iodine-Azide Reaction for Detection of Thiophosphoorganic Compounds in Thin-Layer Chromatography
Wydrukowano z dostarczonych Wydawnictwu UŁ gotowych materiałówZadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę
Helicity fractions of W bosons from top quark decays at NNLO in QCD
Decay rates of unpolarized top quarks into longitudinally and transversally
polarized W bosons are calculated to second order in the strong coupling
constant alpha_s. Including the finite bottom quark mass and electroweak
effects, the Standard Model predictions for the W boson helicity fractions are
F_L=0.687(5), F_+=0.0017(1), and F_-=0.311(5).Comment: 5 pages, 1 figur
Communication between inertial observers with partially correlated reference frames
In quantum communication protocols the existence of a shared reference frame
between two spatially separated parties is normally presumed. However, in many
practical situations we are faced with the problem of misaligned reference
frames. In this paper, we study communication between two inertial observers
who have partial knowledge about the Lorentz transformation that relates their
frames of reference. Since every Lorentz transformation can be decomposed into
a pure boost followed by a rotation, we begin by analysing the effects on
communication when the parties have partial knowledge about the transformation
relating their frames, when the transformation is either a rotation or pure
boost. This then enables us to investigate how the efficiency of communication
is affected due to partially correlated inertial reference frames related by an
arbitrary Lorentz transformation. Furthermore, we show how the results of
previous studies where reference frames are completely uncorrelated are
recovered from our results in appropriate limits.Comment: 9 pages, 3 figures, typos corrected, figures update
Effect of interlamellar spacing on the elastoplastic behavior of C70 pearlitic steel: Experimental results and self-consistent modeling
The effect of pearlite microstructure characteristics on strength and deformation of C70 pearlitic steel was investigated. Tensile tests under X-ray diffraction coupled with self-consistent model have been used to identify the role of interlamellar spacing on the ferrite plasticity parameters and residual stress induced by plasticity. Tests have been carried out on two pearlitic microstructures with interlamellar spacing Sp = 170 and 230 nm respectively. Ferrite critical shear stresses ðs0c ðaÞÞ are equal to 75–86 MPa for interlamellar spacing Sp = 230 nm and 105–120 MPa for interlamellar spacing Sp = 170 nm. Moreover, the compressive residual stress measured in ferrite phase is higher in elasto-plastically deformed sample (total strain of E11 = 1.2%) having larger interlamellar spacing (rR Fea ¼ 161 MPa for Sp = 230 nm and rR Fea ¼ 77 MPa for Sp = 170 nm)
Dark matter and dark energy as a effects of Modified Gravity
We explain the effect of dark matter (flat rotation curve) using modified
gravitational dynamics. We investigate in this context a low energy limit of
generalized general relativity with a nonlinear Lagrangian , where is the (generalized) Ricci scalar and is parameter
estimated from SNIa data. We estimate parameter in modified
gravitational potential .
Then we compare value of obtained from SNIa data with parameter
evaluated from the best fitted rotation curve. We find which
becomes in good agreement with an observation of spiral galaxies rotation
curve. We also find preferred value of from the combined
analysis of supernovae data and baryon oscillation peak. We argue that although
amount of "dark energy" (of non-substantial origin) is consistent with SNIa
data and flat curves of spiral galaxies are reproduces in the framework of
modified Einstein's equation we still need substantial dark matter. For
comparison predictions of the model with predictions of the CDM
concordance model we apply the Akaike and Bayesian information criteria of
model selection.Comment: Lectures given at 42nd Karpacz Winter School of Theoretical Physics:
Ladek, Poland, 6-11 Feb 200
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